Devices and methods for increasing blood perfusion to distal limbs

Abstract

An apparatus and method divert blood flow from a first blood vessel to a second blood vessel and maintain blood flow in the first blood vessel. The apparatus includes a first segment and a second segment. The first segment is configured to be anchored in the first blood vessel. The first segment includes a window to allow blood to flow into the first segment, through the window, and distally within the first blood vessel. The second segment is configured to be anchored in the second blood vessel. The second segment is configured to allow blood to flow into the first segment, through the second segment, and into the second blood vessel.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Provisional Patent Application No. 62 / 929,366, filed November 1, 2019; U.S. Provisional Patent Application No. 63 / 004,763, filed April 3, 2020; and U.S. Provisional Patent Application No. 63 / 072,423, filed September 4, 2020, each of which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] This application relates to methods and systems used in percutaneous interventional procedures. Specifically, this application relates to methods and systems for providing or maintaining fluid flow through bodily channels such as heart chambers and blood vessels. Background Technology

[0004] Minimally invasive percutaneous surgery, or "keyhole" surgery, is a surgical technique in which a surgical device is inserted into a patient's body cavity through a small incision made in the skin. This form of surgery has become increasingly popular because it allows patients to tolerate less surgical discomfort while retaining the benefits of traditional surgery. Patients treated with this technique are less likely to experience discomfort, require general anesthesia, experience trauma, and have a lower risk of infection, and their recovery time can be significantly reduced compared to traditional surgical procedures.

[0005] For example, keyhole surgery can be used for laparoscopic surgery and for the treatment of cardiovascular diseases. In the treatment of cardiovascular diseases, balloon angioplasty can be used as an alternative to open-heart surgery to treat partially occluded coronary arteries. In balloon angioplasty, a balloon catheter is inserted into an artery, usually near the patient's groin, and guided to the patient's heart. The balloon at the distal end of the catheter in the heart is inflated to widen or enlarge the occluded blood vessel, thereby helping to restore blood flow to the heart tissue. A tubular support device (e.g., a stent) can be deployed at the site of the blockage to prevent future occlusion (restenosis) or collapse of the vessel. For example, the stent can be an expandable metal mesh carried on the balloon of a balloon catheter, or it can be self-expanding. When the balloon inflates, the expandable stent expands so that the stent pushes against the vessel wall. As the stent reaches its expanded position, for example by plastic deformation or by means of a mechanical locking mechanism, the stent is positioned to maintain its expanded shape, thereby forming a resilient stent or support in the vessel. This support structure (e.g., a stent) supports and expands the vessel wall to maintain the path of blood flow through the blood vessel. Self-expanding stents are also available, which are held in a collapsed state for transport through the artery via a suitably modified catheter, and take on an expanded state when deployed at the site of blockage. For example, the catheter may include a retaining sleeve that holds the stent in a compressed or unexpanded state. Once the sleeve is removed from or retracted from the stent, the stent expands to support and expand the vessel wall.

[0006] Balloon angioplasty is not always a suitable procedure, such as in acute cases or in cases of complete coronary artery occlusion. In these cases, the usual treatment is coronary artery bypass grafting. Coronary artery bypass grafting is an open-chest procedure or direct cardiac visualization procedure and typically involves grafting a healthy vessel onto the coronary artery to bypass the blockage and restore blood flow to the coronary tissue. The healthy vessel is usually a vein obtained from the patient's leg or arm during the bypass procedure. To perform this procedure, the patient's heart must be exposed by opening the chest cavity, separating the sternum, and cutting open the pericardium surrounding the heart, resulting in significant surgical trauma.

[0007] Traditional coronary artery bypass surgery is not always an option. Certain patients are unsuitable candidates for traditional coronary artery bypass surgery due to low or high risk of recovery from the significant trauma of the procedure, high risk of infection, lack of healthy blood vessels available for bypass grafting, significant comorbidities, and the anticipated long and complex recovery time associated with open-heart surgery. For example, factors such as diabetes, age, obesity, and smoking can exclude a subset of candidates who truly need this treatment. Summary of the Invention

[0008] This application provides methods and systems for overcoming certain deficiencies and / or improving percutaneous approaches and systems. For example, according to several embodiments, the methods and systems described herein can improve the targeting and localization of treatment application, which can advantageously provide treatment via percutaneous techniques to patients unsuitable for more invasive surgery. Some embodiments described herein can provide fluid flow in channels such as coronary and / or peripheral vessels by creating bypasses using minimally invasive percutaneous surgical techniques.

[0009] In some examples, a firing conduit for targeting a second blood vessel from a first blood vessel includes a conduit comprising a proximal portion and a distal portion, the distal portion comprising a flat, radiopaque marker. The radiopaque marker may be rectangular. The conduit may include a pinhole. The conduit may include a needle configured to extend through the pinhole.

[0010] The distal portion of the catheter may be curved. The marker may not follow the curvature of the distal portion of the catheter. The pinhole may be proximal to the marker. The pinhole may be distal to the marker. The pinhole may at least partially overlap with the marker.

[0011] The needle orifice may be on a first side of the distal portion of the catheter. A marker may be on a second side of the distal portion of the catheter. The first side may be identical to the second side. The first side may be opposite to the second side. The distal end of the needle extending from the needle orifice may be longitudinally aligned with the radiopaque marker. The needle may contain a profile. The needle may slide through a needle lumen. The needle lumen may contain a shape complementary to the profile (e.g., to reduce longitudinal movement of the needle during advancement).

[0012] The marker may comprise a first transmissive material and a second opaque material coupled to the first transmissive material. The second opaque material may be coupled to the first transmissive material by one or more of the following methods: cladding, plating, chemical vapor deposition, atomic layer deposition, screen printing, coating, bonding, or sputtering. The second opaque material may be polished or flattened after being coupled to the first transmissive material.

[0013] The ratio of the length to the width of the marker can be between 1 / 1 and 5 / 1.

[0014] The marker can have a thickness between 0.001 mm and 1 mm. The marker can also have a thickness between 1 nm and 10 μm.

[0015] A tool kit may include a firing conduit and a target conduit. The target conduit may include an expandable member. The expandable member may include a strangulator. The expandable member may include a mesh. The expandable member may include a radiopaque material. The target conduit may include a first radiopaque marker. The target conduit may include a second radiopaque marker longitudinally spaced from the first radiopaque marker.

[0016] In some examples, a firing conduit for targeting a second blood vessel from a first blood vessel includes a conduit comprising a proximal portion and a distal portion, the distal portion including a pinhole and a flat, rectangular radiopaque marker. The flat, rectangular radiopaque marker disappears under fluorescence examination after rotation to provide information about the rotational alignment of the firing conduit. The firing conduit further includes a needle configured to extend through the pinhole.

[0017] In some examples, a catheter includes a flat, radiopaque marker. The catheter may be a firing catheter for targeting a second vessel from a first vessel. The catheter may include a distal portion containing the flat, radiopaque marker. The radiopaque marker may be rectangular. The catheter may include a pinhole. The catheter may include a needle configured to extend through the pinhole. The distal portion of the catheter may be curved. The marker may not follow the curvature of the distal portion of the catheter. The pinhole may be proximal to the marker. The pinhole may be distal to the marker. The pinhole may at least partially overlap with the marker. The pinhole may be on a first side of the distal portion of the catheter. The marker may be on a second side of the distal portion of the catheter. The first side may be identical to the second side. The first side may be opposite to the second side. The distal end of the needle extending from the pinhole may be longitudinally aligned with the radiopaque marker. The needle may include a shaped element. The needle may slide through the needle lumen. The needle lumen may contain a shape complementary to the profile (e.g., to reduce longitudinal movement of the needle during needle advance). A tool kit may include a firing cannula and a target cannula. The target cannula may include an expandable member. The expandable member may include a strangulator. The expandable member may include a mesh. The expandable member may include a radiopaque material. The target cannula may include a first radiopaque marker. The target cannula may include a second radiopaque marker longitudinally spaced from the first radiopaque marker.

[0018] In some examples, a method of aligning a catheter involves rotating the catheter in a first blood vessel. The catheter includes a flat, radiopaque marker. Rotation continues until the marker has a thickness indicating the rotational alignment of the catheter. The thickness is visible under fluorescence examination. The thickness may be less than a certain value. The thickness can be indicated by a thin (e.g., minimum thickness) line. The radiopaque marker may be rectangular.

[0019] The method may include rotating the catheter in a first blood vessel until the marker has thickness (e.g., minimum thickness) under fluorescence examination and is on one side of the catheter. The method may further include longitudinally advancing the catheter until the marker is proximal to a second catheter in a second blood vessel. The second catheter may include radiopaque features visible under fluorescence examination. The radiopaque features of the second catheter visible under fluorescence examination may include an expandable member. The expandable member may include a decanter. The expandable member includes a mesh.

[0020] The method may further include extending a needle out of the catheter after rotating the catheter. Extending the needle out of the catheter may involve exiting the first blood vessel and entering a second blood vessel different from the first blood vessel. Aligning the catheter may involve aligning the needle. Extending the needle out of the catheter may involve passing through the interstitial tissue between the first blood vessel and the second blood vessel.

[0021] The method may further include extending a guidewire through a needle and into a second blood vessel. The method may further include entanglement of the guidewire in a second catheter within the second blood vessel. The entangled guidewire may include an expandable member that closes the second catheter. The method may further include moving the second catheter to detect a corresponding movement of the guidewire. The method may further include moving the second catheter to move the guidewire through the second blood vessel.

[0022] A catheter system may include a tubular body and at least one of a targeting system, an expandable member, or a fluid injection port coupled to the tubular body.

[0023] In some embodiments, a catheter system for identifying bifurcations in a blood vessel includes, or optionally comprises substantially, the following components: a tubular body; a targeting system coupled to the tubular body; an expandable member configured to attach to the sidewall of the blood vessel in an expanded state to occlude the blood vessel; and a fluid injection port configured to inject radiopaque fluid into the blood vessel proximal to the expandable member in an expanded state, such that the radiopaque fluid converges near the expandable member and provides visualization of the blood vessel and its branching vessels.

[0024] An expandable member can be coupled to a tubular body. The tubular body may include a fluid injection port. The conduit system may further include a second tubular body. The expandable member can be coupled to the second tubular body. The second tubular body may include a fluid injection port. The targeting system may include an ultrasonic transducer. The targeting system may include an omnidirectional ultrasonic transducer.

[0025] In some embodiments, a catheter system includes or optionally comprises substantially the following components: a tubular body; a targeting system coupled to the tubular body; and an expandable member.

[0026] An expandable member can be coupled to a tubular body. The catheter system may further include a second tubular body. The expandable member can be coupled to the second tubular body. The expandable member can be configured to attach to the sidewall of a blood vessel to occlude the blood vessel. The catheter system may further include a fluid injection port. The tubular body may include a fluid injection port. The catheter system may further include a second tubular body containing the fluid injection port. The targeting system may include an ultrasound transducer. The targeting system may include an omnidirectional ultrasound transducer.

[0027] In some embodiments, a catheter system includes or optionally comprises substantially the following components: a tubular body; a targeting system coupled to the tubular body; and a fluid injection port.

[0028] The tubular body may include a fluid injection port. The catheter system may further include a second tubular body, which also includes a fluid injection port. The catheter system may further include an expandable member. The expandable member may be coupled to the tubular body. The catheter system may further include a second tubular body. The expandable member may be coupled to the second tubular body. The expandable member may be configured to attach to the sidewall of a blood vessel to occlude the blood vessel. The targeting system may include an ultrasound transducer. The targeting system may include an omnidirectional ultrasound transducer.

[0029] In some embodiments, a conduit system includes, or optionally comprises substantially, a tubular body, a fluid injection port, and an expandable member.

[0030] The tubular body may include a fluid injection port. The catheter system may further include a second tubular body containing the fluid injection port. An expandable member may be coupled to the tubular body. The catheter system may further include a second tubular body. The expandable member may be coupled to the second tubular body. The expandable member may be configured to attach to the sidewall of a blood vessel to occlude the blood vessel. The catheter system may further include a targeting system. The targeting system may include an ultrasound transducer. The targeting system may include an omnidirectional ultrasound transducer. A method for identifying bifurcation may include inserting the catheter system into a first blood vessel, positioning the catheter system at a first location, expanding the expandable member to occlude the first blood vessel, and delivering a contrast material into the first blood vessel. The contrast material may converge near the expandable member. The method may further include reviewing the shape of the contrast material in the first blood vessel under fluorescence examination.

[0031] In some embodiments, a method for identifying bifurcation includes, or optionally substantially comprises, inserting a catheter system into a first blood vessel and positioning the catheter system at a first location. The catheter system includes an expandable member and a fluid injection port. The method further includes expanding the expandable member to occlude the first blood vessel and delivering a contrast material from the fluid injection port. The contrast material converges near the expandable member. The method further includes examining the shape of the contrast material in the first blood vessel under fluorescence examination.

[0032] A single catheter may include an expandable member and a fluid injection port. A first catheter may include an expandable member, and a second catheter may include a fluid injection port. Expanding the expandable member may include providing fluid flow through an expandable lumen in fluid communication with the expandable member. Expanding the expandable member may include dilating a first vascular tract. The contrast material may include at least one of an iodine-based contrast agent and a barium sulfate-based contrast agent. Delivering the contrast material may include dilating the first vascular tract. Examining the shape of the contrast material may include identifying the presence of at least one of bifurcated and branched vascular tracts. The method may further include repositioning the catheter system if at least one of bifurcated and branched vascular tracts is present. The method may further include extending a needle from another catheter in a second vascular tract if at least one of bifurcated and branched vascular tracts is not present. Extending the needle may include exiting the second vascular tract, passing through the interstitial tissue between the second and first vascular tracts, and entering the first vascular tract. The method may further include advancing a guidewire through the needle. The catheter system may include a capture element configured to guide the guidewire into a guidewire lumen.

[0033] The catheter system may include a targeting system. Positioning the catheter system at a first location may include a complementary targeting system from another catheter in a second vessel. The targeting system may include an ultrasound receiver. The complementary targeting system may include an ultrasound transmitter. The ultrasound receiver may include an omnidirectional ultrasound transducer. The ultrasound transmitter may include a directional ultrasound transducer. The method may further include enlarging the fistula.

[0034] The method may further include deploying a prosthesis at least partially in a fistula between a second vessel and a first vessel. After deployment of the prosthesis, blood can be delivered from the first vessel to the second vessel through the prosthesis. The method may further include, after deployment of the prosthesis, lining the first vessel with a stent graft, including a collateral vessel covering the first vessel. Lining the first vessel with a stent graft may include lining the first vessel with multiple stent grafts. Lining the first vessel with multiple stent grafts may include first deploying the most distal stent graft among the multiple stent grafts, and last deploying the most proximal stent graft among the multiple stent grafts. After lining the first vessel with multiple stent grafts, the proximal edge of the most distal stent graft among the multiple stent grafts may overlap the distal edge of the next most distal stent graft among the multiple stent grafts. After lining the first vessel with multiple stent grafts, the proximal edge of the most proximal stent graft among the multiple stent grafts may overlap the distal edge of the prosthesis.

[0035] The method may further include incompetent closure of the valve in the first blood vessel. Incompetent closure of the valve in the first blood vessel may occur after lining the blood vessel with a stent graft. Incompetent closure of the valve in the first blood vessel may include advancing a reverse valve knife through the prosthesis and advancing the reverse valve knife distally in the first blood vessel to disenabling the valve. Incompetent closure of the valve in the first blood vessel may include advancing a bidirectional valve knife in a radially compressed state to approach the valve, radially expanding the bidirectional valve knife to a radially expanded state, and in the radially expanded state, advancing the bidirectional valve knife distally and retracting it proximally in the first blood vessel to disenabling the valve. Radially expanding the bidirectional valve knife may include retracting the sheath proximally and advancing the bidirectional valve knife distally. A method for causing valve insufficiency in a blood vessel may include advancing a bidirectional valve knife in a radially compressed state to approach the valve, radially expanding the bidirectional valve knife to a radially expanded state, and in the radially expanded state, advancing the bidirectional valve knife distally and retracting it proximally in the blood vessel to disenabling the valve.

[0036] In some embodiments, a method of modifying a blood vessel includes declosing valves in the blood vessel and covering a collateral tube of the blood vessel. The method comprises or optionally consists substantially of the following steps: lining the blood vessel with a stent graft, including covering the collateral tube of the blood vessel, and declosing valves in the blood vessel after lining the blood vessel with a stent graft.

[0037] The method may further include deploying a prosthesis at least partially in a fistula between a second blood vessel and the blood vessel. After deployment of the prosthesis, blood can be diverted from the second blood vessel to the blood vessel through the prosthesis. Lining the blood vessel with a stent graft may be done after deployment of the prosthesis. The method may further include widening the fistula. The method may further include advancing a needle from the second blood vessel into the blood vessel to form a fistula. The advancing needle may include targeting a first catheter in the blood vessel with a second catheter in the second blood vessel. The second catheter may include an ultrasound transmitter. The first catheter may include an ultrasound receiver. Targeting the catheter in the blood vessel with a catheter in the second blood vessel may include targeting the ultrasound receiver with the ultrasound transmitter. The method may further include advancing a guidewire through the needle. The catheter system in the blood vessel may include a capture element configured to guide the guidewire into a guidewire lumen. Lining the blood vessel with a stent graft may include lining the blood vessel with multiple stent grafts. Lining the blood vessel with multiple stent grafts may include first deploying the most distal stent graft among the multiple stent grafts and last deploying the most proximal stent graft among the multiple stent grafts. After lining a blood vessel with multiple stent grafts, the proximal edge of the most distal stent graft among the multiple stent grafts may overlap the distal edge of the next most distal stent graft among the multiple stent grafts. After lining a blood vessel with multiple stent grafts, the proximal edge of the most proximal stent graft among the multiple stent grafts may overlap the distal edge of the prosthesis in the fistula. Valve insufficiency in a blood vessel may involve distally advancing a reverse valve knife within the blood vessel to disenabling the valve. Valve insufficiency in a blood vessel may involve advancing a bidirectional valve knife in a radially compressed state to approach the valve, radially expanding the bidirectional valve knife to a radially expanded state, and in the radially expanded state, distally advancing the bidirectional valve knife and proximally retracting the bidirectional valve knife within the blood vessel to disenabling the valve. The radially expanding bidirectional valve knife may include proximally retracting the sheath and distally advancing the bidirectional valve knife. The method may further include promoting retrograde perfusion of blood into the toes. Promoting retrograde perfusion of blood into the toes can include expanding a first dilatable member in the medial plantar vein to occlude the medial plantar vein. Promoting retrograde perfusion of blood into the toes can include expanding a second dilatable member in the lateral plantar vein to occlude the lateral plantar vein. Promoting retrograde perfusion of blood into the toes can include increasing the hydrostatic pressure in the deep plantar venous arch. Increasing the hydrostatic pressure in the deep plantar venous arch can include deactivating the venous valves and allowing blood flow to reverse into the metatarsal veins.

[0038] In some embodiments, a method for promoting retrograde perfusion of blood into the toes includes, or optionally substantially comprises, the steps of: expanding a first dilatable member in a medial plantar vein to occlude the medial plantar vein, and increasing the hydrostatic pressure in the deep plantar venous arch. Increasing the hydrostatic pressure in the deep plantar venous arch may include disabling venous valves and enabling blood flow to reverse into the metatarsal veins. The method may further include expanding a second dilatable member in a lateral plantar vein to occlude the lateral plantar vein.

[0039] In some embodiments, a catheter system for facilitating retrograde perfusion of blood to the toes includes, or optionally comprises substantially, the following components: a first catheter including a first expandable member configured to expand in a medial plantar vein to occlude the medial plantar vein; and a second catheter including a second expandable member configured to expand in a lateral plantar vein to occlude the lateral plantar vein.

[0040] The first catheter can move longitudinally through the second catheter and the second expandable member. The first catheter may include an expandable lumen in fluid communication with the first expandable member. The second catheter may include an expandable lumen in fluid communication with the second expandable member. The first catheter may be configured to curve around a lateral plantar vein into a medial plantar vein.

[0041] In some embodiments, a bidirectional valvular blade includes, or optionally comprises substantially, a proximal portion; a distal portion; and a longitudinally spaced intermediate portion between the proximal and distal portions. The intermediate portion includes a blade facing distally and a blade facing proximally.

[0042] The intermediate section may include pillars, each pillar containing a distally facing blade and a proximally facing blade. The intermediate section may include multiple pillars. One of the multiple pillars may contain both a distally facing blade and a proximally facing blade. Each of the multiple pillars may contain both a distally facing blade and a proximally facing blade. At least one of the multiple pillars may contain a distally facing blade. At least one of the multiple pillars may contain a proximally facing blade. The intermediate section may contain three pillars. The three pillars may be uniformly circumferentially spaced. The intermediate section may be radially expandable. The intermediate section may be self-expanding after release from the sheath. The proximal section may be coupled to a propeller element. The intermediate section may be laser-cut (e.g., from a submersible tube or plate). At least one of the distally facing blade and the proximally facing blade may be rotatable relative to the periphery of the intermediate section.

[0043] In some embodiments, a method for causing valve incompetence in a blood vessel includes, or optionally substantially comprises, the following steps: advancing a bidirectional valve blade in a radially compressed state to approach the valve; radially expanding the bidirectional valve blade to a radially expanded state; and, in the radially expanded state, advancing the bidirectional valve blade distally and retracting it proximally in the blood vessel to disenabling the valve.

[0044] Advancing the bidirectional valvular knife close to the valve may include advancing the bidirectional valvular knife in the direction opposite to the natural fluid flow. Advancing the bidirectional valvular knife close to the valve may also include advancing the bidirectional valvular knife in the direction of the natural fluid flow. Advancing the bidirectional valvular knife close to the valve may include advancing the bidirectional valvular knife proximally to the valve. Advancing the bidirectional valvular knife close to the valve may also include advancing the bidirectional valvular knife distally to the valve.

[0045] In some embodiments, a catheter for capturing a guidewire includes or optionally comprises substantially the following parts: a catheter body; a capturing element; and a guidewire lumen in communication with the capturing element.

[0046] The capture element can be configured to be deployed distally from the catheter body. The capture element can also be configured to be deployed laterally from the catheter body. The capture element can have a collapsed state and an expanded state. The capture element can contain a shape memory material configured to change to an expanded state at body temperature. The capture element can have an angle between 110° and 150° in the expanded state. The guidewire lumen can contain an expanded portion adjacent to the capture element. The catheter can further contain an expandable element configured to expand the capture element. The expandable element can contain an inflatable member. The catheter body can contain an expandable lumen in fluid communication with the inflatable member. The expandable element can be movable relative to the catheter body.

[0047] In some embodiments, a method for causing valvular insufficiency includes the steps of forming a fistula between a first blood vessel and a second blood vessel. The first blood vessel may be an artery. The second blood vessel may be a vein. Forming the fistula includes inserting a first catheter into the first blood vessel. The first catheter includes an ultrasound transmitting transducer and a needle configured to extend radially from the first catheter. Forming the fistula further includes inserting a second catheter into the second blood vessel. The second catheter includes an ultrasound receiving transducer. Forming the fistula further includes transmitting an ultrasound signal from the ultrasound transmitting transducer and, after the ultrasound signal is received by the ultrasound receiving transducer, extending the needle from the first catheter. The extending needle includes exiting the first blood vessel, traversing the interstitial tissue between the first and second blood vessels, and entering the second blood vessel. The method further includes deploying a prosthesis at least partially in the fistula. After deployment of the implantable prosthesis, blood is diverted from the first blood vessel to the second blood vessel through the prosthesis. The method further includes causing valvular insufficiency in the second blood vessel. Causing valvular insufficiency in the second blood vessel includes cutting the valve using a reverse valve knife and lining the second blood vessel with a stent.

[0048] The stent may contain a covering or graft. The lining second vascular vessel may contain collateral vessels covering the second vascular vessel. The stent may be separate from the prosthesis. The stent may be spaced apart from the prosthesis along the length of the second vascular vessel. The stent may be integral with the prosthesis.

[0049] In some embodiments, a method for causing valvular insufficiency includes, or optionally substantially comprises, the following steps: forming a fistula between a first blood vessel and a second blood vessel. Forming the fistula includes inserting a catheter into the first blood vessel. The catheter includes a needle configured to extend radially from the first catheter. Forming the fistula further includes extending the needle from the first catheter. The extending needle includes exiting the first blood vessel, traversing the interstitial tissue between the first and second blood vessels, and entering the second blood vessel. The method further includes deploying a prosthesis, at least partially, in the fistula between the first and second blood vessels. After deployment of the implantable prosthesis, blood is diverted from the first blood vessel to the second blood vessel through the prosthesis. The method further includes causing valvular insufficiency in the second blood vessel. Causing valvular insufficiency in the second blood vessel includes at least one of the following: cutting the valve using a reverse valvular knife, inflating a balloon, dilating a temporary stent, and lining the second blood vessel with an implantable stent.

[0050] The implantable stent may include a covering or a graft. The lining second vessel may include a collateral vessel covering the second vessel. The implantable stent may be separate from the prosthesis. The implantable stent may be integral with the prosthesis. The first catheter may include an ultrasound emitting transducer. Fistula formation may involve inserting a second catheter into the second vessel, the second catheter including an ultrasound receiving transducer, emitting an ultrasound signal from the ultrasound emitting transducer, and extending a needle from the first catheter after the ultrasound signal is received by the ultrasound receiving transducer.

[0051] In some embodiments, a method of causing valvular insufficiency includes, or optionally substantially comprises, the steps of: deploying a prosthesis at least partially in a fistula between a first and a second blood vessel. Following deployment of the implantable prosthesis, blood is diverted from the first blood vessel to the second blood vessel through the prosthesis. The method further includes causing valvular insufficiency in the second blood vessel.

[0052] Valve regurgitation in a second blood vessel may involve cutting the valve using a reverse valvular knife. Valve regurgitation in a second blood vessel may involve lining the second blood vessel with a stent. The stent may include a covering or graft. Lining the second blood vessel may include a collateral canal covering the second blood vessel. The stent may be separate from the prosthesis. The stent may be spaced apart from the prosthesis along the length of the second blood vessel. The proximal segment of the stent may longitudinally overlap the distal segment of the prosthesis. The stent may be integral with the prosthesis. Valve regurgitation in a second blood vessel may involve cutting the valve using a reverse valvular knife and lining the second blood vessel with a stent. Valve regurgitation in a second blood vessel may include at least one of an inflatable balloon and a dilatational temporary stent. Valve regurgitation in a second blood vessel may include an inflatable balloon. Valve regurgitation in a second blood vessel may include a dilatational temporary stent.

[0053] In some embodiments, an implantable prosthesis for treating occlusion in a first blood vessel comprises or optionally consists substantially of: a plurality of filaments woven together to form a woven structure; a proximal end; a distal end; a sidewall between the proximal and distal ends; an inner lumen defined by the sidewall; and porosity sufficient to guide fluid flow through the inner lumen without substantially perfusing through the sidewall.

[0054] The porosity can be between about 0% and about 50%. The porosity can be between about 5% and about 50%. The prosthesis can be substantially free of graft material. The prosthesis can comprise a first longitudinal segment having porosity and a second longitudinal segment having a second porosity different from the first longitudinal segment. The second longitudinal segment can have parameters different from the first longitudinal segment. These parameters can include at least one of weave angle, filament diameter, filament material, weave structure diameter, weave structure shape, and supplementary support structure. The prosthesis can further comprise a third longitudinal segment between the first and second longitudinal segments. The third longitudinal segment can have parameters different from at least one of the first and second longitudinal segments. These parameters can include at least one of weave angle, filament diameter, filament material, weave structure diameter, weave structure shape, and supplementary support structure. The prosthesis can further comprise a supplementary support structure. The supplementary support structure can comprise a second plurality of filaments woven together to form a second weave structure, the second plurality of filaments having parameters different from the plurality of filaments. This parameter may include at least one of the following: weaving angle, filament diameter, weave structure diameter, and filament material. The supplementary support structure may include cut submersible tubes. Multiple filaments may include filaments comprising shape memory materials (e.g., nitinol) and filaments comprising biocompatible polymers (e.g., ) prosthesis.

[0055] In some embodiments, an implantable prosthesis for treating occlusion in a first blood vessel comprises, or optionally substantially comprises, the following: a proximal end; a distal end; a sidewall between the proximal and distal ends; a lumen defined by the sidewall; a first longitudinal segment configured to be anchored in a first body cavity; a second longitudinal segment configured to be anchored in a second body cavity; and a third longitudinal segment between the first and second longitudinal segments. At least one of the first and third longitudinal segments includes porosity sufficient to guide fluid flow through the lumen while substantially not perfusing through the sidewall.

[0056] Porosity can be between about 0% and about 50%. Porosity can be between about 5% and about 50%. The prosthesis can be substantially free of graft material. The second longitudinal segment can have parameters different from those of the first longitudinal segment. These parameters can include at least one of weaving angle, filament diameter, filament material, diameter, shape, and supplementary support structure. The third longitudinal segment can contain a second porosity different from the aforementioned porosity. The first longitudinal segment can be balloon-expandable. The second longitudinal segment can be self-expanding. The prosthesis can contain multiple filaments woven together to form a woven structure. The multiple filaments can include filaments comprising shape memory materials (e.g., nitinol) and filaments comprising biocompatible polymers (e.g., The prosthesis has a third longitudinal segment that may have at least one parameter different from that of the first and second longitudinal segments. This parameter may include at least one of the following: weave angle, filament diameter, filament material, diameter, shape, and supplementary support structure. The prosthesis may further include a supplementary support structure. The first longitudinal segment may be generally cylindrical and may have a first diameter; the second longitudinal segment may be generally cylindrical and may have a second diameter greater than the first diameter; and the third longitudinal segment may be truncated conical and may taper from the first diameter to the second diameter. The first longitudinal segment may be generally cylindrical and may have a first diameter; and the second and third longitudinal segments may be truncated conical and taper from the first diameter to a second diameter greater than the first diameter.

[0057] In some embodiments, an implantable prosthesis for treating occlusion in a first blood vessel comprises: a plurality of filaments woven together to form a woven structure; a proximal end; a distal end; a sidewall between the proximal and distal ends; an inner lumen defined by the sidewall; and a porosity between about 5% and about 50%.

[0058] The porosity can be configured to guide fluid flow substantially through the cavity. The prosthesis may include a first longitudinal segment and a second longitudinal segment, the first longitudinal segment having porosity and the second longitudinal segment having a second porosity different from the stated porosity.

[0059] In some embodiments, a kit includes a prosthesis and a fistula formation system. The kit may further include a device for disabling the valve. In some embodiments, a kit includes a prosthesis and a device for disabling the valve. The kit may include a prosthesis delivery system including the prosthesis. In some embodiments, a method includes deploying the prosthesis in a fistula between a first and a second blood vessel. The device for disabling the valve may include a reverse valve knife. The device for disabling the valve may include a balloon. The device for disabling the valve may include a venous stent. The venous stent may include a covering or graft. The venous stent may be integrated with the prosthesis.

[0060] In some embodiments, a method of diverting fluid flow from a first blood vessel to a second blood vessel includes deploying a prosthesis at least partially in a fistula between the first and second blood vessels, wherein the first blood vessel is occluded. The prosthesis comprises a plurality of filaments woven together to form a woven structure, the woven structure having a porosity of less than about 50%. After deployment of the implantable prosthesis, blood can be diverted through the prosthesis from the first blood vessel to the second blood vessel.

[0061] The first vessel may be an artery. The vessel passage may be a vein. The method may include enlarging the fistula. The first vessel may be substantially parallel to the second vessel. Deploying the prosthesis may include allowing the prosthesis to self-expand. Deploying the prosthesis may include a balloon-expandable prosthesis. Deploying the prosthesis may include deploying a woven structure and deploying a supplementary support structure. Deploying the supplementary support structure may be prior to deploying the woven structure. Deploying the supplementary support structure may be after deploying the woven structure. The supplementary support structure may include a second plurality of filaments woven into the second woven structure. The supplementary support structure may include cutting the hypotube. The method may further include forming a fistula. Forming a fistula may include inserting a transmitting catheter into the first vessel and inserting a target catheter into the second vessel. The transmitting catheter may include an ultrasound transmitting transducer and a needle configured to extend radially from the transmitting catheter. The target catheter may include an ultrasound receiving transducer. Forming a fistula may involve emitting an ultrasound signal from an ultrasound transmitting transducer, and during and until the ultrasound signal is received by an ultrasound receiving transducer, performing at least one of the following: rotating the transmitting catheter and longitudinally moving the transmitting catheter; and after the ultrasound signal is received by the ultrasound receiving transducer, extending a needle from the transmitting catheter, wherein the extending needle comprises: exiting a first blood vessel, traversing the interstitial tissue between the first and second blood vessels, and entering the second blood vessel. The method may further comprise causing valvular insufficiency in the second blood vessel. Causing valvular insufficiency in the second blood vessel may comprise cutting the valve using a reverse valvular knife. Causing valvular insufficiency in the second blood vessel may comprise inflating a balloon. Causing valvular insufficiency in the second blood vessel may comprise expanding a stent. Causing valvular insufficiency in the second blood vessel may comprise lining the second blood vessel with a stent. The stent may comprise a covering or graft. Lining the second blood vessel may comprise covering a collateral canal of the second blood vessel. The stent may be separate from the prosthesis. The stent may be spaced apart from the prosthesis along the length of the second blood vessel. The end of the stent can be abutted against the end of the prosthesis. A portion of the stent can longitudinally overlap a portion of the prosthesis. A portion of the stent can be radially inward of a portion of the prosthesis. This method can include expanding the stent after the prosthesis is deployed. A portion of the prosthesis can be radially inward of a portion of the stent. This method can include expanding the stent before the prosthesis is deployed. The stent can be integral with the prosthesis.

[0062] In some embodiments, an implantable prosthesis for maintaining the openness of anastomoses between arteries and veins in a lower limb includes: a first segment configured to reside in a lower limb artery, a second segment configured to reside in a lower limb vein, and a third segment longitudinally located between the first and second segments. The third segment is configured to maintain the openness of the anastomoses between the artery and vein.

[0063] The first segment can be configured to attach to the wall of a lower limb artery. The first segment may include barbs. The second segment can be configured to attach to the wall of a lower limb vein. The second segment may include barbs. At least one of the first, second, and third segments can be self-dilatating. At least one of the first, second, and third segments can be balloon-dilatating. The length of the second segment can be greater than the length of the first segment. The second segment can be configured to disable the valves of the lower limb vein. The second segment can be configured to cover a collateral vessel of the lower limb vein.

[0064] In some embodiments, a method of diverting fluid flow from a first vessel in a lower limb to a second vessel includes forming an orifice between the first and second vessels and dilating the orifice to form an anastomosis.

[0065] Forming the orifice may involve forcing a wire from the first vessel into the second vessel. Forming the orifice may involve inserting a needle transversely from the first vessel into the second vessel. Dilatating the orifice may involve dilatating the orifice using at least one balloon. Dilatating the orifice may involve using multiple balloons with progressively larger diameters. The first balloon of the multiple balloons may have a diameter of about 1.5 mm, and the last balloon of the multiple balloons may have a diameter of about 3 mm. The multiple balloons may include a first balloon with a diameter of about 1.5 mm, a second balloon with a diameter of about 2.0 mm, a third balloon with a diameter of about 2.5 mm, and a third balloon with a diameter of about 3.0 mm. Dilatating the orifice using multiple balloons may involve using progressively larger balloon inflation pressures. This method may not require (e.g., without or exempt from) placement of prostheses (e.g., without using stents, grafts, scaffolding, or other prostheses). The positions of the first and second vessels can be substantially maintained by the anatomical structures surrounding the first and second vessels. The method may further include placing a prosthesis in the anastomosis. Placing the prosthesis in the anastomosis may include anchoring the prosthesis in at least one of a first blood vessel and a second blood vessel. The first blood vessel may include the lateral plantar artery. The second blood vessel may include the lateral plantar vein.

[0066] In some embodiments, a catheter for snare a guidewire comprises, or optionally substantially comprises, a sheath and an expandable element. The expandable element is in a collapsed state when in the sheath and in an expanded state when exiting the sheath. The expandable element comprises a plurality of units configured to snare the guidewire.

[0067] The catheter may further include a guidewire sheath extending through a sheath and an expandable element. The proximal end of the expandable element may be coupled to the guidewire sheath. The expandable element may be configured to dilate a blood vessel upon deployment. The expandable element may be visible under fluorescence examination. The expandable element may include a strut defining a plurality of units. The strut may be deflectable if contacted by a needle. The catheter may further include an ultrasound receiving transducer. The ultrasound receiving transducer may be distal to the expandable element. The ultrasound receiving transducer may be longitudinally positioned between the proximal and distal ends of the expandable element. A method of capturing a guidewire may include inserting the catheter into a first blood vessel, dilating the expandable element to an expanded state within the first blood vessel, and extending a needle from a second blood vessel through interstitial tissue and into the first blood vessel between the proximal and distal ends of the expandable element. The needle extension may include extending through one of the plurality of units. The method may further include extending a guidewire through a needle and into an expandable element, and collapsing the expandable element toward a collapsed state. The collapsed expandable element may include a capture guidewire.

[0068] In some embodiments, a method of capturing a guidewire includes, or optionally substantially comprises, the steps of: expanding an expandable element to an expanded state in a first blood vessel, and extending a needle from a second blood vessel through interstitial tissue and into the first blood vessel between a proximal end and a distal end of the expandable element. The expandable element comprises a plurality of units. Extending the needle comprises extending through one of the plurality of units. The method further comprises extending a guidewire through the needle and into the expandable element, and collapsing the expandable element toward a collapsed state. The collapsed expandable element comprises capturing the guidewire.

[0069] The collapse expandable element may include a torsion expandable element. The expansion expandable element may include dilating a first blood vessel. Needle extension may include targeting the expandable element under fluorescence examination. The method may further include retracting the expandable element proximally. Retracting the expandable element proximally may include delivering a guidewire through the first blood vessel.

[0070] In some embodiments, a device for deploying a tubular structure includes, or optionally substantially comprises, a handle body, a knob, and a slider. The handle body includes a first segment having threads; a second segment longitudinally adjacent to and proximal to the first segment; and a longitudinal slot. The second segment is unthreaded. The knob has threads. The knob is located at the distal end of the first segment in an initial position. The slider is operably connected to the knob. The slider is coupled to a sheath. The knob is configured to rotate proximal to the handle body with respect to the first segment and to slide proximal to the handle body with respect to the second segment. The slider is configured to retract the sheath proximal to the sheath by a first amount during rotation of the knob and to retract the sheath proximal to the sheath by a second amount during sliding of the knob. The device is configured to fully deploy the tubular structure after the sheath has been retracted by the second amount.

[0071] The first amount can be less than the second amount. The first amount can be between 10% and 50% of the second amount. The tubular structure can contain a scaffold. The tubular structure can contain a scaffold graft.

[0072] In some embodiments, a method of deploying a tubular structure includes, or optionally substantially comprises, the following steps: rotating a knob about a handle body. Rotating the knob about the handle body includes retracting the sheath proximally and deploying a first amount of the tubular structure. The method further includes, after rotating the knob about the handle body, sliding the knob proximally along the handle body. Sliding the knob proximally along the handle body includes retracting the sheath proximally, thereby deploying a second amount of the tubular structure. The first and second amounts are the total amount of the tubular structure.

[0073] The first amount can be less than the second amount. The first amount can be between 10% and 50% of the second amount. The tubular structure can contain a scaffold. The tubular structure can contain a scaffold graft.

[0074] In some embodiments, a device for deploying a tubular structure includes, or optionally substantially comprises, the following parts: a sheath; a handle body; a knob including a worm gear with teeth; and a slider coupled to the sheath. The slider includes a first portion within the handle body; a second portion outside the handle body; and a worm including teeth configured to interact with the teeth of the worm gear. The slider is configured to retract the sheath proximally by a first amount during rotation of the knob, and is configured to retract the sheath proximally by a second amount during sliding of the slider. The device is configured to fully deploy the tubular structure after the sheath has been retracted by the second amount.

[0075] The first amount can be less than the second amount. The first amount can be between 10% and 50% of the second amount. The tubular structure can contain a support. The tubular structure can contain a support graft. The handle body can contain a longitudinal slot. The slider can contain a third portion extending through the longitudinal slot. The handle body can contain a second longitudinal slot. The slider can contain a fourth portion outside the handle body and a fifth portion extending through the second longitudinal slot. The fourth portion can be on the side of the handle body opposite to the second portion. The handle body can contain a shell that at least partially covers the second portion of the slider until the sheath can retract proximally to the first amount.

[0076] In some embodiments, a method of deploying a tubular structure includes, or optionally substantially comprises, the following steps: rotating a knob. Rotating the knob includes retracting the sheath proximally and deploying the tubular structure by a first amount. The method further includes, after rotating the knob, sliding a slider proximally along the handle body. Sliding the slider proximally along the handle body includes retracting the sheath proximally by a second distance and deploying the tubular structure by a second amount. The first and second amounts constitute the full amount of the tubular structure.

[0077] The first amount can be less than the second amount. The first amount can be between 10% and 50% of the second amount. The tubular structure can include a support. The tubular structure can include a support graft. The knob can include a worm gear containing teeth. The slider can include a worm containing teeth configured to interact with the teeth of the worm gear. The handle body can include a longitudinal slot. The slider can be included in a first portion within the handle body, a second portion outside the handle body, and a third portion extending through the longitudinal slot. The handle body can include a second longitudinal slot. The slider can be included in a fourth portion outside the handle body and a fifth portion extending through the second longitudinal slot. The fourth portion can be on the side of the handle body opposite the second portion. The slider retracting proximally can include gripping the second and fourth portions. The handle body can include a housing that at least partially covers the second portion of the slider until the sheath retracts proximally by the first amount. The axis of rotation of the knob can be transverse to the longitudinal axis of the handle body.

[0078] In some embodiments, a method of accessing the tibial vein of a subject includes, or optionally substantially comprises, positioning a first tourniquet above the knee of the leg, positioning a second tourniquet above the ankle of the leg, injecting a certain amount of contrast agent through the metatarsal vein, and using a fluorescence examination to prepare for venography to image the veins of the foot of the leg.

[0079] The first tourniquet can be a different type from the second tourniquet. The first tourniquet can be the same type as the second tourniquet. The first tourniquet can be the same size as the second tourniquet. The first tourniquet can be a different size than the second tourniquet. The method may further include positioning the subject in the opposite Trendel-Lombard position. The method may further include flattening the subject after injecting a contrast agent via the metatarsal vein. The contrast agent may contain a non-ionic contrast agent. The contrast agent may contain a mixture of contrast material and saline. The contrast agent may contain a 50 / 50 dilution of contrast material and saline. The amount of contrast agent may be between 5 mL and 50 mL. The metatarsal vein may be a dorsal metatarsal vein of the foot. The metatarsal vein may be a plantar metatarsal vein. The method may further include palpating the metatarsal vein. The method may further include using venography to select the tibial vein. The method may further include advancing a guidewire to the target tibial vein. The method may further include removing the second tourniquet. The method may further include tracing a functional catheter over the guidewire. Functional catheters may contain catheters for forming fistulas (e.g., target catheters, launch catheters). Functional catheters may contain a strangulator.

[0080] In some embodiments, a method of accessing a lateral plantar vein of a subject includes, or optionally substantially comprises, positioning a first tourniquet above the ankle of the leg, placing a needle in the medial marginal vein of the dorsum of the foot toward the toes of the foot, advancing a first guidewire into the first metatarsal vein of the foot, injecting a certain amount of contrast agent, and using a fluorescence examination to prepare for venography to image the vein of the foot of the leg.

[0081] The contrast agent may contain a nonionic contrast agent. The contrast agent may contain a mixture of contrast material and saline. The contrast agent may contain a 50 / 50 dilution of contrast material and saline. The amount of contrast agent may be between 5 mL and 50 mL. The method may further include selecting the larger of two lateral plantar veins using venography. The method may further include advancing a first guidewire to at least one of the transverse points or above the ankle, and using ultrasound to examine the veins on the sole of the foot to observe the location of the first guidewire. The method may further include advancing a first guidewire to at least one of the transverse points or above the ankle, using ultrasound to examine the veins on the sole of the foot to observe the location of the first guidewire, and entering the lateral plantar vein containing the first guidewire in the foot as distally as possible in the arch of the foot at the second entry site. The method may further include advancing a second guidewire into the lateral plantar vein. The method may further include advancing the second guidewire into the posterior tibial vein until the transverse point. The method may further include removing the first guidewire. The method may further include removing the tourniquet. The method may further include tracing a functional catheter over the guidewire. Functional catheters may contain catheters for forming fistulas (e.g., target catheters, launch catheters). Functional catheters may contain a strangulator.

[0082] In some embodiments, a method of performing an ascending venography procedure includes, or optionally substantially comprises, injecting a certain amount of contrast agent into the venous vascular system from the first metatarsal vein.

[0083] In some embodiments, a method of performing a descending venography procedure includes, or optionally substantially comprises, injecting a certain amount of contrast agent into the venous vascular system from the great saphenous vein toward the foot.

[0084] In some embodiments, a method of aligning a catheter for a venous arterialization procedure includes inserting a first catheter into a first blood vessel. The first catheter includes a pinhole, a radiopaque marker, and a needle, the pinhole being on a first side of the needle, the radiopaque marker being distal to the pinhole and on a second side of the first catheter opposite to the first side, and the needle being configured to extend through the pinhole. The radiopaque marker is visible under fluorescence examination. The method further includes inserting a second catheter into a second blood vessel. The second catheter includes a balloon. The method further includes inflating the balloon. The inflating balloon includes expanding the balloon using a radiopaque material visible under fluorescence examination. The method further includes longitudinally advancing the first catheter until the radiopaque marker is close to the second catheter in the second blood vessel, and aligning the pinhole of the first catheter with the second catheter. Aligning the pinhole includes rotating the first catheter in the first blood vessel such that the radiopaque marker changes between a first position and a second position. The method further includes monitoring the rotation of a radiopaque marker toward a second position to confirm rotational alignment of the needle orifice with the second conduit, and, after confirming rotational alignment, extending the needle from the needle orifice of the first conduit. The extension of the needle involves exiting the first vessel, passing through the interstitial tissue between the first and second vessels, and entering the second vessel.

[0085] The method may further include extending a guidewire through a needle and into a second blood vessel, and entangled the guidewire in a second catheter within the second blood vessel. The entangled guidewire may include an expandable member that closes the second catheter. The method may further include, after extending the guidewire, moving the second catheter to detect a corresponding movement of the guidewire to confirm the entanglement of the guidewire in the second catheter. The method may further include moving the second catheter to move the guidewire through the second blood vessel. Moving the second catheter to move the guidewire through the second blood vessel may include exiting the second blood vessel at a location within the foot.

[0086] In some embodiments, a method of aligning a catheter for a venous arterialization procedure includes inserting a first catheter into a first blood vessel. The first catheter includes a radiopaque marker and a needle extendable along an extension path. The method further includes inserting a second catheter into a second blood vessel. The second catheter includes an expandable member. The expandable member comprises a radiopaque material visible under fluorescence examination. The method further includes expanding the expandable member and aligning the needle of the first catheter with the second catheter. Aligning the needle includes rotating the first catheter in the first blood vessel such that the radiopaque marker changes between a first position and a second position. The method further includes monitoring the rotation of the radiopaque marker toward the second position to confirm rotational alignment of the needle extension path with the second catheter, and after confirming rotational alignment, extending the needle from the first catheter and along an extension path. Extending the needle includes exiting the first blood vessel, passing through the interstitial tissue between the first and second blood vessels, and entering the second blood vessel.

[0087] The method may further include extending a guidewire through a needle and into a second vessel. Extending the guidewire may include entanglement of the guidewire in an expandable member of the second catheter. The method may further include retracting the expandable member through the second vessel. Retracting the expandable member may include advancing the guidewire through the second vessel. Entangling the guidewire may include closing the expandable member of the second catheter. A radiopaque marker may be located on the side of the first catheter opposite to the needle extension path. A radiopaque marker may be located distal to the needle exit orifice. The second catheter may include a balloon. The balloon may be inflated using a radiopaque material.

[0088] In some embodiments, a method of aligning a catheter for a venous arterialization procedure includes inserting a first catheter into a first blood vessel. The first catheter includes a radiopaque marker and a needle. The method further includes inserting a second catheter into a second blood vessel. The second catheter includes an expandable member. The method further includes expanding the expandable member. The expanded expandable member includes a radiopaque material. The method further includes aligning the extension path of the needle with the second blood vessel using the radiopaque marker and the radiopaque material, and extending the needle from the first blood vessel through the interstitial tissue between the first and second blood vessels and into the second blood vessel.

[0089] The method may further include extending a guidewire through a needle and into a second vessel, and entangled the guidewire in a second catheter. The entangled guidewire may include a closed expandable member. The method may further include moving the second catheter to move the guidewire through the second vessel. Aligning the needle's extension path with the second vessel may include rotating the first catheter in the first vessel such that a radiopaque marker changes between a first position and a second position. The first position may include a first thickness visible under fluorescence examination. The second position may include a second thickness visible under fluorescence examination. The first thickness may be different from the second thickness. The first catheter may include a needle opening on a first side. The radiopaque marker may be on a second side of the first catheter opposite to the first side. The first catheter may include a needle opening proximal to the radiopaque marker. The expandable member may include a balloon. Expanding the expandable member may include inflating a balloon using a radiopaque material.

[0090] In some embodiments, a method of accessing a subject's tibial vein includes positioning the subject in an inverted Trendbeg position, positioning a first tourniquet above the knee of the leg, positioning a second tourniquet above the ankle of the leg, injecting a certain amount of contrast agent through the metatarsal vein, flattening the subject after injecting the amount of contrast agent through the metatarsal vein, preparing for venography using fluorescence examination to image the veins of the foot of the leg, selecting the tibial vein using venography, advancing a guidewire to the selected tibial vein, removing the second tourniquet, tracing a functional catheter over the guidewire, capturing a second guidewire extending from the artery using the functional catheter, retracting the second guidewire from the foot, and tracing a second functional catheter over the second guidewire. The metatarsal vein may be a dorsal metatarsal vein of the foot. The metatarsal vein may be a plantar metatarsal vein. The functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a firing catheter). The second functional catheter may include a device for disabling a valve. The device for disabling a valve may include a valve knife. Devices that disable valves may include a cutting balloon. Devices that disable valves may include a rotary cutting device.

[0091] In some embodiments, a method of accessing a subject's tibial vein includes injecting a certain amount of contrast agent through a metatarsal vein, preparing for venography using fluorescence examination to image the veins of the foot of the leg, selecting the tibial vein using venography, advancing a guidewire to the selected tibial vein, tracing a functional catheter over the guidewire, extending a second guidewire from an artery into the tibial vein, capturing the second guidewire using the functional catheter, retracting the second guidewire from the foot, and tracing a second functional catheter over the second guidewire.

[0092] Metatarsal veins may be dorsal metatarsal veins of the foot. Functional catheters may include catheters for fistula formation (e.g., target catheters, firing catheters). Secondary functional catheters may include devices for decompressing valves. Devices for decompressing valves may include valvular knives. Devices for decompressing valves may include cutting balloons. Devices for decompressing valves may include rotary cutting devices.

[0093] In some implementations, a method of accessing a subject's tibial vein includes injecting a certain amount of contrast agent through a metatarsal vein, preparing for venography using fluorescence examination to image the veins of the foot of the leg, selecting the tibial vein using venography, advancing a guidewire to the selected tibial vein, and tracing a functional catheter over the guidewire.

[0094] The metatarsal vein may be a dorsal metatarsal vein of the foot. The metatarsal vein may be a plantar metatarsal vein. The functional catheter may include an element configured to capture a guidewire. The method may further include capturing a second guidewire extending from the artery using the functional catheter and retracting the second guidewire. The method may further include tracing the second functional catheter over the second guidewire. The functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a launching catheter). The second functional catheter may include a device for deactivating the valve. The device for deactivating the valve may include a valvular knife. The device for deactivating the valve may include a cutting balloon. The device for deactivating the valve may include a rotary cutting device.

[0095] In some embodiments, a cut-and-remove system comprises or substantially consists of a capture structure and a valve knife structure.

[0096] The system may further include an outer sheath. The capture structure and the valvular blade structure may be interchangeable within the outer sheath. The valvular blade structure may be proximal to the capture structure. The capture structure may be configured to extend distally from the outer sheath. The valvular blade structure may be integral with the capture structure. The outer sheath may include multiple orifices. The valvular blade structure may be configured to extend laterally from the outer sheath through the multiple orifices. The capture structure may include multiple units configured to receive a guidewire. The capture structure may include multiple struts configured to capture the guidewire. The capture structure may include multiple wires configured to capture the guidewire. The valvular blade structure may be proximal to the capture structure. The valvular blade structure may be distal to the capture structure. The valvular blade structure may be integral with the capture structure. The capture structure may have a first diameter, and the valvular blade structure may have a second diameter smaller than the first diameter. The capture structure may be configured to flip into a valvular blade structure after a longitudinal force is applied to the capture structure. The valvular blade structure may be separate from the capture structure. The valvular blade structure may be configured to extend and retract within the capture structure. The capture structure can be configured to extend and retract within the valvular knife structure. The valvular knife structure can include an expandable member configured to apply radially outward forces to the capture structure. The valvular knife structure can contain multiple blades. The number of blades can range from two to eight. The number of blades can include three blades. The number of blades can include four blades. The multiple blades can be proximal. The multiple blades can be distal. The multiple blades can be both proximal and distal.

[0097] In some embodiments, a cutter / eliminator system comprises or substantially consists of: a capture structure, a valve blade structure, and an outer sheath. The capture structure includes multiple units configured to receive a guidewire, and the valve blade structure is contained between two proximal-facing blades and eight proximal-facing blades. The capture structure and the valve blade structure are expandable from the outer sheath. The valve blade structure may be integral with the capture structure.

[0098] In some embodiments, a method of accessing a plantar vein of a subject includes positioning the subject in an inverted Trendbeg position, positioning a first tourniquet above the knee of the leg, positioning a second tourniquet above the ankle of the leg, injecting a certain amount of contrast agent through the metatarsal vein, flattening the subject after injecting the amount of contrast agent through the metatarsal vein, preparing for venography using fluorescence examination to image the veins of the foot of the leg, selecting the plantar vein using venography, advancing a guidewire to the selected plantar vein, removing the second tourniquet, tracing a functional catheter over the guidewire, capturing a second guidewire extending from an artery using the functional catheter, retracting the second guidewire from the foot, and tracing a second functional catheter over the second guidewire.

[0099] Metatarsal veins may be dorsal metatarsal veins of the foot. Functional catheters may include catheters for fistula formation (e.g., target catheters, firing catheters). Secondary functional catheters may include devices for decompressing valves. Devices for decompressing valves may include valvular knives. Devices for decompressing valves may include cutting balloons. Devices for decompressing valves may include rotary cutting devices.

[0100] In some embodiments, a method of accessing a plantar vein of a subject includes injecting a certain amount of contrast agent through a metatarsal vein, preparing for venography using fluorescence examination to image the veins of the foot of the leg, selecting the plantar vein using venography, advancing a guidewire to the selected plantar vein, tracing a functional catheter over the guidewire, extending a second guidewire from an artery into the plantar vein, capturing the second guidewire using the functional catheter, retracting the second guidewire from the foot, and tracing a second functional catheter over the second guidewire.

[0101] Metatarsal veins may be dorsal metatarsal veins of the foot. Functional catheters may include catheters for fistula formation (e.g., target catheters, firing catheters). Secondary functional catheters may include devices for decompressing valves. Devices for decompressing valves may include valvular knives. Devices for decompressing valves may include cutting balloons. Devices for decompressing valves may include rotary cutting devices.

[0102] In some implementations, a method of accessing a subject's plantar vein includes injecting a contrast agent through a metatarsal vein, preparing for venography using fluorescence examination to image the veins of the leg's foot, selecting the plantar vein using venography, advancing a guidewire to the selected plantar vein, and tracing a functional catheter over the guidewire.

[0103] The metatarsal vein may be a dorsal metatarsal vein of the foot. The metatarsal vein may be a plantar metatarsal vein. The functional catheter may include an element configured to capture a guidewire. The method may further include capturing a second guidewire extending from the artery using the functional catheter and retracting the second guidewire. The method may further include tracing the second functional catheter over the second guidewire. The functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a launching catheter). The second functional catheter may include a device for deactivating the valve. The device for deactivating the valve may include a valvular knife. The device for deactivating the valve may include a cutting balloon. The device for deactivating the valve may include a rotary cutting device.

[0104] In some embodiments, a method of accessing a plantar vein of a subject includes positioning the subject in an inverted Trendbeg position, positioning a first tourniquet above the knee of the leg, positioning a second tourniquet above the ankle of the leg, injecting a certain amount of contrast agent through the metatarsal vein, flattening the subject after injecting the amount of contrast agent through the metatarsal vein, preparing for venography using fluorescence examination to image the veins of the foot of the leg, selecting the plantar vein using venography, advancing a guidewire to the selected plantar vein, removing the second tourniquet, tracing a functional catheter over the guidewire, capturing a second guidewire extending from the vein using the functional catheter, retracting the second guidewire from the foot, and tracing a second functional catheter over the second guidewire.

[0105] Metatarsal veins can be dorsolateral metatarsal veins of the foot. Metatarsal veins can be plantar metatarsal veins of the foot. A functional catheter may contain a catheter for forming a fistula. A secondary functional catheter may contain a device for disabling the valve. A device for disabling the valve may contain a valvular knife.

[0106] In some embodiments, a method of accessing a subject's tibial vein includes positioning a first tourniquet above the knee of the leg, positioning a second tourniquet above the ankle of the leg, injecting a contrast agent through the metatarsal vein, preparing for venography using fluorescence examination to image the veins of the foot of the leg, selecting the tibial vein using venography, advancing a guidewire to the selected tibial vein, removing the second tourniquet, and tracing a functional catheter over the guidewire. The first tourniquet may be of a different type than the second tourniquet.

[0107] In some embodiments, a method of aligning a catheter includes positioning a first catheter in a first blood vessel and positioning a catheter in a second blood vessel. The first catheter comprises a radiopaque material. The catheter includes a flat, rectangular radiopaque marker. The method further includes rotating an imaging system until the first catheter and the catheter are in an imaging plane. Rotating the imaging system includes drawing a first center line over the first catheter, drawing a second center line over the catheter, maximizing the distance between the first and second center lines, and generating a signal of the first catheter and the catheter in the imaging plane. The method further includes rotating the catheter until the thickness of the flat, rectangular radiopaque marker is minimized. Rotating the catheter includes drawing a first line along a first long edge of the flat, rectangular radiopaque marker, drawing a second line along a second long edge of the flat, rectangular radiopaque marker opposite the first long edge, minimizing the distance between the first and second lines, and generating a signal with the thickness minimized. The method further includes extending a needle from the catheter in the second blood vessel into the imaging plane, exiting the second blood vessel and entering the first blood vessel.

[0108] In some embodiments, a method of aligning a catheter includes positioning a first catheter in a first blood vessel and positioning a catheter in a second blood vessel. The first catheter comprises a radiopaque material. The catheter includes radiopaque markers. The method further includes rotating an imaging system until the first catheter and the catheter are in an imaging plane, and rotating the catheter until the thickness of the radiopaque markers is at a minimum. Rotating the catheter includes generating a signal indicating that the thickness is at a minimum.

[0109] In some embodiments, a method of aligning a catheter includes positioning a catheter containing a radiopaque marker in a blood vessel and rotating the catheter until the thickness of the radiopaque marker is at a minimum. Rotating the catheter may include generating a signal indicating that the thickness is at its minimum.

[0110] In some embodiments, a method for aligning a first and a second blood vessel in an imaging plane includes positioning a first conduit in the first blood vessel and positioning a second conduit in the second blood vessel. The first conduit comprises a radiopaque material. The second conduit comprises radiopaque markers. The method further includes rotating an imaging system until the first and second conduits are in the imaging plane. Rotating the imaging system includes drawing a first centerline over the first conduit, drawing a second centerline over the second conduit, maximizing the distance between the first and second centerlines, and generating signals for the first and second conduits in the imaging plane.

[0111] In some embodiments, a method of aligning a catheter includes injecting a contrast agent into a first blood vessel, injecting a contrast agent into a second blood vessel, and rotating an imaging system until the first and second blood vessels are in an imaging plane. Rotating the imaging system includes drawing a first line along the first blood vessel, drawing a second line along the second blood vessel, maximizing the area between the first and second lines, and generating signals for the first and second blood vessels in the imaging plane. The method further includes positioning the catheter in the second blood vessel. The catheter includes a flat, rectangular radiopaque marker. The method further includes rotating the catheter until the thickness of the flat, rectangular radiopaque marker is minimized. Rotating the second catheter includes drawing a first line along a first long edge of the flat, rectangular radiopaque marker, drawing a second line along a second long edge of the flat, rectangular radiopaque marker opposite the first long edge, minimizing the distance between the first and second lines, and generating signals with minimal thickness. The method further includes extending a needle from the catheter in the second blood vessel into the imaging plane, exiting the second blood vessel and entering the first blood vessel.

[0112] In some embodiments, a method for aligning a catheter includes injecting a contrast agent into a first blood vessel, injecting a contrast agent into a second blood vessel, and rotating an imaging system until the first and second blood vessels are in an imaging plane. Rotating the imaging system includes drawing a first line along the first blood vessel, drawing a second line along the second blood vessel, maximizing the area or distance between the first and second lines, and generating signals of the first and second blood vessels in the imaging plane. The method further includes positioning the catheter in the second blood vessel.

[0113] In some embodiments, a method of aligning a first blood vessel and a second blood vessel in an imaging plane includes injecting a contrast agent into the first blood vessel, injecting a contrast agent into the second blood vessel, and rotating the imaging system until the first blood vessel and the second blood vessel are in the imaging plane.

[0114] In some embodiments, a method of aligning a catheter includes positioning a first catheter in a first blood vessel and positioning a catheter in a second blood vessel. The catheter includes a radiopaque marker. The method further includes rotating the catheter until the thickness of the radiopaque marker is at a minimum, and generating a signal indicating that the thickness is at a minimum.

[0115] In some embodiments, a method of aligning a catheter includes positioning a first catheter in a first blood vessel and positioning a catheter in a second blood vessel. The catheter includes a radiopaque marker. The method further includes rotating the catheter until the thickness of the radiopaque marker is less than a certain value, and generating a signal indicating a thickness less than the value. The value may be less than 3 mm. The value may be less than 1 mm. The value may be less than 10 μm.

[0116] In some implementations, a method for increasing blood perfusion to the distal extremities by means of retrograde flow through the venous system includes diverting blood from arteries to a first vein and establishing a blood flow loop between the first and second veins.

[0117] The distal limbs may include the foot. The distal limbs may include the hand. The distal limbs may include the toes. The distal limbs may include the fingers. The artery may be the posterior tibial artery. The first vein may be the medial plantar vein. The second vein may be the anterior tibial vein. The second vein may be the lateral plantar vein. The first vein may be on the first side of the dorsal venous arch of the foot, and the second vein may be on the second side of the dorsal venous arch of the foot.

[0118] Establishing a blood flow loop may include disabling valves in at least one of the first or second veins. Disabling valves in at least one of the first or second veins may include using a valvular knife. Disabling valves in at least one of the first or second veins may include using a balloon. Disabling valves in at least one of the first or second veins may include using a stent. The stent may inhibit perfusion into the branch vessels through the lateral wall.

[0119] This method may include establishing a second blood flow loop between a first or second vein and a third vein. The third vein may be a lateral plantar vein. Establishing the second blood flow loop may include disabling valves in the third vein. Disabling valves in the third vein may include using a valvular knife. Disabling valves in the third vein may include using a balloon. Disabling valves in the third vein may include using a stent. The stent may inhibit perfusion into branch vessels through the lateral wall. The second blood flow loop may be established during the same interventional procedure. The second blood flow loop may be established during a later interventional procedure.

[0120] The method may also include restricting outflow from the venous system. Restricting outflow from the venous system may include directing blood through bifurcation veins or lateral branches.

[0121] The method may further include embolizing a bifurcation vein or its lateral branches. Embolizing a bifurcation vein or its lateral branches may include using at least one of a coil, microsphere, liquid embolization, or laser.

[0122] The method may also include applying external pressure to increase blood pressure in the distal extremities by restricting venous outflow. Applying external pressure may include using at least one of a clamp, tourniquet, or bandage. The application of pressure may be continuous or intermittent.

[0123] The method may further include diverting blood from a second artery to at least one of a second, third, or fourth vein. Diverting blood from an artery to a first vein does not include re-entry into the artery. The method may further include forming a fistula between an artery in the distal limb and a vein in the distal limb.

[0124] The method may further include generating flow loops for multiple venous targets. The multiple venous targets may include at least one vein in a first level of the distal limb and at least one vein in a second level of the distal limb. The multiple venous targets may also include a vein between at least one vein in the first level of the distal limb and at least one vein in the second level of the distal limb. The multiple venous targets may include a perforator.

[0125] Establishing a blood flow circuit can increase the pressure within that circuit. Increased pressure within the blood flow circuit can increase the distality of blood perfusion to limbs, including the distal extremities.

[0126] In some embodiments, a method for increasing blood perfusion to the toes by retrograde flow through the venous system includes diverting blood from an artery to a first vein. Diverting blood from an artery to a first vein does not involve re-entry into the artery. The method also includes establishing a blood flow loop between a first vein and a second vein. The first vein is located on a first side of the dorsal venous arch of the foot, and the second vein is located on a second side of the dorsal venous arch of the foot. Establishing the blood flow loop includes disabling a valve in at least one of the first or second veins using at least one of a valvular knife, a balloon, or a stent. The method also includes restricting outflow from the venous system by directing blood through a bifurcation vein or lateral branch. The method also includes embolizing a bifurcation vein or lateral branch using at least one of a coil, a microsphere, a liquid embolization, or a laser. The method also includes applying external pressure using at least one of a clamp, a tourniquet, or a band to increase blood pressure in the distal extremities by restricting venous outflow.

[0127] In some embodiments, devices, systems, kits, etc., for increasing blood perfusion to the toes by means of retrograde flow through the venous system include or optionally consist of: a first prosthesis configured to divert blood from an artery to a first vein; at least one of a valve knife, balloon, or stent configured to disable a valve to create a blood flow loop between the first and second veins; a flow-diverting stent configured to restrict outflow from the venous system by directing blood through a bifurcation vein or lateral branch; at least one of a coil, microsphere, liquid embolizer, or laser configured to embolize a bifurcation vein or lateral branch; and at least one of a cuff, tourniquet, or wrap configured to apply external pressure to increase blood pressure in the foot by restricting venous outflow.

[0128] In some embodiments, this document describes apparatus, systems, toolsets, and methods for increasing blood perfusion to the toes by means of retrograde flow through the venous system.

[0129] In some embodiments, this document describes apparatus, systems, toolsets, and methods for increasing blood perfusion to distal extremities by means of retrograde flow through the venous system.

[0130] In some implementations, a method for increasing blood perfusion to the distal extremities by means of retrograde flow through the venous system includes establishing a blood flow loop between a first vein and a second vein.

[0131] In some embodiments, a device for diverting blood flow from a first blood vessel to a second blood vessel and maintaining blood flow in the first blood vessel includes, or optionally comprises substantially, a first segment and a second segment. The first segment is configured to be anchored in the first blood vessel. The first segment includes a window to allow blood to flow into the first segment, through the window, and distally within the first blood vessel. The second segment is configured to be anchored in the second blood vessel. The second segment is configured to allow blood to flow into the first segment, through the second segment, and into the second blood vessel.

[0132] The first segment may include a scaffold structure. At least a portion of the scaffold structure may be uncovered. The second segment may include a scaffold structure. At least one parameter of the scaffold structure may be different between the first and second segments. The parameter may include a unit pattern. The second segment may include a graft cover. The graft cover may be generally perpendicular to the longitudinal axis of the device. The graft cover may be at an angle to the longitudinal axis of the device. This angle may be between about 10° and about 70°. The first segment may include a graft cover. The graft cover of the first segment may include a V-shaped incision. The first segment may be deployed separately from the second segment. A window may be formed during the manufacturing process. The window may be formed in situ. The first segment may include a puncturable graft. The first segment may include a scaffold structure configured to facilitate puncture. The first segment may include flaps configured to open radially outward. The first segment may include multiple flaps configured to open radially outward. The first segment may include branches configured to be positioned in a branch of a first vascular tract. The first segment may include multiple slits configured to open when the first segment bends. The device may include a woven fabric with variable porosity along its length. A first segment may include a portion having a first porosity configured to allow blood perfusion through that portion. A second segment may include a portion having a second porosity configured to deflect blood through that portion. The first porosity may be less than 75%. The second porosity may be greater than 60%. The device may also include an occlusive implant. The occlusive implant may include a tether configured to be anchored in the second segment. The second segment may include a third segment configured to restrict fluid flow through the device. The third segment may include a diameter narrower than the second segment. The first segment may include a flange.

[0133] In some embodiments, a method of forming a window in a device to divert blood flow from a first blood vessel to a second blood vessel and maintain blood flow in the first blood vessel includes, or optionally comprises, the following steps: implanting the device into the first blood vessel, extending through interstitial tissue and into the second blood vessel, and inserting a guidewire into a bend in the device within the first blood vessel. The guidewire punctures the graft material to form an opening.

[0134] The method may also include tracking a dilator on a guidewire to widen the opening. The dilator may have a curved tip. Inserting the guidewire through the curve may include exiting a catheter having an angled, ramped surface. The catheter may also include a straight path. The method may also include tracking a balloon on the guidewire. The balloon may extend through the opening. The method may also include inflating the balloon. The inflated balloon may widen the opening. The method may also include anchoring the guidewire. Anchoring the guidewire may include inflating the anchoring balloon in a first vessel. Inserting the guidewire through the curve may include forming multiple openings. The method may also include positioning a radiopaque target in the first vessel outside the device and downstream of the device. The method may also include deploying a stent through the opening.

[0135] In some embodiments, an apparatus for diverting blood flow from a first vessel to a second vessel and maintaining blood flow in the first vessel includes, or optionally comprises, substantially the following: a first segment including a stent structure having a perforation configured to allow blood to flow into the first segment, through the perforation, and distally in the first vessel, and / or flow into the first segment, through the first segment, and distally in the first vessel; and a second segment configured to allow blood to flow from the first vessel into the second segment, through the second segment, and into the second vessel.

[0136] The proximal end of the first segment can be configured to be placed in a first vascular duct. The distal end of the first segment can be configured to be placed in a second vascular duct. The proximal end of the first segment can be configured to be placed in a first vascular duct. The distal end of the first segment can be configured to be placed in a first vascular duct. The proximal end of the second segment can be configured to be placed in a first vascular duct. The distal end of the second segment can be configured to be placed in a second vascular duct. The length of the first segment can be approximately the same as the length of the second segment. The length of the first segment can be different from the length of the second segment. The diameter of the first segment can be approximately the same as the diameter of the second segment. The diameter of the first segment can be different from the diameter of the second segment. The second segment can be tapered (constricted) from proximal to distal. The proximal segment of the first segment can have a crescent shape. The distal segment of the first segment can have a circular shape. The proximal end of the first segment can be configured to be anchored in the first vascular duct and can be tapered inward toward the distal end. The second segment can extend from the distal end of the first segment. The second segment may include a third segment configured to restrict fluid flow through the device. The third segment may include a narrower diameter than the second segment. The first segment may include a flange.

[0137] In some embodiments, the implant includes, or optionally comprises substantially, a first portion and a second portion, the first portion including an occlusive implant configured to occlude blood flow in a blood vessel, and the second portion being tethered to the first portion. The second portion includes an anchor configured to couple to a stent.

[0138] Occlusive implants may include at least one of an expandable mesh, a sponge, a plug, a coil, multiple coils, an embolic fluid, a hydrogel, a microsphere, or an implantable balloon. Anchoring elements may include wires configured to form a coil upon release from the catheter.

[0139] In some embodiments, a device for diverting blood flow from a first blood vessel to a second blood vessel and maintaining blood flow in the first blood vessel includes, or optionally comprises, essentially: a flare and an elongated section, the flare being anchored to the first blood vessel, and the elongated section extending from the flare. The elongated section is configured to be anchored in the second blood vessel.

[0140] The flare can be configured to extend minimally into the first vessel. The device may include multiple flares, each including a flare. The flares among the multiple flares may be symmetrical. The flares among the multiple flares may be asymmetrical. At least one of the multiple flares may be longer than the others. At least one flare may be configured downstream of the other flares in the first vessel. The flare may be covered. The flare may be uncovered. The elongated segment may include a third segment configured to restrict fluid flow through the device. The third segment may include a narrower diameter than the second segment.

[0141] In some embodiments, an apparatus for diverting flow from branch vessels to perfuse distal vessels includes, or optionally comprises, substantially a plurality of wires woven together to form a mesh structure. The mesh structure may have an expansion diameter between about 4 mm and about 8 mm. The mesh structure may have a porosity between about 60% and about 75%. The mesh structure may have a length between about 50 mm and about 150 mm. The expansion structure may have a weaving angle between about 120° and about 179°. The mesh structure may have compressibility between about 0.4 N / mm and about 1.1 N / mm.

[0142] The mesh structure can have a truncated conical shape. The mesh structure can be tapered from the first expansion diameter to the second expansion diameter. The second expansion diameter can be configured to be downstream of the first expansion diameter. The mesh structure can have a sustained outward force between about 0.25 N / mm and about 0.6 N / mm. Each of the plurality of wires can have a diameter between about 50 μm and about 100 μm. Each of the plurality of wires can include a shape memory material. The mesh structure can have a PPI between about 50 and about 150.

[0143] In some embodiments, a device for reducing turbulence in a blood vessel includes, or optionally comprises, essentially a first segment and a second segment, the first segment having a first diameter and configured to overlap with a stent graft capable of stretching the blood vessel, and the second segment being tapered from the first diameter to the second diameter. The device is configured to stretch the blood vessel in a tapered manner to provide laminar flow through the device.

[0144] The diameter can be between approximately 2 mm and approximately 10 mm. The second diameter can be between approximately 1 mm and approximately 8 mm. The second segment can have a length between approximately 5 mm and approximately 100 mm. The second segment can have a porosity between approximately 60% and approximately 75%. The device may also include a first radiopaque marker at the proximal end of the first segment. The device may also include a second radiopaque marker at the transition between the first and second segments.

[0145] In some embodiments, a device for restricting fluid flow through a means comprises, or optionally substantially comprises, a first segment, a second segment, a third segment, a fourth segment, and a fifth segment, wherein the first segment has a first diameter and is configured to be anchored in a first vein, the fifth segment has a second diameter and is configured to be anchored in a second vein, and the third segment has a third diameter smaller than the first and second diameters. The third diameter is configured to restrict fluid flow through the means. The second segment is tapered from the first diameter to the third diameter. The fourth segment is tapered from the third diameter to the second diameter.

[0146] The first segment can be configured to divert fluid flow from a first vessel to a second vessel. The first segment can be configured to allow fluid to continue flowing through the first vessel. The first segment may include a window. A first diameter may be smaller than a second diameter. The first diameter may be the same as the second diameter. The first segment may include a flange having a fourth diameter greater than the first diameter. The device may include a stent structure and a graft. At least a portion of the first segment may be without a graft. The graft may have a third diameter in a third segment. The stent structure may have a fourth diameter greater than the third diameter in the third segment. The graft in the third segment may be configured to flex inward in response to a change in pressure. The graft in the third segment may be configured to flex outward in response to a change in pressure. The first segment may be configured to anchor in the P3 segment of the popliteal artery. The first segment may be configured to anchor in the tibioperoneal trunk. The first diameter may be between about 5 mm and about 7 mm. The first diameter may be between about 4 mm and about 6 mm. The second diameter may be between about 5 mm and about 7 mm. The third diameter can be between approximately 2.5 mm and approximately 5 mm. At least one of the second or third segments can be configured to provide laminar flow in the fifth segment.

[0147] In some embodiments, a device for restricting fluid flow through the apparatus includes, or optionally comprises substantially, a first segment, a second segment, and a third segment, the first segment having a first diameter and configured to be anchored in a first vein, and the third segment having a second diameter and configured to be anchored in a second vein. The first diameter is configured to restrict fluid flow through the apparatus. The second segment is tapered from the first diameter to the second diameter.

[0148] The first segment can be configured to divert fluid flow from a first vein to a second vein. The first segment can be configured to allow fluid to continue flowing through the first vein. The first segment may include a window. The first segment may include a flange having a third diameter greater than a first diameter. The device may include a scaffold structure and a graft. At least a portion of the first segment may be without a graft. The graft may have a first diameter in the first segment. The scaffold structure may have a third diameter greater than the first diameter in the first segment. The graft in the first segment can be configured to flex inward in response to a change in pressure. The graft in the first segment can be configured to flex outward in response to a change in pressure. The first diameter may be between about 2.5 mm and about 5 mm. The second diameter may be between about 5 mm and about 7 mm.

[0149] A device for restricting fluid flow through a means comprises, or optionally substantially comprises, a first segment, a second segment, a third segment, and a fourth segment, wherein the first segment has a first diameter and is configured to be anchored in a first vein, the second segment extends transversely to the first segment, and the fourth segment has a second diameter and is configured to be anchored in a second vein. The second segment has a third diameter smaller than the first and second diameters. The third diameter is configured to restrict fluid flow through the means. The third segment is tapered from the third diameter to the second diameter.

[0150] The first segment can be configured to divert fluid flow from the first pulse to the second pulse. The first segment can also be configured to allow fluid to continue flowing through the first pulse.

[0151] In some embodiments, an implant for restricting fluid flow through a lumen includes, or optionally comprises substantially, a first segment, a second segment, and a third segment. The second segment has a first diameter configured to restrict fluid flow through the implant and, when the implant is positioned within the lumen, restricts fluid flow through the lumen. The first segment tapers from a second diameter configured to anchor the implant within the lumen to the first diameter. The second segment tapers from the first diameter to a third diameter configured to anchor the implant within the lumen.

[0152] The first diameter can be between approximately 2.5 mm and approximately 5 mm. The graft in the first segment can be configured to flex inward in response to changes in pressure. The graft in the first segment can be configured to flex outward in response to changes in pressure. The lumen can be a flow diversion device. The lumen can be a vein. The system can include an implant and a flow diversion device configured to divert fluid flow from a first vessel to a second vessel. The implant can be configured to be positioned within the flow diversion device. The implant can be configured to be positioned within the second vessel.

[0153] The methods summarized above and further detailed below describe certain actions taken by a practitioner; however, it should be understood that they may also include actions instructed by another party. Thus, actions such as “causing valve insufficiency in the first blood vessel” include “instructing valve insufficiency in the first blood vessel”.

[0154] For the purpose of summarizing the invention and its achievable advantages, some objectives and advantages are described herein. It is not necessary to achieve all of these objectives and advantages according to any specific implementation. In some embodiments, the invention may be embodied or implemented in a manner that allows for the achievement or optimization of one or more advantages without necessarily achieving other objectives or advantages.

[0155] All these embodiments are intended to be within the scope of the invention disclosed herein. Referring to the accompanying drawings, these and other embodiments will be apparent from the following detailed description, and the invention is not limited to any specific disclosed embodiment(s). Optional and / or preferred features described with reference to some embodiments may be combined with and incorporated into other embodiments. All references cited herein (including patents and patent applications) are incorporated herein by reference in their entirety. Attached Figure Description

[0156] These and other features, aspects, and advantages of this disclosure are described with reference to the accompanying drawings of certain embodiments, which are intended to illustrate certain embodiments and are not intended to limit the invention, wherein the same reference numerals are used for the same features, and wherein:

[0157] Figure 1 An example embodiment of a transmitting device for a target device is schematically illustrated, which guides a signal from a first body cavity to a second body cavity.

[0158] Figure 2 It is along Figure 1 The cross-section of the dashed line BB is represented.

[0159] Figure 3 An example implementation of the launching device is illustrated schematically.

[0160] Figure 4An example implementation of the target device is illustrated schematically.

[0161] Figure 5 Another example implementation of the launching device is illustrated schematically.

[0162] Figure 6 An example embodiment of a centering device and / or target device for launch is schematically illustrated.

[0163] Figure 7 The illustration schematically depicts a prosthesis in its proper position following procedures such as arteriovenous arterialization.

[0164] Figure 8 This is a side perspective view of an example embodiment of a device for providing fluid flow.

[0165] Figure 9 This illustrates a branch used as a shunt between two blood vessels. Figure 8 The device.

[0166] Figure 10 This is a side perspective view of another example embodiment of a device for providing fluid flow.

[0167] Figure 11 This is a side perspective view of yet another example embodiment of a device for providing fluid flow.

[0168] Figure 12 This is a side perspective view of yet another example embodiment of a device for providing fluid flow.

[0169] Figure 13 This is a side perspective view of yet another example embodiment of a device for providing fluid flow.

[0170] Figure 14A This is a schematic side cross-sectional view of an example embodiment of an ultrasonic transmitting catheter.

[0171] Figure 14B It is inside circle 14B Figure 14A Enlarged schematic side cross-sectional view of the distal portion of the ultrasonic emission catheter.

[0172] Figure 15A This is a schematic side view of an example implementation of an ultrasound-guided target catheter.

[0173] Figure 15B It is within circle 15B Figure 15A A magnified schematic side cross-sectional view of the ultrasound target catheter.

[0174] Figure 15C It is within 15C of the circle Figure 15A A magnified schematic side cross-sectional view of the ultrasound target catheter.

[0175] Figure 16 This is an example implementation of a diagram for detecting catheter alignment.

[0176] Figure 17 This is a schematic side view of an example implementation of a prosthesis delivery system.

[0177] Figure 18 This is a schematic side view of an example implementation of the prosthesis.

[0178] Figure 19 This is a schematic side view of another example implementation of the prosthesis.

[0179] Figures 20A to 20H An example implementation of the method for achieving retrograde perfusion is illustrated schematically.

[0180] Figure 21 This is a schematic perspective view of an example embodiment of an ultrasonic receiving transducer.

[0181] Figure 22 This is a schematic cross-sectional view of another example embodiment of an ultrasonic receiving transducer.

[0182] Figure 23A This is a schematic perspective view of an example implementation of a valvulotome.

[0183] Figure 23B This is a schematic perspective view of an example implementation of a reverse valve knife.

[0184] Figure 24 This is a schematic perspective view of an example implementation of the LeMaitre device.

[0185] Figure 25A This is a schematic side view of yet another example implementation of the prosthesis.

[0186] Figure 25B This is a schematic side view of yet another example implementation of the prosthesis.

[0187] Figure 25C This is a schematic side view of yet another example implementation of the prosthesis.

[0188] Figure 26A and Figure 26B Another example implementation of the method for achieving retrograde perfusion is illustrated schematically.

[0189] Figure 27 Another example implementation of the prosthesis and method for achieving retrograde perfusion is illustrated schematically.

[0190] Figure 28A and Figure 28B The arteries and veins of the foot are illustrated schematically.

[0191] Figure 29 An example embodiment of the anastomosis device is illustrated schematically.

[0192] Figure 30 An example implementation of a device that couples two blood vessels together is illustrated schematically.

[0193] Figure 31A An example embodiment of an arteriovenous fistula stent (fistulastent) separate from an example embodiment of a venous stent is schematically illustrated.

[0194] Figure 31B An example embodiment of an arteriovenous fistula stent comprising an integrated venous stent is schematically illustrated.

[0195] Figure 31C An example embodiment of a fistula stent comprising an integrated venous stent is schematically illustrated.

[0196] Figures 32A to 32D An example method and apparatus for identifying and avoiding bifurcation 1104 in a percutaneous bypass procedure are illustrated.

[0197] Figure 33A and Figure 33B An example procedure is schematically illustrated that can be executed after the connection of the first and second vessels when the needle traverses the interstitial tissue.

[0198] Figures 34A to 35F The illustration shows an example procedure that can be executed when the guidewire is in a blood vessel.

[0199] Figures 36A to 36D The illustration shows an example method to promote retrograde perfusion of blood through veins into the toes.

[0200] Figure 37A The illustration shows an example of a device that disables a valve when it is in a radially expanded state.

[0201] Figure 37B yes Figure 37A An unfolded side view of a device that disables valves.

[0202] Figure 37C Through Figure 37B In the area marked by circle 37C Figure 37A An enlarged view of the unfolded side view of the device that disables the valve.

[0203] Figure 37D Is it as in Figure 37B As shown in the figure Figure 37A An end view of a device that disables valves.

[0204] Figure 37EIt is in a state of radial contraction. Figure 37A An end view of a device that disables valves.

[0205] Figure 37F It is in a state of radial contraction. Figure 37A A side view of a device that disables valves.

[0206] Figure 37G It is in a radially contracting state and is related to Figure 37F Compared to being rotated circumferentially Figure 37A Another side view of the device that disables the valve.

[0207] Figure 37H It is in a radially expanding state. Figure 37A A side view of a device that disables valves.

[0208] Figure 37I It is in a radially expanding state and is related to Figure 37H Compared to being rotated circumferentially Figure 37A Another side view of the device that disables the valve.

[0209] Figure 37J It is along Figure 37H The line 37J-37J obtained is in a radially expanding state. Figure 37A A cross-sectional end view of a device that disables valves.

[0210] Figures 37Ki to 37Nii The diagram shows the usable... Figure 37A Example program executed by a device that disables valves.

[0211] Figure 38A An example of the distal end of the catheter is illustrated schematically.

[0212] Figures 38B to 38D The diagram shows the usable... Figure 38A Example program executed at the distal end of the catheter.

[0213] Figure 38Ei and Figure 38Eii An example of the distal end of a catheter is illustrated.

[0214] Figure 38F The illustration shows an example of a portion of a catheter.

[0215] Figure 38G Another example of a portion of a catheter is illustrated.

[0216] Figure 39A This is a perspective view of an example of a target catheter.

[0217] Figure 39B It is in the first state. Figure 39ASide view of the target catheter.

[0218] Figure 39C It is in the second state. Figure 39A Side view of the target catheter.

[0219] Figures 39D to 39I The illustration shows the use Figure 39A Example methods for targeting catheters.

[0220] Figure 40A This is a perspective view of an example handle used to deploy a tubular structure.

[0221] Figure 40B yes Figure 40A An expanded perspective section view of a portion of the handle.

[0222] Figure 40C It is in the deployment state. Figure 40A A perspective view of the handle.

[0223] Figure 40D It is in the deployment state. Figure 40A An expanded perspective section view of a portion of the handle.

[0224] Figure 41A This is a perspective view of an example handle used to deploy a tubular structure.

[0225] Figure 41B yes Figure 41A A partial perspective view of the expanded handle portion.

[0226] Figures 41C to 41Eii i shows the operation Figure 41A Example methods for handles.

[0227] Figure 42A This is a top view of an example implementation of the launching device.

[0228] Figure 42B yes Figure 42A Schematic top view, side view and far-end perspective view of the far part of the transmitting device.

[0229] Figure 42Bi This is a schematic side view of an example of a non-transparent marker.

[0230] Figure 42C yes Figure 42A A schematic, expanded top view of the distal portion of the launching device.

[0231] Figure 42Ci-Figure 42Ciii The illustration shows an example catheter including a shaped piece attached to a needle.

[0232] Figure 42D yes Figure 42AA schematic side view of the distal portion of the transmitting device.

[0233] Figures 43A-43N The illustration schematically shows the use of including Figure 42A An example method for the transmitter of the transmitter device on the far side of the transmitter device.

[0234] Figure 43Oi-Figure 43Ovi An example implementation of alignment using software is illustrated.

[0235] Figures 44A-44J The anatomy of an example foot is illustrated schematically.

[0236] Figure 45 Example components of a tool kit that can be used for foot entry are shown.

[0237] Figures 46A-46K An example procedure for performing ascending venography is shown.

[0238] Figure 47A This is a perspective view of a portion of an example cut-out exterminator system.

[0239] Figure 47Bi and Figure 47 Bii This is a side view of another example cut-out system.

[0240] Figures 47Ci-47Ciii This is a side view of another example cut-out system.

[0241] Figure 47 Civ This is a side view of yet another example of a cut-out exterminator system.

[0242] Figure 47Di-Figure 47Dv This is a side view of yet another example of a cut-out exterminator system.

[0243] Figures 47Ei-47Eiii This is a side view of yet another example of a cut-out exterminator system.

[0244] Figure 47 Eiv This is a side view of another example cut-out system.

[0245] Figure 47Fi and Figure 47Fii This is a side view of yet another example of a cut-out exterminator system.

[0246] Figure 47Gi-Figure 47Giii This is a side view of yet another example of a cut-out exterminator system.

[0247] Figure 48A The illustration shows an example image of the foot after a venous arterialization procedure.

[0248] Figure 48B Another example image of the foot following a venous arterialization procedure is shown.

[0249] Figure 49 The illustration shows an example method of supplying blood flow to multiple veins.

[0250] Figure 50 The illustration shows a method of using an embolization coil to prevent vascular steal and redirect blood to the distal side.

[0251] Figure 51A It is a partial cross-section of an example device that provides fluid flow from the first vein to the second vein and through the first vein.

[0252] Figure 51B This is a side view of another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0253] Figure 51C This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0254] Figure 51D This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0255] Figure 52A This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0256] Figure 52Bi This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0257] Figure 52 Bii yes Figure 52Bi Example cross-sectional view of the device along line 52Bx-52Bx.

[0258] Figure 52Biii yes Figure 52Bi Another example cross-sectional view of the device along line 52Bx-52Bx

[0259] Figure 52Ci This is a side view of another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0260] Figure 52Cii yes Figure 52Ci The device is shown in cross-sectional view along line 52Cii-52Cii.

[0261] Figure 52D This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0262] Figure 53AThis is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0263] Figure 53Bi-53Biii The illustration shows an example method for in-situ formation of an example apparatus that provides fluid flow from a first vascular bundle to a second vascular bundle and through the first vascular bundle.

[0264] Figure 53Ci An example unit pattern for a bracket structure used in windowed installations is shown.

[0265] Figure 53Cii It shows partial coverage of the graft and includes a window. Figure 53Ci An example of a support structure.

[0266] Figure 53Di The illustration shows an example method for in-situ formation of an example apparatus that provides fluid flow from a first vascular bundle to a second vascular bundle and through the first vascular bundle.

[0267] Figure 53Dii It shows that it can be used with Figure 53Di An example of the device used together is a conical segment.

[0268] Figure 53Diii It shows that it can be used with Figure 53Di Another example of the device used together is a conical segment.

[0269] Figure 53Ei and 53Eii The illustration shows an example method of an example apparatus for aligning a puncture device to create in situ fluid flow from a first vessel to a second vessel and through the first vessel.

[0270] Figure 54A This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0271] Figure 54Bi This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0272] Figure 54 Bii This is a side view of another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0273] Figure 54C This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0274] Figure 55A This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0275] Figure 55B This illustrates a vessel positioned within the first blood vessel, extending through the interstitial tissue, and entering the second blood vessel. Figure 55A The device.

[0276] Figure 55C Another example apparatus is shown that provides fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0277] Figure 55D It is implanted in the first and second blood vessels. Figure 55C The device's remote view.

[0278] Figure 55Ei It is sharing Figure 55C and 55D A top view of the device's features.

[0279] Figure 55Eii It is sharing Figure 55C and 55D A top view of another device that features the characteristics of the device.

[0280] Figure 55F Another example apparatus is shown that provides fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0281] Figure 55G yes Figure 55F A top view of the device.

[0282] Figure 56A This is a side view of yet another example device providing fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0283] Figure 56B This shows the porosity values ​​for different devices with and without porosity. Figure 56A A graph showing the flow rate through the maternal blood vessels and lateral branches in the case of the device.

[0284] Figure 57A An example device for guiding flow below the ankle is illustrated.

[0285] Figure 57Bi The illustration shows a first example of blood flow through a vein near the ankle.

[0286] Figure 57Bii The illustration shows a second example of blood flow through a vein near the ankle.

[0287] Figure 57Ci-57Ciii The diagram illustrates the relationship between... Figure 57A Example variants of weaving flow steering devices that share features with the device.

[0288] Figure 57Di The illustration shows a device in which a portion of the graft covering is perforated with multiple openings.

[0289] Figure 57 Dii yes Figure 57Di A schematic side view of the device, showing the effect of the porous region on fluid flow.

[0290] Figure 57E This is a porosity spectrum showing the effect of porosity on blood theft.

[0291] Figure 57Fi This is a side view of another example device configured to provide fluid flow from the first vascular bundle to the second vascular bundle and through the first vascular bundle.

[0292] Figure 57Fii This is an enlarged view of the device in region 57Fii.

[0293] Figure 57Fiii A device is shown that is positioned in a first blood vessel, extends through interstitial tissue, and enters a second blood vessel.

[0294] Figure 57Fiv This is an enlarged view of the 57Fiii apparatus in region 57Fiv.

[0295] Figure 58A This is a side view of an example occluded implant.

[0296] Figure 58Bi-58Biii The diagram shows... Figure 58A An example method for in-situ coupling of an occlusive implant and an example device for providing fluid flow from a first vascular duct to a second vascular duct and through the first vascular duct.

[0297] Figure 58C It includes Figure 58A A side view of an example occlusion implant system.

[0298] Figure 59Ai The illustration shows a third example of blood flow through a vein near the ankle.

[0299] Figure 59Aii The illustration shows a fourth example of blood flow through a vein near the ankle.

[0300] Figure 59B The illustration shows the overlap with the scaffold graft. Figure 59Aii The device.

[0301] Figure 60 It is a partially transparent view showing certain vascular systems of the lower left leg.

[0302] Figure 61A The illustration shows an example of a prosthesis that can be placed upstream of the occlusion.

[0303] Figure 61BThe illustration shows another example of a prosthesis that can be placed upstream of the occlusion.

[0304] Figure 61C The illustration shows yet another example of a prosthesis that can be placed upstream of the occlusion.

[0305] Figure 61D The illustration shows yet another example of a prosthesis that can be placed upstream of the occlusion.

[0306] Figure 62A The illustration shows an example of a prosthesis that can be placed upstream of the occlusion.

[0307] Figure 62B The illustration shows another example of a prosthesis that can be placed upstream of the occlusion.

[0308] Figure 62C The illustration shows yet another example of a prosthesis that can be placed upstream of the occlusion.

[0309] Figure 62D The illustration shows yet another example of a prosthesis that can be placed upstream of the occlusion.

[0310] Figure 63A The illustration shows an example of a prosthesis that can be placed upstream of the occlusion.

[0311] Figure 63B The illustration shows another example of a prosthesis that can be placed upstream of the occlusion.

[0312] Figure 63C The illustration shows yet another example of a prosthesis that can be placed upstream of the occlusion.

[0313] Figure 64 An example of a mobility-restricting implant is illustrated.

[0314] Figure 65 The illustration shows yet another example of a prosthesis that can be placed upstream of the occlusion. Detailed Implementation

[0315] While certain implementations and examples are described below, the invention extends beyond the specific disclosed implementations and / or applications, as well as their obvious modifications and equivalents. The scope of the invention disclosed herein should not be limited by any (one or more) specific implementations described below.

[0316] Minimally invasive surgery can provide a means of treating a wider range of patients, including those currently excluded from standard surgical techniques. One such procedure is percutaneous in situ coronary artery arterialization (PICVA), a catheter-based coronary artery bypass procedure in which a blockage in a diseased artery is “bypassed” by establishing a pathway between a coronary artery and an adjacent coronary vein. In this way, arterial blood is diverted into the venous system and can be perfused retrogradely (retrograde perfusion) into the heart tissue and blood supply to ischemic tissue is restored. Some example apparatuses and methods for performing procedures such as PICVA are described in PCT Publication WO99 / 049793 and U.S. Patent Publication 2004 / 0133225, which are incorporated herein by reference in their entirety.

[0317] Successful execution of minimally invasive procedures to divert blood flow from the coronary arteries to adjacent veins has historically had a low success rate, often due to the inability to properly target the vein from the artery. Without suitable systems and methods, such procedures (e.g., attempts to target veins using a combination of X-ray fluorescence examination and an imaging ultrasound probe located at the distal tip of the catheter, as described in U.S. Patent Publication No. 2004 / 0133225) are often doomed to failure even before they begin. In fact, such arrangements can be difficult to navigate, and locating adjacent veins can require considerable skill from the clinician. Generally, improvements to the systems and methods used for targeting (such as those using the catheters described herein) have often enabled procedures such as PICVA and transvascular surgeries. Without such improvements, these percutaneous techniques remain secondary for conventional open-heart surgery and other types of bypass surgery.

[0318] According to several embodiments, this application describes methods and systems that can be used in minimally invasive surgical procedures to treat conditions such as coronary artery disease and severe limb ischemia, reducing the performance of conventional surgery. For example, it can treat patients who may otherwise be unable to undergo surgeries such as coronary artery bypass surgery or peripheral artery bypass surgery, and the amount of surgical trauma, risk of infection, and / or recovery time can be reduced or significantly reduced compared to conventional surgery.

[0319] Figure 1An example embodiment of a transmitting device 10 that directs a signal from a first body cavity 30 to a target device 20 in a second body cavity 35 is schematically illustrated. The transmitting device 10 includes a signal transmitter 12. The transmitting device 10 may include, for example, a catheter comprising an elongated, flexible rod-like portion and an end portion, and may provide a conduit for administering treatment within a patient's body. The transmitting device 10 may be adapted to be positioned and moved through a first body cavity or blood vessel 30 (e.g., a ventricle, coronary artery, coronary vein, peripheral artery, peripheral vein) within the patient's body. The elongated segment of the transmitting device 10 includes an outer sheath 11 that surrounds a space defining an inner lumen 13. The space within the inner lumen 13 may be appropriately divided or subdivided as needed to define pathways for administering treatment, controlling the positioning of the transmitting device 10, etc. For example, such subdivision may be implemented longitudinally or concentrically in an axial manner.

[0320] The transmitting device 10 includes a signal transducer 12. The signal transducer 12 is configured to provide or emit a signal 40 directed outward from the transmitting device 10. Figure 1 In the embodiment shown, signal 40 is guided radially outward from transmitter 10 in a direction perpendicular to the longitudinal axis of transmitter 10. As will be discussed in more detail below, in some embodiments, the direction of signal 40 does not need to be perpendicular to the longitudinal axis of transmitter 10 and may be guided at an angle to the longitudinal axis of transmitter 10. Signal transducer 12 may thus form at least part of a signal generating device.

[0321] The signal transducer 12 is connected to the signal transmitter 50. The signal transmitter 50 may be suitably selected from an ultrasound source or a suitable electromagnetic source, such as laser, microwave radiation, radio waves, etc. In some embodiments, as described in further detail below, the signal transmitter 50 is configured to generate an ultrasound signal, which is forwarded to the signal transducer 12, which in turn directs the signal 40 out of the first body cavity 30 into the surrounding tissue.

[0322] The target device 20 is located within an adjacent second body cavity or vessel 32 (e.g., a ventricle, coronary artery, coronary vein, peripheral artery, or peripheral vein) within the patient's body. The first body cavity 30 and the second body cavity 32 are separated by interstitial tissue 34, sometimes referred to as interstitial tissue or a septum. The first body cavity 30 and the second body cavity 32 are positioned close to each other in a parallel manner for at least a portion of their respective lengths. For example, many veins and arteries of the body are known to extend parallel to each other for at least a portion of their total length.

[0323] The target device 20 may be arranged similarly to that of the launching device 10. For example, the target device 20 may include a conduit comprising an elongated, flexible rod-like portion and an end portion. In another example, fine movement and positioning of the target device 20 within the body cavity 32 can be achieved. In yet another example, the target device 20 may include an outer sheath 21 surrounding a space, defining an inner cavity 23. The inner cavity 23 may be appropriately divided, for example, as in the case of the launching device 10.

[0324] The target device 20 includes a receiving transducer 22 configured to receive a signal 40 from the transducer 12 of the transmitting device 10. The receiving transducer 22 forms at least a part of a signal detection device. In use, when the receiving transducer 22 receives the signal 40 transmitted from the signal transducer 12, the receiving transducer 22 transmits the received signal to a signal detector 60. The signal detector 60 is configured to provide an output reading to the user of the system, for example, via an output display 61. The output display 61 may be a visual display, an audio display (e.g., beeping or emitting some other sound upon receiving a signal), etc.

[0325] In this way, the transmission and detection of the guided signal 40 allows the transmitting device 10 to navigate and position relative to the target device 20. In use, the transmitting device 10 and the target device 20 can be manipulated by the system user until the output display 61 indicates that the signal 40 is being received by the target device 40.

[0326] In some embodiments, signal 40 includes an ultrasound signal or an ultrasonic signal. Signal 40 is directional and emitted through signal transducer 12 in the shape of a narrow cone or arc (e.g., the width of the signal band increases with increasing distance from signal transducer 12). Therefore, the alignment accuracy between transmitting device 10 and target device 20 depends not only on signal detection but also on the distance between the two devices—because the signal beam width is greater at greater distances. This level of error is called “positional uncertainty.” There may be a certain level of tolerance for positional uncertainty; however, if precise guidance for treatment is to be provided, the amount of uncertainty should be reduced or minimized. For example, if the diameter d of signal transducer 12 is 1 mm and the frequency of the ultrasound signal is 30 MHz, then the positional uncertainty x (e.g., the error margin on either side of the centerline) is 1 mm at a 5 mm vertical distance between transmitting device 10 and target device 20. For clinical applications, the positional uncertainty (for a total signal beam width of 10 mm at the receiving point) should generally not exceed approximately ±5 mm. In some embodiments, the positional uncertainty is between about ±0.01 mm and about ±4.50 mm, or between about ±0.1 mm and about ±2 mm. In some embodiments, the positional uncertainty does not exceed about ±1 mm.

[0327] The intensity of signal 40 can be a factor in detection, and the signal intensity generally decreases as the distance between the transmitting device 10 and the target device 20 increases. This distance is determined in part by the amount of intercalary tissue 34 between devices 10 and 20. For example, if signal 40 is an ultrasound signal, a significant signal attenuation can be expected when the transmitting device 10 and the target device 20 are separated by more than about 20 mm of solid tissue (e.g., intercalary tissue 34). The density of the intercalary tissue 34 relative to the distance can also affect the attenuation of signal 40 (e.g., denser tissue causes more signal attenuation compared to less dense tissue).

[0328] The frequency of the ultrasonic signal can also affect the thickness of the signal transducer. For a standard ultrasonic ceramic transducer (e.g., a piezoelectric transducer (PZT)), the thickness of the signal transducer is 0.075 mm at 30 MHz.

[0329] Figure 2 It is along Figure 1 The cross-section is represented by the dashed line B–B. The correct orientation of the transmitting device relative to the target device can be a factor in detection, as the orientation line 41 determines where treatment will be applied. If the pointing signal 40 is associated with the device used to deliver treatment (e.g., offset parallel and longitudinally), it can better fulfill the clinical need for precise placement of treatment in the patient. For example, in this way, the user of the system can apply treatment to the correct location by ensuring that the transmitting device 10 and the target device 20 are correctly positioned via the transmission and reception of signal 40. Figure 2 The orientation line 41 in the diagram not only indicates the direction of the signal's travel but also the path along which the treatment can be applied to the patient.

[0330] Figure 3 An example embodiment of the transmitting device 10 is schematically illustrated. The transmitting device 10 includes a signal transducer 120 oriented at an oblique angle relative to the longitudinal axis of the transmitting device 10. When the transmitting device enters the body cavity 30 ( Figure 1 and 2 Signal 40 is transmitted at an angle along the direction of travel of the transmitting device 10 (e.g., forward travel, lateral travel). In some embodiments, the beam angle is approximately perpendicular to the longitudinal axis of the transmitting device 10. In some embodiments, when 0° corresponds to the longitudinal axis of the transmitting device 10 in the direction of travel, the beam angle is between approximately 20° and approximately 60° with respect to the vertical, between approximately 30° and approximately 50° with respect to the vertical, or approximately 45° with respect to the vertical.

[0331] The dispensing device 10 includes a hollow needle or cannula 17, which is an example device for administering treatment. During the travel of the dispensing device 10, the hollow needle 17 is located within the lumen 13 of the dispensing device 10 in an undeployed or retracted state. The hollow needle 17 can be deployed / extended from the dispensing device 10 via an orifice 16 in the outer sheath 11 at a time deemed appropriate by the user (e.g., after signal 40 is detected by target device 20). The orifice 16 allows fluid communication between the lumen 13 and the body cavity 30. Figure 1 ).like Figure 3 As illustrated in the example embodiment, the hollow needle 17 can travel along a path parallel to the direction of the signal 40. The hollow needle 17 can be used to puncture the intercalary tissue 34 ( Figure 1 In some embodiments, the hollow needle 17 makes passage through the entire intercalary tissue 34, and doing so allows the firing device 10 to enter the second body cavity 32. Figure 2 If necessary, the path through the intercalary tissue 34 created by the hollow needle 17 can then be widened to allow fluid communication between the first body cavity 30 and the second body cavity 32.

[0332] Treatment devices suitable for use in several embodiments may include, for example, devices and / or instruments selected from the group consisting of: cannulas, lasers, radiation emitting devices, probes, drills, blades, wires, needles, suitable combinations thereof, etc.

[0333] In some embodiments, the hollow needle 17 includes a sensor 19, which can help further determine the positional information of the tip of the hollow needle 17 relative to the launching device 10. In some embodiments, the sensor 19 is configured to detect changes in hydrostatic pressure. Other sensors suitable for use in the systems and methods described herein may include temperature sensors, oxygenation sensors, and / or color sensors.

[0334] Optionally, the hollow needle 17 may include an additional signal transducer 122. Figure 3 In the embodiment shown, the signal transducer 122 is located near the end of the hollow needle 17 on the end of the guide wire 14. If desired, the signal transducer 122 may also or optionally be located on the hollow needle 17. In use, the signal transducer 122 is driven by short transmit pulses that generate directional and non-directional signal pulses. The signal pulses can be detected by a receive transducer 22 mounted on the target device 20. The distance from the guide wire 14 or hollow needle 17 to the receive transducer 22 and thus to the target device 20 can be determined at least in part by the time delay between the transmission of the signal pulse from the signal transducer 122 and the reception of the signal pulse on the receive transducer 22.

[0335] Figure 4An example embodiment of the target device 20 is schematically illustrated. Figure 4 In the embodiment shown, the target device 20 is located within a body cavity 32. As mentioned above, the target device 20 includes a receiving transducer 22 for receiving a signal 40. The receiving transducer 22 can be unidirectional (e.g., capable of receiving signals only from one direction) or omnidirectional (e.g., capable of receiving signals from any direction). Arrow A indicates the reverse direction of blood flow after arteriovenous arterialization (also known as PICVA) has been achieved. The target device 20 includes an omnidirectional ultrasound signal receiving transducer 60. An optional reflective cone 601 can direct the signal 40 onto the disc-shaped receiving transducer 60. An acoustic window 602 can separate the reflective cone 601 from the receiving transducer 60. In some embodiments, the omnidirectional ultrasound signal receiving transducer can be obtained by positioning a cylinder of a flexible piezoelectric material, such as polyvinylidene fluoride (PVDF), around the outer sheath of the target device 20. In this way, the cylinder can function in a similar or equivalent manner to the receiving transducer 60.

[0336] exist Figure 4 In the embodiment illustrated in the figure, the target device 20 includes an optional passage 25 for administering a drug, such as a therapeutic agent, to a patient. In some embodiments, the passage 25 functions as a conduit to allow the application of an occlusive material 251 for at least partially obstructing or occluding a body cavity 32. The occlusive material 251 may suitably be selected from gel-based substances. The occlusive material 251 may also or optionally include an embolization member (e.g., a balloon, a self-expanding stent, etc.). Placement of the occlusive material 251 can be guided by moving the target device 20. A guiding member 24 is present within the lumen 23 of the target device 20 to allow the user to precisely manipulate the position of the target device 20 as needed.

[0337] Refer again Figure 2 The transmitting device 10 includes a signal transducer 12 that can be optionally oriented so that the signal 40 is transmitted at an angle not perpendicular to the signal transducer 12. Figure 5 Another example embodiment of the launching device 10 is schematically illustrated. In some embodiments, for example in Figure 5 The transmitting device 10 shown has a signal transducer in the form of a signal transducer array 123. The signal transducer array 123 includes a plurality of signal transducer elements 124, which may be oriented together to at least partially define the signal beam width and the angle relative to the transmitting device 10. The small size of the elements 124 allows the signal transducer 123 to not occupy a significant proportion of the cavity 13 of the transmitting device 10.

[0338] Figure 5 The embodiments shown can be used to generate ultrasonic beams signals. Figure 5An array of signal transducer elements 124, each connected to a transmitter 50 via a delay element 51, is shown. The delay element 51 allows the signal to each element 124 to be delayed relative to each other. The delay element can provide or ensure that the ultrasonic wave fronts from each element 124 are aligned to generate an ultrasonic beam 40 at a desired angle. For example, in some embodiments where the signal 40 includes visible light, an array of LEDs may also be used or optionally.

[0339] Figure 6 The illustration schematically depicts example embodiments of a centering device and / or target device 10, 20 for launch. To aid in the alignment process between the launch device 10 in the first cavity 30 and the target device 20 in the second cavity 32, one or both of the devices 10, 20 may include means for centering the respective device within their cavities.

[0340] In some embodiments, the centering device includes an inflatable sac or balloon 111, which is located within the lumens 13, 23 in an undeployed state and can inflate when the devices 10, 20 reach the desired position within the patient. The balloon 111 may be disposed on the outer surface of the outer sheaths 11, 21. The balloon 111 is annular in shape, such that it at least partially surrounds the devices 10, 20 in a toroidal or doughnut-like manner. The balloon 111 may be arranged such that it inflates on only one side or only two opposing sides of the devices 10, 20. Figure 6 As shown in the figure, the balloon 111 is deployed on one side of the launching device 10.

[0341] In some embodiments, the centering device includes one or more ring structures 112 in an undeployed or retracted state located within recesses manufactured in the cavities 13, 23 or the outer sheaths 11, 21. When the devices 10, 20 reach the desired position within the patient, one or more ring structures 112 can expand radially outward from the devices 10, 20, thereby centering the devices 10, 20 within the body cavities 30, 32. The outward expansion of the ring structures 112 can be suitably achieved by compressing a length of filament, for example, by bending it outward from the outer sheaths 11, 21 into an arc shape. A centering device employing this configuration may include a plurality of compressible lengths of filament or other suitable flexible material arranged radially spaced parallel to the periphery of the outer sheaths 11, 21. Compression of the plurality of filaments can be caused via sliding members (not shown) positioned proximally and / or distally near the ends of the plurality of filaments. The sliding members are translatably movable along the longitudinal axis of the devices 10, 20. Figure 6 As illustrated, the target device 20 includes a fully deployed centering device 112, which allows the target device 20 to be centered within the body cavity 32.

[0342] Other possible devices for centered placement of devices 10 and 20 within body cavities 30 and 32 include, but are not limited to, expandable Chinese lantern-shaped devices, reversibly expandable supports, coils, helices, retractable probes or legs, combinations thereof, and the like.

[0343] In some embodiments, a centering device or other device (e.g., a balloon, a metal stand-off of different lengths, etc.) may be used to orient devices 10, 20 within body cavities 30, 32 rather than at the center of the body cavity or substantially at the center of the body cavity. For example, device 10 may be oriented close to the wall of body cavity 30, where needle 17 will exit body cavity 30. This can provide a shorter ultrasound signal path and / or reduce errors, for example, as needle 17 passes through the space within the cavity. In another example, device 10 may be oriented close to the wall of body cavity 30 opposite to the wall of body cavity 30, where needle 17 will exit body cavity 30. This can provide, for example, a robust surface for needle 17 to press against. In yet another example, device 20 may be oriented close to the wall of body cavity 32, where needle 17 will enter body cavity 32. This can provide, for example, a shorter ultrasound signal path. Other device orientations that are neither central nor close to the vessel wall are also possible (e.g., fractions of the diameter away from the lumen wall and / or center, such as 1 / 2, 1 / 3, 1 / 4, etc.).

[0344] Example

[0345] The methods and systems described herein demonstrate specific applications in cardiovascular surgery according to several embodiments. Some aspects are further illustrated by the following non-limiting examples, in which the system is used by clinicians to perform procedures for arteriovenous connection (PICVA), thereby enabling retrograde perfusion of cardiac tissue after coronary artery occlusion.

[0346] The launching catheter 10 is inserted into the occluded coronary artery using standard keyhole surgical techniques (e.g., tracing over a guidewire and tracing through a guiding catheter). The target catheter 20 is inserted into a coronary vein extending parallel to the coronary artery using standard keyhole surgical techniques (e.g., tracing over a guidewire and tracing through a guiding catheter). The coronary vein is not occluded and, therefore, provides an alternative pathway for blood flow to the myocardium, effectively bypassing the occlusion in the coronary artery.

[0347] The transmitting catheter 10 includes a PZT ultrasound transducer 12 (e.g., available from CTS Piezoelectric Products, Albuquerque, New Mexico, USA), which is oriented such that, in this example, a directional ultrasound beam is transmitted at a 45° angle (relative to the longitudinal axis of the transmitting device), preferably in the direction of blood flow in the artery 30, but other angles, including approximately 90°, are also possible. The ultrasound transducer 12 is activated, and in this example, a directional ultrasound signal 40 of 30 MHz is transmitted from the transmitting catheter 10, but other frequencies are also possible. The target catheter 20 includes an omnidirectional ultrasound receiving transducer 60. To aid in the positioning of both the transmitting catheter 10 and the target catheter 20, both catheters 10 and 20 include a centering or orientation device, which in this example is in the form of an annular inflatable balloon 111, but other centering or orientation devices are also possible, or the absence of a centering or orientation device is also possible. Once the transmitting catheter 10 is deemed to be in a suitable position near the occlusion site within the coronary artery 30, a centering device 111 on the transmitting catheter 10 is deployed by the clinician. This can be determined via standard fluorescence imaging techniques and / or based on physical resistance. The target catheter 20 is then moved within the adjacent coronary vein 32 until a guided ultrasound signal 40 is detected by the signal receiving transducer 60. To achieve more precise alignment between the transmitting catheter 10 and the target catheter 20, the centering device 111 on the target catheter 20 can be deployed before or after the detection of the signal 40.

[0348] After receiving the transmitted signal 40, the clinician can confirm that both the transmitting catheter 10 and the target catheter 20 are correctly positioned, both rotationally and longitudinally, within their respective vessels 30, 32, to allow initiation of the arterial-venous connection procedure. The target catheter 20 can be used to occlude blood flow within the coronary vein 32 by applying gel occlusive material 251 through the passage 25 in the target catheter 20. The occlusive material 251 can be applied at a location downstream of the venous blood flow in the coronary vein 32 relative to the position of the receiving transducer 60.

[0349] Clinicians can then initiate a venous-arterial connection by deploying a hollow needle 17 from the transmitting catheter 10 along a path that is parallel to and close to the path taken by the ultrasound signal 40 through the intercalation tissue 34 between the coronary artery 30 and the coronary vein 32, or a path through which the hollow needle 17 intersects the ultrasound signal path at a point within the coronary vein 32. The hollow needle 17 optionally includes a sensor 19 near its tip, configured to detect changes in hydrostatic pressure or Doppler flow, allowing the user to monitor the transition from arterial to venous pressure as the hollow needle 17 passes between the two vessels 30, 32. Optionally, the hollow needle 17 includes a guidewire 14 in the orifice or lumen of the hollow needle 17 during deployment. Once the hollow needle 17 and guidewire 14 have passed through the intercalation tissue 34, the hollow needle 17 can be retracted into the lumen 13 of the transmitting catheter 10, leaving the guidewire 14 in place. In some embodiments, once the hollow needle 17 has passed through the intercalary tissue 34, the user can separately pass the guide wire 14 through the hole or lumen of the hollow needle 17 and then retract the needle 17 back into the firing catheter 10.

[0350] The clinician withdraws the firing catheter 10 from the patient, leaving the guidewire 14 in place. The further catheter device then slides along the guidewire 14. Figure 7 A schematic illustration shows a prosthesis 26 (such as an expandable stent 26) in place after a procedure such as arteriovenous arterialization. Further details regarding possible prostheses containing stents and stent grafts are provided below. The stent 26 can be deployed to widen a perforation in the intercalary tissue 34 between the coronary artery 30 and the coronary vein 32, where discontinuous arrow A indicates the direction of blood flow through the stent 26 between the first and second body cavities 30, 32 (e.g., arterial blood thus diverts to the venous system and is able to retrogradely perfuse myocardial tissue). The stent 26 can occlude upward flow in body cavity 32, forcing blood flow in body cavity 32 to be in the same direction as blood flow in body cavity 30. The graft material of the stent 26 can form a liquid-tight cavity between body cavities 30 and 32. The target catheter 20 is withdrawn from the patient, leaving the occlusive material 251 in place. Optionally, further occlusion or suturing can be inserted into the coronary vein to inhibit or prevent the reversal of arterial blood flow, as described in further detail herein.

[0351] While the specific examples described above pertain to cardiovascular surgery, the methods and systems described herein have far-reaching applications in other forms of surgery. For example, any procedure requiring the guidance of treatment from one body cavity (e.g., for treating peripheral artery disease) towards another adjacent cavity can be considered. Therefore, applications in neurosurgery, urology, and general vascular surgery are also possible. This type of treatment is not limited to creating pathways between body cavities. For example, the methods and systems described herein can also be used in guided techniques such as catheter ablation, non-contact mapping of the ventricles, delivery of drugs to precise areas of the body, and the like.

[0352] The above describes certain techniques for effectively bypassing arterial occlusions via percutaneous surgery. These techniques involve establishing a pathway or channel between a first channel and a second channel adjacent to the first channel to interconnect the first and second channels via a third channel, where the first channel is such as an artery, vein, or ventricle upstream of the occlusion, and the second channel is such as an artery, vein, or ventricle. Fluids such as blood can be diverted from the first channel into the second channel via the interconnecting third channel. In embodiments where the first channel includes an artery and the second channel includes a vein, arterial blood can be perfused into the tissue in a retrograde manner (retrograde perfusion).

[0353] As described above, the interconnecting channel between the first and second body channels can be established, for example, by deploying a needle outward from a first catheter located within the first channel so that the needle passes through the interstitial tissue or septum between the first and second channels. A second catheter can be located in the second channel, thus providing a target device for receiving signals (e.g., ultrasound signals) transmitted from the first catheter. By monitoring the received signals, the position of the first catheter relative to the second catheter can be determined, thereby ensuring that the needle is deployed in the correct position and orientation to establish a channel for fluid flow between the first and second channels.

[0354] To provide or maintain blood flow through interconnected channels or pathways, a lumen-containing structure may be inserted into the channel to support interstitial tissue and / or to inhibit or prevent channel closure. For example, as described herein, the catheter may include a stent that expands or self-expands within the pathway using a balloon catheter. The catheter delivering this structure (e.g., a balloon catheter or a self-expanding catheter) may be guided into the pathway by a guidewire deployed within the channel by a first catheter.

[0355] Channels such as arteries, veins, and ventricles can pulsate with the heartbeat, for example, due to movement of the heart wall, peripheral limbs, and / or fluctuations in pressure within the channel itself. This pulsation can cause movement of the channels relative to each other, which can impose stress on the structures within the interconnecting channels. This stress can be significant compared to the stress experienced by a structure within a single channel. For example, stress can lead to premature structural failure due to fatigue failure of a stent strut. This structural failure can result in damage to interstitial tissue and / or occlusion of interconnecting channels, potentially leading to significant complications or complete treatment failure.

[0356] Figure 8 The illustration depicts a device, implant, or prosthesis 100 for providing or maintaining fluid flow through at least one channel. The device 100 includes a first or proximal portion 102, a second or distal portion 104, and an intermediate portion 106 between the proximal and distal portions 104. The device includes an orifice or lumen 110 for fluid to pass through the device 100. The device 100, for example, at least the intermediate portion 106, includes a flexible polymer tube 108. The flexible polymer tube 108 may at least partially define the lumen 110.

[0357] Device 100 includes a support structure (e.g., at least one support) comprising mesh 112 and mesh 114. In some embodiments, at least a portion of mesh 112 is embedded in the outer wall of tube 108 near the proximal portion 102 of device 100. In some embodiments, at least a portion of mesh 114 (e.g., wire or post) is embedded in the outer wall of tube 108 near the distal portion 104 of device 110. Meshes 112, 114 may comprise biocompatible metals (such as stainless steel) and / or shape memory materials (such as nitinol or chromium cobalt).

[0358] The wire mesh 112 and 114 can respectively stiffen the ends 102 and 104. In some embodiments where the intermediate portion 106 does not include the mesh, the intermediate portion 106 can be relatively flexible compared to the ends 102 and 104, and / or the ends 102 and 104 can have relatively high radial stiffness.

[0359] In some embodiments, the ends 102, 104 of the device 100 are diametrically expandable. For example, the wire meshes 112, 114, after being formed or manufactured, may have a smaller diameter than the channel (such as a blood vessel) in which the device 100 will be deployed. When the device 100 is in a suitable position in the channel, the ends 102, 104 may expand or deform outward so that the respective diameters of the ends 102, 104 increase, for example, to abut the inner sidewalls of the channel. The ends 102, 104 are configured to maintain the expanded diameter indefinitely, for example, by plastic deformation of the material (e.g., wire, support) of the meshes 112, 114 and / or by providing a locking mechanism arranged to mechanically lock the meshes 112, 114 in the expanded position. The intermediate portion 106 of the device 100 may be diametrically expandable, for example, via plastic deformation of the tube 108.

[0360] Figure 9 Show Figure 8 The device 100 is deployed to provide a fluid flow path between a first channel 116 and a second channel 118. Channels 116, 118 may include coronary vessels, such as coronary arteries 116 and coronary veins 118, or vice versa. Channels 116, 118 may include peripheral vessels (e.g., vessels in the limbs), such as the femoral artery or other peripheral artery 116 and the femoral vein or other peripheral vein 118, or vice versa. The ends 102, 104 and the intermediate portion 106 of the device 100 have been expanded to contact and press against the inner walls of the channels 116, 118. The distal portion 104 of the device 100 is located within the second channel 118, and the proximal portion 102 of the device 100 is located within the first channel 116. The intermediate portion 106 extends through a surgically formed opening or interconnecting channel 130 between the channels 116, 118.

[0361] The expanded ends 102, 104 of device 100 are elastic and exert an outward radial force on the inner walls of channels 116, 118. Due to the radial rigidity of ends 102, 104, ends 102, 104 are held or anchored in place within their respective channels 116, 118. Slippage of device 100 within channels 116, 118 is thus prevented or reduced. In this way, ends 102, 104 can anchor or fix device 100 in place while providing or maintaining fluid flow through the inner cavity 110 of tube 108 during use. Figure 8 In this way, device 100 can act as a branch between the first channel 116 and the second channel 118.

[0362] The intermediate portion 106 of the device 100 can be flexible, for example, allowing the intermediate portion 106 to form an 'S' shape formed by a combination of the first channel 116, the second channel 118, and the interconnecting channel 130. Figure 9 In response to the relative movement of channels 116, 118, the flexible intermediate portion 106 may allow the ends 102, 104 of the device 100 to move relative to each other.

[0363] In embodiments where the intermediate portion 106 does not include a wire mesh but comprises a tube 108 of a flexible polymer material, the intermediate portion 106 may not be easily damaged by wire fatigue caused by cyclic or other stresses imparted, for example, during relative movement through channels 116, 118.

[0364] The intermediate portion 106 of the device 100 has sufficient elasticity to maintain the expansion of the interconnecting channel 130 so that the interconnecting channel 130 remains open to provide or maintain a blood flow path from the artery 116 to the vein 118 via the lumen 110 of the tube 108. Figure 8 Blood flow from artery 116 to vein 118 via interconnecting channel 130 can thus be provided or maintained through the lumen 110 of tube 108. Device 100 at least partially supports artery 116, vein 118 and interconnecting channel 130, thereby providing a path for fluid communication through device 100.

[0365] The proximal portion 102 and distal portion 104 of the device 100 are arranged such that, when the device 100 is deployed with the distal portion 104 in a vein 118 and the proximal portion 102 in an artery 116, for example as Figure 9 As shown, the diameter of the dilated distal portion 104 is sufficient to keep the distal portion 104 within the vein 118, and the diameter of the dilated proximal portion 102 is sufficient to keep the proximal portion 102 within the artery 116. The diameter of the proximal portion 102 can therefore differ from the diameter of the distal portion 104. By selecting suitable diameters for the distal portions 102 and 104 and the intermediate portion 106, the device 100 can be customized for certain anatomical structures and / or the anatomy of an individual patient.

[0366] The method used for positioning will now be described. Figure 8 The device 100 provides an example procedure for achieving retrograde perfusion of arterial blood by providing a shunt between an occluded artery 116 and vein 118 (e.g., coronary artery 116 and coronary vein 118, or peripheral artery 116 and peripheral vein 118), such as... Figure 9 As shown in the figure.

[0367] A catheter can be inserted into a patient's arterial system via a small incision typically made in the patient's groin area. The catheter is supplied to artery 116 and guided to a location upstream of the occlusion site, such as near and parallel to or substantially parallel to vein 118. A hollow needle is deployed from the catheter through the wall of artery 116, through interstitial tissue 132 separating artery 116 and vein 118, and through the wall of vein 118. The needle's path establishes an interconnecting channel or opening 130 that allows blood to flow between artery 116 and vein 118. Needle deployment can be guided by a transmitter (e.g., a directional ultrasound transmitter) coupled to the catheter in artery 116 and a receiver (e.g., an omnidirectional ultrasound receiver) coupled to the catheter in vein 118, or vice versa, as described herein and in U.S. Patent Application No. 11 / 662,128. Other methods of forming opening 130 are also possible (e.g., from vein to artery, with or without directional ultrasound guidance, using other types of guidance such as those described herein, etc.).

[0368] Before the needle is retracted from channel 130, the guidewire (e.g., as per the description) is inserted. Figure 3 The guidewire 14 (as described) is inserted through the hollow needle and into the vein 118. The needle is then retracted, leaving the guidewire in the proper position within the artery 116, channel 130, and vein 118. The catheter carrying the needle can then be retrieved from the patient's body. The guidewire can be used to guide further catheters to the interconnecting channel 130 between the artery 116 and vein 118.

[0369] A catheter carrying the non-dilated device 100 is advanced toward the interconnecting channel 130, guided by a guidewire, for example by a rapidly exchanging lumen or guided through the lumen 110. For example, the catheter may include a balloon catheter configured to dilate at least a portion of the device 100 and / or a catheter configured to allow self-dilation of at least a portion of the device 100. The distal portion 104 of the device 100 passes through the interconnecting channel 130 and enters a vein 118, leaving the proximal portion 102 in an artery 116. The intermediate portion 106 of the device 100 is at least partially within the channel 130 and at least partially within both the artery 116 and the vein 118. The intermediate portion 106 is curved to adopt a curved or “S”-shaped configuration, depending on the anatomy of the site. Such curvature allows the shape of the intermediate portion 106 extending through the interconnecting channel 130 and optionally into at least one of the channels 116, 118 to conform to the shape of at least the interconnecting channel 130.

[0370] For example, the distal portion 104 of device 100 expands after balloon inflation or by self-expansion, thereby increasing the diameter of the distal portion 104 and anchoring it against the inner wall of vein 118. The catheter may be adapted to expand the intermediate portion 106 of device 100, for example, by balloon inflation, so that the interconnecting channel 130 can be widened or enlarged to obtain blood flow (e.g., sufficient blood flow) from artery 116 to vein 118. For example, the proximal portion 102 of device 100 expands after balloon inflation or by self-expansion, thereby increasing the diameter of the proximal portion 102 and anchoring it against the inner wall of artery 116.

[0371] After the ends 102, 104 of device 100 have dilated, for example due to self-dilation and / or balloon dilation, and whether the dilation has improved or not after deployment, the catheter and guidewire are withdrawn from the patient's body. In this way, device 100 is anchored or secured in the appropriate location within vein 118, artery 116, and interconnecting channel 130, such as... Figure 9 As shown in the illustration. In embodiments where device 100 includes a stent graft, a graft that can form a liquid-tight channel between artery 116 and vein 118 can inhibit or prevent antegrade blood flow in vein 118 because such a channel is blocked, which can be an addition to or a replacement for the occlusive agent in vein 118 in addition to the occlusive agent in vein 118.

[0372] The catheter may be adapted to selectively dilate, individually or in combination, the proximal portion 102, the distal portion 104, and / or the intermediate portion 106 of the device 100, for example by providing two or more individually inflatable balloons or balloon portions, a single balloon configured to simultaneously dilate all portions of the device 100, or a single balloon configured to dilate one or more selected portions of the device 100. For example, the ends 102, 104 may be self-dilatating, and the intermediate portion 106 may be dilated by balloon expansion to widen the channel 130. In some embodiments including balloon expansion, all portions or selected portions of the device 100 may be simultaneously dilated, for example, by a balloon extending the entire length of the device 100 or by a plurality of balloons longitudinally spaced to selectively dilate selected portions of the device 100, and / or sequentially dilated by a balloon or a plurality of balloons. In some embodiments including at least partial self-dilatation, all portions or selected portions of the device 100 may be dilated, for example, by proximal retraction of a sheath on or around the device 100, which may result in the device 100 being deployed from distal to proximal as the sheath retracts proximally. Deploying device 100 from proximal to distal and from midway to both ends are also possible. In some embodiments, such as where device 100 is at least partially conical or tapered, a conical or tapered balloon may be used to at least partially dilate device 100. In some such embodiments, the portion of the balloon closer to vein 118 may have a larger diameter than the portion closer to artery 116, for example, so that device 100 can be adapted to changes in vein diameter due to any increase in pressure or blood flow in vein 118.

[0373] Other steps may be included in the procedure. For example, prior to device 100 deployment, a balloon catheter may be guided to and positioned in the interconnecting channel 130 such that the inflatable balloon portion of the catheter is located within the interconnecting channel 130. After balloon inflation, the balloon pushes against the walls of the interconnecting channel 130 to widen or enlarge the interconnecting channel 130 to facilitate subsequent insertion of device 100.

[0374] Figure 10 Another device 134 is illustrated, providing fluid flow through at least one channel. Device 134 includes a mesh 136 and a polymer tube 108. The mesh 136 is shown outside the polymer tube 108, but as described herein, it may also or optionally be on the inside of the polymer tube and / or within the polymer tube 108. As described with respect to device 100, device 134 includes a proximal portion 102, a distal portion 104, and an intermediate portion 106. Figure 10 In the illustrated embodiment, the mesh 136 extends along the entire length of the device 134, including along the middle portion 106.

[0375] In some embodiments, the spacing of the filaments or supports of the mesh 136 varies along the length of the device 134. For example, the winding density of the woven or layered filament mesh can be changed and / or the window size of the mesh can be altered.

[0376] In some embodiments, the spacing may be relatively small in the proximal portion 102 and the distal portion 104, and relatively large in the intermediate portion 106. In other words, the density or window size of the mesh 136 may be relatively low in the intermediate portion 106, and relatively high in the ends 102, 104. In some such embodiments, the intermediate portion 106 may be flexible compared to the ends 102, 104. The relatively rigid ends 102, 104 may engage and anchor in the channel. While the mesh 136 in the intermediate portion 106 can withstand stresses such as cyclic stress, in use, the relatively high flexibility of the intermediate portion 106 due to its low density or window size results in a lower impact from stress, as the intermediate portion is able to flex in response to stress. The risk of fatigue failure of the device 134 and specifically the filaments or supports 138 of the mesh 136 can therefore be reduced compared to a device with uniform flexibility along its entire length.

[0377] In some embodiments, the spacing may be relatively large in the proximal portion 102 and the distal portion 104, and relatively small in the intermediate portion 106. In other words, the density of the mesh 136 may be relatively high in the intermediate portion 106 (or the window size of the mesh 136 may be relatively small), and the density of the mesh 136 may be relatively low in the ends 102, 104 (or the window size of the mesh 136 may be relatively large). In some such embodiments, the intermediate portion 106 may have radial strength sufficient to suppress or prevent collapse of the channel 130, yet remain flexible enough to flex in response to stresses such as cyclic stress. The ends 102, 104 may be engaged and anchored within the channel.

[0378] Figure 11The illustration shows another device, implant, or prosthesis 140 that provides fluid flow through at least one channel. As described with respect to device 100, device 140 includes a proximal portion 102, a distal portion 104, and an intermediate portion 106. Device 140 includes a polymer tube 108 and a support structure comprising a first mesh 142 and a second mesh 144. The first mesh 142 extends from the proximal portion 102 toward (e.g., into) the intermediate portion 106 and optionally into the distal portion 104. The second mesh 144 extends from the distal portion 104 toward (e.g., into) the intermediate portion 106 and optionally into the proximal portion 102. The meshes 142, 144 thus overlap each other at least at the intermediate portion 106. Both meshes 142 and 144 can be on the outside of tube 108, on the inside of tube 108, or embedded in tube 108. Alternatively, one mesh can be on the outside of tube 108, on the inside of tube 108, or embedded in tube 108, while other meshes are differently on the outside of tube 108, on the inside of tube 108, or embedded in tube 108 (e.g., one mesh on the inside of tube 108 and one mesh on the outside of tube 108). Meshes 142 and 144 can be formed, for example, by a mesh constructed around or inside the polymer tube 108, by placing a cut tube around or inside the polymer tube 108, by being embedded in the polymer tube 108, or a combination thereof, or the like.

[0379] In some embodiments, the density of the meshes 142, 144 is relatively high (or the window size of the meshes 142, 144 is relatively small) at their respective ends 102, 104 and decreases (or increases) towards the middle portion 106. The total winding density (e.g., the combined winding density of the meshes 142, 144) may be lower in the middle portion 106 than at the ends 102, 104, or the total window size (e.g., the combined window size of the meshes 142, 144) may be larger in the middle portion 106 than at the ends 102, 104. In some such embodiments, the middle portion 106 is relatively flexible compared to the ends 102, 104. In some embodiments, the meshes 142, 144 do not extend into the middle portion, and there is no mesh that allows the middle portion 106 to be relatively flexible compared to the ends 102, 104. In some implementations, as the window size (e.g., longitudinally along the tapered portion of the device 140) increases, the density decreases, the mesh coverage decreases, and / or the porosity increases because the width of the struts and / or filaments remains substantially constant or constant or does not increase in the same proportion as the window size. This can provide flexible changes along the longitudinal length.

[0380] The first mesh 142 and the second mesh 144 may comprise different materials. For the specific application of the device 140, different materials can allow for performance optimization of each of the respective distal and proximal portions 102, 104 of the device 140. For example, the second mesh 144 at the distal portion 104 of the device 140 may comprise a relatively flexible metallic alloy for easy insertion into the interconnecting channel between two blood vessels, while the first mesh 142 at the proximal portion 102 of the device 140 may comprise a relatively inelastic metallic alloy to provide high elasticity at the proximal portion 104, thereby firmly anchoring the device 140 in place. The first mesh 142 and the second mesh 144 may comprise the same material composition (e.g., both containing nitinol) but include different wire diameters (gauges) or strut thicknesses.

[0381] Figure 12 The illustration depicts another device, implant, or prosthesis 150 providing fluid flow through at least one channel. Device 150 includes a support structure (e.g., a stent) 152 and a graft 154. As described with respect to device 100, device 150 includes a proximal portion 102, a distal portion 104, and an intermediate portion 106. The proximal portion 102 includes a cylindrical or generally cylindrical section, and the distal portion 104 includes a cylindrical / cylindrical or generally cylindrical / cylindrical section. The diameter of the proximal portion 102 is smaller than the diameter of the distal portion 104. In some embodiments, the diameter of the proximal portion 102 is larger than the diameter of the distal portion 104. The intermediate portion 106 has a tapered or truncated tapered / truncated conical shape between the proximal portion 102 and the distal portion 104. The stent 152 may include filaments (e.g., woven, layered), cut tubes or plates, and / or combinations thereof.

[0382] The parameters of the stent 152 may be uniform or substantially uniform across one portion and / or multiple portions, or may vary within one portion and / or across multiple portions. For example, the stent 152 at the proximal portion 102 may include a cut tube or plate, the stent 152 at the distal portion 102 may include a cut tube or plate, and the stent 152 at the intermediate portion 106 may include filaments (e.g., woven or layered). Some such embodiments may provide good anchoring through the good flexibility (e.g., adaptability to third channel size and dynamic stress) of the proximal portion 102, the distal portion 104, and the intermediate portion 106.

[0383] The stent 152 may contain different materials in different portions. For example, the stent 152 at the proximal portion 102 may contain chromium cobalt and / or tantalum, the stent 152 at the distal portion 104 may contain nitinol, and the stent 152 at the intermediate portion 106 may contain nitinol. Some such embodiments may provide good anchoring and / or wall attachment through the device 150 in each deployment region (e.g., the proximal portion 102 engages the sidewall of an artery, the distal portion 104 engages the sidewall of a vein, and the intermediate portion 106 engages the sidewall of the passage between the artery and vein). In some embodiments where the distal portion 104 is self-expanding, the distal portion 104 may be adapted, for example, by further self-expanding due to a change in the vessel diameter (e.g., if the vein diameter increases due to an increase in blood pressure or blood flow).

[0384] Combinations of support structure materials and types are also possible. For example, the support 152 at the proximal portion may include a cut tube or plate containing chromium cobalt and / or tantalum, the support 152 at the distal portion 104 may include a cut tube or plate containing nitinol, and the support 152 at the intermediate portion 106 may include filaments containing nitinol.

[0385] In embodiments where the support 152 includes at least a portion comprising a cut tube or plate, the cut pattern may be identical. For example, the cut pattern may be identical in the proximal portion 102 and the distal portion 104, but proportional to the change in diameter. In some embodiments, the window size or strut density is uniform or substantially uniform within portions 102, 104, 106, in two or more portions 102, 104, 106, and / or from one end of the support 152 to the other end of the support 152. In embodiments where the support 152 includes at least a portion comprising filaments, the winding may be identical. For example, the winding may be identical in the proximal portion 102 and the distal portion 104, but varies due to the change in diameter. In some embodiments, the winding density or porosity is uniform or substantially uniform within portions 102, 104, 106, in two or more portions 102, 104, 106, and / or from one end of the support 152 to the other end of the support 152. In embodiments where the support 152 includes at least a portion comprising a cut tube or plate and at least a portion comprising filaments, the cutting pattern and winding can be configured to result in a uniform or substantially uniform density. Non-uniformity is also possible, for example as described herein.

[0386] As described with respect to tube 108, graft 154 may include material and be attached to support 152. Graft 154 typically forms a liquid-tight channel for at least a portion of device 150. Although the illustration focuses only on the central portion 106, graft 154 may extend the entire length of device 150 or may partially overlap at least one of the cylindrical ends 102, 104.

[0387] Figure 13 Another device 160 is illustrated, providing fluid flow through at least one channel. Device 160 includes a support structure (e.g., a support frame) and a graft 164. As described with respect to device 100, device 160 includes a proximal portion 102, a distal portion 104, and an intermediate portion 106. The proximal portion 102 includes a tapered or truncated tapered section, and the distal portion 104 includes a tapered or truncated tapered section. The diameter of the proximal end of the proximal portion 102 is smaller than the diameter of the distal end of the distal portion 104. In some embodiments, the diameter of the proximal end of the proximal portion 102 is larger than the diameter of the distal end of the distal portion 104. The intermediate portion 106 has a tapered or truncated tapered shape between the proximal portion 102 and the distal portion 104. In some embodiments, the angles of inclination of portions 102, 104, and 106 are the same or substantially the same (e.g., as shown in the diagram). Figure 13 (As illustrated in the figure). In some embodiments, the angle of inclination of at least one portion is sharper or narrower than that of at least one other portion. The truncated conical proximal portion 102 and distal portion 104 can allow for better anchoring in body passages, for example, because arteries tend to conicalize with distance from the heart, and veins tend to conicalize with distance towards the heart, and the ends 102, 104 can be configured to at least partially correspond to such anatomy in a conical shape.

[0388] Figure 12 The illustration shows a device 150, which includes a first cylindrical or straight portion, a conical or tapered portion, and a second cylindrical or straight portion. Figure 13The illustration shows a device 160 that includes one or more conical or tapered sections (e.g., the entire device 160 is conical or tapered or includes multiple conical or tapered sections). In some embodiments, combinations of devices 150 and 160 are possible. For example, for the remainder of the device, the device may include cylindrical or straight portions and conical or tapered portions. In some such embodiments, the length of the device can be between about 1 cm and about 10 cm (e.g., about 5 cm), comprising a cylindrical or straight portion and a conical or tapered portion. The diameter of the cylindrical or straight portion is between about 1 mm and about 5 mm (e.g., about 3 mm) and the length is between about 0.5 cm and about 4 cm (e.g., about 2 cm). The diameter of the conical or tapered portion increases from the diameter of the cylindrical or straight portion to a diameter between about 3 mm and about 10 mm (e.g., about 5 mm) and the length is between about 1 cm and about 6 cm (e.g., about 3 cm). Such a device may subsequently omit another cylindrical or conical portion.

[0389] As described above with respect to support structure 152, support structure 162 may include filaments (e.g., woven, layered), cut tubes or plates, the same material, different materials, and combinations thereof.

[0390] As described with respect to tube 108, graft 164 may include material and be attached to support 162. Graft 164 typically forms a liquid-tight channel for at least a portion of device 160. Although illustrated only around the central portion 106, graft 164 may extend the entire length of device 160 or may partially overlap at least one of the truncated conical ends 102, 104.

[0391] In some embodiments, combinations of devices 150 and 160 are possible. For example, the proximal portion 102 may be cylindrical or generally cylindrical (e.g., as in device 150), and the distal portion 104 may be tapered or truncated tapered (e.g., as in device 160), with the proximal portion 102 having a larger diameter than the distal end of the distal portion 104. For another example, the proximal portion 102 may be tapered or truncated tapered (e.g., as in device 160), and the distal portion 104 may be cylindrical or generally cylindrical (e.g., as in device 150), with the proximal end of the proximal portion 102 having a larger diameter than the distal portion 104. In each example, the intermediate portion 106 may have a tapered or truncated tapered shape between the proximal portion 102 and the distal portion 104.

[0392] Example deployment devices for the implantable device described herein are described in U.S. Patent Application No. 12 / 545,982, filed August 24, 2009, and U.S. Patent Application No. 13 / 486,249, filed June 1, 2012, the entire contents of each of which are incorporated herein by reference. The device typically includes a combination of a handle at the proximal end having a user-actuable trigger and a tubular member at the distal end configured to be pushed and / or pulled to release the device upon trigger actuation. Other delivery devices are also possible. Delivery devices may include a slidable portion on a guidewire (e.g., a guidewire already guided through tissue traversing between arteries and veins) and / or may be traceable through the lumen of a catheter.

[0393] While certain implementations and examples are shown or described in detail herein, different combinations, sub-combinations, modifications, variations, substitutions, and omissions of specific features and aspects of those implementations are possible, some of which will now be described by way of example only.

[0394] Devices, such as stents, meshes, and support structures, can be self-expanding. For example, the mesh may include a shape memory material, such as nitinol, which returns to a predetermined shape after deformation. In some embodiments, the stent may be manufactured to the desired shape in an expansion configuration and is compressible to fit within a sleeve for transport over a catheter to a vascular site. To deploy and expand the stent, the sleeve is withdrawn from the stent to allow the shape memory material to return to its predetermined shape, which anchors the stent in the channel and, if the stent has sufficient radial strength, allows the channel to expand. The use of balloon catheters does not require the expansion of a fully self-expanding stent, but can be used, for example, to improve or optimize deployment.

[0395] The device may include one or more self-expanding sections, and one or more sections that are expandable by deformation, for example, using a balloon catheter. Figure 11 In the illustrated embodiment, the first mesh 142 may comprise expandable stainless steel via a balloon catheter, and the second mesh 144 may comprise self-expanding nitinol after deployment.

[0396] Regarding any of the embodiments described herein, the polymer tube 108 comprising grafts 154, 164 may comprise any suitable compliant or flexible polymer, such as PTFE, silicone, polyethylene terephthalate (PET), polyurethane such as polycarbonate, aromatic biodegradable thermoplastic polyurethane elastomers (e.g., ChronoFlex). Medical-grade 80A and 55D materials are available from AdvanSource Biomaterials, Wilmington, Massachusetts, and combinations thereof. The polymer tube 108 may comprise biodegradable, bioabsorbable, or biocompatible polymers (e.g., polylactic acid (PLA), polyglycolic acid (PGA), polyglycolic acid-lactic acid (PLGA), polycaprolactone (PCL), polyorthoesters, polyanhydrides, combinations thereof, etc.). The polymer may be in tube form before interacting with a support structure (e.g., a stent), or may be formed on, in, or around a support structure (e.g., a stent). For example, the polymer may comprise spun fibers, impregnated coatings, combinations thereof, etc. In some embodiments, such as when the device is to be deployed in a single blood vessel, the tube may be omitted. In some such embodiments, the intermediate portion of the stent may include a mesh with a low winding density or a large window size, while the ends of the stent include a mesh with a higher winding density or a smaller window size, the mesh being generally tubular to define a path for fluid flow through the center of the mesh. In some embodiments, the polymer tube 108 includes edges (e.g., comprising the same or different materials) that can help form a liquid-tight seal between the polymer tube 108 and the body channel. This seal may be angled, for example, to accommodate an angled arrangement of the polymer tube 108 between the body channels. In some embodiments, the polymer tube 108 may extend longitudinally beyond the support structure in at least one direction, and the extended portion may not be supported by the support structure.

[0397] The mesh can comprise any suitable material, such as nickel, titanium, chromium, cobalt, tantalum, platinum, tungsten, iron, manganese, molybdenum, combinations thereof (e.g., nickel-titanium, chromium-cobalt, stainless steel), and the like. The mesh can comprise biodegradable, bioabsorbable, or biocompatible polymers (e.g., polylactic acid (PLA), polyglycolic acid (PGA), polyglycolic acid-lactic acid (PLGA), polycaprolactone (PCL), polyorthoesters, polyanhydrides, combinations thereof, etc.) and / or glass, and may lack metal. For example, as mentioned above... Figure 11As described, different materials may be used for portions of the mesh or within the same mesh. For example, the mesh 114 at the distal portion 104 and the mesh 112 at the proximal portion 102 of device 100 may comprise different materials. For another example, mesh 112 and / or mesh 114 may comprise metal alloys (e.g., including cobalt, chromium, nickel, titanium, combinations thereof, and the like) combined with different types of metal alloys (e.g., shape memory alloys combined with non-shape memory alloys, a first shape memory alloy combined with a second shape memory alloy different from the first shape memory alloy, clad materials (e.g., including a core comprising a radiopaque material such as titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, etc.)) and / or non-metallic materials such as polymers (e.g., polyester fibers), carbon, and / or bioabsorbable glass fibers. In some embodiments, at least one mesh 112, 114 comprises nitinol and stainless steel. Nitinol can allow some self-expansion (e.g., partial and / or full self-expansion), and the mesh can then be further expanded, for example, using a balloon.

[0398] Although Figure 8 , Figure 10 and Figure 11 The illustration typically depicts a woven mesh of fine filaments, but any other structure that provides the desired elasticity can be used. For example, layers of filaments wound in opposite directions can be fused at the ends of the filaments to provide an expandable structure. As another example, a sheet of metal can be cut (e.g., laser cutting, chemical etching, plasma cutting, etc.) to form perforations and then heat-set into a tubular shape, or a metal tube (e.g., a sodium hypochlorite tube) can be cut (e.g., laser cutting, chemical etching, plasma cutting, etc.) to form perforations. Cut tubes (including cut plates rolled into tubes) can be heat-set to impart an expandable structure.

[0399] The filaments, threads, or strips that can be woven or braided, layered, or otherwise arranged are typically elongated and have a circular, elliptical, square, rectangular, or other cross-section. Example nonwoven filaments may include a first layer of filaments wound in a first direction and a second layer of filaments wound in a second direction, with at least some of the filament ends coupled together (e.g., by coupling to expandable loops). Example braiding patterns include one-over-one-under-one, one-over-two-under-two, two-over-two-under-two, and / or combinations thereof, but other braiding patterns are also possible. At filament crossings, the filaments may be spirally wrapped, cross in a sliding relationship, and / or combinations thereof. The filaments can be loose (e.g., held together by weaving) and / or include weld points, coupling elements such as sleeves, and / or combinations thereof. The ends of the filaments can be bent backwards, coiled (e.g., coiled ends with an end of a translucent material that can also serve as a translucent marker, such as titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, etc.), twisted, ball-welded, coupled to a ring, combinations thereof, and the like. The woven ends can include filament ends and / or backward-bent filaments, and can include open cells, fixed or unfixed filaments, weld points, adhesives, or other means of fusion, translucent markers, combinations thereof, and the like. The parameters of the filaments throughout one and / or multiple portions can be uniform or substantially uniform, or can vary within one portion and / or throughout multiple portions. For example, the proximal portion 102 can include a first parameter and the distal portion 104 can include a second parameter different from the first weave pattern. In another example, the proximal portion 102 and the distal portion 104 may each include a first parameter, and the intermediate portion 106 may include a second parameter different from that parameter. In yet another example, at least one of the proximal portion 102, the distal portion 104, and the intermediate portion 106 may include both the first parameter and a second parameter different from the first parameter. The filament parameters may include, for example, filament type, filament thickness, filament material, number of filaments, weave pattern, layering, winding direction, pitch, angle, crossover type, filament coupling or absence thereof, filament end treatment, weave end treatment, layer end treatment, number of layers, presence or absence of weld points, non-transparent linearity, weave pattern, density, porosity, filament angle, weave diameter, winding diameter, and shape setting.

[0400] Tubes or plates can be cut to form pillars or unit types, where pillars are the portions of the tube or plate remaining after cutting, and units, perforations, or windows are the cut-off portions. Tubes (e.g., hypo tubes) can be cut directly, or plates can be cut and then rolled into tubes. Tubes or plates can be shaped before or after cutting. Tubes or plates can be welded or otherwise coupled to themselves, to another tube or plate, to a filament, to a graft material, etc. Cutting can be performed using lasers, chemical etchants, plasma, combinations thereof, and the like. Example cutting types include helical spirals, woven types, coils, single loops, continuous loops, open / closed units, closed / closed units, combinations thereof, etc. In embodiments involving continuous loops, flexible connectors, non-flexible connectors, and / or combinations thereof can be used to couple the loops. In embodiments incorporating continuous rings, the ring connector (e.g., flexible, non-flexible, and / or combinations thereof) may traverse ring peaks, ring valleys, intermediate portions of struts, and / or combinations thereof (e.g., peak-to-peak, valley-to-valley, middle-to-middle, peak-to-valley, peak-to-middle, valley-to-middle, valley-to-peak, middle-to-peak, middle-to-valley). The tube or plate, or portions thereof, may be ground or polished before or after cutting. For example, internal ridges may be formed to aid fluid flow. The parameters of the cut tube or plate may be uniform or substantially uniform throughout one and / or multiple portions, or may vary within one portion and / or throughout multiple portions. For example, proximal portion 102 may include a first parameter, and distal portion 104 may include a second parameter different from the first parameter. In another example, proximal portion 102 and distal portion 104 may each include a first parameter, and intermediate portion 106 may include a second parameter different from that parameter. In yet another example, at least one of proximal portion 102, distal portion 104, and intermediate portion 106 may include both the first parameter and a second parameter different from the first parameter. Cutting parameters for tubes or plates may include, for example, radial support thickness, circumferential support width, support shape, unit shape, cutting pattern, cutting type, material, density, porosity, tube diameter, and shape settings.

[0401] In some embodiments, perforation can provide a mesh with a relatively flexible middle section and relatively rigid ends. The support structure can instead be open-cell foam arranged within the tube.

[0402] The filaments of the stent, stent graft, or a portion thereof, and / or the struts of the stent, stent graft, or a portion thereof, may be surface-modified, for example, to carry drugs such as thrombosis modifiers, fluid flow modifiers, antibiotics, etc. The filaments of the stent, stent graft, or a portion thereof, and / or the struts of the stent, stent graft, or a portion thereof, may be at least partially covered with a coating including a drug, such as thrombosis modifiers, fluid flow modifiers, antibiotics, etc., embedded within a polymer layer or a series of polymer layers, the polymer layer being the same as or different from the polymer tube 108.

[0403] The thickness (e.g., diameter) of the scaffold, scaffold graft, or filaments and / or cut supports of the scaffold, scaffold graft, or scaffold graft may be between about 0.0005 inches and about 0.02 inches, between about 0.0005 inches and about 0.015 inches, between about 0.0005 inches and about 0.01 inches, between about 0.0005 inches and about 0.008 inches, between about 0.0005 inches and about 0.007 inches, between about 0.0005 inches and about 0.006 inches, between about 0.0005 inches and about 0.005 inches, between about 0.0005 inches and about 0.004 inches, between about 0.0005 inches and about 0.003 inches, and between about 0. Between 0.0005 inches and approximately 0.002 inches, between approximately 0.0005 inches and approximately 0.001 inches, between approximately 0.001 inches and approximately 0.02 inches, between approximately 0.001 inches and approximately 0.015 inches, between approximately 0.001 inches and approximately 0.01 inches, between approximately 0.001 inches and approximately 0.008 inches, between approximately 0.001 inches and approximately 0.007 inches, between approximately 0.001 inches and approximately 0.006 inches, between approximately 0.001 inches and approximately 0.005 inches, between approximately 0.001 inches and approximately 0.004 inches, between approximately 0.001 inches and approximately 0.003 inches, between approximately 0.001 inches and approximately 0.002 inches, in approximately Between 0.002 inches and approximately 0.02 inches, between approximately 0.002 inches and approximately 0.015 inches, between approximately 0.002 inches and approximately 0.01 inches, between approximately 0.002 inches and approximately 0.008 inches, between approximately 0.002 inches and approximately 0.007 inches, between approximately 0.002 inches and approximately 0.006 inches, between approximately 0.002 inches and approximately 0.005 inches, between approximately 0.002 inches and approximately 0.004 inches, between approximately 0.002 inches and approximately 0.003 inches, between approximately 0.003 inches and approximately 0.02 inches, between approximately 0.003 inches and approximately 0.015 inches, between approximately 0.003 inches and approximately 0.01 inches, and between approximately 0. Between approximately 0.003 inches and approximately 0.008 inches, between approximately 0.003 inches and approximately 0.007 inches, between approximately 0.003 inches and approximately 0.006 inches, between approximately 0.003 inches and approximately 0.005 inches, between approximately 0.003 inches and approximately 0.004 inches, between approximately 0.004 inches and approximately 0.02 inches, between approximately 0.004 inches and approximately 0.015 inches, between approximately 0.004 inches and approximately 0.01 inches, between approximately 0.004 inches and approximately 0.008 inches, between approximately 0.004 inches and approximately 0.007 inches, between approximately 0.004 inches and approximately 0.006 inches, between approximately 0.004 inches and approximately 0.005 inches, between approximately 0.004 inches and approximately 0.006 inches, between approximately 0.004 inches and approximately 0.005 inches, between approximately 0.004 inches and approximately 0.006 inches.Between approximately 0.005 inches and approximately 0.02 inches, between approximately 0.005 inches and approximately 0.015 inches, between approximately 0.005 inches and approximately 0.01 inches, between approximately 0.005 inches and approximately 0.008 inches, between approximately 0.005 inches and approximately 0.007 inches, between approximately 0.005 inches and approximately 0.006 inches, between approximately 0.006 inches and approximately 0.02 inches, between approximately 0.006 inches and approximately 0.015 inches, between approximately 0.006 inches and approximately 0.01 inches, between approximately 0.006 inches and approximately 0.008 inches, between approximately 0.006 inches and approximately... The thickness can be between 0.007 inches, between approximately 0.007 inches and approximately 0.02 inches, between approximately 0.007 inches and approximately 0.015 inches, between approximately 0.007 inches and approximately 0.01 inches, between approximately 0.007 inches and approximately 0.008 inches, between approximately 0.008 inches and approximately 0.02 inches, between approximately 0.008 inches and approximately 0.015 inches, between approximately 0.008 inches and approximately 0.01 inches, between approximately 0.01 inches and approximately 0.02 inches, between approximately 0.01 inches and approximately 0.015 inches, or between approximately 0.015 inches and approximately 0.02 inches. Other thicknesses are also possible, including thicknesses greater than or less than the confirmed thickness. Filaments and / or struts containing certain materials (e.g., biodegradable materials, materials with lower resilience, etc.) may be thicker than the confirmed thickness.

[0404] For example, the thickness of the filaments and / or struts can be based on at least one of the following: device or device portion size (e.g., diameter and / or length), porosity, radial strength, material, number of filaments and / or struts, cutting pattern, weaving pattern, layering pattern, and the like. For example, a larger filament and / or strut thickness (e.g., greater than about 0.006 inches) can be used for large devices or device portions for treating large vessels such as coronary vessels, a medium filament and / or strut thickness (e.g., between about 0.003 inches and about 0.006 inches) can be used for medium devices or device portions for treating medium vessels such as peripheral vessels, and a small filament and / or strut thickness (e.g., less than about 0.003 inches) can be used for small devices or device portions for treating small vessels such as veins and neurovascular vessels.

[0405] The inner or outer diameter of the scaffold, scaffold graft, or first end, second end, middle portion, or sub-portion, taking into account, for example, the thickness of the filament or support, can be between approximately 1 mm and approximately 12 mm, between approximately 1 mm and approximately 10 mm, between approximately 1 mm and approximately 8 mm, between approximately 1 mm and approximately 6 mm, between approximately 1 mm and approximately 4 mm, between approximately 1 mm and approximately 2 mm, between approximately 2 mm and approximately 12 mm, between approximately 2 mm and approximately 10 mm, between approximately 2 mm and approximately 8 mm. Between approximately 2mm and 6mm, between approximately 2mm and 4mm, between approximately 4mm and 12mm, between approximately 4mm and 10mm, between approximately 4mm and 8mm, between approximately 4mm and 6mm, between approximately 6mm and 12mm, between approximately 6mm and 10mm, between approximately 6mm and 8mm, between approximately 8mm and 12mm, between approximately 8mm and 10mm, or between approximately 10mm and 12mm. Certain such diameters may be suitable for treatment, for example, coronary arteries. For example, considering the thickness of the filament or strut, the inner or outer diameter of the stent, stent graft, or a portion thereof can be between approximately 1 mm and approximately 10 mm, between approximately 1 mm and approximately 8 mm, between approximately 1 mm and approximately 6 mm, between approximately 1 mm and approximately 4 mm, between approximately 1 mm and approximately 2 mm, between approximately 2 mm and approximately 10 mm, between approximately 2 mm and approximately 8 mm, between approximately 2 mm and approximately 6 mm, between approximately 2 mm and approximately 4 mm, between approximately 4 mm and approximately 10 mm, between approximately 4 mm and approximately 8 mm, between approximately 4 mm and approximately 6 mm, between approximately 6 mm and approximately 10 mm, between approximately 6 mm and approximately 8 mm, or between approximately 8 mm and approximately 10 mm. Certain such diameters may be suitable for treatment, for example, veins. For example, considering the thickness of the filament or strut, the inner or outer diameter of the stent, stent graft, or a portion thereof can be between approximately 6 mm and approximately 25 mm, between approximately 6 mm and approximately 20 mm, between approximately 6 mm and approximately 15 mm, between approximately 6 mm and approximately 12 mm, between approximately 6 mm and approximately 9 mm, between approximately 9 mm and approximately 25 mm, between approximately 9 mm and approximately 20 mm, between approximately 9 mm and approximately 15 mm, between approximately 9 mm and approximately 12 mm, between approximately 12 mm and approximately 25 mm, between approximately 12 mm and approximately 20 mm, between approximately 12 mm and approximately 15 mm, between approximately 15 mm and approximately 25 mm, between approximately 15 mm and approximately 20 mm, or between approximately 20 mm and approximately 25 mm. Certain such diameters may be suitable for treatment, for example, peripheral blood vessels.For example, considering the thickness of the filament or strut, the inner or outer diameter of the stent, stent graft, or a portion thereof can be between approximately 20 mm and approximately 50 mm, between approximately 20 mm and approximately 40 mm, between approximately 20 mm and approximately 35 mm, between approximately 20 mm and approximately 30 mm, between approximately 30 mm and approximately 50 mm, between approximately 30 mm and approximately 40 mm, between approximately 30 mm and approximately 35 mm, between approximately 35 mm and approximately 50 mm, between approximately 35 mm and approximately 40 mm, and between approximately 40 mm and approximately 50 mm. Certain such diameters may be suitable for treatment, for example, the aorta. Other diameters are also possible, including diameters larger or smaller than the identified diameter. The diameter of the device may refer to the diameter of the first end, the second end, or the intermediate portion, each of which may be dilated or undilated. When all portions of the device are dilated or undilated, the diameter of the device may refer to the average diameter of the device.

[0406] The length of the scaffold, scaffold graft, or first end, second end, middle portion, or sub-portion may be between approximately 5 mm and approximately 150 mm, between approximately 5 mm and approximately 110 mm, between approximately 5 mm and approximately 70 mm, between approximately 5 mm and approximately 50 mm, between approximately 5 mm and approximately 25 mm, between approximately 5 mm and approximately 20 mm, between approximately 5 mm and approximately 10 mm, between approximately 10 mm and approximately 150 mm, between approximately 10 mm and approximately 110 mm, between approximately 10 mm and approximately 70 mm, between approximately 10 mm and approximately 50 mm, between approximately 10 mm and approximately 25 mm, between approximately 10 mm and approximately 20 mm, or between approximately 20 mm and approximately 20 mm. Between approximately 150 mm, between approximately 20 mm and approximately 110 mm, between approximately 20 mm and approximately 70 mm, between approximately 20 mm and approximately 50 mm, between approximately 20 mm and approximately 25 mm, between approximately 25 mm and approximately 150 mm, between approximately 25 mm and approximately 110 mm, between approximately 25 mm and approximately 70 mm, between approximately 25 mm and approximately 50 mm, between approximately 50 mm and approximately 150 mm, between approximately 50 mm and approximately 110 mm, between approximately 50 mm and approximately 70 mm, between approximately 70 mm and approximately 150 mm, between approximately 70 mm and approximately 110 mm, or between approximately 110 mm and approximately 150 mm. Other lengths are also possible, including lengths greater than or less than the confirmed length.

[0407] The porosity of the scaffold, scaffold graft, or first end, second end, intermediate portion, or sub-portion thereof may be between about 5% and about 95%, between about 5% and about 50%, between about 5% and about 25%, between about 5% and about 10%, between about 10% and about 50%, between about 10% and about 25%, between about 25% and about 50%, between about 50% and about 95%, between about 50% and about 75%, between about 50% and about 60%, between about 60% and about 95%, between about 75% and about 90%, between about 60% and about 75%, and combinations thereof. The density of the scaffold may be the reciprocal of its porosity. The porosity of the portion of the scaffold covered by the graft may be about 0%. For certain portions of the scaffold, the porosity may vary depending on the purpose. For example, the middle section can have low porosity to increase fluid flow through the device, while the ends can have low porosity to increase flexibility and wall adhesion.

[0408] Figure 25A This is a schematic side view of yet another exemplary embodiment of the prosthesis 500. The prosthesis, stent, or device 500 includes and / or is substantially composed of a plurality of filaments 502 woven together to form a woven structure. The stent 500 may be without graft material, as further detailed below.

[0409] The filaments 502, which can also be described as threads, strips, strands, etc., can be woven, braided, layered, or otherwise arranged in a cross-hatching manner. The filaments 502 are typically elongated and have a circular, elliptical, square, rectangular, or other cross-section. Example nonwoven filaments may include a first layer of filaments wound in a first direction and a second layer of filaments wound in a second direction, with at least some filament ends coupled together (e.g., by coupling to expandable loops). Example woven patterns include one above and one below (as in...). Figure 25A(As shown in the diagram), one over two under two, two over two under two, and / or combinations thereof, but other weaving patterns are also possible. At the intersections of filaments 502, filaments 502 may be spirally wrapped, cross in a sliding relationship, and / or combinations thereof. Fibers 502 may be loose (e.g., held together by weaving) and / or include weld points, coupling elements such as sleeves, and / or combinations thereof. The ends of filaments 502 may be bent backward, curled (e.g., curled at the end with a radiopaque material that can also serve as a radiopaque marker, such as titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, etc.), twisted, ball-welded, coupled to a ring, combinations thereof, and the like. The weaving end may include the end of filament 502 and / or a backward-curved filament 502, and may include open cells, fixed or non-fixed filaments 502, weld points, adhesives, or other means of fusion, radiopaque markers, combinations thereof, and the like.

[0410] The support 500 includes open, uncovered areas between pores 504 or filaments 502. The porosity of the support 500 can be calculated as the outer surface area of ​​the pores 504 divided by the total outer surface area of ​​the support 500. Porosity can be affected by parameters such as, for example, the number of filaments 502, the braiding angle 506, the size (e.g., diameter) of the filaments 502, and combinations thereof.

[0411] The porosity of the stent 500 can be less than 50% (e.g., slightly more covered than open), between about 0% (e.g., almost no open area) and about 50%, between about 0% and about 45%, between about 0% and about 40%, between about 0% and about 35%, between about 0% and about 30%, between about 0% and about 25%, between about 0% and about 20%, between about 0% and about 15%, between about 0% and about 10%, between about 0% and about 5%, between about 5% and about 50%, and between about 5% and about 45%. Between approximately 5% and approximately 40%, between approximately 5% and approximately 35%, between approximately 5% and approximately 30%, between approximately 5% and approximately 25%, between approximately 5% and approximately 20%, between approximately 5% and approximately 15%, between approximately 5% and approximately 10%, between approximately 10% and approximately 50%, between approximately 10% and approximately 45%, between approximately 10% and approximately 40%, between approximately 10% and approximately 35%, between approximately 10% and approximately 30%, between approximately 10% and approximately 25%, between approximately 10% and approximately 20%, between approximately 10% and approximately 15% Between %, between approximately 15% and approximately 50%, between approximately 15% and approximately 45%, between approximately 15% and approximately 40%, between approximately 15% and approximately 35%, between approximately 15% and approximately 35%, between approximately 15% and approximately 25%, between approximately 15% and approximately 20%, between approximately 20% and approximately 50%, between approximately 20% and approximately 45%, between approximately 20% and approximately 40%, between approximately 20% and approximately 35%, between approximately 20% and approximately 35%, between approximately 20% and approximately 25%, between approximately 25% and approximately 50%. Between approximately 25% and approximately 45%, between approximately 25% and approximately 40%, between approximately 25% and approximately 35%, between approximately 25% and approximately 35%, between approximately 30% and approximately 50%, between approximately 30% and approximately 45%, between approximately 30% and approximately 40%, between approximately 30% and approximately 35%, between approximately 35% and approximately 50%, between approximately 35% and approximately 45%, between approximately 35% and approximately 40%, between approximately 40% and approximately 50%, between approximately 40% and approximately 45%, between approximately 45% and approximately 50%, and combinations thereof.

[0412] In some embodiments with a porosity of less than about 50%, blood cannot perfuse through the sidewalls of the stent 500 at normal vascular pressures (e.g., the pressure drop across the blood vessels, from the afferent to the efferent vessels). In some such embodiments, without (e.g., substantially without, none, essentially none) graft material and without significant or no blood loss through the sidewalls of the stent 500, blood flowing into the proximal end of the stent 500 can be directed through the lumen of the stent 500 to the distal end of the stent 500. In contrast, in some so-called "flow-directing stents," the porosity is specifically designed to be greater than about 50% to ensure perfusion to the efferent vessels.

[0413] The density of the support 500 can be the reciprocal of the porosity (e.g., the outer surface area of ​​the filament 502 divided by the total outer surface area of ​​the support 500). The density of the support 500 can be 100% minus the porosity value provided above.

[0414] The filament 502 is positioned relative to an axis perpendicular to the longitudinal axis of the support 500 (e.g., as in...). Figure 25A A braiding angle 506 is formed (illustrated by dashed lines in the example). The braiding angle 506 can range from just more than 90° to just below 180°. The braiding angle 506 can be an acute or obtuse angle. In some embodiments, the braiding angle 506 is between about 90° and about 180°, between about 120° and about 180°, between about 150° and about 180°, between about 160° and about 180°, between about 170° and about 180°, between about 160° and about 170°, between about 165° and about 175°, combinations thereof, and so on. In some embodiments, the closer the braiding angle 506 is to 180°, the greater the radial strength of the support 500. A device 500 with greater radial strength can help keep a fistula (e.g., formed as described herein) open or unclogged. Other factors can also affect radial strength, such as the diameter of filament 502, the material of filament 502, and the number of filaments 502.

[0415] The filaments 502 can all be identical, or some filaments 502 can have different parameters (e.g., material, size, combination thereof, and so on). In some embodiments, some filaments 502 contain a shape memory material (e.g., containing nitinol), while other filaments 502 contain another material (e.g., containing aramid fibers, e.g., ), Biocompatible polymers, etc. Shape memory materials can provide mechanical structures, while other materials can provide low porosity (e.g., by being thick in the dimensions of the sidewalls).

[0416] Figure 25BThis is a schematic side view of yet another exemplary embodiment of the prosthesis 520. The prosthesis, stent, or device 520 includes a first plurality of filaments 522 woven together to form a first woven structure and a second plurality of filaments 524 woven together to form a second woven structure, and / or is substantially composed of the first plurality of filaments 522 and the second plurality of filaments 524. The stent 520 may be without graft material, as described in further detail herein. The first plurality of filaments 522 may be similar to those described above. Figure 25A The stent 500 is described as having a filament 502. In some embodiments, the filament 522 may lack sufficient radial force to maintain fistula opening and / or attach to the sidewalls of the artery and / or vein. In some such embodiments, the filament 524 may act as a supplementary support structure providing radial force. The filament 524 may be a radially outwardly oriented filament 522 (e.g., as in...). Figure 25B The filaments 524 (illustrated in the diagram), radially inward filaments 522, and / or integrated with filaments 522 (e.g., making the first and second woven structures difficult to separate). The filaments 524 may be made of the same or different material as filaments 522, have the same or different thicknesses, etc., and / or filaments 524 may be woven with the same or different parameters (e.g., weave angle) as filaments 522, resulting in filaments 524 having greater radial force. The filaments 524 may be coupled to filaments 522 (e.g., in a single deployable support 520) or deployed separately. For example, if filament 524 is deployed and then filament 522 is deployed, filament 524 is able to open the fistula and allow filament 522 to expand within the lumen established by filament 524 without substantial reaction force. For another example, if filament 522 is deployed and then filament 524 is deployed, filament 524 is able to act as an expansion force on portions of filament 522 when expansion force is required.

[0417] Despite Figure 25B The diagram is illustrated to include a second woven structure, but the supplementary support structure may additionally or optionally include a helical coil, a cut hypotube, a combination thereof, and the like. The porosity of the prosthesis 520 can be determined primarily based on the porosity of the first woven structure, such that the supplementary support structure can be primarily designed to provide radial force (e.g., sufficient to keep the fistula open or unopen).

[0418] Although illustrated as having a consistent or substantially consistent length across the support 500, the parameters of the support 500 and the filament 502 can vary across the support 500, for example, regarding... Figure 25C The description states that consistency can reduce manufacturing costs, decrease the requirement for precise placement, and / or offer other advantages. Inconsistency can allow for specialization or customization along different lengths for specific properties and / or functions, and / or offer other advantages.

[0419] Figure 25CThis is a schematic side view of yet another example embodiment of the prosthesis 540. The prosthesis, stent, or device 540 includes a plurality of filaments 542 woven together to form a woven structure and / or is substantially composed of said plurality of filaments 542. The stent 540 may be without graft material, as described in further detail herein. The stent 540 includes a first longitudinal segment or section or portion 544 and a second longitudinal segment or section or portion 546. Porosity (e.g., as in...) Figure 25B The parameters of the stent 540, such as the braiding angle, braiding type, filament 542 parameters (e.g., diameter, material, etc.), the presence of supplementary support structures (e.g., supplementary support structure 544), stent diameter, stent shape (e.g., cylindrical, truncated conical), and combinations thereof, can differ between the first longitudinal segment 544 and the second longitudinal segment 546. Porosity can be varied depending on the purpose for which certain portions of the stent 540 are intended. For example, the first longitudinal segment 544, which can be configured for placement in arteries and fistulas, can have low porosity (e.g., less than about 50%, as per the diagram). Figure 25A The stent 500 (described) is designed to increase fluid flow through the stent 500, and a second longitudinal segment that can be configured for placement in a vein may have higher porosity to increase flexibility and wall adhesion.

[0420] In some embodiments, the stent includes a first longitudinal segment, a second longitudinal segment, and a third longitudinal segment. The first longitudinal segment includes a low-porosity fabric configured to divert flow from an artery into a fistula and / or is substantially composed of the low-porosity fabric without supplementary support structures. The second longitudinal segment includes the low-porosity fabric configured to divert blood flow through the fistula and / or is substantially composed of the low-porosity fabric and includes supplementary support structures configured to open the fistula. The third longitudinal segment includes a low-porosity fabric configured to divert flow from the fistula into a vein and / or is substantially composed of the low-porosity fabric. In some such embodiments, the first longitudinal segment may be configured as... Figure 25A The support is 500, and the third longitudinal section can be configured as... Figure 25A 500 or Figure 25C The bracket is 540.

[0421] The difference between the first longitudinal section 544 and the second longitudinal section 546 can be imposed during manufacturing (e.g., due to weaving parameters, shape settings, etc.) and / or on-site (e.g., during deployment and / or after deployment (e.g., by bracket packaging)).

[0422] Other variations between the first longitudinal segment 544 and the second longitudinal segment 546, as described herein (e.g., including laser-cut portions, additional longitudinal segments, etc.), are also possible. In some embodiments, the stent comprises a first longitudinal segment, a second longitudinal segment, and a third longitudinal segment. The first longitudinal segment includes and / or is substantially composed of a low-porosity fabric configured to divert flow from an artery into a fistula. The second longitudinal segment includes and / or is substantially composed of a low-porosity laser-cut portion configured to be placed in the fistula to divert blood through the fistula and / or to open the fistula. The third longitudinal segment includes and / or is substantially composed of a low-porosity fabric configured to divert flow from the fistula into a vein. In some such embodiments, the first longitudinal segment may be configured as... Figure 25A The support is 500, and the third longitudinal section can be configured as... Figure 25A 500 or Figure 25C The bracket is 540.

[0423] Figure 27 An example implementation of the prosthesis 720 is illustrated schematically below. Figure 27 The anatomical structure of the prosthesis 720 is described in further detail. The prosthesis 720 includes a first longitudinal segment 722, a second longitudinal segment 724, and a third longitudinal segment 726 between the first longitudinal segment 722 and the second longitudinal segment 724. For example, due to its low-porosity fabric structure, even when there is a lack of graft material, the porosity of the prosthesis 720 allows fluid to flow substantially through the lumen of the prosthesis 720 without substantially perfusing through the sidewalls.

[0424] In embodiments where the prosthesis 720 is used in a peripheral vascular system, a first longitudinal segment 722 may be described as an arterial segment, a second longitudinal segment 724 may be described as a venous segment, and a third longitudinal segment 726 may be described as a transition segment. The first longitudinal segment 722 is configured to attach to the sidewall of an artery 700 or another body cavity. For example, for some peripheral arteries, the first longitudinal segment 722 may have an expansion diameter between about 2 mm and about 4 mm (e.g., about 3 mm). The second longitudinal segment 724 is configured to attach to the sidewall of a vein 702 or another body cavity. For example, for some peripheral veins, the second longitudinal segment 724 may have an expansion diameter between about 5 mm and about 7 mm (e.g., about 6 mm). In some embodiments, not as in... Figure 27 The general cylindrical shape shown in the figure, the second longitudinal segment 724 and the third longitudinal segment 726 can have the shape of a truncated cone that tapers from a smaller diameter to a larger diameter from the first longitudinal segment 722.

[0425] The length of the prosthesis 720 can be configured or sized to anchor the prosthesis 720 in the artery 700 and / or vein 702 (e.g., sufficiently to prevent or stop longitudinal movement or migration of the prosthesis 720) and span the interstitial tissue T between the artery 700 and vein 702. For example, for some peripheral arteries, the length of the first longitudinal segment 722 in the dilated or deployed state can be between about 20 mm and about 40 mm (e.g., about 30 mm). As another example, for some peripheral veins, the length of the second longitudinal segment 724 in the dilated or deployed state can be between about 10 mm and about 30 mm (e.g., about 20 mm). For yet another example, for some peripheral vascular systems, the length of the third longitudinal segment 726 in the dilated or deployed state can be between about 5 mm and about 15 mm (e.g., about 10 mm). The total length of the prosthesis 720 in the dilated or deployed state can be between about 30 mm and about 100 mm, or between about 45 mm and about 75 mm (e.g., about 60 mm). Although the interstitial tissue T is illustrated as approximately 2 mm thick, other sizes are possible depending on the specific anatomy of the deployment site. Other sizes, such as those of the prosthesis 720, the first longitudinal segment 722, and / or the second longitudinal segment 724, as described herein, are also possible.

[0426] The third longitudinal segment 726 comprises a truncated cone or conical shape that expands from the smaller diameter of the first longitudinal segment 722 to the second longitudinal segment 724. The transition points between longitudinal segments 722, 724, and 726 may be explicit or implicit. For example, a transition segment may be considered to include a portion of the first longitudinal segment 722 and the third longitudinal segment 726, or the third longitudinal segment 726 may be considered to include a cylindrical portion having the same diameter as the first longitudinal segment 722. Longitudinal segments 722, 724, and 726 may differ in shape and size as described above, and / or in other ways (e.g., material, type, etc.). For example, one or more portions may be cylindrical, truncated cone, etc., as in... Figure 12 , Figure 13 and Figure 27 The figures are illustrated and described in this article.

[0427] The first longitudinal segment 722 and / or the third longitudinal segment 726 may contain relatively high radial forces, for example, configured to maintain fistula patency, while the second longitudinal segment 724 may contain relatively low radial forces. In some embodiments, the first longitudinal segment 722 and / or the third longitudinal segment 726 comprise a balloon-expandable stent, a woven stent with a high braid angle, and / or the like. In some embodiments, the second longitudinal segment 724 comprises a self-expanding stent, a woven stent with a low braid angle, and / or the like. Laser-cut stents, woven stents, different cutting patterns, different braiding patterns, and combinations thereof are described in further detail herein. In some embodiments, the longitudinal segments 722, 724, and 726 may be integral or separate. The second longitudinal segment 724 may be relatively flexible, for example, containing relatively low radial forces, which can help the second longitudinal segment 724 flex with the anatomy during the pulsation of blood flow.

[0428] In some embodiments, the second longitudinal segment 724 and / or the third longitudinal segment 726 may contain graft material (e.g., silicone). The graft material may block or prevent blood flow through the sidewalls of the prosthesis 720 and / or may be used to carry medication. For example, depending on the purpose of the graft material, the graft material may or may not block or substantially block the pores of multiple portions of the prosthesis 720.

[0429] The proximal and / or distal ends of the prosthesis 720 can be non-invasive, for example, including end treatment, low braid angle, small filament diameter, combinations thereof, and the like.

[0430] The radial strength or compressive strength of the scaffold, scaffold graft, or first end, second end, intermediate portion, or sub-portion may be between about 0.1 N / mm and about 0.5 N / mm, between about 0.2 N / mm and about 0.5 N / mm, between about 0.3 N / mm and about 0.5 N / mm, between about 0.1 N / mm and about 0.3 N / mm, between about 0.1 N / mm and about 0.2 N / mm, between about 0.2 N / mm and about 0.5 N / mm, between about 0.2 N / mm and about 0.3 N / mm, or between about 0.3 N / mm and about 0.5 N / mm.

[0431] Certain parameter values ​​of the scaffold, scaffold graft, or first end, second end, intermediate portion, or sub-portion may be correlated (e.g., proportional). For example, the ratio of the thickness of the strut or filament to the diameter of the device portion containing the strut or filament may be between about 1:10 and about 1:250, between about 1:25 and about 1:175, or between about 1:50 and about 1:100. As another example, the ratio of the length of the device or portion thereof to the diameter of the device or portion thereof may be between about 1:1 and about 50:1, between about 5:1 and about 25:1, or between about 10:1 and about 20:1.

[0432] Parts of the device may include radiopaque materials. For example, filaments and / or struts of a scaffold, scaffold graft, or a first end, second end, intermediate portion, or sub-part may include titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, combinations thereof, and the like (e.g., at least partially made thereof). As another example, filaments and / or struts of a scaffold, scaffold graft, or part thereof may include materials having a density greater than about 9 g / cm³ (e.g., at least partially made thereof). Individual radiopaque markers may be attached to certain parts of the device. For example, radiopaque markers may be added to the proximal end of the device or its parts (e.g., the proximal part of the intermediate portion, the proximal part of the distal portion), the distal end of the device or its parts (e.g., the distal part of the intermediate portion, the distal part of the proximal portion), and / or other parts. For example, radiopaque markers between the ends of the device may be used to delineate transitions between materials, parts, etc. Radiopaque linearity may vary across the length of the device. For example, the proximal portion may have a first transmissivity linearity (e.g., due to the distal portion material and / or separate markers), and the distal portion may have a second transmissivity linearity different from the first transmissivity linearity (e.g., due to the distal portion material and / or separate markers). Inflatable members such as balloons may be lined with transmissivity fluid. Inflatable members such as balloons may include transmissivity markers coupled to and / or integrated therein (e.g., on the outer surface of the inflatable member).

[0433] In some embodiments, the device comprises a polymer tube and does not provide a support structure. The middle section of such a device can be relatively more flexible than the ends by, for example, reducing the wall thickness of the polymer tube within the middle section.

[0434] When a mesh or other support structure is provided in conjunction with a polymer tube, the support structure can be located around the outside of the tube, within the inner bore of the tube, or embedded in the tube wall. More than one support structure can be provided, in which case each support structure can have a different position relative to the tube.

[0435] One or both ends of the device may include anchoring elements such as hooks, bulges, or barbs configured to grip or hold the inner wall of the blood vessel. In the absence of anchoring elements, the radial force of the expanded ends may be sufficient to grip or hold the inner wall of the blood vessel.

[0436] There is no need for a clearly defined transition between the middle section and the ends. For example, the type of mesh, material, wall thickness, flexibility, etc., can be gradually changed from the ends toward the middle section or from the middle section toward the ends.

[0437] For example, as described with respect to devices 134 and 140, the flexibility of the device can gradually increase as it moves from the end toward the middle portion. The change in flexibility can be due to variations in mesh density (e.g., winding density, window size), tube thickness, or other factors. The flexibility of the device can be uniform or substantially uniform along the entire length of the support structure (e.g., a bracket), or along certain portions of the support structure (e.g., along the entire end, along the entire middle portion, along one end and the middle portion but not along the other end, etc.).

[0438] While the device described herein is particularly well-suited for use as a transvascular shunt in percutaneous procedures, it can be used in many other medical applications. For example, it can be used in angioplasty to treat occluded vessels with tortuous or kinked paths, or where the vessel may be deflected or deformed at or near the stent site. Stents can also be used, for example, during percutaneous procedures, in aortic grafting, or after perforation to repair damaged vessels. In some such cases, in response to vessel movement, the intermediate portion of the device can allow it to conform to and deform the shape of the vessel with a reduced risk of fatigue failure while keeping the ends fixed or anchored in place. As another example, the device can be used to create a shunt between a healthy artery and a healthy vein for dialysis access and / or drug administration (e.g., intermittent infusions for cancer treatments that may damage the vessel).

[0439] Refer again Figure 4 and Figure 7 The occlusive material 251 can be used to help inhibit or prevent reverse arterial blood flow. As will now be described in further detail, other methods and systems can be used to inhibit or prevent reverse arterial blood flow, or, in other words, to inhibit or prevent arterial blood flow currently flowing into a vein from flowing in the vein in the direction of the normal pre-procedure of blood flow, thereby allowing oxygenated blood to bypass downstream tissues such as the feet.

[0440] Without treatment, peripheral vascular disease (PVD) can progress to severe limb ischemia (CLI), characterized by deep, chronic pain, limited options for angiogenesis, and significant tissue loss leading to frequent amputations. CLI is estimated to have an annual incidence of approximately 50–100 per 100,000, and is associated with a mortality rate of up to 20% at 6 months post-onset.

[0441] Interventional radiologists have actively attempted to treat CLI by trying to open chronic total occlusion (CTO) or by bypassing CTO using products such as the Medtronic-Pioneer catheter in the subintimal space. This catheter tunnels a wire into the subintimal space near the CTO and then attempts to access the blood vessel distal to the occlusion. Once the wire is in place, the user can optionally establish a wider access and then place a stent to provide a bypass catheter across the occlusion. If the wire can pass through the occlusion, conventional approaches to treating PAD such as percutaneous transluminal angioplasty (PTA), stenting, and drug-eluting balloon (DEB) can also be used, or optionally, in the treatment of CLI.

[0442] Below are some statistics on CLI issues from the amputee-coalition.org website:

[0443] In the United States, nearly two million people suffer from limb loss.

[0444] Among those who endure limb loss, the primary cause is:

[0445] Vascular disease (54%) (including diabetes and peripheral artery disease (PAD)),

[0446] • Trauma (45%), and

[0447] • Cancer (less than 2%).

[0448] In the United States, approximately 185,000 amputations occur each year.

[0449] In 2007, hospital spending related to amputations totaled over $6.5 billion.

[0450] Survival rates after amputation vary based on many factors. Those who undergo amputation due to vascular diseases (including PAD and diabetes) face reported 30-day mortality rates between 9% and 15%, and long-term survival rates of 60% at 1 year, 42% at 3 years, and 35%–45% at 5 years.

[0451] Nearly half of those who lose a limb due to vascular abnormalities will die within 5 years. This is higher than the 5-year mortality rate experienced by people with colorectal cancer, breast cancer, and prostate cancer.

[0452] Up to 55% of people with diabetes who undergo lower limb amputations will need to have a second leg amputated within 2 to 3 years.

[0453] Since the early 20th century, CLI has been surgically treated with venous arterialization via open limb surgery. Over the years, numerous small-scale clinical trials using this open limb approach have been published, such as the one summarized by Lu et al. in a 2006 meta-analysis entitled "Meta-analysis of the clinical effectiveness of venous arterialization for salvage of critically ischemic limbs," published in the *European Journal of Vascular and Endovascular Surgery*, Vol. 31, pp. 493-499. This article yielded the following results and conclusions:

[0454] ·result:

[0455] A total of 56 studies were selected for the comprehensive review. No randomized controlled trials (RCTs) were established. Seven patient series matching criteria were used to include 228 patients. The full-year foot retention rate was 71% (95% CI: 64%–77%) and the 1-year secondary patency rate was 46% (95% CI: 39%–53%). Most patients who avoided major amputations experienced successful wound healing, rest pain resolution, and no serious complications.

[0456] ·in conclusion:

[0457] Based on limited evidence, venous arterialization was previously considered a viable alternative to major amputation in patients with chronic, severe lower limb ischemia who were "unoperable".

[0458] Among the other conditions described herein, the methods and systems described herein can be used to create arteriovenous (AV) fistulas using minimally invasive endovascular techniques in the below-the-knee (BTK) vascular system. Such methods may be suitable for patients who: (i) have a clinical diagnosis of symptomatic severe limb ischemia (severe ischemic ulcer or symptomatic gangrene) as defined in Rutherford 5 or 6; (ii) have been evaluated by a vascular surgeon and interventionist and determined that surgical or endovascular treatment is not feasible; and / or (iii) have a clear indication for major amputation.

[0459] In some embodiments, the system or kit optionally includes one or more of the following components: a first ultrasound catheter (e.g., an arterial catheter, a transmitting catheter containing a needle, etc.); a second ultrasound catheter (e.g., a venous catheter, a target catheter, etc.); and a prosthesis (e.g., a nitinol stent graft encased in a delivery system (e.g., a 7Fr (approximately 2.3 mm) delivery system)). The system or kit optionally further includes an ultrasound system and a control system (e.g., a computer). Some users may already have a suitable ultrasound system that can be connected to (one or more) ultrasound catheters. The catheters and prostheses described above can be used in this system or kit, and details of other, additional, and / or modified possible components are described below.

[0460] Figure 14A This is a schematic side cross-sectional view of an example embodiment of an ultrasound-emitting catheter 170, which includes a needle 172 (e.g., a first ultrasound catheter, an arterial catheter (e.g., if the needle extends from an artery into a vein), or a venous catheter (e.g., if the needle extends from a vein into an artery)). The catheter 170 is placed into an artery, with the needle 172 retracted within the lumen of the catheter 170. The catheter 170 can be tracked on a guidewire (e.g., a 0.014-inch (approximately 0.36 mm) guidewire) and / or placed in a sheath through an artery (e.g., the femoral artery) and advanced until the point of complete occlusion of the artery (in the tibial artery). The catheter 170 includes a handle 174 comprising a thruster ring 176. Longitudinal or distal advancement of the thruster ring 176 can advance the needle 172 out of the lumen of the catheter 170, out of the artery, and into a vein, as described herein. Other advancement mechanisms for the needle 172 are also possible (e.g., rotary, motorized, etc.). Before, after, and / or during the advance of needle 172, a guidewire (e.g., a 0.014-inch (approximately 0.36 mm) guidewire) can be placed through needle 172 (e.g., as per the description of needle 172). Figure 3 (as described in guide wire 14), and this guide wire may be referred to as a crossing wire.

[0461] Figure 14B It is inside circle 14B Figure 14A An enlarged schematic side cross-sectional view of the distal portion of the ultrasonic transmitting conduit 170. After advance or emission, the needle 172 extends radially outward from the lumen 173 of the conduit 170. In some embodiments, the lumen 173 terminates proximally to the ultrasonic transmitting device 178. The needle 172 may extend along a path aligned with (e.g., parallel to) the path of the directional ultrasonic signal emitted by the ultrasonic transmitting device 178. Figure 14B The lumen 175 is also shown, which can be used to accommodate a guidewire for tracking catheter 170 to a desired location.

[0462] Figure 15A This is a schematic side view of an example implementation of an ultrasound target catheter 180 (e.g., a second ultrasound catheter, an arterial catheter (e.g., if the needle extends from a vein into an artery)) and a venous catheter (e.g., if the needle extends from an artery into a vein). Figure 15B yes Figure 15A Enlarged schematic side cross-sectional view of the ultrasound target catheter 180 within circle 15B. Figure 15C yes Figure 15A An enlarged schematic side cross-sectional view of the ultrasound target catheter 180 within circle 15C. Catheter 180 can be traced on a guidewire (e.g., a 0.014-inch (approximately 0.36 mm) guidewire) and / or placed in a sheath through a vein (e.g., the femoral vein) and advanced until it is near and / or parallel to the distal end of catheter 170 and / or to a point of occlusion in an artery (e.g., in the tibial vein). Catheter 180 includes an ultrasound receiving transducer 182 (e.g., an omnidirectional ultrasound receiving transducer) which can act as a target in the vein for aligning the needle 172 of catheter 170. Catheter 180 can remain in place or remain stationary or substantially stationary while longitudinally rotating or moving catheter 170 to obtain a good or optimal ultrasound signal indicating that the needle 172 is aligned with catheter 180 and in the orientation of catheter 180.

[0463] Catheters 170 and 180 can be connected to and controlled by an ultrasound transceiver that runs transceiver software. As described further in detail herein, catheter 170 includes a flat or designated ultrasound transmitter 178 configured to transmit an ultrasound signal with low angular spread or a tight beam (e.g., small beamwidth) in the direction of the needle 172 path after advancement from the lumen 173 of catheter 170. Catheter 180 includes an omnidirectional (360-degree) ultrasound receiver 182 configured to act as a target for the ultrasound signal emitted by the designated transmitter 178 of catheter 170. Catheter 170 is rotated until a peak ultrasound signal is displayed, indicating that needle 172 is aligned with catheter 180, such that after needle 172 is extended (e.g., by longitudinally advancing the loop 176 of handle 174), needle 172 can exit the artery in which catheter 170 is located, through the interstitial tissue, and into the vein in which catheter 180 is located.

[0464] Figure 16 This is an example implementation of a diagram for detecting catheter alignment, which can be displayed on a display device of an ultrasound system (e.g., a laptop, tablet, smartphone, combination thereof, and the like). Figure 16The diagram illustrates that a signal originating from the transmitting catheter in the artery has been received by the receiving catheter in the vein. The second frequency envelope from the right is the received signal. The distance from the left side of the screen to the leading edge of the second frequency envelope represents the distance between the catheters. The operator can rotate and move the catheter in the artery, for example, until the second envelope is at its maximum, indicating that the catheter is correctly oriented.

[0465] Figure 17 This is a schematic side view of an example embodiment of a prosthesis (e.g., scaffold, scaffold graft) delivery system 190. In some embodiments, the delivery system 190 is a 7Fr (approximately 2.3 mm) delivery system. Figure 18 This is a schematic side view of an example implementation of a prosthesis (e.g., a scaffold, a scaffold graft) 200. Figure 17 In this delivery system 190, the prosthesis (e.g., prosthesis 200, other prostheses described herein, etc.) is located near the distal end 192 of the delivery system 190 in a compressed or coiled state. In some embodiments, prosthesis 200 includes a shape memory scaffold covered with graft material, such as that described above. Once the traverse suture extends from the artery to the vein, the delivery system 190 can be advanced over the traverse suture, for example, as described herein, due to being advanced through the needle 172. Prosthesis 200 can be deployed from the delivery system 190, for example, by squeezing the trigger handle 194 of the delivery system 190, causing the outer sheath to retract proximally and / or advancing the prosthesis 200 distally. Prosthesis 200 can establish a flow path between the artery and vein and through the interstitial tissue. Other types of delivery systems and prostheses are also possible.

[0466] Refer again Figure 17Some non-limiting example dimensions of the delivery system 190 are provided. The travel distance 196 of the trigger handle 194 can, for example, be between about 0.4 inches (about 1 cm) and about 12 inches (about 30 cm), between about 1 inch (about 2.5 cm) and about 8 inches (about 20 cm), or between about 2 inches (about 5 cm) and about 6 inches (about 15 cm) (e.g., about 2 inches (about 5 cm)). In some embodiments, the travel distance 196 of the trigger handle 194 is at least as long as the length of the prosthesis 200 to be deployed (e.g., in the radially expanded state). In some embodiments, a drive mechanism or other mechanism may be employed to reduce the travel distance 196 of the trigger handle 194 to less than the length of the prosthesis 200 to be deployed (e.g., in the radially expanded state). For example, distance 196 can be adjusted based on at least one of the following: the length of the prosthesis 200 to be deployed, the degree of foreshortening of the prosthesis 200 to be deployed, the deployment mechanism (e.g., whether the outer sheath is retracted proximally, whether the prosthesis 200 is pushed forward distally, or both, whether the delivery system 190 includes a drive mechanism, etc.), combinations thereof, and the like. The length 197 of the outer sheath or catheter portion can, for example, be between approximately 40 inches (approximately 1020 mm) and approximately 50 inches (approximately 1270 mm), between approximately 46 inches (approximately 1170 mm) and approximately 47 inches (approximately 1190 mm), or between approximately 46.48 inches (approximately 1180 mm) and approximately 46.7 inches (approximately 1186 mm). The total length 198 of the delivery system 190 from the proximal end to the distal end can be, for example, between about 40 inches (about 1000 mm) and about 60 inches (about 1500 mm). The lengths 197 and 198 can be adjusted, for example, based on at least one of the following: the length of the prosthesis 200 to be deployed, the degree of shortening of the prosthesis 200 to be deployed, the patient's height, the location of the occlusion being treated, combinations thereof, and the like. In some embodiments, separating the trigger handle 194 from the vascular access point, for example, between about 10 cm and about 30 cm (e.g., at least about 20 cm), can advantageously provide the user with easier handling or administration. In some such embodiments, the length 197 can be between about 120 cm and about 130 cm (e.g., for an antegrade approach) or between about 150 cm and about 180 cm (e.g., for a contralateral approach).

[0467] Refer again Figure 18Some non-limiting example dimensions of the prosthesis 200 are provided, depending on the environment, at least in the compression state. The thickness 201 of the structural struts can, for example, be between about 0.05 mm and about 0.5 mm, or between about 0.1 mm and about 0.2 mm (e.g., about 0.143 mm). The spacing 202 between the struts of the structural struts can, for example, be between about 0.005 mm and about 0.05 mm, or between about 0.01 mm and about 0.03 mm (e.g., about 0.025 mm). The thickness 203 of the connecting struts can, for example, be between about 0.05 mm and about 0.5 mm, or between about 0.1 mm and about 0.2 mm (e.g., about 0.133 mm). The longitudinal length 204 of the structural components can, for example, be between about 1 mm and about 5 mm, or between about 2.5 mm and about 3 mm (e.g., about 2.8 mm). The longitudinal length 205 between structural components can be, for example, between about 0.25 mm and about 1 mm, or between about 0.5 mm and about 0.6 mm (e.g., about 0.565 mm). The length 206 of the strut within the structural component (including all portions wound back and forth) can be, for example, between about 25 mm and about 100 mm, or between about 65 mm and about 70 mm (e.g., about 67.62 mm). The total longitudinal length of the prosthesis 200 can be, for example, between about 25 mm and about 150 mm, or between about 50 mm and about 70 mm (e.g., about 62 mm). As described herein, it is possible to include a variety of laser-cut struts, woven struts, and combinations thereof, including various sizes. The struts described herein may include wires or filaments or portions not cut from a thallium tube or plate.

[0468] The proximal and / or distal ends of the prosthesis 200 may optionally include a ring 210. For example, the ring 210 may help anchor the prosthesis 200 in an artery and / or vein. The circumferential width 211 of the ring 210 may, for example, be between about 0.25 mm and about 1 mm, or between about 0.5 mm and about 0.75 mm (e.g., about 0.63 mm). For example, the longitudinal length 212 of the ring 210 may be between about 0.25 mm and about 2 mm, or between about 0.5 mm and about 1 mm (e.g., about 0.785 mm). In some embodiments, the ratio of the total length of the prosthesis 200 to the longitudinal length 212 of the ring 210 may be between about 50:1 and about 100:1 (e.g., about 79:1). The dimensions 211, 212 of the ring 210 may be adjusted, for example, based on at least one of the following: strut thickness, diameter of the prosthesis (e.g., relative to a blood vessel), total length of the prosthesis, material, shape setting properties, combinations thereof, and the like.

[0469] Figure 19This is a schematic side view of another example implementation of the prosthesis 220. The prosthesis 200 may have the shape of the prosthesis 220, for example, in a radially expanded state (e.g., after deployment from the delivery system 190). Figure 19 The illustration shows an example shape of a prosthesis 220 including a first portion 221 and a second portion 225. The first portion 221 has a generally cylindrical or columnar shape with a length 222 (e.g., about 21 mm) between about 15 mm and about 25 mm and a diameter 223 (e.g., about 3.5 mm) between about 2.5 mm and about 5 mm. The second portion 225 has a generally frustoconical or truncated conical shape with a length 226 (e.g., about 41 mm) between about 30 mm and about 50 mm and a maximum diameter 227 between about 4 mm and about 10 mm, between about 4 mm and about 7 mm (e.g., about 5.5 mm), etc. The conical angle of the second portion 225 away from the first portion 221 can be between about 0.02 degrees and about 0.03 degrees (e.g., about 0.024 degrees).

[0470] Further details regarding prostheses that can be used according to the methods and systems described herein are described in U.S. Patent Application No. 13 / 791,185, filed March 8, 2013, which is incorporated herein by reference in its entirety.

[0471] Figures 20A-20H An example implementation of a method for achieving retrograde perfusion is illustrated schematically. This procedure is described in relation to peripheral vascular systems such as the lower leg, but may be adapted to other body cavities (e.g., cardiac, other peripheral, etc.). For clarity, certain steps such as anesthesia, incision details, and suturing may be omitted. In some implementations, the procedure can be performed from vein to artery (e.g., using a venous catheter from below).

[0472] Access to the femoral artery and femoral vein is obtained. For example, using the Seldinger technique, a guide sheath (e.g., 7Fr (approximately 2.3 mm)) is inserted into the femoral artery and a guide sheath (e.g., 6Fr (approximately 2 mm)) into the femoral vein. Guide wires (e.g., 0.014 inches (approximately 0.36 mm), 0.035 inches (approximately 0.89 mm), 0.038 inches (approximately 0.97 mm)) are inserted through the guide sheath in the femoral artery and guided into the distal portion of the diseased artery 300, posterior or anterior to the tibia. A second guide wire (e.g., 0.014 inches (approximately 0.36 mm), 0.035 inches (approximately 0.89 mm), 0.038 inches (approximately 0.97 mm)) or a ligator is inserted through the guide sheath in the femoral vein. In embodiments using a ligator, the third, fourth, etc., guide wires described herein are accurate—even if the numbering may not be consecutive.

[0473] A venous access needle is percutaneously inserted into a target vein, such as the tibial vein (e.g., the proximal tibial vein (PTV)). In some embodiments, the venous access needle can be guided under ultrasound. In some embodiments, a contrast agent can be injected into the saphenous vein toward the foot (retrograde), and then the contrast agent will flow into the PTV. This flow path can be captured using fluorescence examination, thereby enabling the venous access needle to be guided by fluorescence examination without ultrasound or in addition to ultrasound.

[0474] The target vein can be entered proximally and distally (e.g., a few inches or centimeters) below where the launching catheter 310 may be lodged. In some embodiments, the target vein may be in the ankle. Once the vein entry needle is in the vein, a third guidewire (or “second” guidewire, in this case a snare / snare is used instead of a second guidewire) is inserted into the vein entry needle and advanced antegradely into the target vein until the femoral vein. This entry method can advantageously reduce problems caused by retrograde advancement of the wire through the venous valve, which is described in further detail below. For example, a fluorescent examination guide is used to snare the third guidewire and pull it through the femoral vein sheath. The target catheter 320 is inserted into the femoral vein sheath over the already snareed third guidewire. The target catheter 320 is advanced into the venous system over the third guidewire until the target catheter is near the guidewire in the distal portion of the diseased artery posterior or anterior to the tibia and / or parallel to and / or near the occlusion 304, as shown. Figure 20A As shown in the figure.

[0475] In some embodiments, the third guidewire may include an ultrasound receiving transducer (e.g., omnidirectional) mounted to provide a target for the signal emitted by the transmitting catheter 310, or the target catheter 320 may be tracked on the third guidewire. Either of these cases may allow certain techniques to be omitted (e.g., femoral vein entry, introduction of a venous guide sheath, insertion of a second guidewire, antegrade advancement of the third guidewire to the femoral vein, capture of the third guidewire, advancement of the target catheter 320 on the third guidewire).

[0476] In some implementations, ultrasound can be used to directly access the PTV, which allows the target catheter 320 to be placed directly into the PTV, for example, using a small sheath. This can allow certain techniques to be omitted (e.g., femoral vein access, introduction of the venous guide sheath, insertion of the second guidewire, and antegrade advancement of the third guidewire until it reaches the femoral vein).

[0477] In some embodiments, catheter 320 is not an over-the-wire catheter, but includes a guidewire and an ultrasound receiving transducer (e.g., omnidirectional). Catheter 320 may be inserted as a third guidewire, as a second guidewire, or as a guidewire through a small sheath when directly inserted into the PTV.

[0478] Ultrasonic transducers typically include two electrodes, each comprising surfaces separated by vibrating ceramic. The incoming or received ultrasonic signal wave can be coupled to a length-extended type, such as... Figure 21 As shown in the figure. Figure 21 This is a schematic perspective view of an example embodiment of an ultrasonic receiving transducer 350. If the proximal or tip 352 and the distal or bottom 354 of the transducer 350 are conductive and electrically connected to a wire, the transducer can receive ultrasonic signals. In some embodiments, the length 356 of the transducer 350 is between about 0.1 mm and about 0.4 mm (e.g., about 0.25 mm). In some embodiments, the overlap length 358 of the transducer 350 is between about 0.1 mm and about 0.3 mm (about 0.2 mm). In some embodiments, the diameter of the transducer 350 is similar to, substantially similar to, or the same as the guidewire to which it is mounted. In some embodiments, a row or series of laminated materials can enhance the signal receiving capability of the transducer 350.

[0479] In some embodiments, the guide wire including the ultrasonic receiving transducer may include a piezoelectric film (e.g., including plastic) that can enhance the transducer's signal receiving capability. Figure 22 This is a schematic cross-sectional view of another example embodiment of the ultrasonic receiving transducer 360. Figure 22 The ultrasonic receiving transducer 360 shown includes an optional cavity 368. The ultrasonic receiving transducer 360 includes a series of layers 362, 364, and 366. Layer 362 may include a polymer (e.g., polyvinylidene fluoride (PVDF)) layer. Layer 364 may include an inorganic compound (e.g., tungsten carbide) layer. Layer 366 may include a polymer (e.g., polyimide) layer. The thickness of layer 366 may be between about 25 micrometers (μm or micrometer) and about 250 μm (e.g., at least about 50 μm).

[0480] The launching catheter 310 is traced on the guidewire in the femoral and tibial arteries near and proximal to occlusion 304, as... Figure 20B As shown in the diagram. Catheter 310 can be positioned closer to occlusion 304, depending on the suitability of that portion of the anatomical structure for the retrograde perfusion process. In some embodiments, catheter 310 can be positioned distal to the posterior or anterior tibial artery, for example, near catheter 320. In some embodiments, catheter 310 can be positioned within inches or centimeters of the ankle.

[0481] The transmitting catheter 310 emits a directional ultrasound signal. For example... Figure 20CAs indicated by middle arrows 311 and 312, the transmitting catheter 310 is rotated and moved longitudinally until the signal is received by the target catheter 320. Once the signal is received, this indicates alignment, and the extension of the needle from the transmitting catheter 310 will result in successful entry into the vein. The transverse needle 314 is pushed out of the catheter 310, away from the tibial artery 300, and into the tibial vein 302, as shown. Figure 20D As shown in the diagram, the accuracy of placing the transverse needle 314 to form a fistula between the artery 300 and the vein 302 can be confirmed, for example, using contrast agents and fluorescence examination.

[0482] In some implementations, ultrasound signals can be used to determine the distance between artery 300 and vein 302. See again... Figure 16 The distance from the left side of the screen shown in the figure to the leading edge of the second frequency envelope can be used as an indicator of the distance between the conduits.

[0483] Refer again Figure 16 The display device can graphically show the signal alignment peaks to allow the user to determine the alignment position. In some implementations, the signal alignment can change color above or below a threshold, for example, from red to green. In some implementations, for example, an audio signal can be emitted when the alignment signal crosses a threshold, which can allow the user to remain focused on the patient rather than on a substantially continuous monitoring screen.

[0484] In some implementations, the horizontal line on the screen can be moved upwards during the procedure to indicate the maximum signal value or peak value reached at that point. This line may be referred to as "peak hold." If a larger signal value is reached, the horizontal line moves to match that higher value. If no manipulation can raise the peak value above the horizontal line, that can indicate maximum alignment. If the signal peak value drops below the horizontal line by a certain amount, the conduit may have shifted and is no longer properly aligned. Because the alignment level indicated by the horizontal line has previously been reached during the procedure, the user knows that such an alignment level can be achieved through further rotational and / or longitudinal manipulation.

[0485] A fourth guidewire 316 (e.g., 0.014 inches (approximately 0.36 mm)) (or a “third” guidewire, in which case a ligator is used instead of the second guidewire) is placed through the lumen of the transverse needle 314 of the catheter 310 and enters the tibial vein 302 in a retrograde direction toward the foot, as in vein 302. Figure 20E As shown in the diagram. External clamp pressure can be applied above the needle piercing point to reduce flow in artery 300, thereby inhibiting or preventing hematoma formation, and / or congesting the vein to facilitate valve passage. Catheters 310, 320 can be removed, leaving guidewire 316 in the appropriate position, extending from the guide sheath in the femoral artery, through the arterial tree, and into the tibial vein 302.

[0486] In addition to the directional ultrasound technique described herein, certain techniques may be used to pass through the guidewire 316 from the artery 300 to the vein 302.

[0487] In some embodiments, a tourniquet may be applied to the leg, which can increase the diameter of the vein. In some embodiments, an occlusive agent (e.g., as per [reference to...]) is used. Figure 4 and Figure 7 The occlusion balloon (as discussed) can be used to increase the diameter of a vein. For example, venous flow can be reversed, causing the vein to dilate. A larger vein diameter can create a larger target for the transverse needle 314, making it easier to access the vein 300 using the transverse needle 314.

[0488] In some implementations, the PTA balloon can be used in the target vein, and the needle catheter (e.g., Outback, available from Cordis) can be targeted to the PTA balloon under fluorescence examination. A transverse needle 314 can puncture the PTA balloon, and a decrease in PTA balloon pressure confirms proper alignment of the transverse needle 314. The PTA balloon can increase the vein diameter, creating a larger target for the transverse needle 314, making it easier to access the vein 300 using the transverse needle 314. A guidewire 316 can be advanced through the transverse needle 314 and into the PTA balloon.

[0489] In some embodiments, the PTA balloon includes, for example, a mesh (e.g., a woven mesh) embedded in the polymer of the balloon. When a balloon without such a mesh is punctured, the balloon material may rupture and cause an embolus (e.g., a downstream floating balloon mass). The mesh can help limit tearing of the balloon material, which can inhibit or prevent the balloon material from causing an embolus. In some embodiments, a balloon without a mesh can be configured to capture a guidewire after collapse (e.g., by entanglement of the guidewire in a fold of the balloon), regardless of whether a puncture has occurred.

[0490] In some implementations, two PTA balloons, longitudinally spaced along the catheter axis, can be used in the target vein, and the needle catheter can be targeted at one of the PTA balloons. After puncturing one of the PTA balloons via a transverse needle 314, the contrast agent in the well between the PTA balloons can be released because the punctured balloon no longer acts as a dam for the contrast agent. The release of the contrast agent can be monitored using fluorescence examination. The PTA balloons can be on the same catheter or on different catheters.

[0491] In some implementations, two PTA balloons spaced longitudinally along the catheter axis can be used in the target vein, and the needle catheter can be targeted at the space or hole between the PTA balloons. Contrast agent in the hole can be interfered with after puncture through the transverse needle 314. Interference with the contrast agent can be monitored using fluorescence examination. The PTA balloons can be on the same catheter or on different catheters.

[0492] In some embodiments where a PTA balloon can be used in combination with an ultrasound target within a target vein, the PTA balloon catheter includes a PTA balloon and an ultrasound receiving transducer (e.g., omnidirectional). In some such embodiments, the transmitting catheter 310 can be targeted to the PTA balloon and / or the ultrasound receiving transducer under fluorescence examination, as described herein. A transverse needle 314 can puncture the PTA balloon, and a decrease in pressure of the PTA balloon can confirm proper alignment of the transverse needle 314. The PTA balloon can increase the vein diameter, creating a larger target for the transverse needle 314, making it easier to access the vein 300 using the transverse needle 314. A guidewire 316 can be advanced through the transverse needle 314 and into the PTA balloon.

[0493] In some implementations, the LeMaitre device (e.g., UnBalloon) TM A non-occlusive modeling catheter (available from LeMaitre Vascular, Burlington, Massachusetts) can be used in a target vein. In some embodiments, the LeMaitre device can increase the vein diameter. A larger vein diameter can create a larger target for the transverse needle 314, making it easier to access the vein 300 using the transverse needle 314. In some embodiments, the needle 314 can be inserted into the LeMaitre device. In some such embodiments, the LeMaitre device can act as a mesh target for the transverse needle 314 (e.g., comprising a radiopaque material visible under fluorescence examination). The mesh of the LeMaitre device can be radially expanded by advancing the proximal portion of the mesh distally and / or retracting the distal portion of the mesh proximally (e.g., pushing the ends together like an umbrella) and / or by causing the mesh to self-expand (e.g., in embodiments where at least some portions of the mesh comprise a shape memory material). In some implementations, the LeMaitre device can grip the cross-bracing wire to hold it within the target vein as the LeMaitre device approaches.

[0494] In some embodiments, the transmitting catheter 310 may include a first magnet having a first polarity, and the target catheter 320 may include a second magnet having a second polarity. When the magnets are sufficiently close to allow magnetic movement of one or both of the catheters 310, 320, a transverse needle 314 may be advanced to establish a fistula between the artery 300 and the vein 302. In some embodiments, the first magnet may be circumferentially aligned with the transverse needle 314, and / or the transmitting catheter 310 may be magnetically shielded to provide rotational alignment. In some embodiments, the second magnet may be longitudinally relatively thin to provide longitudinal alignment. In some embodiments, the transverse needle 314 and / or guidewire 316 may be magnetically pulled from the artery 300 to the vein 302, or vice versa. Some systems may include both ultrasound guidance and magnetic guidance. For example, ultrasound guidance may be used for initial alignment, while magnetic guidance may be used for precise alignment.

[0495] Refer again Figures 20A-20H The prosthesis delivery system 330, carrying the prosthesis 340, traces along the guidewire 316 through the interstitial space between the artery 300 and the vein 300, and then enters the vein 300, as... Figure 20F As shown in the illustration. In some embodiments, a separate PTA balloon catheter (e.g., about 2 mm) may be traced on guidewire 316 to pre-dilate the fistula between artery 300 and vein 302 before introduction of the prosthesis delivery system 330. The use of the PTA balloon catheter may depend on, for example, the radial strength of the prosthesis 340.

[0496] For example, by operating the trigger handle 194, the prosthesis 340 is used. Figure 17 The prosthesis 340 is deployed from the prosthesis delivery system 330. In some embodiments, for example, if the prosthesis 340 cannot dilate and / or advance, the prosthesis delivery system 330 can be removed and a PTA catheter (e.g., about 2 mm) can be advanced over the guidewire 316 to attempt to dilate or further enlarge the fistula between the artery 300 and the vein 302. The deployment of the prosthesis 340 can then be re-attempted (e.g., by self-dilation, balloon dilation, etc.). In some embodiments, the deployment of the prosthesis 340 can reshape the blood vessel, for example, by dilating the diameter of the blood vessel by at least about 10%, at least about 20%, at least about 30% or more, between about 0% and about 10%, between about 0% and about 20%, between about 0% and about 30% or more. In embodiments where the prosthesis 340 is self-dilatating, the degree of reshaping can vary over time, for example, the prosthesis 340 dilates when the blood vessel dilates or contracts when the blood vessel contracts.

[0497] Once the prosthesis 340 is deployed, such as Figure 20GAs shown, a PTA catheter can be used to widen the fistula. The diameter of the PTA catheter (e.g., about 3 mm to about 6 mm) can be based at least in part on the following selections: the diameter of artery 300, the diameter of vein 302, the composition of interstitial tissue, the characteristics of prosthesis 340, combinations thereof, and so on. In some embodiments, the prosthesis delivery system 330 may include (e.g., proximal or distal to the prosthesis 340) a PTA balloon catheter, which can be used for one, several, or all of the optional PTA balloon catheter techniques described herein. In embodiments where the prosthesis includes a conical portion, the PTA balloon may include a conical portion. Once the prosthesis 340 is in place, the prosthesis delivery system 330 can be removed, as... Figure 20H As shown in the diagram, an AV fistula is thus formed between artery 300 and vein 302. Confirmation of the placement of the various catheters 310, 320, 330, and prosthesis 340 can be made under fluoroscopic examination using contrast agent injection through the entire procedure.

[0498] In some embodiments, markers (e.g., clips, scalpels, scissors, pencils, etc.) may be applied to the skin (e.g., adhered to the skin, placed on top of it, etc.) to approximately mark the location of the fistula formed by the transverse needle 314 between the artery 300 and vein 302 prior to the deployment of the prosthesis 340. In embodiments where the user uses a blood pressure monitor that expands over the fistula to avoid bleeding, the lack of blood flow can make visualization or even estimation of the fistula site difficult, and the markers can provide such identification. In embodiments where the sending and receiving catheters are removed after fistula formation, the crossing point may be difficult for the user to feel or determine, and the markers can provide such identification. If the fistula will be enlarged, the midpoint of the enlargement balloon may preferably be aligned with the midpoint of the fistula (e.g., to increase or maximize the opening through the gap area). In some embodiments, the markers may be visualized under fluorescence examination (e.g., comprising radiopaque materials) to allow the user to see or remember the location of the fistula under fluorescence examination prior to the deployment of the prosthesis 340.

[0499] Once the prosthesis 340 is in place, the obstacle to blood flow through vein 302 and into the foot is the valves in the vein. Manipulating the guidewire through the venous valves can be challenging, for example, because pressure from the artery may not be sufficient to dilate the vein and cause the valves to become incompetent. The applicant has discovered that one or more of a number of techniques, such as PTA catheters, stents (e.g., covered stents, stent grafts, etc.), and valvular knives, can be used to disable or incompetentize the venous valves distal to the AV fistula, as described in further detail below. Disabling the venous valves allows blood to flow retrogradely from the femoral artery, through vein 302, and through the veins to the venules and capillaries distal to the venous circulation to the foot to provide oxygenated blood to the CLI patient's foot.

[0500] In some implementations, a high-pressure PTA balloon catheter can be used to close venous valves insufficiency (e.g., when inflated to greater than about 10 atm (about 1013 kPa)).

[0501] In some embodiments, one or more stents may be placed across one or more venous valves, causing those valves to become incompetent. For example, such stents should have sufficient radial force to keep the valves open. The stent may forcefully rupture the valve. In some embodiments, the stent includes a covering or graft. Certain such embodiments are able to cover venous collateral vessels. In some embodiments, the stent is bare or without a covering or graft. Certain such embodiments can reduce costs. The venous stent may extend along the length of the vein (e.g., its entire length). For example, in some embodiments, the entire length of the PTV is aligned with the covered stent, covering the venous collateral vessels and interfering with the venous valves.

[0502] In some implementations, the venous stent is separate from the fistula prosthesis. A separate venous stent allows for greater flexibility in certain properties (such as size (e.g., length, diameter), material (e.g., with or without covering or graft)) and other properties. Figure 31A An example embodiment of an arteriovenous fistula stent 340, separate from the example embodiment of the venous stent 342, is schematically illustrated. The venous stent 342 may be spaced apart from the fistula stent 340 (e.g., as in...). Figure 31A(As illustrated in the diagram), the venous stent 342 is placed adjacent to, overlaps with, nests with, or is coaxial with the fistula stent 340 (e.g., the distal segment of the fistula stent 340 is at least partially within the proximal segment of the venous stent 342, or the proximal segment of the venous stent 342 is at least partially within the distal segment of the fistula stent 340). In embodiments where the fistula stent 340 and venous stent 342 overlap, the placement of the venous stent 342 firstly allows the proximal end of the venous stent 342 facing the direction of retrograde blood flow to be covered by the fistula stent 340 to reduce or eliminate blood flow interference that may occur due to the distal end of the venous stent 342. In embodiments where the fistula stent 340 and venous stent 342 overlap, the placement of the venous stent 342 secondly allows the fistula stent 340 to pass through the fistula stent 340, such that the two stents 340, 342 can share at least one deployment parameter (e.g., allowing the stent deployment device to be tracked on the same guidewire). The venous stent 342 can be deployed before or after the fistula stent 340. The venous stent 342 may have a length between approximately 2 cm and approximately 30 cm (e.g., approximately 2 cm, approximately 3 cm, approximately 4 cm, approximately 5 cm, approximately 6 cm, approximately 7 cm, approximately 8 cm, approximately 9 cm, approximately 10 cm, approximately 11 cm, approximately 12 cm, approximately 13 cm, approximately 14 cm, approximately 15 cm, approximately 16 cm, approximately 17 cm, approximately 18 cm, approximately 19 cm, approximately 20 cm, approximately 21 cm, approximately 22 cm, approximately 23 cm, approximately 24 cm, approximately 25 cm, approximately 26 cm, approximately 27 cm, approximately 28 cm, approximately 29 cm, approximately 30 cm, and ranges between such values, etc.).

[0503] In some implementations, the venous stent is integrated with the fistula prosthesis. An integrated venous stent allows for greater flexibility in certain properties (such as size (e.g., length, diameter), materials (e.g., with or without coverings or grafts)) and other properties. Figure 31B An example embodiment of an arteriovenous fistula stent 344, which includes an integrated venous stent, is illustrated schematically. Figure 31C An example embodiment of a fistula stent 344 comprising an integrated venous stent is schematically illustrated. The stent 344 includes a first portion 346 configured to be anchored in an artery, a second portion 350 configured to be anchored in a vein and lining a length of vein, and a third portion 348 longitudinally located between the first portion 346 and the second portion 350. In embodiments where the first portion 346 and the second portion 350 have different diameters (e.g., as in...), Figure 31C(As illustrated in the diagram), the third portion 348 may be tapered. In some embodiments, a portion of the second portion 350 configured as a lining vein has properties different from other portions of the second portion 350 (e.g., diameter, material, radial strength, combinations thereof, and the like). The length of the second segment 350 may be greater than the length of the first segment 346. For example, the second segment 350 may have the length configured as a lining vessel (such as a PTV). The second segment 350 may have a length between approximately 2 cm and approximately 30 cm (e.g., approximately 2 cm, approximately 3 cm, approximately 4 cm, approximately 5 cm, approximately 6 cm, approximately 7 cm, approximately 8 cm, approximately 9 cm, approximately 10 cm, approximately 11 cm, approximately 12 cm, approximately 13 cm, approximately 14 cm, approximately 15 cm, approximately 16 cm, approximately 17 cm, approximately 18 cm, approximately 19 cm, approximately 20 cm, approximately 21 cm, approximately 22 cm, approximately 23 cm, approximately 24 cm, approximately 25 cm, approximately 26 cm, approximately 27 cm, approximately 28 cm, approximately 29 cm, approximately 30 cm, and a range between such values, etc.).

[0504] In some in situ bypass procedures, the saphenous vein is attached to an artery in the thigh and another in the calf, bypassing any blockages in the arteries. In some such procedures, the vein is not stripped from the patient, flipped longitudinally, and used as a prosthesis, but left in place so that blood flow is retrograde (for the vein's valves). A standard valve knife can be inserted into the saphenous vein from below and advanced to the top in a collapsed state, opened, and then pulled back in an open state, cutting along the path of the venous valves. The cutting surface of this valve knife faces backward, thus cutting during retraction during these procedures. Figure 23A This is a schematic perspective view of an example embodiment of a valve knife 400, which can be used with a procedure including a proximal blade 402.

[0505] In some implementations of the method described herein, the distal inlet to the venous valve is unavailable, making it impossible to pull the valve knife backward, but it is possible to push the reverse valve knife forward as described herein. Figure 23BThis is a schematic perspective view of an example embodiment of a valve knife 410 that can be used with such a procedure. The reverse valve knife 410 includes one or more blades 412 (e.g., 2-5 blades, e.g., 3 blades) facing anteriorly or distally, so that the valve can be cut as the reverse valve knife 410 is advanced distally. At least because retrograde access to the vein to be decompensated was not previously considered a problem, there is no a priori motivation to reverse the direction of the valve knife blades to form a reverse valve knife 410 as described herein. The reverse valve knife 410 can be tracked on a guidewire 414, which can be manipulated into the vein to cause venous valve insufficiency. As described herein, after a fistula is formed between an artery and a vein, the fluid flow in the vein is in the opposite direction to the natural, normal, or pre-procedural direction of the fluid flow in the vein, so that the reverse valve knife 410 is pushed in the opposite direction to the natural fluid flow but in the direction of the post-fistula fluid flow.

[0506] Other systems and methods can also be used to close valves in veins (e.g., cutting balloons, atherectomy, laser ablation, ultrasound ablation, heating, radiofrequency (RF) ablation, catheters with traumatic or non-traumatic tips that are being advanced and / or retracted (e.g., guide sheaths), combinations thereof, and the like).

[0507] Passing through the venous valve retrogradely before causing such valve insufficiency can also be challenging. Figure 24 This is a schematic perspective view of an example embodiment of the LeMaitre device 420, which can be used to radially dilate veins and thus their valves. The LeMaitre device 420 includes an expandable elliptical or elongated leaf-shaped 422, such as a self-expanding nitinol mesh. In some embodiments, a PTA balloon catheter can be used to radially dilate veins and thus their valves. In some embodiments, applying a tourniquet to the leg can radially dilate veins and thus their valves. After radial dilation, a guidewire can be advanced through (one or more) extended valves (e.g., via dilation devices such as the LeMaitre device) and catheters (e.g., PTA, stent delivery, percutaneous excision (e.g., orientation, orbital, laser, etc.)) or other over-the-wire devices can be advanced over the guidewire.

[0508] Figure 26A and 26B Another example implementation of the method for achieving retrograde perfusion is illustrated schematically. (Refer again) Figure 20EA fistula can be established between an artery 600 and a vein 602, including an occlusion 604, using one or more of the techniques described herein and / or other techniques, by means of a guidewire 606 extending therein. A prosthesis delivery system carrying a prosthesis 620 traces along the guidewire 606 through the interstitial region between the artery 600 and the vein 602 and enters the vein 602, as in Figure 26A As shown in the diagram. In some embodiments, a separate PTA balloon catheter (e.g., about 2 mm) is capable of being traced on guidewire 606 to pre-dilate the fistula between artery 600 and vein 602 prior to the introduction of the prosthesis delivery system. The use of the PTA balloon catheter may depend on, for example, the radial strength of the prosthesis 620. The prosthesis 620 may be... Figures 25A-25C The stents 500, 520, 540 or variations thereof (e.g., as per [reference]). Figure 25C (As described), the stent comprises uncovered, low-porosity woven filaments configured to divert blood flow.

[0509] The flow redirection properties of uncovered fibrous threads can depend on certain hemodynamic characteristics of the vascular lumen. For example, if the occlusion 604 is incomplete, allowing some pressure drop to occur between the lumen of prosthesis 620 and the portion of artery 600 between occlusion 604 and prosthesis 620, blood may be able to flow through the sidewall of prosthesis 620 instead of into the fistula. See again... Figure 4 As described with respect to occlusion material 251, occlusion material 608 may optionally be provided in artery 600 to further occlude artery 600, which is capable of preventing hydrodynamic effects that could cause and / or allow blood to flow through the sidewalls of prosthesis 620. For another example, a pressure drop between artery 600 and vein 602 can cause and / or allow blood to flow through the sidewalls of the prosthesis in the normal direction of venous blood flow rather than through the lumen of the prosthesis to achieve retrograde perfusion. See again Figure 4 As described in the description of occlusion material 251, occlusion material 610 may optionally be provided in vein 602, thereby occluding the portion of vein 602 downstream of the fistula under normal venous flow, which is able to prevent hydrodynamic effects that may cause and / or allow blood to flow through the sidewalls of prosthesis 620.

[0510] For example, by operating the trigger handle 194 ( Figure 17The prosthesis 620 is deployed from the prosthesis delivery system. In some embodiments, for example, if the prosthesis 620 cannot dilate and / or advance, the prosthesis delivery system can be removed, and a PTA catheter (e.g., about 2 mm) is advanced over the guidewire 620 to attempt to dilate or further dilate the fistula between artery 600 and vein 602. The deployment of the prosthesis 620 can then be retried (e.g., by self-dilation, balloon dilation, etc.). In some embodiments, the deployment of the prosthesis 620 can reshape the blood vessel, such as by dilating the diameter of the blood vessel as described herein. In embodiments where the prosthesis 620 is self-dilatating, the degree of reshaping can vary over time, for example, the prosthesis 620 dilates when the blood vessel dilates or contracts when the blood vessel contracts. The prosthesis 620 can conform to the anatomical structure in which the prosthesis 620 is deployed. For example, in an expanded state on an operating table or tabletop, the prosthesis 620 can be generally cylindrical, but the prosthesis 620 can conform to the diameter of the vessel and fistula, wherein the prosthesis 620 is deployed in the vessel and fistula such that the prosthesis can have different diameters, tapers, non-cylindrical shapes, combinations thereof, and so on in different longitudinal segments.

[0511] The prosthesis 620 includes supplementary support structures (e.g., as per [reference]). Figure 25B In some implementations described, the deployment of the prosthesis may include deploying a first weave structure and deploying a supplementary support structure before, during, and / or after the deployment of the first weave structure.

[0512] The fistula may optionally be enlarged using a PTA catheter before, during, and / or after the deployment of the prosthesis 620. The diameter of the PTA catheter (e.g., from about 3 mm to about 6 mm) may be selected based at least in part on the diameter of the artery 600, the diameter of the vein 602, the composition of the interstitial tissue, the characteristics of the prosthesis 620, their combination, and so on.

[0513] Once the prosthesis 620 is in place, the prosthesis delivery system can be removed, as in... Figure 26B As shown in the diagram, an AV fistula is thus formed between artery 600 and vein 602. Even in the absence of prosthesis or graft material, blood flows through the lumen of prosthesis 620 due to the hemodynamic effects of low porosity (e.g., less than about 50% porosity or other values ​​described herein). Figure 26B An embodiment where the occlusion materials 608 and 610 are not used is shown. Once the prosthesis 620 is in place, venous valve insufficiency can be closureed, for example as described herein.

[0514] The prosthesis 620 contains two sets of multiple filaments that can be deployed individually (e.g., as per [reference]). Figure 25BIn some embodiments described herein, multiple filaments may be deployed at least partial...

Claims

1. An apparatus for diverting blood flow from a first blood vessel to a second blood vessel while maintaining blood flow in the first blood vessel, the apparatus comprising: A scaffold structure extending along a length from proximal to distal and having a repeating circumferential unit structure along the length, the scaffold structure including a ring, wherein the scaffold structure is embedded in a graft, and wherein the scaffold structure comprises: A first segment, extending from the proximal end and configured to anchor in the first vessel, wherein the first vessel comprises an artery, wherein the first segment is configured to receive blood flow through the proximal end, and wherein the first segment includes a window configured to allow a first portion of the blood flow to enter the first segment, flow through the window, and flow distally out of the first segment into the first vessel, thereby maintaining blood flow in the first vessel; and A second segment, extending from the distal end and configured to be positioned within the second vessel, wherein the second vessel comprises a vein, and wherein the second segment is configured to receive a second portion of the blood flow from the first segment and to deliver the second portion of the blood flow through the second segment. And flow distally out of the distal end into the second vascular duct; and The third segment, positioned between the first segment and the second segment, wherein, when the support structure is in an expanded state: The first segment has a first diameter adjacent to the third segment. The second segment has a second diameter that is larger than the first diameter and is adjacent to the third segment. The third segment has a third diameter that is tapered from the first diameter to the second diameter.

2. The apparatus of claim 1, wherein the window is formed during the manufacturing process.

3. The apparatus of claim 1, wherein the window is formed in situ.

4. The apparatus of claim 3, wherein a portion of the graft along the first segment can be punctured to form the window.

5. The apparatus of claim 1, wherein the first segment includes a wing configured to open radially outward to allow the first portion of the blood flow in the first segment to flow through the window.

6. The apparatus of claim 1, wherein the first segment includes a plurality of slits configured to open and form the window when the first segment bends.

7. An apparatus for diverting blood flow from a first blood vessel to a second blood vessel while maintaining blood flow in the first blood vessel, the apparatus comprising: A scaffold structure extending along a length from proximal to distal and having a repeating circumferential unit structure along the length, wherein the scaffold structure is embedded in a graft, and wherein the scaffold structure comprises: A first segment extends from the proximal end and is configured to anchor in the first vessel, wherein the first vessel includes an artery, wherein the first segment is configured to receive blood flow through the proximal end, and wherein the first segment includes a window configured to allow a first portion of the blood flow to enter the first segment, flow through the window, and flow distally out of the first segment into the first vessel, thereby maintaining blood flow in the first vessel; A second segment, comprising a second portion of the stent structure and extending distally therefrom and configured to be positioned within a second vessel, wherein the second vessel comprises a vein, and wherein the second segment is configured to receive a second portion of the blood flow from the first segment, and to deliver the second portion of the blood flow through the second segment and flow distally out of the distal end into the second vessel; and The third segment, positioned between the first segment and the second segment, wherein, when the support structure is in an expanded state: The first segment has a first diameter adjacent to the third segment. The second segment has a second diameter that is larger than the first diameter and is adjacent to the third segment. The third segment has a third diameter that is tapered from the first diameter to the second diameter.

8. The apparatus of claim 7, wherein the window is formed during the manufacturing process.

9. The apparatus of claim 7, wherein the window is formed in situ.

10. The apparatus of claim 9, wherein a portion of the first segment is puncturable to form the window.

11. The device of claim 7, wherein the first segment includes a wing configured to open radially outward to allow blood flow through the window.

12. The apparatus of claim 7, wherein the first segment includes a plurality of slits configured to open and form the window when the first segment bends.

13. An apparatus for diverting blood flow from a first blood vessel to a second blood vessel while maintaining blood flow in the first blood vessel, the apparatus comprising: A scaffold structure extending along a length from proximal to distal, the scaffold structure being embedded in a graft, and wherein the scaffold structure comprises: A first segment, the first segment extending from the proximal end and configured to anchor in the first vessel, the first segment being configured to allow a first portion of the blood flow to enter the first segment, and to flow distally out of the first segment into the first vessel, thereby maintaining blood flow in the first vessel; A second segment, extending from the distal end and configured to be positioned within the second vessel, wherein the second segment is configured to receive a second portion of the blood flow from the first segment, and to deliver the second portion of the blood flow through the second segment and flow distally out of the distal end into the second vessel; and The third segment, positioned between the first segment and the second segment, wherein, when the support structure is in an expanded state: The first segment has a first diameter adjacent to the third segment. The second segment has a second diameter that is larger than the first diameter and is adjacent to the third segment. The third segment has a third diameter that is tapered from the first diameter to the second diameter.

14. The apparatus of claim 13, wherein the window is formed during the manufacturing process.

15. The apparatus of claim 13, wherein the window is formed in situ.

16. The apparatus of claim 15, wherein a portion of the graft along the first segment is puncturable to form the window.

17. The apparatus of claim 13, wherein the first segment includes a wing configured to open radially outward to allow the first portion of the blood flow in the first segment to flow through a window.

18. The apparatus of claim 13, wherein the first segment includes a plurality of slits configured to open and form a window when the first segment bends.

19. The device of claim 13, wherein the support structure includes a ring along the length.

20. The apparatus of claim 13, wherein the first segment further includes a branch configured to be positioned in a branch vessel of the first vessel.

21. An apparatus for diverting blood flow from a first vessel to a second vessel and maintaining blood flow in the first vessel, the apparatus comprising: A first segment, configured to be anchored in the first blood vessel, wherein the first segment includes a window to allow a first portion of the blood flow to enter the first segment, through the window, and distally into the first blood vessel, thereby maintaining blood flow in the first blood vessel; The second segment is configured to be anchored in the second vessel, wherein the second segment is configured to receive a second portion of the blood flow from the first segment and to deliver the second portion of the blood flow through the second segment and distally into the second vessel; and A third segment, positioned between the first segment and the second segment, wherein the first segment has a first diameter adjacent to the third segment. The second segment has a second diameter that is larger than the first diameter and is adjacent to the third segment. The third segment has a third diameter that is tapered from the first diameter to the second diameter.

22. The apparatus of claim 21, wherein the window is formed during the manufacturing process.

23. The apparatus of claim 21, wherein the window is formed in situ.

24. The apparatus of claim 23, wherein the first segment comprises a puncturable graft.

25. The apparatus of claim 23, wherein the first segment includes a stent structure configured to facilitate puncture.

26. The apparatus of claim 21, wherein the first segment includes a wing configured to open radially outward.

27. The apparatus of claim 21, wherein the first segment comprises a plurality of blades configured to open radially outward.

28. The apparatus of claim 21, wherein the first segment can be deployed separately from the second segment.

29. The apparatus of claim 21, wherein the first segment includes a branch configured to be positioned in a branch vessel of the first vessel.

30. The apparatus of claim 21, wherein the first segment includes a plurality of slits configured to open when the first segment bends.

31. The apparatus according to any one of claims 21 to 30, wherein the first segment comprises a support structure, at least a portion of which is uncovered.

32. The apparatus of claim 31, wherein the second segment comprises the support structure.

33. The apparatus of claim 32, wherein at least one parameter of the support structure is different between the first segment and the second segment.

34. The apparatus of claim 33, wherein the parameters include a unit pattern.

35. The apparatus according to any one of claims 21 to 30, wherein the second segment comprises a graft cover.

36. The apparatus of claim 35, wherein the graft covering is substantially perpendicular to the longitudinal axis of the apparatus.

37. The apparatus of claim 35, wherein the graft covering is at an angle to the longitudinal axis of the apparatus.

38. The apparatus of claim 37, wherein the angle is between 10° and 70°.

39. The apparatus according to any one of claims 21 to 30, wherein the first segment comprises a graft cover.

40. The apparatus of claim 39, wherein the graft covering of the first segment includes a V-shaped incision.

41. The device according to any one of claims 21 to 30, further comprising an occlusive implant.

42. The device of claim 41, wherein the occlusion implant includes a tether configured to be anchored in the second segment.

43. The apparatus according to any one of claims 21 to 30, wherein the second segment includes a third segment configured to restrict fluid flow through the apparatus.

44. The apparatus of claim 43, wherein the third segment has a narrower diameter than the second segment.

45. The apparatus according to any one of claims 21 to 30, wherein the first segment includes a flange.

46. ​​The device according to any one of claims 21 to 30, wherein the device comprises a woven fabric having variable porosity along its length, the first segment comprising a portion having a first porosity configured to allow blood perfusion through the portion, and the second segment comprising a portion having a second porosity configured to deflect blood through the portion.

47. The apparatus of claim 46, wherein the first porosity is less than 75%.

48. The apparatus of claim 46, wherein the second porosity is greater than 60%.

49. The apparatus according to any one of claims 21 to 30, wherein the first segment comprises a plurality of wires woven together to form a mesh structure having an expansion diameter between 4 mm and 8 mm, a porosity between 60% and 75%, a length between 50 mm and 150 mm, a weaving angle between 120° and 179°, and a compression resistance between 0.4 N / mm and 1.1 N / mm.

50. The apparatus of any one of claims 21 to 30, wherein the first segment is configured to overlap with a stent graft stretching the first vascular vessel, and wherein the apparatus is configured to stretch the first vascular vessel in a conical manner to provide laminar flow through the apparatus.

51. The apparatus according to any one of claims 21 to 30, wherein the apparatus comprises: The fourth segment is tapered from the first diameter to the third diameter; as well as The fifth segment is tapered from the third diameter to the second diameter.

52. The apparatus according to any one of claims 21 to 30, wherein the apparatus comprises: The fourth segment is tapered from the third diameter to the second diameter.

53. A method of forming a window in the apparatus of any one of claims 23 to 25, the method comprising: The device is implanted into the first blood vessel, extends through the interstitial tissue, and enters the second blood vessel; as well as A guidewire is inserted into the bend of the device through the first blood vessel, and the guidewire punctures the graft material to form an opening.

54. The method of claim 53, further comprising tracking the dilator on the guidewire to widen the opening.

55. The method of claim 53, further comprising: The balloon is tracked on the guidewire, and the balloon extends through the opening; as well as The balloon is inflated, and the inflated balloon enlarges the opening.

56. The method of claim 53, further comprising positioning a radiopaque target in the first vascular duct outside the device and downstream of the device.

57. The method of claim 53, further comprising deploying a support through the opening.

58. An apparatus for diverting blood flow from a first vessel to a second vessel and maintaining blood flow in the first vessel, the apparatus comprising: A first segment, configured to be anchored in the first vessel, the first segment comprising: Support structure; A window, said window allowing blood to flow into the first segment, through said window, and distally within the first blood vessel; and Flange; A second segment, configured to be anchored in the second vessel, configured to allow blood to flow into the first segment, through the second segment, and into the second vessel, the second segment comprising: Support structure; and graft coverings; and The third segment, positioned between the first segment and the second segment, wherein, when the support structure is in an expanded state: The first segment has a first diameter adjacent to the third segment. The second segment has a second diameter that is larger than the first diameter and is adjacent to the third segment. The third segment has a third diameter that is tapered from the first diameter to the second diameter.

59. The apparatus of claim 58, wherein the window is formed during the manufacturing process.

60. The apparatus of claim 58, wherein the window is formed in situ.

61. The apparatus of claim 58, wherein a portion of the graft along the first segment is puncturable to form the window.

62. The apparatus of claim 58, wherein the first segment includes a wing configured to open radially outward to allow blood flow through the window.

63. The apparatus of claim 58, wherein the first segment includes a plurality of slits configured to open and form the window when the first segment bends.

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