Methods and systems for providing or maintaining fluid flow through a body passage

Abstract

The present invention is entitled "Methods and systems for providing or maintaining fluid flow through a body passageway". An apparatus includes a first end, a second end, a middle portion, and a graft material. The first end has a first end diameter. The second end has a second end diameter that is smaller than the first end diameter. The first end includes a first material. The second end includes a second material different from the first material. The middle portion is between the first end and the second end. The middle portion tapers between the first end and the second end. The graft material is bonded to at least the middle portion.

Description

[0001] This application is a divisional application. The application date of the original application is February 28, 2014, the application number is 201710630079X, and the name of the invention is “Methods and systems for providing or maintaining fluid flow through a body channel”.

[0002] Incorporated by Reference

[0003] U.S. patent application No. 13 / 791,185, filed on March 8, 2013, U.S. Provisional Patent Application No. 61 / 901,753, filed on November 8, 2013, U.S. patent application No. 11 / 662,128, filed on January 3, 2008, U.S. patent application No. 14 / 141,913, filed on December 27, 2013, and U.S. patent application No. 12 / 297,498, filed on February 25, 2009, which was the national phase of PCT / GB2007 / 001430, filed on April 20, 2007, and published as U.S. patent application No. 8,439,963 on May 14, 2013, are hereby incorporated by reference in their entirety. background Technical Field

[0005] The present application relates to methods and systems for use in percutaneous interventional 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.

[0006] Description of Related Art

[0007] Minimally invasive percutaneous surgery or "keyhole" surgery is a surgical technique in which surgical devices are inserted into a patient's body cavity through a small hole cut in the skin. This form of surgery has become increasingly popular because it allows patients to endure less surgical discomfort while maintaining the benefits of traditional surgery. Patients treated with this technique are exposed to lower levels of discomfort, the need for general anesthesia, risk of trauma and infection, and their recovery time can be significantly reduced compared to traditional surgical procedures.

[0008] For example, keyhole surgery can be used for laparoscopic surgery and for the treatment of cardiovascular disease. In the treatment of cardiovascular disease, balloon angioplasty can be used as an alternative to open heart surgery for the treatment of partially occluded coronary arteries, in which a balloon catheter is inserted into an artery usually near the patient's groin and is guided to the patient's heart, where the balloon at the distal end of the catheter is inflated to widen or expand the occluded blood vessels to help restore blood flow to the heart tissue. Tubular support devices (e.g., stents) can be deployed at the site of obstruction to prevent future occlusion (restenosis) or collapse of blood vessels. For example, stents can be expandable metal mesh tubes carried on the balloon of a balloon catheter, or can be self-expanding. When the balloon is expanded, the balloon expandable stent expands so that the stent pushes the vessel wall. When the stent reaches its expanded position, for example, by plastic deformation or by means of a mechanical locking mechanism, the stent is arranged to maintain its expanded shape, thereby forming an elastic stent or support in the blood vessel. The support framework (e.g., stent) supports the vessel wall and expands the vessel wall to maintain the path of blood flow through the vessel. Self-expanding stents are also available that are held in a collapsed state by an appropriately modified catheter for transport through an artery and that adopt an expanded state when deployed at the site of the blockage. For example, the catheter may include a retaining sleeve that holds the stent in a compressed or unexpanded state. Once the sleeve is removed or retracted from the stent, the stent expands to support and dilate the vessel wall.

[0009] Balloon angioplasty is not always an appropriate measure, for example, in acute cases and in cases of complete occlusion of a coronary artery. In these cases, the usual treatment is coronary artery bypass. Coronary artery bypass surgery is an open-chest or open-heart procedure and typically involves grafting a piece of healthy blood vessel onto a coronary artery to bypass the blockage and restore blood flow to the coronary tissue. The healthy blood vessel is typically a vein obtained from the patient's leg or arm during the procedure of the bypass surgery. In order to perform the procedure, the patient's heart must be exposed by opening the chest, separating the sternum, and cutting the pericardium surrounding the heart, which results in significant surgical trauma.

[0010] Traditional coronary artery bypass surgery is not always an option. Certain patients are not good candidates for traditional coronary artery bypass surgery due to low expectations or high risk of recovery from the significant trauma caused by the surgery, high risk of infection, lack of healthy blood vessels for bypass grafts, significant comorbidities, and the expected long and complicated recovery time associated with open-heart surgery. For example, factors such as diabetes, age, obesity, and smoking may exclude a subset of candidate patients who truly need this treatment. Summary of the invention

[0011] The present application provides methods and systems for overcoming certain deficiencies and / or improving percutaneous methods and systems. For example, according to several embodiments, the methods and systems described herein can improve the targeting and positioning of therapeutic administration, which can advantageously provide treatment to patients who are not suitable for more invasive surgery via percutaneous techniques. Certain embodiments described herein can provide fluid flow in channels such as coronary and / or peripheral blood vessels by creating bypasses using minimally invasive percutaneous surgical techniques.

[0012] In some embodiments, a method of redirecting fluid flow from a first channel to a second channel includes deploying a device in a third channel between the first channel and the second channel. The device includes a first end, a second portion, a middle portion, and a graft material. The first end has a first terminal diameter. The second end has a second terminal diameter greater than the first terminal diameter. The middle portion is located between the first end and the second end. The middle portion tapers between the first end and the second end. The graft material is bonded to at least the middle portion. The method further includes expanding the first end against a side wall of the first channel and expanding the second end against a side wall of the second channel.

[0013] The first channel may be an artery and the second channel may be a vein. The first channel may be a coronary artery and the second channel may be a coronary vein. The method may further include expanding a third channel. The first channel may be a peripheral artery and the second channel may be a peripheral vein. The method may further include expanding the third channel. Expanding the third channel may include expanding a middle portion. The first channel may be substantially parallel to the second channel. The middle portion may conform to an "S" shape. Expanding the first end and the second end may include self-expanding the first end and the second end. Expanding the first end and the second end may include expanding at least one balloon of the first end and the second end. Expanding one of the first end and the second end may include self-expanding one of the first end and the second end and expanding the other of the first end and the second end may include expanding another balloon of the first end and the second end. The method may further include expanding the middle portion.

[0014] In some embodiments, the device includes a first end, a second end, a middle portion, and a graft material. The first end has a first end diameter. The second end has a second end diameter that is smaller than the first end diameter. The middle portion is located between the first end and the second end. The middle portion tapers between the first end and the second end. The graft material is at least bonded to the middle portion.

[0015] At least one of the first end and the second end may be generally cylindrical. The first end may be generally cylindrical and the second end may be generally cylindrical. The first end may taper between the first terminal diameter and the middle portion or the second end may taper between the second terminal diameter and the middle portion. The first end may taper between the first terminal diameter and the middle portion and the second end may taper between the second terminal diameter and the middle portion. The first end may include a first type of material, the second end may include a second type of material, and the middle portion may include a third type of material. The first type of material may include a first cutting material, the second type of material may include a second cutting material, and the third type of material may include a filament. The first cutting material may include a chromium-cobalt alloy, the second cutting material may include nitinol, and the filament may include nitinol. The first type of material may include a cutting material, the second type of material may include a cutting material, and the third type of material may include a filament. The cutting material may include nitinol and the filament may include nitinol. At least one of the first end, the second end, the middle portion, and the graft material may include a bioabsorbable material. At least some of the graft material may be outside the middle portion. At least some of the graft material may be inside the middle portion. At least some of the graft material may be embedded within the middle portion. The device may be capable of maintaining or configured to maintain fluid flow between a first channel in which the first end is fixed and a second channel in which the second end is fixed. The first channel may be substantially parallel to the second channel. The middle portion may conform to an "S" shape.

[0016] In some embodiments, the device includes a first end, a second end, a middle portion, and a graft material. The first end includes a first material. The second end includes a second material different from the first material. The middle portion is located between the first end and the second end. The graft material is at least bonded to the middle portion.

[0017] The first material may include nitinol and the second material may include chrome cobalt. The first material may include nitinol and the second material may include stainless steel. The first end may include a cutting strut and the second end may include a filament. The first end may include a cutting strut and the second portion may include a cutting strut. The first material may include an alloy and the first end may include a strut or filament having a first thickness, and the second material may include an alloy and the second end may include a strut or filament having a second thickness different from the first thickness. The middle portion may include a third material. The third material may include nitinol. The middle portion may include a filament. The middle portion may include a cutting strut. At least one of the first end and the second end may be generally cylindrical. At least one of the first end, the second end, the middle portion, and the graft material may include a bioabsorbable material. At least some of the graft material may be outside the middle portion. At least some of the graft material may be inside the middle portion. At least some of the graft material may be embedded within the middle portion. The graft material may be bonded to at least one of the first end and the second end. The device may be capable of maintaining or configured to maintain fluid flow between a first channel in which the first end is fixed and a second channel in which the second end is fixed. The first channel may be substantially parallel to the second channel. The middle portion may conform to an "S" shape.

[0018] In some embodiments, the device includes a support structure and a graft material. The support structure includes a first end, a second end, and a middle portion between the first end and the second end. At least one of the first end, the second end, and the middle portion includes a cutting strut and at least one of the first end, the second end, and the middle portion includes a filament. The graft material is bonded to at least the middle portion.

[0019] The first end and the second end may include a cutting strut and the middle portion may include a filament. At least some of the graft material may be outside the middle portion. At least some of the graft material may be inside the middle portion. At least some of the graft material may be embedded in the middle portion. The graft material may be attached to at least one of the first end and the second end. The device may be capable of maintaining or configured to maintain a fluid flow between a first channel and a second channel, in which the first end is fixed and in which the second end is fixed. The first channel may be substantially parallel to the second channel. The middle portion is consistent with an "S" shape.

[0020] The device may have a diameter between about 1 mm and about 12 mm (e.g., between 2 mm and 6 mm). The device may have a diameter between about 1 mm and about 10 mm (e.g., between 4 mm and 8 mm). The device may have a diameter between about 6 mm and about 25 mm (e.g., between 12 mm and 15 mm). The device may have a diameter between about 20 mm and about 50 mm (e.g., between 35 mm and 40 mm). The device may have a length between about 25 mm and about 150 mm (e.g., between 70 mm and 110 mm). The device may include a filament having a diameter between about 0.001 inch and about 0.01 inch (e.g., between 0.003 inch and 0.006 inch). The device may include a pillar having a diameter between about 0.001 inch and about 0.01 inch (e.g., between 0.003 inch and 0.006 inch).

[0021] In some embodiments, a device for providing or maintaining fluid flow through at least one passageway in a human or animal body comprises two ends for fixing the device in place and a middle portion for allowing the ends to move relative to each other. The ends and the middle portion together define a path for the fluid flow through the device.

[0022] By moving the two ends relative to each other, the device can respond to movement of one or more channels in which the device is used. The middle portion can be flexible to allow relative movement of the ends. In some embodiments, the device has varying or different flexibility along the length of the device or along the length of a portion of the device. For example, because the magnitude of stress within the middle portion can be relatively low compared to stress on a support structure (e.g., a stent) having uniform flexibility along its entire length, device flexibility can reduce the likelihood of device failure due to fatigue.

[0023] The device can be configured to provide or maintain fluid flow through a single passage, such as an occluded blood vessel. The middle portion can be capable of maintaining or configured to maintain fluid flow between the proximal and distal portions of the occluded blood vessel. The middle portion can pass through a further passage extending between the proximal and distal portions of the blood vessel, such as the exterior of the blood vessel. The device can be configured to act as a bypass between the proximal and distal portions of a single blood vessel, such as an artery or vein.

[0024] The device can be configured to provide fluid flow from an occluded blood channel to another channel. The channels can be interconnected by passing through a middle portion of a further channel extending between the two channels. The device can be configured to be used as a shunt between two channels, such as between an artery and a vein.

[0025] In embodiments where the ends can move relative to each other via an intermediate portion, the device can be suitable for use in applications where the ends are fixed in separate channels that move relative to each other. Regardless of the relative movement of the ends, the path for fluid communication is maintained through the device, and the likelihood of fatigue failure of the device due to cyclic movement of the ends can be low compared to a support structure (e.g., a stent) lacking such an intermediate portion.

[0026] One or both of the ends may be diametrically expandable to secure the device in place. For example, the expanded ends may be expandable to meet with and compress the inner sidewalls of the channel to inhibit or prevent substantial sliding or rotation of the ends within the channel, and / or to expand the channel. For example, the middle portion may be diametrically expandable to expand the fluid flow path.

[0027] The device can be in the form of a tube that defines a cavity configured to serve as a fluid flow path. In some embodiments, the tube can be fluid-tight, thereby restricting the fluid flow within the cavity of the tube. The tube can include, but is not limited to, a polymeric material, such as a biocompatible polymer such as polytetrafluoroethylene (PTFE) or a polyurethane such as a polycarbonate aromatic biodurable thermoplastic polyurethane elastomer (e.g., ChronoFlex 80A and 55D are medical grades available from AdvanSource Biomaterials of Wilmington, Massachusetts).

[0028] The device may include a support structure supporting the end portions. The support structure may support the middle portion, in which case the support structure may be flexible within the middle portion to allow the end portions to move relative to each other.

[0029] When a support structure is provided, the support structure or part thereof may be embedded within the wall of the tube.Alternatively or additionally, the structure or part of the structure may be located on the exterior of the tube or within the lumen of the tube.

[0030] The support structure may include at least one mesh. For example, a single mesh may extend along the entire length of the device. In another example, each end of the device includes a mesh, in which case the mesh may not stop at the middle portion or may extend into the middle portion. When the mesh is present in the middle portion, the mesh may have a higher density or a smaller window size (e.g., a smaller interval between the fine lines and / or pillars of the mesh) in the end portion than in the middle portion, so that the device is relatively more flexible in the middle portion than in the end portion. By not having a mesh, or even when including a mesh with substantially uniform or uniform density or window size (e.g., due to factors other than mesh density or window size), or by including a mesh with non-uniform density, the device may be relatively more flexible in the middle portion than in the end portion.

[0031] At least one mesh may include a biocompatible metal wire. For example, the metal wire may be stainless steel. Alternatively or additionally, at least one mesh may include a shape memory material, such as nitinol and / or chrome cobalt. When a shape memory material is used, at least a portion of the device may be self-expanding.

[0032] One or both ends may include protrusions or barbs that are capable of being fixed and / or configured to dig into or grip the inner wall of the channel, for example to prevent or reduce sliding or other movement of the or each end relative to the channel.

[0033] The two ends may have different diameters so that the device can be made to fit securely in a channel of variable diameter when the channels have different diameters, or to fit one end in a first channel and the other end in a second channel. The device can be configured for a specific application and / or for a specific patient.

[0034] In some embodiments, a method of diverting fluid flow from a first channel to a second channel (e.g., adjacent to the first channel) includes forming a third channel between the first and second channels, providing a device having two ends and a middle portion, deforming the middle portion of the device to allow the device to be inserted into the channel, and expanding the ends against the walls of the first and second channels to secure the device in the channel. The middle portion of the device can be bent to allow the device to be inserted into the channel. The two ends and the middle portion can be configured to maintain or provide fluid flow through the device.

[0035] One or more ends of the device may be expanded by a balloon catheter.Alternatively, or in addition, at least one end may be self-expanding, in which case the method may comprise providing the device in a retaining sheath, and removing the retaining sheath to enable expansion of the at least one end.

[0036] The method may further include expanding the intermediate portion to enlarge the third channel, thereby forming a larger path for fluid flow from the first channel to the second channel.

[0037] The method described herein can be used in many surgical procedures and can be performed by minimally invasive (keyhole) techniques. The method can be particularly suitable for treating coronary heart disease, such as by providing a shunt or bypass to divert arterial blood from an occluded coronary artery to a coronary vein (e.g., adjacent to a coronary artery) and / or by passing through an artery that leaves the proximal end of the occlusion, extending through the subintimal tissue, external tissue and / or a portion of the proximal blood vessel, and re-entering the coronary artery at the distal end of the occlusion to cross the occlusion in the coronary artery; suitable for peripheral vascular disease such as critical limb ischemia, such as by providing a shunt or bypass to divert arterial blood from an occluded peripheral artery to a peripheral vein and / or by passing through an artery that leaves the proximal end of the occlusion, extending through the subintimal tissue, external tissue and / or a portion of the proximal blood vessel, and re-entering the blood vessel at the distal end of the occlusion to cross the occlusion in the peripheral blood vessel; and / or suitable for non-occluded blood vessels, such as by establishing a shunt between a healthy artery and a healthy vein that can be used for dialysis access.

[0038] In some embodiments, the method of treating coronary heart disease comprises diverting arterial blood from a coronary artery to a coronary vein by a method described herein. In some embodiments, the method of treating critical limb ischemia comprises diverting arterial blood from a peripheral artery to a peripheral vein by a method described herein.

[0039] In some embodiments, a method of accessing a target vein includes inserting a needle into the target vein and inserting a guide wire through the needle into the target vein.

[0040] The target vein may be the proximal tibial vein. The method may further include advancing the catheter over the second guidewire. The guidewire may include an ultrasound receiving transducer. The method may further include advancing the guidewire in the direction of blood flow in the target vein. The method may further include inserting a guide sheath into a second vein upstream of the target vein. The method may further include inserting a second guidewire into the second vein. The second guidewire may include an ultrasound receiving transducer. The method may further include at least one of: snaring the guidewire with a second guidewire or a snare and snaring the second guidewire with the guidewire, and pulling the second guidewire in a direction opposite to the blood flow into the target vein. The snaring guidewire may include injecting a contrast and using fluoroscopy for visualization. The method may further include advancing the catheter over the second guidewire. The catheter may include an ultrasound receiving transducer.

[0041] In some embodiments, a device for causing incompetent vascular valves includes a proximal portion, a distal portion, and a longitudinal axis between the proximal portion and the distal portion. The distal portion may include at least one blade. The at least one blade may have a retracted position and an expanded position, wherein the at least one blade is substantially parallel to the longitudinal axis in the retracted position and the at least one blade is substantially non-parallel to the longitudinal axis in the expanded position. The at least one blade may include a sharp surface facing distally and configured to at least partially ablate the valve during distal advancement of the device.

[0042] The at least one blade may include a plurality of blades. The plurality of blades may include three blades. The three blades may be circumferentially spaced approximately 120 degrees apart. The proximal portion may include a handle configured to operate the at least one blade between a retracted position and an expanded position. The at least one blade may include a shape memory material. The handle may be configured to self-expand the at least one blade from the retracted position to the expanded position. The handle may be configured to longitudinally compress and radially expand the at least one blade from the retracted position to the expanded position. The kit may include a device and a vascular dilation device. The vascular dilation device may include at least one of a tourniquet, a balloon, and a LeMaitre device.

[0043] In some embodiments, a method of causing valvular insufficiency in a blood vessel includes advancing a reverse valvulotome in a direction opposite to the natural fluid flow in the blood vessel. During advancement of the reverse valvulotome, at least one blade of the reverse valvulotome at least partially resects the valve.

[0044] The reverse valvulotomy may include at least one blade. The at least one blade may have a retracted position and an expanded position, wherein the at least one blade is substantially parallel to the longitudinal axis and the at least one blade is substantially non-parallel to the longitudinal axis in the expanded position. The at least one blade may include a sharp surface facing distally and configured to at least partially excise the valve during distal advancement of the device. The at least one blade may include a plurality of blades. The plurality of blades may include three blades. The three blades may be circumferentially spaced approximately 120 degrees apart. The method may further include expanding the blood vessel and the valve in the blood vessel. Expanding the blood vessel and the valve in the blood vessel may include applying a tourniquet to a body part containing the blood vessel. Expanding the blood vessel and the valve in the blood vessel may include expanding a balloon in the blood vessel. Expanding the blood vessel and the valve in the blood vessel may include expanding the LeMaitre device in the blood vessel.

[0045] In some embodiments, a method of achieving retrograde perfusion in a first blood vessel comprises forming a fistula between the first blood vessel and a second blood vessel and causing valve insufficiency in the first blood vessel.

[0046] The first vessel may include a vein and the second vessel may include an artery. Causing valvular regurgitation in the first vessel may include inflating a balloon across the valve to a pressure greater than about 10 atmospheres (atm) (about 1,013 kilopascals (kPa)). Causing valvular regurgitation in the first vessel may include deploying at least one stent across the valve. Causing valvular regurgitation in the first vessel may include inflating a cutting balloon. Causing valvular regurgitation in the first vessel may include atherectomy. Causing valvular regurgitation in the first vessel may include ablating the valve using ultrasound. Causing valvular regurgitation in the first vessel may include ablating the valve using laser. Causing valvular regurgitation in the first vessel may include ablating the valve using radiofrequency. Causing valvular regurgitation in the first vessel may include heating the valve. Causing valvular regurgitation in the first vessel may include at least one of advancing and retracting a catheter including a traumatic tip. Causing valvular regurgitation in the first vessel may include dilating the vessel and the valve in the vessel. Dilating a blood vessel and a valve in the blood vessel may include applying a tourniquet to a body part containing the blood vessel. Dilating a blood vessel and a valve in the blood vessel may include dilating a balloon in the blood vessel. Dilating a blood vessel and a valve in the blood vessel may include dilating a LeMaitre device in the blood vessel. Causing valvular regurgitation in a first blood vessel may include dilating a first blood vessel and a valve in the first blood vessel, advancing a guidewire through the blood vessel, and tracking the device over the guidewire. Dilating a first blood vessel and a valve in the first blood vessel may include applying a tourniquet to a body part containing the first blood vessel. Dilating a first blood vessel and a valve in the first blood vessel may include dilating a balloon in the first blood vessel. Dilating a first blood vessel and a valve in the first blood vessel may include dilating a LeMaitre device in the blood vessel. Forming a fistula between an artery and a vein may include entering the vein. Entering the vein may include inserting a needle into the vein and inserting a guidewire through the needle into the vein. The vein may be a proximal tibial vein. The method may further include advancing a catheter over a second guidewire. The guidewire may include an ultrasound receiving transducer. The method may further include advancing the guidewire in a direction of blood flow in the vein. The method may further include inserting a guide sheath into a second vein upstream of the vein. The method may further include inserting a second guide wire into the second vein. The second guide wire may include an ultrasound receiving transducer. The method may further include at least one of: snaring the guide wire with a second guide wire or a snare and snaring the second guide wire with the guide wire, and pulling the second guide wire in a direction opposite to the flow of blood into the vein. Snaring the guide wire may include injecting a contrast and using fluoroscopy visualization. The method may further include advancing a catheter over the second guide wire. The catheter may include an ultrasound receiving transducer.Forming a fistula between a first blood vessel and a second blood vessel may include inserting a launching catheter into the second blood vessel, inserting a target catheter into the first blood vessel, transmitting an ultrasonic signal from an ultrasonic transmitting transducer, rotating the launching catheter and moving the launching catheter longitudinally at least one of during and until the ultrasonic signal is received by the ultrasonic receiving transducer, and extending a needle from the launching catheter after the ultrasonic signal is received by the ultrasonic receiving transducer. The launching catheter may include an ultrasonic transmitting transducer and a needle configured to extend radially from the launching catheter. The target catheter may include an ultrasonic receiving transducer. Extending the needle may include exiting the second blood vessel, passing through interstitial tissue between the second blood vessel and the first blood vessel, and entering the first blood vessel. The ultrasonic transmitting transducer may include a directional transducer. The needle may be configured to extend radially from the launching catheter along a path aligned with the path of the directional transducer. The ultrasonic receiving transducer may include an omnidirectional transducer. Forming a fistula between the first blood vessel and the second blood vessel may include identifying a signal alignment peak on a display device. Identifying a signal alignment peak on the display device may include identifying a color indication that the signal alignment peak is greater than a threshold value. Forming a fistula between a first vessel and a second vessel may include an audible signal indication that the identification signal is aligned greater than a threshold. Forming a fistula between a first vessel and a second vessel may include inserting a launch catheter into the second vessel. The launch catheter includes a needle configured to extend radially from the launch catheter. Forming a fistula between a first vessel and a second vessel may further include inserting a target catheter containing a target device into the first vessel, expanding the target device, and extending the needle from the launch catheter. Extending the needle may include exiting the second vessel, passing through interstitial tissue between the second vessel and the first vessel, and entering the first vessel, wherein during entry into the first vessel, the needle pierces the target device. The target device may include a balloon. The balloon may include a polymer and a mesh at least partially embedded in the polymer. Expanding the target device may include inflating the balloon. The target device may include a mesh. Expanding the target device may include distally advancing a proximal portion of the mesh. Expanding the target device may include proximally retracting a distal portion of the mesh. Expanding the target device may include self-expanding the mesh. Forming a fistula between a first vessel and a second vessel may include inserting a traversing guidewire through the fistula. Forming a fistula between a first blood vessel and a second blood vessel may include enlarging the fistula. Enlarging the fistula may include inflating a balloon. Forming a fistula between a first blood vessel and a second blood vessel may include deploying a prosthesis. After deploying the prosthesis, at least a first portion of the prosthesis may be in the first blood vessel and at least a second portion of the prosthesis may be in the second blood vessel. Deploying the prosthesis may include actuating a trigger handle. The prosthesis may include a stent graft. The stent graft may include a longitudinal portion having a frustoconical longitudinal cross-section. Deploying the prosthesis may include self-expanding the prosthesis. The method may further include expanding the prosthesis using a balloon. The method may further include applying a radiopaque clip to the skin outside the skin proximal to the fistula location.The method may further include determining a distance between the first blood vessel and the second blood vessel.

[0047] In some embodiments, a fistula-forming target catheter includes a proximal portion and a distal portion. The distal portion may include an expandable member and an ultrasound receiving transducer proximal to the expandable member.

[0048] The expandable member may include a balloon. The expandable member may include a mesh. The ultrasound receiving transducer may include an omnidirectional transducer. The ultrasound receiving transducer may be radially inward from the expandable member. The catheter may further include an inflation lumen and a proximal portion in fluid communication with the expandable member. The catheter may further include a pressure sensor configured to detect puncture of the expandable member.

[0049] In some embodiments, a kit for achieving retrograde perfusion in a vein comprises a device for disabling a valve and at least one selected from a launching catheter, a targeting catheter, and a prosthesis delivery system.

[0050] The device for disabling the valve may include at least one of a reverse valvulotomy, a balloon, and a stent. The transmitting catheter may include a needle configured to extend radially from the transmitting catheter. The transmitting catheter may include an ultrasound transmitting transducer. The kit further includes a guidewire. The transmitting catheter may be configured to advance over the guidewire. The kit may further include an arterial guide sheath. The kit may further include a second guidewire. The target catheter may be configured to advance over the second guidewire. The target catheter may include an ultrasound receiving transducer. The ultrasound transmitting transducer may include an omnidirectional transducer. The target catheter may include a balloon. The kit may further include a third guidewire. The second guidewire may be configured to snare the third guidewire. The third guidewire may be configured to snare the second guidewire. The kit may further include a venous guide sheath. The kit may further include a venous entry needle. The kit may further include an entry guidewire. The kit may further include at least one balloon. The at least one balloon may be configured to pre-enlarge the fistula. The at least one balloon may be configured to expand the diameter of the blood vessel. The at least one balloon may be configured to cause valvular insufficiency. The at least one balloon may be configured to apply a pressure greater than about 10 atm (about 1,013 kPa). The kit may further include a prosthesis delivery system. The kit may further include a device configured to stretch a blood vessel. The device configured to stretch a blood vessel may include at least one of a tourniquet, a balloon, and a LeMaitre device. The kit may further include a computing device configured to be communicatively connected to at least one of the launch catheter and the target catheter. The computing device may include a laptop computer. The computing device may include a tablet computer. The computing device may include a smartphone. The computing device may include a display device configured to display information about the relative position of the launch catheter and the target catheter. The computing device may include a speaker configured to transmit information about the relative position of the launch catheter and the target catheter.

[0051] In some embodiments, a method of marking a fistula site comprises applying a marker to the skin proximal to the fistula site. The marker may be visible under fluoroscopy.

[0052] The marker may include a clip. The marker may include a radiopaque material. The fistula may be between the first blood vessel and the second blood vessel. Applying the marker may be prior to deploying the prosthesis in the fistula.

[0053] In some embodiments, a method of treating valvular insufficiency in a blood vessel includes providing a reverse valvulotome. When the reverse valvulotome is advanced in a direction opposite to the natural fluid flow in the blood vessel, at least one blade of the reverse valvulotome at least partially resects the valve.

[0054] In some embodiments, a method of achieving retrograde perfusion in a first blood vessel includes providing a first system configured to establish a fistula between the first blood vessel and a second blood vessel and providing a second device configured to cause valvular regurgitation in the first blood vessel.

[0055] In some embodiments, a method of forming a fistula in a first blood vessel includes inserting a transmitting catheter into a second blood vessel. The transmitting catheter includes an ultrasonic transmitting transducer and a needle configured to extend radially from the transmitting catheter. The method may further include inserting a target catheter including an ultrasonic receiving transducer into the first blood vessel, transmitting an ultrasonic signal from the ultrasonic transmitting transducer, and during the transmission of the ultrasonic signal and until the ultrasonic signal can be received by the ultrasonic receiving transducer, rotating the transmitting catheter and longitudinally moving at least one of the transmitting catheter. The method may further include, after the ultrasonic signal can be received by the ultrasonic receiving transducer, extending the needle from the transmitting catheter. Extending the needle may include leaving the second blood vessel, passing through the interstitial tissue between the second blood vessel and the first blood vessel, and entering the first blood vessel.

[0056] The ultrasound transmitting transducer may include a directional transducer. The needle may be configured to extend radially from the transmitting catheter along a path aligned with the path of the directional transducer. The ultrasound receiving transducer may include an omnidirectional transducer.

[0057] In some embodiments, a kit for achieving retrograde perfusion in a vein includes a launching catheter, a targeting catheter, and a prosthesis delivery system.

[0058] The transmitting catheter may include a needle configured to extend radially from the transmitting catheter. The transmitting catheter may include an ultrasound transmitting transducer. The target catheter may include an ultrasound receiving transducer. The ultrasound transmitting transducer may include an omnidirectional transducer.

[0059] The methods summarized above and set forth in further detail below describe certain actions taken by a practitioner; however, it should be understood that they may also include instructions for those actions by another party. Thus, an action such as "causing valvular insufficiency in a first blood vessel" includes "instructing the causing of valvular insufficiency in the first blood vessel."

[0060] For the purpose of summarizing the present invention and the advantages that can be achieved, some goals and advantages are described herein. Not necessarily all of these goals and advantages need to be realized according to any specific embodiment. In some embodiments, the present invention can be embodied or carried out in a manner that can achieve or optimize one advantage or a group of advantages without necessarily realizing other goals or advantages.

[0061] All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments will be apparent from the following detailed description with reference to the accompanying drawings, and the invention is not limited to any particular disclosed embodiment(s). The optional and / or preferred features described with reference to some embodiments may be combined with and incorporated into other embodiments. All references cited herein, including patents and patent applications, are incorporated by reference in their entirety. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] These and other features, aspects, and advantages of the present disclosure are described with reference to the accompanying drawings of certain embodiments, which are intended to illustrate certain embodiments and are not intended to limit the invention, wherein like reference numerals are used for like features, and wherein:

[0063] Figure 1 An example implementation of a transmitting device that directs a signal from a first body cavity to a target device in a second body cavity is schematically illustrated.

[0064] Figure 2 It is along Figure 1 Cross-sectional view along the dashed line B–B.

[0065] Figure 3 An example implementation of a transmitting device is schematically illustrated.

[0066] Figure 4 An example implementation of a target device is schematically illustrated.

[0067] Figure 5 Another example implementation of a transmitting device is schematically illustrated.

[0068] Figure 6 Example embodiments of centering devices and / or targeting devices for transmission are schematically illustrated.

[0069] Figure 7 Schematic illustration of the prosthesis in place after a procedure such as arteriovenous arterialization.

[0070] Figure 8 is a side perspective view of an example embodiment of an apparatus for providing fluid flow.

[0071] Fig. 9 show Figure 8 A device that acts as a shunt between two blood vessels.

[0072] Fig.10 is a side perspective view of another example embodiment of an apparatus for providing fluid flow.

[0073] Fig.11 is a side perspective view of yet another example embodiment of an apparatus for providing fluid flow.

[0074] Fig.12 is a side perspective view of yet another example embodiment of an apparatus for providing fluid flow.

[0075] Fig.13 is a side perspective view of yet another example embodiment of an apparatus for providing fluid flow.

[0076] Fig.14A is a schematic side cross-sectional view of an example implementation of an ultrasound transmitting catheter.

[0077] Fig. 14B It is within circle 14B Fig.14A An enlarged schematic side cross-sectional view of a distal portion of an ultrasound emitting catheter.

[0078] Fig.15A is a schematic side view of an example embodiment of an ultrasound targeting catheter.

[0079] Fig. 15B It is within circle 15B Fig.15A An enlarged schematic side cross-sectional view of an ultrasound target catheter.

[0080] Fig. 15C Is within circle 15C Fig.15A An enlarged schematic side cross-sectional view of an ultrasound target catheter.

[0081] Fig.16 is an example implementation of a diagram of detecting catheter alignment.

[0082] Fig.17 is a schematic side view of an example embodiment of a prosthesis delivery system.

[0083] Fig.18 is a schematic side view of an example embodiment of a prosthesis.

[0084] Fig.19 is a schematic side view of another example embodiment of a prosthesis.

[0085] Figures 20A-20H An example embodiment of a method of achieving retrograde perfusion is schematically illustrated.

[0086] Fig.21 is a schematic perspective view of an example embodiment of an ultrasound receive transducer.

[0087] Fig. 22 is a schematic cross-sectional view of another example embodiment of an ultrasound receive transducer.

[0088] Fig.23A is a schematic perspective view of an example embodiment of a valvulotome.

[0089] Fig. 23B is a schematic perspective view of an example embodiment of a reverse valvulotome.

[0090] Fig.24 is a schematic perspective view of an example implementation of a LeMaitre apparatus. DETAILED DESCRIPTION

[0091] Although certain embodiments and examples are described below, the invention extends beyond the specifically disclosed embodiments and / or applications and obvious variations and equivalents thereof. The scope of the invention disclosed herein should not be limited by any specific embodiment(s) described below.

[0092] Minimally invasive surgery can provide the means for treating a wider range of patients, including those patients currently excluded from standard surgical techniques. One such process is percutaneous in situ coronary venous arterialization (PICVA), which is a catheter-based coronary artery bypass process, in which the occlusion in the diseased artery is "bypassed" by setting up access between the coronary artery and the adjacent coronary vein. In this way, arterial blood is diverted to the venous system and can perfuse cardiac tissue and restore blood supply to ischemic tissue in a retrograde manner (retrograde perfusion). Execution of some example devices and methods of processes such as PICVA is described in PCT Publication No. WO 99 / 049793 and U.S. Patent Publication No. 2004 / 0133225, which are incorporated by reference in their entirety at this point.

[0093] Successfully executing the minimally invasive process that makes blood flow turn to adjacent vein from coronary artery has low success rate so far, and is often due to not being able to properly target vein from artery.Without suitable system and method, these processes (for example, attempt to target vein by the combination of X-ray fluorescence inspection and imaging ultrasound probe positioned on catheter distal tip, such as described in U.S. Patent Publication No. 2004 / 0133225) are often doomed to failure even before starting.In fact, such arrangement may be difficult to guide (navigate), and the positioning of adjacent vein may require considerable skill with respect to clinician.In general, the improvement of the system and method for targeting, such as using those of catheter described herein, can make it possible to realize process such as PICVA and transvascular surgery.Without this improvement, such percutaneous technique is still secondary compared with traditional open heart surgery and other types of bypass surgery.

[0094] The present application, according to several embodiments, describes methods and systems that can be used during minimally invasive surgery that can reduce the performance of traditional surgery to treat diseases such as coronary heart disease and critical limb ischemia. For example, patients who may otherwise not be able to undergo surgery such as coronary artery bypass surgery or peripheral artery bypass surgery can be treated, and the amount of surgical trauma, infection risk, and / or recovery time can be reduced or significantly reduced compared to traditional surgery.

[0095] Figure 1 An example embodiment of a transmitting device 10 for directing a signal from a first body cavity 30 to a target device 20 in a second body cavity 35 is schematically illustrated. The transmitting device 10 includes a signal transmitter 12. The transmitting device 10 may include, for example, a catheter including an elongated flexible shaft portion and a tip portion, and may provide a conduit for administering treatment within a patient's body. The transmitting device 10 may be suitable for positioning and moving through a first cavity or vessel 30 (e.g., a ventricle, a coronary artery, a coronary vein, a peripheral artery, a peripheral vein) within a patient's body. The elongated portion of the transmitting device 10 includes an outer sheath 11 enclosing a space, which defines a cavity 13. The space within the cavity 13 may be appropriately divided or subdivided as desired to define pathways for administering treatment, controlling the positioning of the transmitting device 10, etc. Such subdivision may be achieved, for example, longitudinally or concentrically in an axial manner.

[0096] The transmitting device 10 includes a signal transducer 12. The signal transducer 12 is configured to provide or transmit a signal 40 directed outwardly from the transmitting device 10. Figure 1, the signal 40 is directed radially outward from the transmitting device 10 in a direction perpendicular to the longitudinal axis of the transmitting device 10. As mentioned in more detail below, in some embodiments, the direction of the signal 40 need not be perpendicular to the longitudinal axis of the transmitting device 10 and may be directed at an angle to the longitudinal axis of the transmitting device 10. The signal transducer 12 may thus constitute at least a part of the signal generating means.

[0097] The signal transducer 12 is connected to a signal transmitter 50. The signal transmitter 50 may be suitably selected from ultrasound or a suitable electromagnetic source such as laser, microwave radiation, radio waves, etc. In some embodiments, as described in further detail below, the signal transmitter 50 is configured to generate an ultrasound signal, which is forwarded to the signal transducer 12, which in turn directs the signal 40 out of the first body cavity 30 into the surrounding tissue.

[0098] The target device 20 is located in an adjacent second body cavity or blood vessel 32 (e.g., a ventricle, a coronary artery, a coronary vein, a peripheral artery, a peripheral vein) in the patient's body. The first and second body cavities 30, 32 are separated by intervening tissue 34, which is sometimes referred to as interstitial tissue or a septum. The first and second body cavities 30, 32 are adjacent to each other in a parallel manner for at least a portion of their respective lengths. For example, it is known that many veins and arteries of the body run parallel to each other for at least a portion of their total lengths.

[0099] The target device 20 may adopt an arrangement similar to that of the generating device 10. For example, the target device 20 may include a catheter including an elongated flexible rod-shaped portion and a tip portion. For another example, fine movement and positioning of the target device 20 within the body cavity 32 may be achieved. For yet another example, the target device 20 may include an outer sheath 21 enclosing a space defining a cavity 23. The cavity 23 may be appropriately divided, for example, as with the transmitting device 10.

[0100] The target device 20 includes a receiving transducer 22 configured to receive a signal 40 from the transducer 12 of the transmitting device 10. The receiving transducer 22 constitutes at least a part of the signal detection means. In use, when the receiving transducer 22 receives the signal 40 transmitted from the signal transducer 12, the receiving transducer 22 transmits the received signal to the signal detector 60. The signal detector 60 is configured to provide an output reading to a user of the system, for example via an output display 61. The output display 61 may be a visual display, an audio display (e.g., beeps or emits some other sound upon receiving a signal), etc.

[0101] In this manner, the transmission and detection of directed signal 40 may allow for the guidance and positioning of transmitter device 10 relative to target device 20. In use, transmitter device 10 and target device 20 may be manipulated by a user of the system until output display 61 indicates that signal 40 is being received by target device 40.

[0102] In some embodiments, the signal 40 includes an ultrasonic signal or is an ultrasonic signal. The signal 40 is directional and is transmitted by the signal transducer 12 in the shape of a narrow cone or arc (e.g., the width of the signal band increases as the distance from the signal transducer 12 increases). Therefore, the alignment accuracy between the transmitting device 10 and the target device 20 depends not only on the signal detection, but also on the distance between the two devices-because the signal beam width is larger at a greater distance. This level of error is called "position uncertainty". There may be a certain level of tolerance for position uncertainty; however, if the treatment is accurately guided, the amount of uncertainty should be reduced or minimized. 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 (e.g., the error amplitude on either side of the center line) is 1 mm at a 5 mm vertical spacing between the transmitting device 10 and the target device 20. For clinical applications, the position uncertainty should generally not exceed about ±5 mm (for a total signal beam width of 10 mm at the receiving point). In some embodiments, the position uncertainty is between about ±0.01 mm and about ±4.50 mm or between about ±0.1 mm and about ±2 mm. In some embodiments, the position uncertainty does not exceed about ±1 mm.

[0103] The strength of the signal 40 can be a factor in the detection, and the signal strength generally decreases as the distance between the transmitting device 10 and the target device 20 increases. The distance is determined in part by the amount of intervening tissue 34 between the devices 10, 20. For example, if the signal 40 is an ultrasound signal, a significant decay of the signal can be expected when the transmitting device 10 and the target device 20 are separated by more than about 20 mm of solid tissue (e.g., intervening tissue 34). The density of the intervening tissue 34 can also have an effect on the decay of the signal 40 relative to the distance (e.g., dense tissue decays the signal more than less dense tissue).

[0104] The frequency of the ultrasonic signal may also affect the thickness of the signal transducer, which is 0.075 mm at 30 MHz for a standard ultrasonic ceramic transducer (eg, piezoelectric transducer (PZT)).

[0105] Figure 2 It is along Figure 14. A cross-sectional view of a device 10 and a target device 20 is shown in FIG. 4. The correct orientation of the transmitting device relative to the target device can be a factor in the detection because the orientation line 41 can determine where the treatment will be applied. If the directional signal 40 is associated with the device used to deliver the treatment (e.g., parallel and longitudinally offset), the clinical need for precise placement of the treatment in the patient can be better utilized. For example, in this way, a user of the system can apply the treatment to the correct location by ensuring that the transmitting device 10 and the target device 20 are correctly positioned via the transmission and reception of the signal 40. Figure 2 The neutral orientation line 41 indicates not only the direction of signal travel but also the path along which therapy can be administered to the patient.

[0106] Figure 3 Schematically illustrates an example embodiment of a transmitting device 10. The transmitting device 10 includes a signal transducer 120 oriented at an oblique angle relative to the longitudinal axis of the transmitting device 10. When the transmitting device enters the body cavity 30, the signal 40 is transmitted at an angle (eg, forward travel, lateral travel) to the direction of travel of the transmitting device 10. Figure 1 and 2 ). In some embodiments, the beam angle is approximately perpendicular to the longitudinal axis of the transmitting device 10. In some embodiments, when 0° corresponds to the longitudinal axis of the transmitting device 10 in the direction of travel, the beam angle is between about 20° and about 60° from the vertical, between about 30° and about 50° from the vertical, or about 45° from the vertical.

[0107] The launch device 10 includes a hollow needle or cannula 17, which is an example device for administering treatment. During the travel of the launch device 10, the hollow needle 17 is located in the cavity 13 of the launch device 10 in an undeployed or retracted state. The hollow needle 17 can be deployed / extended from the launch device 10 via the hole 16 in the outer sheath 11 at a time deemed appropriate by the user (e.g., after the signal 40 is detected by the target device 20). The hole 16 can allow fluid communication between the cavity 13 and the body cavity 30 ( Figure 1 ).like Figure 3 As illustrated in the example embodiment of FIG. 4 , the hollow needle 17 can travel along a path parallel to the direction of the signal 40. The hollow needle 17 can be used to pierce the intervening tissue 34 ( Figure 1 In some embodiments, the hollow needle 17 is transported integrally through the intervening tissue 34 and in doing so allows the launch device 10 to enter the second body cavity 32 ( Figure 2 If desired, the path created by the hollow needle 17 through the intervening tissue 34 can subsequently be widened to allow fluid communication between the first body lumen 30 and the second body lumen 32.

[0108] Treatment devices suitable for use in several embodiments may include, for example, devices and / or instruments selected from the group consisting of cannulas, lasers, radiation emitting devices, probes, drills, blades, wires, needles, suitable combinations thereof, and the like.

[0109] In some embodiments, the hollow needle 17 includes a sensor 19 that can help further determine the position information of the tip of the hollow needle 17 relative to the launch device 10. In some embodiments, the sensor 19 is configured to detect changes in the static pressure of the fluid. Other sensors suitable for use in the systems and methods described herein may include temperature sensors, oxygenation sensors, and / or color sensors.

[0110] Optionally, the hollow needle 17 may include an additional signal transducer 122. Figure 3 In the embodiment shown in , the signal transducer 122 is located near the tip of the hollow needle 17 on the end of the guide wire 14. If desired, the signal transducer 122 can also or alternatively be located on the hollow needle 17. In use, the signal transducer 122 is driven with a short transmit pulse that produces a directional signal and a non-directional signal pulse. The signal pulse can be detected by a receiving transducer 22 mounted on the target device 20. The distance from the guide wire 14 or the hollow needle 17 to the receiving transducer 22 and therefore to the target device 20 can be determined at least in part by the time 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.

[0111] Figure 4 An example implementation of a target device 20 is schematically illustrated. Figure 4 In the embodiment shown in , the target device 20 is located in the body cavity 32. As mentioned above, the target device 20 includes a receiving transducer 22 for receiving the signal 40. The receiving transducer 22 can be unidirectional (e.g., only capable of receiving or configured to receive signals from one direction) or omnidirectional (e.g., capable of receiving or configured to receive signals from any direction). Arrow A shows the reverse direction of blood flow after arteriovenous arterialization (also known as PICVA) has been achieved. The target device 20 includes an omnidirectional ultrasonic signal receiving transducer 60. An optional reflection cone 601 can guide the signal 40 to the disc-shaped receiving transducer 60. The acoustic window 602 can separate the reflection cone 601 from the receiving transducer 60. In some embodiments, the omnidirectional ultrasonic signal receiving transducer can be obtained by positioning a cylinder of a flexible piezoelectric material such as polyvinylidene fluoride (PVDF) around the outer sheath of the target device 20. In this way, the cylinder can function in a similar or equivalent manner to the receiving transducer 60.

[0112] exist Figure 4In the embodiment illustrated in the figure, the target device 20 includes an optional passage 25 for administering a medicament such as a therapeutic agent to a patient. In some embodiments, the passage 25 acts as a conduit to allow the application of a blocking material 251 for at least partially blocking or occluding the body cavity 32. The blocking material 251 can be appropriately selected from a gel-based substance. The blocking material 251 can also or alternatively include an embolization member (e.g., a balloon, a self-expanding stent, etc.). The placement of the blocking material 251 can be guided by moving the target device 20. The presence of a guide member 24 in the cavity 23 of the target device 20 allows the user to precisely manipulate the position of the target device 20 as needed.

[0113] Refer again Figure 2 , the transmitting device 10 includes a signal transducer 12 that can optionally be oriented so that the signal 40 is transmitted at an angle that is non-perpendicular to the signal transducer 12. Figure 5 Schematically illustrates another example embodiment of the transmitting device 10. In some embodiments, for example, Figure 5 In the transmitter device 10 shown in FIG. 1 , the signal transducer is in the form of a signal transducer array 123. The signal transducer array 123 includes a plurality of signal transducer elements 124 that may be collectively oriented to at least partially define a signal beam width and angle relative to the transmitter device 10. The small size of the elements 124 may allow the signal transducer 123 to not occupy a significant proportion of the cavity 13 of the transmitter device 10.

[0114] Figure 5 The embodiment shown in can be used for ultrasound beamforming signals. Figure 5 An array of signal transducer elements 124 are shown connected to the transmitter 50 via delay elements 51, which delay the signals to each element 124 relative to each other. The delay elements can provide or ensure that the ultrasound wave front from each element 124 is aligned to produce a beam of ultrasound 40 at a desired angle. For example, in some embodiments where the signal 40 includes visible light, an array of LEDs can also or alternatively be used.

[0115] Figure 6 Schematically illustrates example embodiments of centering devices and / or targeting devices 10, 20 for launch. To aid in the alignment process between a launch device 10 in a first body cavity 30 and a targeting device 20 in a second body cavity 32, one or both of the devices 10, 20 may include means for centering the respective device within their body cavities.

[0116] In some embodiments, the centering device includes an inflatable sac or balloon 111 that is located in the cavity 13, 23 when not deployed and can be inflated when the device 10, 20 reaches the desired position in the patient. The balloon 111 can be arranged on the outer surface of the outer sheath 11, 21. The balloon 111 is annular in shape so that it at least partially surrounds the device 10, 20 in a toroidal or doughnut-like manner. The balloon 111 can be arranged so that it is inflated on only one side or only two opposite sides of the device 10, 20. Figure 6 As illustrated in , the balloon 111 is deployed on one side of the launching device 10 .

[0117] In some embodiments, the centering device includes one or more ring structures 112 in an unexpanded or retracted state located in the cavity 13, 23 or in a recess made in the outer sheath 11, 21. When the device 10, 20 reaches the desired position in the patient, the one or more ring structures 112 can expand radially outward from the device 10, 20, thereby centering the device 10, 20 in the body cavity 30, 32. The outward expansion of the ring structure 112 can be appropriately achieved by compressing the length of the wire, for example, so that it is bent outward from the outer sheath 11, 21 into an arc shape. A centering device using this structure may include multiple compressible lengths of wire or other suitable flexible materials arranged in parallel with radial spacing around the edge of the outer sheath 11, 21. Compression of the multiple wires can be caused via sliding members (not shown) located proximally and / or distally near the ends of the multiple wires. The sliding member is capable of translational movement along the longitudinal axis of the device 10, 20. As Figure 6 As illustrated in FIG. 1 , the targeting device 20 includes a fully deployed centering device 112 that centers the targeting device 20 within the body cavity 32 .

[0118] Other possible means of centering the device 10, 20 within the body lumen 30, 32 include, but are not limited to, an expandable Chinese lantern device, a reversibly expandable stent, a coil, a helix, a retractable stylet or leg, combinations thereof, and the like.

[0119] In some embodiments, a centering device or other device (e.g., a balloon, a metal stand-off with different lengths, etc.) can be used to orient the device 10, 20 within the body cavity 30, 32 rather than in the center of the body cavity or substantially in the center of the body cavity. For example, the device 10 can be oriented close to the wall of the body cavity 30 where the needle 17 will exit the body cavity 30, which can, for example, provide a shorter ultrasound signal path and / or reduce errors due to the needle 17 passing through the space within the lumen. For another example, the device 10 can be oriented close to the wall of the body cavity 30 opposite the wall of the body cavity 30 where the needle 17 will exit the body cavity 30, which can, for example, provide a solid surface for the needle 17 to push against. For yet another example, the device 20 can be oriented close to the wall of the body cavity 32 where the needle 17 will enter the body cavity 32, which can, for example, provide a shorter ultrasound signal path. Other device orientations that are not centered nor close to the vessel wall are possible (eg, some fraction of the diameter away from the wall and / or center of the lumen, such as 1 / 2, 1 / 3, 1 / 4, etc.).

[0120] Example

[0121] The methods and systems described herein show particular application in cardiovascular surgery according to several embodiments. Certain aspects are further illustrated by the following non-limiting example, in which the system is used by a clinician to perform a PICVA procedure, thereby enabling retrograde perfusion of cardiac tissue after occlusion of a coronary artery.

[0122] The launch device 10 is inserted into the occluded coronary artery by standard keyhole surgical techniques (e.g., advanced over a guidewire, advanced through a guide catheter). The target catheter 20 is inserted into the coronary vein running parallel to the coronary artery by standard keyhole surgical techniques (e.g., advanced over a guidewire, advanced through a guide catheter). The coronary vein is not occluded and, therefore, provides an alternative pathway for blood flow to the myocardium, which effectively bypasses the occlusion in the coronary artery.

[0123] The transmitting catheter 10 includes a directional PZT ultrasonic transducer 12 (e.g., available from CTS Piezoelectric Products of Albuquerque, New Mexico) so that the directional ultrasonic beam in this embodiment is sent at a 45° angle (relative to the longitudinal axis of the transmitting device), preferably in the direction of blood flow in the artery 30, but other angles including about 90° are also possible. The ultrasonic transducer 12 is activated, and a 30 MHz directional ultrasonic signal 40 is sent from the transmitting catheter 10 in this embodiment, but other frequencies are also possible. The target catheter 20 includes an omnidirectional ultrasonic receiving transducer 60. To help locate both the transmitting catheter 10 and the target catheter 20, both catheters 10, 20 include a centering or orientation device, in this embodiment, in the form of a ring-shaped expandable balloon 111, but other centering or orientation devices or their absence are also possible. When the transmitting catheter 10 is considered to be in a suitable position near the occlusion site in the coronary artery 30, the centering device 111 on the transmitting catheter 10 is deployed by the clinician. This can be determined via standard fluoroscopic imaging techniques and / or based on physical resistance. The target catheter 20 is then moved within the adjacent coronary vein 32 until the guided ultrasound signal 40 is detected by the signal receiving transducer 60. To allow for more precise alignment between the transmitting catheter 10 and the target catheter 20, the centering device 111 on the target catheter 20 can be deployed before or after the signal 40 is detected.

[0124] After receiving the transmitted signal 40, the clinician can determine that both the transmitting catheter 10 and the target catheter 20 are properly positioned rotationally and longitudinally within their respective blood vessels 30, 32 to allow the arterial-venous connection process to begin. The target catheter 20 can be used to occlude blood flow within the coronary vein 32 via the application of the gel occluding material 251 through the passage 25 in the target catheter 20. The occluding material 251 can be applied at a downstream location in the coronary vein 32 according to the venous blood flow relative to the location of the receiving signal transducer 60.

[0125] The clinician can then initiate a venous-arterial connection by deploying the hollow needle 17 from the launch catheter 10 substantially along such a path, which is parallel to and close to 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 pass through a path that intersects the ultrasound signal path at a point within the coronary vein 32. The hollow needle 17 optionally includes a sensor 19 near its tip that 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 when the hollow needle 17 passes between the two blood vessels 30, 32. Optionally, the hollow needle 17 includes a guide wire 14 in the hole or cavity of the hollow needle 17 during deployment. Once the hollow needle 17 and the guide wire 14 pass through the intervening tissue 34, the hollow needle 17 can be retracted into the cavity 13 of the launch catheter 10, leaving the guide wire 14 in place. In some embodiments, once the hollow needle 17 has passed through the intervening tissue 34 , the user may separately pass the guidewire 14 through the hole or lumen of the hollow needle 17 and then retract the needle 17 into the launching catheter 10 .

[0126] The clinician withdraws the launch catheter 10 from the patient, leaving the guidewire 14 in place. A further catheter device is then slid over the guidewire 14. Figure 7 Schematically illustrates a prosthesis 26 such as an expandable stent 26 in place after a process such as arterial-venous arterialization. Further details about possible prostheses including stents and stent-grafts are provided below. The stent 26 can be deployed to widen the perforation in the intervening tissue 34 between the coronary artery 30 and the coronary vein 32, wherein the intermittent arrow A represents the blood flow direction of the stent 26 between the first and second body cavities 30, 32 (e.g., arterial blood is thus turned to the venous system and can make retrograde perfusion of myocardial tissue). The stent 26 can block the upward flow in the cavity 32, forcing the blood flow in the cavity 32 to be in the same direction as the blood flow in the cavity 30. The graft material of the stent 26 can form a liquid-tight cavity between the cavity 30 and the cavity 32. The target catheter 20 is withdrawn from the patient, leaving the blocking material 251 in place. Optionally, further blocking or suturing can be inserted into the coronary vein to inhibit or prevent the reversal of arterial blood flow, as described in further detail herein.

[0127] Although the specific examples described above are about cardiovascular surgery, the methods and systems described herein can have far-reaching applications in other forms of surgery. For example, any surgery involving the need to guide treatment from one body cavity (e.g., for the treatment of peripheral arterial disease) toward another adjacent body cavity can be considered. Therefore, applications in the fields of neurosurgery, urology, and general vascular surgery are also possible. This type of treatment is not limited to forming pathways between body cavities. For example, the methods and systems described herein can also be used in guiding techniques such as catheter ablation, non-contact mapping of the ventricles, delivering drugs to precise areas of the body, etc.

[0128] Certain techniques for effectively bypassing occlusions in arteries by percutaneous surgery are described above. These techniques include establishing a passage or channel between a first channel and a second channel near the first channel to interconnect the first channel and the second channel through a third channel, wherein the first channel is such as an artery, vein or ventricle upstream of the occlusion, and the second channel is such as an artery, vein or ventricle. Fluids such as blood can be diverted from the first channel to the second channel via the interconnected third channel. In embodiments where the first channel includes an artery and the second channel includes a vein, arterial blood can be perfused into the tissue in a retrograde manner (retrograde perfusion).

[0129] As described above, an interconnecting channel between a first body passage and a second body passage can be established by, for example, deploying a needle outwardly from a first catheter located within the first passage so that the needle passes through the interstitial tissue or septum between the first passage and the second passage. A second catheter can be located in the second passage, thereby providing a target device that receives a signal, such as an ultrasound signal, sent from the first catheter. By monitoring the received signal, the position of the first catheter relative to the second catheter can be determined, thereby ensuring that the needle is deployed in the correct position and orientation to establish a channel for fluid flow between the first passage and the second passage.

[0130] In order to provide or maintain blood flow through the interconnected channels or pathways, a structure containing a cavity can be inserted into the channel to support interstitial tissue and / or to inhibit or prevent channel closure. For example, as described herein, the tube can include a stent that expands or self-expands in the pathway using a balloon catheter. A catheter that delivers the structure, such as a balloon catheter or a catheter that allows self-expansion, can be guided to the pathway by a guidewire deployed in the channel by a first catheter.

[0131] As the heart beats, channels such as arteries, veins, and ventricles can pulsate, for example, due to movement of the heart wall, peripheral limbs, and / or fluctuations in pressure within the channels themselves. This pulsation can cause the channels to move relative to each other, which can impose stresses on structures within the interconnected channels therebetween. Such stresses can be greater than the stresses experienced by structures within a single channel. Stress can lead to premature failure of the structure, for example, through fatigue failure of stent struts. Failure of the structure can result in damage to interstitial tissue and / or occlusion of the interconnected channels, which can result in significant complications or complete failure of treatment.

[0132] Figure 8 A device or implant or prosthesis 100 for providing or maintaining fluid flow through at least one passageway is illustrated. The device 100 includes a first or proximal portion 102, a second or distal portion 104, and an intermediate portion 106 between the proximal portion 102 and the distal portion 104. The device includes a hole or cavity 110 for passage of fluid through the device 100. The device 100, such as at least the intermediate portion 106 of the device 100, includes a flexible polymer tube 108. The flexible polymer tube 108 can at least partially define the cavity 110.

[0133] The device 100 includes a support structure (e.g., at least one stent) including a mesh 112 and a mesh 114. In some embodiments, at least a portion of the mesh 112 is embedded in the outer wall of the tube 108 near the proximal portion 102 of the device 100. In some embodiments, at least a portion of the mesh 114, such as wires or struts, is embedded in the outer wall of the tube 108 near the distal portion 104 of the device 110. The meshes 112, 114 may include a biocompatible metal such as stainless steel and / or a shape memory material such as nitinol or chrome cobalt.

[0134] Wire meshes 112, 114 may stiffen ends 102, 104, respectively. In some embodiments where middle portion 106 does not include a mesh, middle portion 106 may be relatively flexible compared to ends 102, 104, and / or ends 102, 104 may have relatively high radial stiffness.

[0135] In some embodiments, the ends 102, 104 of the device 100 are expandable in diameter. For example, the wire mesh 112, 114 may have a smaller diameter than the passageway, such as a blood vessel, in which the device 100 is to be deployed after being formed or manufactured. When the device 100 is in a suitable position in the passageway, the ends 102, 104 may expand or deform outwardly so that the respective diameters of the ends 102, 104 increase, such as to abut against the inner sidewall of the passageway. The ends 102, 104 are configured to maintain the expanded diameter indefinitely, such as by plastic deformation of the material (e.g., wires, struts) of the mesh 112, 114 and / or by providing a locking mechanism arranged to mechanically lock the mesh 112, 114 in the expanded position. The middle portion 106 of the device 100 may be expandable in diameter, such as via plastic deformation of the tube 108.

[0136] Fig. 9 show Figure 8 The device 100 is expanded to provide a fluid flow path between a first channel 116 and a second channel 118. The channels 116, 118 may include coronary vessels, such as coronary arteries 116 and coronary veins 118, or vice versa. The channels 116, 118 may include peripheral blood vessels (e.g., blood vessels in the limbs), such as femoral arteries or other peripheral arteries 116 and femoral veins or other peripheral veins 118, or vice versa. The ends 102, 104 and the middle portion 106 of the device 100 have been expanded to contact and push against the inner walls of the channels 116, 118. The distal portion 104 of the device 100 is located in the second channel 118, and the proximal portion 102 of the device 100 is located in the first channel 116. The middle portion 106 extends through an opening or interconnecting channel 130 surgically formed between the channels 116, 118.

[0137] The flared ends 102, 104 of the device 100 are resilient and impart an outward radial force to the inner walls of the passages 116, 118. Due to the radial rigidity of the ends 102, 104 of the device 100, the ends 102, 104 are held or secured in position within the respective passages 116, 118. Sliding of the device 100 within the passages 116, 118 is thus prevented or reduced. In this manner, the ends 102, 104 of the device 100 can secure or hold the device 100 in position, in use, while providing or maintaining fluid flow ( Figure 8 ). In this way, the device 100 can act as a shunt between the first channel 116 and the second channel 118.

[0138] The middle portion 106 of the device 100 may be flexible, for example, allowing the middle portion 106 to form an 'S' shape (eg, a shape formed by the combination of the first channel 116, the second channel 118, and the interconnecting channel 130) Fig. 9 In response to relative movement of the channels 116 , 118 , the flexible middle portion 106 can cause the ends 102 , 104 of the device 100 to move relative to each other.

[0139] In embodiments where the intermediate portion 106 does not include a wire mesh but instead includes a tube 108 of a flexible polymer material, the intermediate portion 106 may be less susceptible to damage due to mesh fatigue, such as from cyclic or other stresses imparted by relative movement through the channels 116 , 118 .

[0140] The middle portion 106 of the device 100 has sufficient elasticity to maintain the expansion of the interconnecting channel 130 so that the interconnecting channel 130 remains open to provide or maintain a blood flow path from the artery 116 to the vein 118 via the lumen 110 of the tube 108 ( Figure 8 ). Blood flow from artery 116 to vein 118 via interconnecting channel 130 can thus be provided or maintained through lumen 110 of tube 108. Device 100 at least partially supports artery 116, vein 118, and interconnecting channel 130 to provide a path for fluid communication through device 100.

[0141] The proximal portion 102 and the distal portion 104 of the device 100 are arranged so that, when the device 100 is deployed with the distal portion 104 in the vein 118 and the proximal portion 102 in the artery 116, for example Fig. 9 , the diameter of the expanded distal portion 104 is sufficient to maintain the distal portion 104 within the vein 118, and the diameter of the expanded proximal portion 102 is sufficient to maintain the proximal portion 102 within the artery 116. The diameter of the proximal portion 102 can therefore be different than the diameter of the distal portion 104. By selecting appropriate diameters for the end portions 102, 104 and the middle portion 106, the device 100 can be customized for certain anatomies and / or the anatomies of individual patients.

[0142] We will now describe the Figure 8 The device 100 is used to provide a shunt between an occluded artery 116 and vein 118 (eg, a coronary artery 116 and a coronary vein 118, or a peripheral artery 116 and a peripheral vein 118) to achieve retrograde perfusion of arterial blood, such as Fig. 9 As shown in .

[0143] The catheter can be inserted into the patient's arterial system via a small hole usually cut in the patient's groin area. The catheter is supplied to the artery 116 and directed to a position upstream of the occlusion site, such as at a site close to and parallel to or substantially parallel to the vein 118. The hollow needle is deployed from the catheter, through the wall of the artery 116, through the interstitial tissue 132 that separates the artery 116 and the vein 118, and through the wall of the vein 118. The path of the needle establishes an interconnected channel or opening 130, which allows blood to flow between the artery 116 and the vein 118. The deployment of the needle can be guided by a transmitter (e.g., a directional ultrasound transmitter) connected to the catheter in the artery 116 and a receiver (e.g., an omnidirectional ultrasound receiver) connected to the catheter in the vein 118, or vice versa, such as described herein and in U.S. Patent Application No. 11 / 662,128. Other methods of forming the opening 130 are also possible (e.g., with or without directional ultrasound guidance, with other types of guidance such as described herein, from vein to artery, etc.).

[0144] Before the needle is withdrawn from channel 130, a guide wire (e.g., Figure 3 A guide wire 14 (described above) is inserted through the hollow needle and into the vein 118. The needle is then retracted, leaving the guide wire in place in 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 guide wire can be used to guide a further catheter to the interconnecting passage 130 between the artery 116 and the vein 118.

[0145] The catheter carrying the device 100 in a non-expanded state is advanced toward the interconnecting channel 130, guided by a guidewire, such as by a rapid exchange lumen or through the lumen 110. For example, the catheter may include a balloon catheter configured to expand at least a portion of the device 100 and / or a catheter configured to allow at least a portion of the device 100 to self-expand. The distal portion 104 of the device 100 passes through the interconnecting channel 130 and enters the vein 118, leaving the proximal portion 102 in the artery 116. The middle portion 106 of the device 100 is at least partially in the channel 130 and at least partially within the artery 116 and the vein 118. The middle portion 106 is curved to adopt a curved or "S" shaped configuration, depending on the anatomical structure of the site. Adopting such a curvature can make the shape of the middle portion 106 extending through the interconnecting channel 130, and optionally entering at least one of the channels 116, 118, consistent with the shape of at least the interconnecting channel 130.

[0146] For example, the distal portion 104 of the device 100 expands after balloon inflation or by self-expansion, thereby increasing the diameter of the distal portion 104 and fixing the distal 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, such as by inflation of the balloon, so that the interconnecting channels 130 can be widened or enlarged to obtain blood flow (e.g., adequate blood flow) from the artery 116 to the vein 118. For example, the proximal portion 102 of the device 100 expands after balloon inflation or by self-expansion, thereby increasing the diameter of the proximal portion 102 and fixing the proximal portion 102 against the inner wall of the artery 116.

[0147] After the ends 102, 104 of the device 100 are expanded, for example due to self-expansion and / or balloon expansion, and with or without improved expansion after deployment, the catheter and guidewire are withdrawn from the patient's body. In this manner, the device 100 is secured or mounted in place within the vein 118, artery 116, and interconnecting passage 130, such as Fig. 9 In embodiments where the device 100 comprises a stent graft, the graft, which can form a fluid-tight passage between the artery 116 and the vein 118, can inhibit or prevent antegrade flow of blood in the vein 118 because such passage is blocked, which can exclude or displace the occluding agent in the vein 118.

[0148] The catheter can be adapted to selectively expand the proximal portion 102, the distal portion 104, and / or the middle portion 106 of the device 100, either individually or in combination, such as by providing two or more separately inflatable balloons or balloon portions, a single balloon configured to simultaneously expand all portions of the device 100, or a single balloon configured to expand one or more selected portions of the device 100. For example, the ends 102, 104 can be self-expanding, and the middle portion 106 can be expanded by the balloons enlarging the passage 130. In some embodiments including balloon expansion, all or selected portions of the device 100 can be expanded simultaneously, such as by a balloon passing through the entire length of the device 100 or by multiple balloons spaced longitudinally to selectively expand selected portions of the device 100, and / or by a balloon or multiple balloons expanding sequentially. In some embodiments including at least partial self-expansion, all or selected portions of the device 100 can be expanded, such as by proximal retraction of a sheath on or around the device 100, which can cause the device 100 to deploy from distal to proximal as the sheath is proximally retracted. It is also possible that the device 100 is deployed proximally to distally and that the device 100 is deployed first midway and then at both ends. In some embodiments, such as in embodiments where the device 100 is at least partially conical or tapered, a conical or tapered balloon can be used to at least partially expand the device 100. In some such embodiments, the portion of the balloon proximal to the vein 118 can have a larger diameter than the portion of the balloon proximal to the artery 116, such as to allow the device 100 to adapt to a changing vein diameter due to any increase in pressure or blood flow in the vein 118.

[0149] Other steps may be included in the process. For example, before the device 100 is deployed, a balloon catheter may be directed to the interconnecting channel 130 and positioned so that the expandable balloon portion of the catheter is located in the interconnecting channel 130. After the balloon is expanded, the balloon pushes against the walls of the interconnecting channel 130 to widen or expand the interconnecting channel 130 to facilitate subsequent insertion of the device 100.

[0150] Fig.10 Another device 134 for providing fluid flow through at least one channel is illustrated. Device 134 includes a mesh 136 and a polymer tube 108. Mesh 136 is shown as being outside of polymer tube 108, but as described herein, it may also or alternatively be on the inside of the polymer tube and / or within the polymer tube 108. As described with respect to device 100, device 134 includes a proximal portion 102, a distal portion 104, and a middle portion 106. Fig.10 In the illustrated embodiment, the mesh 136 extends along the entire length of the device 134 , including along the intermediate portion 106 .

[0151] In some embodiments, the spacing of the filaments or struts of the mesh 136 varies along the length of the device 134. For example, the winding density of a woven or layered filamentary mesh can be varied and / or the window size pattern of a cut mesh can be varied.

[0152] In some embodiments, the spacing can be relatively small in the proximal portion 102 and the distal portion 104, and the spacing can be relatively large in the middle portion 106. In other words, the density and window size of the mesh 136 can be relatively low in the middle portion 106, and the density and window size of the mesh 136 can be relatively high in the ends 102, 104. In some such embodiments, the middle portion 106 can be flexible compared to the ends 102, 104. The relatively rigid ends 102, 104 can be joined and fixed in the channel. Although the mesh 136 in the middle portion 106 can withstand stresses such as cyclic stresses, in use, the relatively high flexibility of the middle portion 106 due to the low density or window size makes the effects of stresses lower, because the middle portion can bend in response to stresses. The risk of fatigue failure of the device 134 and specifically the filaments or struts 138 of the mesh 136 can therefore be reduced compared to a device having uniform flexibility along its entire length.

[0153] In some embodiments, the spacing can be relatively large in the proximal portion 102 and the distal portion 104, and the spacing can be relatively small in the middle portion 106. In other words, the density of the mesh 136 can be relatively high in the middle portion 106 (or the window size of the mesh 136 can be relatively small), and the density of the mesh 136 can be relatively low in the ends 102, 104 (or the window size of the mesh 136 can be relatively large). In some such embodiments, the middle portion 106 can have a radial strength sufficient to inhibit or prevent the channel 130 from collapsing, yet still be flexible enough to bend in response to stresses such as cyclic stress. The ends 102, 104 can be joined and fixed in the channel.

[0154] Fig.11Another device or implant or prosthesis 140 that provides fluid flow through at least one channel is illustrated. As described with respect to device 100, device 140 includes a proximal portion 102, a distal portion 104, and a middle portion 106. Device 140 includes a polymer tube 108 and a support structure including a first mesh 142 and a second mesh 144. The first mesh 142 extends from the proximal portion 102 toward (e.g., into) the middle portion 106, and optionally into the distal portion 104. The second mesh 144 extends from the distal portion 104 toward (e.g., into) the middle portion 106, and optionally into the proximal portion 102. The meshes 142, 144 thus overlap each other at least at the middle portion 106. Both meshes 142, 144 may be on the outside of tube 108, on the inside of tube 108, or embedded within tube 108, or one mesh may be on the outside of tube 108, on the inside of tube 108, or embedded within tube 108 while the other mesh is variously on the outside of tube 108, on the inside of tube 108, or embedded within tube 108 (e.g., one mesh is inside tube 108 and one mesh is outside of tube 108). The meshes 142, 144 may be formed, for example, by wrapping wire in a grid configuration around or inside a polymeric tube 108, by placing cut tube around or inside a polymeric tube 108, by being embedded within a polymeric tube 108, combinations thereof, and the like.

[0155] In some embodiments, the density of the meshes 142, 144 is relatively high in their respective ends 102, 104 (or the window size of the meshes 142, 144 is relatively small) and decreases in density (or increases in window size) toward the middle portion 106. The total winding density (e.g., the winding density of both meshes 142, 144 combined) can be lower in the middle portion 106 than in the ends 102, 104, or the total window size (e.g., the window size of both meshes 142, 144 combined) can be larger in the middle portion 106 than in the ends 102, 104. In some such embodiments, the middle portion 106 is relatively flexible compared to the ends 102, 104. In some embodiments, the meshes 142, 144 do not extend into the middle portion, and the absence of the mesh can make the middle portion 106 relatively flexible compared to the ends 102, 104. In some embodiments, as the window size increases (e.g., longitudinally along the tapered portion of the device 140), because the width of the struts and / or filaments remains substantially constant or constant or does not increase in the same proportion as the window size, the density decreases, the mesh coverage decreases, and / or the porosity increases, which can provide a change in flexibility along the longitudinal length.

[0156] The first and second meshes 142, 144 may comprise different materials, which may optimize the performance of each of the respective distal and proximal portions 102, 104 of the device 140 for a specific application of the device 140. For example, the second mesh 144 at the distal portion 104 of the device 140 may comprise a relatively flexible metal alloy to facilitate insertion through an interconnecting passage between two blood vessels, while the first mesh 142 at the proximal portion 102 of the device 140 may comprise a relatively inelastic metal alloy to provide a high degree of elasticity at the proximal portion 104 to securely hold the device 140 in place. The first and second meshes 142, 144 may comprise the same material composition (e.g., both comprise Nitinol) but different wire diameters (gauges) or strut thicknesses.

[0157] Fig.12 Another device or implant or prosthesis 150 that provides fluid flow through at least one channel is illustrated. Device 150 includes a support structure (e.g., a stent) 152 and a graft 154. As described with respect to device 100, device 150 includes a proximal portion 102, a distal portion 104, and a middle portion 106. Proximal portion 102 includes a cylindrical or substantially cylindrical portion and distal portion 104 includes a cylindrical or substantially cylindrical portion. The diameter of proximal portion 102 is less than the diameter of distal portion 104. In some embodiments, the diameter of proximal portion 102 is greater than the diameter of distal portion 104. Middle portion 106 has a conical or frustoconical shape between proximal portion 102 and distal portion 104. Stent 152 may include filaments (e.g., woven, layered), cut tubes or plates, and / or combinations thereof.

[0158] The parameters of the stent 152 may be uniform or substantially uniform across a portion and / or across multiple portions, or may vary within a portion and / or across multiple portions. For example, the stent 152 at the proximal portion 102 may include a cut tube or plate, the stent 152 at the distal portion 102 may include a cut tube or plate, and the stent 152 at the middle portion 106 may include filaments (e.g., woven or layered). Certain such embodiments may provide good fixation through good flexibility (e.g., adaptability to third channel size and dynamic stress) of the proximal portion 102 and the distal portion 104 and the middle portion 106.

[0159] The stent 152 can comprise different materials in different portions. For example, the stent 152 at the proximal portion 102 can comprise chromium cobalt and / or tantalum, the stent 152 at the distal portion 104 can comprise nitinol, and the stent 152 at the middle portion 106 can comprise nitinol. Certain such embodiments can provide good fixation and / or wall apposition by the device 150 in each deployment region (e.g., the proximal portion 102 engages the side wall of the artery, the distal portion 104 engages the side wall of the vein, and the middle portion 106 engages the side wall of the passage between the artery and the vein). In some embodiments in which the distal portion 104 is self-expanding, due to a changed vessel diameter (e.g., if the diameter of the vein increases due to increased blood pressure or blood flow), the distal portion 104 can adapt, for example, by further self-expanding.

[0160] Combinations of support structure materials and types are also possible. For example, the stent 152 at the proximal portion may include a cut tube or plate containing chromium cobalt and / or tantalum, the stent 152 at the distal portion 104 may include a cut tube or plate containing nitinol, and the stent 152 at the intermediate portion 106 may include a filament containing nitinol.

[0161] In embodiments where the stent 152 includes at least a portion comprising a cut tube or plate, the cutting pattern may be the same. For example, the cutting pattern may be the same in the proximal portion 102 and the distal portion 104, but the diameter may be proportionally changed. In some embodiments, the window size or strut density is uniform or substantially uniform within the portions 102, 104, 106, within two or more of the portions 102, 104, 106, and / or from one end of the stent 152 to the other end of the stent 152. In embodiments where the stent 152 includes at least a portion comprising a filament, the winding may be the same. For example, the winding may be the same in the proximal portion 102 and the distal portion 104, but may be changed due to a change in diameter. In some embodiments, the winding density or porosity is uniform or substantially uniform within the portions 102, 104, 106, within two or more of the portions 102, 104, 106, and / or from one end of the stent 152 to the other end of the stent 152. In embodiments where stent 152 includes at least a portion comprising cut tubes or sheets and at least a portion comprising filaments, the cutting pattern and winding can be configured to result in uniform or substantially uniform density. Non-uniformity is also possible, such as described herein.

[0162] As described with respect to tube 108, graft 154 may include material and be attached to stent 152. Graft 154 generally forms a fluid-tight passageway for at least a portion of device 150. Although illustrated only around mid-portion 106, graft 154 may extend the entire length of device 150, or may partially overlap into at least one of cylindrical ends 102, 104.

[0163] Fig.13 Another device 160 for providing fluid flow through at least one channel is illustrated. Device 160 includes a support structure (e.g., a stent) and a graft 164. As described with respect to device 100, device 160 includes a proximal portion 102, a distal portion 104, and an intermediate portion 106. Proximal portion 102 includes a tapered or frustoconical portion, and distal portion 104 includes a tapered or frustoconical portion. The diameter of the proximal end of proximal portion 102 is smaller than the diameter of the distal end of distal portion 104. In some embodiments, the diameter of the proximal end of proximal portion 102 is larger than the diameter of the distal end of distal portion 104. Intermediate portion 106 has a tapered or frustoconical shape between proximal portion 102 and distal portion 104. In some embodiments, the angles of inclination of portions 102, 104, 106 are the same or substantially the same (e.g., as shown in FIG. 1 ). Fig.13 ). In some embodiments, the angle of inclination of at least one portion is sharper or narrower than at least one other portion. The frustoconical proximal and distal portions 102, 104 may allow for better fixation in a body passage, for example because arteries tend to taper with distance from the heart and veins tend to taper with distance toward the heart, and the ends 102, 104 may be configured to correspond at least in part to such anatomical tapers.

[0164] Fig.12 An apparatus 150 is illustrated that includes a first cylindrical or straight portion, a conical or tapered portion, and a second cylindrical or straight portion. Fig.13A device 160 is illustrated that includes one or more conical or tapered portions (e.g., the entire device 160 is conical or tapered or includes multiple conical or tapered portions). In some embodiments, combinations of devices 150, 160 are possible. For example, for the remainder of the device, the device may include a cylindrical or straight portion and a conical or tapered portion. In some such embodiments, the length of the device may be between about 1 cm and about 10 cm (e.g., about 5 cm), including a cylindrical or straight portion having a diameter between about 1 mm and about 5 mm (e.g., about 3 mm) and a length between about 0.5 cm and about 4 cm (e.g., about 2 cm), and the diameter of the conical or tapered portion increases from the diameter of the cylindrical or straight portion to a diameter between about 3 mm and about 10 mm (e.g., about 5 mm) and a length between about 1 cm and about 6 cm (e.g., about 3 cm). Such a device may not have another cylindrical or conical part behind it.

[0165] As described above with respect to support structure 152, support structure 162 may include filaments (eg, woven, layered), cut tubes or sheets, the same material, different materials, and combinations thereof.

[0166] As described with respect to tube 108, graft 164 may include material and be attached to stent 162. Graft 164 generally forms a fluid-tight passage for at least a portion of device 160. Although illustrated as surrounding only mid-portion 106, graft 164 may extend the entire length of device 160, or may partially overlap at least one of frustoconical end portions 102, 104.

[0167] In some embodiments, a combination of the device 150 and the device 160 is possible. For example, the proximal portion 102 can be cylindrical or substantially cylindrical (e.g., as in the device 150), the distal portion 104 can be conical or frustoconical (e.g., as in the device 160), and the proximal portion 102 has a larger diameter than the distal end of the distal portion 104. For another example, the proximal portion 102 can be conical or frustoconical (e.g., as in the device 160), the distal portion 104 can be cylindrical or substantially cylindrical (e.g., as in the device 150), and the proximal end of the proximal portion 102 has a larger diameter than the distal portion 104. In each embodiment, the intermediate portion 106 can have a conical or frustoconical shape between the proximal portion 102 and the distal portion 104.

[0168] The example deployment device of the implantable device described herein is described in U.S. Patent Application No. 12 / 545,982 filed on August 24, 2009 and U.S. Patent Application No. 13 / 486,249 filed on June 1, 2012, the entire contents of each of which are incorporated by reference herein. The device generally includes a handle with a user-actuated trigger at the proximal end and a combination of a tubular member configured to push and / or pull to release the device after the trigger is actuated at the distal end. Other delivery devices are also possible. The delivery device may include a slidable portion on a guide wire (e.g., a guide wire manipulated by a needle-like object through tissue between an artery and a vein) and / or may be advanced through the cavity of a catheter.

[0169] Although certain embodiments and examples are shown or described herein in detail, various combinations, sub-combinations, modifications, variations, substitutions and omissions of the specific features and aspects of those embodiments are possible, some of which will now be described by way of example only.

[0170] Devices, such as stents of the device, meshes of the device, support structures of the device, and the like can be self-expanding. For example, the mesh can include a shape memory material, such as nitinol, which can recover or be configured to recover to a preset shape after undergoing deformation. In some embodiments, the stent can be manufactured into a shape that is desired in an expanded configuration and is compressible to be mounted within a sleeve for transport to a vascular site on a catheter. In order to deploy and expand the stent, the sleeve is withdrawn from the stent to allow the shape memory material to recover to a preset shape, which can fix the stent in the channel and, if the stent has sufficient radial strength, can expand the channel. The use of a balloon catheter does not require expansion of a fully self-expanding stent, but can be used, for example, to improve or optimize deployment.

[0171] The device may include one or more self-expanding portions and one or more portions that are expandable by deformation, such as using a balloon catheter. Fig.11 In the embodiment shown in FIG. 1 , the first mesh 142 may comprise stainless steel that is expandable via a balloon catheter, and the second mesh 144 may comprise nitinol that self-expands after deployment.

[0172] With respect to any of the embodiments described herein, the polymer tube 108 comprising the graft 154, 164 may include any suitable compliant or flexible polymer, such as PTFE, silicone, polyethylene terephthalate (PET), polyurethanes such as polycarbonate aromatic biodurable thermoplastic polyurethane elastomers (e.g., ChronoFlex 80A and 55D medical grade, available from AdvanSource Biomaterials of Wilmington, Massachusetts), combinations thereof, and the like. The polymer tube 108 may include a biodegradable, bioabsorbable, biocompatible polymer (e.g., polylactic acid (PLA), polyglycolic acid (PGA), polyglycolic acid-lactic acid (PLGA), polycaprolactone (PCL), polyorthoesters, polyanhydrides, combinations thereof, and the like). The polymer may be in the form of a tube prior to interacting with a support structure (e.g., a stent), or may be formed on, in, and / or around a support structure (e.g., a stent). For example, the polymer may include spun fibers, dip coatings, combinations thereof, and the like. In some embodiments, the device may omit the tube, such as when the device is deployed in a single blood vessel. In certain such embodiments, the middle portion of the stent may include a mesh having a low winding density or a large window size, while the ends of the stent include a mesh having a higher winding density or a smaller window size, the mesh being generally tubular to define a path for fluid flow through the center of the mesh. In some embodiments, the polymeric tube 108 includes an edge (e.g., including the same or different material) that can help form a fluid-tight seal between the polymeric tube 108 and the body passage. The seal can be angled, for example to account for the angled placement of the polymeric tube 108 between the body passage. In some embodiments, the polymeric tube 108 can extend longitudinally in at least one direction beyond the support structure, and the portion that extends beyond is not supported by the support structure.

[0173] The mesh may include any suitable material, such as nickel, titanium, chromium, cobalt, tantalum, platinum, tungsten, iron, manganese, molybdenum, combinations thereof (e.g., nitinol, chrome cobalt, stainless steel), etc. The mesh may include a biodegradable, bioabsorbable, or biocompatible polymer (e.g., polylactic acid (PLA), polyglycolic acid (PGA), polyglycolic acid-lactic acid (PLGA), polycaprolactone (PCL), polyorthoesters, polyanhydrides, combinations thereof, etc.) and / or glass, and may lack metal. For example, as previously described with respect to Fig.11As described, different materials may be used for portions of the mesh or within the same mesh. For example, the mesh 114 at the distal portion 104 of the device 100 and the mesh 112 at the proximal portion 102 may include different materials. For another embodiment, the mesh 112 and / or the mesh 114 may include a metal alloy (e.g., including cobalt, chromium, nickel, titanium, combinations thereof, etc.) in combination with different types of metal alloys (e.g., a shape memory alloy in combination with a non-shape memory alloy, a first shape memory alloy in combination with a second shape memory alloy different from the first shape memory alloy, a clad material (e.g., including a core containing a radiopaque material, such as titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, etc.) and / or a non-metallic material, such as a polymer (e.g., polyester fiber), carbon, and / or bioabsorbable glass fiber. In some embodiments, at least one mesh 112, 114 includes nitinol and stainless steel. Nitinol may allow for some self-expansion (eg, partial and / or complete self-expansion), and the mesh may then be further expanded, for example, using a balloon.

[0174] Although in Figure 8 , 10 1 and 11 are generally illustrated as woven filament meshes, but any other structure that can provide the desired elasticity can be used. For example, the filament layers wound in opposite directions can be fused at the ends of the filaments to provide an expandable structure. For another embodiment, the metal sheet can be cut (e.g., laser cutting, chemical etching, plasma cutting, etc.) to form perforations and then heat-set in a tubular shape, or a metal tube (e.g., a hypotube) can be cut (e.g., laser cutting, chemical etching, plasma cutting, etc.) to form perforations. The cut tube (including the cut sheet rolled into a tube) can be heat-set to impart an expansion configuration.

[0175] Can be woven or braided, or layered or otherwise arranged filament or line or ribbon are normally elongated and have cross sections such as circle, oval, square, rectangle.Example nonwoven filament can comprise the first filament layer that is wound with the first direction and the second filament layer that is wound with the second direction, and at least some filament ends are combined together (for example, by being attached to expandable ring).Example braiding pattern comprises one-on-one-under-one, one-on-two-under-two, two-on-two-under-two, and / or its combination, but other braiding patterns are also possible.At the filament intersection, filament can be wrapped spirally, cross with sliding relation, and / or its combination.Filament can be loose (for example, keep together by weaving) and / or comprise welding point, binding element such as sleeve, and / or its combination. The ends of the filaments can be bent back, curled (e.g., curled ends with radiopaque materials that can also serve as radiopaque markers, such as titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, etc.), twisted, ball welded, bonded to a ring, combinations thereof, and the like. The braided ends can include filament ends and / or filaments that are bent back, and can include open cells, fixed or unfixed filaments, welds, adhesives, or other means of fusion, radiopaque markers, combinations thereof, and the like. The parameters of the filaments can be uniform or substantially uniform throughout a portion and / or throughout multiple portions, or can vary within a portion and / or throughout multiple portions. For example, the proximal portion 102 can include a first parameter and the distal portion 104 can include a second parameter different from the first braiding pattern. For another embodiment, the proximal portion 102 and the distal portion 104 can each include a first parameter and the middle portion 106 can include a second parameter different from the parameter. For yet another embodiment, at least one of the proximal portion 102, the distal portion 104, and the intermediate portion 106 may include both a first parameter and a second parameter different from the first parameter. The filament parameters may include, for example, filament type, filament thickness, filament material, number of filaments, weave pattern, layering, winding direction, pitch, angle, crossing type, filament bonding or lack thereof, filament end treatment, woven end treatment, layered end treatment, number of layers, presence or absence of welds, radiopacity, braiding pattern, density, porosity, filament angle, braid diameter, winding diameter, and shape settings.

[0176] Tube or plate can be cut to form pillar or hole (cell) pattern, pillar is the part of the tube or plate remaining after cutting, and hole or perforation or window is the part cut off.Tube (for example, hypotube) can be directly cut, or plate can be cut and then rolled into tube.Tube or plate can be shaped before or after cutting.Tube or plate can be welded or otherwise bonded to itself, to another tube or plate, to filament, to transplant material etc.Cutting can be by laser, chemical etchant, plasma, its combination etc.Example cutting pattern comprises spiral spiral (helical spiral), weaving sample, coil, single ring, continuous ring, open hole, closed hole, its combination etc.In the embodiment comprising continuous ring, flex (flex) connector, non-flex connector and / or its combination binding ring can be used. In an embodiment comprising a continuous ring, the ring connector (e.g., flexure, non-flexure and / or a combination thereof) may intersect the ring peak, the ring valley, the middle portion of the pillar and / or a combination thereof (e.g., peak-peak, valley-valley, middle-middle, peak-valley, peak-middle, valley-middle, valley-peak, middle-peak, middle-valley). The tube or plate or a portion thereof may be ground or polished before or after cutting. For example, an internal ridge may be formed to help fluid flow. The parameters of the cut tube or plate may be uniform or substantially uniform throughout a portion and / or throughout multiple portions, or may vary within a portion and / or throughout multiple portions. For example, the proximal portion 102 may include a first parameter and the distal portion 104 may include a second parameter different from the first parameter. For another embodiment, the proximal portion 102 and the distal portion 104 may each include a first parameter and the middle portion 106 may include a second parameter different from the parameter. For another embodiment, at least one of the proximal portion 102, the distal portion 104 and the middle portion 106 may include both a first parameter and a second parameter different from the first parameter. Cutting tube or plate parameters may include, for example, radial strut thickness, circumferential strut width, strut shape, hole shape, cutting pattern, cutting type, material, density, porosity, tube diameter, and shaping.

[0177] In some embodiments, the perforations may provide a mesh having a relatively flexible middle portion and relatively rigid ends.The support structure may instead be an open cell foam disposed within the tube.

[0178] The stent, filaments of a stent graft or a portion thereof, and / or the struts of a cut stent, stent graft or a portion thereof may be surface modified, for example, to carry a drug such as a thrombus formation modifying factor, a fluid flow modifying factor, an antibiotic, etc. The stent, filaments of a stent graft or a portion thereof, and / or the struts of a cut stent, stent graft or a portion thereof may be at least partially covered with a coating including a drug such as a thrombus formation modifying factor, a fluid flow modifying factor, an antibiotic, etc., for example, embedded in a polymer layer or a series of polymer layers, which polymer layers may be the same or different than the polymer tube 108.

[0179] The filaments of a stent, stent graft, or a portion thereof, and / or the struts of a cut stent, stent graft, or a portion thereof can have a thickness (e.g., diameter) of between about 0.0005 inches and about 0.02 inches, between about 0.0005 inches and about 0.015 inches, between about 0.0005 inches and about 0.01 inches, between about 0.0005 inches and about 0.008 inches, between about 0.0005 inches and about 0.007 inches, between about 0.0005 inches and about 0.006 inches, between about 0.0005 inches and about 0.005 inches, between about 0.0005 inches and about 0.004 inches, between about 0.0005 inches and about 0.006 ... inch and about 0.003 inch, between about 0.0005 inch and about 0.002 inch, between about 0.0005 inch and about 0.001 inch, between about 0.001 inch and about 0.02 inch, between about 0.001 inch and about 0.015 inch, between about 0.001 inch and about 0.01 inch, between about 0.001 inch and about 0.008 inch, between about 0.001 inch and about 0.007 inch, between about 0.001 inch and about 0.006 inch, between about 0.001 inch and about 0.005 inch, between about 0.001 inch and about 0.004 inch, between about 0.001 inch and about 0.006 inch, between about 0.001 inch and about 0.005 inch, between about 0.001 inch and about 0.004 inch, between about 0.001 inch and about 0.006 inch, between about 0.001 inch and about 0.006 inch, between about 0.001 inch and about 0.005 inch, between about 0.001 inch and about 0.006 ... 0.001 inch and about 0.003 inch, between about 0.001 inch and about 0.002 inch, between about 0.002 inch and about 0.02 inch, between about 0.002 inch and about 0.015 inch, between about 0.002 inch and about 0.01 inch, between about 0.002 inch and about 0.008 inch, between about 0.002 inch and about 0.007 inch, between about 0.002 inch and about 0.006 inch, between about 0.002 inch and about 0.005 inch, between about 0.002 inch and about 0.004 inch, between about 0.002 inch and about 0.003 ...3 inch and about 0.004 inch 0.003 inches and about 0.02 inches, between about 0.003 inches and about 0.015 inches, between about 0.003 inches and about 0.01 inches, between about 0.003 inches and about 0.008 inches, between about 0.003 inches and about 0.007 inches, between about 0.003 inches and about 0.006 inches, between about 0.003 inches and about 0.005 inches, between about 0.003 inches and about 0.004 inches, between about 0.004 inches and about 0.02 inches, between about 0.004 inches and about 0.015 inches, between about 0.004 ...1 inches, between about 0.003 inches and about 0.008 inches, between about 0.003 inches and about 0.007 inches, between about 0.003 inches and about 0.006 inches, between about 0.003 inches and about 0.005 inches, between about 0.003 inches and about 0.004 inches, between about 0.004 inches and about 0.02 inches, between about 0.004 inches and about 0.015 inches, between about 0.0040.004 inches and about 0.008 inches, between about 0.004 inches and about 0.007 inches, between about 0.004 inches and about 0.006 inches, between about 0.004 inches and about 0.005 inches, between about 0.005 inches and about 0.02 inches, between about 0.005 inches and about 0.015 inches, between about 0.005 inches and about 0.01 inches, between about 0.005 inches and about 0.008 inches, between about 0.005 inches and about 0.007 inches, between about 0.005 inches and about 0.006 inches, between about 0.006 inches and about 0.02 inches, between about 0.006 inches and about 0.015 inches, between about 0.006 inches and about 0.01 inches 01 inch, between about 0.006 inch and about 0.008 inch, between about 0.006 inch and about 0.007 inch, between about 0.007 inch and about 0.02 inch, between about 0.007 inch and about 0.015 inch, between about 0.007 inch and about 0.01 inch, between about 0.007 inch and about 0.008 inch, between about 0.008 inch and about 0.02 inch, between about 0.008 inch and about 0.015 inch, between about 0.008 inch and about 0.01 inch, between about 0.01 inch and about 0.02 inch, between about 0.01 inch and about 0.015 inch, or between about 0.015 inch and about 0.02 inch. Other thicknesses are also possible, including thicknesses greater than or less than the thicknesses identified. Filaments and / or struts comprising certain materials (e.g., biodegradable materials, materials with lower restoring forces, etc.) may be thicker than the thickness identified.

[0180] For example, the thickness of the filaments and / or struts can be based on at least one of the following: device or device portion size (e.g., diameter and / or length), porosity, radial strength, material, number of filaments and / or struts, cutting pattern, weaving pattern, layering pattern, etc. For example, larger filament and / or strut thicknesses (e.g., greater than about 0.006 inches) can be used for large devices or device portions used to treat large vessels such as coronary vessels, medium filament and / or strut thicknesses (e.g., between about 0.003 inches and about 0.006 inches) can be used for medium devices or device portions used to treat medium vessels such as peripheral vessels, and small filament and / or strut thicknesses (e.g., less than about 0.003 inches) can be used for small devices or device portions used to treat small vessels such as veins and neural vessels.

[0181] The inner or outer diameter of the stent, stent graft, or the first end, second end, middle portion, or sub-portions thereof, e.g., to account for filament or strut thickness, can be between about 1 mm and about 12 mm, between about 1 mm and about 10 mm, between about 1 mm and about 8 mm, between about 1 mm and about 6 mm, between about 1 mm and about 4 mm, between about 1 mm and about 2 mm, between about 2 mm and about 12 mm, between about 2 mm and about 10 mm, between about 2 mm and about 8 mm, Between about 2 mm and about 6 mm, between about 2 mm and about 4 mm, between about 4 mm and about 12 mm, between about 4 mm and about 10 mm, between about 4 mm and about 8 mm, between about 4 mm and about 6 mm, between about 6 mm and about 12 mm, between about 6 mm and about 10 mm, between about 6 mm and about 8 mm, between about 8 mm and about 12 mm, between about 8 mm and about 10 mm, or between about 10 mm and about 12 mm. Certain such diameters may be suitable for treating, for example, coronary vessels. The internal diameter or external diameter of a stent, stent graft or a part thereof, for example, considering filament or strut thickness, can be between about 1mm and about 10mm, between about 1mm and about 8mm, between about 1mm and about 6mm, between about 1mm and about 4mm, between about 1mm and about 2mm, between about 2mm and about 10mm, between about 2mm and about 8mm, between about 2mm and about 6mm, between about 2mm and about 4mm, between about 4mm and about 10mm, between about 4mm and about 8mm, between about 4mm and about 6mm, between about 6mm and about 10mm, between about 6mm and about 8mm, or between about 8mm and about 10mm. Some such diameters may be suitable for treatment, for example, of a vein. The internal diameter or external diameter of a stent, stent graft or a part thereof, for example, considering filament or strut thickness, can be between about 6mm and about 25mm, between about 6mm and about 20mm, between about 6mm and about 15mm, between about 6mm and about 12mm, between about 6mm and about 9mm, between about 9mm and about 25mm, between about 9mm and about 20mm, between about 9mm and about 15mm, between about 9mm and about 12mm, between about 12mm and about 25mm, between about 12mm and about 20mm, between about 12mm and about 15mm, between about 15mm and about 25mm, between about 15mm and about 20mm, or between about 20mm and about 25mm. Some such diameters may be suitable for treatment, for example, of peripheral blood vessels.The inner diameter or outer diameter of a stent, stent graft, or a portion thereof, for example, taking into account filament or strut thickness, can be between about 20 mm and about 50 mm, between about 20 mm and about 40 mm, between about 20 mm and about 35 mm, between about 20 mm and about 30 mm, between about 30 mm and about 50 mm, between about 30 mm and about 40 mm, between about 30 mm and about 35 mm, between about 35 mm and about 50 mm, between about 35 mm and about 40 mm, between about 40 mm and about 50 mm. Some such diameters may be suitable for treatment, for example, of an aortic vessel. Other diameters are also possible, including diameters greater than or less than the diameter confirmed. The diameter of a device may refer to the diameter of a first end, a second end, or a middle portion, each of which may be in an expanded or unexpanded form. When all portions of a device are in an expanded or unexpanded form, the diameter of a device may refer to the average diameter of the device.

[0182] The length of the stent, stent graft, or the first end, the second end, the middle portion, or a sub-portion thereof can be between about 5 mm and about 150 mm, between about 5 mm and about 110 mm, between about 5 mm and about 70 mm, between about 5 mm and about 50 mm, between about 5 mm and about 25 mm, between about 5 mm and about 20 mm, between about 5 mm and about 10 mm, between about 10 mm and about 150 mm, between about 10 mm and about 110 mm, between about 10 mm and about 70 mm, between about 10 mm and about 50 mm, between about 10 mm and about 25 mm, between about 5 mm and about 20 mm, between about 5 mm and about 10 mm, between about 10 mm and about 20 mm, between about 20 mm and about 25 mm. 100mm, between about 20mm and about 70mm, between about 20mm and about 50mm, between about 20mm and about 25mm, between about 25mm and about 150mm, between about 25mm and about 110mm, between about 25mm and about 70mm, between about 25mm and about 50mm, between about 50mm and about 150mm, between about 50mm and about 110mm, between about 50mm and about 70mm, between about 70mm and about 150mm, between about 70mm and about 110mm, or between about 110mm and about 150mm. Other lengths are also possible, including lengths greater or less than the lengths identified.

[0183] The porosity of the stent, stent graft, or first end, second end, middle portion, or sub-portion thereof can be between about 5% and about 95%, between about 5% and about 50%, between about 5% and about 25%, between about 5% and about 10%, between about 10% and about 50%, between about 10% and about 25%, between about 25% and about 50%, between about 50% and about 95%, between about 50% and about 75%, between about 50% and about 60%, between about 60% and about 95%, between about 75% and about 90%, between about 60% and about 75%, and combinations thereof. The density of the stent can be the inverse of the porosity of the stent. The porosity of the stent portion covered by the graft can be about 0%. For certain portions of the stent, the porosity can vary with purpose. For example, the middle section may have low porosity to increase fluid flow through the device, while the ends may have lower porosity to increase flexibility and wall attachment.

[0184] The radial strength or compressive strength of the stent, stent graft, or first end, second end, middle portion, or sub-portions thereof can be between about 0.1 N / mm and about 0.5 N / mm, between about 0.2 N / mm and about 0.5 N / mm, between about 0.3 N / mm and about 0.5 N / mm, between about 0.1 N / mm and about 0.3 N / mm, between about 0.1 N / mm and about 0.2 N / mm, between about 0.2 N / mm and about 0.5 N / mm, between about 0.2 N / mm and about 0.3 N / mm, or between about 0.3 N / mm and about 0.5 N / mm.

[0185] Certain parameter values ​​of a stent, stent graft, or first end, second end, middle portion, or sub-portion thereof can be associated (e.g., proportional). For example, the thickness of a strut or filament to the diameter of the device portion containing the strut or filament can be between about 1:10 and about 1:250, between about 1:25 and about 1:175, or between about 1:50 and about 1:100. For another embodiment, the length of a device or portion thereof to the diameter of the device or portion thereof can be between about 1:1 and about 50:1, between about 5:1 and about 25:1, or between about 10:1 and about 20:1.

[0186] Portions of the device may include radiopaque materials. For example, the filaments and / or struts of a stent, stent graft, or first end, second end, middle portion, or sub-portion thereof may include titanium, tantalum, rhenium, bismuth, silver, gold, platinum, iridium, tungsten, combinations thereof, and the like (e.g., at least partially made thereof). For another embodiment, the filaments and / or struts of a stent, stent graft, or portion thereof may include a material having a density greater than about 9 grams / cubic centimeter (e.g., at least partially made thereof). Separate radiopaque markers may be attached to certain components of the device. For example, radiopaque markers may be added to the proximal end of the device or its components (e.g., the proximal end component of the middle portion, the proximal end component of the distal portion), the distal end of the device or its components (e.g., the distal end component of the middle portion, the distal end component of the proximal portion), and / or other components. For example, radiopaque markers between the ends of the device may be used to demarcate transitions between materials, portions, and the like. The radiopaqueness may vary across the length of the device. For example, the proximal portion may have a first radiopacity (e.g., due to the distal portion material and / or a separate marker) and the distal portion may have a second radiopacity different from the first radiopacity (e.g., due to the distal portion material and / or a separate marker).

[0187] In some embodiments, the device comprises a polymer tube and no support structure is provided.The middle portion of such a device can be relatively more flexible than the end portions by, for example, reducing the wall thickness of the polymer tube in the middle portion.

[0188] When a mesh or other support structure is provided in conjunction with a polymeric tube, the support structure may be located around the outside of the tube, in the inner bore of the tube, or embedded in the tube wall. More than one support structure may be provided, in which case each support structure may have a different position relative to the tube.

[0189] One or both ends of the device may include a fixing element such as a hook, protuberance or barb configured to catch or grip the inner wall of the blood vessel. In the absence of a fixing element, the radial force of the expanded rear end may be sufficient to catch or grip the inner wall of the blood vessel.

[0190] There need not be a clearly defined transition between the middle portion and the end portions. For example, the mesh type, material, wall thickness, flexibility, etc. may change gradually from the end portions towards the middle portion or from the middle portion towards the end portions.

[0191] For example, as described with respect to devices 134, 140, the flexibility of the device can increase gradually when moving from the end toward the middle portion. The change in flexibility can be due to changes in mesh density (e.g., winding density, window size), tube thickness, or other factors. The flexibility of the device can be uniform or substantially uniform along the entire length of the support structure (e.g., stent), or along certain portions of the support structure (e.g., along the entire end, along the entire middle portion, along one end and the middle portion but not along the other end, etc.).

[0192] Although the device described herein may be particularly suitable for use as a shunt through a blood vessel in a percutaneous procedure, the device may be used in many other medical applications. For example, the device may be used in angioplasty to treat an occluded blood vessel with a twisted or kinked path, or where the blood vessel may be subject to deflection or deformation at or near the location of the stent. For example, the stent may also be used to repair damaged blood vessels during a percutaneous procedure, during an aortic graft, or after a perforation. In some such cases, in response to the movement of the blood vessel, the middle portion of the device may allow the device to conform to the shape and deformation of the blood vessel, which has a reduced risk of fatigue failure while keeping the ends mounted or fixed in place. For another embodiment, the device may 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 infusions of cancer treatments, which may damage the blood vessel).

[0193] Refer again Figure 4 and 7 , occlusive material 251 can be used to help inhibit or prevent the reversal of arterial blood flow. As will now be described in further detail, additional or other methods and systems can be used to inhibit or prevent the reversal of arterial blood flow, or, in other words, to inhibit or prevent arterial blood flow that now flows into a vein from flowing in the vein in the normal pre-procedure direction of blood flow so that oxygenated blood bypasses downstream tissues such as the foot.

[0194] In the absence of treatment, peripheral vascular disease (PVD) can progress to critical limb ischemia (CLI), which is characterized by profound chronic pain and massive tissue loss that limits revascularization options and frequently leads to amputation. CLI is estimated to have an incidence of approximately 50-100 / 100,000 / year and is associated with a mortality rate as high as 20% at 6 months after onset.

[0195] Interventional radiologists have actively attempted to treat CLI by attempting to open chronic total occlusions (CTOs) or by bypassing CTOs in the subintimal space using products such as the Medtronic Pioneer catheter, which tunnels a wire into the subintimal space proximal to the CTO and then attempts to re-enter the vessel distal to the occlusion. Once the wire is in place, the user can optionally create a wider pathway and then place a stent to provide a bypass catheter across the occlusion. If the wire can pass through the occlusion, conventional approaches to treat PAD such as percutaneous transluminal angioplasty (PTA), stenting, and drug eluting balloons (DEB) can also or alternatively be used in the treatment of CLI.

[0196] From amputee-coalition.org, here are some statistics on the CLI problem:

[0197] In the United States, nearly two million people live with limb loss.

[0198] Among those who survived with limb loss, the main causes were:

[0199] o Vascular disease (54%) (including diabetes and peripheral arterial disease (PAD)),

[0200] o Trauma (45%), and

[0201] oCancer (less than 2%).

[0202] Approximately 185,000 amputations occur each year in the United States.

[0203] In 2007, hospital costs related to amputations totaled more than $6.5 billion.

[0204] Survival rates after amputation vary based on many factors. Those who have an amputation due to vascular disease (including PAD and diabetes) face 30-day mortality rates reported to be between 9% and 15% and long-term survival rates of 60% at 1 year, 42% at 3 years, and 35%-45% at 5 years.

[0205] Almost half of people who lose a limb to vascular disease will die within 5 years. This is higher than the 5-year mortality rate experienced by people with colorectal cancer, breast cancer, and prostate cancer.

[0206] Up to 55% of people with diabetes who have a lower limb amputation will require a second leg amputation within 2 to 3 years.

[0207] Since the early twentieth century, CLI has been treated surgically by open-leg venous arterialization. Over the years, many small series of clinical trials using such open-leg surgical approaches have been published, as summarized by Lu et al. in a 2006 meta-analysis article entitled "Meta-analysis of the clinical effectiveness of venous arterialization for salvage of critically ischemic limbs" in European Journal of Vascular and Endovascular Surgery, Volume 31, Pages 493-499. The article had the following results and conclusions:

[0208] ·result:

[0209] o A total of 56 studies were selected for comprehensive review. No randomized controlled trials (RCTs) were identified. Seven patient series matching selection criteria included 228 patients. Overall 1-year foot preservation was 71% (95% CI: 64%-77%) and 1-year secondary patency was 46% (95% CI: 39%-53%). Most patients who avoided major amputation experienced successful wound healing, absence of rest pain, and absence of major complications.

[0210] ·in conclusion:

[0211] o Based on limited evidence, venous arterialization is considered a viable alternative before major amputation in patients with “inoperable” chronic critical lower limb ischemia.

[0212] Among other diseases described herein, the methods and systems described herein can be used to create an arteriovenous (AV) fistula in the below-the-knee (BTK) vasculature using an endovascular, minimally invasive surgical approach. Such an approach can be appropriate for patients who: (i) have a clinical diagnosis of symptomatic critical limb ischemia as defined by Rutherford 5 or 6 (severe ischemic ulcers or frank gangrene); (ii) have been evaluated by a vascular surgeon and interventionist and determined that surgical or endovascular treatment is not possible; and / or (iii) have a clear indication for major amputation.

[0213] In some embodiments, the system or kit optionally includes one or more of the following components: a first ultrasound catheter (e.g., an arterial catheter, a transmitting catheter containing a needle, etc.); a second ultrasound catheter (a venous catheter, a target catheter, etc.); and a prosthesis (e.g., a nitinol stent graft coated in a delivery system (e.g., a 7Fr (approximately 2.3 mm) delivery system)). The system or kit optionally further includes an ultrasound system, a control system (e.g., a computer). Some users may already have a suitable ultrasound system that can be connected to the ultrasound catheter (one or more). 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.

[0214] Fig.14A 1 is a schematic side cross-sectional view of an example embodiment of an ultrasound emitting catheter 170, which includes a needle 172 (e.g., a first ultrasound catheter, an arterial catheter (e.g., if the needle extends from an artery into a vein), a venous catheter (e.g., if the needle extends from a vein into an artery)). The catheter 170 is placed into the artery, and the needle 172 is inside the lumen of the catheter 170 in a retracted state. The catheter 170 can be advanced over a guidewire (e.g., a 0.014 inch (approximately 0.36 mm) guidewire) and / or placed through a sheath in an artery (e.g., a femoral artery) and advanced until the point of complete occlusion of the artery (in the tibial artery). The catheter 170 includes a handle 174 including a pusher ring 176. Longitudinal or distal advancement of the pusher ring 176 can advance the needle 172 out of the lumen of the catheter 170, out of the artery and into the vein, as described herein. Other advancement mechanisms for the needle 172 are also possible (e.g., rotating, motorized, etc.). Before, after, and / or during advancement of needle 172, a guide wire (e.g., a 0.014 inch (approximately 0.36 mm) guide wire) may be placed through needle 172 (e.g., as described with respect to Figure 3 The guide wire 14 is described above and may be referred to as a crossing wire.

[0215] Fig. 14B It is within circle 14B Fig.14A FIG. 1 is an enlarged schematic side cross-sectional view of a distal portion of an ultrasound transmitting catheter 170 of FIG. After advancement or firing, a needle 172 extends radially outward from a lumen 173 of the catheter 170. In some embodiments, the lumen 173 ends near an ultrasound transmitting device 178. The needle 172 can extend along a path that is aligned with (e.g., parallel to) a path of a directed ultrasound signal emitted by the ultrasound transmitting device 178. Fig. 14B Also shown is a lumen 175 which may be used to accommodate a guidewire for advancing catheter 170 to a desired location.

[0216] Fig.15A is a schematic side view of an example embodiment of an ultrasound target catheter 180 (eg, a second ultrasound catheter, an arterial catheter (eg, if a needle extends from a vein into an artery)), a venous catheter (eg, if a needle extends from an artery into a vein). Fig. 15B It is within circle 15B Fig.15A An enlarged schematic side cross-sectional view of an ultrasound target catheter 180 is shown. Fig. 15C Is within circle 15C Fig.15A 1. An enlarged schematic side cross-sectional view of an ultrasound target catheter 180 of FIG. 1. The catheter 180 can be advanced over a guidewire (e.g., a 0.014 inch (approximately 0.36 mm) guidewire) and / or placed through a sheath in a vein (e.g., a femoral vein) and advanced until close to and / or parallel to the distal end of the catheter 170 and / or the point of occlusion in the artery (e.g., in the tibial vein). The catheter 180 includes an ultrasound receiving transducer 182 (e.g., an omnidirectional ultrasound receiving transducer) that can act as a target in the vein for aligning the needle 172 of the catheter 170. The catheter 180 can stay in place or remain stationary or substantially stationary while the catheter 170 is rotated or moved longitudinally to obtain a good or optimal ultrasound signal indicating that the needle 172 is aligned with the catheter 180 and in the direction of the catheter 180.

[0217] The catheters 170, 180 may be connected to an ultrasound transceiver that is connected to and controlled by a computer running transceiver software. As further described herein, the catheter 170 includes a planar or directional ultrasound transmitter 178 that is configured to send an ultrasound signal having a low angular spread or a tight beam (e.g., a small beam width) in the direction of the needle 172 path after being advanced from the lumen 173 of the catheter 170. The catheter 180 includes an omnidirectional (360 degree) ultrasound receiver 182 that is configured to act as a target for the ultrasound signal emitted by the directional transmitter 178 of the catheter 170. Rotate the catheter 170 until a peak ultrasound signal is displayed, which indicates that the needle 172 is aligned with the catheter 180, so that after the needle 172 is extended (e.g., by longitudinally advancing the ring 176 of the handle 174), the needle 172 can pass through the artery in which the catheter 170 resides, through the interstitial tissue, and enter the vein in which the catheter 180 resides.

[0218] Fig.16 is an example embodiment of a diagram for detecting catheter alignment, as may be displayed on a display device of an ultrasound system (eg, a screen of a laptop, tablet, smartphone, combinations thereof, and the like). Fig.16The diagram in FIG. 1 shows that the signal originating from the transmitting catheter in the artery has been received by the receiving catheter in the vein. The second frequency envelope from the right is the received signal. The distance from the left side of the illustrated screen to the leading edge of the second frequency envelope may represent the distance between the catheters. The operator may move the catheter in the artery both rotationally and longitudinally, for example, until the second envelope is maximal, which indicates that the catheter is correctly oriented.

[0219] Fig.17 is a schematic side view of an example embodiment of a prosthesis (eg, stent, stent graft) delivery system 190. In some embodiments, the delivery system 190 is a 7 Fr (approximately 2.3 mm) delivery system. Fig.18 is a schematic side view of an example embodiment of a prosthesis (e.g., stent, stent graft) 200. Fig.17 In the embodiment of the present invention, a prosthesis (e.g., prosthesis 200, other prostheses described herein, etc.) is in a compressed or curled state near the distal end 192 of the delivery system 190. In some embodiments, the prosthesis 200 includes a shape memory stent covered with a graft material, such as described above. Once the traverse line extends from the artery to the vein, the delivery system 190 can be advanced across the traverse line, such as due to being advanced through the needle 172 as described herein. The prosthesis 200 can be deployed from the delivery system 190, such as by squeezing the trigger handle 194 of the delivery system 190, retracting the outer cover sheath proximally and / or advancing the prosthesis 200 distally. The prosthesis 200 can establish a flow path between the artery and the vein and through the interstitial tissue. Other types of delivery systems and prostheses are also possible.

[0220] Refer again Fig.17, some non-limiting example dimensions of the delivery system 190 are provided. The travel distance 196 of the trigger handle 194 can be, for example, between about 0.4 inches (about 1 cm) and about 12 inches (about 30 cm), between about 1 inch (about 2.5 cm) and about 8 inches (about 20 cm), or between about 2 inches (about 5 cm) and about 6 inches (about 15 cm) (e.g., about 2 inches (about 5 cm)). In some embodiments, the travel distance 196 of the trigger handle 194 is at least as long as the length of the prosthesis 200 to be deployed (e.g., in the radially expanded state). In some embodiments, a transmission or other mechanism can be used to reduce the travel distance 196 of the trigger handle 194 to be less than the length of the prosthesis 200 to be deployed (e.g., in the radially expanded state). For example, the distance 196 can be adjusted based on at least one of the following: the length of the prosthesis 200 to be deployed, the degree of vertical deformation of the prosthesis 200 to be deployed, the deployment mechanism (e.g., whether the outer sheath is retracted proximally, whether the prosthesis 200 is pushed forward distally, or both, whether the delivery system 190 includes a transmission mechanism, etc.), a combination thereof, etc. The length 197 of the outer sheath or catheter portion can be, for example, between about 40 inches (about 1,020 mm) and about 50 inches (about 1,270 mm), between about 46 inches (about 1,170 mm) and about 47 inches (about 1,190 mm), or between about 46.48 inches (about 1,180 mm) and about 46.7 inches (about 1,186 mm). The total length 198 of the delivery system 190 from the proximal tip to the distal tip can be, for example, between about 40 inches (about 1,000 mm) and about 60 inches (about 1,500 mm). For example, the lengths 197, 198 can be adjusted based on at least one of the following: the length of the prosthesis 200 to be deployed, the degree of vertical deformation of the prosthesis 200 to be deployed, the height of the patient, the location of the occlusion being treated, a combination thereof, etc. In some embodiments, spacing the trigger handle 194 from the vascular access point, for example, between about 10 cm and about 30 cm (e.g., at least about 20 cm) can advantageously provide a user with easier handling or management. In certain such embodiments, the length 197 can be between about 120 cm and about 130 cm (e.g., for an antegrade approach) or between about 150 cm and about 180 cm (e.g., for a contralateral approach).

[0221] Refer again Fig.18, some non-limiting example dimensions of the prosthesis 200 are provided, depending on the environment at least in the compressed state. The thickness 201 of the structural struts can be, for example, between about 0.05 mm and about 0.5 mm or between about 0.1 mm and about 0.2 mm (e.g., about 0.143 mm). The spacing 202 between the struts of the structural struts can be, for example, between about 0.005 mm and about 0.05 mm or between about 0.01 mm and about 0.03 mm (e.g., about 0.025 mm). The thickness 203 of the connecting struts can be, for example, between about 0.05 mm and about 0.5 mm or between about 0.1 mm and about 0.2 mm (e.g., about 0.133 mm). The longitudinal length 204 of the structural member can be, for example, between about 1 mm and about 5 mm or between about 2.5 mm and about 3 mm (e.g., about 2.8 mm). The longitudinal length 205 between structural components can be, for example, between about 0.25 mm and about 1 mm or between about 0.5 mm and about 0.6 mm (e.g., about 0.565 mm). The length 206 of the struts within the structural components, including all portions that are wound back and forth, can be, for example, between about 25 mm and about 100 mm or between about 65 mm and about 70 mm (e.g., about 67.62 mm). The total longitudinal length of the prosthesis 200 can be, for example, between about 25 mm and about 150 mm or between about 50 mm and about 70 mm (e.g., about 62 mm). As described herein, many laser cut struts, woven stents, and combinations thereof, including various sizes, are possible. The struts described herein may include wires or filaments or portions that are not cut from a hypotube or plate.

[0222] The proximal and / or distal ends of the prosthesis 200 may optionally include a ring 210. The ring 210 may, for example, help secure the prosthesis 200 in an artery and / or vein. The circumferential width of the ring 210 may, for example, be between about 0.25 mm and about 1 mm or between about 0.5 mm and about 0.75 mm (e.g., about 0.63 mm). The longitudinal length 212 of the ring 210 may, for example, be between about 0.25 mm and about 2 mm or between about 0.5 mm and about 1 mm (e.g., about 0.785 mm). In some embodiments, the ratio of the total length of the prosthesis 200 to the longitudinal length 212 of the ring 210 may be between about 50:1 and about 100:1 (e.g., about 79:1). The dimensions 211, 212 of the ring 210 may be adjusted, for example, based on at least one of the following: strut thickness, diameter of the prosthesis (e.g., relative to the vessel), total length of the prosthesis, material, shaping properties, combinations thereof, and the like.

[0223] Fig.19is a schematic side view of another example embodiment of a prosthesis 220. Prosthesis 200 can have the shape of prosthesis 220, such as in a radially expanded state (eg, after deployment from delivery system 190). Fig.19 Example shapes of a prosthesis 220 are illustrated including a first portion 221 and a second portion 225. The first portion 221 has a substantially cylindrical or cylindrical shape having a length 222 between about 15 mm and about 25 mm (e.g., about 21 mm) and a diameter 223 between about 2.5 mm and about 5 mm (e.g., about 3.5 mm). The second portion 225 has a substantially frustoconical or frustoconical shape having a length 226 between about 30 mm and about 50 mm (e.g., about 41 mm) and a maximum diameter 227 between about 4 mm and about 10 mm, between about 4 mm and about 7 mm (e.g., about 5.5 mm), etc. The angle at which the second portion 225 tapers away from the first portion 221 can be between about 0.02 degrees and about 0.03 degrees (e.g., about 0.024 degrees).

[0224] Further details regarding prostheses that may be used in accordance with the methods and systems described herein are described in US Patent Application No. 13 / 791,185, filed on March 8, 2013, which is hereby incorporated by reference in its entirety.

[0225] Figures 20A-20H Schematically illustrates an example embodiment of a method of achieving retrograde perfusion. The process will be described with respect to peripheral vascular system such as the calf, but may also be adapted to other body cavities (e.g., cardiac, other peripheral, etc.). For clarity, certain steps such as anesthesia, incision details, suturing, etc. may be omitted. In some embodiments, the process may be performed from vein to artery (e.g., using an intravenous catheter from below).

[0226] Access to the femoral artery and femoral vein is obtained. For example, using the Seldinger technique, a guide sheath (e.g., 7Fr (approximately 2.3mm)) is inserted into the femoral artery and a guide sheath (e.g., 6Fr (approximately 2mm)) is inserted into the femoral vein. A guide wire (e.g., 0.014 inches (approximately 0.36mm), 0.035 inches (approximately 0.89mm), 0.038 inches (approximately 0.97mm)) is inserted through the guide sheath in the femoral artery and directed into the distal portion of the diseased artery 300 posterior to the tibial or anterior to the tibial. A second guide wire (e.g., 0.014 inches (approximately 0.36mm), 0.035 inches (approximately 0.89mm), 0.038 inches (approximately 0.97mm)) or a snare is inserted through the guide sheath in the femoral vein. In embodiments in which a snare is used, the third guide wire, fourth guide wire, etc. described herein are accurate - even though the numbering may not be continuous.

[0227] A venous access needle is percutaneously inserted into a target vein, such as the tibial vein (e.g., the proximal tibial vein (PTV)). In some embodiments, the venous access needle can be guided under ultrasound. In some embodiments, a contrast agent can be injected into the saphenous vein toward the foot (retrograde), and the contrast agent will then flow into the PTV. This flow path can be captured using fluoroscopy so that the venous access needle can be guided by fluoroscopy instead of or in addition to ultrasound.

[0228] The target vein can be accessed proximally and distally (e.g., several inches or centimeters) below where the launching catheter 310 is likely to reside. In some embodiments, the target vein can be mid-ankle. Once the venous access needle is in the vein, a third guidewire (or "second" guidewire, in which case a snare is used instead of the second guidewire) is inserted through the venous access needle and advanced antegrade in the target vein until it reaches the femoral vein. This entry method can advantageously reduce problems caused by retrograde advancement of the wire through the venous valves, which are described in further detail below. For example, the third guidewire is snared using fluoroscopy guidance and pulled through the femoral vein. The target catheter 320 is inserted into the femoral vein sheath over the already snared third guidewire. The target catheter 320 is advanced into the venous system over the third guidewire until the target catheter is close to and / or parallel to the guidewire and / or adjacent to the occlusion 304 in the distal portion of the diseased artery either the posterior tibial or anterior tibial artery, such as Fig. 20A is shown in .

[0229] In some embodiments, the third guidewire may include an ultrasound receiving transducer (e.g., omnidirectional) mounted to provide a target for the signal transmitted by the transmitting catheter 310 or the target catheter 320 can be advanced over the third guidewire, either of which may allow for omission of certain techniques (e.g., femoral vein entry, introduction of a venous introducer sheath, insertion of a second guidewire, antegrade advancement of the third guidewire until the femoral vein, capture of the third guidewire, advancement of the target catheter 320 over the third guidewire).

[0230] In some embodiments, the PTV can be accessed directly, for example using ultrasound, which can allow the target catheter 320 to be placed directly into the PTV, for example using a small sheath, which can allow certain techniques to be omitted (e.g., femoral vein entry, introduction of a venous introducer sheath, insertion of a second guidewire, antegrade advancement of a third guidewire until the femoral vein).

[0231] In some embodiments, catheter 320 is not an over-the-wire catheter, but includes a guidewire and an ultrasound receiving transducer (e.g., omnidirectional). Catheter 320 can be inserted as a third guidewire, as a second guidewire, or as a guidewire through a small sheath when directly accessing the PTV, as discussed above.

[0232] Ultrasonic transducers typically include two electrodes comprising surfaces separated by a vibrating ceramic. Incoming or received ultrasonic signal waves can be coupled into length-extending modes such as Fig.21 As shown in . Fig.21 350。It is a schematic perspective view of an example embodiment of an ultrasound receiving transducer 350. If the proximal end or top end 352 of the transducer 350 and the distal end or bottom end 354 of the transducer are conductive and electrically connected to the wire, the transducer can receive ultrasonic signals. In some embodiments, the length of the transducer 350 is between about 0.1mm and about 0.4mm (e.g., about 0.25mm). In some embodiments, the overlapping length 358 of the transducer 350 is between about 0.1mm and about 0.3mm (about 0.2mm). In some embodiments, the diameter of the transducer 350 is similar, substantially similar or identical to the guide wire on which it is installed. In some embodiments, a row or a series of laminated materials can enhance the signal receiving capability of the transducer 350.

[0233] In some embodiments, a guidewire including an ultrasound receiving transducer can include a piezoelectric film (eg, including plastic), which can enhance the signal receiving capabilities of the transducer. Fig. 22 is a schematic cross-sectional view of another example implementation of an ultrasound receive transducer 360 . Fig. 22 The ultrasonic receiving transducer 360 shown in FIG. 360 includes an optional cavity 368. The ultrasonic receiving transducer 360 includes a series of layers 362, 364, and 366. Layer 362 may include a polymer (e.g., polyvinylidene fluoride (PVDF)) layer. Layer 364 may include an inorganic compound (e.g., tungsten carbide) layer. Layer 366 may include a polymer (e.g., polyimide) layer. The thickness of layer 366 may be between about 25 micrometers (μm or micrometers) and about 250 μm (e.g., at least about 50 μm).

[0234] The launch catheter 310 is advanced over the guidewires in the femoral and tibial arteries proximal to and near the occlusion 304, as shown in FIG. Fig. 20B 304, depending on the suitability of that portion of the anatomy for a retrograde perfusion procedure. In some embodiments, catheter 310 may be placed in a distal portion of the posterior tibial artery or the anterior tibial artery, such as adjacent catheter 320. In some embodiments, catheter 310 may be placed within a few inches or centimeters of the ankle.

[0235] The transmitting catheter 310 transmits a directional ultrasound signal. Fig. 20CThe launch catheter 310 is rotated and moved longitudinally as shown by the middle arrows 311, 312 until the signal is received by the target catheter 320. Once the signal is received, indicating alignment, extension of the needle from the launch catheter 310 will result in successful entry into the vein, and the traversing needle 314 is advanced out of the launch catheter 310, out of the tibial artery 300 and into the tibial vein 302, as shown in FIG. Fig.20D The accuracy of placing the transverse needle 314 to form a fistula between the artery 300 and the vein 302 can be confirmed, for example, using contrast and fluoroscopy.

[0236] In some embodiments, the ultrasound signal can be used to determine the distance between the artery 300 and the vein 302. Fig.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 indication of the distance between the conduits.

[0237] Refer again Fig.16 , the display device can graphically display the signal alignment peak to allow the user to determine the alignment position. In some embodiments, the signal alignment can change color above or below a threshold, such as from red to green. In some embodiments, for example, when the alignment signal crosses a threshold, an audio signal can be emitted, which can allow the user to stay focused on the patient rather than essentially continuously monitoring the screen.

[0238] In some embodiments, a horizontal line on the screen may move up during the procedure to indicate the maximum signal value or peak value reached at that point. This line may be referred to as "peak hold." If a larger signal value is reached, the horizontal line moves to match that higher value. If no manipulation is able to raise the peak value above the horizontal line, then that may indicate maximum alignment. If the signal peak drops a certain amount below the horizontal line, then the catheter may have moved and is no longer properly aligned. Because the alignment level indicated by the horizontal line has previously been achieved during the procedure, the user knows that such an alignment level can be achieved by further rotational manipulation and / or longitudinal manipulation.

[0239] A fourth guidewire 316 (e.g., 0.014 inch (approximately 0.36 mm)) (or "third" guidewire, in which case a snare is used instead of the second guidewire) is placed through the lumen of the catheter 310 across the needle 314 and into the tibial vein 302 in a retrograde direction (of the vein 302) toward the foot, such as Fig.20E . External cuff pressure may be applied above the needle traversal point to reduce flow in the artery 300 to inhibit or prevent hematoma formation, and / or to cause venous congestion to facilitate valve penetration. The catheters 310, 320 may be removed, leaving the guidewire 316 in place, extending from the introducer sheath in the femoral artery, through the arterial tree, and into the tibial vein 302.

[0240] Certain techniques for passing the guidewire 316 from the artery 300 to the vein 302 may also be used instead of or in addition to the directional ultrasound techniques described herein.

[0241] In some embodiments, a tourniquet can be applied to the leg, which can increase the diameter of the vein. In some embodiments, an occlusive agent (e.g., Figure 4 and 7 As discussed, occluding balloons, etc., can be used to increase the diameter of the vein. For example, venous flow can be reversed, causing the vein to expand. A larger vein diameter can create a larger target for the traversing needle 314, making it easier to enter the vein 300 using the traversing needle 314.

[0242] In some embodiments, a PTA balloon can be used in the target vein, and a needle catheter (e.g., Outback, available from Cordis) can be targeted to the PTA balloon under fluoroscopy. The traversing needle 314 can pierce the PTA balloon, and a decrease in the PTA balloon pressure can confirm proper alignment of the traversing needle 314. The PTA balloon can increase the diameter of the vein, creating a larger target for the traversing needle 314, making it easier to enter the vein 300 using the traversing needle 314. A guidewire 316 can be advanced through the traversing needle 314 and into the PTA balloon.

[0243] In some embodiments, the PTA balloon includes a mesh (e.g., a woven mesh), for example, embedded in the polymer of the balloon. When a balloon without such a mesh is punctured, the balloon material may rupture and cause an embolus (e.g., a piece of balloon floating downstream). The mesh can help limit tearing of the balloon material, which can inhibit or prevent the balloon material from causing an embolus.

[0244] In some embodiments, two PTA balloons spaced longitudinally along the axis of the catheter can be used in the target vein, and the needle catheter can target one of the PTA balloons. After piercing one of the PTA balloons by traversing the needle 314, the contrast in the well between the PTA balloons can be released because the pierced balloon no longer acts as a dam for the contrast. The release of the contrast can be monitored using fluoroscopy. The PTA balloons can be on the same catheter or on different catheters.

[0245] In some embodiments, two PTA balloons spaced longitudinally along the axis of the catheter can be used in the target vein, and the needle catheter can target the space or cavity between the PTA balloons. After piercing the cavity by traversing the needle 314, the contrast in the cavity can be disturbed. The interference of the contrast can be monitored using fluoroscopy. The PTA balloon can be on the same catheter or on different catheters.

[0246] In some embodiments in which the PTA balloon is used in combination with an ultrasound target in a target vein, the PTA balloon catheter includes a PTA balloon and an ultrasound receiving transducer (e.g., omnidirectional). In some such embodiments, the transmitting catheter 310 can target the PTA balloon and / or can target the ultrasound receiving transducer under fluoroscopy, as described herein. The traversing needle 314 can pierce the PTA balloon, and the pressure reduction of the PTA balloon can confirm the proper alignment of the traversing needle 314. The PTA balloon can increase the diameter of the vein, creating a larger target for the traversing needle 314, making it easier to enter the vein 300 using the traversing needle 314. The guidewire 316 can be advanced through the traversing needle 314 and into the PTA balloon.

[0247] In some embodiments, a LeMaitre device (e.g., UnBalloon TM A Non-Occlusive Modeling Catheter (available from LeMaitre Vascular of Burlington, Massachusetts) can be used in a target vein. In some embodiments, the LeMaitre device can increase the diameter of the vein. A larger vein diameter can create a larger target for the traversing needle 314, making it easier to enter the vein 300 using the traversing 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 (e.g., including a radiopaque material visible under fluoroscopy) for the traversing needle 314. The mesh of the LeMaitre device can be radially expanded by distally advancing the proximal portion of the mesh and / or proximally retracting the distal portion of the mesh (e.g., pushing the ends together like an umbrella) and / or by making the mesh self-expanding (e.g., in embodiments where at least some components of the mesh include shape memory materials). In some embodiments, the LeMaitre device can grip the traversing wire to maintain the traversing wire in the target vein as the LeMaitre device is approximated.

[0248] In some embodiments, the launch catheter 310 may include a first magnet having a first polarity and the target catheter 320 may include a second magnet having a second polarity. When the magnets are close enough so that the magnetic force moves one or both of the catheters 310, 320, the traversing needle 314 may be advanced to establish a fistula between the artery 300 and the vein 302. In some embodiments, the first magnet may be aligned circumferentially with the traversing needle 314, and / or the launch catheter 310 may be magnetically shielded to provide rotational alignment. In some embodiments, the second magnet may be relatively thin longitudinally to provide longitudinal alignment. In some embodiments, the traversing needle 314 and / or the guide wire 316 may be magnetically pulled from the artery 300 to the vein 302, or vice versa. Some systems may include both ultrasound guidance and magnetic guidance. For example, ultrasound guidance may be used for initial alignment and magnetic guidance may be used for precise alignment.

[0249] Refer again Figures 20A-20H , the prosthesis delivery system 330 carrying the prosthesis 340 is advanced over the guide wire 316 through the interstitial space between the artery 300 and the vein 300, and then enters the vein 300, as shown in FIG. Fig.20F In some embodiments, a separate PTA balloon catheter (e.g., approximately 2 mm) can be advanced over the guidewire 316 to pre-enlarge the fistula between the artery 300 and the vein 302, and then the prosthesis delivery system 330 is introduced. The use of a PTA balloon catheter can depend on, for example, the radial strength of the prosthesis 340.

[0250] The prosthesis 340 is activated by, for example, operating the trigger handle 194 ( Fig.17 ) is deployed from the prosthesis delivery system 330. In some embodiments, for example, if the prosthesis 340 fails to expand and / or advance, the prosthesis delivery system 330 can be removed and a PTA catheter (e.g., approximately 2 mm) can be advanced over the guidewire 316 to attempt to dilate or further dilate the fistula between the artery 300 and the vein 302. Deployment of the prosthesis 340 can then be reattempted (e.g., by self-expansion, balloon expansion, etc.). In some embodiments, deployment of the prosthesis 340 can remodel the vessel, such as expanding the diameter of the vessel by at least about 10%, at least about 20%, at least about 30%, or more, between about 0% and about 10%, between about 0% and about 20%, between about 0% and about 30%, or more. In embodiments where the prosthesis 340 is self-expanding, the degree of modification can change over time, such as the prosthesis 340 expanding when the vessel dilates or the prosthesis 340 contracting when the vessel contracts.

[0251] Once the prosthesis 340 is deployed, as Figure 20GAs shown in , the fistula can be enlarged using a PTA catheter. The diameter of the PTA catheter (e.g., about 3 mm to about 6 mm) can be selected based at least in part on: the diameter of the artery 300, the diameter of the vein 302, the composition of the interstitial tissue, the characteristics of the prosthesis 340, combinations thereof, and the like. In some embodiments, the prosthesis delivery system 330 may include a PTA balloon catheter (e.g., the proximal or distal end of the prosthesis 340), which may be used for one, several, or all of the optional PTA balloon catheter techniques described herein. In embodiments in which the prosthesis includes a conical portion, the PTA balloon may include a conical portion. Once the prosthesis 340 is in place, the prosthesis delivery system 330 can be removed, such as Fig. 20H An AV fistula is thus formed between the artery 300 and the vein 302. Confirmation of the placement of the various catheters 310, 320, 330 and the prosthesis 340 can be confirmed under fluoroscopy using contrast injected throughout part or all of the procedure.

[0252] In some embodiments, a marker (e.g., a clip, a lancet, scissors, a pencil, etc.) can be applied (e.g., adhered, placed on, etc.) to the skin to approximately mark the location of the fistula formed between the artery 300 and the vein 302 by the traversing needle 314, and then the prosthesis 340 is deployed. In embodiments where the user uses a sphygmomanometer inflated on the fistula to avoid bleeding, the lack of blood flow can make visualization or even estimation of the fistula site difficult, and the marker can provide such identification. In embodiments where the sending and receiving catheters are removed after the fistula is formed, the traversing point can be difficult for the user to feel or determine, and the marker can provide such identification. If the fistula is to be enlarged, the midpoint of the enlargement balloon can preferably be aligned with the midpoint of the fistula (e.g., to increase or maximize the hole through the interstitial space). In some embodiments, the marker can be visualized under fluoroscopy (e.g., including radiopaque materials) to allow the user to see or remember the location of the fistula under fluoroscopy, and then the prosthesis 340 is deployed.

[0253] Once the prosthesis 340 is in place, an obstacle to blood flow through the vein 302 and into the foot is the valve in the vein. Maneuvering a guidewire through the venous valve can be challenging, for example because the pressure from the artery may not be sufficient to stretch the vein and make the valve incompetent. Applicants have discovered that the venous valve distal to the AV fistula can be disabled or rendered incompetent using one or more of a number of techniques such as a PTA catheter, stent, and valvulotome, as described in further detail below. Disabling the venous valve can allow blood to flow from the femoral artery via retrograde perfusion, retrograde in the vein 302, and retrograde in the vein to the venules and capillaries distal to the venous circulation of the foot to provide oxygenated blood to the foot of a CLI patient.

[0254] In some embodiments, a high pressure PTA balloon catheter can be used to regurgitate venous valves (eg, when inflated to greater than about 10 atm (about 1,013 kPa)).

[0255] In some embodiments, one or more stents may be placed across one or more venous valves to render those valves incompetent. For example, such stents should have sufficient radial force to keep the valves open.

[0256] In some in situ bypass procedures, the saphenous vein is attached to an artery in the thigh and another artery in the calf, bypassing any blockages in the arteries. In some such procedures, the vein is not stripped from the patient, flipped longitudinally, and used as a prosthesis, but is left in place so that blood flow is retrograde (to the valves of the vein). A standard valvulotomy can be placed into the saphenous vein from below and pushed to the top in a collapsed state, opened, and then pulled back in an open state, cutting the vein valve along the way. The cutting surface of this valvulotomy faces backwards so that it cuts during retraction during these procedures. Fig.23A is a schematic perspective view of an example embodiment of a valvulotome 400 that may be used with such a procedure, including a proximally facing blade 402 .

[0257] In some embodiments of the methods described herein, access distal to the venous valve is not accessible, making it impossible to pull the valvulotome backward, but possible to push the reverse valvulotome forward as described herein. Fig. 23B 4 is a schematic perspective view of an example embodiment of a valvulotomy tool 410 that can be used with such a procedure. The reverse valvulotomy tool 410 includes one or more blades 412 facing forward or distally (e.g., 2-5 blades (e.g., 3 blades)) so that the valve can be cut when the reverse valvulotomy tool 410 is advanced distally. At least because retrograde access to the vein to be incapacitated was not previously considered a problem, there is no a priori motivation to reverse the direction of the blades of the valvulotomy tool to form the reverse valvulotomy tool 410 as described herein. The reverse valvulotomy tool 410 can be advanced on a guide wire 414, which can be manipulated into the vein for venous valve insufficiency. After a fistula is formed between an artery and a vein as described herein, the fluid flow in the vein is in a direction opposite to the natural or normal or preoperative direction of the fluid flow in the vein, so that the reverse valvulotomy tool 410 is pushed in a direction opposite to the natural fluid flow but in the direction of the fluid flow after the fistula.

[0258] Other systems and methods can also be used to ablate valvular insufficiency in a vein (e.g., cutting balloons, percutaneous atherectomy, laser ablation, ultrasonic ablation, heating, radiofrequency (RF) ablation, catheters with invasive or non-atraumatic tips that are advanced and / or retracted (e.g., guide sheaths), combinations thereof, and the like).

[0259] It can also be challenging to traverse venous valves in a retrograde manner prior to rendering such valvular regurgitation ineffective. Fig.24 420. It is a schematic perspective view of an example embodiment of a LeMaitre device 420, which can be used to radially expand veins and thus expand their valves. The LeMaitre device 420 includes expandable elliptical or elongated leaflets 422, such as self-expanding nitinol mesh. In some embodiments, a PTA balloon catheter can be used to radially expand veins and thus radially expand their valves. In some embodiments, applying a tourniquet to a leg can radially expand veins and thus radially expand their valves. After radial expansion, a guide wire can be advanced through the stretched valve (one or more) (e.g., by an expansion device such as the LeMaitre device) and a catheter (e.g., PTA, stent delivery, percutaneous atherectomy, etc.) or other online (over-the-wire) devices can be advanced on the guide wire.

[0260] Although some example embodiments have been disclosed in detail herein, this has been done by way of example and for illustrative purposes only. The above-described embodiments are not intended to be limiting with respect to the scope of the appended claims. The inventors contemplate that various substitutions, changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention as defined in the claims.

[0261] While the devices described herein can be used in applications where the fluid flowing through the device is a liquid such as blood, the devices can also or alternatively be used in applications such as tracheal or bronchial surgery where the fluid is a gas such as air. In some embodiments, the fluid can contain solid matter, such as emboli or, in gastric surgery, food particles.

[0262] Although the present invention is susceptible to various variations and alternative forms, specific examples thereof have been shown in the drawings and described in detail herein. However, it should be understood that the present invention is not limited to the specific forms or methods disclosed, but, on the contrary, the present invention covers all variations, equivalents and alternatives falling within the spirit and scope of the various embodiments described and the appended claims. Any method disclosed herein does not have to be performed in the order described. The methods disclosed herein include certain actions taken by the practitioner; however, they may also include any third-party instructions for these actions, whether explicit or implicit. For example, actions such as "causing valvular insufficiency in the first blood vessel" include "instructions to cause valvular insufficiency in the first blood vessel". The ranges disclosed herein also include any and all overlaps, sub-ranges and combinations thereof. Language such as "until", "at least", "greater than", "less than", "between", etc. include the numbers described. Terms such as "about" or "approximately" before the number include the numbers described. For example, "about 10mm" includes "10mm". Terms or phrases described by terms such as "substantially" before the term or phrase include. For example, "substantially parallel" includes "parallel".

[0263] The claims set forth several embodiments of the invention. These non-limiting claims identify certain permutations of the combination of features disclosed herein, although other permutations of the combination of features are also within the scope of the invention.

Claims

1. A device for changing a blood flow path, the device comprising: A support structure comprising: a first end portion configured to be anchored in a first passage, the first end portion comprising a first diameter; a second end portion configured to be anchored in a second passageway different from the first passageway, the second end portion comprising a second diameter different from the first diameter; an intermediate portion between the first end portion and the second end portion, wherein the intermediate portion is frustoconical; a graft material bonded to at least the middle portion, wherein the graft material is configured to inhibit perfusion through the side walls of the device, and a tube connected to the support structure, the tube at least partially forming a lumen configured to divert blood flow from the first channel to the second channel, Wherein the porosity of at least one of the first end portion, the second end portion or the middle portion is one or more of: between 5% and 95%, between 5% and 50%, between 5% and 25%, between 5% and 10%, between 10% and 50%, between 10% and 25%, between 25% and 50%, between 50% and 95%, between 50% and 75%, between 50% and 60%, between 60% and 95%, between 75% and 90%, or between 60% and 75%.

2. The apparatus of claim 1, wherein the first end is frustoconical.

3. The apparatus of claim 2, wherein the second end is frustoconical.

4. The apparatus of claim 1, wherein the second end is frustoconical.

5. The apparatus of claim 1, wherein at least one of the first end or the second end is cylindrical.

6. The device according to any one of claims 1 to 5, wherein the support structure is self-expanding.

7. The device according to any one of claims 1 to 5, wherein the support structure is balloon expandable.

8. The device according to any one of claims 1 to 5, wherein the first channel is an artery.

9. The device of claim 8, wherein the second channel is a vein.

10. The device according to any one of claims 1 to 5, wherein the second channel is a vein.

11. The apparatus of any one of claims 1 to 5, wherein the widest diameter of the first end is between 4 mm and 10 mm.

12. The apparatus of any one of claims 1 to 5, wherein the second end of the second end portion has a second distal diameter of between 2 mm and 8 mm.

13. The apparatus of any one of claims 1 to 5, wherein the widest diameter of the first end portion is between 4 mm and 10 mm, and wherein the second terminal diameter of the second end portion is between 2 mm and 8 mm.

14. Apparatus according to any one of claims 1 to 5, wherein the first end has a length of between 20 mm and 50 mm.

15. The apparatus of any one of claims 1 to 5, wherein the second end has a length of between 10 mm and 25 mm.

16. The apparatus of any one of claims 1 to 5, wherein the first end has a length of between 20 mm and 50 mm, and wherein the second end has a length of between 10 mm and 25 mm.

17. Apparatus according to any one of claims 1 to 5, wherein the first end portion and the intermediate portion have a total length of between 20 mm and 50 mm.

18. The apparatus of any one of claims 1 to 5, wherein the angle of the taper of the first end portion and the angle of the taper of the intermediate portion are between 0.02 radians and 0.03 radians.

19. The device according to claim 1, wherein the first end is frustoconical, and Wherein the second end is cylindrical.

20. The device according to claim 1, wherein the first end portion comprises a strut or filament having a first thickness, and Wherein the second end comprises struts or filaments having a second thickness different from the first thickness.

21. The apparatus of claim 20, wherein one or more of the first thickness or the second thickness is greater than 0.006 inches.

22. The apparatus of claim 20, wherein one or more of the first thickness or the second thickness is less than 0.003 inches.

23. The apparatus of claim 20, wherein one or more of the first thickness or the second thickness is between 0.003 inches and 0.006 inches.

24. An implantable device for treating vascular occlusion, the device comprising: a first end having a frustoconical shape, the first end comprising a narrowest diameter and a widest diameter, wherein the first end is configured to reside at least partially in the first passage; a second end portion having a second distal diameter, the second distal diameter being smaller than the widest diameter, the second end portion being cylindrical, wherein the second end portion is configured to reside at least partially in a second passageway, one of the first passageway and the second passageway comprising the vascular occlusion; an intermediate portion between the first end and the second end, the intermediate portion tapering between a narrowest diameter of the first end and a second terminal diameter of the second end, wherein the intermediate portion is configured to reside at least partially in a passage between the first passage and the second passage; and a graft material bonded to at least the middle portion, wherein the graft material is configured to inhibit perfusion through the side walls of the device, wherein the widest diameter of the first end portion is between 4 mm and 10 mm, wherein the first end has a length between 20 mm and 50 mm, wherein the second end diameter of the second end portion is between 2 mm and 8 mm, and Wherein the second end has a length between 10 mm and 25 mm.

25. An implantable device for treating vascular occlusion, the device comprising: a first end having a frustoconical shape, the first end comprising a narrowest diameter and a widest diameter, wherein the first end is configured to reside at least partially in the first passage; a second end portion having a second distal diameter, the second distal diameter being smaller than the widest diameter, the second end portion being cylindrical, wherein the second end portion is configured to reside at least partially in a second passageway, one of the first passageway and the second passageway comprising the vascular occlusion; an intermediate portion between the first end and the second end, the intermediate portion tapering between a narrowest diameter of the first end and a second terminal diameter of the second end, wherein the intermediate portion is configured to reside at least partially in a passage between the first passage and the second passage; and A graft material is bonded to at least the middle portion, wherein the graft material is configured to inhibit perfusion through a side wall of the device, wherein the first end portion and the middle portion have a total length of between 20 mm and 50 mm.

26. The apparatus of claim 25, wherein the widest diameter of the first end portion is between 4 mm and 10 mm, and wherein the second end diameter of the second end portion is between 2 mm and 8 mm.

27. An implantable device for treating vascular occlusion, the device comprising: a first end having a frustoconical shape, the first end comprising a narrowest diameter and a widest diameter, wherein the first end is configured to reside at least partially in the first passage; a second end portion having a second distal diameter, the second distal diameter being smaller than the widest diameter, the second end portion being cylindrical, wherein the second end portion is configured to reside at least partially in a second passageway, one of the first passageway and the second passageway comprising the vascular occlusion; an intermediate portion between the first end and the second end, the intermediate portion tapering between a narrowest diameter of the first end and a second terminal diameter of the second end, wherein the intermediate portion is configured to reside at least partially in a passage between the first passage and the second passage; and A graft material is bonded to at least the middle portion, wherein the graft material is configured to inhibit perfusion through a sidewall of the device, wherein the angle of the taper of the first end and the angle of the taper of the middle portion are between 0.02 radians and 0.03 radians.

28. The apparatus of any one of claims 24 to 27, wherein at least one of the first end and the second end comprises a shape memory material.

29. The apparatus of any one of claims 24 to 27, wherein at least one of the first end and the second end materials comprises Nitinol.

30. The apparatus of any one of claims 24 to 27, wherein the intermediate portion comprises nitinol.

31. The apparatus of any one of claims 24 to 27, wherein the first end comprises a cutting strut and the second end comprises a cutting strut.

32. The apparatus of any one of claims 24 to 27, wherein at least some of the graft material is outside of the middle portion, at least some of the graft material is inside of the middle portion, or at least some of the graft material is embedded within the middle portion.

33. The apparatus of any one of claims 24 to 27, wherein the first end is longer than the second end.

34. The apparatus of any one of claims 24 to 27, wherein the second channel comprises the vessel occlusion.

35. The apparatus of claim 34, wherein the second channel comprises an artery, and wherein the first channel comprises a vein.

36. The apparatus of any one of claims 24 to 27, wherein the second channel comprises an artery.

37. The apparatus of any one of claims 24 to 27, wherein the first channel comprises a vein.

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