Catheter alignment device and method

Abstract

To provide a method and a system for improving a transdermal method and a transdermal system.SOLUTION: A launching catheter for targeting a second vessel from a first vessel includes a catheter 4206 including a proximal portion and a distal portion 4204 including a needle opening and a flat, rectangular radiopaque marker 4210. The flat rectangular radiopaque marker disappears under fluoroscopy upon rotation and provides information about the rotational alignment of the launching catheter. The launching catheter includes a needle configured to extend through the needle opening. A method of registering the catheter includes rotating the catheter within the first blood vessel until the marker has a thickness (e.g., a minimum thickness) under fluoroscopy. The thickness 4234 indicates the rotational alignment of the catheter.SELECTED DRAWING: Figure 42B

Description

TECHNICAL FIELD

[0001] The present application relates to methods and systems used in percutaneous intervention procedures. In particular, the present application relates to methods and systems for providing or maintaining fluid flow through body passages such as heart chambers and blood vessels.

[0002] INCORPORATION BY REFERENCE This application claims the benefit of priority from U.S. Provisional Patent Application No. 62 / 743,107 filed on October 9, 2018, U.S. Provisional Patent Application No. 62 / 817,217 filed on March 12, 2019, and U.S. Provisional Patent Application No. 62 / 887,274 filed on August 15, 2019. Each of these applications is hereby incorporated by reference in its entirety into the present specification. BACKGROUND ART

[0003] Minimally invasive percutaneous surgery, or "keyhole" surgery, is a surgical procedure in which a surgical device is inserted into a patient's body cavity through a small opening incised in the skin. This form of surgery has become increasingly popular because it retains the advantages of conventional surgery while allowing patients to endure less surgical discomfort. Patients treated with such surgical procedures experience less discomfort, have reduced need for general anesthesia, lower risk of trauma and infection, and can have significantly shorter recovery time compared with conventional surgical procedures.

[0004] Keyhole surgery, for example, can be used in laparoscopic surgery to treat cardiovascular diseases. When treating cardiovascular diseases, balloon angioplasty, in which a balloon catheter is usually inserted into an artery near the patient's groin and guided to the patient's heart, where the balloon at the distal end of the catheter inflates, widening the occluded vessel and helping to return blood flow to the cardiac tissue, can be used as an alternative to open-heart surgery to treat partially occluded coronary arteries. A tubular support device (e.g., a stent) can be deployed at the occlusion site to prevent subsequent occlusion (restenosis) or collapse of the vessel. The stent may be, for example, an expandable metal mesh tube supported on the balloon of a balloon catheter, or it may be self-expanding. A balloon-expandable stent expands when the balloon inflates, thereby pressing the stent against the wall of the vessel. When the stent reaches its expanded position, it is configured to maintain its expanded shape by, for example, plastic deformation or a mechanical locking mechanism to form an elastic scaffold or elastic support within the vessel. Support structures (e.g., stents) support the walls of blood vessels and expand them to maintain the pathway for blood flow through the vessels. Self-expanding stents are also available, which are held in a compressed state by a catheter suitably adapted for delivery through arteries and expand when deployed at the site of occlusion. The catheter may have, for example, a retaining sleeve that holds the stent in a compressed, or non-expanded, state. When the sleeve is removed from the stent, the stent expands to support and expand the wall of the blood vessel.

[0005] For example, in acute cases and when the coronary arteries are completely occluded, balloon angioplasty is not always the appropriate measure. In these cases, the usual treatment is coronary artery bypass surgery. Coronary artery bypass surgery is an open-heart or open-chest procedure and usually involves grafting a portion of a healthy vessel onto the coronary artery to bypass the occluded portion and restore blood flow to the coronary artery tissue. The healthy vessel is usually a vein removed from the patient's leg or arm during the bypass surgery. Performing the procedure requires opening the chest, separating the sternum, and incising the pericardium surrounding the heart, which results in significant surgical trauma as the patient's heart must be exposed.

[0006] Conventional coronary artery bypass surgery is not always voluntary. Some patients are unsuitable candidates for conventional coronary artery bypass surgery due to a low prognosis or high risk of significant trauma resulting from the surgery, a high risk of infection, lack of healthy vessels to use as bypass grafts, significant comorbidities, and the expected long and complicated recovery time associated with open-heart surgery. For example, factors such as diabetes, old age, obesity, and smoking may exclude some candidate patients who truly need such treatment. [Overview of the project]

[0007] This application provides methods and systems that overcome several shortcomings and / or improve percutaneous methods and systems. For example, according to some embodiments, the methods and systems described herein can improve the targeting and localization of therapy administration and are advantageous in that they allow percutaneous treatment to be performed on patients who are unsuitable for more invasive surgery. Some embodiments described herein can provide fluid flow in passages such as coronary and / or peripheral blood vessels by creating bypasses using minimally invasive percutaneous surgical methods.

[0008] In some examples, a launch catheter for targeting a second vessel from a first vessel includes a catheter comprising a proximal portion and a distal portion containing a flat radiopaque marker. The radiopaque marker may be rectangular. The catheter may include a needle opening. The catheter may comprise a needle configured to extend through the needle opening.

[0009] The distal portion of the catheter may be curved. The marker does not have to follow the curvature of the distal portion of the catheter. The needle opening may be proximal to the marker. The needle opening may be distal to the marker. The needle opening may at least partially overlap the marker.

[0010] The needle opening may be on the first side of the distal portion of the catheter. The marker may be on the second side of the distal portion of the catheter. The first side may be the same as the second side. The first side may be on the opposite side of the second side. The distal end of the needle extending from the needle opening can be longitudinally aligned with the radiopaque marker. The needle may include a profile. The needle may be able to slide through the needle lumen. The needle lumen may have a shape complementary to the profile (for example, to reduce longitudinal movement of the needle during its advance).

[0011] The marker may include a first radiolucent material and a second radiopaque material bonded to the first radiolucent material. The second radiopaque material can be bonded to the first radiolucent material by one or more of the following methods: cladding, plating, chemical vapor deposition, atomic layer deposition, screen printing, coating, bonding, or sputtering. After being bonded to the first radiolucent material, the second radiopaque material can be polished or planarized.

[0012] The ratio of the marker's length to its width may be between 1 / 1 and 5 / 1.

[0013] The marker may have a thickness of 0.001 mm to 1 mm. The marker may also have a thickness of 1 nm to 10 μm.

[0014] The kit may include a launch catheter and a target catheter. The target catheter may include an expandable member. The expandable member may include a snare. The expandable member may include a mesh. The expandable member may include a radiopaque material. The target catheter may include a first radiopaque marker. The target catheter may include a second radiopaque marker longitudinally spaced from the first radiopaque marker.

[0015] In some examples, a launch catheter for targeting a second vessel from a first vessel includes a catheter comprising a proximal portion and a distal portion containing a needle opening and a flat rectangular radiopaque marker. The flat rectangular radiopaque marker disappears under fluoroscopy upon rotation, providing information regarding the rotational alignment of the launch catheter. The launch catheter further includes a needle configured to extend through the needle opening.

[0016] In some examples, the catheter includes a flat radiopaque marker. The catheter can be a launch catheter for targeting a second vessel from a first vessel. The catheter may include a distal portion containing a flat radiopaque marker. The radiopaque marker may be rectangular. The catheter may include a needle opening. The catheter may have a needle configured to extend through the needle opening. The distal portion of the catheter may be curved. The marker may not follow the curvature of the distal portion of the catheter. The needle opening may be proximal to the marker. The needle opening may be distal to the marker. The needle opening may at least partially overlap the marker. The needle opening 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 the same as the second side. The first side may be opposite to the second side. The distal end of the needle extending from the needle opening can be longitudinally aligned with the radiopaque marker. The needle may include a profile. The needle may be able to slide through the needle lumen. The needle lumen may have a shape complementary to the profile (for example, to reduce longitudinal movement of the needle during its advance). The kit may include a launch catheter and a target catheter. The target catheter may include an expandable component. The expandable component may include a snare. The expandable component may include a mesh. The expandable component may include a radiopaque material. The target catheter may include a first radiopaque marker. The target catheter may include a second radiopaque marker longitudinally spaced from the first radiopaque marker.

[0017] In some examples, the method of aligning the catheter involves rotating the catheter within a first blood vessel. The catheter contains a flat radiopaque marker. The rotation is performed until the marker reaches a thickness that indicates the rotational alignment of the catheter. The thickness can be observed under fluoroscopy. The thickness can be less than a certain value. The thickness can be indicated by a thin (e.g., minimum thickness) line. The radiopaque marker can be rectangular.

[0018] This method may include rotating the catheter within a first blood vessel until the marker has a thickness (e.g., minimum thickness) under fluoroscopy and strikes the side of the catheter. This method may further include advancing the catheter longitudinally until the marker is in close proximity to a second catheter within a second blood vessel. The second catheter may include radiopaque features visible under fluoroscopy. Radiopaque features of the second catheter visible under fluoroscopy may include expandable members. The expandable members may include snares. The expandable members may include mesh.

[0019] This method may further include rotating the catheter and then extending the needle from the catheter. Extending the needle from the catheter may include exiting a first blood vessel and entering a second blood vessel distinct from the first. Catheter alignment may include needle alignment. Extending the needle from the catheter may include traversing the interstitial tissue between the first and second blood vessels.

[0020] This method may further include extending a guidewire through a needle into a second blood vessel. This method may further include entangling the guidewire with a second catheter in the second blood vessel. Entangling the guidewire may include occluding an expandable portion of the second catheter. This method may further include moving the second catheter to detect the corresponding movement of the guidewire. This method may further include moving the second catheter to move the guidewire through the second blood vessel.

[0021] The catheter system may include a tubular body and at least one of the tubular body, an expandable member, or a targeting system coupled to a fluid injection port.

[0022] In some embodiments, a catheter system for identifying branches within a blood vessel includes, or essentially comprises, a tubular body; a targeting system coupled to the tubular body; an expandable member configured to occlude a dilated blood vessel by juxtaposing the side walls of the blood vessel; and a fluid injection port configured to inject radiopaque fluid into a blood vessel proximal to the expandable member in a dilated state, such that radiopaque fluid pools in close proximity to the expandable member and provides visualization of the blood vessel and its branches.

[0023] The expandable member can be coupled to a tubular body. The tubular body may include a fluid injection port. The catheter 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.

[0024] In some embodiments, the catheter system includes, or is essentially composed of, a tubular body, a targeting system coupled to the tubular body, and an expandable member.

[0025] The expandable member can be coupled to a tubular body. The catheter system can further include a second tubular body. The expandable member can be coupled to the second tubular body. The expandable member may be configured to appose side walls of a blood vessel to occlude the blood vessel. The catheter system can further include a fluid injection port. The tubular body can include a fluid injection port. The catheter system can further include a second tubular body that includes a fluid injection port. The targeting system can include an ultrasound transducer. The targeting system can include an omnidirectional ultrasound transducer.

[0026] In some embodiments, the catheter system comprises, or consists essentially of, a tubular body, a targeting system coupled to the tubular body, and a fluid injection port.

[0027] The tubular body can include a fluid injection port. The catheter system can further include a second tubular body that includes a fluid injection port. The catheter system can further include an expandable member. The expandable member can be coupled to the tubular body. The catheter system can further include a second tubular body. The expandable member can be coupled to the second tubular body. The expandable member may be configured to appose side walls of a blood vessel to occlude the blood vessel. The targeting system can include an ultrasound transducer. The targeting system can include an omnidirectional ultrasound transducer.

[0028] In some embodiments, the catheter system comprises, or consists essentially of, a tubular body, a fluid injection port, and an expandable member.

[0029] The tubular body may comprise a fluid injection port. The catheter system may further comprise a second tubular body including a fluid injection port. The expandable member may be coupled to the tubular body. The catheter system may further comprise the second tubular body. The expandable member may be coupled to the second tubular body. The expandable member may be configured to appose sidewalls of a blood vessel to occlude the blood vessel. The catheter system may further comprise a targeting system. The targeting system may comprise an ultrasound transducer. The targeting system may comprise an omnidirectional ultrasound transducer. A method of identifying a bifurcation may comprise inserting a catheter system into a first blood vessel, positioning the catheter system at a first location, expanding an expandable member to occlude the first blood vessel, and delivering a contrast agent to the first blood vessel. The contrast agent may pool proximate to the expandable member. The method may further comprise reviewing a shape of the contrast agent in the first blood vessel under fluoroscopy.

[0030] In some embodiments, a method of identifying a bifurcation comprises, or consists essentially of, inserting a catheter system into a first blood vessel and positioning the catheter system at a first location. The catheter system comprises an expandable member and a fluid injection port. The method further comprises expanding the expandable member to occlude the first blood vessel, and delivering a contrast agent through the fluid injection port. The contrast agent pools proximate to the expandable member. The method further comprises reviewing the shape of the contrast agent in the first blood vessel under fluoroscopy.

[0031] 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 the expansion lumen when fluid is in communication with the expandable member. Expanding the expandable member may include dilating the first blood vessel. The contrast agent may include at least one of an iodine-based contrast agent and a barium sulfate-based contrast agent. Delivering the contrast agent may include dilating the first blood vessel. Reviewing the shape of the contrast agent may include identifying the presence of at least one of a bifurcation and a branching vessel. If at least one of a bifurcation and a branching vessel is present, the method may further include repositioning the catheter system. If at least one of a bifurcation and a branching vessel is not present, the method may further include extending a needle from another catheter in the second blood vessel. Extending the needle may include exiting the second vessel, traversing the interstitial tissue between the second and first vessels, and entering the first vessel. This method may further include advancing a guidewire through the needle. The catheter system may include a capture element configured to guide the guidewire into the guidewire lumen.

[0032] The catheter system may include a targeting system. Positioning the catheter system in a first location may include targeting the targeting system from a complementary targeting system on another catheter in a second blood vessel. The targeting system may include an ultrasound receiver. The complementary targeting system may include an ultrasound emitter. The ultrasound receiver may include an omnidirectional ultrasound transducer. The ultrasound emitter may include a directional ultrasound transducer. This method may further include dilating the fistula.

[0033] This method may further include deploying the prosthesis at least partially in the fistula between the second vessel and the first vessel. After the prosthesis is deployed, blood may be diverted from the first vessel to the second vessel through the prosthesis. After the prosthesis is deployed, this method may further include lining the first vessel with a stent graft, which includes covering the collateral vessels of 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 deploying the most distal stent graft of the multiple stent grafts first and deploying the most proximal stent graft of the multiple stent grafts last. After lining the first vessel with multiple stent grafts, the proximal edge of the most distal stent graft of the multiple stent grafts may overlap with the distal edge of the next most distal stent graft of the multiple stent grafts. After lining the primary vessel with multiple stent grafts, the proximal edge of the most proximal stent graft can overlap with the distal edge of the prosthesis.

[0034] This method may further include deactivating a valve in a first vessel. Deactivating a valve in a first vessel may be done after the vessel has been lined with a stent graft. Deactivating a valve in a first vessel may include advancing a retrograde valve incisor through a prosthesis and advancing the retrograde valve incisor distally in the first vessel to disable the valve. Deactivating a valve in a first vessel may include advancing a bidirectional valve incisor close to the valve in a radially compressed state, radially expanding the bidirectional valve incisor in a radially expanded state, advancing the bidirectional valve incisor distally in the radially expanded state to disable the valve, and retracting the bidirectional valve incisor proximal to the first vessel. Radially expanding the bidirectional valve incisor may include retracting the sheath proximal to the end of the process and advancing the bidirectional valve incisor distally. A method for disabling an intravascular valve may include advancing a bidirectional valve incisor that is close to the valve in a radially compressed state; radially expanding the bidirectional valve incisor in a radially expanded state; distally advancing the bidirectional valve incisor in the radially expanded state to disable the valve; and retracting the bidirectional valve incisor proximal to the valve.

[0035] In some embodiments, a method of modifying a blood vessel, which includes deactivating intravascular valves and covering collateral vessels of the vessel, includes, or essentially consists of, lining the vessel with a stent graft that covers collateral vessels of the vessel, and deactivating intravascular valves after lining the vessel with a stent graft.

[0036] This method may further include deploying a prosthesis at least partially in a fistula between two blood vessels. After the prosthesis is deployed, blood may be diverted from the second blood vessel to the second blood vessel through the prosthesis. Lining the blood vessel with a stent graft may be done after the prosthesis is deployed. This method may further include enlarging the fistula. This method may further include advancing a needle from the second blood vessel to the second blood vessel to form a fistula. Advancing the needle may include targeting the first intravascular catheter with the second catheter in the second blood vessel. The second catheter may include an ultrasound emitter. The first catheter may include an ultrasound receiver. Targeting the intravascular catheter with the second intravascular catheter may include targeting the ultrasound receiver with the ultrasound emitter. This method may further include advancing a guidewire through the needle. The intravascular catheter system may include a capture element configured to guide the guidewire into the guidewire lumen. Lining a vessel with a stent graft may include lining the vessel with multiple stent grafts. Lining a vessel with multiple stent grafts may include deploying the most distal stent graft of the multiple stent grafts first and deploying the most proximal stent graft of the multiple stent grafts last. After lining a vessel with multiple stent grafts, the proximal edge of the most distal stent graft of the multiple stent grafts may overlap with the distal edge of the next most distal stent graft of the multiple stent grafts. After lining a vessel with multiple stent grafts, the proximal edge of the most proximal stent graft of the multiple stent grafts may overlap with the distal edge of a prosthesis within the fistula. Disabling an intravascular valve may include advancing a retrograde valve incision distally within the vessel to disable the valve.Deactivating a vascular valve can include advancing a bidirectional valve incisor adjacent to the valve in a radially compressed state; radially expanding the bidirectional valve incisor in a radially expanded state; distally advancing the bidirectional valve incisor in a radially expanded state to disable the valve; and retracting the bidirectional valve incisor proximal to the vessel. Radially expanding the bidirectional valve incisor can include retracting the sheath proximal to the vessel; and advancing the bidirectional valve incisor distally. This method can further include promoting retrograde perfusion of blood to the toes. Promoting retrograde perfusion of blood to the toes can include inflating a first dilatable member of the medial plantar vein to occlude the medial plantar vein. Promoting retrograde perfusion of blood to the toes can include inflating a second dilatable member of the lateral plantar vein to occlude the lateral plantar vein. Promoting retrograde blood flow to the toes may include increasing hydrostatic pressure in the deep plantar venous arch. Increasing hydrostatic pressure in the deep plantar venous arch may include disabling venous valves and allowing retrograde blood flow to the metatarsal veins.

[0037] In some embodiments, a method for promoting retrograde blood perfusion to the toes includes, or essentially consists of, inflating a first expandable member of the medial plantar vein to occlude the medial plantar vein and increasing the hydrostatic pressure of the deep plantar venous arch. Increasing the hydrostatic pressure of the deep plantar venous arch may include disabling the venous valves and allowing the retrograde flow of blood into the metatarsal veins. This method may further include inflating a second expandable member within the lateral plantar vein to occlude the lateral plantar vein.

[0038] In some embodiments, a catheter system for promoting retrograde blood perfusion to the toes includes, or essentially consists of, a first catheter including a first expandable member configured to expand in the medial plantar vein to occlude the medial plantar vein, and a second catheter including a second expandable member configured to expand in the lateral plantar vein to occlude the lateral plantar vein.

[0039] The first catheter can be made longitudinally movable through the second catheter and the second expandable member. The first catheter may include an expansion lumen that is in fluid communication with the first expandable member. The second catheter may include an expansion lumen that is in fluid communication with the second expandable member. The first catheter may be configured to curve around the lateral plantar vein towards the medial plantar vein.

[0040] In some embodiments, the bidirectional valve incision knife includes, or is essentially composed of, a proximal portion, a distal portion, and a longitudinal intermediate portion between the proximal and distal portions. The intermediate portion includes a blade facing distal and a blade facing proximal.

[0041] The intermediate section may include a strut containing a distally facing blade and a proximal facing blade. The intermediate section may include multiple struts. One of the multiple struts may include a distally facing blade and a proximal facing blade. Each of the multiple struts may include a distally facing blade and a proximal facing blade. At least one of the multiple struts may include a distally facing blade. At least one of the multiple struts may include a proximal facing blade. The intermediate section may include three struts. The three struts may be spaced equally apart in the circumferential direction. The intermediate section may be radially expandable. The intermediate section may self-expand when released from the sheath. The proximal section may be coupled to a pusher element. The intermediate section may be laser-cut (e.g., from a hypo tube or sheet). At least one of the distally facing blade and the proximal facing blade may be rotatable relative to the circumference of the intermediate section.

[0042] In some embodiments, a method for disabling an intravascular valve includes, or essentially consists of, advancing a bidirectional valve incisor adjacent to the valve in a radially compressed state; radially expanding the bidirectional valve incisor in a radially expanded state; advancing the bidirectional valve incisor distally in the radially expanded state to disable the valve; and retracting the bidirectional valve incisor proximal to the valve.

[0043] Advancing a bidirectional valve dissection knife close to the valve may include advancing the bidirectional valve dissection knife in the direction opposite to the original fluid flow. Advancing a bidirectional valve dissection knife close to the valve may include advancing the bidirectional valve dissection knife in the direction of the original fluid flow. Advancing a bidirectional valve dissection knife close to the valve may include advancing a bidirectional valve dissection knife proximal to the valve. Advancing a bidirectional valve dissection knife close to the valve may include advancing a bidirectional valve dissection knife distal to the valve.

[0044] In some embodiments, a catheter for capturing a guidewire includes, or essentially consists of, a catheter body, a capture element, and a guidewire lumen communicating with the capture element.

[0045] The capture element may be configured to deploy from the distal end of the catheter body. The capture element may be configured to deploy from the side of the catheter body. The capture element may have a compressed state and an expanded state. The capture element may include a shape memory material configured to change to an expanded state at body temperature. The capture element may have an angle of 110° to 150° in the expanded state. The guidewire lumen may include an expanded portion adjacent to the capture element. The catheter may further include an expandable element configured to expand the capture element. The expandable element may include an inflatable member. The catheter body may include an expansion lumen that is in fluid communication with the inflatable member. The expandable element may be movable relative to the catheter body.

[0046] In some embodiments, a method for disabling a valve includes, or alternatively, essentially 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 comprises an ultrasonic sound emitting 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 comprises an ultrasonic receiving transducer. Forming the fistula further includes transmitting an ultrasonic signal from the ultrasonic sound emitting transducer and, after the ultrasonic signal is received by the ultrasonic receiving transducer, extending the needle from the first catheter. Extending the 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 the prosthesis at least partially in the fistula. After deploying the implantable prosthesis, blood is diverted through the prosthesis from the first blood vessel to the second blood vessel. The method further includes deactivating the valve in the second blood vessel. Deactivating the valve in the second blood vessel includes excising the valve using a retrograde valve incision knife and lining the second blood vessel with a stent.

[0047] The stent may be equipped with a covering or graft. Lining the second vessel may include covering collateral vessels of the second vessel. The stent may be separate from the prosthesis. The stent may be spaced apart from the prosthesis along the length of the second vessel. The stent may be integrated with the prosthesis.

[0048] In some embodiments, a method for deactivating a valve includes, or alternatively, essentially forming a fistula between a first blood vessel and a second blood vessel. Forming a fistula includes inserting a catheter into the first blood vessel. The catheter comprises a needle configured to extend radially from the first catheter. Forming a fistula further includes extending the needle from the first catheter. Extending the 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 the implanted prosthesis is deployed, blood is diverted through the prosthesis from the first blood vessel to the second blood vessel. The method further includes deactivating a valve in the second blood vessel. Deactivating the valve in the second vessel includes at least one of the following: excising the valve using a retrograde valve incision knife, inflating a balloon, expanding a temporary stent, and lining the second vessel with an implantable stent.

[0049] An implantable stent may be equipped with a covering material or graft. Lining a second vessel may include covering collateral vessels of the second vessel. An implantable stent may be separate from a prosthesis. An implantable stent may be integrated with a prosthesis. The first catheter may be equipped with an ultrasonic transmitting transducer. Forming a fistula may include inserting a second catheter equipped with an ultrasonic receiving transducer into the second vessel, transmitting an ultrasonic signal from the ultrasonic transmitting transducer, and extending a needle from the first catheter after the ultrasonic receiving transducer has received the ultrasonic signal.

[0050] In some embodiments, a method for deactivating a valve includes, or alternatively, essentially deploying a prosthesis in such a manner, at least partially in a fistula between a first blood vessel and a second blood vessel. After the implanted prosthesis is deployed, blood is diverted through the prosthesis from the first blood vessel to the second blood vessel. The method further includes deactivating a valve in the second blood vessel.

[0051] Deactivating the valve in the second vessel may include resecting the valve using a retrograde valve incisor. Deactivating the valve in the second vessel may include lining the second vessel with a stent. The stent may comprise a covering or graft. Lining the second vessel may include covering collateral vessels of the second vessel. The stent may be separate from the prosthesis. The stent may be spaced apart from the prosthesis along the length of the second vessel. The proximal segment of the stent may overlap the distal segment of the prosthesis in the longitudinal direction. The stent may be integral with the prosthesis. Deactivating the valve in the second vessel may include resecting the valve using a retrograde valve incisor and lining the second vessel with a stent. Deactivating the valve in the second vessel may include inflating a balloon and expanding a temporary stent. Deactivating the valve in the second vessel may include inflating a balloon. Deactivating the valve in the second blood vessel may involve expanding a temporary stent.

[0052] In some embodiments, an implantable prosthesis for treating an occlusion in a first blood vessel comprises a plurality of filaments woven together in a woven structure, a proximal end, a distal end, a side wall between the proximal and distal ends, a lumen defined by the side wall, and a porosity sufficient to direct fluid flow through the lumen without substantially passing through the side wall and perfusing, or alternatively, essentially comprises a plurality of filaments woven together in such a woven structure, a proximal end, a distal end, a side wall between the proximal and distal ends, a lumen defined by the side wall, and a porosity sufficient to direct fluid flow through the lumen without substantially passing through the side wall and perfusing.

[0053] The porosity can be approximately 0% to approximately 50%. The porosity can be approximately 5% to approximately 50%. The prosthesis may substantially not have graft material. The prosthesis may have a first longitudinal segment having the above porosity and a second longitudinal segment having a second porosity different from the above porosity. The second longitudinal segment may have different parameters from the first longitudinal segment. The parameters may include at least one of the braiding angle, filament diameter, filament material, woven structure diameter, woven structure shape and auxiliary support structure. The prosthesis may further have a third longitudinal segment between the first longitudinal segment and the second longitudinal segment. The third longitudinal segment may have different parameters from at least one of the first longitudinal segment and the second longitudinal segment. The parameters may include at least one of the braiding angle, filament diameter, filament material, woven structure diameter, woven structure shape and auxiliary support structure. The prosthesis may further comprise an auxiliary support structure. The auxiliary support structure may include a second plurality of filaments woven together in a second woven structure, the second plurality of filaments having different parameters from the above plurality of filaments. The parameters may include at least one of the braiding angle, filament diameter, woven structure diameter, and filament material. The auxiliary support structure may include a cut hypotube. The plurality of filaments may include filaments containing a shape memory material (e.g., nitinol) and a prosthesis containing a biocompatible polymer (e.g., Dacron®, Kevlar®).

[0054] In some embodiments, an implantable prosthesis for treating an occlusion in a first blood vessel comprises a proximal end, a distal end, a lateral wall between the proximal and distal ends, a lumen defined by the lateral wall, a first longitudinal section configured to be placed in the first lumen, a second longitudinal section configured to be placed in the second lumen, and a third longitudinal section between the first and second longitudinal sections; or alternatively, essentially comprising a proximal end, a distal end, a lateral wall between the proximal and distal ends, a lumen defined by the lateral wall, a first longitudinal section configured to be placed in the first lumen, a second longitudinal section configured to be placed in the second lumen, and a third longitudinal section between the first and second longitudinal sections. At least one of the first longitudinal section and the third longitudinal section has a porosity sufficient to direct the fluid flow through the lumen without substantially perfusing through the side walls.

[0055] The porosity can be approximately 0% to approximately 50%. The porosity can be approximately 5% to approximately 50%. The prosthesis may substantially not require graft material. The second longitudinal segment may have different parameters from the first longitudinal segment. The parameters may include at least one of the braiding angle, filament diameter, filament material, diameter, shape, and auxiliary support structure. The third longitudinal segment may have a second porosity different from the above porosity. The first longitudinal segment may be balloon expandable. The second longitudinal segment may be self-expanding. The prosthesis may include a plurality of filaments woven together in a woven structure. The plurality of filaments may include filaments containing a shape memory material (e.g., nitinol) and a prosthesis containing a biocompatible polymer (e.g., Dacron®, Kevlar®). The third longitudinal section may have different parameters from at least one of the first longitudinal section and the second longitudinal section. The parameters may include at least one of the braiding angle, filament diameter, filament material, diameter, shape, and auxiliary support structure. The prosthesis may further comprise an auxiliary support structure. The first longitudinal section may be substantially cylindrical and have a first diameter, the second longitudinal section may be substantially cylindrical and have a second diameter greater than the first diameter, and the third longitudinal section may be frustoconical and tapered from the first diameter to the second diameter. The first longitudinal section may be substantially cylindrical and have a first diameter, and the second and third longitudinal sections may be frustoconical and tapered from the first diameter to a second diameter greater than the first diameter.

[0056] In some embodiments, an implantable prosthesis for treating an occlusion in a first blood vessel comprises a plurality of filaments woven together in a woven structure, a proximal end, a distal end, a side wall between the proximal and distal ends, a lumen defined by the side wall, and a porosity of about 5% to about 50%.

[0057] The porosity can be configured to direct the fluid flow substantially through the lumen. The prosthesis may have a first longitudinal segment having the above porosity and a second longitudinal segment having a second porosity different from the above porosity.

[0058] In some embodiments, the kit comprises a prosthesis and a fistula formation system. The kit may further comprise a valve deactivation device. In some embodiments, the kit comprises a prosthesis and a valve deactivation device. The kit may comprise a prosthesis delivery system including the prosthesis. In some embodiments, the method comprises deploying the prosthesis in a fistula between a first vessel and a second vessel. The valve deactivation device may include a retrograde valve incision knife. The valve deactivation device may include a balloon. The valve deactivation device may include a venous stent. The venous stent may comprise a covering or a graft. The venous stent may be integrated with the prosthesis.

[0059] In some embodiments, a method for diverting fluid flow from a first vessel to a second vessel, including occlusion, involves deploying a prosthesis at least partially in a fistula between the first and second vessels. The prosthesis comprises multiple filaments woven together into a woven structure having a porosity of less than approximately 50%. After the implantable prosthesis is deployed, blood can be diverted through the prosthesis from the first vessel to the second vessel.

[0060] The first vessel may be an artery. The conduit may be a vein. The method may include dilating the fistula. The first vessel may be substantially parallel to the second vessel. Deploying the prosthesis may include self-expanding the prosthesis. Deploying the prosthesis may include a balloon expanding the prosthesis. Deploying the prosthesis may include deploying a woven structure and deploying an auxiliary support structure. Deploying the auxiliary support structure may be done before deploying the woven structure. Deploying the auxiliary support structure may be done after deploying the woven structure. The auxiliary support structure may include a second set of filaments woven into the second woven structure. The auxiliary support structure may include a cut hypotube. The method may further include forming a fistula. Forming a fistula may include inserting a firing catheter into the first vessel and inserting a target catheter into the second vessel. The firing catheter may comprise an ultrasonic transmitting transducer and a needle configured to extend radially from the firing catheter. The target catheter may be equipped with an ultrasonic receiving transducer. Forming a fistula involves transmitting an ultrasonic signal from an ultrasonic transmitting transducer, rotating the firing catheter and moving the firing catheter longitudinally while transmitting the ultrasonic signal until the ultrasonic signal can be received by the ultrasonic receiving transducer, and extending a needle from the firing catheter after the ultrasonic receiving transducer has received the ultrasonic signal, the extension of which needle may include exiting a first blood vessel, crossing the interstitial tissue between the first and second blood vessels, and entering the second blood vessel. The method may further include disabling a valve in the second blood vessel. Disabling a valve in the second blood vessel may include resecting the valve using a retrograde valve incisor. Disabling a valve in the second blood vessel may include inflating a balloon.Deactivating the valve in the second vessel may include expanding the stent. Deactivating the valve in the second vessel may include lining the second vessel with a stent. The stent may comprise a covering or graft. Lining the second vessel may include covering collateral vessels of the second vessel. The stent may be separate from the prosthesis. The stent may be spaced apart from the prosthesis along the length of the second vessel. The ends of the stent may abut against the ends of the prosthesis. Part of the stent may overlap part of the prosthesis in the longitudinal direction. The above-mentioned portion of the stent may be radially medial to the above-mentioned portion of the prosthesis. This method may include expanding the stent after deploying the prosthesis. The above-mentioned portion of the prosthesis may be radially medial to the above-mentioned portion of the stent. This method may include expanding the stent before deploying the prosthesis. The stent may be integrated with the prosthesis.

[0061] In some embodiments, an implantable prosthesis for maintaining the patency of an anastomosis between an artery and a vein in a lower limb comprises a first section configured to remain in a lower limb artery, a second section configured to remain in a lower limb vein, and a third section located longitudinally between the first and second sections. The third section is configured to maintain the patency of the anastomosis between the artery and the vein.

[0062] The first section may be configured to juxtapose the walls of the lower extremity arteries. The first section may have a return. The second section may be configured to juxtapose the walls of the lower extremity veins. The second section may have a return. At least one of the first, second, and third sections may be self-expanding. At least one of the first, second, and third sections may be balloon-inflatable. The length of the second section may be greater than the length of the first section. The second section may be configured to neutralize valves in the lower extremity veins. The second section may be configured to cover collateral vessels of the lower extremity veins.

[0063] In some embodiments, a method for diverting fluid flow from a first blood vessel to a second blood vessel in a lower limb includes forming a hole between the first blood vessel and the second blood vessel, and expanding the hole to form an anastomosis.

[0064] Creating a hole may include advancing a wire from a first blood vessel into a second blood vessel. Creating a hole may also include traversing a needle from a first blood vessel into a second blood vessel. Expanding a hole may include enlarging the hole using at least one balloon. Enlarging a hole may include using multiple balloons having progressively larger diameters. The first balloon of the multiple balloons may have a diameter of approximately 1.5 mm, and the last balloon of the multiple balloons may have a diameter of approximately 3 mm. The multiple balloons may include a first balloon with a diameter of approximately 1.5 mm, a second balloon with a diameter of approximately 2.0 mm, a third balloon with a diameter of approximately 2.5 mm, and a third balloon with a diameter of approximately 3.0 mm. Enlarging a hole using multiple balloons may include using progressively higher balloon inflation pressures. This method does not necessarily involve placing a prosthesis (e.g., without using a stent, graft, scaffold, or other prosthesis) (e.g., it may be omitted or excluded). The positions of the first and second vessels can be substantially maintained by the anatomical structures surrounding them. The method may further include placing a prosthesis at the anastomosis. Placing a prosthesis at the anastomosis may include placing the prosthesis within at least one of the first and second vessels. The first vessel may include the lateral plantar artery. The second vessel may include the lateral plantar vein.

[0065] In some embodiments, the catheter for capturing the guidewire includes or is essentially composed of a sheath and an expandable element. The expandable element has a compressed state when inside the sheath and an expanded state when outside the sheath. The expandable element includes a plurality of cells configured to snare the guidewire.

[0066] The catheter may further include a sheath and a guidewire sheath extending through an expandable element. The proximal end of the expandable element may be coupled to the guidewire sheath. The expandable element may be configured to expand a vessel upon deployment. The expandable element is visible under fluoroscopy. The expandable element may include struts that define multiple cells. The struts may be deflectable upon contact with 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 located between the proximal and distal ends of the expandable element. The ultrasound-receiving transducer may be proximal to the expandable element. A method for capturing a guidewire may include inserting a catheter into a first blood vessel, expanding an expandable element in the first blood vessel, and extending a needle from a second blood vessel through interstitial tissue into the first blood vessel between the proximal and distal ends of the expandable element. Extending the needle may include extending it through one of several cells. This method may further include extending a guidewire through the needle into the expandable element and collapsing the expandable element toward a collapsed state. Collapsing the expandable element may include snare the guidewire.

[0067] In some embodiments, a method for capturing a guidewire includes, or essentially consists of, expanding an expandable element into an expanded state within a first blood vessel and extending a needle from a second blood vessel through interstitial tissue into the first blood vessel between the proximal and distal ends of the expandable element. The expandable element comprises a plurality of cells. Extending the needle includes extending it through one of the plurality of cells. The method further includes extending a guidewire through the needle into the expandable element and collapsing the expandable element toward a collapsed state. Collapsing the expandable element includes snare the guidewire.

[0068] Crushing the expandable element may include twisting the expandable element. Expanding the expandable element may include expanding the first vessel. Extending the needle may include targeting the expandable element under fluoroscopy. This method may further include retracting the expandable element proximal to the first vessel. Retracting the expandable element proximal to the first vessel may include routing a guidewire through the first vessel.

[0069] In some embodiments, the apparatus for deploying a tubular structure includes, or essentially consists of, a handle body, a knob, and a slider. The handle body includes a first segment having threads, a second segment longitudinally adjacent and proximal to the first segment, and a longitudinal slot. The second segment does not have threads. The knob has threads. The knob is located at the distal end of the first segment in the starting 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 of the first segment and to slide proximal to the handle body of the second segment. The slider is configured to retract the sheath proximal by a first amount while the knob is being rotated and to retract the sheath proximal by a second amount while the knob is being slid. The apparatus is configured to fully deploy the tubular structure after the sheath has retracted by the second amount.

[0070] The first quantity can be less than the second quantity. The first quantity can be 10% to 50% of the second quantity. The tubular structure can contain a stent. The tubular structure can contain a stent graft.

[0071] In some embodiments, the method for deploying the tubular structure includes, or essentially consists of, rotating a knob around a handle body. Rotating the knob around the handle body includes retracting the sheath proximally and deploying a first amount of the tubular structure. This method further includes, after rotating the knob around the handle body, sliding the knob proximally along the handle body. Sliding the knob proximally along the handle body includes retracting the sheath proximally to deploy a second amount of the tubular structure. The first and second amounts are the total amounts of the tubular structure.

[0072] The first quantity can be less than the second quantity. The first quantity can be 10% to 50% of the second quantity. The tubular structure can contain a stent. The tubular structure can contain a stent graft.

[0073] In some embodiments, a device for deploying a tubular structure includes, or essentially consists of, a sheath, a handle body, a knob including a worm gear including 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 screw including teeth configured to interact with the teeth of the worm gear. The slider is configured to retract the sheath proximal by a first amount while the knob is rotated, and to retract the sheath proximal by a second amount while the slider is slid. The device is configured to fully deploy the tubular structure after the sheath has been retracted by the second amount.

[0074] The first amount can be less than the second amount. The first amount can be 10% to 50% of the second amount. The tubular structure can include a stent. The tubular structure can include a stent graft. The handle body can include a longitudinal slot. The slider can include a third portion extending through the longitudinal slot. The handle body can include a second longitudinal slot. The slider can include a fourth portion on the outside of the handle body and a fifth portion extending through the second longitudinal slot. The fourth portion can be on the opposite side of the handle body from the second portion. The handle body can include a shell that at least partially covers the second portion of the slider until the sheath can be retracted proximal by the first amount.

[0075] In some embodiments, the method for deploying the tubular structure includes, or essentially consists of, rotating a knob. Rotating the knob includes retracting the sheath proximally and deploying a first amount of the tubular structure. After rotating the knob, the method further includes 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 a second amount of the tubular structure. The first and second amounts are the total amount of the tubular structure.

[0076] The first amount can be less than the second amount. The first amount can be 10% to 50% of the second amount. The tubular structure can include a stent. The tubular structure can include a stent graft. The knob can include a worm gear containing teeth. The slider can include a worm screw containing teeth configured to interact with the teeth of the worm gear. The handle body can include a longitudinal slot. The slider can include a first part inside the handle body, a second part outside the handle body, and a third part extending through the longitudinal slot. The handle body can include a second longitudinal slot. The slider can include a fourth part outside the handle body and a fifth part extending through the second longitudinal slot. The fourth part can be on the opposite side of the handle body from the second part. Retracting the slider proximal can include gripping the second and fourth parts. The handle body may include a shell that at least partially covers a second portion of the slider until the sheath can be retracted proximally by a first amount. The axis of rotation of the knob may traverse the longitudinal axis of the handle body.

[0077] In some embodiments, a method for accessing the tibial vein of interest includes, or essentially consists of, placing a first tourniquet above the knee of the leg, placing a second tourniquet above the ankle of the leg, injecting a certain amount of contrast agent into the metatarsal vein, and creating a venogram to image the veins of the leg and foot using fluoroscopy.

[0078] The first tourniquet may be of a different type than the second tourniquet. The first tourniquet may be of the same type as the second tourniquet. The first tourniquet may be of the same size as the second tourniquet. The first tourniquet may be of a different size than the second tourniquet. This method may further include positioning the subject in the reverse Trendelenburg position. This method may further include injecting a certain amount of contrast agent through the metatarsal vein and then flattening the subject. The contrast agent may include a non-ionic contrast agent. The contrast agent may include a mixture of the contrast agent and saline. The contrast agent may include a 50 / 50 dilution of the contrast agent and saline. The amount of contrast agent may be between 5 mL and 50 mL. The metatarsal vein may be the dorsal metatarsal vein. The metatarsal vein may be the plantar metatarsal vein. This method may further include palpating the metatarsal vein. This method may further include selecting the tibial vein using venography. This method may further include advancing a guidewire into the target tibial vein. This method may further include removing a second tourniquet. This method may further include tracking a functional catheter along the guidewire. The functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a discharge catheter). The functional catheter may include a snare.

[0079] In some embodiments, a method for accessing the target lateral plantar vein includes, or essentially consists of, placing a first tourniquet above the ankle of the leg, positioning a needle in the dorsomedial marginal vein toward the toes of the foot of the leg, advancing a first guidewire into the first metatarsal vein of the foot, injecting a certain amount of contrast agent, and creating a venogram to image the veins of the foot of the leg using fluoroscopy.

[0080] The contrast agent may include a non-ionic contrast agent. The contrast agent may include a mixture of the contrast agent and saline. The contrast agent may include a 50 / 50 dilution of the contrast agent and saline. The amount of contrast agent may be between 5 mL and 50 mL. This method may further include selecting the two larger lateral plantar veins using venography. This method may further include advancing the first guidewire to at least one intersection or above the ankle and observing the position of the first guidewire by examining the veins in the plantar foot using ultrasound. This method may further include advancing the first guidewire to at least one intersection or above the ankle, observing the position of the first guidewire by examining the veins in the plantar foot using ultrasound and accessing the lateral plantar vein containing the first guidewire as distal as possible in the plantar arch of the foot at a second access site. This method may further include advancing the second guidewire into the lateral plantar vein. This method may further include advancing a second guidewire into the posterior tibial vein and to the intersection. This method may further include removing the first guidewire. This method may further include removing the tourniquet. This method may further include tracking a functional catheter along the guidewire. The functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a launching catheter). The functional catheter may include a snare.

[0081] In some embodiments, a method for performing ascending venography involves, or essentially consists of, injecting a certain amount of contrast agent into the venous vascular system from a first metatarsal vein.

[0082] In some embodiments, a method for performing descending venography involves, or essentially consists of, injecting a certain amount of contrast agent into the venous vascular system from the great saphenous vein toward the leg.

[0083] In some embodiments, a method for aligning a catheter for venous arterialization procedures includes inserting a first catheter into a first blood vessel. The first catheter includes a needle opening on a first side of a needle, a radiopaque marker distal to the needle opening and on a second side of the first catheter opposite to the first side, and a needle configured to extend through the needle opening. The radiopaque marker is visible under fluoroscopy. 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. Inflating the balloon includes inflating the balloon with a radiopaque material visible under fluoroscopy. The method further includes advancing the first catheter longitudinally until the radiopaque marker is close to the second catheter in the second blood vessel, and aligning the needle opening of the first catheter with the second catheter. Aligning the needle opening involves rotating the first catheter within the first blood vessel so that a radiopaque marker transitions between a first and a second position. This method further includes monitoring the rotation of the radiopaque marker to the second position to confirm rotational alignment of the needle opening and the second catheter, and, after confirming rotational alignment, extending the needle from the needle opening of the first catheter. Extending the needle involves exiting the first blood vessel, traversing the interstitial tissue between the first and second blood vessels, and entering the second blood vessel.

[0084] This method may further include extending a guidewire through a needle into a second blood vessel and entangling the guidewire with a second catheter within the second blood vessel. Entangling the guidewire may include occluding an expandable portion of the second catheter. After extending the guidewire, this method may further include moving the second catheter to detect the corresponding movement of the guidewire and confirming the entanglement of the guidewire in the second catheter. This 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 certain position in the leg.

[0085] In some embodiments, a method for aligning a catheter for venous arterialization procedures 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 includes a radiopaque material visible under fluoroscopy. The method further includes expanding the expandable member and aligning the needle of the first catheter with the second catheter. Needle alignment includes rotating the first catheter within the first blood vessel so that the radiopaque marker transitions between a first and a second position. The method further includes monitoring the rotation of the radiopaque marker to 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 along the extension path. Extending the needle involves exiting the first blood vessel, traversing the interstitial tissue between the first and second blood vessels, and entering the second blood vessel.

[0086] This method may further include extending a guidewire through a needle into a second blood vessel. Extending the guidewire may include entangling the guidewire with the expandable member of the second catheter. This method may further include retracting the expandable member through the second blood vessel. Retracting the expandable member may include advancing the guidewire through the second blood vessel. Entangling the guidewire may include occluding the expandable member of the second catheter. A radiopaque marker may be located on the side of the first catheter opposite the needle extension path. A radiopaque marker may be located distal to the needle exit opening. The second catheter may include a balloon. The balloon may be inflated with a radiopaque material.

[0087] In some embodiments, a method for aligning a catheter for venous arterialization procedures 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 into the second blood vessel.

[0088] This method may further include extending a guidewire through a needle into a second blood vessel and entangling the guidewire with a second catheter. Entangling the guidewire may include occluding an expandable member. This method may further include moving the second catheter to move the guidewire through the second blood vessel. Aligning the needle extension path with the second blood vessel may include rotating the first catheter within the first blood vessel so that the radiopaque marker transitions between a first and a second position. The first position may include a first thickness visible under fluoroscopy. The second position may include a second thickness visible under fluoroscopy. The first thickness may be different from the second thickness. The first catheter may include a needle opening on the first side. The radiopaque marker may be on the 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 an expandable member may include inflating a balloon with a radiopaque material.

[0089] In some embodiments, a method for accessing the tibial vein of a subject includes positioning the subject in the reverse Trendelenburg position, placing a first tourniquet above the knee of the leg, placing 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 a certain amount of contrast agent through the metatarsal vein, creating a venogram to image the veins of the leg and foot using fluoroscopy, selecting the tibial vein using the venogram, advancing a guidewire into the selected tibial vein, removing the second tourniquet, tracking a functional catheter on the guidewire, snare the second guidewire extending from the artery using the functional catheter, retracting the second guidewire from the foot, and tracking the second functional catheter on the second guidewire. The metatarsal vein may be the dorsal metatarsal vein. The metatarsal vein may be the plantar metatarsal vein. A functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a launch catheter). A second functional catheter may include a valve deactivation device. The valve deactivation device may include a valve incision knife. The valve deactivation device may include a cutting balloon. The valve deactivation device may include an atherectomy device.

[0090] In some embodiments, a method for accessing a target tibial vein includes injecting a certain amount of contrast agent through the metatarsal vein; creating a venogram to image the veins of the leg and foot using fluoroscopy; selecting the tibial vein using the venogram; advancing a guidewire into the selected tibial vein; tracking a functional catheter on the guidewire; extending a second guidewire from the artery into the tibial vein; snare the second guidewire using the functional catheter; retracting the second guidewire from the foot; and tracking a second functional catheter on the second guidewire.

[0091] The metatarsal vein may be the dorsal metatarsal vein. The metatarsal vein may be the plantar metatarsal vein. The functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a discharge catheter). The second functional catheter may include a valve deactivation device. The valve deactivation device may include a valve incision knife. The valve deactivation device may include a cutting balloon. The valve deactivation device may include an atherectomy device.

[0092] In some embodiments, a method for accessing a target tibial vein includes injecting a certain amount of contrast agent through the metatarsal vein, creating a venogram to image the veins of the leg and foot using fluoroscopy, selecting the tibial vein using the venogram, advancing a guidewire into the selected tibial vein, and tracking a functional catheter along the guidewire.

[0093] The metatarsal vein may be the dorsal metatarsal vein. The metatarsal vein may be the plantar metatarsal vein. The functional catheter may include an element configured to snare a guidewire. This method may further include snare a second guidewire extending from the artery using the functional catheter and retracting the second guidewire. This method may further include tracking a second functional catheter on 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 valve deactivator. The valve deactivator may include a valve cutting knife. The valve deactivator may include a cutting balloon. The valve deactivator may include an atherectomy device.

[0094] In some embodiments, the cutting snare system includes, or is essentially composed of, a snare structure and a valve cutting knife structure.

[0095] The system may further include an outer sheath. The snare structure and valve incision blade structure may be interchangeable in the outer sheath. The valve incision blade structure may be proximal to the snare structure. The snare structure may be configured to extend from the distal end of the outer sheath. The valve incision blade structure may be monolithic with the snare structure. The outer sheath may include multiple openings. The valve incision blade structure may be configured to extend laterally from the outer sheath through multiple openings. The snare structure may include multiple cells configured to receive a guidewire. The snare structure may include multiple struts configured to snare the guidewire. The snare structure may include multiple wires configured to snare the guidewire. The valve incision blade structure may be proximal to the snare structure. The valve incision blade structure may be distal to the snare structure. The valve incision blade structure may be monolithic with the snare structure. The snare structure may have a first diameter, and the valve incision knife structure may have a second diameter smaller than the first diameter. The snare structure may be configured to invert into the valve incision knife structure when a longitudinal force is applied to the snare structure. The valve incision knife structure may be separated from the snare structure. The valve incision knife structure may be configured to fit into the snare structure. The snare structure may be configured to fit into the valve incision knife structure. The valve incision knife structure may include an expandable member configured to apply a radially outward force to the snare structure. The valve incision knife structure may include multiple blades. The multiple blades may range from two blades to eight blades. The multiple blades may include three blades. The multiple blades may include four blades. The multiple blades may face proximal. The multiple blades may face distal. The multiple blades may face proximal and distal.

[0096] In some embodiments, the cutting snare system includes, or essentially consists of, a snare structure comprising a plurality of cells configured to receive a guide wire, a valve cutting blade structure comprising two proximal-facing blades and eight proximal-facing blades, and an outer sheath. The snare structure and the valve cutting blade structure are extendable from the outer sheath. The valve cutting blade structure can be monolithic with the snare structure.

[0097] In some embodiments, a method for accessing the plantar veins of a subject includes positioning the subject in the reverse Trendelenburg position, placing a first tourniquet above the knee of the leg, placing a second tourniquet above the ankle of the leg, injecting a certain amount of contrast agent through the metatarsal veins, flattening the subject after injecting a certain amount of contrast agent through the metatarsal veins, creating a venogram to image the veins of the leg and foot using fluoroscopy, selecting the plantar veins using the venogram, advancing a guidewire into the selected plantar veins, removing the second tourniquet, tracking a functional catheter on the guidewire, snare the second guidewire extending from the artery using the functional catheter, retracting the second guidewire from the foot, and tracking the second functional catheter on the second guidewire.

[0098] The metatarsal vein may be the dorsal metatarsal vein. The metatarsal vein may be the plantar metatarsal vein. The functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a discharge catheter). The second functional catheter may include a valve deactivation device. The valve deactivation device may include a valve incision knife. The valve deactivation device may include a cutting balloon. The valve deactivation device may include an atherectomy device.

[0099] In some embodiments, a method for accessing a target plantar vein includes injecting a certain amount of contrast agent through the metatarsal vein; creating a venogram to image the veins of the leg and foot using fluoroscopy; selecting a plantar vein using the venogram; advancing a guidewire into the selected plantar vein; tracking a functional catheter on the guidewire; extending a second guidewire from the artery into the plantar vein; snare the second guidewire using the functional catheter; withdrawing the second guidewire from the foot; and tracking a second functional catheter on the second guidewire.

[0100] The metatarsal vein may be the dorsal metatarsal vein. The metatarsal vein may be the plantar metatarsal vein. The functional catheter may include a catheter for forming a fistula (e.g., a target catheter, a discharge catheter). The second functional catheter may include a valve deactivation device. The valve deactivation device may include a valve incision knife. The valve deactivation device may include a cutting balloon. The valve deactivation device may include an atherectomy device.

[0101] In some embodiments, a method for accessing a target plantar vein includes injecting a certain amount of contrast agent through the metatarsal vein, creating a venogram to image the veins of the leg and foot using fluoroscopy, selecting a plantar vein using the venogram, advancing a guidewire into the selected plantar vein, and tracking a functional catheter along the guidewire.

[0102] The metatarsal vein may be the dorsal metatarsal vein. The metatarsal vein may be the plantar metatarsal vein. The functional catheter may include an element configured to snare a guidewire. This method may further include snare a second guidewire extending from the artery using the functional catheter and retracting the second guidewire. This method may further include tracking a second functional catheter on 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 valve deactivator. The valve deactivator may include a valve cutting knife. The valve deactivator may include a cutting balloon. The valve deactivator may include an atherectomy device.

[0103] In some embodiments, a method for accessing the plantar veins of a subject includes positioning the subject in the reverse Trendelenburg position, placing a first tourniquet above the knee of the leg, placing a second tourniquet above the ankle of the leg, injecting a certain amount of contrast agent through the metatarsal veins, flattening the subject after injecting a certain amount of contrast agent through the metatarsal veins, creating a venogram to image the veins of the leg and foot using fluoroscopy, selecting the plantar veins using the venogram, advancing a guidewire into the selected plantar veins, removing the second tourniquet, tracking a functional catheter on the guidewire, snare the second guidewire extending from the vein using the functional catheter, retracting the second guidewire from the foot, and tracking the second functional catheter on the second guidewire.

[0104] The metatarsal vein may be the dorsal metatarsal vein. The metatarsal vein may be the plantar metatarsal vein. The functional catheter may include a catheter for forming a fistula. The second functional catheter may include a valve deactivation device. The valve deactivation device may include a valve incision knife.

[0105] In some embodiments, a method for accessing the target tibial vein includes placing a first tourniquet above the knee of the leg, placing a second tourniquet above the ankle of the leg, injecting a certain amount of contrast agent through the metatarsal veins, creating a venogram to image the veins of the leg's foot using fluoroscopy, selecting the tibial vein using the venogram, advancing a guidewire into the selected tibial vein, removing the second tourniquet, and tracking a functional catheter along the guidewire. The first tourniquet may be of a different type than the second tourniquet.

[0106] In some embodiments, a method for aligning a catheter includes positioning a first catheter in a first blood vessel and positioning the 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 the imaging system until the first catheter and the catheter are in the imaging plane. Rotating the imaging system includes drawing a first centerline on the first catheter, drawing a second centerline on the catheter, maximizing the distance between the first and second centerlines, and creating a signal that the first catheter and the catheter are 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 involves drawing a first line along the first long edge of a flat rectangular radiopaque marker, drawing a second line along the second long edge of the flat rectangular radiopaque marker opposite to the first long edge, minimizing the distance between the first and second lines, and creating a signal that the thickness is minimal. The method further includes extending a needle in the imaging plane from the catheter in the second vessel out of the second vessel and into the first vessel.

[0107] In some embodiments, a catheter alignment method includes positioning a first catheter in a first blood vessel and positioning the catheter in a second blood vessel. The first catheter comprises a radiopaque material. The catheter comprises a radiopaque marker. The method further includes rotating the imaging system until the first catheter and the catheter are within the imaging plane and rotating the catheter until the thickness of the radiopaque marker is minimized. Rotating the catheter includes creating a signal that the thickness is minimized.

[0108] In some embodiments, a method for aligning a catheter includes positioning a catheter containing a radiopaque marker into a blood vessel and rotating the catheter until the thickness of the radiopaque marker is minimized. Rotating the catheter may include creating a signal that the thickness is minimized.

[0109] In some embodiments, a method for aligning a first blood vessel and a second blood vessel to an imaging plane includes positioning a first catheter in the first blood vessel and positioning a second catheter in the second blood vessel. The first catheter includes a radiopaque material. The second catheter includes a radiopaque marker. The method further includes rotating the imaging system until the first catheter and the second catheter are in the imaging plane. Rotating the imaging system includes drawing a first centerline on the first catheter and a second centerline on the second catheter, maximizing the distance between the first and second centerlines, and creating a signal that the first catheter and the second catheter are in the imaging plane.

[0110] 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 the imaging system until the first and second blood vessels are in the 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 creating a signal that the first and second blood vessels are 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 the first long edge of a flat rectangular radiopaque marker, drawing a second line along the second long edge of the flat rectangular radiopaque marker opposite to the first long edge, minimizing the distance between the first and second lines, and creating a signal that the thickness is minimal. The method further includes extending a needle in the imaging plane from the catheter in the second vessel out of the second vessel and into the first vessel.

[0111] 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 the imaging system until the first and second blood vessels are in the 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 creating a signal that the first and second blood vessels are in the imaging plane. The method further includes positioning the catheter in the second blood vessel.

[0112] In some embodiments, a method for aligning a first vessel and a second vessel to an imaging plane includes injecting a contrast agent into the first vessel, injecting a contrast agent into the second vessel, and rotating the imaging system until the first vessel and the second vessel are within the imaging plane.

[0113] In some embodiments, a method for aligning a catheter includes positioning a first catheter in a first blood vessel and positioning the 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 minimized and creating a signal that the thickness is minimized.

[0114] In some embodiments, a method for aligning a catheter includes positioning a first catheter in a first blood vessel and positioning the 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 creating a signal that the thickness is less than that value. The value can be less than 3 mm. The value can be less than 1 mm. The value can be less than 10 μm.

[0115] The methods outlined above and described in more detail below describe some measures taken by general practitioners, but it should be understood that they can also include instructions for such measures to be taken by others. Therefore, measures such as "deactivating the valve in the first blood vessel" include "instructing to deactivate the valve in the first blood vessel."

[0116] For the purpose of outlining the present invention and the advantages that can be achieved, several objectives and advantages are described herein. Not all such objectives or advantages are necessarily required to be achieved according to any particular embodiment. In some embodiments, the present invention can be embodied or can be implemented in a way that achieves or optimizes one or a group of advantages without necessarily achieving other objectives or advantages.

[0117] All of these embodiments are intended to fall within the scope of the invention as disclosed herein. These embodiments and other embodiments will become apparent from the following detailed description with reference to the accompanying drawings, without limiting the invention to any specific disclosed embodiments (which may be more). Any features and / or preferred features described with reference to some embodiments can be incorporated into other embodiments in combination with other embodiments. All documents referenced herein, including patents and patent applications, are incorporated herein by reference in their entirety.

[0118] These features, aspects and advantages of the present disclosure, as well as other features, aspects and advantages, will be described with reference to drawings of several embodiments, which are intended to illustrate several embodiments but are not limiting to the present invention, and similar reference numerals in those drawings will be used for similar features. [Brief explanation of the drawing]

[0119] [Figure 1] This diagram schematically illustrates an exemplary embodiment of a launching device that directs signals from a first body cavity to a target device in a second body cavity. [Figure 2] This is a cross-sectional view along the dotted line of BB in Figure 1. [Figure 3] This diagram schematically shows an exemplary embodiment of a launching device. [Figure 4] This diagram schematically shows an exemplary embodiment of a launching device. [Figure 5]This diagram schematically shows another exemplary embodiment of the launching device. [Figure 6] This figure schematically illustrates an exemplary embodiment of a centering device for a launching device and / or a targeting device. [Figure 7] This diagram schematically shows the placement of prostheses according to procedures such as arterialization (neovascularization of arteries and veins). [Figure 8] This is a side perspective view of an exemplary embodiment of a device that provides fluid flow. [Figure 9] This diagram shows the device shown in Figure 8, which is used as a shunt between two blood vessels. [Figure 10] This is a side perspective view of another exemplary embodiment of a device that provides fluid flow. [Figure 11] This is a side perspective view of yet another exemplary embodiment of a device that provides fluid flow. [Figure 12] This is a side perspective view of yet another exemplary embodiment of a device that provides fluid flow. [Figure 13] This is a side perspective view of yet yet another exemplary embodiment of a device that provides fluid flow. [Figure 14A] This is a schematic side cross-sectional view of an exemplary embodiment of an ultrasonic emission catheter. [Figure 14B] This is an enlarged schematic side cross-sectional view of the distal portion of the ultrasound emission catheter shown in Figure 14A, within circle 14B. [Figure 15A] This is a schematic side elevation view of an exemplary embodiment of an ultrasound-targeted catheter. [Figure 15B] This is an enlarged schematic side cross-sectional view of the ultrasound target catheter shown in Figure 15A, located within circle 15B. [Figure 15C] This is an enlarged schematic side cross-sectional view of the ultrasound target catheter shown in Figure 15A, within circle 15C. [Figure 16] This figure shows an exemplary embodiment of a graph for detecting catheter alignment. [Figure 17] This is a schematic side elevation view of an exemplary embodiment of a prosthesis delivery system. [Figure 18]This is a schematic side elevation view of an exemplary embodiment of a prosthesis. [Figure 19] This is a schematic side elevation view of another exemplary embodiment of the prosthesis. [Figure 20A] This figure schematically illustrates an exemplary embodiment of a method for performing retrograde perfusion. [Figure 20B] This figure schematically illustrates an exemplary embodiment of a method for performing retrograde perfusion. [Figure 20C] This figure schematically illustrates an exemplary embodiment of a method for performing retrograde perfusion. [Figure 20D] This figure schematically illustrates an exemplary embodiment of a method for performing retrograde perfusion. [Figure 20E] This figure schematically illustrates an exemplary embodiment of a method for performing retrograde perfusion. [Figure 20F] This figure schematically illustrates an exemplary embodiment of a method for performing retrograde perfusion. [Figure 20G] This figure schematically illustrates an exemplary embodiment of a method for performing retrograde perfusion. [Figure 20H] This figure schematically illustrates an exemplary embodiment of a method for performing retrograde perfusion. [Figure 21] This is a schematic perspective view of an exemplary embodiment of an ultrasonic receiving transducer. [Figure 22] This is a schematic cross-sectional view of another exemplary embodiment of an ultrasonic receiving transducer. [Figure 23A] This is a schematic perspective view of an exemplary embodiment of a valve incision knife. [Figure 23B] This is a schematic perspective view of an exemplary embodiment of a retrograde valve incision knife. [Figure 24] This is a schematic perspective view of an exemplary embodiment of the LeMaitre apparatus. [Figure 25A] This is a schematic side elevation view of yet another exemplary embodiment of the prosthesis. [Figure 25B] This is a schematic side elevation view of yet another exemplary embodiment of the prosthesis. [Figure 25C] This is a schematic side elevation view of yet another exemplary embodiment of the prosthesis. [Figure 26A] This figure schematically illustrates another exemplary embodiment of a method for performing retrograde perfusion. [Figure 26B] This figure schematically illustrates another exemplary embodiment of a method for performing retrograde perfusion. [Figure 27] This figure schematically illustrates another exemplary embodiment of the prosthesis and a method for performing retrograde perfusion. [Figure 28A] This is a schematic diagram showing the arteries in the leg. [Figure 28B] This is a schematic diagram showing the veins in the leg. [Figure 29] This diagram schematically shows an exemplary embodiment of an anastomosis device. [Figure 30] This diagram schematically illustrates an exemplary embodiment of two blood vessels joined by an anastomosis device. [Figure 31A] This figure schematically shows an exemplary embodiment of an arteriovenous fistula stent, distinct from the exemplary embodiment of a venous stent. [Figure 31B] This diagram schematically shows an exemplary embodiment of an arteriovenous fistula stent with an integrated venous stent. [Figure 31C] This diagram schematically illustrates an exemplary embodiment of a fistula stent with an integrated venous stent. [Figure 32A] This figure shows an exemplary method and apparatus for identifying and avoiding the bifurcation 1104 in percutaneous bypass procedures. [Figure 32B] This figure shows an exemplary method and apparatus for identifying and avoiding the bifurcation 1104 in percutaneous bypass procedures. [Figure 32C] This figure shows an exemplary method and apparatus for identifying and avoiding the bifurcation 1104 in percutaneous bypass procedures. [Figure 32D] This figure shows an exemplary method and apparatus for identifying and avoiding the bifurcation 1104 in percutaneous bypass procedures. [Figure 33A] This diagram schematically illustrates an exemplary procedure in which the following connection between a first and a second blood vessel may be performed using a needle that crosses the interstitial tissue. [Figure 33B]This diagram schematically illustrates an exemplary procedure in which the following connection between a first and a second blood vessel may be performed using a needle that crosses the interstitial tissue. [Figure 34A] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 34B] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 34C] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 34D] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 34E] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 34F] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 35A] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 35B] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 35C] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 35D] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 35E] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 35F] This figure illustrates an exemplary procedure that may be performed when a guidewire is inside a blood vessel. [Figure 36A] This figure illustrates an exemplary method for promoting retrograde blood perfusion to the toes through the veins. [Figure 36B] This figure illustrates an exemplary method for promoting retrograde blood perfusion to the toes through the veins. [Figure 36C] This figure illustrates an exemplary method for promoting retrograde blood perfusion to the toes through the veins. [Figure 36D] This figure illustrates an exemplary method for promoting retrograde blood perfusion to the toes through the veins. [Figure 37A] This figure shows an example of a valve deactivation device in a radially expanded state. [Figure 37B] Figure 37A is a flattened side view of the valve deactivation device. [Figure 37C] This is an enlarged, flattened side view of the valve deactivation device in Figure 37A, in the region identified by circle 37C in Figure 37B. [Figure 37D] Figure 37B is a flattened end view of the valve deactivation device of Figure 37A. [Figure 37E] Figure 37A is an end view of the valve deactivation device in a radially contracted state. [Figure 37F] Figure 37A is a side view of the valve deactivation device in a radially contracted state. [Figure 37G] This is another side view of the valve deactivation device of Figure 37A, which is rotated circumferentially while contracted radially, compared to Figure 37F. [Figure 37H] Figure 37A is a side view of the valve deactivation device in its radially expanded state. [Figure 37I] This is another side view of the valve deactivation device of Figure 37A, which is radially expanded and circumferentially rotated compared to Figure 37H. [Figure 37J] This is a cross-sectional end view of the valve deactivation device of Figure 37A in a radially expanded state, taken along the line 37J-37J in Figure 37H. [Figure 37Ki] Figure 37A shows an exemplary procedure that can be performed using the valve deactivation device. [Figure 37Kii] Figure 37A shows an exemplary procedure that can be performed using the valve deactivation device. [Figure 37Li] Figure 37A shows an exemplary procedure that can be performed using the valve deactivation device. [Figure 37 Lii] Figure 37A shows an exemplary procedure that can be performed using the valve deactivation device. [Figure 37Mi]Figure 37A shows an exemplary procedure that can be performed using the valve deactivation device. [Figure 37 Mii] Figure 37A shows an exemplary procedure that can be performed using the valve deactivation device. [Figure 37 Ni] Figure 37A shows an exemplary procedure that can be performed using the valve deactivation device. [Figure 37Nii] Figure 37A shows an exemplary procedure that can be performed using the valve deactivation device. [Figure 38A] This diagram schematically shows an example of the distal end of a catheter.

[0120] [Figure 38B] This figure shows an exemplary procedure that can be performed using the distal end of the catheter shown in Figure 38A. [Figure 38C] This figure shows an exemplary procedure that can be performed using the distal end of the catheter shown in Figure 38A. [Figure 38D] This figure shows an exemplary procedure that can be performed using the distal end of the catheter shown in Figure 38A. [Figure 38Ei] This figure shows an example of the distal end of a catheter. [Figure 38Eii] This figure shows an example of the distal end of a catheter. [Figure 38F] This figure shows some examples of catheters. [Figure 38G] This figure shows another example of a part of a catheter. [Figure 39A] This is a perspective view of some examples of target catheters. [Figure 39B] This is a side view of the target catheter in the first state, as shown in Figure 39A. [Figure 39C] Figure 39A is a side view of the target catheter in the second state. [Figure 39D] This figure schematically illustrates an exemplary method using the target catheter shown in Figure 39A. [Figure 39E] This figure schematically illustrates an exemplary method using the target catheter shown in Figure 39A. [Figure 39F]This figure schematically illustrates an exemplary method using the target catheter shown in Figure 39A. [Figure 39G] This figure schematically illustrates an exemplary method using the target catheter shown in Figure 39A. [Figure 39H] This figure schematically illustrates an exemplary method using the target catheter shown in Figure 39A. [Figure 39I] This figure schematically illustrates an exemplary method using the target catheter shown in Figure 39A. [Figure 40A] This is a perspective view of an exemplary handle for unfolding a tubular structure. [Figure 40B] Figure 40A is an enlarged perspective cross-sectional view of a portion of the handle. [Figure 40C] Figure 40A is a perspective view of the handle in its unfolded state. [Figure 40D] This is an enlarged perspective cross-sectional view of a portion of the handle in the unfolded state shown in Figure 40A. [Figure 41A] This is a perspective view of an exemplary handle for unfolding a tubular structure. [Figure 41B] Figure 41A is a transparent, enlarged, perspective view of a portion of the handle. [Figure 41C] This figure shows an exemplary method for operating the handle in Figure 41A. [Figure 41Di] This figure shows an exemplary method for operating the handle in Figure 41A. [Figure 41Dii] This figure shows an exemplary method for operating the handle in Figure 41A. [Figure 41Ei] This figure shows an exemplary method for operating the handle in Figure 41A. [Figure 41Eii] This figure shows an exemplary method for operating the handle in Figure 41A. [Figure 41Eiii] This figure shows an exemplary method for operating the handle in Figure 41A. [Figure 42A] This is a plan view of an exemplary embodiment of a launching device. [Figure 42B] Figure 42A shows schematic top, side, and distal end perspective views of the distal portion of the launching device. [Figure 42Bi]This is a schematic side view of an exemplary radiopaque marker. [Figure 42C] Figure 42A is a schematic enlarged plan view of the distal portion of the launch device. [Figure 42Ci] This figure shows an exemplary catheter including a profile attached to a needle. [Figure 42Cii] This figure shows an exemplary catheter including a profile attached to a needle. [Figure 42Ciii] This figure shows an exemplary catheter including a profile attached to a needle. [Figure 42D] Figure 42A is a schematic side view of the distal portion of the launch device.

[0121] [Figure 43A] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43B] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43C] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43D] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43E] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43F] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43G] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43H] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43Hi] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43I] This figure schematically illustrates an exemplary method of using a launcher including the distal portion of the launcher shown in Figure 42A. [Figure 43J] This figure schematically illustrates an exemplary method of using a launcher including the distal portion of the launcher shown in Figure 42A. [Figure 43K] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43L] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43M] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43N] This figure schematically illustrates an exemplary method of using a launcher that includes the distal portion of the launcher shown in Figure 42A. [Figure 43Oi] This figure shows an example of a software-based alignment implementation. [Figure 43Oii] This figure shows an example of a software-based alignment implementation. [Figure 43Oiii] This figure shows an example of a software-based alignment implementation. [Figure 43Oiv] This figure shows an example of a software-based alignment implementation. [Figure 43Ov] This figure shows an example of a software-based alignment implementation. [Figure 43Ovi] This figure shows an example of a software-based alignment implementation. [Figure 44A] This is a schematic diagram illustrating the anatomical structure of an exemplary foot. [Figure 44B] This is a schematic diagram illustrating the anatomical structure of an exemplary foot. [Figure 44C] This is a schematic diagram illustrating the anatomical structure of an exemplary foot. [Figure 44D] This is a schematic diagram illustrating the anatomical structure of an exemplary foot. [Figure 44E] This is a schematic diagram illustrating the anatomical structure of an exemplary foot. [Figure 44F] This is a schematic diagram illustrating the anatomical structure of an exemplary foot. [Figure 45] This figure shows exemplary components of a kit that may be used for pedal access. [Figure 46A] This figure shows an exemplary procedure for performing ascending venography. [Figure 46B] This figure shows an exemplary procedure for performing ascending venography. [Figure 46C] This figure shows an exemplary procedure for performing ascending venography. [Figure 46D] This figure shows an exemplary procedure for performing ascending venography. [Figure 46E] This figure shows an exemplary procedure for performing ascending venography. [Figure 46F] This figure shows an exemplary procedure for performing ascending venography. [Figure 46G] This figure shows an exemplary procedure for performing ascending venography. [Figure 46H] This figure shows an exemplary procedure for performing ascending venography. [Figure 46I] This figure shows an exemplary procedure for performing ascending venography. [Figure 46J] This figure shows an exemplary procedure for performing ascending venography. [Figure 46K] This figure shows an exemplary procedure for performing ascending venography. [Figure 47A] A partial perspective view of an exemplary cutting snare system. [Figure 47Bi] A side view of another exemplary cutting snare system. [Figure 47Bii] A side view of another exemplary cutting snare system. [Figure 47Ci] A side view of another exemplary cutting snare system. [Figure 47Cii] A side view of another exemplary cutting snare system. [Figure 47Ciii]A side view of another exemplary cutting snare system. [Figure 47Civ] This is yet another example side view of a cutting snare system. [Figure 47Di] This is yet another example side view of a cutting snare system. [Figure 47Dii] This is yet another example side view of a cutting snare system. [Figure 47Diii] This is yet another example side view of a cutting snare system. [Figure 47Div] This is yet another example side view of a cutting snare system. [Figure 47Dv] This is yet another example side view of a cutting snare system. [Figure 47Ei] This is yet another example side view of a cutting snare system. [Figure 47Eii] This is yet another example side view of a cutting snare system. [Figure 47Eiii] This is yet another example side view of a cutting snare system. [Figure 47Eiv] A side view of another exemplary cutting snare system. [Figure 47Fi] This is yet another example side view of a cutting snare system. [Figure 47Fii] This is yet another example side view of a cutting snare system. [Figure 47Gi] This is yet another example side view of a cutting snare system. [Figure 47Gii] This is yet another example side view of a cutting snare system. [Figure 47Giii] This is yet another example side view of a cutting snare system. [Modes for carrying out the invention]

[0122] While several embodiments and examples are described below, the present invention extends beyond the embodiments and / or uses thereof, obvious modifications, and equivalents specifically disclosed herein. The scope of the present invention disclosed herein is not limited to any specific embodiment(s) described below.

[0123] Minimally invasive surgery can provide means to treat a wider range of patients, including procedures currently excluded from standard surgical techniques. One such procedure is percutaneous in situ coronary venous arterialization (PICVA), a catheter-based coronary artery bypass procedure in which an occlusion in the affected artery is "bypassed" by creating a channel between the coronary artery and an adjacent coronary vein. In this way, arterial blood can be diverted into the venous system, allowing cardiac tissue to be perfused in a retrograde manner (retrograde perfusion), and blood supply can be returned to the ischemic tissue. Several exemplary apparatuses and methods for performing procedures such as PICVA are described in PCT International Publication 99 / 049793 and U.S. Patent Application Publication 2004 / 0133225, the aforementioned PCT application and U.S. Patent application, in their entirety, constitute part of this specification by reference.

[0124] To date, successfully performing minimally invasive procedures to divert blood flow from coronary arteries to adjacent veins has often resulted in low success rates, primarily due to the inability to properly target the vein from the artery. Without appropriate systems and methods, such procedures (e.g., attempts to target veins using a combination of X-ray fluorescence and an image-forming ultrasound probe positioned at the distal tip of a catheter, as described in, for example, U.S. Patent Application Publication 2004 / 0133225) often fail before even beginning. Indeed, such configurations can be difficult to operate, and the limited location of the adjacent vein can require considerable skill from the clinician. Improvements in targeting systems and methods, such as the catheter-based systems and methods described herein, can generally enable procedures such as PICVA and transvascular surgery. Without such improvements, such percutaneous methods would remain largely insignificant compared to conventional open-heart surgery and other types of bypass surgery.

[0125] This application describes a method and system useful in minimally invasive surgery that, according to several embodiments, can reduce the workload of conventional surgery for treating conditions such as coronary heart disease and critical limb ischemia. For example, it can treat patients who would otherwise be unable to undergo surgery such as coronary artery bypass surgery or peripheral artery bypass surgery, and can reduce or significantly reduce the degree of surgical trauma, infection risk, and / or recovery time compared to conventional surgery.

[0126] Figure 1 schematically shows an exemplary embodiment of a launching device 10 that directs a signal from a first body cavity 30 to a target device 20 in a second body cavity 35. The launching device 10 comprises a signal transmitter 21. The launching device 10 may comprise, for example, a catheter having an elongated flexible rod-shaped portion and a tip portion, and may also provide a conduit for administering treatment within the patient's body. The launching device 10 may be suitable for positioning and movement through the first body cavity in the patient's body, i.e., blood vessels 30 (e.g., cardiac chambers, coronary arteries, coronary veins, peripheral arteries, peripheral veins). The elongated portion of the launching device 10 has an outer sheath 11 surrounding a space that defines a lumen 13. The space within the lumen 13 can be appropriately divided or subdivided as needed to define a channel for administering treatment, which controls the positioning of the launching device 10, etc. Such subdivision can be achieved, for example, longitudinally and concentrically in the axial direction.

[0127] The launcher 10 includes a signal transducer 12. The signal transducer 12 is configured to supply or emit a signal 40 directed outward from the launcher 10. In the embodiment shown in Figure 1, the signal 40 is directed radially outward from the launcher 10 in a direction perpendicular to the longitudinal axis of the launcher 10. As will be described in more detail below, in some embodiments the direction of the signal 40 does not have to be perpendicular to the longitudinal axis of the launcher 10, but can be directed at an angle to the longitudinal axis of the launcher 10. Thereafter, the signal transducer 12 can form at least part of the signal generating means.

[0128] The signal transducer 12 is connected to the signal transmitter 50. The signal transmitter 50 can be suitably selected from an appropriate electromagnetic source such as ultrasound, laser, microwave radiation / irradiation, or radio waves. In some embodiments, as will be described in more detail below, the signal transmitter 50 is configured to generate an ultrasonic signal, which is relayed to the signal transducer 12, which then directs the signal 40 from the first body cavity 30 into the surrounding tissue.

[0129] The target device 20 is positioned within an adjacent second body cavity in the patient's body, i.e., a blood vessel 32 (e.g., cardiac chambers, coronary arteries, coronary veins, peripheral arteries, peripheral veins). The first body cavity 30 and the second body cavity 32 are separated by interstitial tissue 34, sometimes called interstitial tissue or diaphragm. The first body cavity 30 and the second body cavity 32 are located adjacent to each other and parallel to one another for at least a portion of their respective lengths. For example, it is known that many veins and arteries in the body extend parallel to each other for at least a portion of their total length.

[0130] The target device 20 can be considered to have a configuration similar to that of the launch device 10. For example, the target device 20 may include a catheter having an elongated flexible rod-shaped portion and a tip portion. In another example, minute 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 enclosing a space that defines a lumen 23. The lumen 23 can be preferably divided, for example, as in the case of the launch device 10.

[0131] The target device 20 includes a receiving transducer 22 configured to receive a signal 40 from the transducer 12 of the launch device 10. The receiving transducer 22 constitutes at least part of the signal detection means. When in use, the receiving transducer 22, upon receiving the signal 40 transmitted from the signal transducer 12, transmits the received signal to the signal detector 60. The signal detector 60 is configured to provide an output readout to the system user, for example, via an output display 61. The output display 61 can be a visual display, an auditory display (for example, emitting a beep or some other sound when a signal is received), etc.

[0132] In this way, the transmission and detection of the directional signal 40 enables the operation and positioning of the launcher 10 relative to the target device 20. During use, the user of the system can operate the launcher 10 and the target device 20 until the output display 61 indicates that the signal 40 is being received by the target device 40.

[0133] In some embodiments, the signal 40 includes or is an ultrasonic signal. The signal 40 is directional and is emitted by the signal transducer 12 in the shape of a narrow cone or arc (for example, the signal bandwidth widens as the distance from the signal transducer 12 increases). Therefore, the accuracy of the alignment between the emitter 10 and the target device 20 depends not only on the signal detection but also on the distance between the two devices, as the signal beam width widens as the distance increases. This level of error is called "position uncertainty." There may be a certain tolerance level for position uncertainty, but the degree of uncertainty should be reduced or minimized if the treatment is to be guided accurately. For example, if the diameter d of the signal transducer 12 is 1 mm and the frequency of the ultrasonic signal is 30 MHz, the position uncertainty x (for example, the limit of error on both sides of the centerline) is 1 mm at a vertical distance of 5 mm between the emitter 10 and the target device 20. For clinical applications, positional uncertainty should generally not exceed approximately ±5 mm (with respect to a total signal beam width of 10 mm at the receiving point). In some embodiments, positional uncertainty is between approximately ±0.01 mm and approximately ±4.50 mm, or between approximately ±0.1 mm and approximately ±2 mm. In some embodiments, positional uncertainty does not exceed approximately ±1 mm.

[0134] The intensity of the signal 40 can be a factor in detection, and the signal intensity generally decreases as the distance between the emitter 10 and the target device 20 increases. This distance is determined in part by the amount of intervening tissue 34 between the devices 10 and 20. For example, if the signal 40 is an ultrasonic signal, significant signal degradation can be expected if the emitter 10 and the target device 20 are separated by solid tissue (e.g., intervening tissue 34) larger than about 20 mm. The density of the intervening tissue 34 may also affect how the signal 40 degrades over distance (e.g., denser tissue degrades the signal more than less dense tissue).

[0135] The frequency of the ultrasonic signal can also affect the thickness of the signal transducer, which is 0.075 mm at 30 MHz for a standard ultrasonic ceramic transducer (e.g., a piezoelectric transducer (PZT)).

[0136] Figure 2 is a cross-sectional view along the dotted line BB in Figure 1. Since the orientation line 41 can determine the location where treatment is administered, the correct orientation of the launcher relative to the target device can be a factor in detection. When the directional signal 40 is associated with the treatment delivery means (e.g., parallel and offset in the longitudinal direction), the clinical need to accurately place the treatment on the patient can function better. For example, in this way, the user of the system can administer treatment in the correct location by ensuring that the launcher 10 and target device 20 are correctly positioned by the transmission and reception of the signal 40. The orientation line 41 in Figure 2 indicates not only the direction but also the path of signal propagation, along which treatment can be administered to the patient.

[0137] Figure 3 schematically shows an exemplary embodiment of the launcher 10. The launcher 10 includes a signal transducer 120 oriented obliquely to the longitudinal axis of the launcher 10. The signal 40 is transmitted at a certain angle to the direction of travel of the launcher 10 (e.g., forward travel, transverse travel) as the launcher 10 enters the body cavity 30 (Figures 1 and 2). In some embodiments, the beam angle is approximately perpendicular to the longitudinal axis of the launcher 10. In some embodiments, the beam angle is between approximately 20 and 60 degrees relative to the perpendicular, between approximately 30 and 50 degrees relative to the perpendicular, or between approximately 45 degrees relative to the perpendicular, with 0 degrees corresponding to the longitudinal axis of the launcher 10 in the direction of travel.

[0138] The launching device 10 comprises a hollow needle or cannula 17, which is an exemplary means of administering treatment. During the advance of the launching device 10, the hollow needle 17 is located in a non-extended, i.e., retracted, state within the lumen 13 of the launching device 10. The hollow needle 17 can be extended / expanded from the launching device 10 through a hole 16 in the outer sheath 11 at a time deemed appropriate by the user (e.g., when the signal 40 is detected by the target device 20). The hole 16 allows for fluid communication between the lumen 13 and the body cavity 30 (Figure 1). As shown by the exemplary embodiment in Figure 3, the hollow needle 17 can advance along a path parallel to the direction of the signal 40. The hollow needle 17 can be used to puncture the intervening tissue 34 (Figure 1). In some embodiments, the hollow needle 17 traverses the entire intervening tissue 34, allowing the launching device 10 to access a second body cavity 32 (Figure 2). If desired, the pathway created by the hollow needle 17 passing through the intervening tissue 34 can later be widened to allow fluid communication between the first body cavity 30 and the second body cavity 32.

[0139] Suitable therapeutic means for use in some embodiments may include devices and / or instruments selected from the group consisting of, for example, cannulas, lasers, radiation devices, probes, drills, blades, wires, needles, and suitable combinations thereof.

[0140] In some embodiments, the hollow needle 17 is equipped with a sensor 19, which can help further determine the position 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 include temperature sensors, oxygen treatment sensors, and / or color vision sensors.

[0141] Optionally, the hollow needle 17 may be equipped with a further signal transducer 122. In the embodiment shown in Figure 3, the signal transducer 122 is positioned at one end of the guidewire 14 near the tip of the hollow needle 17. The signal transducer 122 may also be additionally or alternatively positioned on the hollow needle 17, if desired. When in use, the signal transducer 122 is driven by a short transmission pulse that generates a directional or non-directional signal pulse. The signal pulse can be detected by a receiving transducer 22 attached to the target device 20. The distance from the guidewire 14 or hollow needle 17 to the receiving transducer 22 and thus to the target device 20 can be a time that is at least partially determined based on the delay between the transmission of the signal pulse from the signal transducer 122 and the reception of the signal pulse on the receiving transducer 22 side.

[0142] Figure 4 schematically shows an exemplary embodiment of the target device 20. In the embodiment shown in Figure 4, the target device 20 is positioned within a body cavity 32. As described above, the target device 20 comprises a receiving transducer 22 that receives the signal 40. The receiving transducer 22 can be unidirectional (e.g., capable of receiving signals from only one direction) or omnidirectional (e.g., capable of receiving signals from any direction). Arrow A indicates reverse blood flow after arterial-venous angiogenesis (also known as PICVA) has been performed. The target device 20 comprises an omnidirectional ultrasonic signal receiving transducer 60. An optional reflective cone 601 can direct the signal 40 onto the disk-shaped receiving transducer 60. An acoustically transparent window 602 can separate the reflective cone 601 from the receiving transducer 60. In some embodiments, an omnidirectional ultrasonic signal receiving transducer can be obtained by positioning a cylinder of a flexible piezoelectric material such as polyvinyl difluoride (PVDF) around the outer sheath of the target device 20. In this way, the cylinder can operate in a manner similar to or equivalent to that of the receiving transducer 60.

[0143] In the embodiment shown in Figure 4, the target device 20 has an optional channel 25 used to administer drugs, such as therapeutic agents, to the patient. In some embodiments, the channel 25 functions as a conduit that allows for the application of a blocking material 251 that works to at least partially block or occlude the body cavity 32. The blocking material 251 can be appropriately selected from gel-based materials. The blocking material 251 additionally or alternatively includes an embolic member (e.g., a balloon, a self-expanding stent, etc.). The placement of the blocking material 251 can be guided by the movement of the target device 20. The presence of a guide member 24 within the lumen 23 of the target device 20 allows the user to precisely manipulate the position of the target device 20 as desired.

[0144] Referring again to Figure 2, the transmitter 10 comprises a signal transducer 12, which can be optionally oriented so that the signal 40 is transmitted at an angle other than perpendicular to the signal transducer 12. Figure 5 schematically shows another exemplary embodiment of the transmitter 10. In some embodiments, in the exemplary transmitter 10 shown in Figure 5, the signal transducer is in the form of a single transducer array 123. The signal transducer array 123 includes a plurality of signal transducer elements 124 that can be collectively oriented to define at least partially the signal beam width and angle relative to the transmitter 10. The smaller size of the elements 124 allows the signal transducer array 123 not to occupy a significant portion of the lumen 13 of the transmitter 10.

[0145] The embodiment shown in Figure 5 can be useful for ultrasonic beamforming signal transmission. Figure 5 shows an array of signal transducer elements 124 separately connected to a transmitter 50 via a delay device 51, which allows the signals to each element 124 to be delayed relative to each other. The delay device can provide or ensure that the ultrasonic waveforms from each element 124 are matched to generate an ultrasonic beam 40 at a desired angle. In some embodiments, for example, where the signal 40 includes visible light, an array of LEDs can be used additionally or alternatively.

[0146] Figure 6 schematically shows an exemplary embodiment of a centering device for the launcher 10 and / or target device 20. To assist in the process of aligning the launcher 10 in the first body cavity 30 and the target device 20 in the second body cavity 32, one or both of the devices 10 and 20 may have means for centering each device within its respective body cavity.

[0147] In some embodiments, the centering means includes an inflatable bladder or balloon 111 that is positioned within the lumen 13, 23 when undeployed and can be inflated when the devices 10, 20 reach a desired location in the patient's body. The balloon 111 can be positioned on the outer surface of the outer sheath 11, 21. The balloon 111 can be annular in shape so as to enclose the devices 10, 20 at least partially in a toroidal or donut-shaped manner. The balloon 111 can be positioned to inflate on only one side of the devices 10, 20 or on both opposing sides. As shown in Figure 6, the balloon 111 is deployed on one side of the launcher 10.

[0148] In some embodiments, the centering means includes one or more loop structures 112 positioned within the lumen 13, 23 or within recesses formed within the outer sheaths 11, 21 when in an un-expanded, i.e., contracted state. When the devices 10, 20 reach a desired location within the patient's body, one or more loop structures 112 expand radially outward from the devices 10, 20, thereby centering the devices 10, 20 within the body cavity 30, 32. The outward expansion of the loop structures 112 can be appropriately performed, for example, by compressing a wire of a certain length so as to bend outward in an arc shape from the outer sheaths 11, 21. Centering devices incorporating this stereochemical arrangement may have multiple compressible lengths of wire or other suitable flexible material arranged parallel to each other at radially spaced intervals around the outer circumference of the outer sheaths 11, 21. The compression of the multiple wires can be facilitated by sliding members (not shown) positioned proximal and / or distally near both ends of the multiple wires. The sliding members are translationally movable along the longitudinal axes of the devices 10 and 20. As shown in Figure 6, the target device 20 includes a fully deployed centering means 112 that allows the target device 20 to be centered within the body cavity 32.

[0149] Other possible means of centering the devices 10, 20 within the body cavities 30, 32 include, but are not limited to, expandable lantern-type devices, reversibly expandable stents, coils, helices, extendable probes or legs, or combinations thereof.

[0150] In some embodiments, the devices 10 and 20 can be oriented within the body cavities 30 and 32, either at the center or substantially outside the center, using centering means or other means (e.g., balloons, metal standoffs of various lengths, etc.). For example, device 10 can be oriented in the body cavity 30 close to the wall where the needle 17 exits the body cavity 30, thereby creating a shorter ultrasonic signal path and / or reducing errors, for example, due to the needle 17 traversing the intracavitary space. In another example, device 10 can be oriented in the body cavity 30 close to the wall opposite the wall where the needle 17 exits the body cavity 30, thereby creating a solid surface against which the needle 17 presses, for example. In yet another example, device 20 can be oriented in the body cavity 32 close to the wall where the needle 17 enters the body cavity 32, thereby resulting in a shorter ultrasonic signal path, for example. Other orientations of the device that are neither central nor proximal to the vessel wall are also possible (for example, being located only a portion of the diameter, such as 1 / 2, 1 / 3, 1 / 4 of the way from the wall and / or the center of the lumen).

[0151] example The methods and systems described herein demonstrate particular utility in cardiovascular surgery according to several embodiments. Several embodiments are further illustrated by the following non-limiting examples, in which the system is used by a clinician performing arteriovenous junction (PICVA) to enable retrograde perfusion of cardiac tissue after coronary artery occlusion.

[0152] The launch catheter 10 is inserted into the occluded coronary artery by standard keyhole surgery (e.g., tracking along a guidewire, tracking inside the guide catheter). The target catheter 20 is inserted into a coronary vein running parallel to the coronary artery by standard keyhole surgery (e.g., tracking along a guidewire, tracking inside the guide catheter). The coronary vein is not occluded and therefore effectively bypasses the occlusion in the coronary artery by providing an alternative channel for blood flow to the myocardium.

[0153] The launch catheter 10 comprises a PZT ultrasonic transducer 12 (for example, available from CTS Piezoelectric Products, Inc., located in New Mexico), which is oriented in this example to transmit a directional ultrasonic beam at a 45-degree angle (with respect to the longitudinal axis of the launch device), preferably in the direction of blood flow in the artery 30, but other angles, including about 90 degrees, are also possible. The ultrasonic transducer 12 is activated, and in this example, a 30 MHz directional ultrasonic signal 40 is transmitted from the launch catheter 10, but other frequencies are also possible. The target catheter 20 comprises an omnidirectional ultrasonic receiving transducer 60. To aid in the positioning of both the launch catheter 10 and the target catheter 20, both catheters 10 and 20 are equipped in this example with centering or aligning means in the form of an annular inflatable balloon 111, but other centering or aligning means are also possible, or they may be absent. The centering means 111 on the firing catheter 10 side is deployed by the clinician when the firing catheter 10 is deemed to be in the appropriate location near the occlusion site in the coronary artery 30. This can be determined by standard fluorescence imaging and / or physical resistance. The target catheter 20 is then moved into the adjacent coronary vein 32 until a directional ultrasound signal 40 is detected by the signal receiving transducer 60. To allow for more precise alignment of the firing catheter 10 and the target catheter 20, the centering means 111 on the target catheter 20 side can be deployed before or after the signal 40 is detected.

[0154] Upon receiving the transmitted signal 40, the clinician can be confident that the launch catheter 10 and target catheter 20 are correctly positioned both rotationally and longitudinally within their respective blood vessels 30, 32, and that the arterial-vein connection procedure can be initiated. Using the target catheter 20, blood flow in the coronary vein 32 can be blocked by applying the gel blocking material 251 through the channel 25 within the target catheter 20. The blocking material 251 can be applied at a location within the coronary vein 32 that is downstream of the signal receiving transducer 60 with respect to venous blood flow.

[0155] Next, the clinician can initiate arteriovenous connection by deploying a hollow needle 17 from the launch catheter 10 substantially along a path parallel to and near the path taken by the ultrasound signal 40 through the intervening tissue 34 between the coronary artery 30 and the coronary vein 32, or the hollow needle 17 can traverse a path that obstructs the ultrasound signal path at a certain point within the coronary vein 32. The hollow needle 17 is optionally equipped with a sensor 19 near its tip, which is configured to detect changes in hydrostatic pressure or Doppler flow so that the user can monitor the transition from arterial pressure to venous pressure as the hollow needle 17 passes through the two vessels 30, 32. The hollow needle 17 is optionally equipped with a guidewire 14 inside the lumen of the hollow needle 17 when deployed. Once the hollow needle 17 and guidewire 14 have traversed the intervening tissue 34, the hollow needle 17 can retract and return to the lumen 13 of the launch catheter 10, leaving the guidewire 14 in place. In some embodiments, once the hollow needle 17 has crossed the intervening tissue 34, the user can separately pass the guidewire 14 through the lumen of the hollow needle 17, thereby retracting the needle 17 into the launch catheter 10.

[0156] The clinician withdraws the launch catheter 10 from the patient, leaving the guidewire 14 in place. Next, an additional catheter device is slid along the guidewire 14. Figure 7 schematically shows a prosthesis 26, such as an expandable stent 26, in place according to procedures such as arteriovenous angiogenesis. Further details regarding possible prostheses, including stents and stent grafts, are given below. The stent 26 can be deployed to widen the perforation in the intercalated tissue 34 between the coronary artery 30 and the coronary vein 32, where the intervening arrow A indicates the direction of blood flow through the stent 26 between the first body cavity 30 and the second body cavity 32 (for example, by passing through the stent 26 in this way, arterial blood can bypass the venous system and retrograde perfuse the myocardial tissue). The stent 26 blocks upstream flow in the body cavity 32, allowing blood flow in the body cavity 32 to flow in the same direction as blood flow in the body cavity 30. The graft material of the stent 26 can form a liquid-tight lumen between body cavities 30 and 32. The target catheter 20 is withdrawn from the patient, leaving the block material 251 in place. Optionally, as further detailed herein, additional blocks or sutures may be inserted into the coronary vein to block or prevent backflow of arterial blood.

[0157] While the specific examples described above relate to cardiovascular surgery, the methods and systems described herein can have broad applications in other forms of surgery. For example, any surgery requiring the delivery of treatment from one body cavity to another adjacent body cavity (e.g., for the treatment of peripheral artery disease) can be considered. Such applications may also be found in the fields of neurosurgery, urology, and general vascular surgery. Depending on the type of treatment, it is not necessary to restrict the formation of inter-body cavity channels. For example, the methods and systems described herein can also be used to deliver techniques such as catheter ablation, non-contact mapping of cardiac chambers, and precise drug delivery to specific locations in the body.

[0158] Several techniques for effectively bypassing arterial occlusions via percutaneous surgery are described above. These techniques involve creating a channel or passage between a first passage, such as an artery, vein, or cardiac chamber upstream of the occlusion, and a second passage, such as an artery, vein, or cardiac chamber adjacent to the first passage, and interconnecting the first and second passages by a third passage. Fluids such as blood can be diverted from the first passage to the second passage by the third interconnecting passage. In embodiments where the first passage includes an artery and the second passage includes a vein, arterial blood can be perfused retrogradely into the tissue (retrograde perfusion).

[0159] As described above, the interconnection passage between the first and second body cavity passages can be created, for example, by deploying a needle outward from a first catheter positioned within the first passage, thereby traversing the interstitial tissue, or diaphragm, between the first and second passages. A second catheter, providing a target device for receiving signals transmitted from the first catheter, such as ultrasonic signals, can be positioned in the second passage. By monitoring the received signals, the position of the first catheter relative to the second catheter can be determined to ensure that the needle deploys in the correct position and orientation to create a passage for fluid flow between the first and second passages.

[0160] To provide or maintain blood flow through interconnection passages, i.e., interconnection channels, a structure having a lumen can be inserted into the passage to support interstitial tissue and / or prevent or block the passage from closing. The tubing may include, for example, a stent that is expanded in the channel using a balloon catheter, as described herein, or a self-expanding stent. A catheter for delivering the structure, such as a balloon catheter or a self-expanding catheter, can be guided into the channel by a guidewire deployed in the passage by a first catheter.

[0161] Arteries, veins, and cardiac chambers can pulsate when the heart beats, for example, due to the movement of the heart wall, the movement of the peripheral limbs, and / or fluctuations in pressure within the passages themselves. This pulsation can cause the passages to move relative to each other, which can stress structures within the interconnecting passages between them. This stress can be greater than the stress experienced by structures within a single passage. This stress can lead to premature failure of structures, for example, fatigue failure of stent struts. Failure of structures can result in damage to interstitial tissue and / or occlusion of interconnecting passages, which can lead to significant complications or complete failure of treatment.

[0162] Figure 8 shows a device, i.e., an implant or prosthesis 100, that provides or maintains fluid flow through at least one passage. The device 100 has a first end portion, i.e., a proximal end portion 102, a second end portion, i.e., a distal end portion 104, and an intermediate portion 106 between the proximal end portion 102 and the distal end portion 104. The device 100 has a lumen, i.e., a tube 110 through which fluid flows. The device 100, for example, at least the intermediate portion 106 of the device 100, includes a flexible polymer tube 108. The flexible polymer tube can at least partially define the tube 110.

[0163] The device 100 has a support structure (e.g., at least one stent) including meshes 112 and 114. In some embodiments, at least a portion of mesh 112 is embedded in the outer wall of the tube 108 in close proximity to the proximal end portion 102 of the device 100. In some embodiments, at least a portion of mesh 114, for example, wire or strut, is embedded in the outer wall of the tube 108 in close proximity to the distal end portion 104 of the device 100. The meshes 112 and 114 may include biocompatible metals such as stainless steel and / or shape memory materials such as nitinol or cobalt-chromium.

[0164] The wire meshes 112 and 114 can stiffen the end portions 102 and 104, respectively. In some embodiments where the intermediate portion 106 does not contain mesh, the intermediate portion 106 can be relatively more flexible than the end portions 102 and 104, and / or the end portions 102 and 104 can have relatively high radial rigidity.

[0165] In some embodiments, the end portions 102, 104 of the device 100 are expandable in the diametrical direction. For example, the wire meshes 112, 114 may have a diameter smaller than the passage through which the device 100 unfolds, such as a blood vessel, after formation, i.e., after manufacturing. When the device 100 is in a predetermined position within the passage, the end portions 102, 104 can be expanded, i.e., deformed outward, thereby increasing the diameter of each end portion 102, 104 so that they abut, for example, the inner side wall of the passage. The end portions 102, 104 are configured to be maintained indefinitely at their expanded diameter by plastic deformation of the material of the mesh 112, 114 (e.g., wire, strut) and / or by measures of a locking mechanism arranged to mechanically lock the mesh 112, 114 in the expanded position. The middle portion 106 of the device 100 can be made expandable in the diametrical direction by plastic deformation of, for example, a tube 108.

[0166] Figure 9 shows the apparatus 100 of Figure 8 deployed to provide a fluid flow path between a first passage 116 and a second passage 118. The passages 116 and 118 may include coronary vessels, e.g., coronary arteries 116 and coronary veins 118, or vice versa, coronary veins 116 and coronary arteries 118. The passages 116 and 118 may also include peripheral vessels (e.g., vessels in the limbs), e.g., femoral artery or other peripheral artery 116 and femoral vein or other peripheral vein 118, or vice versa, femoral vein or other peripheral vein 116 and femoral artery or other peripheral artery 118. The end portions 102, 104 and the intermediate portion 106 of the apparatus 100 expand to merge with and press against the inner walls of the passages 116 and 118. The distal end portion 104 of the device 100 is located within the second passage 118, and the proximal end portion 102 of the device 100 is located within the first passage 116. The intermediate portion 106 extends through an opening, or interconnection passage 130, surgically formed between passages 116 and 118.

[0167] The extended end portions 102 and 104 of the device 100 are elastic and exert outward radial forces on the inner walls of the passages 116 and 118. The radial rigidity of the end portions 102 and 104 of the device 100 holds or fixes them in place within the respective passages 116 and 118. This prevents or reduces displacement of the device 100 within the passages 116 and 118. In this way, the end portions 102 and 104 of the device 100 can fix or secure the device 100 in place while providing or maintaining fluid flow through the lumen 110 of the tube 108 (Figure 8) during use. In this way, the device 100 can act as a shunt between the first passage 116 and the second passage 118.

[0168] The intermediate portion 106 of the device 100 can be made flexible, for example, allowing the intermediate portion 106 to form an "S" shape by combining the first passage 116, the second passage 118, and the interconnecting passage 130 (Figure 9). The flexible intermediate portion 106 allows the end portions 102 and 104 of the device 100 to move relative to each other in accordance with the relative movement of the passages 116 and 118.

[0169] In embodiments in which the intermediate portion 106 does not contain wire mesh but includes the flexible polymer material of the tube 108, the intermediate portion 106 can be made less susceptible to damage caused by mesh fatigue due to periodic stress or other stresses, for example, that are imparted by the relative movement of the passages 116 and 118.

[0170] The intermediate portion 106 of the device 100 has sufficient elasticity to maintain the expansion of the interconnection passage 130, so that the interconnection passage 130 remains open to provide or maintain a pathway for blood flow from artery 116 to vein 118 through the lumen 110 of tube 108 (Figure 8). This allows blood flow from artery 116 to vein 118 through the interconnection passage 130 to be provided or maintained through the lumen 110 of tube 108. The device 100 at least partially supports artery 116, vein 118 and interconnection passage 130 to provide a pathway for fluid communication through the device 100.

[0171] The proximal end portion 102 and distal end portion 104 of the device 100 are configured such that, when the distal end portion 104 of the device 100 is deployed in a vein 118 and the proximal end portion 102 of the device 100 is deployed in an artery 116, for example as shown in Figure 9, the diameter of the expanded distal end portion 104 is sufficient to hold the distal end portion 104 in the vein 118, and the diameter of the expanded proximal end portion 102 is sufficient to hold the proximal end portion 102 in the artery 116. Therefore, the diameter of the proximal end portion 102 can be different from the diameter of the distal end portion 104. By selecting appropriate diameters for the end portions 102, 104 and the intermediate portion 106, the device 100 can be manufactured to fit a particular anatomical structure and / or the anatomical structure of an individual patient.

[0172] As shown for example in Fig. 9, an exemplary procedure for positioning the device 100 of Fig. 8 to provide a shunt between an occluded artery 116 and vein 118 (e.g., between a coronary artery 116 and coronary vein 118, or between a peripheral artery 116 and peripheral vein 118) to achieve retrograde perfusion of arterial blood is described herein.

[0173] A catheter can be inserted into a patient's arterial system, typically through a small incision made in the patient's groin region. The catheter is delivered to the artery 116 and guided to a position upstream of the occlusion site, for example, at a location proximate to the vein 118, parallel or substantially parallel to the vein 118. A hollow needle is deployed from the catheter, passed through the wall of the artery 116, through the interstitial tissue 132 separating the artery 116 and the vein 118, and through the wall of the vein 118. This path of the needle creates an interconnecting passage or opening 130 that allows blood to flow between the artery 116 and the vein 118. Needle deployment can be guided, for example, as described herein, by a transmitter connected to a catheter in the artery 116 (e.g., a directional ultrasound transmitter) and a receiver connected to a catheter in the vein 118 (e.g., an omnidirectional ultrasound receiver), or conversely by a receiver connected to a catheter in the vein 118 and a transmitter connected to a catheter in the artery 116, and can be guided as set forth in U.S. Patent Application No. 11 / 662,128. Other methods of forming the opening 130 are also contemplated (e.g., using other types of guides as described herein from vein to artery, whether or not directional ultrasound guidance is employed, etc.).

[0174] Before withdrawing the hollow needle from the passage 130, a guidewire (e.g., as described with respect to guidewire 14 in Fig. 3) is inserted through the needle and into the vein 118. The needle is then retracted while leaving the guidewire in place within the artery 116, the passage 130, and the vein 118. The catheter carrying the needle can then be withdrawn from the patient's body. The guidewire can be used to further guide a catheter into the interconnecting passage 130 between the artery 116 and the vein 118.

[0175] The catheter carrying the unexpanded device 100 is advanced toward the interconnecting passage 130 while guided by a guide wire, for example via a rapid exchange lumen or through the lumen 110. The catheter can comprise, for example, a balloon catheter configured to expand at least a portion of the device 100 and / or a catheter configured to allow self-expansion of at least a portion of the device 100. A distal end portion 104 of the device 100 passes through the interconnecting passage 130 into the vein 118, while a proximal end portion 102 remains in the artery 116. A middle portion 106 of the device 100 is located at least partially within the passage 130, and at least partially within the artery 116 and the vein 118. The middle portion 106 bends to assume a curved configuration, that is, an "S"-shaped configuration, depending on the anatomy of the relevant site. By assuming such a curvature, the shape of the middle portion 106, which optionally extends through the interconnecting passage 130 and into the interior of at least one of the passages 116 and 118, can conform at least to the shape of the interconnecting passage 130.

[0176] The distal end portion 104 of the device 100 is expanded, for example by balloon inflation or self-expansion, to increase the diameter of the distal end portion 100 and anchor the distal end portion 104 against the inner wall of the vein 118. The catheter can be adapted to expand the middle portion 106 of the device 100, for example by balloon inflation, thereby opening or enlarging the interconnecting passage 130 to obtain blood flow (e.g., sufficient blood flow) from the artery 116 to the vein 118. The proximal end portion 102 of the device 100 is expanded, for example by balloon inflation or self-expansion, to increase the diameter of the proximal end portion 102 and anchor the proximal end portion 102 against the inner wall of the artery 116.

[0177] For example, after expanding the end portions 102, 104 of the device 100 by self-expansion and / or balloon expansion, the catheter and guidewire are withdrawn from the patient's body, whether or not the post-deployment expansion is increased. In this way, the device 100 is placed or fixed in a predetermined position within the vein 118, artery 116 and interconnection passage 130, as shown in Figure 9. In embodiments in which the device 100 includes a stent graft, the graft can form a liquid-tight passage between artery 116 and vein 118, thereby blocking such passage and thus preventing or inhibiting the anterograde flow of blood in vein 118, and the graft can be additional or alternative to the blocking material in vein 118.

[0178] The catheter can be adapted to selectively inflate the proximal end portion 102, distal end portion 104, and / or intermediate portion 106 of the device 100 individually or in combination, by means of, for example, two or more separate inflatable balloons or balloon portions, a single balloon configured to inflate all portions of the device 100 simultaneously, or a single balloon configured to inflate one or more selected portions of the device 100. For example, the end portions 102 and 104 can be self-inflating, and the intermediate portion 106 can be inflated by a balloon to enlarge the passage 130. In some embodiments including balloon inflation, all or selected portions of the device 100 can be inflated, for example, simultaneously by a balloon along the entire length of the device 100, or by multiple longitudinally spaced balloons to selectively inflate selected portions of the device 100, and / or sequentially by one or more balloons. In some embodiments, including at least partial self-expansion, all or selected portions of the device 100 can be expanded, for example, by retracting a sheath covering or surrounding the device 100 proximal to the side, thereby allowing the device 100 to unfold distally as the sheath retracts proximal to the side. It is also possible to unfold the device 100 proximal to the side, and to unfold the device 100 first from the middle and then to both ends. In some embodiments, for example, in embodiments where the device 100 is at least partially conical or tapered, the device 100 can be expanded at least partially using a conical or tapered balloon. In some such embodiments, the portion of the balloon closest to the vein 118 may have a larger diameter than the portion of the balloon closest to the artery 116, so that, for example, the device 100 can change the diameter of the vein in response to any increase in pressure or blood flow within the vein 118.

[0179] Other steps may be included in the procedure. For example, before deploying the device 100, the balloon catheter can be guided into the interconnection passage 130 and positioned so that the inflatable balloon portion of the catheter is inside the interconnection passage 130. When the balloon inflates, it presses against the wall of the interconnection passage 130, widening, or expanding, the interconnection passage 130, thereby facilitating the subsequent insertion of the device 100.

[0180] Figure 10 shows another apparatus 134 that provides fluid flow through at least one passage. Apparatus 134 has a mesh 136 and a polymer tube 108. The mesh 136 is shown as being outside the polymer tube 108, but additionally or alternatively, as described herein, it may be inside and / or within the polymer tube 108. As described with respect to apparatus 100, apparatus 134 has a proximal end portion 102, a distal end portion 104, and an intermediate portion 106. In the embodiment shown in Figure 10, the mesh 136 extends along the entire length of apparatus 134, including along the intermediate portion 106.

[0181] In some embodiments, the spacing of the filaments or struts of the mesh 136 varies along the length of the apparatus 134. For example, the winding density of the woven filament mesh or the layered filament mesh can vary, and / or the window size pattern of the cut mesh can vary.

[0182] In some embodiments, the spacing can be relatively small in the proximal end portion 102 and the distal end portion 104, and relatively large in the intermediate portion 106. In other words, the density or window size of the mesh 136 can be relatively small in the intermediate portion 106 and relatively large in the end portions 102 and 104. In some such embodiments, the intermediate portion 106 can be more flexible than the end portions 102 and 104. The relatively rigid end portions 102 and 104 can engage with the passage and remain within it. The mesh 136 in the intermediate portion 106 may be subjected to stresses such as cyclic stress during use, but because the intermediate portion 106 has relatively high flexibility due to its lower density or window size, the intermediate portion 106 can bend in response to stress, thus reducing the impact of the stress. Therefore, the risk of fatigue failure of the apparatus 134, in particular the filaments or struts 138 of the mesh 136, can be reduced compared to an apparatus with uniform flexibility along its entire length.

[0183] In some embodiments, the spacing can be relatively large in the proximal end portion 102 and the distal end portion 104, and relatively small in the intermediate portion 106. In other words, the density of the mesh 136 can be relatively high in the intermediate portion 106 (or the window size of the mesh 136 can be relatively small), and relatively small in the end portions 102 and 104 (or the window size of the mesh 136 can be relatively large). In some such embodiments, the intermediate portion 106 can have sufficient radial rigidity to prevent or stop the collapse of the passage 130, but can still have sufficient flexibility to deflect in response to stresses such as cyclic stress. The end portions 102 and 104 can engage with the passage and remain within it.

[0184] Figure 11 shows another device, i.e., an implant or prosthesis 140, that provides fluid flow through at least one passage. As described with respect to device 100, device 140 has a proximal end portion 102, a distal end portion 104, and an intermediate portion 106. Device 140 comprises a polymer tube 108 and a support structure having a first mesh 142 and a second mesh 144. The first mesh 142 extends from the proximal end portion 102 toward the intermediate portion 106 (e.g., into the intermediate portion 106), and optionally into the distal end portion 104. The second mesh 144 extends from the distal end portion 104 toward the intermediate portion 106 (e.g., into the intermediate portion 106), and optionally into the proximal end portion 102. Thereafter, the meshes 142 and 144 overlap each other at least in the intermediate portion 106. Both meshes 142 and 144 can be located outside the tube 108, inside the tube 108, or embedded inside the tube 108; or one mesh can be located outside the tube 108, inside the tube 108, or embedded inside the tube 108, while the other mesh can be located outside the tube 108, inside the tube 108, or embedded inside the tube 108 in a different manner than the other mesh (for example, one mesh may be inside the tube 108 and the other mesh may be outside the tube 108). Meshes 142 and 144 can be formed, for example, by braiding wires in a grid configuration around or inside the polymer tube 108, by arranging cut pipes around or inside the polymer tube 108, by embedding them inside the polymer tube 108, or by a combination thereof.

[0185] In some embodiments, the density of meshes 142 and 144 is relatively high at their respective end portions 102 and 104 (i.e., the window size of meshes 142 and 144 is relatively small), and decreases toward the middle portion 106 (i.e., the window size increases). The overall braid density (e.g., the braid density of both meshes 142 and 144 combined) can be lower in the middle portion 106 than at the end portions 102 and 104, i.e., the overall window size (e.g., the window size of both meshes 142 and 144 combined) can be larger in the middle portion 106 than at the end portions 102 and 104. In some such embodiments, the middle portion 106 is relatively more flexible than the end portions 102 and 104. In some embodiments, the meshes 142 and 144 do not extend into the middle portion, and the absence of mesh in the middle portion 106 can make it relatively more flexible than the end portions 102 and 104. In some embodiments, as the window size increases (for example, longitudinally along the tapered portion of the apparatus 140), the density decreases, the mesh coverage decreases, and / or the porosity increases, because the width of the struts and / or filaments is substantially constant or constant, or does not increase at the same rate as the window size, which can result in a change in flexibility along the longitudinal length.

[0186] The first mesh 142 and the second mesh 144 can contain various materials, which allows for the optimization of the respective properties of each distal end portion 102 and proximal end portion 104 of the device 140 for a specific application of the device 140. For example, the second mesh 144 in the distal end portion 104 of the device 140 may contain a relatively flexible metal alloy to facilitate insertion into the interconnection passage between two blood vessels, while the first mesh 142 in the proximal end portion 102 of the device 140 may contain a relatively inelastic metal alloy to provide a high degree of resistance to the proximal end portion 104 in order to firmly secure the device 140 in place. The first mesh 142 and the second mesh 144 may have the same material composition (e.g., both containing nitinol) but different wire diameters (gauges) or strut thicknesses.

[0187] Figure 12 shows another device, i.e., an implant or prosthesis 150, that provides fluid flow through at least one passage. Device 150 has a support structure (e.g., a stent) 152 and a graft 154. As described with respect to device 100, device 150 has a proximal end portion 102, a distal end portion 104, and an intermediate portion 106. The proximal end portion 102 has a cylindrical or substantially cylindrical portion, and the distal end portion 104 has a cylindrical or substantially cylindrical portion. The diameter of the proximal end portion 102 is smaller than the diameter of the distal end portion 104. In some embodiments, the diameter of the proximal end portion 102 is larger than the diameter of the distal end portion 104. The intermediate portion 106 has a tapered or frustoconical shape between the proximal end portion 102 and the distal end portion 104. The stent 152 may include filaments (e.g., woven, layered), cut tubes or cut sheets and / or combinations thereof.

[0188] The parameters of the stent 152 may be uniform or substantially uniform across one and / or more of its portions, or may vary within one and / or between multiple portions. For example, the stent 152 may include a cut tube or cut sheet in the proximal end portion 102, the stent 152 may include a cut tube or cut sheet in the distal end portion 102, and the stent 152 may include a filament (e.g., woven or layered) in the intermediate portion 106. Some such embodiments can provide excellent implantation with the proximal end portion 102 and the distal end portion 104, and excellent flexibility of the intermediate portion 106 (e.g., adaptability to the size of the third passage and dynamic stress).

[0189] Stent 152 can contain various materials in various parts. For example, stent 152 may contain cobalt-chromium and / or tantalum in the proximal end portion 102, stent 152 may contain nitinol in the distal end portion 104, and stent 152 may contain nitinol in the intermediate portion 106. Some such embodiments can result in excellent placement and / or wall juxtaposition by the device 150 in each deployment area (e.g., the proximal end portion 102 engaging with the side wall of an artery, the distal end portion 104 engaging with the side wall of a vein, and the intermediate portion 106 engaging with the side wall of the passage between the artery and the vein). In some embodiments where the distal end portion 104 is self-expanding, the distal end portion 104 can be adapted by changing the vessel diameter, for example by further self-expansion, if the vein diameter increases due to increased pressure or blood flow.

[0190] Combinations of materials and types for the support structure are also possible. For example, the stent 152 may include a cut tube or cut sheet containing cobalt-chromium and / or tantalum in its proximal portion, a cut tube or cut sheet containing nitinol in its distal end portion 104, and a filament containing nitinol in its intermediate portion 106.

[0191] In embodiments, the stent 152 has at least one portion including a cut tube or cut sheet, and the cut pattern may be the same. For example, the cut pattern may be the same in the proximal end portion 102 and the distal end portion 104, but is proportional to the change in diameter. In some embodiments, the window size or strut density is uniform or substantially uniform within portions 102, 104, and 106, within two or more of portions 102, 104, and 106, and / or from one end of the stent 152 to the other end of the stent 152. In embodiments in which the stent 152 has at least one portion including a filament, the winding may be the same. For example, the winding may be the same in the proximal end portion 102 and the distal end portion 104, but varies with the change in diameter. In some embodiments, the winding density or porosity is uniform or substantially uniform within portions 102, 104, 106, within two or more portions 102, 104, 106, and / or from one end of the stent 152 to the other end. In embodiments in which the stent 152 has at least one portion comprising a cut tube or cut sheet and at least one portion comprising a filament, the cut pattern and winding may be configured to obtain a uniform or substantially uniform density. Non-uniformity may also be possible, for example, as described herein.

[0192] Graft 154 may include the same material as described for tube 108 and an attachment to stent 152. Graft 154 generally forms a liquid-tight passage for at least a portion of the device 150. Although graft 154 is shown as being only around the intermediate portion 106, it may extend along the entire length of the device 150 or partially overlap in at least one of the cylindrical end portions 102, 104.

[0193] Figure 13 shows another device 160 that provides fluid flow through at least one passage. Device 160 has a support structure (e.g., a stent) and a graft 164. As described with respect to device 100, device 160 has a proximal end portion 102, a distal end portion 104, and an intermediate portion 106. The proximal end portion 102 has a tapered or frustoconical portion, and the distal end portion 104 has a tapered or frustoconical portion. The diameter of the proximal end of the proximal end portion 102 is smaller than the diameter of the distal end of the distal end portion 104. In some embodiments, the diameter of the proximal end of the proximal end portion 102 is larger than the diameter of the distal end of the distal end portion 104. The intermediate portion 106 has a tapered or frustoconical shape between the proximal end portion 102 and the distal end portion 104. In some embodiments, the inclination angles of portions 102, 104, and 106 are the same or substantially the same (as shown, for example, in Figure 13). In some embodiments, the inclination angle of at least one portion is sharper, i.e., narrower than at least one of the other portions. The frustoconical proximal end portion 102 and distal end portion 104 can allow for better placement within the internal passage, for example, because arteries taper as they move away from the heart and veins taper as they move towards the heart, and the end portions 102, 104 can be configured to at least partially correspond to such anatomical tapers.

[0194] FIG. 12 shows an apparatus 150 having a first cylindrical or straight portion, a conical or tapered portion, and a second cylindrical or straight portion. FIG. 13 shows an apparatus 160 having one or more conical or tapered sections (e.g., the entire apparatus 160 is conical or tapered, or has a plurality of conical or tapered sections). In some embodiments, combinations of apparatuses 150, 160 are contemplated. For example, the apparatus may have a cylindrical or straight portion, and the remaining portion of the apparatus may have a conical or tapered portion. In some such embodiments, the apparatus can have a length of from about 1 cm to about 10 cm (e.g., about 5 cm), with a cylindrical or straight portion having a diameter of from about 1 mm to about 5 mm (e.g., about 3 mm) and a length of from about 0.5 cm to about 4 cm (e.g., about 2 cm), and a conical or tapered portion having a diameter that gradually increases from the diameter of the cylindrical or straight portion to from about 3 mm to about 10 mm (e.g., about 5 mm) and a length of from about 1 cm to about 6 cm (e.g., about 3 cm). Such an apparatus may not have another subsequent cylindrical portion or conical portion.

[0195] As discussed above with respect to support structure 152, support structure 162 can comprise filaments (e.g., woven, layered), cut tubes or cut sheets, the same material, different materials, and combinations thereof.

[0196] Graft 164 can comprise materials as described for tube 108 and attachment to stent 162. Graft 164 generally forms a fluid-tight passageway for at least a portion of apparatus 160. Although graft 164 is shown as being only around intermediate portion 106, it may extend the entire length of apparatus 160, or partially overlap into at least one of frustoconical end portions 102, 104.

[0197] In some embodiments, a combination of apparatus 150 and apparatus 160 is possible. For example, the proximal end portion 102 may be cylindrical or substantially cylindrical (as in apparatus 150), and the distal end portion 104 may be tapered or frustoconical (as in apparatus 160), with the proximal end portion 102 having a larger diameter than the distal end of the distal end portion 104. In another example, the proximal end portion 102 may be tapered or frustoconical (as in apparatus 160), and the distal end portion 104 may be cylindrical or substantially cylindrical (as in apparatus 150), with the proximal end of the proximal end portion 102 having a larger diameter than the distal end portion 104. In each example, the intermediate portion 106 may have a tapered or frustoconical shape between the proximal end portion 102 and the distal end portion 104.

[0198] Exemplary deployment devices for implantable devices described herein are described in U.S. Patent Application No. 12 / 545982, filed August 24, 2009, and U.S. Patent Application No. 13 / 486249, filed June 1, 2012, the entire contents of each of those U.S. Patent Applications, respectively, constitute part of this specification by reference. The device generally has, at its proximal end, a handle with a trigger that can be activated by a user, and at its distal end, a combination of tubular members configured to be pushed and / or pulled when the trigger is activated to release the device. Other delivery devices are also conceivable. The delivery device may have a portion that can slide along a guidewire (e.g., manipulated between arteries and veins by a tissue-crossing needle) and / or be traceable through the lumen of a catheter.

[0199] While several embodiments and examples have been described in detail herein, various combinations, partial combinations, modifications, alterations, substitutions, and omissions of the specific features and aspects of these embodiments are conceivable, but only a portion of them are described here as mere examples.

[0200] The device, such as the device's stent, mesh, and support structure, can be self-expanding. For example, the mesh may include a shape-memory material, such as nitinol, that can return to a preset shape after deformation. In some embodiments, the stent may be fabricated to a desired shape in its expanded form and is compressible to fit inside a sleeve so as to be delivered to a vascular site through a catheter. To deploy and expand the stent, the sleeve is retracted from the stent, allowing the shape-memory material to return to its preset shape, thereby allowing the stent to be placed in the passage and, if the stent has sufficient radial strength, to expand the passage. The use of a balloon catheter is not required to expand a fully self-expanding stent, but can be used, for example, to enhance or optimize deployment.

[0201] The device may have one or more self-expanding parts and one or more parts that can be expanded by deformation, for example, using a balloon catheter. For example, in the embodiment shown in Figure 11, the first mesh 142 may contain stainless steel that can be expanded by a balloon catheter, and the second mesh 144 may contain nitinol to self-expand during expansion.

[0202] In any embodiment described herein, the polymer tube 108 having grafts 154, 164 may contain any suitable compliant or flexible polymer, such as polyurethanes, combinations thereof, including PTFE, silicone, polyethylene terephthalate (PET), polycarbonate-based aromatic bio-durable thermoplastic polyurethane elastomers (e.g., ChronoFlex C® 80A and 55D medical grade, available from AdvanSource Biomaterials, Inc., Wilmington, Massachusetts), etc. The polymer tube 108 may contain biodegradable polymers, bioabsorbable polymers, or biocompatible polymers (e.g., polylactic acid (PLA), polyglycolic acid (PGA), polyglycol lactic acid (PLGA), polycaprolactone (PCL), polyorthoesters, polyanhydrides, etc.). The polymer may be in tubular form before interacting with a support structure (e.g., a stent), or may be formed on, inside, and / or around a support structure (e.g., a stent). For example, the polymer may contain spun fibers, dipped coatings, combinations thereof, etc. In some embodiments, for example, when the device is to be deployed in a single blood vessel, the device may omit a tube. In some such embodiments, the middle portion of the stent may have a mesh with a low winding density or a high window size, while the end portion of the stent may have a mesh with a higher winding density or a lower window size, and the mesh is generally tubular so as to define a path for fluid flow through the center of the mesh. In some embodiments, the polymer tube 108 has a lip (for example, made of the same or different material) which can help form a liquid-tight seal between the polymer tube 108 and the internal passage. The seal may be angled, for example, for oblique positioning of the polymer tube 108 between internal passages. In some embodiments, the polymer tube 108 may extend longitudinally beyond the support structure in at least one direction, and the portion extending beyond the support structure is supported by the support structure.

[0203] The mesh may contain any suitable material such as nickel, titanium, chromium, cobalt, tantalum, platinum, tungsten, iron, manganese, molybdenum, or combinations thereof (e.g., nitinol, cobalt-chromium, stainless steel). The mesh may contain biodegradable polymers, bioabsorbable polymers, or biocompatible polymers (e.g., polylactic acid (PLA), polyglycolic acid (PGA), polyglycol lactic acid (PLGA), polycaprolactone (PCL), polyorthoesters, polyanhydrides, or combinations thereof) and / or glass, and may not contain metal. Various materials may be used in some parts of the mesh or within the same mesh, as described above with reference to Figure 11, for example. For example, mesh 114 in the distal end portion 104 and mesh 112 in the proximal end portion 102 of the apparatus 100 may contain different materials. In another example, mesh 112 and / or mesh 114 may include various 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, metal alloys combined with cladding materials (e.g., including a core containing radiopaque materials such as titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, etc.)) (e.g., cobalt, chromium, nickel, titanium, combinations thereof, 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 of meshes 112, 114 includes nitinol and stainless steel. Nitinol can enable some self-expansion (e.g., partial self-expansion and / or complete self-expansion), in which case the mesh can be further expanded, for example, using balloons.

[0204] While woven filament meshes are generally shown in Figures 8, 10, and 11, any other structures capable of providing the desired elasticity may be used. For example, layers of filaments wound in opposite directions can be melted at both ends of the filaments to provide an expandable structure. In another example, a metal sheet may be cut (e.g., laser cutting, chemical etching, plasma cutting, etc.) to form perforations, which are then heat-set within a tubular structure, or a metal tube (e.g., a hypo tube) may be cut (e.g., laser cutting, chemical etching, plasma cutting, etc.) to form perforations. The cut tube (including a cut sheet wound into a tube) can be heat-set to give it an expandable form.

[0205] Filaments, wires, or ribbons, which can be woven, braided, layered, or otherwise constructed, are generally elongated and have cross-sections such as circular, elliptical, square, or rectangular. An exemplary nonwoven filament may have a first filament layer wound in a first direction and a second filament layer wound in a second direction, with at least a portion of the filament ends joined together (for example, by joining them to an expandable ring). Exemplary braiding patterns include one filament above and one below, one filament above and two above, two filaments above and two above, and / or combinations thereof, but other braiding patterns are also conceivable. At filament intersections, the filaments may be wound spirally, intersect in a sliding relationship, and / or combinations thereof. The filaments may be loose (for example, joined together by braiding), and / or join elements such as welds, sleeves, and / or combinations thereof. The ends of the filament can be curved and crimped to a ring (for example, by crimping the ends with a radiopaque material such as titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, etc., which can also act as a radiopaque marker), twisted, ball-welded, or a combination thereof. The woven edge may include filament ends and / or curved filaments and may have open bubbles, fixed or unfixed filaments, welds, adhesives or other melting means, radiopaque markers, or a combination thereof. The parameters of the filament may be uniform or substantially uniform across one and / or more parts, or may vary within one and / or between multiple parts. For example, the proximal end portion 102 may have a first parameter, and the distal end portion 104 may have a second parameter different from the first braid pattern. In another example, the proximal portion 102 and the distal portion 104 may each have a first parameter, and the intermediate portion 106 may have a second parameter different from the first parameter. In yet another example, at least one of the proximal portion 102, the distal portion 104, and the intermediate portion 106 may have both a first parameter and a second parameter different from the first parameter.Filament parameters may include, for example, filament type, filament thickness, filament material, amount of filament, weave pattern, lamination, winding direction, pitch, angle, cross type, filament bonding or absence thereof, filament end treatment, weave end treatment, lamination end treatment, amount of layer, presence or absence of welds, radiopaqueness, braid pattern, density, porosity, filament angle, braid diameter, winding diameter, and shape setting.

[0206] A tube or sheet can be cut to form a strut pattern or a cell pattern, where struts are the remaining portion of the tube or sheet after cutting, and cells, perforations, or windows are the separated portions. A tube (e.g., a hypo tube) may be cut directly, or a sheet may be cut and then rolled into a tube. The tube or sheet may have a shape set before or after cutting. The tube or sheet may be welded or otherwise bonded to itself, another tube or sheet, a filament, a graft material, etc. Cutting may be done by laser, chemical etching solution, plasma, a combination thereof, etc. Exemplary cut patterns include spiral, woven, coiled, individual rings, continuous rings, open-cell, closed-cell, and combinations thereof. In embodiments including continuous rings, the rings can be connected using flexible connectors, non-flexible connectors, and / or combinations thereof. In embodiments including a continuous ring, the ring connectors (e.g., flexible, non-flexible, and / or a combination thereof) intersect the peaks of the ring, the valleys of the ring, the intermediate portions of the struts, and / or combinations thereof (e.g., peak to peak, valley to valley, intermediate to intermediate, peak to valley, peak to intermediate, valley to intermediate, valley to peak, intermediate to peak, intermediate to valley). The tube, sheet, or section may be ground and / or polished before or after cutting. Internal ridges may be formed, for example, to assist fluid flow. The parameters of the cut tube or sheet may be uniform or substantially uniform across one and / or more portions, or may vary within one and / or between multiple portions. For example, the proximal end portion 102 may have a first parameter, and the distal end portion 104 may have a second parameter different from the first parameter. In another example, the proximal portion 102 and the distal portion 104 may each have a first parameter, and the intermediate portion 106 may have a second parameter different from the first parameter. In yet another example, at least one of the proximal portion 102, the distal portion 104, and the intermediate portion 106 may have both a first parameter and a second parameter different from the first parameter.Cut tube parameters or sheet parameters may include, for example, radial strut thickness, circumferential strut width, strut shape, cell shape, cut pattern, cut type, material, density, porosity, tube diameter, and shape settings.

[0207] In some embodiments, perforation may result in a mesh having a relatively flexible middle section and a relatively rigid end section. Alternatively, the support structure may be an open-cell foam placed inside the tube.

[0208] The filaments, stent grafts, or parts thereof of a stent, and / or the struts, stent grafts, or parts thereof of a cut stent, may have a modified surface to support drugs such as thrombosis modifiers, fluid flow modifiers, or antibiotics. The filaments, stent grafts, or parts thereof of a stent, and / or the struts, stent grafts, or parts thereof of a cut stent, may be at least partially covered by a coating containing drugs such as thrombosis modifiers, fluid flow modifiers, or antibiotics, embedded in, for example, one polymer layer or a series of polymer layers, which may be the same as or different from the polymer tube 108.

[0209] The thickness (e.g., diameter) of a stent, stent graft, or filament of a portion thereof, and / or cut stent, stent graft, or strut of a portion thereof is approximately 0.0005 inches to 0.02 inches, approximately 0.0005 inches to 0.015 inches, approximately 0.0005 inches to 0.01 inches, approximately 0.0005 inches to 0.008 inches, approximately 0.0005 inches to 0.007 inches, approximately 0.0005 inches to 0.006 inches, approximately 0.0005 inches to 0.005 inches, and approximately 0.0005 inches to 0.004 inches. Chi, approximately 0.0005 inches to approximately 0.003 inches, approximately 0.0005 inches to approximately 0.002 inches, approximately 0.0005 inches to approximately 0.001 inches, approximately 0.001 inches to approximately 0.02 inches, approximately 0.001 inches to approximately 0.015 inches, approximately 0.001 inches to approximately 0.01 inches, approximately 0.001 inches to approximately 0.008 inches, approximately 0.001 inches to approximately 0.007 inches, approximately 0.001 inches to approximately 0.006 inches, approximately 0.001 inches to approximately 0.005 inches, approximately 0.001 inches to approximately 0.004 inches, approximately 0.001 inches to approximately 0.003 inches, approximately 0.001 inches inches to approximately 0.002 inches, approximately 0.002 inches to approximately 0.02 inches, approximately 0.002 inches to approximately 0.015 inches, approximately 0.002 inches to approximately 0.01 inches, approximately 0.002 inches to approximately 0.008 inches, approximately 0.002 inches to approximately 0.007 inches, approximately 0.002 inches to approximately 0.006 inches, approximately 0.002 inches to approximately 0.005 inches, approximately 0.002 inches to approximately 0.004 inches, approximately 0.002 inches to approximately 0.003 inches, approximately 0.003 inches to approximately 0.02 inches, approximately 0.003 inches to approximately 0.015 inches, approximately 0.003 inches to approximately 0.01 inches, approximately 0.003 inches to approximately 0.008 inches, approximately 0.003 inches to approximately 0.007 inches, approximately 0.003 inches to approximately 0.006 inches, approximately 0.003 inches to approximately 0.005 inches, approximately 0.003 inches to approximately 0.004 inches, approximately 0.004 inches to approximately 0.02 inches, approximately 0.004 inches to approximately 0.015 inches, approximately 0.004 inches to approximately 0.01 inches, approximately 0.004 inches to approximately 0.008 inches, approximately 0.004 inches to approximately 0.007 inches, approximately 0.004 inches to approximately 0.006 inches, approximately 0.004 inches to approximately 0.005 inches, approximately 0.005 inches to approximately 0.0.02 inches, approximately 0.005 inches to approximately 0.015 inches, approximately 0.005 inches to approximately 0.01 inches, approximately 0.005 inches to approximately 0.008 inches, approximately 0.005 inches to approximately 0.007 inches, approximately 0.005 inches to approximately 0.006 inches, approximately 0.006 inches to approximately 0.02 inches, approximately 0.006 inches to approximately 0.015 inches, approximately 0.006 inches to approximately 0.01 inches, approximately 0.006 inches to approximately 0.008 inches, approximately 0.006 inches to approximately 0.007 inches The thickness may be approximately 0.007 inches to 0.02 inches, 0.007 inches to 0.015 inches, 0.007 inches to 0.01 inches, 0.007 inches to 0.008 inches, 0.008 inches to 0.02 inches, 0.008 inches to 0.015 inches, 0.008 inches to 0.01 inches, 0.01 inches to 0.02 inches, 0.01 inches to 0.015 inches, or 0.015 inches to 0.02 inches. Other thicknesses are also possible, including thicknesses greater or less than the specified thickness. Filaments and / or struts containing certain materials (e.g., biodegradable materials, materials with low resilience, etc.) may be thicker than the specified thickness.

[0210] The thickness of the filaments and / or struts can be based on at least one of the following: the size of the device or device part (e.g., diameter and / or length), porosity, radial strength, material, amount of filaments and / or struts, cut pattern, weave pattern, layering pattern, etc. For example, larger devices or device parts used to treat large blood vessels such as coronary arteries may benefit from larger filament and / or strut thicknesses (e.g., greater than approximately 0.006 inches), medium-sized devices or device parts used to treat medium-sized blood vessels such as peripheral arteries may benefit from medium-sized filament and / or strut thicknesses (e.g., approximately 0.003 inches to approximately 0.006 inches), and small devices or device parts used to treat small blood vessels such as veins and neurovascular vessels may benefit from smaller filament and / or strut thicknesses (e.g., less than approximately 0.003 inches).

[0211] The inner or outer diameter of a stent, stent graft, or first end portion, second end portion, intermediate portion, or sub-portion of a stent can be approximately 1 mm to 12 mm, 1 mm to 10 mm, 1 mm to 8 mm, 1 mm to 6 mm, 1 mm to 4 mm, 1 mm to 2 mm, 2 mm to 12 mm, 2 mm to 10 mm, 2 mm to 8 mm, 2 mm to 6 mm, 2 mm to 4 mm, 4 mm to 12 mm, 4 mm to 10 mm, 4 mm to 8 mm, 4 mm to 6 mm, 6 mm to 12 mm, 6 mm to 10 mm, 6 mm to 8 mm, 8 mm to 12 mm, 8 mm to 10 mm, or 10 mm to 12 mm, taking into account the thickness of the filament or strut. Some such diameters may be suitable for treating coronary arteries, for example. The inner or outer diameter of a stent, stent graft, or portion of a stent can be approximately 1mm to 10mm, 1mm to 8mm, 1mm to 6mm, 1mm to 4mm, 1mm to 2mm, 2mm to 10mm, 2mm to 8mm, 2mm to 6mm, 2mm to 4mm, 4mm to 10mm, 4mm to 8mm, 4mm to 6mm, 6mm to 10mm, 6mm to 8mm, or 8mm to 10mm, taking into account the thickness of the filament or strut. Some such diameters may be suitable for treating veins, for example. The inner or outer diameter of a stent, stent graft, or portion of a stent can be approximately 6mm to 25mm, 6mm to 20mm, 6mm to 15mm, 6mm to 12mm, 6mm to 9mm, 9mm to 25mm, 9mm to 20mm, 9mm to 15mm, 9mm to 12mm, 12mm to 25mm, 12mm to 20mm, 12mm to 15mm, 15mm to 25mm, 15mm to 20mm, or 20mm to 25mm, taking into account the thickness of the filament or strut. Some such diameters may be suitable for treating peripheral blood vessels, for example.The inner or outer diameter of a stent, stent graft, or portion of a stent can be approximately 20mm to 50mm, 20mm to 40mm, 20mm to 35mm, 20mm to 30mm, 30mm to 50mm, 30mm to 40mm, 30mm to 35mm, 35mm to 50mm, 35mm to 40mm, or 40mm to 50mm, taking into account, for example, the thickness of the filament or strut. Some such diameters may be suitable for treating, for example, the aorta. Other diameters, including those larger or smaller than the specified diameters, may also be considered. The diameter of the device may indicate the diameter of a first end portion, a second end portion, or an intermediate portion, each of which may be in an expanded or unexpanded configuration. The diameter of the device may indicate the average diameter of the device when all parts of the device are in an expanded or unexpanded configuration.

[0212] The lengths of the stent, stent graft, or the first end portion, second end portion, intermediate portion, or sub-portion of the stent are approximately 5mm to 150mm, 5mm to 110mm, 5mm to 70mm, 5mm to 50mm, 5mm to 25mm, 5mm to 20mm, 5mm to 10mm, 10mm to 150mm, 10mm to 110mm, 10mm to 70mm, 10mm to 50mm, 10mm to 25mm, and 10mm to 2 It can be 0mm, approximately 20mm to 150mm, approximately 20mm to 110mm, approximately 20mm to 70mm, approximately 20mm to 50mm, approximately 20mm to 25mm, approximately 25mm to 150mm, approximately 25mm to 110mm, approximately 25mm to 70mm, approximately 25mm to 50mm, approximately 50mm to 150mm, approximately 50mm to 110mm, approximately 50mm to 70mm, approximately 70mm to 150mm, approximately 70mm to 110mm, or approximately 110mm to 150mm. Other lengths including lengths longer or shorter than the specified length are also possible.

[0213] The porosity of a stent, stent graft, or first end portion, second end portion, intermediate portion, or sub-portion of a stent can be approximately 5% to 95%, approximately 5% to 50%, approximately 5% to 25%, approximately 5% to 10%, approximately 10% to 50%, approximately 10% to 25%, approximately 25% to 50%, approximately 50% to 95%, approximately 50% to 75%, approximately 50% to 60%, approximately 60% to 95%, approximately 75% to 90%, approximately 60% to 75%, and combinations thereof. The density of the stent may be inversely proportional to the porosity of the stent. The porosity of a portion of the stent covered by a graft can be approximately 0%. The porosity can vary depending on the purpose of the different portions of the stent. For example, the intermediate portion may have a low porosity to increase the fluid flow through the device, while the end portion may have an even lower porosity to increase flexibility and wall juxtaposition.

[0214] Figure 25A is a schematic side elevation view of yet another exemplary embodiment of the prosthesis 500. The prosthesis, stent, or device 500 comprises and / or essentially consists of a plurality of filaments 502 woven together in a woven structure. The stent 500 may be without graft material, as will be described in more detail below.

[0215] The filament 502, which may also be described as a wire, ribbon, strand, etc., can be constructed in a woven, braided, layered, or otherwise intersecting manner. The filament 502 is generally elongated and has a cross-section such as circular, elliptical, square, or rectangular. An exemplary nonwoven filament may have a first filament layer wound in a first direction and a second filament layer wound in a second direction, and at least a portion of the filament ends are joined together (for example, by joining them to an expandable ring). Exemplary woven patterns include one above and one below one (for example, shown in Figure 25A), two above and two below one, two above and two below two, and / or combinations thereof, but other woven patterns are also possible. At the intersections of the filaments 502, the filaments 502 can be wound spirally, intersect in a sliding relationship, and / or combinations thereof. The filaments 502 may be loose (for example, joined together by weaving), and / or may include joining elements such as welds, sleeves, and / or combinations thereof. The ends of the filament 502 can be curved and crimped to a ring (for example, by crimping the ends with a radiopaque material such as titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, etc., which can also act as a radiopaque marker), twisted, ball-welded, joined, or a combination thereof. The woven edge may include the ends of the filament 502 and / or the curved filament 502, and may have open cells, fixed or unfixed filaments 502, welds, adhesives or other melting means, radiopaque markers, or a combination thereof.

[0216] The stent 500 has open, uncovered areas between pores 504 or filaments 502. The porosity of the stent 500 can be calculated by dividing the outer surface area of ​​the pores 504 by the total outer surface area of ​​the stent 500. The porosity may be affected by parameters such as the number of filaments 502, the braiding angle 506, the size of the filaments 502 (e.g., diameter), and combinations thereof.

[0217] The porosity of Stent 500 is approximately less than 50% (e.g., the covering area is slightly larger than the open area), approximately 0% (e.g., there is almost no open area) to approximately 50%, approximately 0% to approximately 45%, approximately 0% to approximately 40%, approximately 0% to approximately 35%, approximately 0% to approximately 30%, approximately 0% to approximately 25%, approximately 0% to approximately 20%, approximately 0% to approximately 15%, approximately 0% to approximately 10%, and approximately 0%. ~5%, 5%~50%, 5%~45%, 5%~40%, 5%~35%, 5%~30%, 5%~25%, 5%~20%, 5%~15%, 5%~10%, 10%~50%, 10%~45%, 10%~40%, 10%~35%, 10%~30%, 10%~25% Approximately 10% to 20%, approximately 10% to 15%, approximately 15% to 50%, approximately 15% to 45%, approximately 15% to 40%, approximately 15% to 35%, approximately 15% to 25%, approximately 15% to 20%, approximately 20% to 50%, approximately 20% to 45%, approximately 20% to 40%, approximately 20% to 35%, approximately 20% to 25%, approximately 25% to 50%, approximately 25 Percentages can be approximately 45%, 25% to 40%, 25% to 35%, 30% to 50%, 30% to 45%, 30% to 40%, 30% to 35%, 35% to 50%, 35% to 45%, 35% to 40%, 40% to 50%, 40% to 45%, 45% to 50%, and combinations thereof.

[0218] In some embodiments where the porosity is less than approximately 50%, it is possible to prevent blood from perfusing through the sidewalls of the stent 500 under normal vascular pressure (e.g., pressure loss across the vessel, pressure loss from the afferent to the efferent duct). In certain such embodiments, blood flowing into the proximal end of the stent 500 can be directed toward the distal end of the stent 500 to pass through the lumen of the stent 500 without the use of graft material (e.g., substantially without graft material), but still without causing blood loss through the sidewalls of the stent 500 or substantial blood loss. In contrast, in certain so-called "flow diverting stents," the porosity is specifically designed to be greater than approximately 50% to ensure perfusion into the efferent duct.

[0219] The density of stent 500 can be inversely proportional to the porosity (for example, the outer surface area of ​​filament 502 divided by the total outer surface area of ​​stent 500). The density of stent 500 can be obtained by subtracting the porosity value shown above from 100%.

[0220] The filament 502 is at a certain braiding angle 506 with respect to an axis perpendicular to the longitudinal axis of the stent 500 (for example, shown by an illustrative dashed line in Figure 25A). The braiding angle 506 can be in the range of just over 90 degrees and just under 180 degrees. The braiding angle 506 can be acute or obtuse. In some embodiments, the braiding angle 506 is about 90 to about 180 degrees, about 120 to about 180 degrees, about 150 to about 180 degrees, about 160 to about 180 degrees, about 170 to about 180 degrees, about 160 to about 170 degrees, about 165 to about 175 degrees, and combinations thereof. In some embodiments, the closer the braiding angle 506 is to 180 degrees, the greater the radial strength of the stent 500. Device 500 with greater radial strength can help open or maintain open fistulas (formed, for example, as described herein). Other factors such as the diameter of the filaments 502, the material of the filaments 502, and the number of filaments 502 can also affect radial strength.

[0221] All filaments 502 may be the same, or some filaments 502 may have different parameters (e.g., material, dimensions, combinations thereof). In some embodiments, some filaments 502 include a shape memory material (e.g., nitinol), and other filaments 502 include another material (e.g., aramid fiber (e.g., Kevlar®), Dacron®, biocompatible polymer, etc.). The shape memory material can provide a mechanical structure, while the other material can provide low porosity (e.g., by thicker sidewall dimensions).

[0222] Figure 25B is a schematic side elevation view of yet another exemplary embodiment of the prosthesis 520. The prosthesis or stent or device 520 includes and / or consists essentially of these filaments, a first plurality of filaments 522 woven together in a first woven structure, and a second plurality of filaments 524 woven together in a second woven structure. The stent 520 may be without graft material, as will be described in further detail herein. The first plurality of filaments 522 may be similar to the filaments 502 of the stent 500 described with respect to Figure 25A. In some embodiments, the filaments 522 may not have sufficient radial force to keep the fistula open and / or to juxtapose the side walls of the artery and / or vein. In certain such embodiments, the filaments 524 may function as an auxiliary support structure that provides radial force. Filament 524 may be located radially outside filament 522 (e.g., as shown in Figure 25B), radially inside filament 522, and / or integrated with filament 522 (e.g., so that the first and second woven structures are not easily separable). Filament 524 may be made of the same or different material as filament 522, the same or different thickness as filament 522, and / or filament 524 may be braided with the same or different parameters (e.g., braiding angle) as filament 522 so that filament 524 obtains a greater radial force. Filament 524 may be bonded to filament 522 (e.g., to form a single deployable stent 520) or deployed separately. For example, if filament 522 is deployed after filament 524 has been deployed, filament 524 can be kept open, and filament 522 can be expanded substantially without reaction force within the lumen formed by filament 524. In another example, if filament 524 is unfolded after filament 522 has been unfolded, filament 524 can act as an expanding force on the portion of filament 522 where an expanding force is required.

[0223] Although Figure 25B shows a second woven structure, auxiliary support structures may be provided additionally or alternatively, such as helical coils, cut hypotubes, or combinations thereof. The determination of the porosity of the prosthesis 520 can be based primarily on the porosity of the first woven structure, so that the auxiliary support structures can be designed to primarily provide radial forces (e.g., forces sufficient to open or keep a fistula open).

[0224] Although shown as uniform or substantially uniform over the length of the stent 500, the parameters of the stent 500 and filament 502 may vary over the stent 500, as described, for example, with respect to Figure 25C. Uniformity may have advantages such as reduced manufacturing costs, reduced need for precise placement, and / or other benefits. Non-uniformity may allow for specialization or customization for specific properties and / or functions along varying lengths, and / or other benefits.

[0225] Figure 25C is a schematic side elevation view of yet another exemplary embodiment of the prosthesis 540. The prosthesis, stent, or device 540 comprises and / or essentially consists of a plurality of filaments 542 woven together in a braided structure. The stent 540 may be without graft material, as will be described in further detail herein. The stent 540 has a first longitudinal section or segment or portion 544 and a second longitudinal section or segment or portion 546. Parameters such as porosity (e.g., shown in Figure 25B), braiding angle, braiding type, parameters of the filaments 542 (e.g., diameter, material, etc.), presence of an auxiliary support structure (e.g., an auxiliary support structure), stent diameter, stent shape (e.g., cylindrical, frustoconical), and combinations thereof may differ between the first longitudinal section 544 and the second longitudinal section 546. The porosity may vary depending on the purpose of a particular part of the stent 540. For example, the first longitudinal section 544 can be configured to be placed in an artery and a fistula, and can have a low porosity (e.g., less than 50%, as described with respect to stent 500 in Figure 25A), which can increase the fluid flow through the stent 500. On the other hand, the second longitudinal section can be configured to be placed in a vein, and can have a higher porosity, which can improve flexibility and wall juxtaposition.

[0226] In some embodiments, the stent comprises: a first longitudinal section comprising and / or essentially consisting of a low-porosity woven fabric configured to divert flow from artery to fistula, and without auxiliary support structures; a second longitudinal section comprising and / or essentially consisting of a low-porosity woven fabric configured to divert blood flow through fistula, and with auxiliary support structures configured to keep the fistula open; and a third longitudinal section comprising and / or essentially consisting of a low-porosity woven fabric configured to divert flow from fistula to vein. In certain such embodiments, the first longitudinal section may be configured as stent 500 in Figure 25A, and the third longitudinal section may be configured as stent 500 in Figure 25A or as stent 540 in Figure 25C.

[0227] The difference between the first longitudinal section 544 and the second longitudinal section 546 can be given during manufacturing (e.g., by braiding parameters, shape settings, etc.) and / or in situ (e.g., during and / or after unfolding (e.g., by stent packing)).

[0228] For example, other differences between the first longitudinal section 544 and the second longitudinal section 546 described herein (including, for example, laser-cut sections, further longitudinal sections, etc.) are also conceivable. In some embodiments, the stent has a first longitudinal section comprising and / or essentially consisting of a low-porosity woven fabric configured to divert flow from artery to fistula; a second longitudinal section comprising and / or essentially consisting of a low-porosity laser-cut section positioned in the fistula and configured to divert blood through the fistula and / or keep the fistula open; and a third longitudinal section comprising and / or essentially consisting of a low-porosity woven fabric configured to divert flow from the fistula to vein. In a particular embodiment, the first longitudinal section may be configured as stent 500 in Figure 25A, and the third longitudinal section may be configured as stent 500 in Figure 25A or as stent 540 in Figure 25C.

[0229] Figure 27 schematically shows an exemplary embodiment of the prosthesis 720. The anatomical structure of the prosthesis 720 in Figure 27 will be described in more detail below. The prosthesis 720 has a first longitudinal section 722, a second longitudinal section 724, and a third longitudinal section 726 between the first longitudinal section 722 and the second longitudinal section 724. The porosity of the prosthesis 720 can be such that, even if substantially lacking graft material, a low-porosity woven structure allows fluid to flow substantially through the lumen of the prosthesis 720 without substantially perfusing through the side walls.

[0230] In embodiments in which the prosthesis 720 is used in the peripheral vascular system, the first longitudinal section 722 can be described as an arterial section, the second longitudinal section 724 can be described as a venous section, and the third longitudinal section 726 can be described as a transition section. The first longitudinal section 722 is configured to juxtapose the sidewall of an artery 700 or another lumen. For example, in the case of several peripheral arteries, the first longitudinal section 722 may have an expanded diameter of about 2 mm to about 4 mm (e.g., about 3 mm). The second longitudinal section 724 is configured to juxtapose the sidewall of a vein 702 or another lumen. For example, in the case of several peripheral veins, the second longitudinal section 724 may have an expanded diameter of about 5 mm to about 7 mm (e.g., about 6 mm). In some embodiments, the second longitudinal section 724 and the third longitudinal section 726 may have a shape that includes a frustoconical shape tapering from a smaller diameter to a larger diameter than the first longitudinal section 722, rather than being substantially cylindrical as shown in Figure 27.

[0231] The length of the prosthesis 720 can be such that it is positioned within the artery 700 and / or vein 702 (for example, sufficiently to prevent or block or restrict movement or displacement of the prosthesis 720 in the longitudinal direction) and spans the interstitial tissue T between the artery 700 and the vein 702. For example, in the case of some peripheral arteries, the length of the first longitudinal section 722 in the dilated or expanded state can be about 20 mm to about 40 mm (e.g., about 30 mm). In another example, in the case of some peripheral veins, the length of the second longitudinal section 724 in the dilated or expanded state can be about 10 mm to about 30 mm (e.g., about 20 mm). In yet another example, in the case of some peripheral vascular systems, the length of the third longitudinal section 726 in the dilated or expanded state can be about 5 mm to about 15 mm (e.g., about 10 mm). The total length of the prosthesis 720 in the expanded or unfolded state can be approximately 30 mm to 100 mm, or approximately 45 mm to 75 mm (e.g., approximately 60 mm). The thickness of the interstitial tissue T is shown as approximately 2 mm, but other dimensions may be possible depending on the specific anatomical structure of the unfolded location. For example, other dimensions of the prosthesis 720, the first longitudinal section 722 and / or the second longitudinal section 724 described herein may also be possible.

[0232] The third longitudinal section 726 has a frustoconical or tapered shape that expands from a smaller diameter of the first longitudinal section 722 to the second longitudinal section 724. The transition points between the longitudinal sections 722, 724, and 726 may be clearly distinguishable or not. For example, a transition section may be said to include a portion of the first longitudinal section 722 and the third longitudinal section 726, or the third longitudinal section 726 may be said to include a cylindrical portion having the same diameter as the first longitudinal section 722. The longitudinal sections 722, 724, and 726 may differ from the shapes and dimensions described above and / or in other respects (e.g., material, pattern, etc.). For example, one or more portions may be cylindrical, frustoconical, etc., as shown in Figures 12, 13, and 27 and described herein.

[0233] The first longitudinal section 722 and / or the third longitudinal section 726 may have a relatively high radial force, for example, a force configured to keep the fistula open, while the second longitudinal section 724 may have a relatively low radial force. In some embodiments, the first longitudinal section 722 and / or the third longitudinal section 726 may comprise a balloon-expandable stent, a woven stent with a high braiding angle, etc. In some embodiments, the second longitudinal section 724 may comprise a self-expanding stent, a woven stent with a low braiding angle, etc. Combinations of laser-cut stents, woven stents, different cut patterns, different braiding patterns, etc., are described in further detail herein. In some embodiments, the longitudinal sections 722, 724, and 726 may be integrated or separate. The second longitudinal section 724 can be relatively flexible, for example, while having relatively low radial forces, thereby helping the second longitudinal section 724 flex along with the anatomical structure during blood flow pulses.

[0234] In some embodiments, the second longitudinal section 724 and / or the third longitudinal section 726 may comprise several graft materials (including, for example, silicone). The graft material can block or prevent flow through the side walls of the prosthesis 720 and / or can be used to carry a drug. For example, depending on the purpose of the graft material, the graft material may or may not block the pores of the portion of the prosthesis 720.

[0235] The proximal and / or distal ends of the 720 prosthesis can be made non-traumatic by, for example, end treatment, a low braiding angle, a small filament diameter, or a combination thereof.

[0236] The radial strength or compressive resistance of a stent, stent graft, or first end portion, second end portion, intermediate portion, or sub-portion of a stent can be approximately 0.1 N / mm to approximately 0.5 N / mm, approximately 0.2 N / mm to approximately 0.5 N / mm, approximately 0.3 N / mm to approximately 0.5 N / mm, approximately 0.1 N / mm to approximately 0.3 N / mm, approximately 0.1 N / mm to approximately 0.2 N / mm, approximately 0.2 N / mm to approximately 0.5 N / mm, approximately 0.2 N / mm to approximately 0.3 N / mm, or approximately 0.3 N / mm to approximately 0.5 N / mm.

[0237] The values ​​of several parameters of a stent, stent graft, or first end portion, second end portion, intermediate portion, or sub-portion of a stent can be related to each other (e.g., proportional). For example, the ratio of the thickness of the strut or filament to the diameter of the device portion having the strut or filament can be about 1:10 to about 1:250, about 1:25 to about 1:175, or about 1:50 to about 1:100. In another example, the ratio of the length of the device or device portion to the diameter of the device or device portion may be about 1:1 to about 50:1, about 5:1 to about 25:1, or about 10:1 to about 20:1.

[0238] Parts of the device may include radiopaque materials. For example, the filaments and / or struts of a stent, stent graft, or first end portion, second end portion, intermediate portion, or sub-part of a stent may include (for example, be made at least partially from) titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, and combinations thereof. In another example, the filaments and / or struts of a stent, stent graft, or part of a stent may include (for example, be made at least partially from) a material having a density greater than about 9 grams per cubic centimeter. Separate radiopaque markers may be attached to some parts of the device. For example, radiopaque markers may be attached to the proximal end of the device or part of the device (e.g., the proximal part of the intermediate portion, the proximal part of the distal portion), the distal end of the device or part of the device (e.g., the distal part of the intermediate portion, the distal part of the proximal portion), and / or other parts. Radiopaque markers between the ends of a device can be useful for distinguishing transitions, such as between materials or between parts. Radiopaqueness can vary over the length of the device. For example, the proximal portion may have a first radiopaqueness (e.g., due to the distal portion material and / or a separate marker), and the distal portion may have a second radiopaqueness different from the first (e.g., due to the distal portion material and / or a separate marker). Inflatable members, such as balloons, can be filled with radiopaque fluid. Inflatable members, such as balloons, may include radiopaque markers bonded to and / or integrated with them (e.g., on the outer surface of the inflatable member).

[0239] In some embodiments, the device has polymer tubes and no support structure is provided. The intermediate portion of such a device can be made relatively more flexible than the end portion, for example, by reducing the wall thickness of the polymer tubes within the intermediate portion.

[0240] When a mesh or other support structure is provided in combination with the polymer tube, the support structure can be positioned around the outside of the tube, within the lumen of the tube, or embedded within the wall of the tube. Two or more support structures may be provided, in which case each support structure may be positioned differently relative to the tube.

[0241] One or both of the end portions of the device may have implantable elements such as hooks, projections, or barbs configured to capture or grasp the inner wall of a blood vessel. The radial force of the expanded end portion may be sufficient to capture or grasp the inner wall of a blood vessel without the use of implantable elements.

[0242] There does not need to be a well-defined transition between the intermediate and end portions. For example, the mesh type, material, thickness, flexibility, etc., may change gradually from the end portion to the intermediate portion, or from the intermediate portion to the end portion.

[0243] The flexibility of the device may gradually increase as it moves from the end portion to the middle portion, as described, for example, with respect to devices 134 and 140. Changes in flexibility may be due to changes in mesh density (e.g., winding density, window size), pipe thickness, or other factors. The flexibility of the device may be uniform or substantially uniform over the entire length of the support structure (e.g., stent) or over several portions of the support structure (e.g., over the entire end portion, over the entire middle portion, over one end portion and the middle portion, but not over the other end portion, etc.).

[0244] The devices described herein are particularly suitable for use as transvascular shunts in percutaneous surgery and can be used for many other medical applications. For example, the devices can be used for the treatment of occluded vessels having tortuous or bent pathways, or in angioplasty where the vessel may bend or deform at or near the stent site. Stents can also be used, for example, in aortic grafting or after perforation during percutaneous procedures to repair damaged vessels. In some such cases, the middle portion of the device can allow the device to conform to the shape of the vessel and deform in accordance with the movement of the vessel, while the end portion remains fixed or in place, reducing the risk of fatigue failure. In another example, the device can be used to form a shunt between a healthy artery and a healthy vein for dialysis access and / or access for drug administration (e.g., intermittent injections for cancer treatment that may damage the vessel).

[0245] Referring again to Figures 4 and 7, the block material 251 can be used to help block or prevent backflow of arterial blood. As will be described in more detail here, additional methods and systems or other methods and systems can be used to block or prevent backflow of arterial blood, that is, in other words, to block or prevent the flow of arterial blood flowing into the veins from flowing in the normal pre-treatment direction of the blood flow within the veins, thereby bypassing oxygenated blood downstream to tissues such as the feet.

[0246] If left untreated, peripheral vascular disease (PVD) can progress to critical limb ischemia (CLI), characterized by severe chronic pain and extensive tissue loss. This tissue loss limits options for vascular regeneration and often leads to amputation. CLI is estimated to occur at a rate of approximately 50 to 100 cases per 100,000 cases per year and is associated with a 20% mortality rate within six months of onset.

[0247] Interventional radiologists have actively attempted to treat chronic lymphoma (CLI) by attempting to completely open chronic total occlusion (CTO), or by bypassing the CTO into the subarticular space using products such as the Medtronic Pioneer catheter, which attempts to pass a wire through the subarticular space adjacent to the CTO and then re-enter the vessel distal to the occlusion. Once the wire is in place, the user can optionally place a stent to create a wider channel and then provide a bypass conduit through the occlusion. Conventional approaches such as percutaneous transluminal angioplasty (PTA), stenting, and drug-eluting balloons (DEB) for treating PAD can be used additionally or alternatively to treat CLI when the wire can traverse the occlusion.

[0248] According to the amputee-calition.org website, some statistics regarding CLT issues are as follows: Nearly 2 million people in the United States have lost limbs. The main causes of limb loss are as follows: Vascular diseases (54%) (diabetes and peripheral artery disease (PAD)), Trauma (45%), and, Cancer (less than 2%). Approximately 185,000 mutilations are performed in the United States every year. In 2007, the total cost of hospitalization associated with limb amputations exceeded $6.5 billion. Survival rates after amputation vary depending on a variety of factors. For those who undergo amputation due to vascular disease (including PAD and diabetes), the 30-day mortality rate is reported to be 9% to 15%, while long-term survival rates are 60% at 1 year, 42% at 3 years, and 35% to 45% at 5 years. Nearly half of those who lose a limb due to dysvascular disease die within five years. This is higher than the five-year mortality rate for those with colorectal cancer, breast cancer, and prostate cancer. Among people with diabetes who have undergone lower limb amputation, up to 55% will require the amputation of another leg within two to three years.

[0249] CLI has been surgically treated since the early 1900s by arterializing the veins through limb ossification. A small number of clinical trials using limb ossification approaches, such as those outlined in the 2006 meta-analysis paper entitled "Meta-analysis of the clinical effectiveness of venous arterialization for salvage of critically ischemiclimbs" by Lu et al. (European Journal of Vascular and Endovascular Surgery, vol. 31, pp. 493-499), have been published over many years. The aforementioned paper reached the following results and conclusions: result: A total of 56 trials were selected for comprehensive review. No randomized controlled trials (RCTs) were identified. Seven patient groups, including 228 patients, met the selection criteria. The overall limb preservation rate at 1 year was 71% (95% CI: 64%–77%), and the 1-year secondary patency rate was 46% (95% CI: 39%–53%). The majority of patients who avoided major amputation had successful wound healing, no rest-time pain, and no serious complications. Conclusion: Based on limited evidence, venous arterialization can be considered a viable alternative to major amputation in patients with "inoperable" chronic severe limb ischemia.

[0250] Of the other diseases described herein, the methods and systems described herein can create a fistula between an artery and a vein (AV) in the subknee (BKT) vascular system using an intravascular, minimally invasive approach. Such methods may be suitable for patients who (i) have a clinical diagnosis of symptomatic severe limb ischemia as defined by Rutherford 5 or 6 (severe ischemic ulcer or obvious gangrene), (ii) have been evaluated by a vascular surgeon and interventionist and determined not to be able to undergo surgical or endovascular treatment, and / or (iii) have a clear efficacy against major amputation.

[0251] 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 launch catheter with a needle, etc.), a second ultrasound catheter (e.g., a venous catheter, a target catheter, etc.), and a prosthesis (e.g., a covered nitinol stent graft 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 the ultrasound catheter(s). The catheters and prostheses described above can be used in the system or kit, and details of other, additional, and / or modified, possible components are described below.

[0252] Figure 14A is a schematic side cross-sectional view of an exemplary embodiment of an ultrasonic emitting catheter 170 having a needle 172 (e.g., a first ultrasonic catheter, an arterial catheter (e.g., when the needle is extended from an artery into a vein), or a venous catheter (e.g., when the needle is extended from a vein into an artery)). The catheter 170 is positioned in an artery with the needle 172 retracted within the lumen of the catheter 170. The catheter 170 can be tracked along a guidewire (e.g., a 0.014-inch (approximately 0.36 mm) guidewire) and / or positioned through a sheath in an artery (e.g., a femoral artery) and advanced to a point of complete occlusion of the artery (in the tibial artery). The catheter 170 has a handle 174 with a pusher ring 176. By the longitudinal or distal advancement of the pusher ring 176, the needle 172 can be advanced out of the lumen of the catheter 170 into the vein. Other advancement mechanisms for the needle 172 are also conceivable (e.g., rotary, motorized, etc.). Before, after, and / or while the needle is being advanced, a guide wire (e.g., a 0.014-inch (approximately 0.36 mm) guide wire) can be placed through the needle 172 (as described, for example, with respect to guide wire 14 in Figure 3), and this guide wire may be called a cross wire.

[0253] Figure 14B is an expanded schematic side cross-sectional view of the distal portion of the ultrasonic emitting catheter 170 within circle 14B of Figure 14A. When the needle 172 advances or starts, it extends radially outward from the lumen 173 of the catheter 170. In some embodiments, the lumen 173 terminates close to the ultrasonic transmitter 178. The needle 172 can extend along a path that aligns with (e.g., parallel to) the path of the directional ultrasonic signal transmitted by the ultrasonic transmitter 178. Figure 14B also shows a lumen 175 which can be used to house a guidewire that tracks the catheter 170 to a desired position.

[0254] Figure 15A is a schematic side view of exemplary embodiments of the ultrasound-targeted catheter 180 (e.g., a second ultrasound catheter, an arterial catheter (e.g., when extending a needle from a vein into an artery), or a venous catheter (e.g., when extending a needle from an artery into a vein)). Figure 15B is an expanded schematic side cross-sectional view of the ultrasound-targeted catheter 180 within circle 15B of Figure 15A. Figure 15C is an expanded schematic side cross-sectional view of the ultrasound-targeted catheter 180 within circle 15C of Figure 15A. The catheter 180 can be tracked along a guidewire (e.g., a 0.014 inch (approximately 0.36 mm) guidewire) and / or positioned through a sheath in a vein (e.g., a femoral vein) and advanced to a point (e.g., in the tibial artery) and / or an occlusion in the artery that is close to and / or parallel to the distal end of the catheter 170. The catheter 180 has an ultrasonic receiving transducer 182 (e.g., an omnidirectional ultrasonic receiving transducer) that can act as a target in the vein to align the needle 172 of the catheter 170. The catheter 180 can be left in place or remain stationary or substantially stationary, while the catheter 170 rotates and moves longitudinally to obtain a good or optimal ultrasonic signal indicating that the needle 172 is aligned with the catheter 180.

[0255] Catheters 170, 180 may be connected to an ultrasonic transceiver that is connected to and controlled by computer-executed transceiver software. As described further herein, catheter 170 has a flat ultrasonic transmitter 178 or a directional ultrasonic transmitter 178 configured to transmit an ultrasonic signal having a small angle spread or a tight beam (e.g., a small beamwidth) in the direction of the path of the needle 172 as the catheter 170 advances from the lumen 173. Catheter 180 has an omnidirectional (360-degree) ultrasonic receiver 182 configured to act as a target for the ultrasonic signal transmitted by the directional transmitter 178 of catheter 170. As the needle 172 is extended (for example by advancing the ring 176 of the handle 174 longitudinally), the catheter 170 rotates until a peak ultrasound signal is displayed indicating that the needle 172 is aligned with the catheter 180 so that the needle 172 can exit the artery in which the catheter 170 is located, pass through the interstitial tissue, and enter the vein in which the catheter 180 is located.

[0256] Figure 16 shows an exemplary embodiment of a graph for detecting catheter alignment, which can be displayed on a display device of an ultrasound system (e.g., a laptop, tablet computer, smartphone, or a combination thereof). The graph in Figure 16 shows that a signal transmitted from an intravenous transmitting catheter is received by an intravenous receiving catheter. The second frequency envelope on the right is the received signal. The distance from the left side of the illustrated screen to the leading edge of the second frequency envelope may indicate the distance between the catheters. The operator can move the catheter in the artery in both the rotational and longitudinal directions until, for example, the second envelope is at its maximum (indicating that the catheter is accurately oriented).

[0257] Figure 17 is a schematic side elevation view of an exemplary embodiment of a prosthesis (e.g., stent, stent graft) delivery system 190. In some embodiments, the delivery system 190 is a 7Fr (approximately 2.3 mm) delivery system. Figure 18 is a schematic side elevation view of an exemplary embodiment of a prosthesis (e.g., stent, stent graft) 200. In Figure 17, the prosthesis (e.g., prosthesis 200, other prostheses described herein, etc.) is in a compressed or crimped state close to the distal end 192 of the delivery system 190. In some embodiments, the prosthesis 200 includes a shape-memory stent covered with, for example, a graft material as described herein. As the cross wire extends from the artery to the vein, the delivery system 190 can advance along the cross wire, for example, by advancing through the needle 172, as described herein. The prosthesis 200 can be deployed from the delivery system 190 by, for example, grasping the trigger handle 194 of the delivery system 190, thereby retracting the prosthesis 200 proximally and / or advancing it distally into the outer cover sheath. The prosthesis 200 can create a pathway through the interstitial tissue between the artery and the vein. Other types of delivery systems and prostheses are also conceivable.

[0258] Referring again to Figure 17, some non-limiting exemplary dimensions of the delivery system 190 are presented. The travel distance 196 of the trigger handle 194 can be, for example, about 0.4 inches (approximately 1 cm) to about 12 inches (approximately 30 cm), about 1 inch (approximately 2.5 cm) to about 8 inches (approximately 20 mm), or about 2 inches (approximately 5 cm) to about 6 inches (approximately 15 mm) (for example, about 2 inches (approximately 5 cm)). In some embodiments, the travel distance 196 of the trigger handle 194 is at least the same length as the length of the prosthesis 200 when deployed (for example, in a radially expanded state). In some embodiments, a transmission device or other mechanism may be used to shorten the travel distance 196 of the trigger handle 194 to less than the length of the prosthesis 200 when deployed (for example, in a radially expanded state). The distance 196 can be adjusted based on at least one of the following: the length of the deployed prosthesis 200, the degree to which the deployed prosthesis 200 is retracted, the deployment mechanism (for example, whether the outer sheath is retracted proximally, the prosthesis 200 is pushed distally forward, or both, whether the delivery system 190 includes a transmission mechanism, etc.), or a combination thereof. The length 197 of the outer sheath or catheter portion can be, for example, approximately 40 inches (approximately 1020 mm) to approximately 50 inches (approximately 1270 mm), approximately 46 inches (approximately 1170 mm) to approximately 47 inches (approximately 1190 mm), or approximately 46.48 inches (approximately 1180 mm) to approximately 46.7 inches (approximately 1186 mm). The total length 198 of the delivery system 190 from the proximal tip to the distal tip can be, for example, approximately 40 inches (approximately 1000 mm) to approximately 60 inches (approximately 1500 mm). Lengths 197 and 198 can be adjusted based on, for example, the length of the deployed prosthesis 200, the degree to which the deployed prosthesis 200 is retracted, the patient's height, the location of the occlusion being treated, or a combination thereof. In some embodiments, it is advantageous that the trigger handle 194 can be moved away from the vascular access point by, for example, about 10 cm to about 30 cm (e.g., at least about 20 cm), making it easier for the user to handle or manage.In some such embodiments, the length 197 may be about 120 cm to about 130 cm (e.g., in the case of an antegrade approach) or about 150 cm to about 180 cm (e.g., in the case of a contralateral approach).

[0259] Referring again to Figure 18, several non-limiting exemplary dimensions of the prosthesis 200 are presented, at least depending on the compressed state. The thickness 201 of the structural struts can be, for example, about 0.05 mm to about 0.5 mm or about 0.1 mm to about 0.2 mm (e.g., about 0.143 mm). The spacing 202 between the structural struts can be, for example, about 0.005 mm to about 0.05 mm or about 0.01 mm to about 0.03 mm (e.g., about 0.025 mm). The thickness 203 of the connecting struts can be, for example, about 0.05 mm to about 0.5 mm or about 0.1 mm to about 0.2 mm (e.g., about 0.133 mm). The longitudinal length 204 of the structural components can be, for example, about 1 mm to about 5 mm or about 2.5 mm to about 3 mm (e.g., about 2.8 mm). The longitudinal length 205 between structural components can be, for example, about 0.25 mm to about 1 mm or about 0.5 mm to about 0.6 mm (e.g., about 0.565 mm). The length 206 of the struts within the structural components, including all parts that wrap around front and back, can be, for example, about 25 mm to about 100 mm or about 65 mm to about 70 mm (e.g., about 67.62 mm). The total longitudinal length of the prosthesis 200 can be, for example, about 25 mm to about 150 mm or about 50 mm to about 70 mm (e.g., about 62 mm). A wide variety of laser-cut stents, woven stents and combinations thereof, including various dimensions, are also conceivable as described herein. The struts described herein may include portions that are not cut from wire or filament, or from hypo tubing or sheets.

[0260] The proximal and / or distal ends of the prosthesis 200 may optionally have a ring 210. The ring 210 can, for example, help to place the prosthesis 200 in an artery and / or vein. The circumferential width 211 of the ring 210 can be, for example, about 0.25 mm to about 1 mm or about 0.5 mm to about 0.75 mm (e.g., 0.63 mm). The longitudinal length 212 of the ring 210 can be, for example, about 0.25 mm to about 2 mm or about 0.5 mm to about 1 mm (e.g., 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 can be about 50:1 to about 100:1 (e.g., about 79:1). The dimensions 211 and 212 of the ring 210 can be adjusted based on at least one of the following: strut thickness, prosthesis diameter (e.g., relative to blood vessels), prosthesis length, material, shape setting characteristics, or combinations thereof.

[0261] Figure 19 is a schematic side elevation view of a prosthesis 220 of another exemplary embodiment. The prosthesis 200 can have the shape of the prosthesis 220 in a radially expanded state, for example, when unfolded from the delivery system 190. Figure 19 shows an exemplary shape of the prosthesis 220 having a first portion 221 and a second portion 225. The first portion 221 has a substantially cylindrical or tubular shape with a length 222 of about 15 mm to about 25 mm (e.g., about 21 mm) and a diameter 223 of about 2.5 mm to about 5 mm (e.g., about 3.5 mm). The second portion 225 has a substantially frustoconical or frustoconical shape with a length 226 of about 30 mm to about 50 mm (e.g., about 41 mm) and a widest diameter 227 such as about 4 mm to about 10 mm, about 4 mm to about 7 mm (e.g., about 5.5 mm). The taper angle of the second part 225 separating from the first part 221 can be about 0.02 to about 0.03 degrees (for example, about 0.024 degrees).

[0262] Further details relating to prostheses that can be used in accordance with the methods and systems described herein are contained in U.S. Patent Application No. 13 / 791185, filed on March 8, 2013, which in whole constitutes part of this specification by reference.

[0263] Figures 20A to 20H schematically illustrate exemplary embodiments of a method for performing retrograde perfusion. While this method is described in relation to the peripheral vascular system, such as the lower extremities, it can be adapted to other body cavities (e.g., the heart, other extremities, etc.) as needed. Several steps, such as anesthesia, incision of a specific site, and suturing, can be omitted as they are self-evident. In some embodiments, this method can be performed from a vein to an artery (e.g., by a venous catheter as described below).

[0264] Access to the femoral artery and femoral vein is obtained. For example, using the Seldinger technique, an introducer sheath (e.g., 7Fr (approximately 2.3 mm)) is inserted into the femoral artery, and an introducer sheath (e.g., 6Fr (approximately 2 mm)) is inserted into the femoral vein. A guidewire (e.g., 0.014 inches (approximately 0.36 mm), 0.035 inches (approximately 0.89 mm), 0.038 inches (approximately 0.97 mm)) is inserted through the introducer sheath in the femoral artery and guided into the distal portion of the posterior tibial artery or anterior tibial artery 300 in the affected area. A second guidewire (e.g., 0.014 inches (approximately 0.36 mm), 0.035 inches (approximately 0.89 mm), 0.038 inches (approximately 0.97 mm)) or snare is inserted through the introducer sheath in the femoral artery. In embodiments where a snare is used, the third guidewire, fourth guidewire, etc., described herein are accurate even if they are not numbered sequentially.

[0265] A venous access needle is inserted percutaneously into a target vein, such as the tibial vein (e.g., the proximal tibial vein (PTV)). In some embodiments, the venous access needle may be guided under ultrasound. In some embodiments, a contrast agent is injected retrogradely into the saphenous vein on the foot side and then flowed into the PTV. This pathway can be visualized using fluoroscopy so that the venous access needle can be guided by ultrasound alone or by ultrasound in addition to fluoroscopy.

[0266] The target vein can be accessed proximal and distally from below (e.g., a few inches or centimeters) where the launch catheter 310 is to be placed. In some embodiments, the target vein may be located within the ankle. Once the venous access needle is in the vein, a third guidewire (or a "second" guidewire if a snare is used instead of the second guidewire) is inserted into the venous access needle and advanced anterogradely within the target vein to the femoral vein. This access method is advantageous because it can reduce problems caused by advancing the wire retrogradely across venous valves, which will be described in detail below. The third guidewire is snareed, for example, using a fluoroscopy guide, and passed through the femoral vein sheath. The target catheter 320 is inserted into the femoral vein sheath through the snareed third guidewire. As shown in Figure 20A, the target catheter 320 is advanced along the third guidewire into the venous system until it approaches the guidewire and / or becomes parallel to the guidewire and / or approaches the occlusion 304 in the distal portion of the posterior tibial artery or anterior tibial artery in the affected area.

[0267] In some embodiments, the third guidewire may have an ultrasonic receiving transducer (e.g., omnidirectional) attached to provide a target for the signal transmitted by the firing catheter 310, or the target catheter 320 may be tracked along the third guidewire, either of which may eliminate the need for several techniques (e.g., accessing the femoral vein, introducing a venous introducer sheath, inserting the second guidewire, advancing the third guidewire antegrade to the femoral vein, snare the third guidewire, and advancing the target catheter 320 along the third guidewire).

[0268] In some embodiments, for example, ultrasound may be used to directly access the PTV, which may allow the target catheter 320 to be directly positioned in the PTV using, for example, a small sheath, thereby potentially eliminating the need for several techniques (e.g., femoral vein access, introduction of a venous introducer sheath, insertion of a second guidewire, and antegrade advancement of a third guidewire to the femoral vein).

[0269] In some embodiments, the catheter 320 is not an over-the-wire catheter but includes a guidewire and an ultrasound receiving transducer (e.g., omnidirectional). The catheter 320 can be inserted as a third guidewire, a second guidewire, or as a guidewire passing through a small sheath when directly accessing the PTV, as described above.

[0270] An ultrasonic transducer generally has two vibrating electrodes with ceramic surfaces spaced apart. The incoming or received ultrasonic signal waveforms are coupled to form a length-extended mode, as shown in Figure 21. Figure 21 is a schematic perspective view of an exemplary embodiment of an ultrasonic receiving transducer 350. The transducer can receive an ultrasonic signal if the proximal end, i.e., the upper end 352, and the distal end, i.e., the lower end 354, of the transducer are conductive and electrically connected to a wire. In some embodiments, the transducer 350 has a length 356 of about 0.1 mm to about 0.4 mm (e.g., about 0.25 mm). In some embodiments, the transducer 350 has an overlapping length 358 of about 0.1 mm to about 0.3 mm (e.g., about 0.2 mm). In some embodiments, the transducer 350 has a diameter that is similar to, substantially similar to, or the same as, the guidewire to which the transducer 350 is attached. In some embodiments, the signal receiving capability of the transducer 350 may be enhanced by an array or a series of laminated plates.

[0271] In some embodiments, the guidewire having an ultrasonic receiving transducer may have a piezoelectric film (including, for example, plastic) which can enhance the signal receiving capability of the transducer. Figure 22 is a schematic cross-sectional view of another exemplary embodiment of the ultrasonic receiving transducer 360. The ultrasonic receiving transducer 360 shown in Figure 22 has an optional lumen 368. The ultrasonic receiving transducer 360 has 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. Layer 366 may have a thickness of about 25 micrometers (μm, i.e., microns) to about 250 μm (e.g., at least about 50 μm).

[0272] The launch catheter 310 tracks along the guidewire in the proximal femoral and tibial arteries of the occlusion 304, close to the occlusion 304, as shown in Figure 20B. The catheter 310 may be located more proximal to the occlusion 304, depending on the fit of that portion of the anatomical structure of the retrograde perfusion process. In some embodiments, the catheter 310 may be positioned in the distal portion of the posterior or anterior tibial artery, for example, close to the catheter 320. In some embodiments, the catheter 310 may be positioned within a few inches or centimeters of the ankle.

[0273] The launch catheter 310 transmits a directional ultrasound signal. As indicated by arrows 311 and 312 in Figure 20C, the launch catheter 310 rotates and moves longitudinally until the signal is received by the target catheter 320. Once the signal is received, alignment is indicated, thereby successfully accessing the vein by extending a needle from the launch catheter 310, and as shown in Figure 20D, the crossed needle 314 advances from the catheter 310 and enters the tibial vein 302 from the tibial artery 300. The precision of positioning the crossed needle 314 to form a fistula between the artery 300 and the vein 302 can be confirmed, for example, using contrast agents and fluoroscopy.

[0274] In some embodiments, the ultrasound signal can be used to determine the distance between artery 300 and vein 302. Referring again to Figure 16, the distance from the left side of the illustrated screen to the leading edge of the second frequency envelope can be used as an indicator of the distance between catheters.

[0275] Referring again to Figure 16, the display device may graphically show the signal matching peaks to allow the user to determine the matching position. In some embodiments, the color may change, for example, from red to green, when the signal matching exceeds or falls below a threshold. In some embodiments, for example, when the matching signal exceeds a threshold, an audible signal may be transmitted, which may allow the user to continue looking at the patient rather than monitoring the screen substantially continuously.

[0276] In some embodiments, a horizontal line on the screen can be moved to indicate the maximum signal, or peak, achieved up to that point during the procedure. This line may be called the “peak hold.” If a higher signal value is achieved, the horizontal line moves to match that higher value. If the operation cannot raise the peak beyond the horizontal line, it may indicate maximum alignment. If the signal peak falls below the horizontal line by a certain amount, the catheter has moved and can no longer be properly positioned. Since the level of alignment indicated by the horizontal line is achieved beforehand during the procedure, the user will know that such a level of alignment can be achieved by further rotation and / or longitudinal operation.

[0277] A fourth guidewire 316 (e.g., 0.014 inches (approximately 0.36 mm)) (or a “third” guidewire if a snare is used instead of the second guidewire) is placed in the tibial vein 302 in the retrograde direction (of vein 302) toward the foot, as shown in Figure 20E, by passing it through the lumen of the crossing needle 314 of catheter 310. Lateral cuff pressure can be applied from above the needle intersection to reduce flow in artery 300, thereby preventing or inhibiting hematoma formation and / or filling the vein to facilitate valve crossing. With guidewire 316 remaining in place, catheters 310, 320 can be moved, extending from the introducer sheath in the femoral artery and entering the tibial vein 302 through the arterial tree.

[0278] In addition to or instead of the directional ultrasound techniques described herein, several techniques may be used to cross the guidewire 316 from artery 300 to vein 302.

[0279] In some embodiments, a tourniquet can be applied to the leg, thereby increasing the vein diameter. In some embodiments, a blocking material (e.g., a block balloon, as described with respect to Figures 4 and 7) may be used to increase the vein diameter. For example, the vein can be dilated by obstructing venous flow. A larger vein diameter allows for a larger target for the crossed needle 314, making the vein 300 easier to access by the crossed needle 314.

[0280] In some embodiments, the PTA balloon can be used in a target vein, and a needle catheter (e.g., Outback, available from Cordis) can target the PTA balloon under fluoroscopy. The crossed needle 314 can puncture the PTA balloon, and the pressure drop in the PTA balloon can confirm the proper positioning of the crossed needle 314. The PTA balloon can increase the vein diameter, thereby making the target area for the crossed needle 314 larger and facilitating access to the vein 300 by the crossed needle 314. The guidewire 316 can be advanced through the crossed needle 314 to the PTA balloon.

[0281] In some embodiments, a PTA balloon has a mesh (e.g., woven mesh) embedded within the balloon's polymer. If a balloon without such a mesh is punctured, the balloon material may rupture, potentially causing an embolism (e.g., balloon fragments being carried downstream). The mesh can help prevent tearing of the balloon material, thereby preventing or inhibiting the balloon material from causing an embolism.

[0282] In some embodiments, two PTA balloons spaced longitudinally along the catheter axis can be used in a target vein, and the needle catheter can target one of the PTA balloons. When one of the PTA balloons is punctured by the crossed needle 314, the punctured PTA balloon no longer acts as a barrier for the contrast agent, and the contrast agent in the well between the balloons can be released. The release of the contrast agent can be monitored using fluoroscopy. The PTA balloons can be on the same catheter side or on different catheter sides.

[0283] In some embodiments, two PTA balloons spaced longitudinally along the catheter axis can be used in a target vein, and the needle catheter can target the space or well between the PTA balloons. When the well is punctured by the crossed needle 314, the contrast agent in the well may be disturbed. The disturbance of the contrast agent can be monitored using fluoroscopy. The PTA balloons can be on the same catheter side or on different catheter sides.

[0284] In some embodiments where a PTA balloon may be used in combination with an ultrasound target within a target vein, the PA balloon catheter comprises a PTA balloon and an ultrasound receiving transducer (e.g., omnidirectional). In some such embodiments, the launch catheter 310 can target the PTA balloon and / or the ultrasound receiving transducer under fluoroscopy, as described herein. The crossed needle 314 can puncture the PTA balloon, and the pressure drop in the PTA balloon can confirm the proper positioning of the crossed needle 314. The PTA balloon can increase the vein diameter, making the target for the crossed needle 314 larger and facilitating access to the vein 300 by the crossed needle 314. The guidewire 316 can advance through the crossed needle 314 to the PTA balloon.

[0285] In some embodiments, a LeMaitre device (e.g., the UnBalloon® Non-Occlusive Modeling Catheter, available from LeMaitre Vascular, Burlington, Massachusetts) can be used within a target vein. In some embodiments, the LeMaitre device can increase the vein diameter. A larger vein diameter allows for a larger target for the crossed needle 314, making the vein 300 more easily accessible by the crossed needle 314. In some embodiments, the needle 314 can penetrate the LeMaitre device. In some such embodiments, the LeMaitre device can serve as a mesh target for the crossed needle 314 (e.g., including a radiopaque material visible under fluoroscopy). The mesh of the LeMaitre device can be expanded radially by advancing the proximal portion of the mesh distally and / or retracting the distal portion of the mesh proximal (e.g., by pushing both ends together like an umbrella), and / or by allowing the mesh to self-expand (e.g., in embodiments where at least a portion of the mesh is made of shape memory material). In some embodiments, the LeMaitre device can grasp the cross wire to hold it within the target vein when closing.

[0286] In some embodiments, the launch catheter 310 may be equipped with a first magnet having a first polarity, and the target catheter 320 may be equipped with a second magnet having a second polarity. When the magnets are close enough to exert a magnetic force that moves one or both of the catheters 310, 320, the cross catheter 314 can be advanced to create a fistula between the artery 300 and the vein 302. In some embodiments, the first magnet may be circumferentially aligned with the cross needle 314, and / or the launch catheter 310 may be magnetically shielded to allow rotational alignment. In some embodiments, the second magnet may be relatively thin in the longitudinal direction to allow longitudinal alignment. In some embodiments, the cross needle 314 and / or the guidewire 316 may be magnetically pulled from the artery 300 to the vein 302, or vice versa. Some systems may have both ultrasonic and magnetic guidance. For example, ultrasonic guidance may be used for initial alignment, and magnetic guidance may be used for precise alignment.

[0287] Referring again to Figures 20A to 20H, as shown in Figure 20F, the prosthesis delivery system 330, which holds the prosthesis 349, tracks along the guidewire 316 through the space between the artery 300 and the vein 302. In some embodiments, a separate PTA balloon catheter (e.g., about 2 mm) can be tracked along the guidewire 316 to pre-dilate the fistula between the artery 300 and the vein 302 before introducing the prosthesis delivery system 330. The use of the PTA balloon catheter may depend, for example, on the radial force of the prosthesis 340.

[0288] The prosthesis 340 is deployed from the prosthesis delivery system 330, for example, by operating the trigger handle 194 (Figure 17). In some embodiments, if the prosthesis 340 cannot be expanded and / or advanced, for example, the prosthesis delivery system 330 may be withdrawn, and a PTA catheter (e.g., about 2 mm) may be advanced along the guidewire 316 to attempt to enlarge or further enlarge the fistula between the artery 300 and the vein 302. The deployment of the prosthesis 340 may then be attempted again (e.g., by self-expansion, balloon expansion, etc.). In some embodiments, the deployment of the prosthesis 340 can remodel the vessel, thereby expanding the diameter of the vessel by at least about 10%, at least about 20%, at least about 30% or more, about 0% to about 10%, about 0% to about 20%, about 0% to about 30% or more. In embodiments where the prosthesis 340 is self-expanding, the degree of remodeling may change over time. For example, the prosthesis 340 expands when blood vessels expand and contracts when blood vessels contract.

[0289] As shown in Figure 20G, once the prosthesis 340 is deployed, the fistula can be enlarged by a PTA catheter. The diameter of the PTA catheter (e.g., approximately 3 mm to 6 mm) can be selected at least partially based on the diameter of the artery 300, the diameter of the vein 302, the composition of the interstitial tissue, the properties of the prosthesis 340, or a combination thereof. In some embodiments, the prosthesis delivery system 330 may comprise a PTA balloon catheter (e.g., proximal or distal to the prosthesis 340) useful for one, more or all of the optional PTA balloon catheterization techniques described herein. In embodiments where the prosthesis has a conical portion, the PTA balloon may also have a conical portion. Once the prosthesis 340 is in place, the prosthesis delivery system 330 can be withdrawn as shown in Figure 20H. This forms an AV fistula between the artery 300 and the vein 302. The placement of intravenous catheters 310, 320, 330 and prosthesis 340 can be confirmed through part or all of the procedure under fluoroscopy with contrast agent injection.

[0290] In some embodiments, a marker (e.g., clip, lancet, scissors, pencil, etc.) can be applied to the skin (e.g., by adhesion, by placing it on top, etc.) to roughly mark the location of the fistula formed between the artery 300 and the vein 302 by the crossing needle 314 before deploying the prosthesis 340. In embodiments where a blood pressure monitor is inflated over the fistula by the user to avoid bleeding, the absence of blood flow may make it difficult to visualize or even evaluate the fistula site, but such identification can be made by the marker. In embodiments where the transmitting / receiving catheter is removed after fistula formation, the intersection may be difficult for the user to perceive or judge by touch, but such identification can be made by the marker. If the fistula is to be enlarged, it is preferable that the midpoint of the enlargement balloon be aligned with the midpoint of the fistula (e.g., to enlarge or maximize the interstitial space penetration hole). In some embodiments, markers can be visualized under fluorescence fluoroscopy (e.g., including radiopaque materials) to allow the user to confirm and remember the location of the fistula under fluorescence fluoroscopy before deploying the prosthesis 340.

[0291] When prosthesis 340 is in place, the obstruction to blood flowing through vein 302 to the leg is the intravenous valve. Manipulating the guidewire across the venous valve can be difficult, for example, because the pressure from the artery may not be sufficient to dilate the vein and disable the valve. As will be described in more detail below, it has been found that the distal venous valve of the AV fistula can be neutralized or disabled using one or more of a variety of techniques, including PTA catheters, stents (e.g., covered stents, stent grafts, etc.) and valve incision knives. By neutralizing the venous valve, it is possible to supply oxygenated blood to the leg in CLI patients by enabling blood flow to the distal part of the leg venous circulation via retrograde perfusion from the femoral artery, retrograde flow within vein 302, and retrograde flow within the vein into the venules and capillaries.

[0292] In some embodiments, venous valves can be rendered inoperable using a high-pressure PTA balloon catheter (for example, when inflated to over approximately 10 atm (approximately 1013 kilopascals (kPa))).

[0293] In some embodiments, one or more stents can be positioned across one or more venous valves to disable them. For example, such stents should have sufficient radial force to keep the valves open. The stents can forcibly tear the valves. In some embodiments, the stents are equipped with a covering or graft. Certain such embodiments can cover collateral venous vessels. In some embodiments, the stents are bare, i.e., without a covering or graft. Certain such embodiments can reduce costs. Venous stents can extend along a certain length of a vein (e.g., the entire length). For example, in some embodiments, the entire length of a PTV is lined with a covering stent that covers collateral venous vessels and tears the venous valves.

[0294] In some embodiments, the venous stent is separate from the fistula prosthesis. A separate venous stent can allow for further flexibility with respect to properties such as dimensions (e.g., length, diameter), material (e.g., whether or not it has a covering or graft), and other characteristics. Figure 31A schematically shows exemplary embodiments of a venous stent 342 and an exemplary embodiment of a separate arteriovenous fistula stent 340. The venous stent 342 may be spaced apart from the fistula stent 340 (e.g., as shown in Figure 31A), abutting against the fistula stent 340, or overlapping, nested, or coaxial with the fistula stent 340 (e.g., the distal segment of the fistula stent 340 is at least partially inside the proximal segment of the venous stent 342, or the proximal segment of the venous stent 342 is at least partially inside the distal segment of the fistula stent 340). In embodiments where the fistula stent 340 and the venous stent 342 overlap, first, the placement of the venous stent 342 ensures that the proximal end of the venous stent 342 facing the direction of retrograde blood flow is covered by the fistula stent 340, thereby reducing or eliminating any interruption of blood flow that may occur due to the distal end of the venous stent 342. In embodiments where the fistula stent 340 and the venous stent 342 overlap, the venous stent 342 can then be positioned through the fistula stent 340 so that both stents 340, 342 can share at least one deployment parameter (for example, by tracking a stent deployment device on the same guidewire). The venous stent 342 can be deployed either before or after the fistula stent 340. The venous stent 342 can have a length of approximately 2 cm to approximately 30 cm (for example, 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, etc.).

[0295] In some embodiments, the venous stent is integrated with the fistula prosthesis. The integrated venous stent can allow for greater flexibility in terms of properties such as dimensions (e.g., length, diameter), materials (e.g., with or without a covering or graft), and other characteristics. Figure 31B schematically shows an exemplary embodiment of an arteriovenous fistula stent 344 with an integrated venous stent. Figure 31C schematically shows an exemplary embodiment of a fistula stent 344 with an integrated venous stent. The stent 344 has a first portion 346 configured to be placed in an artery, a second portion 350 configured to be placed within a certain length of a vein to reinforce that length, and a third portion 348 located longitudinally 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., shown in Figure 31C), the third portion 348 can be tapered. In some embodiments, the portion of the second section 350 configured to line a vein has different properties (e.g., diameter, material, radial stiffness, combination thereof, etc.) from the other portions of the second section 350. The length of the second section 350 can be greater than the length of the first section 346. For example, the second section 350 may have a length configured to line a blood vessel such as a PTV. The second section 350 may have a length of approximately 2 cm to approximately 30 cm (for example, 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, etc.).

[0296] In some in situ bypass procedures, the saphenous vein is attached to an artery in the upper limb and another artery in the lower limb to bypass all occlusions within the artery. In some such procedures, the vein is dissected from the patient, inverted longitudinally, and left positioned so that blood flow is retrograde (relative to the venous valve) rather than being used as a prosthesis. A standard valve incisor can be placed in the saphenous vein from below, advanced to the apex in a collapsed state, released, and then pulled back in an released state, incising the venous valve in the process. The cutting surface of such a valve incisor faces posteriorly to cut when it is retracted during these procedures. Figure 23A is a schematic perspective view of an exemplary embodiment of a valve incisor 400 having a proximal-facing blade 402 that can be used with such procedures.

[0297] In some embodiments of the methods described herein, distal access to the venous valve is unavailable, making it impossible to pull the valve incisor backward, but it is possible to push a retrograde valve incisor forward as described herein. Figure 23B is a schematic perspective view of an exemplary embodiment of a valve incisor 410 that can be used with such a procedure. The retrograde valve incisor 410 has one or more blades 412 (e.g., two to five blades (e.g., three blades)) facing forward, i.e., distally, so that the valve can be incised as the retrograde valve incisor 410 advances distally. At least, retrograde access to the vein to be neutralized has not been recognized as a problem until now, so there has been no prior motivation to reverse the direction of the blades of a valve incisor to create a retrograde valve incisor 410 as described herein. The retrograde valve incisor 410 can track along the guidewire 414, thereby allowing it to advance into the vein to disable the venous valve. After forming a fistula between the artery and the vein as described herein, the fluid flow in the vein is in the opposite direction to the original direction of fluid flow in the vein, i.e., the normal direction i.e., the direction before the procedure. Therefore, pushing the retrograde valve incisor 410 is in the opposite direction to the original fluid flow, but the direction of fluid flow after fistula formation.

[0298] Other systems and methods for disabling intravenous valves may also be considered (e.g., cutting balloons, atherectomy, laser excision, ultrasound excision, heating, radiofrequency (RF) excision, catheters with a traumatic or non-traumatic tip (e.g., introducer sheath) that advances and / or retracts, combinations thereof, etc.).

[0299] It can also be difficult to reverse-cross such valves before rendering them inoperable within a vein. Figure 24 is a schematic perspective view of an exemplary embodiment of a LeMaitre device 420 that can be used to radially dilate a vein and thus its valve. The LeMaitre device 420 has an expandable elliptical or oblong leaf shape 422, which is, for example, a self-expanding nitinol mesh. In some embodiments, a vein and thus its valve can be radially dilated using a PTA balloon catheter. In some embodiments, a vein and thus its valve can be radially dilated by applying a tourniquet to the leg. During radial dilation, a guidewire can be advanced via expansion valves (which may be multiple) (e.g., via dilation devices such as a LeMaitre device), and a catheter (e.g., PTA, stent delivery, atherectomy, etc. (e.g., directional, orbital, laser, etc.)) or other over-the-wire device can be advanced along the guidewire.

[0300] Figures 26A and 26B schematically illustrate another exemplary embodiment of a method for performing retrograde perfusion. Referring again to Figure 20E, a fistula can be formed between artery 600 and vein 602, including the occlusion 604, by inserting a guidewire 606 using one or more techniques and / or other techniques described herein. As shown in Figure 26A, a prosthesis delivery system holding the prosthesis 620 tracks along the guidewire 606 through the space between artery 600 and vein 602. In some embodiments, a separate PTA balloon catheter (e.g., about 2 mm) can be tracked along the guidewire 606 to pre-dilate the fistula between artery 600 and vein 602 before introducing the prosthesis delivery system. The use of a PTA balloon catheter may depend, for example, on the radial force of the prosthesis 620. The prosthesis 620 may be a stent 500, 520, 540 or a variation thereof (for example, as described with respect to Figure 25C) as shown in Figures 25A–25C, which includes uncovered, low-porosity woven filaments configured to bypass blood flow.

[0301] The flow bypass characteristics of uncoated woven filaments may be determined by certain hemodynamic characteristics of the vascular lumen. For example, if the occlusion 604 is not complete and some pressure loss may occur between the lumen of the prosthesis 620 and the portion of artery 600 between the occlusion 604 and the prosthesis 620, blood may flow through the sidewall of the prosthesis 620 rather than through the fistula. Referring again to Figure 4 and the description of the block material 251, the block material 608 can be optionally placed on artery 600 to further occlude artery 600, thereby preventing hemodynamic effects that could cause and / or enable blood flow through the sidewall of the prosthesis 620. In another example, a pressure loss between artery 600 and vein 602 may cause and / or enable blood flow through the sidewall of the prosthesis in the direction of normal venous blood flow rather than through the lumen of the prosthesis to perform retrograde perfusion. Referring again to Figure 4 and the description of the block material 251, the block material 610 can be optionally placed in vein 602 to occlude the downstream portion of the fistula in vein 602, which is under normal venous flow, thereby preventing hemodynamic effects that could cause and / or enable blood flow through the side wall of the prosthesis 620.

[0302] The prosthesis 620 is deployed from the prosthesis delivery system, for example, by operating the trigger handle 194 (Figure 17). In some embodiments, if the prosthesis 620 cannot be expanded and / or advanced, for example, the prosthesis delivery system may be withdrawn and a PTA catheter (e.g., about 2 mm) may be advanced along the guidewire 620 to attempt to enlarge or further enlarge the fistula between the artery 600 and the vein 602. The deployment of the prosthesis 620 may then be attempted again (e.g., by self-expansion, balloon expansion, etc.). In embodiments where the prosthesis 620 is self-expanding, the degree of remodeling may change over time, for example, the prosthesis 620 may expand when the blood vessel expands or contract when the blood vessel constricts. The prosthesis 620 may resemble the anatomical structure into which the prosthesis 620 is deployed. For example, in an expanded state on a table or benchtop, the prosthesis 620 can be substantially cylindrical, but the prosthesis 620 can be adapted to the diameter of the blood vessel and the diameter of the fistula into which the prosthesis 620 is deployed, and the prosthesis can have different diameters in different longitudinal segments, tapered sections, non-cylindrical sections, or combinations thereof.

[0303] In some embodiments of the prosthesis 620 that include an auxiliary support structure (as described, for example, with respect to Figure 25B), the deployment of the prosthesis may include deploying a first woven structure and deploying an auxiliary support structure before, during, and / or after deploying the first woven structure.

[0304] Optionally, the fistula can be enlarged by a PTA catheter before, during, and / or after deployment of the prosthesis 620. The diameter of the PTA catheter (e.g., approximately 3 mm to 6 mm) can be selected at least partially based 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, and combinations thereof.

[0305] Once the prosthesis 620 is in place, the prosthesis delivery system can be withdrawn, as shown in Figure 26B. This creates an AV fistula between the artery 600 and the vein 602. Even if the prosthesis lacks or does not have a graft, blood flows through the lumen of the prosthesis 620 due to its low porosity (e.g., less than about 50% porosity or other values ​​as described herein) hemodynamic action. Figure 26B shows an embodiment without the block materials 608, 610. Once the prosthesis 620 is in place, the valve in the vein can be rendered inoperable, as described herein, for example.

[0306] In embodiments in which the prosthesis 620 includes two or more filaments that can be deployed separately (for example, as described with respect to a particular embodiment in Figure 25B), the filaments can be deployed at least partially simultaneously, sequentially without intervention steps, or sequentially with intervention steps such as the PTA step described herein.

[0307] Figure 27 schematically illustrates another exemplary embodiment of the prosthesis 720 and a method for performing retrograde perfusion. Although some dimensions and an exemplary scale of "10 mm" are given, the shape, dimensions, positional relationships, etc., of the feature parts shown in Figure 27 can be modified. The prosthesis 720 is positioned within the artery 700 and vein 702, spanning the interstitial tissue T between the artery 700 and vein 702, including the occlusion 704. The prosthesis 720 can be positioned using, for example, the method described herein and / or other methods. In some embodiments, the prosthesis 720 is delivered on a guidewire having an outer diameter of 2 Fr (0.67 mm) through a delivery system having an inner diameter of 5 Fr (1.67 mm).

[0308] In some embodiments, the porosity of the first longitudinal section 722, the second longitudinal section 724 and / or the third longitudinal section 726, or one or more of these sections, can be about 0% to about 50%, as described herein, for example, and vary within that range. Blood flow from the artery 700 can be rerouted through the prosthesis 720 into the vein 702 by hemodynamic forces, such as the pressure difference between the artery 700 and the vein 702. The low porosity of the prosthesis 720 allows fluid to flow substantially through the lumen of the prosthesis 720 without substantially perfusing through the sidewalls of the prosthesis 720. In some embodiments, the ends of the prosthesis 720, for example, the proximal and / or distal portions with lower porosity, can be configured to juxtapose the sidewalls of blood vessels, as blood is less likely to flow through these portions.

[0309] The techniques described herein can be useful for forming fistulas between two body cavities in the lower extremities, such as near the heart, in the periphery, or even in the plantar arch. Figures 28A and 28B schematically show the arteries and veins of the foot, respectively. Fistulas or anastomoses can be formed between two blood vessels in the foot. In one example, an artery-to-vein passage is formed from the lateral plantar artery to the lateral plantar vein in the mid-lateral plantar.

[0310] The artery supplying blood to the leg was occluded, and the subintima-space was calcified. A wire was advanced distally and crossed into the adjacent vein. The hole between the artery and vein, for example, a small arteriovenous fistula, should not cause significant injury to the patient (even if it is damaged) at that location and within that location, so it was dilated using a 1.5 mm balloon. After dilation, blood began to flow from the artery to the vein without leakage. After confirming such flow, the space was further dilated using larger balloons (2.0 mm, 2.5 mm, 3.0 mm) at higher pressures (e.g., 20 atm to 30 atm). Surprisingly, leakage was minimal or absent without the placement of a stent, graft, scaffold, or other type of device. The prosthesis-free procedure can reduce cost, manufacturing time, complexity, and combinations thereof. The lateral plantar vein is a very good candidate for supplying blood to that part of the leg because it leads directly to the venous arch of the forefoot. The patient had considerable pain in the foot prior to the procedure, but the pain in the foot disappeared after the procedure. This indicates that it became possible to supply blood by venous retrograde, as described herein. In certain situations, such as hemodialysis, where the distal or lower limb arteries and veins can be described as "glued" to the surrounding tissue (e.g., the mid-lateral plantar arteries and veins), the fistula or anastomosis maintenance device may be optionally omitted.

[0311] In some situations, a fistula or anastomosis retention device can be optionally used. Several fistula retention devices are described herein. Figure 29 schematically shows an exemplary embodiment of an anastomosis device 800. The anastomosis device has a first section 802, a second section 804, and optionally a third section 806 located longitudinally between the first section 802 and the second section 804. The first section 802 may be configured to be placed in a first body cavity (e.g., a blood vessel such as an artery or vein). The first section 802 may have expandable members, barbs, etc. The second section 804 may be configured to be placed in a second body cavity (e.g., a blood vessel such as an artery or vein, which may be of the opposite type to the first body cavity). The third section 806 may be configured to straddle the lumen between the first body cavity and the second body cavity. In some embodiments, the space between the lumens of the first and second body cavities generally includes the blood vessel wall, allowing the dimensions of the third section 806 to be reduced or even omitted.

[0312] Several anastomotic devices are available and / or under development for treating holes in larger blood vessels (e.g., Spyder from Medtronic, CorLink from Johnson and Johnson, Symmetry from St. Jude Medical, PAS-Port from Cardica, and ROX Coupler from ROX Medical). Such devices may be suitable for use in the periphery or lower extremities, for example, if resized and / or reconfigured. Other devices may also be considered.

[0313] Figure 30 schematically shows an exemplary embodiment of two blood vessels 902 and 904 joined together by an anastomosis device 800 that straddles the walls of the blood vessels 902 and 904. Blood vessel 902 is an artery as schematically shown by having a thick wall, and blood vessel 904 is a vein. Other combinations of blood vessels and other body cavities are also conceivable. After a passage 906 is formed between the first blood vessel 902 and the second blood vessel 904, the anastomosis device 800 is deployed, for example, as described herein (e.g., using a wire, a deployable needle, one or more balloons, etc.). For example, the distal end of the deployment system of the anastomosis device 800 can remain in the first blood vessel 902 and be partially inserted into the passage 906. The first section 802 of the anastomosis device 800 can be deployed into the second blood vessel 904 by passing it through the passage 906. When deployed, the first section 802 can self-expand to juxtapose, for example, the wall of the second blood vessel 904. The third section 806 of the anastomosis device 800 can be deployed through the passage 906. When deployed, the third section 806 can self-expand, for example, to juxtapose with the surrounding tissue of the passage 906 and maintain patency through the passage 906. The second section 804 of the anastomosis device 800 can be deployed into the first vessel 902. When deployed, the second section 804 can self-expand, for example, to juxtapose with the wall of the first vessel 902. One or more of the first section 802, the second section 804, and the third section 806 can be expanded using a balloon. Different balloons or a series of balloons can be used for different sections 802, 804, and 806 of the anastomosis device 800.

[0314] Figures 32A to 32D illustrate exemplary methods and apparatus for identifying and avoiding bifurcations 1104 in percutaneous bypass procedures. A first vessel 1000 (e.g., an artery) is occluded by an occlusion 1008. The occlusion 1008 may be partial or complete (e.g., causing severe limb ischemia). A percutaneous procedure, such as those described herein, can bypass the occlusion 1008 using a second vessel 1002 (e.g., a vein). A first catheter 1010 is located within the first vessel 1000. A second catheter 1020 is located within the second vessel 1002. The second vessel 1002 includes a bifurcation 1004 at its junction with a branch or collateral vessel 1006. The first catheter 1010 includes an ultrasonic transmitter 1012 (e.g., a directional transmitter) configured to transmit a signal 1014 to an ultrasonic receiver 1022 (e.g., an omnidirectional receiver) of the second catheter 1020 in the second blood vessel 1002, as described herein, for example. A needle 1016 (Figure 32D) can extend from the first catheter 1010 toward the second blood vessel 1002. In the configuration shown in Figure 32A, if the needle 1016 extends at the same angle as the signal 1014, as described herein, for example (e.g., Figure 3), the needle 1016 can extend into the bifurcation 1004 and the branch vessel 1006. The subsequent navigation of the guidewire through the lumen of the needle 1016 may unfortunately lead to the branch vessel 1006 rather than the second blood vessel 1002. Navigation into the branch vessel 1006 rather than the second blood vessel 1002 may be difficult for the user to detect.

[0315] Figure 32B shows the first step of an exemplary method for diagnosing the presence and / or location of a bifurcation 1004. The expandable member 1024 is expanded, for example, by providing a fluid flow (e.g., saline solution, contrast agent, etc.) through an expansion lumen 1026 that is in fluid communication with the expandable member. In Figures 32A to 32D, the second catheter 1020 includes an integrated expandable member 1024 (e.g., including a balloon) and an expansion lumen 1026. A separate catheter including the expandable member can be used in the second blood vessel 1002. Expansion of the expandable member 1024 occludes the second blood vessel 1002. As indicated by arrow 1027, blood still flows toward the expandable member 1020 from both the proximal end of the second blood vessel 1002 and the branch vessel 1006. The occlusion of the second blood vessel 1002 and the blood still flowing into the second blood vessel 1002 can cause the second blood vessel 1002 to dilate. Dilation of the second blood vessel 1002 can make it easier to target and / or puncture the second blood vessel with the needle 1016.

[0316] Figure 32C shows the introduction of contrast agent 1028 into the second vessel 1002. The contrast agent 1028 can be delivered via an injection port integrated with the second catheter 1020 and / or using a separate catheter within the second vessel 1002. The contrast agent 1028 may include, for example, iodine-based, barium sulfate-based (e.g., for subjects with renal impairment), or combinations thereof, contrast agents or media configured to improve fluoroscopy. The contrast agent 1028 can contribute to the dilation of the second vessel 1002. The contrast agent 1028 flows until it reaches the expandable member 1024, after which it begins to accumulate near the expandable member 1024. Some of the contrast agent 1028 accumulates at the bifurcation 1004, allowing the presence and location of the bifurcation 1004 and / or branch vessels 1006 to be visualized under fluoroscopy. Without the expandable member 1024, the contrast agent 1028 would flow through the second vessel 1002 without indicating the bifurcation 1004 and / or the branch vessel 1006. Knowing the angle of the needle 1016 and the position of the first catheter 1010, the user can determine whether the needle 1016 extends into the bifurcation 1004 and / or the branch vessel 1006. Since this situation generally results in an ineffective bypass, a different puncture site can be selected to form a fistula.

[0317] In Figure 32D, the first catheter 1010 has been retracted by a distance of 1018. The second catheter 1020 can be targeted using the ultrasound signal 1014 (Figure 32A) from the first catheter 1010. The procedure shown in Figures 32B and 32C can be repeated, for example, to search for another bifurcation. Once the user is satisfied that the needle 1016 has punctured the second vessel 1002 at a non-bifurcation location to inhibit or prevent advancement of the needle 1016 into a branch vessel rather than the second vessel 1002, the needle 1016 can exit the first catheter 1010, through the interstitial tissue between the first vessel 1000 and the second vessel 1002, and extend into the second vessel 1002 at a location where the second vessel 1002 does not contain a bifurcation or branch vessel. The needle 1016 can be extended even when the expandable member 1024 is in an expanded or contracted state, or when the second catheter 1020 has been removed from the second blood vessel 1002. In some embodiments, a permanent occlusion plug can be placed in the second blood vessel 1002, for example, as described herein (e.g., Figure 4). A guidewire can be tracked through the lumen of the needle 1016, and by tracking the catheter via the guidewire (e.g., through the first blood vessel 1000, through the fistula, and then through the second blood vessel 1002), other procedures described herein, such as fistula dilation, deployment of a fistula prosthesis, deployment of a stent graft, and use of a retrograde valve incision knife can be performed. In some embodiments, the needle can be guided to the bifurcation and / or branching vessels, if desired by the user, using the apparatus and methods described herein.

[0318] Figures 33A and 33B schematically illustrate exemplary procedures in which the following connection of a first vessel 1100 (e.g., an artery) and a second vessel 1102 (e.g., a vein) can be performed using a needle 1116 that crosses interstitial tissue 1101. The needle 1116 extends from a first catheter 1110 within the first vessel 1100. The first vessel 1100 is occluded by an occlusion 1108. In Figure 33A, a guidewire 1118 can extend through the lumen of the needle 1116 and then be navigated through the second vessel 1102. The needle 1116 can be retracted when the guidewire 1118 is positioned, and the first catheter 1110 can be retracted from the first vessel 1100. As shown in Figure 33B, the second catheter 1120 can be tracked along the guidewire 1118 through the first vessel 1100, through the interstitial tissue 1101, and into the second vessel 1102. In Figure 33B, the second catheter 1120 includes a balloon catheter containing a balloon 1122 (e.g., a PTA balloon). Inflation of the balloon 1122 can enlarge the fistula formed between the first vessel 1100 and the second vessel 1102. Enlargement of the openings in the interstitial tissue 1101 and / or vessels 1100, 1102 can enhance subsequent procedures, such as the placement of a prosthesis across the fistula.

[0319] Figures 34A to 35F show exemplary procedures that can be performed when the guidewire 1118 is inside a blood vessel 1102 (e.g., a vein). In Figure 34A, the prosthesis 1124 is positioned across the interstitial tissue 1101 between the first blood vessel 1100 and the second blood vessel 1102. The deployment system for positioning the prosthesis 1124 may be tracked via the guidewire 1118. The catheter 1130A is tracked along the guidewire 1118 distal to the prosthesis 1124. As shown in Figure 34B, the catheter 1130A can be tracked all the way towards the heel 1103 of the target.

[0320] As shown in Figure 34C, catheter 1130A is configured to deliver a first stent graft 1132A that can, for example, line the second vessel 1102, disable the valve of the second vessel 1102, or occlude a branch vessel of the second vessel 1102, as described above. In Figure 34D, catheter 1130A is retracted, and another catheter 1130B is tracked on guidewire 1118. Figure 34D also shows an example in which an occlusion 1108 in the first vessel 1100 can be terminated, which can be useful if another fistula is formed between the first vessel 1100 and the second vessel 1102 (for example, to bypass the occlusion 1108). Forming the second fistula may be the same as or different from forming the first fistula (e.g., using at least one ultrasound guidance, needle extension, and prosthesis deployment as described herein). In Figure 34E, catheter 1130B delivers a second stent graft 1132B that can at least partially overlap the first stent graft 1132A in region 1133. In some embodiments, the distal end of the second stent graft 1132B may be configured to overlap the proximal end of the first stent graft 1132A. In some embodiments, the proximal end of the first stent graft 1132A may be configured to overlap the distal end of the second stent graft 1132B. In some embodiments, for example, when the second stent graft 1132B is initially placed, the proximal end of the first stent graft 1132A may be configured to overlap the distal end of the second stent graft 1132B. The second stent graft 1132B can be spaced longitudinally from the first stent graft 1132A, for example, if the longitudinal spacing is sufficiently small and it is unlikely that branch vessels and / or valves will be present in that space.

[0321] In Figure 34F, the second stent graft 1132B overlaps with the prosthesis 1124 at least partially. In some embodiments, the proximal end of the second stent graft 1132A can be configured to overlap with the distal end of the prosthesis 1124. In some embodiments, the distal end of the prosthesis can be configured to overlap with the proximal end of the second stent graft 1132B. The second stent graft 1132B can be spaced longitudinally from the prosthesis 1124, for example, if the longitudinal spacing is sufficiently small and it is unlikely that branch vessels and / or valves will be present at that spacing. Figure 34F also shows the catheter 1132B retracted from the vascular system. Although two stent grafts 1132A and 1132B are described in this embodiment, one, two, three, or more stent grafts can be used depending on, for example, the length of the second vessel 1102 distal to the prosthesis 1124, the length of the stent graft, the possibility or presence of branch vessels, etc.

[0322] Figure 35A shows a second vessel 1102 distal to the first stent graft 1132A. The second vessel 1102 includes a first valve 1105A that obstructs or prevents blood 1111 from flowing distal to the first valve 1105A. In Figure 35B, a catheter 1140 is tracked on a guidewire 1118 through the stent graft 1132A toward the first valve 1105A. The catheter 1140 includes a valve deactivation device. In Figure 35C, the catheter 1140 is shown including a retrograde valve incisor 1142, as described herein, for example, and a sheath 1144. Referring again to Figure 35B, the retrograde valve incisor 1142 is in a radially contracted state when it is inside the sheath 1144. As shown in Figure 35C, as the sheath 1144 retracts proximal and / or the retrograde valve incisor 1142 advances distally, the retrograde valve incisor 1142 expands radially to a state configured to cut the valve during distal advancement. In Figure 35D, one or more blades of the retrograde valve incisor 1142 excise, cut or cleave the leaflets of the first valve 1105A, allowing blood 1111 to flow distally to the first valve 1105A.

[0323] Referring to Figure 35E, after the first valve 1105A is disabled, the retrograde valve incisor 1142 can be compressed radially within the outer sheath 1144 to advance further distally without affecting the second vessel 1102. As shown in Figure 35F, upon encountering the second valve 1105B, the retrograde valve incisor 1142 extends from the sheath 1144 and then advances distally to disable the second valve 1105B, allowing blood 1111 to flow distal to the second valve 1105B. The use of the retrograde valve incisor 1142 can be repeated for as many valves in the second vessel 1102 as the user desires. In some embodiments, the retrograde valve incisor 1142 can be used before the placement of stent grafts 1132A, 1132B. For example, valve deactivation devices other than retrograde valve cutting knives may also be used, or may be used as alternatives, although they are not limited to the bidirectional valve cutting knife 1300 described herein.

[0324] Figures 36A to 36D illustrate how retrograde perfusion of blood through veins to the toes can be facilitated. In Figure 36A, the illustrated vascular system includes the lateral plantar vein 1200, the deep plantar arch 1202, the metatarsal vein 1204, and the medial plantar vein 1206. As indicated by arrow 1201, the blood flow through the lateral plantar vein 1200 is in the opposite direction to the normal flow due to retrograde perfusion caused, for example, by a percutaneous bypass from an artery to a vein upstream of the lateral plantar vein 1200. The blood continues to flow through the vascular system as indicated by arrow 1203, where the blood is joined by the blood flowing away from the toes in the normal direction of blood flow through the metatarsal vein 1204 as indicated by arrow 1205. The medial plantar vein 1206 is configured to return blood towards the heart, so normal blood flow is maintained as indicated by arrow 1207. As shown in Figure 36A, blood may flow preferentially, which is undesirable if the intended effect of retrograde perfusion is to perfuse oxygenated blood to the toes.

[0325] Figure 36B shows an exemplary embodiment of a device that can be used to facilitate blood flow to the toes through the metatarsal vein 1204. A first catheter 1210, including a first inflatable member 1212 (e.g., a balloon), may include a 6-French occlusive catheter with a three-way fitting. The inflatable member 1212 is inflated within the lateral plantar vein 1200. A second catheter 1220, coaxial with the first catheter 1210, extends through the inflatable member 1212, through the deep plantar vein arch 1202, and into the medial plantar vein 1206. The second catheter 1220 includes an inflatable member 1222 (e.g., a balloon) that can be inflated within the medial plantar vein 1206. At that point, the medial planar vein 1206 is partially or completely occluded, and blood flow through the medial plantar vein 1206 is inhibited or prevented. Blood can continue to flow from the toes through the metatarsal vein 1204, as indicated by the persistence of arrow 1205. Because blood has no exit pathway, hydrostatic pressure may accumulate in the deep plantar vein arch 1202, which may disable valves and / or other structures configured to promote normal blood flow. If necessary, the first expandable member 1212 can allow retrograde perfusion blood to flow, which can build up further pressure within the deep plantar vein arch 1202. Blood flow normally perfuses in the opposite direction to retrograde perfusion in the lateral plantar veins 1200, but the expandable member 1212 can obstruct or prevent such flow.

[0326] In some embodiments, a device including a single catheter can be used to facilitate blood flow to the toes through the metatarsal vein 1204. The device may include a first expandable member and a second expandable member. For example, the device may include a double-balloon catheter having a first balloon and a second balloon distal to the first balloon.

[0327] The device may allow one of the first and second expandable members to inflate independently of the other expandable member. For example, in some embodiments, the device may include at least a first lumen and a second lumen. The first lumen may be configured to inflate the first expandable member independently of the second expandable member. The second lumen may be configured to inflate the second expandable member independently of the first expandable member. The device may include a single lumen configured to inflate both the first and second expandable members. The device may include one or more expansion ports configured to inflate at least one of the first and second expandable members.

[0328] The device may be configured to adjust the distance between expandable members before at least one of the expandable members inflates. The device may allow the expandable members to isolate patient-specific treatment areas and facilitate retrograde perfusion of blood through the veins to the toes, as described herein. For example, the device may allow the placement of a first expandable member to the lateral plantar vein 1200 and a second expandable member to the medial plantar vein 1206, and / or vice versa. The device may include one or more handles configured to control the movement of different parts of the device. For example, the device may include a first handle for controlling the movement of both the first and second expandable members. In some embodiments, the device may include a second handle configured to control the movement of the first expandable member independently of the second expandable member. The second handle may allow the device to advance the first expandable member from a first position to a second position proximal to the second expandable member. After the first expandable member has been advanced to the second position, the second handle can enable the device to advance the first expandable member distally to the first position.

[0329] The device may include an injection port configured to inject fluid into a treatment area defined by first and second expandable members. For example, the treatment area may include a deep plantar vein arch 1202. After the first and second expandable members are inflated, blood flow through the medial plantar vein 1206 is obstructed or prevented. The injection port may then allow the device to inject fluid into the treatment area. The injection of fluid may increase the hydrostatic pressure within the treatment area. The inflated first and second expandable members increase to prevent the injected fluid from flowing out of the treatment area through the medial plantar vein 1206 and / or the lateral plantar vein 1200. The injection port may be configured to increase the hydrostatic pressure within the treatment area sufficiently so that the device can disable valves and / or other structures. For example, the injection port may be sized to inject a sufficient amount of fluid to increase the hydrostatic pressure to promote blood flow to the toes.

[0330] In Figure 36C, as indicated by arrow 1201, blood flow is able to pass through the expandable member 1212, but the expandable member 1212 obstructs normal blood flow in the deep plantar venous arch 1202. The pressure due to the restricted flow accumulates in the deep plantar venous arch 1202. This pressure accumulation, combined with blood flow from the lateral plantar vein 1200 as needed, can cause a backflow of blood into the metatarsal vein 1204, as indicated by arrow 1209.

[0331] In Figure 36D, the first catheter 1210 and the second catheter 1220 have been removed. Disabling of the normal vascular system in the deep plantar vein arch 1202 causes continuous retrograde perfusion of blood through the metatarsal vein 1204, as indicated by the maintenance of arrow 1209. A small amount of oxygenated blood can flow through the medial plantar vein 1206. In some embodiments, the medial plantar vein 1206 can be left occluded using an expandable member 1222 (e.g., detachable from catheter 1220) or a different occluder. In some embodiments, blood can flow through the plantar vein 1206 in the opposite direction to normal blood flow.

[0332] Figure 37A shows an example of a valve deactivator 1300 in a radially expanded state. The valve deactivator 1300 is configured to cut, excise, sever or deactivate the valve leaflets of a valve (e.g., a venous valve) when it retracts and / or advances in a radially expanded state. The valve deactivator 1300 includes a proximal portion 1308, a distal portion 1306, and an intermediate portion 1302 between the proximal portion 1308 and the distal portion 1306. The proximal portion 1308 includes a tubular element. The distal portion 1306 includes a tubular portion. The device 1300 can be formed by cutting (e.g., laser cutting) hypotube, cutting a flat sheet and rolling it into hypotube, forming the parts of the device 1300, then joining the parts together, shaping them, and combining them, etc. The tubular elements of the distal portion 1306 and / or the tubular elements of the proximal portion 1308 may include uncut portions of hypotube or sheet.

[0333] The proximal portion 1308 can be coupled to a pusher eleme...

Claims

1. A device that disables valves in blood vessels, A mesh structure having multiple interconnected struts, which is expandable from a compressed position within a delivery catheter to an expanded position within the blood vessel, A plurality of blades, each of which extends from each of the plurality of struts, Equipped with, The mesh structure is configured to move through the blood vessel in an expanded state, and the plurality of blades cut at least partially the valve, rendering the valve non-functional. Device.

2. The plurality of blades are arranged around the mesh structure at equal intervals in the circumferential direction. The apparatus according to claim 1.

3. The aforementioned plurality of blades include four blades, The apparatus according to claim 1.

4. The plurality of blades are arranged around the mesh structure at equal intervals of 90 degrees in the circumferential direction. The apparatus according to claim 3.

5. The first blade among the plurality of blades is offset longitudinally along the mesh structure with respect to the second blade among the plurality of blades. The apparatus according to claim 1.

6. The plurality of blades are formed integrally with each of the corresponding plurality of struts. The apparatus according to claim 1.

7. Each of the plurality of blades extends circumferentially with respect to the longitudinal axis of the mesh structure, and the plurality of blades do not cut the blood vessel when the mesh structure is in the expanded state within the blood vessel. The apparatus according to claim 1.

8. Each of the aforementioned plurality of blades has a curved shape, The apparatus according to claim 1.

9. The plurality of blades are configured to at least partially cut the valve and render it non-functional as the mesh structure moves proximal through the blood vessel. The apparatus according to claim 1.

10. The plurality of blades are configured to at least partially cut the valve and render it non-functional as the mesh structure moves distally through the blood vessel. The apparatus according to claim 1.

11. The plurality of blades are configured to at least partially cut the valve and render it non-functional as the mesh structure moves proximal through the blood vessel and is pushed distally through the blood vessel. The apparatus according to claim 1.

12. The mesh structure is configured to self-expand from the compression position to the expansion position. The apparatus according to claim 1.

13. The mesh structure includes a cut hypo tube. The apparatus according to claim 1.

14. The valve is a venous valve. The apparatus according to claim 1.

15. The delivery catheter and the mesh structure are movable relative to each other, and the mesh structure can be moved away from the delivery catheter, allowing the mesh structure to expand from the compressed position to the expanded position. The apparatus according to claim 1.

16. The delivery catheter further includes, The apparatus according to claim 15.

17. A device that disables valves in blood vessels, A mesh structure having multiple interconnected struts, which is expandable from a compressed position within a delivery catheter to an expanded position within the blood vessel, A plurality of blades, each of which extends from each of the plurality of struts, An elongated member extending from the mesh structure, wherein the elongated member is configured to move such that the mesh structure moves while the mesh structure is in an expanded state within the blood vessel, and the plurality of blades cut the valve at least partially, thereby rendering the valve non-functional, Equipped with, Device.

18. The plurality of blades include four blades, and the plurality of blades are arranged at equal intervals in the circumferential direction around the mesh structure. The apparatus according to claim 17.

19. The first blade among the plurality of blades is offset longitudinally along the mesh structure with respect to the second blade among the plurality of blades, and the plurality of blades are integrally formed with each of the corresponding plurality of struts. The apparatus according to claim 17.

20. Each of the plurality of blades extends circumferentially with respect to the longitudinal axis of the mesh structure, and is configured such that the plurality of blades do not cut the blood vessel when the mesh structure is in the expanded state within the blood vessel, and each of the plurality of blades has a curved shape. The apparatus according to claim 17.

21. The plurality of blades are configured to at least partially cut the valve and render it inoperable when the elongated member is pulled in the proximal direction and when the elongated member is pushed in the distal direction. The apparatus according to claim 17.

22. The elongated member includes a hypotube, and the mesh structure includes a cut hypotube. The apparatus according to claim 17.

23. The valve is a venous valve, and the blood vessel is a vein in the patient's lower leg. The apparatus according to claim 17.

24. The delivery catheter and the mesh structure are movable relative to each other, and the mesh structure can be moved away from the delivery catheter, allowing the mesh structure to expand from the compressed position to the expanded position. The apparatus according to claim 17.

25. A device that disables valves in blood vessels, A single, integrated structure comprising multiple interconnected struts, extending along a longitudinal axis, and expandable from a compressed position within a delivery catheter to an expanded position within the blood vessel, A plurality of blades, each of which extends from each of the plurality of struts and is arranged substantially equally spaced circumferentially around the longitudinal axis in the extended position, Equipped with, The integral structure is configured to move through the blood vessel in an expanded state, and the plurality of blades cut at least partially the valve to render the valve non-functional. Device.

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