Endovascular implants, devices, and methods for percutaneous arteriovenous fistula formation

Abstract

Various systems, devices, and methods are disclosed for an intravascular implant and its accurate placement. The implant includes a proximal implant segment, a distal implant segment, a connecting strut for connecting the proximal implant segment to the distal implant segment, and a side opening between the proximal implant segment and the distal implant segment. The implant can be used for forming an arteriovenous fistula or for placing the proximal and distal implant segments within a blood vessel to be connected to connect a blood vessel in the body to another blood vessel. The implant may include one or more anchors for fixing the implant in place with respect to the blood vessel in the body to be connected. The implant can also include a strut or ring continuous with the distal edge of the proximal implant segment. Methods for accurately percutaneously placing the implant of the present disclosure and devices for percutaneous delivery are also disclosed.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority based on U.S. Provisional Patent Application No. 63 / 340,834, filed on May 11, 2022, and U.S. Provisional Patent Application No. 63 / 497,945, filed on April 24, 2023, and the entire contents thereof are incorporated herein by reference for all purposes.

[0002] Some aspects herein relate to an intravascular implant system, method, and apparatus that provide accurate percutaneous placement into a blood vessel, including the formation of an arteriovenous (AV) fistula in the arm for dialysis access.

Background Art

[0003] Many interventional intravascular procedures that require accurate placement of implants, such as intravascular stents, filters, covered stents (stent - grafts), etc., have been developed and implemented. These intravascular procedures are for treating vascular occlusive diseases, aneurysm diseases, and other abnormalities of the vascular system. They are also used for treating both portal hypertension and systemic hypertension by short - circuiting blood flow from the high - pressure arterial system to the low - pressure venous system. Another treatment that can be performed by intravascular procedures is the formation of an arteriovenous fistula, which is done by installing a vascular implant between a vein and an artery to form a vascular access for hemodialysis.

[0004] Such intravascular implant procedures generally rely on expensive X - ray imaging methods such as fluoroscopy before the deployment and delivery of the implant, and the excellent skills of the operator to accurately position the catheter - based delivery system. Such techniques require a special treatment room, wearing of lead - based protective gear, and injection of toxic contrast agents into the patient, which may cause excessive stress to the renal system. In percutaneous ultrasound imaging, it does not provide the image resolution necessary for accurate positioning during these procedures. Improvements in implants and procedures are desired.

[0005] In particular, hemodialysis can benefit from improved implants and methods. Hemodialysis is a life-saving treatment for kidney failure that filters a patient's blood outside the body using a machine called a dialyzer. Vascular access is necessary to perform blood withdrawal and return during the procedure. During hemodialysis, the patient's blood flows from one access point (e.g., through a needle inserted into the access vein) through a tube to the dialyzer, where waste products and excess water are filtered, and then returns through another tube to another access point (e.g., through another needle inserted into the same or a different access vein) and back to the patient. Vascular access allows a large volume of blood to flow continuously during hemodialysis treatment, enabling the maximum amount of blood to be filtered during the procedure. Vascular access generally consists of two types: a long-term type including arteriovenous fistulas and arteriovenous grafts, and a short-term type including venous catheters.

[0006] An arteriovenous (AV) fistula used in hemodialysis is generally a short-circuit site formed between an artery and a vein by a vascular surgeon. In the formation of an AV fistula, the vascular surgeon short-circuits the patient's artery to the patient's vein. The installation of an AV fistula is generally in the forearm or upper arm, and it is desirable to short-circuit an artery (located near the deep vein inside the muscle) to a superficial vein (located near the surface above / outside the muscle) for easy access. Due to the AV fistula, the vein is exposed to higher blood pressure and blood flow, causing the vein to grow larger and stronger. The expansion of the vein makes the goal of vascular access easier and more reliable, the increased blood flow enables access to a single vein, allowing more blood to be filtered, and the improved strength not only prevents vein collapse during the procedure but also enables the vein to handle repeated needle insertions for continuous treatment.

[0007] An AV graft for use in hemodialysis is generally a loop-shaped plastic tube that is implanted in a patient's body (e.g., does not protrude from the skin), shunts an artery and a vein, and is surgically placed by a vascular surgeon. In contrast to a patient's vein being used as a vascular access during hemodialysis, an AV graft is used for access to the vascular system (e.g., an access needle is inserted into the graft tube instead of the patient's vein).

[0008] A venous catheter for use in hemodialysis is a tube inserted into a vein in a patient's neck, chest, or leg near the groin. This method has a high risk of sepsis and death, so it is usually only used for short-term hemodialysis. After the tube exits the body, it branches into two, enabling the two types of connections typical of hemodialysis treatment (e.g., blood drainage and return of filtered blood). If a patient's condition progresses rapidly, there may not be time to place an AV fistula or AV graft before starting hemodialysis. This is because both typically require a growth / maturation period of 2 to 3 months before they can be used for hemodialysis. In this case, a venous catheter may be needed until a more permanent vascular access is established.

[0009] Among the methods of creating access for hemodialysis, an AV fistula is preferred over the other types described above because it provides the required blood flow for dialysis, is long-lasting, and has a low incidence of infection and thrombosis. Although it is suitable, the current method of creating an AV fistula has drawbacks. One of the main drawbacks is that a vascular surgeon must surgically create the AV fistula, which requires appropriate personnel, equipment, and infrastructure for this purpose.

[0010] More recent methods of AV fistula formation, such as catheter electrocautery, may allow for a more minimally invasive approach, but do not overcome all of the drawbacks of conventional surgical methods and may introduce new drawbacks. That is, in the catheter electrocautery approach, due to the anatomical requirement of forming an AV fistula between adjacent blood vessels, the AV fistula is not formed directly between the artery and the type of superficial vein desirable as the access vein for hemodialysis, but rather between the artery and the deep vein. The perforating vein extends between and connects the deep vein and the superficial vein, but the deep vein also has multiple branch points at anatomical sites frequently used for the formation of AV fistulas. Thus, an AV fistula formed by the catheter electrocautery approach can disperse the blood flow from the artery into multiple venous branches and direct only a portion to the desired superficial vein, which may not induce the necessary anatomical changes in the superficial vein as described above or may not provide sufficient blood flow for hemodialysis treatment procedures. Secondary procedures such as ligating or embolizing the connected branch veins may be required to direct blood from the artery to the desired superficial vein. In this case, securing a long-term vascular access for the patient is delayed, an extension of access by a venous catheter is required, and the patient is exposed to an increased risk associated with the access method. There remains a need to improve methods, systems, and devices for forming AV fistulas for hemodialysis. SUMMARY OF THE INVENTION

[0011] The embodiments disclosed herein each have several aspects, and no single one of them alone bears the desirable attributes of the present disclosure. Without limiting the scope of the present disclosure, the more prominent features of the present disclosure are briefly described below. Upon consideration of this discussion, and particularly upon reading the [Detailed Description] section, it will be understood how the features of the embodiments described herein provide advantages over existing systems, devices, and methods.

[0012] In some embodiments, an implant configured to be percutaneously delivered to a patient's arm for arteriovenous fistula formation is disclosed. The implant includes a proximal implant segment comprising a proximal end, a distal end, and an axis extending therethrough, and a distal implant segment connected to the proximal implant segment, the distal implant segment comprising a proximal end, a distal end, and an axis extending therethrough, and a side opening between the distal end of the proximal implant segment and the proximal end of the distal implant segment, and the proximal implant segment is configured to bend or curve at least 90 degrees relative to the distal implant segment in a direction away from the side opening.

[0013] In the above implant or in other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the side opening is configured to allow blood to flow through the side opening in (i) a first direction along the proximal implant segment from the distal end of the proximal implant segment towards the proximal end of the proximal implant segment and (ii) a second direction along the distal implant segment from the proximal end of the distal implant segment towards the distal end of the distal implant segment. In some embodiments, the proximal implant segment is bendable or curvable relative to the distal implant segment by at least 180 degrees in a direction away from the side opening. In some embodiments, the proximal implant segment comprises a series of strut rows arranged substantially circumferentially around the axis of the proximal implant segment, and the series of strut rows of the proximal implant segment are interconnected by one or more axially extending struts arranged substantially along the axis of the proximal implant segment. In some embodiments, adjacent strut rows of the proximal implant segment are connected by only one axially extending strut. In some embodiments, each strut row is composed of a row of wavy struts. In some embodiments, the distal implant segment comprises a series of strut rows arranged at least partially circumferentially around the axis of the distal implant segment, and the series of strut rows of the distal implant segment are interconnected by one or more axially extending struts arranged substantially along the axis of the distal implant segment. In some embodiments, the series of strut rows of the distal implant segment are interconnected by at least one more axially extending strut than the series of strut rows of the proximal implant segment to provide greater flexibility to the distal implant segment compared to the proximal implant segment. In some embodiments, most or all of the one or more axially extending struts of the proximal implant segment are located on the side of the proximal implant segment that aligns with the location of the side opening.In some embodiments, the proximal implant segment has greater flexibility than the distal implant segment. In some embodiments, the proximal implant segment comprises a tubular body having a fluid passage lumen extending between its proximal end and its distal end. In some embodiments, the proximal implant segment is linear. In some embodiments, the distal implant segment comprises at least a partially tubular body extending between its proximal end and its distal end. In some embodiments, the distal implant segment comprises a tubular body having a fluid passage lumen extending between its proximal end and its distal end. In some embodiments, the distal implant segment is linear. In some embodiments, the proximal implant segment and the distal implant segment comprise an expandable body, and the proximal implant segment is oriented at an angle relative to the distal implant segment when the proximal and distal implant segments are fully expanded in a stationary configuration. In some embodiments, the axial length of the proximal implant segment is greater than the axial length of the distal implant segment. In some embodiments, the distal end of the proximal implant segment includes an anastomotic ring. In some embodiments, one or both of the proximal implant segment and the distal implant segment comprise one or more anchors configured to secure one or both of the segments to the wall of a vein or artery. In some embodiments, one or both of the proximal implant segment and the distal implant segment are coated with a graft material. In some embodiments, the implant is configured to be folded into a collapsed configuration for percutaneous delivery into the patient's arm and to expand from the collapsed configuration to an expanded configuration for implantation between the patient's vein and artery. In some embodiments, the proximal implant segment and the distal implant segment are formed as a single unitary body. In some embodiments, the proximal implant segment and the distal implant segment comprise a metal frame.In some embodiments, the proximal implant segment and the distal implant segment are formed from a single laser cut hypotube. In some embodiments, the implant further comprises one or more axially extending struts that connect the distal end of the proximal implant segment and the proximal end of the distal implant segment.

[0014] In some embodiments, a method of forming an arteriovenous fistula in a patient is disclosed. This includes delivering an endoluminal implant in a folded configuration within a sheath that constrains the endoluminal implant at its distal end to the patient, the endoluminal implant comprising a proximal implant segment and a distal implant segment, the proximal implant segment being coupled to the distal implant segment, a portion of the distal end of the sheath being delivered to the patient within the proximal cavity of the nose cone, and the nose cone comprising an angled proximal end including a most proximal tip spaced radially outward from the inner diameter of the proximal cavity, the delivery step; extending the endoluminal implant within the sheath between the vein and the artery, the proximal implant segment extending at least partially through one of the vein and the artery, and the distal implant segment and the nose cone being disposed within the other of the vein and the artery distal to the proximal implant segment, the extending step; pulling the nose cone and the sheath proximally to engage the most proximal tip of the nose cone with the wall of the vein or artery in which the distal implant segment is disposed; pulling the sheath proximally relative to the nose cone to radially expand the proximal implant segment and engage the proximal implant segment with the wall of the vein or artery in which the proximal implant segment extends; advancing the nose cone distally relative to the distal implant segment to radially expand the distal implant segment and engage the distal implant segment with the wall of the vein or artery in which the distal implant segment is disposed.

[0015] In the above method or in other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the proximal tip is spaced radially outwardly from the diameter of the virtual projection of the inner diameter of the proximal cavity to form a radial gap between the proximal tip and the virtual projection of the inner diameter, whereby the proximal tip can engage the wall of the vein or artery in which the distal implant segment is disposed. In some embodiments, the proximal end of the nose cone includes a first surface that extends proximally and radially outwardly from the inner diameter of the proximal cavity to the proximal tip in a longitudinal cross-section, and a second surface that extends distally and radially outwardly from the proximal tip to the outer diameter of the nose cone. In some embodiments, the proximal implant segment expands radially to engage the wall of the vein, and the distal implant segment expands radially to engage the wall of the artery. In some embodiments, the intraluminal implant includes a side opening between the distal end of the proximal implant segment and the proximal end of the distal implant segment, whereby, after the proximal implant segment expands radially to engage the wall of the vein and the distal implant segment expands radially to engage the wall of the artery, the blood flowing through the artery enters the side opening and (i) continues to flow through the artery through the proximal end of the distal implant segment and the distal end of the distal implant segment, and (ii) exits from the proximal end of the proximal implant segment through the distal end of the proximal implant segment and flows into the vein. In some embodiments, the method further includes applying a reaction force to the patient when retracting the sheath proximally relative to the nose cone to assist in maintaining the engagement of the proximal tip of the nose cone with the wall of the vein or artery while releasing the proximal implant segment from the sheath. In some embodiments, the reaction force is applied by a reaction force mechanism configured to apply a reaction force to the patient's skin.

[0016] In some embodiments, an intraluminal implant is disclosed that comprises one or more features described in the summary of the invention above and / or further summarized and / or described herein.

[0017] In some embodiments, a delivery system is disclosed for delivering an endoluminal implant having one or more features described in the above Summary of the Invention and / or further summarized and / or described herein.

[0018] In some embodiments, a method is disclosed for delivering an endoluminal implant having one or more features described in the above Summary of the Invention and / or further summarized and / or described herein.

[0019] Any embodiment summarized above or further described in the Detailed Description of the Invention can further include or alternatively include the features of the systems, devices, and methods summarized below.

[0020] In some embodiments, a system for forming an arteriovenous fistula in a patient's arm is disclosed. The system includes an intravascular delivery device configured to access within the patient's arm, the intravascular delivery device being configured to advance into a superficial vein, a perforating vein, a deep vein, and an artery adjacent to the deep vein, and an intravascular implant configured such that the intravascular delivery device carries the intravascular implant to the patient's arm in a radially compressed configuration. The intravascular implant includes a proximal implant segment including a proximal end and a distal end, the proximal implant segment being releasable from the intravascular delivery device such that the proximal implant segment deforms from a radially compressed configuration to a radially expanded configuration in which the proximal implant segment extends through the perforating vein and the deep vein and the proximal end of the proximal implant segment is positioned within the perforating vein, and a distal implant segment connected to the proximal implant segment, the distal implant segment being releasable from the intravascular delivery device such that the distal implant segment deforms from a radially compressed configuration to a radially expanded configuration in which the distal implant segment is positioned within the artery, and the distal end of the proximal implant segment is configured to have an angle with respect to the axis of the distal implant segment. The system is configured such that when the proximal implant segment is in a radially expanded configuration extending through the perforating vein and the deep vein and the distal implant segment is in a radially expanded configuration within the artery, the proximal implant segment is configured to direct flow from the artery towards the superficial vein.

[0021] In the above-described system, or in other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the distal implant segment is configured to be fixed to the wall of the artery. In some embodiments, the distal implant segment includes a tubular body configured to provide radial support to the artery. In some embodiments, the proximal implant segment includes a tubular body configured to engage radially with the wall of the perforating vein. In some embodiments, the distal end of the proximal implant segment is configured to be fixed to the wall of the artery. In some embodiments, the distal end of the proximal implant segment includes an anchor configured to fix to the wall of the artery. In some embodiments, one or both of the proximal implant segment and the distal implant segment are coated with a graft material. In some embodiments, when the implant includes a side opening between the distal end of the proximal implant segment and the proximal end of the distal implant segment, the proximal implant segment is in a radially expanded configuration extending through the perforating vein and the deep vein, and the distal implant segment is in a radially expanded configuration within the artery, the blood flowing through the artery flows into the side opening and (i) flows through the proximal end of the distal implant segment and exits from the distal end of the distal implant segment, and (ii) flows through the distal end of the proximal implant segment and exits from the proximal end of the proximal implant segment. In some embodiments, the distal end of the proximal implant segment includes an anastomosis ring. In some embodiments, the distal end of the proximal implant segment is configured to have an angle of about 0 degrees to about 90 degrees with respect to the axis of the distal implant segment. In some embodiments, the distal implant segment is connected to the proximal implant segment by at least one connecting strut. In some embodiments, the delivery device includes a sheath configured to constrain the intraluminal implant in a radially compressed configuration within its distal end.In some embodiments, the delivery device further includes a nose cone that is advanceable within an artery, and the distal end of the sheath is configured to be inserted into the cavity of the nose cone to advance the nose cone within the artery. In some embodiments, the nose cone includes a proximal tapered end configured to engage the proximal wall of the artery. In some embodiments, after the distal end of the sheath has advanced into the artery with the nose cone, the sheath is retractable proximally relative to the nose cone to expand the proximal implant segment within the deep vein and the perforating vein, and the nose cone is configured to be advanceable distally relative to the distal implant segment to expand the distal implant segment within the artery after the proximal implant segment has been expanded within the deep vein and the perforating vein. In some embodiments, after the distal implant segment has been expanded within the artery, the sheath is advanceable to engage the nose cone through the expanded proximal implant segment and the expanded distal implant segment, thereby facilitating removal of the nose cone from the artery together with the sheath. In some embodiments, the delivery device further includes a guide wire shaft configured to advance over a guide wire, and the nose cone is fixed to the guide wire shaft.

[0022] In some embodiments, a method of forming an arteriovenous fistula in a patient's arm is disclosed. This includes delivering an endoluminal implant in a folded configuration into the patient's body, the endoluminal implant including a proximal implant segment and a distal implant segment, the proximal implant segment being connected to the distal implant segment; a delivery step; extending the endoluminal implant between a deep vein and an artery adjacent to the deep vein, the proximal implant segment extending through a perforating vein and the deep vein, and the distal implant segment being positioned within the artery; an extending step; radially expanding the proximal implant segment to engage the proximal implant segment with the wall of the perforating vein, and radially expanding the distal implant segment to engage the distal implant segment with the wall of the artery to radially support the artery, thereby redirecting blood flowing through the artery from the artery to a superficial vein connected to the perforating vein; a radial expansion step.

[0023] In the above method or in other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the endovascular implant includes a side opening between the distal end of the proximal implant segment and the proximal end of the distal implant segment, whereby after the proximal implant segment expands radially to engage the wall of the perforating vein and the distal implant segment expands radially to engage the wall of the artery, blood flowing through the artery enters the side opening and (i) flows through the proximal end and the distal end of the distal implant segment and continues to flow through the artery, and (ii) exits from the proximal end of the proximal implant segment through the distal end of the proximal implant segment, flows into the perforating vein, and flows into the superficial vein. In some embodiments, the proximal implant segment and the distal implant segment include tubular bodies. In some embodiments, the method further includes fixing the distal end of the proximal implant segment to the wall of the artery. In some embodiments, after the proximal implant segment expands radially to engage the wall of the perforating vein and the distal implant segment expands radially to engage the wall of the artery, the proximal implant segment has an angle with respect to the axis of the distal implant segment. In some embodiments, the proximal implant segment has an angle of about 0 degrees to about 90 degrees with respect to the axis of the distal implant segment. In some embodiments, the endovascular implant is delivered to the patient within a sheath that constrains the endovascular implant at the distal end of the sheath. In some embodiments, the distal end of the sheath is advanced into the artery within the cavity of the nose cone. In some embodiments, by retracting the sheath proximally relative to the nose cone, the proximal implant segment is released from the sheath and expands radially to engage the wall of the perforating vein. In some embodiments, the distal implant segment expands radially to engage the wall of the artery by advancing the nose cone distally relative to the distal implant segment.In some embodiments, the method further includes advancing a sheath distally through a radially expanded proximal implant segment and a radially expanded distal implant segment to engage a nose cone, and retracting proximally the sheath engaged with the nose cone through the radially expanded proximal implant segment and the radially expanded distal implant segment. In some embodiments, the nose cone includes a proximally tapered tip that engages the arterial wall while the sheath retracts proximally to release the proximal implant segment. In some embodiments, after the nose cone advances distally to release the distal implant segment and before retracting proximally the sheath engaged with the nose cone through the radially expanded proximal implant segment and the radially expanded distal implant segment, the nose cone is rotated within the artery.

[0024] In some embodiments, a method of forming an arteriovenous fistula is disclosed. The method includes accessing a superficial vein, advancing an access tool into the superficial vein, through a perforating vein, and into a deep vein, advancing the access tool through the outer wall of the deep vein lumen, an interstitial cavity, or any interstitial cavity, and an artery (also referred to herein as a "deep artery"), advancing a guidewire through the access tool into the artery, withdrawing the access tool over the guidewire, and / or advancing a device (also referred to herein as a "delivery device") over the guidewire such that the distal end of the device is within the artery and a more proximal segment of the device spans the above or any interstitial cavity.

[0025] In the above method or in other embodiments described herein, one or more of the following features may also be provided. In some embodiments, in the present method, advancing an access tool through the lumen wall of a deep vein, an interstitial cavity or any interstitial cavity, and the outer wall of an artery includes actuating a port proximate to the proximal end of the access tool, thereby including extending a sharp needle tip distally from the distal end of the access tool. In some embodiments, actuating the port includes depressing the port and compressing a spring element operably connected to the sharp needle tip. In some embodiments, the method further includes releasing the port, thereby allowing the spring element to recoil and the sharp needle tip to retract proximally toward the distal end of the access tool. In some embodiments, the device or delivery device includes a nose cone. In some embodiments, the nose cone includes a proximal tapered end, a central lumen, a distal tapered end, and a longitudinal axis. In some embodiments, the device or delivery device includes a flexible sheath including a longitudinal axis. In some embodiments, the implant is conveyed within the flexible sheath in a radially compressed configuration. In some embodiments, after advancing the device or delivery device onto a guidewire, the distal end of the flexible sheath is within the central lumen of the nose cone. And when the flexible sheath enters the central lumen of the nose cone from the proximal tapered end of the nose cone, a gap is formed between the proximal tapered end of the nose cone and the sidewall of the flexible sheath. Here, the longitudinal axis of the flexible sheath is not coaxial with the longitudinal axis of the nose cone. In some embodiments, the length of the gap is about 5% to about 50% of the diameter of the proximal tapered end of the nose cone. In some embodiments, no gap is formed and / or is not required between the proximal tapered end of the nose cone and the sidewall of the flexible sheath. In some embodiments, the method further includes pulling the nose cone and the flexible sheath proximally such that the nose cone engages the proximal wall of the artery. In some embodiments, the method further includes pulling the sheath proximally, thereby allowing deformation of the proximal segment of the implant from a radially compressed configuration to a radially expanded configuration.In some embodiments, pulling the sheath proximally releases an anchor that engages the proximal segment of the implant against the proximal wall of the artery. In some embodiments, the distal segment of the implant remains within the nose cone in a radially compressed configuration while the proximal segment of the implant is in a radially expanded configuration. In some embodiments, the method further comprises advancing the nose cone relative to the distal segment of the implant, thereby deforming the distal segment of the implant into a radially expanded configuration. In some embodiments, advancing the nose cone releases an anchor that engages the proximal segment of the implant against the proximal wall of the artery. In some embodiments, pulling the sheath proximally releases an anchor that engages the proximal segment of the implant against the proximal wall of the artery. In some embodiments, the method further comprises advancing the sheath distally through the distal segment of the implant in a radially expanded configuration, thereby engaging the nose cone. In some embodiments, the method further comprises rotating the nose cone about its longitudinal axis. In some embodiments, the method further comprises pulling the nose cone and the flexible sheath proximally from the artery, the above or any interstitial lumen, deep vein, perforating vein, and superficial vein while leaving the implant in place.

[0026] In some embodiments, a method of forming a fistula is disclosed. The method includes advancing an access tool through the luminal wall of a first lumen, the interstitial space, and the outer wall of a second lumen, advancing a guidewire through the access tool and into the second lumen, pulling the access tool on the guidewire, and / or advancing a device (also referred to herein as a “delivery device”) on the guidewire such that the distal end of the device is within the second lumen and a more proximal segment of the device spans the above or any interstitial cavity. The device includes a nose cone having a proximal tapered end, a central lumen, a distal tapered end, and a longitudinal axis, and a flexible sheath having a longitudinal axis. After advancing the device on the guidewire, when the distal end of the flexible sheath is present within the central lumen of the nose cone and the longitudinal axis of the flexible sheath is not coaxial with the longitudinal axis of the nose cone as the flexible sheath enters the central lumen of the nose cone from the proximal tapered end of the nose cone, a gap is formed between the proximal tapered end of the nose cone and the sidewall of the flexible sheath.

[0027] In the above method or in other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the length of the gap is from about 5% to about 50% of the diameter of the proximal tapered end of the nose cone. In some embodiments, the gap is at least partially formed by biasing the nose cone relative to the flexible sheath. In some embodiments, no gap is formed and / or is not required between the proximal tapered end of the nose cone and the sidewall of the flexible sheath. In some embodiments, biasing the nose cone includes actuating at least one pull wire. In some embodiments, the method further includes pulling the nose cone and the flexible sheath proximally such that the nose cone engages the proximal wall of the second lumen. In some embodiments, the implant is delivered in a radially compressed configuration within the flexible sheath. In some embodiments, the method further includes pulling the sheath proximally, thereby enabling the proximal segment of the implant to deform from a radially compressed configuration to a radially expanded configuration. In some embodiments, pulling the sheath proximally releases an anchor that engages the proximal segment of the implant against the proximal wall of the second lumen. In some embodiments, the distal segment of the implant remains within the nose cone in a radially compressed configuration while the proximal segment of the implant is in a radially expanded configuration. In some embodiments, the method further includes advancing the nose cone relative to the distal segment of the implant, thereby deforming the distal segment of the implant to a radially expanded configuration. In some embodiments, advancing the nose cone releases an anchor that engages the proximal segment of the implant against the proximal wall of the second lumen.

[0028] In some embodiments, a catheter delivery system or device is disclosed that includes a nose cone having a proximal tapered end, a central lumen, a distal tapered end, and a longitudinal axis, and a flexible sheath having a longitudinal axis. The device is configured such that the distal end of the flexible sheath is disposed within the central lumen of the nose cone, and when the distal end of the flexible sheath enters the central lumen of the nose cone from the proximal tapered end of the nose cone, a gap is formed between the proximal tapered end of the nose cone and the sidewall of the flexible sheath when the longitudinal axis of the flexible sheath is not coaxial with the longitudinal axis of the nose cone.

[0029] In the above system or device, or in other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the nose cone includes a slit. In some embodiments, the slit is at the proximal tapered end of the nose cone. In some embodiments, no gap is formed between the proximal tapered end of the nose cone and the sidewall of the flexible sheath and / or is not required.

[0030] In some embodiments, an endoluminal implant is disclosed. The endoluminal implant includes a proximal implant segment, a distal implant segment, and at least one axially directed connecting strut connecting the proximal implant segment and the distal implant segment. The proximal implant segment and the distal implant segment each include a flow lumen therethrough, and the at least one axially directed connecting strut functions as the sole connection between the proximal implant segment and the distal implant segment. The axial length of the proximal implant segment is greater than the axial length of the distal implant segment, and the implant includes a shape memory material.

[0031] In the implant or other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the implant is configured such that the distal implant segment has a diameter different from the diameter of the proximal implant segment when the implant is in a non-stressed state. In some embodiments, the implant is configured such that the distal implant segment has a diameter smaller than the diameter of the proximal implant segment when the implant is in a non-stressed state. In some embodiments, the implant is configured such that the distal implant segment has a circumference different from the circumference of the proximal implant segment when the implant is in a non-stressed state. In some embodiments, the implant is configured such that the distal implant segment has a circumference smaller than the circumference of the proximal implant segment when the implant is in a non-stressed state. In some embodiments, the implant is configured such that the distal implant segment has a cross-sectional area different from the cross-sectional area of the proximal implant segment when the implant is in a non-stressed state. In some embodiments, the implant is configured such that the distal implant segment has a cross-sectional area smaller than the cross-sectional area of the proximal implant segment when the implant is in a non-stressed state. In some embodiments, the implant is configured such that the proximal implant segment has a variable diameter and / or cross-sectional area when the implant is in a non-stressed state. In some embodiments, the implant is configured such that the distal edge of the proximal implant segment includes continuous struts and / or rings. In some embodiments, the implant is configured such that the distal edge of the proximal implant segment includes continuous struts and / or rings having one or more anchors. In some embodiments, the implant is configured such that the proximal implant segment includes struts of uniform length. In some embodiments, the implant is configured such that the proximal implant segment includes struts of variable length and / or variable width. In some embodiments, the implant is configured such that the proximal implant segment includes struts having a length different from the length of the struts of the distal implant segment.In some embodiments, the implant is configured such that when the implant is in a non-stressed state, the distal implant segment is longitudinally offset from the proximal implant segment. In some embodiments, the proximal implant segment includes a biocompatible graft material. In some embodiments, the distal implant segment includes a biodegradable graft material. In some embodiments, the implant includes a porous or non-porous laminate layer. In some embodiments, the implant includes a coating containing heparin and / or a therapeutic agent.

[0032] In some embodiments, an endoluminal implant for forming an arteriovenous fistula is disclosed. This includes a proximal implant segment including a proximal end and a distal end, configured to extend through a perforating vein and a deep vein, and with its proximal end configured to be positioned within the perforating vein, and a distal implant segment connected to the proximal implant segment and configured to be positioned within an artery adjacent to the deep vein, where the distal end of the proximal implant segment is configured to have an angle with respect to the axis of the distal implant segment. The proximal implant segment is configured to direct flow from the artery towards a superficial vein connected to the perforating vein.

[0033] In the above implant or other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the proximal implant segment and the distal implant segment include expandable tubular bodies. In some embodiments, the intraluminal implant includes a side opening between the distal end of the proximal implant segment and the proximal end of the distal implant segment, and blood flowing through the artery flows into the side opening and (i) flows through the proximal end of the distal implant segment, exits from the distal end of the distal implant segment, and continues to flow through the artery, (ii) flows through the distal end of the proximal implant segment, exits from the proximal end of the proximal implant segment, and flows into the perforating vein and then into the superficial vein. In some embodiments, the proximal implant segment has an angle between about 0 degrees and about 90 degrees with respect to the axis of the distal implant segment.

[0034] In some embodiments, an endovascular implant for forming an arteriovenous fistula is disclosed. The endovascular implant includes a venous implant segment including a first expandable tubular body having a first end and a second end and a lumen extending therein, the first expandable tubular body being configured to be foldable for delivery to a patient and expandable to radially engage the inner wall of a vein, and an arterial implant segment including a second expandable tubular body having a first end, a second end, and a lumen therethrough, the second expandable tubular body being configured to be foldable for delivery to a patient and expandable to radially engage the inner wall of an artery positioned adjacent to the vein. The second end of the venous implant segment is connected to the first end of the arterial implant segment such that when the venous implant segment and the arterial implant segment are in an expanded configuration, the arterial implant segment can be angled with respect to the venous implant segment, and by having the arterial implant segment angled with respect to the venous implant segment, the distance between the second end of the venous implant segment and the first end of the arterial implant segment increases along one side of the implant, providing a side opening in the implant. When the venous implant segment radially engages the inner wall of the vein and the arterial implant segment radially engages the inner wall of the artery adjacent to the vein, blood flowing through the artery flows into the side opening and (i) flows through the first end of the arterial implant segment and out of the second end of the arterial implant segment, and (ii) flows through the second end of the venous implant and out of the first end of the venous implant segment.

[0035] In some embodiments, a delivery device for delivering a vascular implant between a vein and an artery is disclosed. The delivery device includes an outer sheath configured to constrain the implant in a low-profile configuration at its distal end, and a nose cone including a proximal end, a distal end, and a cavity. Here, to advance the distal ends of the nose cone and the outer sheath through the vein to the artery, the distal end of the sheath is insertable into the cavity. The outer sheath is retractable proximally relative to the nose cone to expand the distal segment of the implant within the cavity, the outer sheath is further retractable proximally relative to the nose cone to expand the proximal segment of the implant within the vein, and the nose cone is advanceable distally relative to the distal segment of the implant within the artery to release the distal segment of the implant from the cavity after the proximal segment has been expanded within the vein.

[0036] In the above-described system, or in other embodiments described herein, one or more of the following features may also be provided. In some embodiments, the distal end of the nose cone is tapered. In some embodiments, the proximal end of the nose cone is tapered. In some embodiments, the proximal end of the nose cone has an angle with respect to the longitudinal length of the nose cone. In some embodiments, the proximal tapered end of the nose cone is configured to engage the proximal wall of the artery after the nose cone has advanced into the artery. In some embodiments, after the distal segment of the implant has been released within the artery, the distal end of the outer sheath is capable of advancing into the cavity through the distal segment of the implant. In some embodiments, after the distal segment of the implant has been released within the artery, the distal end of the outer sheath is capable of advancing through the distal segment of the implant and engaging the proximal end of the nose cone such that the nose cone enters the distal end of the outer sheath. In some embodiments, the delivery device further includes a guide wire shaft configured to advance over a guide wire, and the nose cone is fixed to the guide wire shaft. In some embodiments, the delivery device further includes a control knob connected to the proximal end of the outer sheath and configured to retract and / or advance the outer sheath by movement of the delivery device to its proximal side and / or distal side, and the control knob is at least partially disposed within the handle of the delivery device. In some embodiments, the control knob is configured to be releasably locked in the most proximal position and / or the most distal position within the handle. In some embodiments, the delivery device further includes an intermediate shaft within the outer sheath and configured to prevent the implant from sliding proximally during retraction of the outer sheath. In some embodiments, when the outer sheath advances into the cavity, the distal end of the intermediate shaft leads the distal end of the outer sheath. In some embodiments, the delivery device further includes an intermediate shaft connector disposed within the handle and connected to the proximal end of the intermediate shaft, and the intermediate shaft connector is configured to engage the control knob and advance the intermediate shaft with the outer sheath when the outer sheath advances into the cavity. In some embodiments, the implant is constrained within the distal end of the outer sheath.

[0037] In some embodiments, a method of forming an arteriovenous fistula between a patient's artery and vein is disclosed. The method includes delivering to the patient an endoluminal implant in a collapsed configuration, the endoluminal implant including a venous implant segment including a first tubular body and an arterial implant segment including a second tubular body, the venous implant segment being connected to the arterial implant segment; extending the endoluminal implant across any interstitial cavity between the artery and vein; radially expanding the venous implant segment to radially engage the vein and radially expanding the arterial implant segment to radially engage the artery, wherein when the venous and arterial implant segments radially engage the vein and artery, respectively, the arterial implant segment is angled with respect to the venous implant segment, providing a side opening in the endoluminal implant, which allows blood flowing in the artery to flow into the side opening and (i) continue to the artery through the second tubular body of the arterial implant segment and (ii) flow into the vein through the first tubular body of the venous implant segment.

[0038] In some embodiments, an endoluminal implant including an implant frame is disclosed. The implant frame can include struts. The implant frame may be covered with an inner layer of a porous graft material such as PTFE and an outer layer of a porous graft material such as ePTFE. The inner layer and the outer layer can be melted to encapsulate the implant frame. A thermoplastic laminate layer may be disposed between the inner layer and the outer layer of the porous graft material to facilitate bonding of the inner layer and the outer layer. The thermoplastic laminate layer may be disposed on the outer surface of the implant frame and the outer layer of the porous graft material may be applied over the thermoplastic laminate layer. The thermoplastic laminate layer may be non-porous. In some embodiments, the thermoplastic laminate layer may be a strip spirally wound between the inner layer and the outer layer. The thermoplastic laminate layer may be composed of a fluorinated ethylene propylene (FEP), polyethylene (PE), or thermoplastic polyurethane (TPU) film. In some embodiments, the thermoplastic laminate layer may be wound such that a gap remains between each wrap of the thermoplastic laminate layer. In embodiments composed of a proximal implant segment and a distal implant segment as described elsewhere herein, the gap may be provided along at least the proximal portion of the proximal implant segment to impart additional flexibility to the proximal implant segment. In some embodiments, no gap is provided at the distal portion of the proximal implant segment and / or no gap is provided in the distal implant segment.

[0039] In some embodiments, methods, systems, or devices are disclosed that include any number of features of the present disclosure, consist essentially of any number of features of the present disclosure, consist of any number of features of the present disclosure, and / or do not include any number of features of the present disclosure.

[0040] The foregoing and other features, aspects, and advantages of the embodiments of the systems, devices, and methods described herein will be described in detail below with reference to the drawings of various embodiments. The drawings illustrate embodiments of the invention and are not intended to be limiting. The drawings include the following figures.

Brief Description of the Drawings

[0041]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16A

Figure 16B

Figure 16C

Figure 16D

Figure 17A

Figure 17B

Figure 17C

Figure 17D

Figure 17E

Figure 17F

Figure 17G

Figure 17H

Figure 17I

Figure 18A

Figure 18B

Figure 18C

Figure 18D

Figure 19A

Figure 19B

Figure 20A

Figure 20B

Figure 20C

Figure 21

Figure 22A

Figure 22B

Figure 23A

Figure 23B

Figure 24A

Figure 24B

Figure 24C

Figure 24D

Figure 24E

Figure 24F

Figure 24G

Figure 24H

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Figure 30

Figure 31

Figure 32

Figure 33

Figure 34

Figure 35

Figure 36

Figure 37

Figure 38

Figure 39

Figure 40

Figure 41

Figure 42

DETAILED DESCRIPTION OF THE INVENTION

[0042] Throughout the drawings, unless otherwise specified, reference numerals may be reused to show the general correspondence between the referenced elements. The drawings are provided to illustrate the exemplary embodiments described herein and are not intended to limit the scope of the present disclosure.

[0043] Embodiments disclosed herein generally relate to medical devices and methods. More specifically, some embodiments relate to intravascular implants and methods and devices for efficiently and accurately positioning them within the vasculature. In some embodiments, the devices, methods, and systems described herein enable accurate placement of devices such as stents including covered stents, and other implants and anastomosis devices for arteriovenous fistula (AVF) formation, while minimizing or eliminating the need for X-ray imaging, such that they can be implemented in a clinical environment using only non-invasive imaging techniques of percutaneous ultrasound (e.g., high-resolution ultrasound systems such as high-frequency linear transducers (about 9 - 15 MHz)). In some embodiments, novel means for temporarily engaging anatomical structures are utilized when delivering intravascular implants. Further, in some embodiments, the implants, devices, systems, and / or methods described herein advantageously overcome some or all of the drawbacks of existing implants, devices, systems, and / or methods for forming AVFs. This includes bypassing deep vein branches that may undesirably divert the arterial blood flow path from the desired superficial vein, and preventing or reducing secondary procedures such as ligation and embolization.

[0044] FIG. 1 schematically shows a portion of the vasculature of a human arm having a skin surface, e.g., a dermal surface 28. Location 7 is a potential area for forming an anastomosis between a first body lumen and a second body lumen, such as an artery and a vein, e.g., an AVF between a deep artery 4 adjacent to a deep vein 3. The perforating vein 2 connects the superficial vein 1 to the adjacent deep vein 3 and provides a conduit for accessing location 7. The AVF may also be formed between the perforating vein 2 and the artery 4, bypassing the deep vein 3. In some embodiments, the AVF between the perforating vein 2 and the artery 4 can redirect blood from the artery to the superficial vein 1 connected to the perforating vein 2.

[0045] Figures 2A, 2B, 2C, and 2D illustrate some embodiments of a method for percutaneously introducing intravascular guidewire 5 into deep artery 4 using needle access tool 35. An example of intravascular guidewire 5 has a diameter of about 0.018 inches and a length of about 80 cm. An example of a suitable guidewire 5 is Nitrex® (manufactured by Medtronic) 5 cm angled tip #N180802. Needle access tool 35 can include a hollow needle having a proximal port 30 and a distal tip 34 slidably disposed within sheath 33. The hollow needle can be an echo - genic needle such as an echo - genic 21g needle. The hollow needle can be about 7 cm in length. An example of a suitable needle is Cook Micropuncture® set #G43869. Sheath 33 is connected to hub 32 having a compression element such as compression spring 31 disposed between port 30 and hub 32. When proximal port 30 is depressed, needle tip 34 is exposed distal to the distal end of sheath 33, enabling penetration of tissue such as skin and blood vessels. When proximal port 30 is not depressed, spring 31 extends and moves needle tip 34 proximally so that needle tip 34 is not exposed. In this configuration, the needle access device can move through the vascular system with reduced risk of inadvertent puncture or trauma to the vascular system. Using this feature of needle access tool 35 and a suitable imaging technique such as percutaneous ultrasound, as shown in Figure 2A, the needle access tool is first introduced into superficial vein 1. With needle tip 34 retracted within sheath 33, as shown in Figure 2B, the needle access tool is moved to position 7 using a suitable imaging means. While at position 7, proximal port 30 is manipulated (e.g., depressed) to expose needle tip 34, and then needle access tool 35 is advanced to penetrate the vessel wall and any interstitial tissue between deep vein 3 and deep artery 4 and place the distal end of sheath 33 into the lumen of deep artery 4. While maintaining this position, guidewire 5 is introduced into proximal port 30 and advanced through needle access tool 35 so that, as shown in Figure 2C, the distal end of guidewire 5 exits the distal end of needle access tool 35 and enters the lumen of deep artery 4. Figure 2D shows guidewire 5 having a curve 6 formed when guidewire 5 conforms to the anatomical shape of a particular blood vessel.The needle access tool 35 can have alternative embodiments that can include a distal end curved to facilitate progression through the vasculature, a hemostatic valve attached to the proximal port 30, and a spring-loaded hollow needle capable of assisting in puncturing a movable structure. For AVF formation, a location alternative to location 7 may be selected. For example, if the distance between the deep vein 3 and the deep artery 4 at location 7 is shorter, a more distal location along the deep vein 3 may be advantageous. Some embodiments are not limited to connections between deep veins and deep arteries in the upper or lower extremities, such as the hand, forearm, upper arm, foot, lower leg, thigh, etc. Some embodiments can be used to accurately position implants in other luminal structures such as superficial veins and arteries, coronary arteries, gynecological structures (e.g., vagina, cervix, uterus, or fallopian tubes), urological structures (e.g., ureters, bladder, or urethra), and gastrointestinal structures (e.g., esophagus, stomach, small intestine, large intestine, rectum, bile ducts, etc.).

[0046] Figure 3 shows the distal end of the intravascular delivery system 29 with a distal nose cone 8 having a distal tapering portion 10, a cavity 9 (e.g., a central lumen), and a proximal tapering end 11 being introduced into the vasculature and approaching the AVF location 7 on a guide wire 5 having a curvature 6. The outer sheath 12 is shown restraining the implant 13 in a low-profile (e.g., collapsed) configuration, and the distal end of the outer sheath 12 is inserted into the cavity 9. The delivery system 29 is shown having a curvature adapted to the guide wire 5 and the anatomical shape of the blood vessel. The delivery system 29 may be flexible or relatively rigid compared to the surrounding vascular structures and the guide wire 5. The nose cone 8 has a distal tapering portion 10, thereby allowing easier penetration of the vessel wall and any interstitial tissue at the AVF location 7. In one embodiment, the most distal end of the distal tapering portion 10 may have a sharp tip to further facilitate penetration into various tissues. The nose cone 8 has features for accommodating the guide wire 5, and in this embodiment, is adhesively or otherwise fixed to the inner guide wire shaft 22. This is shown in Figure 8 but not in Figure 3.

[0047] FIG. 4 shows the nose cone 8 of the delivery system 29 entering the deep artery 4 across the AVF location 7. The intermediate shaft 16 is shown slidably disposed within the outer sheath 12. The intermediate shaft 16 is slidably disposed about a guide wire shaft 22 not shown in FIG. 4. Also shown is a gap 14 that can form when the delivery system 29 follows the curvature of the guide wire and the nose cone 8 and the outer sheath 12 are no longer coaxial. The gap 14 can be defined, in some embodiments, as the open space between the proximal opening of the nose cone 8 and the sidewall of the outer sheath 12 when the outer sheath 12 enters the proximal opening of the nose cone 8. In some embodiments, the gap has a length and / or diameter that is about, at least about, or up to about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or the like of the respective length and / or diameter of the proximal opening of the nose cone 8, or is in a range that includes any two of the above values. In some embodiments, no gap is formed and / or is not required between the proximal opening of the nose cone 8 and the sidewall of the outer sheath 12.

[0048] The angle 15 between the central (e.g., longitudinal) axis of the nose cone 8 and the central (e.g., longitudinal) axis of the outer sheath 12 can be formed when the distal end of the delivery system 29 is in a curved configuration where the proximal end of the proximal tapered end 11 is outside the curve, as shown in FIG. 4. In some embodiments, the angle 15 is, for example, about, at least about, or up to about 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, or the like, and is in a range including any two of the above values. To increase the flexibility between the nose cone 8 and the outer sheath 12, the nose cone 8 may have slits in the wall forming the cavity 9. In some embodiments, the curvature of the guide wire 5 can be utilized to form the angle 15 and thus the gap 14. Alternative means for forming the angle 15 and the gap 14 may be utilized. Alternative embodiments may use one, two, or more pull wires, for example, to bias the distal end of the delivery system 29 such that the gap 14 is formed. Depending on the desired clinical outcome, various operable and / or biasable elements can be utilized. In some cases, the gap 14 can also be formed by the difference between the outer diameter of the outer sheath 12 and the inner diameter of the cavity 9 of the nose cone 8.

[0049] FIG. 5 shows the nose cone 8 engaging the proximal wall of the deep artery 4 after the delivery system 29 has been retracted proximally from the position of FIG. 4. The engagement between the nose cone 8 and the proximal wall of the deep artery 4 may be due to a gap 14 that can be formed when the delivery system 29 is pushed into the curved configuration with the proximal end of the proximal tapered tip 11 outside the curved portion. In some embodiments, the nose cone 8 can engage the proximal wall of the artery without requiring the gap 14. For example, the proximal end of the proximal tapered tip 11 can engage the proximal wall of the deep artery 4, for example, by utilizing the first surface 64 (shown in FIG. 22B), without a gap 14 between the proximal tapered tip 11 and the outer sheath 12. Also shown is the deformation of the anatomical structure at the AVF location 7 as a result of the juxtaposition force between the proximal wall of the deep artery 4 and the proximal tapered tip 11 of the nose cone 8. This deformation of the anatomical structure at the AVF location 7 is visualized by ultrasound and can be utilized to confirm proper tissue engagement and / or implant placement prior to delivery. One way to visualize this engagement and confirm by ultrasound that the nose cone 8 is properly oriented during deployment of the implant 13 is to use a long-axis view that includes both the entire length of the perforating vein 2 and the deep artery 4.

[0050] Figure 6A shows the first step of the first stage of delivery of an elastically constrained (e.g., folded) implant 13 according to some embodiments. While the nose cone 8 is juxtaposed against the proximal wall of the deep artery 4, the outer sheath 12 can be retracted proximally, whereby the elastically constrained (e.g., folded) implant 13 can be expanded at the precise position defined by the engagement of the nose cone 8 and the proximal wall of the deep artery 4. The distal end of the intermediate shaft 16 remains fixed during delivery so that the elastically constrained (e.g., folded) implant 13 does not slide proximally during retraction of the outer sheath 12. Also shown is the state in which the distal implant segment 18 is partially constrained (e.g., partially folded) in the cavity 9. For example, the axially oriented connector strut 20, as shown, connects the distal implant segment 18 to the proximal implant segment 19, which is not yet fully released (e.g., expanded) in FIG. 6A. Also, partially constrained (e.g., partially folded) within the cavity 9 are one or more anchors 17. Shown in FIG. 6A is the radial expansion at the AVF location 7 due to the radial stiffness of the elastically expanding implant 13. The distal end of the proximal implant segment 19 may be angled with respect to the axis of the distal implant segment 18 of the implant so as not to occlude the deep artery 4 while still fully entering and supporting the region between the walls of both the deep vein 3 and the deep artery 4. In some embodiments, the distal end of the proximal implant segment 19 may have an angle of from about 0 degrees to about 90 degrees with respect to the axis of the distal implant segment 18.

[0051] In some embodiments, as shown also in FIG. 6B, when the outer sheath 12 retracts proximally, one or more anchors 17 may be released. The (one or more) anchors 17 may engage the proximal wall of the deep artery 4 (as shown in FIG. 6B), the wall of the deep vein 3, the wall of the perforating vein 2, the wall of the superficial vein 1, and / or the above or any interstitial tissue. In some embodiments, the anchor 17 may include a proximal anchor that extends in the proximal direction after being unconstrained (e.g., expanded or released). In one example, one or more anchors 17 can extend distally from the distal end of the proximal implant segment 19 while being constrained by the outer sheath 12 or the nose cone 8, as described below. After the outer sheath 12 has retracted, the anchor 17 is capable of transitioning to an expanded (e.g., unconstrained or released) configuration, where the anchor extends radially outwardly and curves or bends in the proximal direction to facilitate engagement with the vessel wall or interstitial tissue. In other examples, as shown in FIGS. 18A - 18C below, the anchor may extend in the proximal direction while being constrained by the outer sheath 12 or the nose cone and when the constraint is released.

[0052] FIG. 7A shows, following FIG. 6A, the continued delivery (e.g., expansion) of the elastically constrained (e.g., folded) implant 13 while further retracting the outer sheath 12 until the proximal implant segment 19 is completely released (e.g., expanded) from the outer sheath 12. FIG. 7B shows, following FIG. 6B, the continued delivery (e.g., expansion) of the elastically constrained (e.g., folded) implant 13 while further retracting the outer sheath 12 until the proximal implant segment 19 is completely released (e.g., expanded) from the outer sheath 12.

[0053] Figure 8 shows the delivery of the distal implant segment 18 of the implant 13 and the release of the (one or more) anchors 17 in some embodiments. Advancing the nose cone 8 distally by advancing the guide wire shaft 22 distally causes the distal implant segment 18 to be held in its axial position by the connector strut 20, thereby being slidably released from the cavity 9. In some embodiments, the (one or more) anchors 17, which may be shaped, for example, in a hook configuration, may be elastically released from the cavity 9 as the nose cone 8 advances and may assume a hook shape to secure the most proximal portion of the distal edge of the proximal implant segment 19 to the proximal wall of the deep artery 4. In some embodiments, the (one or more) anchors 17 may be released as the outer sheath 12 retracts proximally and as the nose cone 8 advances distally. In alternative embodiments, there are no (one or more) anchors 17 since sufficient fixation is provided by the juxtaposition of the struts of the implant 13 and the surrounding anatomical structures.

[0054] In the illustrated embodiment, the distal implant segment 18 provides means for fixing the most distal portion of the distal edge of the proximal implant segment 19 so as not to penetrate into the lumen space of the deep artery 4. The distal implant segment 18 may also provide radial support to the deep artery 4 in order to ensure patency and sufficient distal blood flow after implantation of the implant 13. The distal implant segment 18 can be sized to be accommodated within the deep artery 4. In some embodiments, the diameter of the distal implant segment 18 is 0% to 50% larger than the diameter of the deep artery 4. In other embodiments, the diameter of the distal implant segment 18 is 5% to 25% larger than the diameter of the deep artery 4. In some embodiments, the proximal implant segment 19 has a diameter of from about 2 mm to about 7 mm. In some embodiments, the distal implant segment 18 has a diameter of from about 2 mm to about 7 mm. In some embodiments, the proximal implant segment 19 and the distal implant segment 18 may have substantially the same diameter. In some embodiments, the proximal implant segment 19 and the distal implant segment 18 may have different diameters. In some embodiments, the proximal implant segment 19 has a diameter of about 5 mm and the distal implant segment 18 has a diameter of about 4 mm. In some embodiments, the distal implant segment 18 has a diameter of about 4 mm and the proximal implant segment 19 is tapered, with the distal end of the proximal implant segment 19 having a diameter of about 4 mm and the proximal end of the proximal implant segment 19 having a diameter of about 5 mm. In some embodiments, the proximal implant segment 19 and / or the distal implant segment 18 need not have a circular cross-sectional shape. Instead, both may have the same or different cross-sectional areas and / or perimeters. In some embodiments, the distal implant segment 18 portion of the implant 13 does not exist. In some embodiments, the distal implant segment 18 portion of the implant 13 does not exist and the distal end of the proximal implant segment 19 may include a continuous strut and / or a ring, also referred to as an anastomotic ring.In some embodiments, the distal implant segment 18 portion of the implant 13 is absent, and the distal end of the proximal implant segment 19 may include continuous struts and / or rings having skirts and / or flanges that extend into the deep artery 4 and seal against the proximal wall of the deep artery 4 upon deployment.

[0055] FIG. 9 shows the first step of removing the delivery system 29 in which, according to some embodiments, the outer sheath 12 and the intermediate shaft 16 advance distally through the delivered (e.g., expanded) implant 13 into the cavity 9. In some embodiments, the intermediate shaft 16 leads the outer sheath 12 during this advancement step, facilitating secure engagement of the outer sheath 12 with the cavity 9 without the outer sheath 12 catching the proximal end 11 of the distal nose cone 8.

[0056] FIG. 10A shows the continuation of the removal of the delivery system 29, rotating the delivery system 29 about the axis, for example, by about 180 degrees such that the proximal portion of the proximal tapered end 11 of the nose cone 8 is inside the bend 6. In this orientation, the gap 14 is minimized, eliminated, or substantially eliminated such that the proximal tapered end 11 and the outer sheath 12 are flush and in contact. This rope profile configuration facilitates removal of the nose cone 8 without engaging either the delivered implant 13 or the anatomical features in the vicinity of the AVF location 7.

[0057] Figure 10B shows an alternative embodiment for providing a removal configuration of the rope profile for the delivery system 29. In this embodiment, before advancing the outer sheath 12 through the implant 13, the nose cone 8 is rotated about the axis, for example, by about 180 degrees. After the rotation of the nose cone 8, the outer sheath 12 is advanced through the implant 13 and engaged with the proximal end of the proximal tapered end 11. Due to the tapered structure of the proximal tapered end 11, when the outer sheath 12 is advanced, the proximal tapered end 11 can enter the inner diameter of the outer sheath 12. In this configuration, there is no structure in the delivery system 29 that can interfere with the removal from the body. To complete the removal in this embodiment, the delivery system is retracted while maintaining the outer sheath 12 overlapping the nose cone 8 until it exits the body.

[0058] Figure 11 shows the continuation of the removal of the delivery system 29 in the configuration shown in Figure 10A. Due to its rope profile configuration, the proximal tapered end enters the delivered (e.g., expanded) distal implant segment 18 without interference. A preferred embodiment is one in which the implant 13 has an unconstrained delivery inner diameter dimension that is larger than the outer diameter dimension of the nose cone 8 so that when the nose cone 8 is removed through the implant 13, it does not cause excessive resistance or interference with the implant 13.

[0059] Figure 12 shows a further continuation of the removal of the delivery system 29. The delivery system 29 is further retracted and the nose cone 8 has moved partway through the proximal implant segment 19 of the implant 13.

[0060] Figure 13 shows the continuation of the removal of the delivery system 29. The delivery system 29 has been completely retracted through the implant 13. Due to the curvature of the anatomical structure at this position, the gap 14 can be formed again. If the gap 14 causes excessive resistance to the continued removal of the delivery system 29 from the body, the delivery system 29 can be rotated again to minimize and / or eliminate the gap 14 and minimize the resistance to the removal of the delivery system 29.

[0061] FIG. 14 shows the start of removal of the guide wire 5 from the body. Prior to removal of the guide wire 5, it may be desirable or advantageous to advance a balloon dilation catheter of appropriate dimensions relative to the implant 13 and the vasculature to facilitate complete expansion of the implant 13. In some embodiments with proximal implant segment 19 and distal implant segment 18 having different diameters, cross-sectional areas, and / or perimeters, balloon dilation catheters of different dimensions may be used to facilitate complete expansion of the proximal implant segment 19 and the distal implant segment 18. For example, in some embodiments, a semi-compliant, rapid exchange, percutaneous transluminal angioplasty balloon of 4 mm × 20 mm or 2 mm × 30 mm may be used. The balloon dilation catheter can be used to facilitate complete expansion of the implant 13, such as when blood flow is insufficient (e.g., less than about 200 ml / min) and the implant 13 cannot maintain complete expansion. One cause of insufficient blood flow through the implant 13 is vasospasm outside the implant 13. When used, the balloon dilation catheter can extend across the entire implant 13 (both the distal implant segment 18 and the proximal implant segment 19), and can also target adjacent veins and arteries.

[0062] FIG. 15 shows the completion of the implant 13, where the distal implant segment 18 is in the deep artery 4 and the proximal segment 19 forms an AVF between the deep vein 3 and the deep artery 4. In this embodiment, the implant 13 is at least partially positioned and fixed by the anchor(s) 17 (which are directed proximally as shown in the figure) and the distal implant segment 18. Also, alternative anchor functions such as barbs can be utilized in some embodiments. The anchor and / or barbs of the implant 13 can extend in the proximal direction, distal direction, bi-directionally (e.g., both proximal and distal directions), and / or at an angle with respect to the proximal and distal directions. The implant 13 is shown with the proximal implant segment 19 having the anchor and / or barbs, but in some embodiments, the distal implant segment 18 can include the anchor and / or barbs as described herein. In some embodiments, one or both of the proximal implant segment 19 and the distal implant segment 18 can comprise one or more anchors configured to fix one or both of the segments to the vein wall, artery wall, and / or interstitial tissue.

[0063] In a preferred embodiment, the implant 13 is coated or sealed with a biocompatible graft material such as ePTFE. This can promote endovascular healing while minimizing lumen stenosis due to hyperplasia. In some embodiments, the sealing with the graft material may consist of a laminate that combines an inner layer of a porous graft material such as ePTFE that coats the inner surface of the implant 13 and an outer layer of a porous graft material such as ePTFE that coats the outer surface of the implant 13. In some embodiments, the bonding of the inner and outer layers of the porous graft material can be achieved by sealing the struts of the implant 13 and fusing the outer and inner layers with heat and compression. In these and other embodiments, a thermoplastic laminate layer such as a fluorinated ethylene propylene (FEP) film, polyethylene (PE), or thermoplastic polyurethane film (TPU) may be disposed between the inner and outer layers of the porous graft material to facilitate bonding. In some embodiments, the thermoplastic laminate layer may be porous, and in other embodiments, the laminate layer may be non-porous. In some embodiments, the porosity of the encapsulated implant 13 may be maintained by spirally wrapping a strip of a non-porous thermoplastic laminate layer between the inner and outer layers of the porous graft material and leaving a gap between each wrap of the thermoplastic laminate layer. In some embodiments, there is no gap between each wrap of the thermoplastic laminate layer, and the final assembly is non-porous but has a porous surface. Coating or sealing the proximal implant segment 19 with the graft material can prevent infiltration of blood between the deep vein 3 and the deep artery 4 or into any interstitial tissue that can induce hematoma, infection, and other complications. Coating the proximal implant segment 19 with the graft material also helps redirect the blood flow from the deep artery 4 to the superficial vein 1.

[0064] Figures 16A, 16B, and 16C show one embodiment of the implant 13. Figure 16A shows a pattern intended to be cut from a superelastic tube, such as a superelastic NiTi tube, to form the features of the implant 13 (for example, the implant 13 can be formed from a single laser-cut hypotube). A cross-section of the cut pattern forming the proximal implant segment 19, the distal implant segment 18, the (one or more) anchors 17, and the connector strut 20 is shown. In some embodiments, the implant 13 may alternatively be made of a superelastic wire or of a rolled and cut superelastic sheet stock. Figure 16B shows the shape of the implant 13 after the pattern of Figure 16A has been cut out of the tube. Figure 16C shows the implant 13 having the distal implant segment 18, the proximal implant segment 19, and the connector strut 20 after being shaped using well-known techniques from a superelastic tube, such as a superelastic NiTi tube. As shown in the figure, the proximal implant segment 19 and / or the distal implant segment 18 can be composed of a plurality of struts.

[0065] Also shown in Figure 16C is a graft material 38 that covers the inner diameter of the proximal segment 19. The graft material 38 can be used to cover the inner diameter, the outer diameter, or both the inner and outer diameters of any part (e.g., all or less than all) of the implant 13, depending on the needs in the particular application. Expanded polytetrafluoroethylene, also known as ePTFE, has proven to be an advantageous graft coating for intravascular implants. Other materials, such as polyester mesh, may also be suitable for specific embodiments. The implant 13 may be coated or sealed with a biocompatible graft material, as described elsewhere in this specification.

[0066] In some embodiments, the proximal implant segment 19 can include an elongate tubular member or tube having a proximal end, a distal end, an axis therethrough, and a flow path / lumen therethrough. In some embodiments, the distal implant segment 18 can include an elongate tubular member or tube having a proximal end, a distal end, an axis therethrough, and a flow path / lumen therethrough. The proximal implant segment 19 and / or the distal implant segment 18 can be linear when unconstrained (e.g., when expanded), in a pre-shaped state, or at rest, as shown in the figures. Further, as shown in the figures, the proximal implant segment 19 can have an axial length that is longer than the axial length of the distal implant segment 18. In some embodiments, the distal implant segment 18 can be disposed downstream (e.g., downstream with respect to the direction of arterial blood flow) of the position of the distal end of the proximal implant segment 19. In some embodiments, the implant 13 can have a more basic structure that does not have a proximal segment, a distal segment, and / or an anchoring function and simply requires accurate placement within the body.

[0067] In some embodiments, the anchoring function of the implant 13, such as the (one or more) anchors 17, may form an angle of about 10 degrees to about 90 degrees in the proximal and / or distal directions relative to the body of the implant 13. In some embodiments, the anchoring function of the implant 13, such as the (one or more) anchors 17, may form an angle of about 35 degrees to about 40 degrees in the proximal and / or distal directions relative to the body of the implant 13. The implant 13 may be made of a bioabsorbable material such as PLA, PGA, PLLA, or other materials suitable for a particular application. The implant 13 may also be coated on its inner surface, outer / external surface, or both the inner surface and the outer / external surface with heparin and / or therapeutic agents including agents and compounds well known for reducing intimal hyperplasia and / or restenosis in intravascular implant applications. In some embodiments, the implant 13 according to FIGS. 16A - 16C is only partially coated or sealed with a biocompatible graft material and may include a laminate layer and / or a coating. For example, only the proximal implant segment 19 may be coated / sealed with a biocompatible graft material, have a laminate layer, and be coated.

[0068] In some embodiments, as shown in FIG. 16D, during manufacture, the implant frame 41 (e.g., the struts described herein) may be placed on top of the inner layer 43 of a porous graft material such as ePTFE. The inner layer 43 may extend over the length of a segment of the implant 13 (e.g., the proximal implant segment 19) or the entire length of the implant 13. As schematically shown in FIG. 16D, a helical wrap of a strip 45 of a thermoplastic laminate (e.g., FEP), which may be non-porous, is wound around the implant frame 41 such that no gap is left on one side of the implant frame 41 (e.g., the more distal segment), and a gap 49 is left between each wrap or turn of the strip 45 on the opposite side of the implant frame 41 (e.g., the more proximal segment) to increase the flexibility of bending. The flexibility is increased because the region where the strip 45 of the thermoplastic laminate material is wound becomes harder. Thus, regions where the thermoplastic material is not wound, such as the exposed portion 41a of the implant frame 41, i.e., the region where there is a gap 49 in the helical winding of the strip 45 of the thermoplastic laminate layer, can be more flexible. In some embodiments, the proximal implant segment 19 may include a gap 49 between one or more turns of the strip 45, e.g., between three adjacent turns. The strip 45 can be applied in part or in whole to adjacent strut rows of the proximal implant segment 19. In some embodiments, the gap 49 is formed in the proximal portion of the proximal implant segment 19, which is the portion where additional flexibility is desired, but is not formed in the distal portion of the proximal implant segment 19, which is a non-porous portion where it is desired to prevent blood infiltration. In some embodiments, the gap 49 between the turns of the strip 45 can be aligned with the gap between adjacent rows of struts of the implant frame 41. The exposed portion 41a of the implant frame 41 corresponding to the gap 49 is not covered by the strip 45 and can have more flexibility. It is possible to increase the flexibility of the proximal implant segment 19 to provide a bending ability as shown, for example, in FIGS. 18D and 19B.The second or outer layer (not shown) of a porous graft material, such as ePTFE, may be coated on a strip 45 around which a laminate layer is wound, including the exposed portion 41a of the implant frame 41. Pressure and heat can be used to melt the laminate layer and fuse the inner layer 43 and the outer layer that embeds the implant frame 41 therebetween.

[0069] Figures 17A - 17I illustrate one embodiment of the implant 13. Figure 17A shows a pattern intended to be cut from a superelastic tube, such as a superelastic NiTi tube, to form the features of the implant 13 (e.g., the implant 13 can be formed from a single laser - cut hypotube). A cross - section of the cut pattern forming the proximal implant segment 19, the distal implant segment 18, and the connector strut 20 that connects the proximal implant segment 19 to the distal implant segment 18 is shown. In some embodiments, the implant 13 includes one or more anchors 17, as additionally shown in the cut pattern. In some embodiments, the proximal implant segment 19 can include a long tubular member or tube having a proximal end, a distal end, an axis passing therethrough, and a flow path therethrough. In some embodiments, the distal implant segment 18 can include a long tubular member or tube having a proximal end, a distal end, an axis passing therethrough, and a flow path / lumen therethrough. In some embodiments, the distal implant segment 18 may be disposed downstream (e.g., downstream with respect to the direction of arterial blood flow) of the position of the distal end of the proximal implant segment 19.

[0070] In some embodiments, implant 13 includes a continuous strut / ring 21 (also referred to as an anastomotic ring) at the distal edge of the proximal implant segment 19 (e.g., at the distal edge of the distal end of the proximal implant segment 19), as additionally shown in the cut pattern. As shown in FIG. 17A, the continuous strut / ring 21 may include strut elements 21A, 21B, 21C, 21D, 21E, 21F, and 21A', and the strut elements 21A and 21A' are continuous with each other (i.e., they are shown separately in FIG. 17A because they are in a cut pattern in that figure. When cut into a tube, the strut elements 21A and 21A' are continuous with each other). In some embodiments, the continuous strut / ring 21 can provide a continuous distal edge to the proximal implant segment 19 to reduce wrinkles in the graft material being sealed. In some embodiments, the continuous strut / ring 21 can provide a continuous distal edge to the proximal implant segment 19 to improve the sealing performance of the implant 13 on the inner wall of the deep artery 4. In some embodiments, the continuous strut / ring 21 can increase the radial stiffness of the distal edge of the proximal implant segment 19 to help maintain the diameter and / or cross-sectional area of the fistula (e.g., an increase in radial stiffness can lead to an increase in the radial expansion of the fistula).

[0071] In some embodiments, the proximal implant segment 19 may include struts of different lengths, and a cut pattern portion forming short struts 36 and long struts 37 is further shown. In some embodiments, in addition to being longer, struts 37 may be thicker and wider than struts 36. In some embodiments, the position of the longer and / or thicker / wider struts 37 may be such as to form a larger diameter and / or cross-sectional area of the implant 13 relative to the diameter and / or cross-sectional area of the implant 13 where the struts 36 are located. In some embodiments, the position of the longer and / or thicker / wider struts 37 may be such as to increase the radial stiffness of the implant 13 relative to the radial stiffness of the implant 13 where the struts 36 are located. In some cases, thinner struts may be used to reduce the radial stiffness of the implant at that location. When the struts are long, the radial stiffness of the implant at that location may decrease. In some embodiments, the distal end and / or proximal end of the proximal and / or distal implant segment may have a lower radial stiffness compared to the radial stiffness along their axial length (e.g., to reduce mechanical stress concentration at the blood vessel / implant interface).

[0072] In some embodiments, the implant 13 may alternatively be made of a superelastic wire or from a rolled and cut superelastic sheet stock. FIGS. 17B - 17E are a perspective view, a side view, a top view, and a bottom view, respectively, of the implant 13 after being cut from a superelastic tube such as a NiTi tube according to the pattern of FIG. 17A and shape - set, and includes a distal implant segment 18, a proximal implant segment 19, a connector strut 20, one or more proximal anchors 17, a continuous strut / ring 21, short struts 36, and long struts 37. FIGS. 17F - 17I are a front (distal end) view, a back (proximal end) view, a front (distal end) view through the longitudinal axis of the distal implant segment 18, and a back (proximal end) view through the longitudinal axis of the proximal implant segment 19, respectively, of the implant 13 after being cut from a superelastic tube such as a NiTi tube according to the pattern of FIG. 17A and shape - set, and shows the implant 13 having some of the various features identified in FIGS. 17A - 17E. Although not shown in FIGS. 17A - 17I, the implant 13 of FIGS. 17A - 17I may include any one or more of the features described in connection with the implant 13 herein, including implants of FIGS. 8, 15, and 16A - 16C, such as being coated or sealed with a biocompatible graft material, having a laminate layer, and being coated with heparin and / or other therapeutic agents. In some embodiments, the implant 13 according to FIGS. 17A - 17I may be coated or sealed only partially with a biocompatible graft material and may include a laminate layer and / or a coating. For example, only the proximal implant segment 19 may be coated / sealed with a biocompatible graft material, have a laminate layer, and be coated.

[0073] Figures 18A - 18B show various embodiments of the implant 13 as described herein, after being shaped and sealed with a biocompatible graft material. The implant 13 of Figure 18A can correspond to the implant 13 described in Figures 17A - 17I and is shown including a distal implant segment 18, a proximal implant segment 19, a connector strut 20, one or more anchors 17, a continuous strut / ring 21, a short strut 36, and a long strut 37. As shown in the figure and according to some embodiments, the portion of the proximal implant segment 19 where the longer strut 37 is located is formed to have a larger diameter than the diameter of the proximal implant segment 19 where the shorter strut 36 is located. In other words, in some embodiments, the proximal implant segment 19 may be tapered such that the distal end of the proximal implant segment 19 can have a different (e.g., smaller) diameter than the proximal end of the proximal implant segment 19. In an alternative embodiment as shown in Figure 18B, the proximal implant segment 19 of the implant 13 may be composed of struts having a substantially uniform diameter and a substantially the same length. Figure 18B also shows various features of the implant 13 described herein, including a distal implant segment 18, the aforementioned proximal implant segment 19, a connector strut 20, one or more anchors 17, and a continuous strut / ring 21. The implant 13 of an alternative embodiment as shown in Figure 18C can include a distal implant segment 18, a proximal implant segment 19, a connector strut 20, one or more anchors 17, a continuous strut / ring 21, a short strut 36, and a long strut 37. Figure 18C also shows a proximal implant segment 19 that can be tapered such that the distal end of the proximal implant segment 19 can have a different (e.g., smaller) diameter than the proximal end of the proximal implant segment 19. Further, the proximal implant segment 19 shown in Figure 18C is shorter than those shown in Figures 18A and 18B and has four (instead of six) struts 36, 37.It is emphasized that the proximal implant segment 19 shown in FIGS. 18A to 18C is not limited to the lengths shown in the individual figures. Also, as shown in FIGS. 18A to 18C, the proximal implant segment 19 and / or the distal implant segment 18 of the implant 13 may be linear in the unconstrained configuration, or the shape-setting configuration, or the stationary configuration. Further, as shown in the figures, the proximal implant segment 19 may have an axial length longer than that of the distal implant segment 18. Further, as shown in the figures, the proximal implant segment 19 can be oriented at an angle with respect to the distal implant segment 19 when the proximal and distal implant segments are fully extended in the stationary configuration.

[0074] FIG. 18D shows the implant 13 according to FIGS. 17A-17I and FIGS. 18A-18C with the non-flexed state and the flexed state superimposed on each other as described herein. The non-flexed state and the flexed state of the implant 13 can correspond to the state of the implant 13 after implantation in a patient as described herein, such as when the patient's arm is substantially straight with respect to the elbow (corresponding to the non-flexed state) and when the patient's arm is substantially flexed at the elbow (corresponding to the flexed state). As shown in the figure, the proximal implant segment 19 is configured to bend or curve away from the side opening 60 with respect to the distal implant segment. As shown in the figure, the proximal implant segment 19 can bend or curve away from the side opening 60 with respect to the distal implant segment 18 by at least 90 degrees. In some embodiments, the proximal implant segment 19 can bend or curve away from the side opening 60 with respect to the distal implant segment 18 by at least about 35 degrees, at least about 40 degrees, at least about 45 degrees, at least about 50 degrees, at least about 55 degrees, at least about 60 degrees, at least about 65 degrees, at least about 70 degrees, at least about 75 degrees, at least about 80 degrees, at least about 85 degrees, at least about 90 degrees, at least about 95 degrees, at least about 100 degrees, at least about 105 degrees, at least about 110 degrees, at least about 115 degrees, at least about 120 degrees, at least about 125 degrees, at least about 130 degrees, at least about 135 degrees, at least about 140 degrees, at least about 145 degrees, at least about 150 degrees, at least about 155 degrees, at least about 160 degrees, at least about 165 degrees, at least about 170 degrees, at least about 175 degrees, at least about 180 degrees, or more, or at any angle. The proximal implant segment 19 can bend or curve with respect to the distal implant segment 18 and, when bent or curved, remains substantially open / uncapped so that flow can pass through (e.g., blood flow through the proximal implant segment 19 does not decrease even when bent).Furthermore, the proximal implant segment 19 can bend or curve without twisting or flattening (e.g., becoming an elliptical cross-section) relative to the distal implant segment 18. In other words, the proximal implant segment 19 can bend or curve relative to the distal implant segment 18 and maintain a cross-sectional area that is substantially the same or identical to the non-bent state. Such a configuration of the proximal implant segment 19 minimizes and / or eliminates the force exerted from the implant to the blood vessel into which it is implanted when the blood vessel bends and / or deforms due to patient movement (e.g., movement of the patient's arm about the elbow). The proximal implant segment 19 can bend or curve relative to the distal implant segment 18 with a radius of curvature R of bending / curving of about 6 mm, about 5.5 mm, about 5.0 mm, about 4.5 mm, about 4.0 mm, about 3.5 mm, about 3.0 mm, about 2.9 mm, about 2.8 mm, about 2.7 mm, about 2.6 mm, about 2.5 mm, about 2.4 mm, about 2.3 mm, about 2.2 mm, about 2.1 mm, about 2.0 mm, less than about 2.0 mm, or greater than about 6 mm, or any range therebetween.

[0075] FIG. 19A shows another embodiment of the implant 13, specifically a pattern cut from a superelastic tube, such as a superelastic NiTi tube, for the purpose of forming the features of the implant 13 (e.g., the implant 13 can be formed from a single laser-cut hypotube). The implant 13 according to FIG. 19A may be the same as or similar to the implant 13 described herein and / or incorporate any one or more of the features described and / or illustrated with respect to the implant 13. For example, the implant 13 shown in FIG. 19A includes a proximal implant segment 19 having a plurality of struts with a continuous strut / ring 21 (e.g., an anastomotic ring) at the distal end, a distal implant segment 18 having a plurality of struts connected to the proximal implant 19 by connecting struts 20, a side opening 60 between the proximal implant segment and the distal implant segment, and one or more anchors 17 oriented in the proximal and / or distal directions. The implant 13 can be configured such that the proximal implant segment 19 has a different flexibility than the distal implant segment 18. For example, as discussed later, the proximal implant segment 19 can be configured to have a greater flexibility than the distal implant segment 18. The high flexibility of the implant 13, particularly the proximal implant segment 19, advantageously minimizes the stress on the blood vessel(s) in which the implant 13 is implanted and allows for the movement of the blood vessel(s) as they would normally move in the absence of the implant 13. Since the stress on the blood vessel(s) can cause intimal hyperplasia and incomplete healing, the flexible implant 13 avoids such situations and helps to promote healing.

[0076] The proximal implant segment 19 can comprise a series of strut rows arranged substantially circumferentially about the axis of the proximal implant segment 19, which in some embodiments can constitute wavy struts as shown in the figures. These series of strut rows of the proximal implant segment 19 can be interconnected by one or more axially extending struts 61 arranged substantially along the axis of the proximal implant segment 19. Similarly, the distal implant segment 18 can comprise a series of strut rows arranged substantially circumferentially about the axis of the distal implant segment 18, which in some embodiments can constitute wavy struts as shown in the figures. These series of strut rows of the distal implant segment 18 can be interconnected by one or more axially extending struts 61 arranged substantially along the axis of the distal implant segment 18. To achieve greater flexibility of the proximal implant segment 18 relative to the distal implant segment 18 as described above, in some embodiments, the series of strut rows of the distal implant segment 18 can be connected by axially extending struts 61 that are at least one more than the series of strut rows of the proximal implant segment 19. For example, as shown in the figures, adjacent strut rows of the proximal implant segment 19 can be connected by only one axially extending strut 61, and adjacent strut rows of the distal implant segment 18 can be connected by two (e.g., at least one more) axially extending struts 61.

[0077] In addition to, or alternatively to, the number of struts extending axially of the proximal implant segment 19 that have an effect on relative flexibility, the position of struts extending axially of such proximal implant segment 19 can affect the flexibility of the proximal implant segment 19 (and similarly the flexibility of the distal implant segment 18). As shown in FIG. 19A, most or all of the one or more axially extending struts 61 of the proximal implant segment 19 can be disposed at the side of the proximal implant segment 19 that is aligned with the position of the side opening 60 (which corresponds to the central portion of the implant 13 extending from left to right in the illustrated cut pattern). The side aligned with the side opening 60 can be up to about 90 degrees circumferentially on both sides of the circumferential center of the side opening. As shown in FIG. 19A, the sides aligned with the side opening 60 up to about 90 degrees circumferentially on both sides of the circumferential center of the side opening can have the connection struts 20 spaced about 180 degrees apart. By avoiding having axially extending struts 61 on the side of the implant 13 opposite the side opening 60, when the proximal implant segment 19 bends or curves, the adjacent strut rows of the proximal implant segment can move closer to each other without the axially extending struts 61 inhibiting the bending movement. Further, when the proximal implant segment 19 bends or curves, the graft material 38 of the proximal implant segment 19 in regions such as the region opposite the side opening can be folded or wrinkled.

[0078] In some embodiments, adjacent strut rows disposed substantially circumferentially about the axis of the proximal implant segment 19 and / or the distal implant segment 18 can be connected only by the graft material / coating 38, without axially extending struts 61. In such embodiments, the implant frame can be composed of an assembly of strut rows held by the graft material / coating 38, rather than being cut out of a tube with a laser. Such embodiments can provide a highly flexible proximal implant segment 19 and / or distal implant segment 18. In some cases, and in any of the implants 13 described herein, the struts disposed substantially circumferentially about the axis of the proximal implant segment 19 and / or the distal implant segment 18 can be formed as rings rather than wavy struts, and / or can include a mixture of rings and wavy struts.

[0079] FIG. 19B shows the implant 13 according to FIG. 19A with the non-flexed state and the flexed state superposed on each other as described herein. The non-flexed state and the flexed state of the implant 13 can correspond to the state of the implant 13 after implantation in a patient as described herein, such as when the patient's arm is substantially straight with respect to the elbow (corresponding to the non-flexed state) and when the patient's arm is substantially flexed at the elbow (corresponding to the flexed state). As shown in the figure, the proximal implant segment 19 is configured to bend or curve away from the side opening 60 with respect to the distal implant segment. As shown in the figure, the proximal implant segment 19 can bend or curve at least 180 degrees away from the side opening 60 with respect to the distal implant segment 18. In some embodiments, the proximal implant segment 19 can bend or curve away from the side opening 60 with respect to the distal implant segment 18 by at least about 35 degrees, at least about 40 degrees, at least about 45 degrees, at least about 50 degrees, at least about 55 degrees, at least about 60 degrees, at least about 65 degrees, at least about 70 degrees, at least about 75 degrees, at least about 80 degrees, at least about 85 degrees, at least about 90 degrees, at least about 95 degrees, at least about 100 degrees, at least about 105 degrees, at least about 110 degrees, at least about 115 degrees, at least about 120 degrees, at least about 125 degrees, at least about 130 degrees, at least about 135 degrees, at least about 140 degrees, at least about 145 degrees, at least about 150 degrees, at least about 155 degrees, at least about 160 degrees, at least about 165 degrees, at least about 170 degrees, at least about 175 degrees, at least about 180 degrees, at least about 185 degrees, at least about 190 degrees, at least about 195 degrees, at least about 200 degrees, at least about 205 degrees, at least about 210 degrees, at least about 215 degrees, or more, or at any angle. The proximal implant segment 19 can bend or curve with respect to the distal implant segment 18 and, when bent or curved, remains substantially open / uncapped so that flow can pass through (e.g., blood flow through the proximal implant segment 19 does not decrease even when bent).Furthermore, the proximal implant segment 19 can bend or curve without twisting or flattening (e.g., becoming an elliptical cross-section) relative to the distal implant segment 18. In other words, the proximal implant segment 19 can bend or curve relative to the distal implant segment 18 and can remain substantially the same or identical in cross-sectional area as in the non-bent state. Such a configuration of the proximal implant segment 19 is advantageous in that it can minimize and / or eliminate the force exerted from the implant to the blood vessel into which it is implanted when the blood vessel bends and / or deforms due to the patient's movement (e.g., the movement of the patient's arm around the elbow). The proximal implant segment 19 can bend or curve relative to the distal implant segment 18 with a radius of curvature R of bending / curving of about 6 mm, about 5.5 mm, about 5.0 mm, about 4.5 mm, about 4.0 mm, about 3.5 mm, about 3.0 mm, about 2.9 mm, about 2.8 mm, about 2.7 mm, about 2.6 mm, about 2.5 mm, about 2.4 mm, about 2.3 mm, about 2.2 mm, about 2.1 mm, about 2.0 mm, less than about 2.0 mm, more than about 6 mm, or any range therebetween. The proximal implant segment 19 of the implant 13 in FIG. 19A may have improved flexibility compared to the proximal implant segment 19 of the implant 13 shown in FIG. 18A due to the configuration (e.g., number and position) of the axially extending struts 61.

[0080] Figures 20A - 20B show another embodiment of the implant 13, specifically an implant cut from a superelastic tube such as a superelastic NiTi tube and shaped into the form described herein. Figure 20A shows a side view of the implant 13 and Figure 20B shows a perspective view. The implant 13 according to Figures 20A - 20B may be the same as or similar to the implant 13 described herein and / or incorporate any one or more of the features described and / or illustrated with respect to the implant 13. For example, the implant 13 shown in Figures 20A - 20B includes a proximal implant segment 19 having a plurality of struts of a continuous strut / ring 21 (e.g., an anastomotic ring) at the distal end, a distal implant segment 18 having a plurality of struts connected to the proximal implant 19 by connecting struts 20, a side opening 60 between the proximal implant segment and the distal implant segment, and one or more anchors 17. What is different from other embodiments described herein is that the distal implant segment 18 of the implant 13 according to Figures 20A - 20B can be configured as at least a partial tubular body extending from its proximal end to its distal end. In such a configuration, the distal implant segment 18 can provide at least partial radial support against the arterial wall on the opposite side of the distal end of the proximal implant segment, as shown in Figure 20C where the implant 13 is implanted within the patient's vasculature. The distal implant segment 18 according to Figures 20A - 20 is shown to have a partial tubular body extending circumferentially approximately 180 degrees from one connecting strut 20 to another connecting strut 20. However, in other configurations of the distal implant segment 18, it is possible to include a partial tubular body extending circumferentially less than approximately 180 degrees (in which case the connecting strut 20 can have a different configuration), or a partial tubular body extending circumferentially more than 180 degrees.For example, the distal implant segment 18 can be configured as a partial tubular body that extends radially at an angle of about 30 degrees, about 45 degrees, about 60 degrees, about 75 degrees, about 90 degrees, about 105 degrees, about 120 degrees, about 135 degrees, about 150 degrees, about 165 degrees, about 180 degrees, about 195 degrees, about 205 degrees, about 220 degrees, about 235 degrees, about 250 degrees, about 275 degrees, about 290 degrees, about 305 degrees, about 320 degrees, about 335 degrees, or any angle that exceeds, is between, or is greater than these values. In one embodiment, as shown in the figure, the partial tubular body forming the distal implant segment may be oriented or aligned on the same implant side as the side opening 60.

[0081] Figure 21 is a partial cross-sectional view of various elements of one embodiment of delivery system 29. A nose cone 8 having a distal tip 10 and a proximal tip 11 is shown connected to a guide wire shaft 22. The guide wire shaft 22 has an internal lumen for accommodating a guide wire 5 (shown elsewhere). An intermediate shaft 16 is slidably disposed on the guide wire shaft 22, slidably disposed within an outer sheath 12, and abuts the proximal end of an implanted device 13 that is constrained (e.g., folded). The proximal end of the intermediate shaft 16 terminates at a position fixed to the proximal handle 23 or at a position movable relative to the handle 23. The intermediate shaft 16 prevents the implanted device 13 from moving relative to the guide wire shaft 22 as the outer sheath 12 retracts during delivery of the implanted device 16. The implanted device 13 is elastically constrained (e.g., folded) within the outer sheath 12. The outer shaft 12 is attached to a control knob 26 slidably mounted to the handle 23, whereby controlled retraction of the outer sheath 12 is possible by sliding the control knob 26 proximally. The distal end of the outer sheath 12 terminates within the cavity 9 of the nose cone 8. At the proximal end, the guide wire shaft 22 is fixed to the handle 23 and is lumenally connected to a tube 25 that provides a conduit for the guide wire 5 to move completely within the delivery system 29. A hemostatic valve may be attached to the proximal end of the tube 25 to prevent backflow of blood when the delivery system 29 is inserted into the vasculature. Also shown in FIG. 21 are a proximal handle 24 to facilitate operation of the delivery system 29 and several constrained (e.g., folded) elements of the implanted device 13, including a distal implanted device segment 18, a proximal implanted device segment 19, and a connector strut 20. A handle nose cone 27 provides a guide path and support for the outer sheath 12 slidably disposed within the handle nose cone 27. FIG. 21 shows a preferred embodiment of the delivery system. Alternative preferred embodiments of the delivery system 29 may include a thumbwheel control and a pull wire function for the outer sheath 12. These do not rely on the curvature 6 of the guide wire 5 as shown in FIG. 6 and allow the nose cone 8 to be actively biased to form a gap 14.The structural material of the delivery system 29 may be any material well known for use in catheter structures, such as PEEK, HDPE, PeBax, nylon, PTFE, combinations thereof, and others. The diameter and length of the delivery system 29 need to be adapted to a particular application. In one embodiment, the outer profile of the nose cone 8 is 6Fr to 9Fr for an implant 13 having a diameter of 3 mm to 6 mm. In one embodiment, the distance between the handle 23 and the nose cone 8 is from about 15 cm to about 30 cm. Various lengths and diameters of the delivery system 29 are used in various embodiments of the present invention to meet the needs of particular applications.

[0082] Figure 22 shows a perspective view and a cross-sectional view of the nose cone 8. The nose cone 8 generally has a tubular shape with a distal end, a proximal end, and a longitudinal axis extending therebetween. According to some embodiments, the proximal tapered end 11 is shown with an outer shape intended to engage tissue when the gap 14 is formed and not engage tissue or the implant structure when the gap 14 disappears. In some embodiments, the proximal tapered end 11 can engage tissue without the gap 14 (as shown and described in relation to FIG. 22B). In some cases, the proximal tapered end 11 may engage tissue when directed substantially outside a curve (such as the bend 6, etc.) and not engage tissue when directed substantially inside the curve. The nose cone 8 can include a proximal opening that forms a cavity (such as a central lumen) 9 that is sized to receive an outer sheath 12 (not shown). The nose cone 8 also includes an opening that extends from the distal end of the cavity 9 to the tapered distal end 10, allowing a guide wire (such as the guide wire 5) to extend longitudinally to the nose cone 8. The proximal end of the nose cone 8 may be inclined with respect to the longitudinal axis of the nose cone 8 in some embodiments. As shown in the figure, the most proximal tip 63 of the nose cone 8 can be radially aligned with the inner diameter of the cavity 9. Further, as shown in the bottom longitudinal cross-sectional view, the proximal end 11 of the nose cone 8 has a surface that extends distally and radially outward from the most proximal tip 63 to the outer diameter of the nose cone, and can form the proximal tapered end 11. To improve the flexibility between the nose cone 8 and the outer sheath 12, the wall forming the cavity 9 may include slits or slots, preferably in the region of the short wall portion forming the cavity 9 shown in the cross-sectional view of the nose cone 8. The nose cone 8 includes a tapered distal portion 10 to facilitate sliding over a guide wire 5 (not shown) and passing through anatomical structures that have not yet been expanded to a diameter equal to or greater than the outer diameter of the nose cone 8. The tapered portion 10 may be tapered distally in some cases, as shown in the figure. The nose cone 8 can be constructed from materials well known to be suitable for catheters, such as PEEK, HDPE, polypropylene, etc.In some embodiments, the nose cone 8 may include echogenic features to assist with ultrasonic visualization.

[0083] FIG. 22B shows a perspective view and a cross-sectional view of an enlarged proximal tapered end 11 of the nose cone 8, according to some embodiments. The nose cone 8 according to FIG. 22B may be the same as or similar to the nose cone 8 described herein, such as the nose cone described with respect to FIG. 22A, and / or incorporate any one or more features described and / or illustrated with respect thereto. Different from other embodiments described herein, the proximal tapered end 11 of the nose cone 8 according to FIG. 22B can be configured to engage tissue without the need to form a gap 14 (e.g., without the need for a gap between the inner diameter of the cavity 9 and the outer sheath 12 when the outer sheath 12 is disposed within the cavity 9). To achieve this, the most proximal tip 63 of the nose cone 8 may be spaced radially outwardly from the inner diameter of the cavity 9 as shown in FIG. 22B. In other words, the most proximal tip 63 can be spaced radially outwardly from the virtual projection of the inner diameter of the proximal cavity 9 to form a radial gap between the most proximal tip 63 and the virtual projection of the inner diameter. This radial gap allows the most proximal tip 63 to engage tissue such as the wall of a vein or artery in which the nose cone is disposed. According to FIG. 22B, the proximal tapered end 11 of the nose cone 8 thus comprises a first surface 64 extending proximally and radially outwardly from the inner diameter of the proximal cavity towards the most proximal tip 63, and a second surface 65 extending distally and radially outwardly from the most proximal tip 63 towards the outer diameter of the nose cone, as shown in the longitudinal cross-section and an enlarged view thereof. The first surface 64 can engage the proximal wall of the deep artery 4 after the delivery system 29 is pulled proximally from its position as shown in FIG. 5, without the need to form a gap 14 as shown in FIG. 5.

[0084] Figures 23A - 23B show perspective and cross - sectional views of the handle 23 and its various elements. The handle nose cone 27 is shown attached to the distal end of the handle 23 having a through - lumen for slidably receiving an outer sheath 12 (not shown). The control knob 26 is slidably constrained within the handle 23 and is used to control the axial position of the outer sheath 12 (not shown). The tube 25 allows a guide wire 5 (not shown) to pass through the handle 23.

[0085] Figures 24A - 24H show another embodiment of the delivery system or delivery device 29. The delivery device is configurable for percutaneous access to a patient's arm or another location. Figure 24A shows a perspective view of the delivery device 29 according to this and some embodiments, Figure 24B shows a cross - sectional perspective view, and Figure 24C shows an exploded perspective view. Further, Figure 24D shows a cross - sectional view of the distal end of the delivery device 29, and Figure 24E shows a perspective view of the delivery device 29 with a portion of the handle housing removed from view. The delivery device 29 shown in Figures 24A - 24H may share common elements with the delivery device 29 shown in Figures 21 - 23B and function similarly. Thus, the common elements may share common reference numbers to indicate the general correspondence between the referenced elements.

[0086] As shown in FIGS. 24A - 24H, the delivery device 29 can include a handle 23, a control knob 26, a guide wire shaft 22, an intermediate shaft 16, an outer sheath 12, and a nose cone 8. The handle 23 can include a right housing 42 and a left housing 44, which can be fixed to each other by mechanical fixtures, adhesives, or by being shaped to snap - fit or press - fit. As shown in FIG. 24A, the handle 23 can include a proximal handle 24 at its proximal end that can facilitate the operation of the delivery device 29. Also, as shown in FIG. 24A, the handle 23 can include a nose cone 27 having a through - lumen at its distal end, thereby providing a guide path and support for the outer sheath 12 that is slidably disposed within the handle 23 and the nose cone 27. Also, as shown in FIG. 24A, the control knob 26 is slidably constrained within the longitudinal opening of the handle 23, and a portion of the control knob 26 extends outside the handle 23 as shown for user operation. The nose cone 8 is disposed at the distal end of the delivery device 29 and can include features as described herein.

[0087] The perspective cross-sectional view of FIG. 24B and the exploded perspective view of FIG. 24C show additional details of an embodiment of a portion of the delivery device 29 shown in FIG. 24A. As shown in the figures, the guide wire shaft 22 may traverse the longitudinal length of the handle 23. The proximal end of the guide wire shaft 22 may be fluidly connected to a guide wire shaft connector 55 that is partially disposed within the handle 23 at the proximal end of the handle 23. The guide wire shaft connector 55 may be similar to the tube 25 described herein. The guide wire shaft connector 55 may extend proximally beyond the handle 23 and terminate at a guide wire shaft connector fitting 56 that is connectable to a valve and / or tube for controlling backflow of blood when the delivery device 29 is inserted into the vasculature. The guide wire shaft connector 55, when fluidly connected to the guide wire shaft 22, forms a common lumen with the guide wire shaft 22, such that the guide wire 5 described herein can be inserted into the proximal end of the guide wire shaft connector 55 (e.g., through the guide wire shaft connector fitting 56), pass through the guide wire shaft connector 55, and then move through the guide wire shaft 22 as the guide wire 5 moves distally. Also, as shown in the figures, a guide wire shaft housing connector 57 may be disposed within the handle 23 distally of the guide wire shaft connector fitting 56, and the guide wire shaft housing connector 57 may be attached to the guide wire 22 and configured to provide support (e.g., mechanical support) to the guide wire 22. Also, as shown in the figures, the delivery device 29 may further include an intermediate shaft connector 50 that is disposed within the handle 23 and configured to connect to the proximal end of the intermediate shaft 16. The delivery device 29 may further include an intermediate shaft connector stop 52, which may be a part of the handle 23 (e.g., a part of a molded article), as shown in the figures. Also, as shown in the figures, the control knob 26 may include a distal catch 47 and a proximal catch 48, which in some embodiments can interact with features of the handle 23 that include a distal housing catch 53 and a proximal housing catch 54.Further, the control knob 26 may also include a spring element 46 that can interact with the features of the handle 23.

[0088] The further connection and operation of the elements of the delivery device 29 according to some embodiments will now be described with reference to the cross-sectional view of FIG. 24D and the perspective view of FIG. 24E (showing the delivery device 29 with the left housing 44 of the delivery device 29 removed from the view). As shown in the figures, the guide wire shaft 22 extends substantially longitudinally within the handle 23 and can be connected to the guide wire shaft connector 55 at its proximal end as described above. Further, the guide wire may extend distally through the handle nose cone 27 and terminate distally at the connection with the nose cone 8. Thus, the guide wire shaft 22, in combination with the guide wire connector 55 and the nose cone 8, can form a central lumen configured to slidably receive the guide wire 5 as described herein (e.g., the guide wire 5 can slide within the delivery device 29 and / or the delivery device can slide along the guide wire 5).

[0089] The intermediate shaft 16 described herein may be coaxially disposed with the guide wire shaft 22 and may be slidably disposed along the guide wire shaft 22, and as shown in the figure, has a proximal end connected to an intermediate shaft connector 50 disposed within the handle 23 and a distal end that may terminate in front of the nose cone 8. Thus, the intermediate shaft 16 and the intermediate shaft connector 50 can move together slidably in the distal / proximal direction along the guide wire shaft 22. The intermediate shaft connector 50 can have a proximal end configured to abut against an intermediate shaft connector stop 52 when in its most proximal position and a distal end configured to interact with the control knob 26. In some embodiments, the intermediate shaft connector 50 can include an intermediate shaft connector recess 51 configured to engage the control knob 26 when the control knob 226 slides to its most proximal position within the handle 23. For example, the intermediate shaft connector recess 51 can frictionally engage the control knob 26 when the control knob 26 slides proximally and moves into the recess. As another example, the intermediate shaft connector recess 51 can include a protrusion that aids in holding / engaging the control knob 26 of the intermediate shaft connector 50 when the control knob 26 slides proximally and moves over the protrusion and into the recess.

[0090] The outer sheath 12 described in this specification may be arranged coaxially with the intermediate shaft 16 and may be arranged slidably along the intermediate shaft 16. As shown in the figure, it can have a proximal end connected to the control knob 26 and a distal end that can terminate inside, partially inside, or in the vicinity of the nose cone 8. Therefore, the outer sheath 12 and the control knob 26 can be slidably moved distally / proximally along the intermediate shaft 16. The control knob 26 includes a spring element 46 as shown in the figure, and can be configured to apply an upward force to the control knob 26 by the interaction between this spring element 46 and the inner surface of the handle 23 (for example, the longitudinally oriented inner surface). The control knob 26 can also include features that can interact with the handle 23 to maintain the control knob 26 at a desired position on the distal side and / or proximal side. For example, the control knob 26 can include a distal catch 47 and a proximal catch 48 (which may each be in the form of a stepped edge) arranged in the vicinity of its distal end and proximal end respectively. Also, the handle 23 includes a distal housing catch 53 and a proximal housing catch 54 in the vicinity of the position where the control knob 26 protrudes from the longitudinal opening of the handle 23 as shown in the figure, and each can be configured to interact with the distal catch 47 and the proximal catch 48. Furthermore, as shown in the figure, the distal housing catch 53 and the proximal housing catch 54 may be arranged adjacent to the distal end and proximal end of the longitudinal opening of the handle 23 respectively, and each can include a sloped surface facing the direction of the control knob 26 and a stepped edge facing away from the control knob 26. In such an embodiment, and further for this example, when the control knob 26 slides distally to reach the full distal position, the control knob 26 biases downward (for example, in the direction of the inside of the handle 23) when it contacts and moves on the sloped surface of the distal housing catch 53. Then when the stepped edge of the distal catch 47 passes through the stepped edge of the distal housing catch 53, the control knob 26 can return to a higher position inside the handle 23, and the control knob 26 is locked in a predetermined position by the interaction between the stepped edge of the distal catch 47 and the stepped edge of the distal housing catch 53.To unlock the control knob 26 from this distal position, the control knob 26 is pushed inward (against the upward force applied by the spring element 46) toward the center of the handle 23 to move the stepped edge of the distal catch 47 away from the stepped edge of the distal housing catch 53 (e.g., until they no longer overlap longitudinally), and then the control knob 26 can be slid proximally. Locking and unlocking of the control knob 26 at its most proximal position can be performed similarly using the corresponding proximal catch 48 and proximal housing catch 54. In some embodiments, when the control knob 26 slides proximally to its most proximal position, the control knob 26 engages with the intermediate shaft connector recess 51 of the intermediate shaft connector 50, locking the intermediate shaft connector 50 to the control knob 26. Subsequent movement / sliding of the control knob 26 allows the intermediate shaft connector 50 and the intermediate shaft 16 connected thereto to move with the control knob 26 and the outer sheath 12. The above-described intermediate shaft connector stop 52 can assist in the engagement between the intermediate shaft connector 50 and the control knob 26 by preventing the proximal movement of the intermediate shaft connector 50 when the control knob 26 moves proximally into the intermediate shaft connector recess 51. In some embodiments, the control knob 26 and the handle 23 can include other features that assist in locking the control knob 26 in a desired position. In some embodiments, the distal catch 47, proximal catch 48, distal housing catch 53, and proximal housing catch 54 may include features different from those described above but can function similarly.

[0091] As described herein and as shown in FIG. 24D, the distal end of the delivery device 29 can include a nose cone 8 that includes a distal tip detail 10, a cavity 9, and a proximal tip end 11. The distal tip detail 10 can be symmetric along the longitudinal length of the nose cone 8 and can form a longitudinal through-opening. In some embodiments, the guide wire shaft 22 can be attached to the nose cone 8 at the longitudinal through-opening. The longitudinal through-opening can include a diameter and / or cross-sectional area that is smaller than the diameter and / or cross-sectional area of the cavity 9. The cavity 9 can include a diameter and / or cross-sectional area that is larger than the outer diameter of the outer sheath 12. The nose cone 8 can include a proximal end that has an angle with respect to the longitudinal length of the nose cone 8. For example, and with reference to FIG. 24D, the nose cone 8 can include a proximal end that has an angle of about 30 degrees with respect to the longitudinal length of the nose cone 8. However, other angles may be used. In some embodiments, the nose cone 8 can include a proximal end that has an angle between about 5 degrees and about 90 degrees with respect to the longitudinal length of the nose cone 8. In some embodiments, the nose cone 8 can include a proximal end that has an angle of about 5 degrees, about 10 degrees, about 15 degrees, about 20 degrees, about 25 degrees, about 30 degrees, about 35 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 55 degrees, about 60 degrees, about 65 degrees, about 70 degrees, about 75 degrees, about 80 degrees, about 85 degrees, or about 90 degrees with respect to the longitudinal length of the nose cone 8. In some embodiments, the proximal end of the nose cone 8 having an angle can be configured such that the nose cone 8 preferentially biases in one direction and not in another direction. For example, the nose cone 8 as shown in FIG. 24D preferentially biases upward (i.e., the distal end of the nose cone 8 biases upward) and, due to the angled proximal end, cannot preferentially bias downward. In some embodiments, the distal end of the nose cone 8 can be inhibited from moving in a particular direction by the proximal end of the nose cone 8 having an angle substantially inhibiting movement (e.g., the proximal end of the nose cone inhibits movement by interaction with any of the guide wire shaft 22, the intermediate shaft 16, and / or the outer sheath 12).The proximal opposing edge of the proximal end of the nose cone 8 can include a tapered shape as shown, for example, in FIG. 22A, which is also known as the proximal tapered end 11 described herein. As shown in the figure, the proximal tapered end 11 of the nose cone 8 may be tapered so as to have a smaller cross-sectional area in the proximal direction. That is, it may include a tapered shape opposite to the distal tapered portion 10. Thus, the tapered shape of the proximal tapered end 11 can assist in the retraction of the nose cone 8 as described herein. In some embodiments, the proximal end of the nose cone 8 can include an annular, circular, elliptical, oval, pear-shaped, egg-shaped, or any symmetric or irregular cross-sectional shape. In some embodiments, the width of the proximal end of the nose cone 8 may be greater than the height of the proximal end of the nose cone 8 along the longitudinal axis of the nose cone 8. In some embodiments, the cavity 9 may be dimensioned larger than the outer diameter of the outer sheath 12. In some embodiments, the cavity 9 may have a width greater than its height.

[0092] The guidewire shaft 22 can provide a semi-rigid and semi-flexible conduit that extends from the handle 23 of the delivery device and functions as a catheter terminating at a distal end having a nose cone 8. Thus, during use, the distal or proximal position of the nose cone 8 within the body may be directly affected by the movement of the delivery device 29 distally or proximally by a clinician or the like operating the delivery device 29. As described herein, the movement of the intermediate shaft 16 and / or the outer sheath 12 distally and / or proximally can be controlled by the operation of the control knob 26 (e.g., by sliding the control knob 26 distally and / or proximally). The delivery device 29 can be configured for single-handed operation by a clinician / user / operator. The single-handed operation of the delivery device 29 has the advantage that the clinician / user / operator can keep the other hand free to perform additional procedures related to the treatment. Also, the single-handed operation of the delivery device 29 can reduce and / or eliminate the need for additional personnel to assist with the procedure. Further, the single-handed operation of the delivery device 29 also has the advantage of improving the efficiency of the procedure. The single-handed operation of the delivery device 29 also has the advantage that the clinician / user / operator can simultaneously control an ultrasonic imaging probe with the other hand during the procedure.

[0093] Figure 24F shows the distal end of the delivery system 29 according to some embodiments. Illustrated in Figure 24F are variants of the outer sheath 12 and the intermediate shaft 16 that can assist in the operation of the delivery device 29. As shown in the figure, the intermediate shaft 16 has a distal tapered end that facilitates the intermediate shaft 16 passing through the expanded implant 13 and / or entering into the cavity 9 of the nose cone 8. Also shown is that the outer sheath 12 has a distal tapered end that facilitates the outer sheath 12 passing through the expanded implant 13 and / or entering into the cavity 9 of the nose cone 8. Further, the intermediate shaft 16 can be interference-fitted with the guidewire shaft 22 and / or the outer sheath 12 can be interference-fitted with the intermediate shaft 16.

[0094] Figures 24G and 24H show a delivery system 29 that transports an implant in a radially compressed configuration, according to some embodiments. Figure 24G also shows a safety clip 39 removably disposed near the control knob 26. During shipping and until the start of use, the safety clip 39 can prevent the unintentional proximal sliding of the control knob 26. Prior to use, the safety clip 39 can be removed, thereby enabling the proximal movement of the control knob 26 that may be necessary for delivery of the implant 13 into the patient. In some embodiments, also as described herein and shown in Figure 24H, at least a portion of the implant 13 is disposed within the nose cone 8 and at least a portion of the implant 13 is disposed within the outer sheath 12. Figure 24H also shows a guide wire shaft 22 that extends distally beyond the distal tip of the nose cone 8. It is understood that the guide wire shaft 22 can extend distally beyond the distal tip of the nose cone 8, although this is not an essential feature of the illustrated embodiment.

[0095] Delivery device 29 can be used to percutaneously deliver the intracavitary implant 13 as described herein. In some embodiments, and as described herein, at least a portion of the implant 13 can be disposed within the cavity 9 of the nose cone 8. In some embodiments, at least a portion of the implant 13 may be disposed within the outer sheath 12. In some embodiments, the intermediate shaft 16 may abut an end (e.g., the proximal end) of the implant 13 when the implant is disposed within the delivery device 29. In some embodiments, the implant 13 may be slidably disposed on the guide wire shaft 22. In some embodiments, the implant can be at least partially disposed within the nose cone 8 cavity 9 while also being at least partially disposed within the outer sheath 22. In some embodiments, the implant 13 may be disposed within the delivery device 29 in a radially compressed (e.g., folded) configuration and packaged as a kit. In some embodiments, the kit can include the delivery device 29 and the implant 13. In some embodiments, the kit can further include a needle access tool 35 and / or a guide wire 5. In some embodiments, the delivery device 29 can be made for single use. In some embodiments, the delivery device 29 can be made reusable. In some embodiments, any of the components and devices described herein can be provided either sterilized or unsterilized.

[0096] Next, an explanation is provided, according to some embodiments, of a method by which the delivery device 29, described above with reference to FIGS. 24A-24I, can deliver the implant 13 percutaneously after the guide wire 5 has been positioned through the vascular system and an adjacent vascular system where it is desirable for the AVF to be connected. The following explanation is applicable to the delivery devices and methods described previously. In some embodiments, the delivery device 29 is slidably disposed on the guide wire sheath 22, slidably disposed within the outer sheath 12, at least partially disposed within the cavity 9 of the nose cone 8, and may include the implant 13 in a radially compressed (e.g., folded) configuration with the intermediate shaft 16 abutting at its proximal end. Further, the control knob 26 of the delivery device 29 as provided may be in its most distal position relative to the handle 23 of the delivery device 29 (and, in some embodiments, may be locked in the most distal position by the interaction of the distal catch 47 of the control knob 26 and the distal housing catch 53 of the handle 23). In some embodiments, the control knob 26 can be prevented from sliding proximally by the presence of the safety clip 39, as shown in FIG. 24G. After sliding distally along the guide wire 5 until the nose cone 8 is positioned beyond the desired AVF position within the lumen of the vascular system (see FIG. 4), the delivery device may be pulled back proximally to engage the nose cone 8 against the proximal wall of the vascular system as described herein (see FIG. 5).

[0097] For example, the delivery device may be introduced directly into a patient's vein (e.g., a perforating vein further described herein). Also, the nose cone 8 may be advanced into the proximal radial artery. Delivery may be performed under ultrasonic guidance. The nose cone may be rotated and oriented against the proximal wall of the radial artery where the arterial puncture is made. The nose cone 8 may be pulled back and aligned with the proximal wall of the radial artery. The position on the radial artery can be identified using a combination of tactile feedback (resistance when pulling back) and ultrasonic visualization.

[0098] With the delivery device 29 and its nose cone 8 in this position, the control knob 26 may be moved (e.g., slid) to its most proximal position relative to the handle 23 of the delivery device 29 to retract the outer sheath 12 proximally (see FIGS. 6A - 6B). In some embodiments, this can include unlocking the distal catch 47 of the control knob 26 from the distal housing catch 53 of the handle 23 before the control knob 26 is movable proximally, and can also include locking the control knob 26 in its most proximal position by the interaction of the proximal catch 48 of the control knob 26 and the proximal housing catch 54 of the handle 23. In some cases, the aforementioned safety clip 39 is removed. The proximal retraction of the outer sheath 12 allows at least a portion of the implant 13 to expand radially within the lumen of the adjacent vascular system (e.g., within the penetrating vein), and may also allow at least a portion of the implant to expand within the cavity 9 of the nose cone 8. In some embodiments, when the control knob 26 moves to its most proximal position within the handle 23 of the delivery device 29, it can engage the intermediate shaft connector 50 and lock the intermediate shaft connector 50 to the control knob 26. In some cases, the control knob 26 may first move a short distance in the proximal direction, e.g., 1 - 2 mm, to confirm that the nose cone is in the proper position and then continue the movement of the control knob 26.

[0099] With the control knob 26 maintained in its most proximal position, the delivery device 29 is advanced distally on the guide wire 5 to completely release the implant 13 from the cavity 9 of the nose cone 8, enabling the implant to be fully radially expanded within the lumen of the vascular system (see Figure 8). For example, the delivery device 29 can be advanced at least 5 cm. The control knob 26 may be moved (e.g., slid) from its most proximal position to its most distal position relative to the handle 23 (which may include, in some embodiments, unlocking the proximal catch 48 from the proximal housing catch 54 and relocking the distal catch 47 to the distal housing catch 54), whereby both the intermediate shaft 16 and the outer sheath 12 advance distally through the radially expanded implant and engage the nose cone 8 as described herein (see Figure 9). The delivery device 29 can be rotated (e.g., rotated approximately 180 degrees) to form a smooth transition between the nose cone 8 and the outer sheath 12. (For example, any gap 14 as described herein can be eliminated. See Figures 10A or 10B). Then, it can be retracted proximally and completely removed from the body. (See Figures 11 - 14).

[0100] The structural material of the delivery device 29 can be any material well known for use in catheter structures, such as PEEK, HDPE, PeBax, nylon, PTFE, combinations thereof, and others. The diameter and length of the delivery device 29 can be adapted to specific applications. In one embodiment, the outer shape of the nose cone 8 is 6Fr to 9Fr for an implant 13 with a diameter of 3 mm to 6 mm. In some embodiments, the distance between the handle 23 and the nose cone 8 can be from about 15 cm to about 30 cm. The various lengths and diameters of the delivery system 29 are used in various embodiments of the present invention to meet the needs of specific applications. The nose cone 8 can be constructed from materials well known to be suitable for catheters, such as PEEK, HDPE, polypropylene, etc. In some embodiments, the nose cone 8 may include echogenic features to assist in ultrasonic visualization.

[0101] In some embodiments, the delivery device 29 may include a mesh or other wrap disposed around the implant 13 to maintain the implant 13 in a radially compressed (e.g., elastically constrained) configuration. In such embodiments, by pulling on a thread or wire of the mesh or wrap configured to tear the mesh or wrap and release the implant 13, the implant 13 may be released from its radially compressed configuration and expanded to its radially expanded configuration. Further, in such embodiments, the delivery device 29 may not require an outer sheath 12 or an intermediate shaft 16.

[0102] Returning to the simplified diagram of a portion of the vascular system of the human arm shown in FIG. 1, the location 7, which is a potential area for forming an anastomosis, may be adjacent to the bifurcation of the brachial vein and the radial vein near the perforating vein where the radial artery passes through. For example, as shown in FIG. 1, the artery 4 may include the radial artery, the deep vein 3 may include the brachial vein and / or the radial vein (e.g., the vein on the left side of location 7 may be the brachial vein, and the vein on the right side of location 7 may be the radial vein), the perforating vein 2 may include the perforating vein, and the superficial vein 1 may include the cephalic vein. Before implantation of the implant 13, the blood flow may be as follows, as described in connection with FIG. 1: the blood flow in the radial artery (e.g., artery 4) may be from left to right, the blood flow in the brachial vein and the radial vein (e.g., deep vein 3) may be from right to left, the blood flow in the perforating vein (e.g., perforating vein 2) may be an upward and leftward oblique blood flow from the brachial vein and / or the radial vein to the cephalic vein, and the blood flow in the cephalic vein (e.g., superficial vein 1) may be from right to left.

[0103] In some embodiments, several preparatory steps may be performed before placing the guidewire 5 (as shown in FIGS. 2A - 2D). Local anesthesia (e.g., axillary block or supraclavicular block) may be administered to the patient. The patient's arm can be placed in a 90° abducted position on an arm board. Also, pretreatment of the surrounding skin up to the axilla can be performed.

[0104] Returning to FIGS. 2A-2D, in some embodiments, the guide wire 5 can be percutaneously placed, passing through the wall of the radial cutaneous vein (e.g., superficial vein 1), through the cubital perforator vein (e.g., perforator vein 2), through the brachial vein or radial vein (e.g., deep vein 3), through the wall of the brachial vein or radial vein (e.g., deep vein 3), through any interstitial tissue between the brachial vein or radial vein and the radial artery (e.g., artery 4), through the wall of the radial artery (e.g., artery 4), and into the radial artery (e.g., artery 4). In some embodiments, the placement steps of the guide wire 5 can include the following. First, a sterilized elastic hemostat is worn on the upper arm to increase venous dilation. Second, a mark is made on the patient's skin approximately 2 cm cephalad from the junction of the cubital perforator vein (e.g., perforator vein 2) and the proximal radial artery (e.g., artery 4). This junction can be confirmed using ultrasound in the long axis view along the cubital perforator vein. Third, under ultrasound guidance, a needle (e.g., 21g echo-genic needle) can access the radial cutaneous vein (e.g., superficial vein 1) at least approximately 2 cm cephalad from the junction of the cubital perforator vein (e.g., perforator vein 2) and the proximal radial artery (e.g., artery 4). Next, the needle can be percutaneously guided through the septum between the cubital perforator vein (e.g., perforator vein 2) and the proximal radial artery (e.g., artery 4). Fourth, under the transverse ultrasound view, the needle can be advanced from the cubital perforator vein (e.g., perforator vein 2) to the proximal radial artery (e.g., artery 4). Preferably, the advancement angle for advancing the needle into the proximal radial artery is straight on (i.e., the 12 o'clock position).

[0105] Returning to FIG. 15, in some embodiments, implant 13 can be implanted such that a distal implant segment 18 (also referred to herein as an arterial implant segment) is disposed within the radial artery (e.g., artery 4), and a proximal segment 19 (also referred to herein as a venous implant segment) extends through the brachial vein or radial vein (e.g., deep vein 3) and the cubital perforator vein (e.g., perforator vein 2). In some embodiments, the cubital perforator vein (e.g., perforator vein 2) in which implant 13 is implanted has a diameter of at least about 2.5 mm and a length of at least about 10 mm. In some embodiments, the proximal radial artery (e.g., artery 4) in which implant 13 is implanted has a diameter of at least about 2 mm. Also, in some embodiments, the distance between the proximal radial artery (e.g., artery 4) and the cubital perforator vein (e.g., perforator vein 2) is less than about 3 mm. Such a configuration forms an arteriovenous fistula from the proximal radial artery to the cubital perforator vein, which can be beneficial, for example, to patients in need of hemodialysis. The arteriovenous fistula according to some embodiments may, in some cases, be well-suited for patients with a minimum diameter of the smallest proximal radial artery of about 2 mm and a minimum diameter of the cubital perforator vein of about 2.5 mm. The blood flow after implantation of such an implant 13 may be as follows, as described in connection with FIG. 15: The blood flow in the radial artery (e.g., artery 4) enters, from left to right as shown in the figure, the side opening or port of implant 13 (e.g., the side opening or port between the proximal implant segment 19 and the distal implant segment 18), and (i) exits from the distal end of the distal implant segment 18 through the proximal end of the distal implant segment 18 and continues to flow through the artery, or (ii) exits from the proximal end of the proximal implant segment 19 through the distal end of the proximal implant segment 19 and flows into the cubital perforator vein (e.g., perforator vein 2) and the cephalic vein (e.g., superficial vein 1).In some embodiments, and continuing to refer to FIG. 15, after implantation of the implant 13 as described above, blood flow through the brachial vein and / or the radial vein (e.g., the deep vein 3) may be at least partially blocked or completely blocked by the proximal implant segment 19. In some embodiments, the proximal segment 19 that blocks blood flow through the brachial vein and / or the radial vein (e.g., the deep vein 3) can advantageously send more blood through the cephalic vein (e.g., the superficial vein 1), further promoting the growth of the cephalic vein for use in hemodialysis. In some embodiments, the proximal segment 19 of the implant 13 can advantageously send blood directly from the radial artery (e.g., the artery 4) to the cubital perforator vein (e.g., the perforator vein 2) and / or the cephalic vein (e.g., the superficial vein 1), bypassing one or more branch points of the brachial vein and / or the radial vein (e.g., the deep vein 3). In some embodiments, and continuing to refer to FIG. 15, after implantation of the implant 13 as described above, blood flow through the cephalic vein (e.g., the superficial vein 1) can be from right to left and can include venous blood along with the arterial blood provided by the implant 13. Due to the pressure difference between the artery 4 and the perforator vein 2 and / or the superficial vein 1, arterial blood may flow through the proximal implant segment 19 of the implant 13 (i.e., arterial blood is under higher pressure than venous blood, and fluid tends to flow from high pressure to low pressure). The flow of arterial blood in the cephalic vein (e.g., the superficial vein 1) by the implant 13 can advantageously increase at least one of the dimensions (e.g., diameter), thickness, or blood flow rate of the cephalic vein. For example, the flow of arterial blood in the cephalic vein (e.g., the superficial vein 1) by the implant 13 can advantageously increase the diameter of the cephalic vein to at least about 4 mm, at least about 5 mm, or at least about 6 mm. In another example, the flow of arterial blood in the cephalic vein (e.g., the superficial vein 1) by the implant 13 can advantageously set the blood flow in the cephalic vein (e.g., the superficial vein 1) to at least about 400 cc / min, at least about 500 cc / min, or at least about 600 cc / min.In some embodiments, the implant 13 can grow the radial cutaneous vein (e.g., the superficial vein 1) into a single access point for hemodialysis (e.g., for two needles for blood withdrawal and blood return within the same vein). In some embodiments, the implant 13 can grow the radial cutaneous vein (e.g., the superficial vein 1) to a diameter of at least about 6 mm and a blood flow rate of at least about 600 cc / min.

[0106] Referring further to FIG. 15, as described herein, the proximal implant segment 19 may be angled with respect to the distal implant segment 18. In other words, as described herein, in some embodiments, the axis (e.g., the longitudinal axis) of the proximal implant segment 19 may be angled with respect to the axis (e.g., the longitudinal axis) of the distal implant segment 18. The axis of the proximal implant segment may have an angle between about 0 degrees and 90 degrees with respect to the axis of the distal implant segment. In some embodiments, the axis of the proximal implant segment may be angled by about 5 degrees, about 10 degrees, about 15 degrees, about 20 degrees, about 25 degrees, about 30 degrees, about 35 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 55 degrees, about 60 degrees, about 65 degrees, about 70 degrees, about 75 degrees, about 80 degrees, about 85 degrees, or about 90 degrees with respect to the axis of the distal implant segment.

[0107] Further, in addition to FIG. 15, further reference is made to FIGS. 16C, 17A, 17B, 17C, 18A, 18B, 18C, 18D, 19A, 19B, 20A, and 20B, and as already described herein, the implant 13 may include a side opening or port 60 disposed between the proximal implant segment 19 and the distal implant segment 18. The side opening or port 60 may be disposed between the distal end of the proximal implant segment 19 and the proximal end of the distal implant segment 18. As shown in at least some of the figures described above, the side opening or port 60 can be formed by the continuous struts and / or rings 21 of the proximal implant segment 19, the connector struts 20, and the struts forming the proximal end of the distal implant segment 18. In some embodiments, the distal implant segment 18 can be disposed downstream of the distal end of the proximal implant segment 19 (e.g., downstream with respect to the direction of arterial blood flow as shown).

[0108] FIG. 25 schematically shows a portion of the human vasculature representing a potential location 7 for forming an anastomosis (e.g., an AVF) between two blood vessels, such as artery 70 and vein 80, beneath the dermal surface 28, according to some embodiments.

[0109] Figures 26-29 show a method of percutaneously introducing the intravascular guide wire 5 according to some embodiments. The method shown and described in Figures 26-29 may include steps and / or aspects similar to those previously described herein through Figures 2A-2D. As shown in Figures 26-29, the guide wire 5 can be percutaneously introduced by the needle access tool 35 described herein. The needle access tool 35 can include a hollow needle having a proximal port 30 and a distal tip 34 slidably disposed within a sheath 33. The sheath 33 can be connectable to a hub 32 that can include a compression element such as a compression spring 31 disposed between the port 30 and the hub 32. When the port 30 is depressed, the needle tip 34 can be exposed distal to the distal end of the sheath 33 and can penetrate tissue such as skin and blood vessels. When the port 30 is not depressed, the spring 31 extends to move the needle tip 34 proximally and the needle tip 34 is not exposed. In this configuration, the needle access tool 35 can move through the vascular system while reducing the risk of inadvertent puncture and trauma to the vascular system and other tissues. Using this feature of the needle access tool 35 and an appropriate imaging technique such as percutaneous ultrasound, the needle access tool 35 can first be introduced into the artery 70 as shown in Figure 26. With the needle tip 34 retracted within the sheath 33, the needle access tool 35 can be moved to position 7 using an appropriate imaging method as shown in Figure 27. While at position 7, the proximal port 30 can be manipulated (e.g., depressed) to expose the needle tip 34 and then the needle access tool 35 can be advanced to penetrate the vessel wall and the above or any interstitial tissue between the artery 70 and the vein 80 such that the distal end of the sheath 33 enters the lumen of the vein 80. While maintaining this position, the guide wire 5 can be introduced into the proximal port 30 and advanced through the needle access tool 35 such that the distal end of the guide wire 5 can exit the distal end of the needle access tool 35 and enter the lumen of the vein 80 as shown in Figure 28. Figure 29 shows the guide wire 5 having a curvature 6 that can be formed when the guide wire 5 conforms to the anatomical shape of a particular blood vessel after removal of the needle access tool 35.

[0110] Figures 30-40 illustrate a method of percutaneously implanting intravascular implant 13 using delivery device 29, according to some embodiments. Figure 30 shows delivery device 29 disposed on guidewire 5, slid distally along guidewire 5, and with its distal end (e.g., nose cone 8 at the distal end of delivery device 29) passing through dermal surface 28, through artery 70, through the interstitial space between artery 70 and vein 80 or any interstitial space, and into vein 80 (e.g., into the lumen of vein 80). As shown in the figure, implant 13 may be disposed within delivery device 29 in a radially compressed configuration. In some embodiments, proximal implant segment 19 described herein may be disposed within the distal end of delivery device 29 in a radially compressed configuration, and distal implant segment 18 may be disposed within the distal end of delivery device 29 in a radially compressed configuration. However, as shown here and contrary to the implantation methods described throughout Figures 3-15, distal implant segment 18 may be oriented more proximally relative to the distal end of delivery device 29 than proximal implant segment 19 (e.g., implant 13 is oriented opposite to the orientation described throughout Figures 3-15). Thus, as described in connection with Figures 30-40, distal implant segment 18 is referred to as arterial implant segment 18 and proximal implant segment 19 is referred to as venous implant segment 19, but the nomenclature used herein heretofore remains when discussing the distal and proximal ends of the implant segments. Returning to Figure 30, as shown in the figure, implant 13 is disposed on guidewire shaft 22, radially compressed within outer sheath 12, with venous implant segment 19 at least partially disposed within nose cone 8 (e.g., within cavity 9 of nose cone 8), and arterial implant segment 18 (i.e., the distal end of arterial implant segment 18 if maintaining the previous nomenclature) may abut the distal end of intermediate shaft 16.

[0111] Figure 31 shows the nose cone 8 of the delivery device 29 entering the vein 80 across the AVF location 7. Also shown is a gap 14 that can be formed when the delivery device 29 follows the guide wire bend 6 and the nose cone 8 and the outer sheath 12 become non - coaxial. In some embodiments, the gap 14 can be defined as the open space between the proximal opening of the nose cone 8 (e.g., cavity 9), such as the proximal opening of the cavity 9 of the nose cone 8, and the side wall of the outer sheath 12 when the delivery device enters the proximal opening of the nose cone 8. In some embodiments, the length and / or diameter of the gap 14 can be defined as about, at least about, or up to about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% of the respective length and / or diameter of the proximal opening of the nose cone 8 (e.g., cavity 9), or a range including any two of the above values. It should be noted that, as also shown, in order to form the gap 14, the nose cone 8, as shown in Figure 31, for example, (as shown in the figure in some embodiments, the proximal end is angled with respect to the longitudinal length of the nose cone, resulting in) a longer rear proximal end is oriented outwardly of the bend 6. As further shown, the angle 15 between the central axis (e.g., longitudinal axis) of the nose cone 8 and the central axis (e.g., longitudinal axis) of the outer sheath 12 can be formed when the nose cone 8 at the distal end of the delivery device 29 is in the curved configuration as shown in Figure 31 and in the same orientation as when forming the gap 14. In some embodiments, the angle 15 can be, for example, about, at least about, or up to about 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, and a range including any two of the above values. To increase the flexibility between the nose cone 8 and the outer sheath 12, the nose cone 8 may have a slit in the wall forming the cavity 9. In some embodiments, to increase the flexibility between the nose cone 8 and the outer sheath 12, the cavity 9 of the nose cone 8 can be oversized with respect to the outer diameter of the outer sheath 12. In some embodiments, the bend 6 of the guide wire 5 can be utilized to form the angle 15 and the gap 14.Alternative means of forming the angle 15 and the gap 14 are also available. The alternative embodiments may, for example, use one, two, or more pull wires to bias the distal end of the delivery system 29 such that the gap 14 is formed. Depending on the desired clinical outcome, various manipulable and / or biasable elements can be utilized. In some embodiments, such as when the nose cone 8 is configured as described and illustrated with respect to FIG. 22B, the gap 14 may not be formed or may not be necessary.

[0112] FIG. 32 shows the nose cone 8 engaged with the proximal wall of the vein 80 after the delivery device 29 has been pulled proximally from its position in FIG. 31. The engagement of the nose cone 8 (e.g., the proximal end of the nose cone 8) with the proximal wall of the vein 80 may be due to the gap 14 formed when the delivery device 29 is pushed into the curved configuration with the proximal tapered end 11 (e.g., the long posterior proximal end) on the outside of the curve. In some embodiments, the gap 14 is not necessary for the engagement of the nose cone 8 (e.g., the proximal tapered end 11 of the nose cone 8) with the proximal wall of the vein 80. For example, the proximal tapered end 11 of the nose cone 8 may engage the proximal wall of the vein 80 when the delivery device 29 is pulled proximally. Also shown is the deformation of the anatomical structure at the AVF location 7 as a result of the juxtaposition force between the proximal wall of the vein 80 and the proximal tapered end 11 of the nose cone 8. This deformation of the anatomical structure at the AVF location 7 is visualized by ultrasound and can be utilized to confirm proper tissue engagement and / or implant placement prior to delivery.

[0113] Figure 33 shows the first step of the first stage of delivery of a radially compressed (e.g., elastically constrained) implant 13 according to some embodiments. When the nose cone 8 is juxtaposed against the proximal wall of the vein 80, the outer sheath 12 can be retracted proximally to expand the radially compressed implant 13 at the precise position defined by the engagement of the nose cone 8 and the proximal wall of the vein 80. The distal end of the intermediate shaft 16 may be held fixed during retraction of the outer sheath 12 so that the radially compressed implant 13 does not slide proximally during retraction of the outer sheath 12. Also shown is the manner in which the venous implant segment 19, which may occur during retraction of the outer sheath 12, is at least partially constrained by the cavity 9 of the nose cone 8 (e.g., the outer sheath 12 no longer maintains radial compression of the venous implant segment 19, and thus the venous implant segment 19 expands within the cavity 9). In some embodiments, a portion of the venous implant segment 19 (e.g., the distal end, but here facing proximally) that is radially expanding at the AVF location 7 due to the radial stiffness of the implant 13 is also shown. Also shown is the arterial implant segment 18 that remains radially compressed within the outer sheath 12. To retract the outer sheath 12, the control knob 26 of the delivery device 29 can be slid proximally from the most distal position during the initial delivery of the implant 13. At this time, the handle 23 of the delivery device 29 is fixed to maintain the state where the nose cone 8 is juxtaposed against the proximal wall of the vein 80. In some embodiments, the intermediate shaft 16 can be held fixed during retraction of the outer sheath 12 by an intermediate shaft connector 50 whose proximal movement is blocked by interaction with an intermediate shaft connector stop 52 of the delivery device 29.

[0114] FIG. 34 shows the continuation of the delivery of the radially compressed (e.g., elastically constrained) implant 13 according to some embodiments, with the outer sheath 12 further retracted to show the arterial implant segment 18 completely released from the outer sheath 12. As shown in the figure, when the outer sheath 12 is fully retracted, the arterial implant segment 18 can expand radially within the artery 70. When expanding radially within the artery 70, the arterial implant segment 18 can engage radially with the wall of the artery 70. Also, as shown in the figure, in some embodiments, when the outer sheath 12 is fully retracted, the arterial implant segment 18 may be angled with respect to the venous implant segment as described herein (e.g., the longitudinal axis of the arterial implant segment 18 may be angled with respect to the longitudinal axis of the venous implant segment 19). To further retract the outer sheath 12, while the handle 23 of the delivery device 29 holds the nose cone 8 juxtaposed to the proximal wall of the vein 80, the control knob 26 of the delivery device 29 may be slid proximally toward its most proximal position. In some embodiments, the intermediate shaft 16 can be fixedly held during the retraction of the outer sheath 12 by an intermediate shaft connector 50 that is prevented from moving proximally by its interaction with the intermediate shaft connector stop 52 of the delivery device 29. Although the operations of FIGS. 33 and 34 have been described separately, it should be understood that in practice, the operations illustrated and described in FIGS. 33 and 34 can proceed continuously and smoothly. For example, the outer sheath 12 can be fully retracted in a single operation by the movement (e.g., sliding) of the control knob 26 of the delivery device 29 from its initial most distal position to its most proximal position, thereby completely releasing the implant 13 from the outer sheath 12 in a single operation.

[0115] FIG. 35 shows the delivery of a radially compressed (e.g., elastically constrained) venous implant segment 19 according to some embodiments. As shown in the figure, when the nose cone 8 is advanced distally by advancing the guide wire shaft 22 distally (e.g., by advancing the delivery device 29 distally), the venous implant segment 19 is held in place by the connector strut 20 connected to the arterial implant segment 18, thereby being slidably released from the cavity 9 of the nose cone 8. Further still, as shown in the figure, when the venous implant segment 19 is released from the cavity 9, it can expand radially within the vein 80. When expanding radially within the vein 80, the venous implant segment 19 can engage radially with the wall of the vein 80. Also, as shown in the figure, the arterial implant segment 18 may provide means for fixing the most distal part of the distal edge of the venous implant segment 19 (here facing the most proximal part of the proximal edge) so as not to penetrate into the lumen space of the artery 70. Further as shown in the figure, upon radial expansion, the distal end of the venous implant segment 19 (here facing the proximal end) may expand radially against the distal wall of the artery 70 and form a fluid seal with the distal wall of the artery 70. The arterial implant segment 18 can also provide radial support to the artery 70 to ensure the patency and sufficient blood flow of the artery 70 after implantation of the implant 13.

[0116] FIG. 36 shows the first step of removal of the delivery device 29 according to some embodiments, where the outer sheath 12 and the intermediate shaft 16 advance distally through the delivered (e.g., radially expanded) implant 13 into the cavity 9 within the nose cone 8. In some embodiments, the intermediate shaft 16 leads the outer sheath 12 during this advancement step, facilitating secure engagement with the cavity 9 without the outer sheath 12 catching on the proximal end 11 of the nose cone 8. To move / advance the outer sheath 12 distally, the control knob 26 of the delivery device 29 may be moved (e.g., slid) distally to its most distal position within the handle 23 while the handle 23 of the delivery device 29 maintains its position. Further still, in some embodiments, after the control knob 26 has moved (e.g., slid) to its most proximal position from a preceding step of the delivery process, the intermediate shaft connector 50 engages the control knob 26 and the intermediate shaft connector 50 moves distally with the control knob 26 upon distal movement of the control knob 26, whereby the intermediate shaft 16 can be led and advanced together with the outer shaft 12.

[0117] FIG. 37 shows the continuation of removal of the delivery device 29 according to some embodiments, where the delivery system 29 is rotated, e.g., about 180 degrees axially, such that the proximal portion of the proximal tapered end 11 of the nose cone 8 is inside the curvature 6. In this orientation, the gap 14 is minimized, disappears, or substantially disappears such that there can be coplanar contact between the proximal tapered end 11 and the outer sheath 12. This low-profile configuration allows the nose cone 8 to be easily removed without engaging either the delivered implant 13 or the anatomical features near the AVF location 7. In some embodiments, the engagement between the outer sheath 12 and the proximal end of the nose cone 8 can follow that shown and described in relation to FIG. 10B herein. For example, upon distal advancement of the outer sheath 12, the proximal tapered end of the nose cone 8 is received within the lumen of the outer sheath 12, creating a substantially smooth transition between the outer sheath 12 and the proximal end of the nose cone 8, thus assisting in the removal of the delivery device 29.

[0118] Figure 38 shows the continuation of the removal of the delivery device 29 according to some embodiments. As shown in the figure, when the delivery device 29 retracts proximally, the nose cone 8 passes through most of the implant 13 without interference. The implant 13 can have an unconstrained (e.g., radially expanded) delivery inner diameter dimension that is larger than the outer dimensions of the nose cone 8, such that when the nose cone 8 is removed through the implant 13, there is no excessive resistance or interference between the nose cone 8 and the implant 13. In some embodiments, and as described in connection with FIG. 13 of this specification, if a gap 14 is reformed during the retraction of the delivery device 29, the delivery device can be rotated again to minimize and / or eliminate the gap 14 and facilitate the removal of the delivery device 29.

[0119] Figure 39 shows a state in which, according to some embodiments, the delivery device 29 has been completely removed and only the guide wire 5 remains. Prior to removal of the guide wire 5, it may be desirable or advantageous to advance a balloon-expandable catheter of appropriate dimensions relative to the implant 13 and the vasculature to facilitate complete expansion of the implant 13. In some embodiments having different diameter, cross-sectional area, and / or peripheral venous implant segments 19 and arterial implant segments 18, balloon-expandable catheters of different dimensions may be used to facilitate complete expansion of the venous implant segment 19 and the arterial implant segment 18.

[0120] Figure 40 shows the completed delivery of implant 13 with arterial implant segment 18 in artery 70, venous implant segment 19 in vein 80, and venous implant segment 19 forming an AVF between artery 70 and vein 80. As described herein, implant 13 can be at least partially positioned and fixed by any one or more of the following: (i) engagement of the radially expanded arterial implant segment 18 with the wall of artery 70, (ii) engagement of the radially expanded venous implant segment 19 with the wall of vein 80, (iii) engagement of any anatomical structure, such as any portion of the wall of artery 70 and / or vein 80, with any anchor(s) and / or barb(s) (not shown in Figure 40) of implant 13, and (iv) in embodiments where implant 13 includes a continuous strut / ring 21, engagement of the distal wall of artery 70 with the continuous strut / ring 21 (e.g., anastomotic ring) of implant 13. As shown in the figure and described herein, the distal end of venous implant segment 19 (here facing the proximal end) may not occlude the lumen of artery 70. In some embodiments, arterial implant segment 18 can be arranged via connector strut 20 such that the distal end of venous implant segment 19 (here facing the proximal end) does not occlude the lumen of artery 70. In embodiments where implant 13 includes a continuous strut / ring 21, the continuous strut / ring 21 can form a fluid seal with the distal wall of artery 70. As further shown in Figure 40 and described herein, in some embodiments, venous implant segment 19 (e.g., an axis such as the longitudinal axis of the venous implant segment) may have an angle of about 0 degrees to about 90 degrees relative to arterial implant segment 18 (e.g., an axis such as the longitudinal axis of the arterial implant segment). Further, implant 13 may include any one or more of the features, dimensions, characteristics, etc. of any of the embodiments of implant 13 described herein.

[0121] Referring to FIG. 25, before implantation of the implant 13, the blood flow in the artery 70 may be from right to left and the blood flow in the vein 80 may be from left to right. Referring to FIG. 40, after implantation of the implant 13, the blood flow may be as follows: the blood flow in the artery 70 is from right to left and enters the side opening or port 60 of the implant 13 (e.g., the side opening or port between the venous implant segment 19 and the arterial implant segment 18) as shown in the figure, (i) flows through the proximal end of the arterial implant segment 18 (here facing the distal end), exits the distal end of the arterial implant segment 18 (here facing the proximal end), and continues the flow through the artery, and (ii) passes through the distal end of the venous implant segment 19 (here facing the proximal end), exits from the proximal end of the venous implant segment 19 (here facing the distal end), and flows into the vein 80 (and, for example, after exiting the venous implant segment 19, flows from left to right in the vein 80). In some embodiments, still referring to FIG. 40, after implanting the implant 13 as shown in the figure, the blood flow through the vein 80 may be at least partially blocked or completely blocked by the venous implant segment 19 of the implant 13 (e.g., the blood flow from left to right on the left side of the implant 13). Due to the pressure difference between the artery 70 and the vein 80, arterial blood can flow through the venous implant segment 19 of the implant 13. The flow of arterial blood in the vein 80 by the implant 13 can advantageously increase at least one of the dimensions (e.g., diameter), thickness, and blood flow rate of the vein. For example, the flow of arterial blood in the vein 80 by the implant 13 can advantageously increase the diameter of the vein 80 to at least about 4 mm, at least about 5 mm, or at least about 6 mm. In another example, the flow of arterial blood in the vein 80 by the implant 13 can advantageously set the blood flow in the vein 80 to at least about 400 cc / min, at least about 500 cc / min, or at least about 600 cc / min. In some embodiments, the implant 13 can cause the vein 80 to grow into a single access point for hemodialysis.In some embodiments, the implant 13 is capable of growing the vein 80 to a diameter of at least about 6 mm and a blood flow rate of at least about 600 cc / min.

[0122] The methods and apparatuses described through FIGS. 25-40 can be applied to AVF formation in the vasculature of any relevant region of the human body for any purpose, including but not limited to the placement of an access point for hemodialysis. For example, the methods and apparatuses described through FIGS. 25-40 can be applied to AVF formation between the femoral artery and the femoral vein.

[0123] FIG. 41 shows a method of bypassing a portion of an artery using an intravascular implant according to some embodiments. An artery 75 having an arterial bifurcation 77 and an arterial occlusion 79 is shown. Also shown is a vein 85 adjacent to the artery 75, which may include a venous valve 87 in some embodiments. Also shown are two implants 13, one (e.g., the left one) forming an AVF between the artery 75 and the vein 85 on the left side (e.g., upstream side) of the arterial occlusion 79, and one (e.g., the right one) being implanted to form an AVF between the artery 75 and the vein 85 on the right side (e.g., downstream side) of the arterial occlusion 79.

[0124] Before implantation of the implant 13, the blood flow in the artery 75 can flow from left to right, but the normal flow of blood through the artery 75 may be impeded by blockage, substantial blockage, or partial blockage by the arterial occlusion 79. Since the arterial bifurcation 77 is located on the left side (e.g., upstream side) of the arterial occlusion 79, it can receive the blood flow from the artery as shown by the arrow in FIG. 41. Also, before implantation of the implant 13, the blood flow in the vein 85 may flow from right to left, and when the venous valve 87 is present, the blood may flow in the same direction through the venous valve 87.

[0125] As shown in the figure, after implantation of the implant 13, the arterial blood flow can be as follows: The blood flow in the artery 75 is from left to right, through the distal end (by the convention used in this specification) of the arterial segment 18 of the left implant 13, and out from the proximal end (by the convention used in this specification) of the arterial segment 18 of the left implant 13. (i) It may continue to flow through the artery from left to right, either passing through the arterial bifurcation 77 or being blocked by the arterial occlusion 79. (ii) It may also flow through the distal end (by the convention used in this specification) of the venous segment 19, out from the proximal end (by the convention used in this specification) of the venous segment 19, and into the vein 85. As shown in the figure, if a venous valve 87 is arranged in the vein 85 between the left implant 13 and the right implant 13, during or before implantation of the implant, a valvulotome or other device is used to destroy the venous valve 87. Thereby, after implantation of the implant, the arterial blood led from the artery 75 to the vein 85 by the left implant 13 can continue to flow past the (destroyed) venous valve 87. After the arterial blood flow is led into the vein 85 by the left implant 13 and the interfering venous valve 87 is destroyed, the arterial blood flow can continue as follows: The arterial blood flows through the venous implant segment 19 of the left implant 13, then through the vein 85, passing through the destroyed venous valve 87 if any, flowing through the proximal end of the venous implant segment 19 of the right implant 13, out from the distal end of the venous implant segment 19 of the right implant 13, and flowing through the side opening or port 60 of the right implant 13. (i) It may flow leftward towards the arterial occlusion 79 before being blocked by the arterial occlusion 79. (ii) It may flow rightward through the proximal end of the arterial implant segment 18 of the right implant, out from the distal end of the arterial implant segment 18 of the right implant, and continue to flow through the artery 75. Thus, with the use of two implants 13, the arterial blood flow of the artery having the arterial occlusion 79 can be restored. After implantation of the implant 13 as shown in the figure, the venous blood flow in the vein 85 may be blocked by the venous implant segment 19 of the right implant 13, as indicated by the return arrow in FIG. 41.The two implants 13 may be coated with a graft material as described herein to facilitate redirection of blood flow, as discussed in connection with FIG. 41.

[0126] Continuing to refer to FIG. 41, in some embodiments, the venous implant segment 19 of the implant 13 may traverse the venous valve 87 and may not require destruction of the venous valve 87 prior to implantation (e.g., the radial stiffness of the implant may be sufficient to open the venous valve 87 and allow for a desired blood flow through the venous valve 87). In some embodiments, the delivery device 29 has sufficient axial stiffness to traverse the venous valve 87 and allows for implantation of the venous implant segment 19 of the implant 13 to traverse the venous valve 87. In some embodiments, two implants 13 may overlap; for example, the venous implant segment 19 of the left implant may be implanted within the venous implant segment 19 of the right implant, or vice versa. In some embodiments, two implants 13 may be spaced apart, taking into account the anatomical shape of the blood vessel (such as any arterial bifurcation 77) and any arterial occlusion 79. Any of the delivery methods described herein may be used for implantation of multiple implants 13 as shown in FIG. 41. This includes the methods described in connection with FIGS. 1-15 where the delivery device can first access the vein before the artery, and the methods described in connection with FIGS. 25-40 where the delivery device can first access the artery before the vein. Furthermore, as shown and described in connection with FIG. 41, the implant 13 can be used to alter the path of blood flow in the body in multiple ways and is not limited to any one description provided herein.For example, blood flow may enter or exit at the distal end of the distal implant segment 18 (i.e., the arterial implant segment 18), blood flow may enter or exit through a side opening or port between the proximal end of the distal implant segment 18 (i.e., the arterial implant segment 18) and the distal end of the proximal implant segment 19 (the venous implant segment 19), blood flow may enter or exit at the proximal end of the distal implant segment 18 (i.e., the arterial implant segment 18), blood flow may enter or exit at the distal end of the proximal implant segment 19 (i.e., the venous implant segment 19), and blood flow may enter or exit at the proximal end of the proximal implant segment 19 (i.e., the venous implant segment 19).

[0127] As described herein, the delivery system 29 can be used compatibly with the delivery device 29. Also, as described herein, the distal implant segment 18 can be used compatibly with the arterial implant segment 18. Also, as described herein, the proximal implant segment 19 can be used compatibly with the venous implant segment 19. In some embodiments, the delivery device 29 can be configured to deliver the implant 13 to the patient percutaneously. In some embodiments, the delivery device 29 can be configured to deliver the implant 13 into the patient after performing a surgical resection up to and / or in the vicinity of the location of the AVF.

[0128] FIG. 42 shows an embodiment of a reaction force mechanism 100 configured to apply a reaction force F to the patient's skin / dermal surface 28 during implantation of the implant 13. The reaction force mechanism can, for example, apply a reaction force to the patient when retracting the outer sheath 12 proximally relative to the nose cone 8, to assist in maintaining the engagement of the most proximal tip 63 / proximal tapered end 11 of the nose cone 8 with the venous or arterial wall while releasing the proximal implant segment from the outer sheath 12. The reaction force mechanism 100 can be configured in various ways and can interact with the delivery device 29. For example, the reaction force mechanism 100 can comprise a generally tubular body that can be disposed around the outer sheath 12 and apply a force F between the distal end (e.g., the handle nose cone 27 or near it) of the handle 23 of the delivery device 29 described herein and the patient's skin / dermal surface 28. In some embodiments, the reaction force mechanism 100 can slide over the distal end of the delivery device 29 (e.g., over the nose cone 8 and the outer sheath 12) before implanting the implant 13. In some cases, the reaction force mechanism 100 can be configured with two or more parts that can be coupled to each other on the outer sheath 12 at any point during the implanting step of the implant 13 and / or as needed. In other embodiments, the reaction force mechanism 100 can include a longitudinal slit / aperture sized to receive the outer sheath 12 and / or have a longitudinal slit / aperture and be deformable to place the reaction force mechanism 100 on the outer sheath 12 at any point during the implanting step of the implant 13 and / or as needed. For example, the reaction force mechanism 100 can include a tube structure that can deform longitudinally to provide a reaction force F to the patient's skin / dermal surface 28 when the reaction force mechanism 100 abuts against the distal end of the handle 23 of the delivery device 29 and the patient's skin / dermal surface 28. Such a configuration (e.g., a deformable tube structure) can be customized as needed (e.g., by cutting the tube to an appropriate length based on the length of the outer sheath 12 remaining outside the patient, such that the tube deforms to a dimension slightly longer than the exposed outer sheath 12 so as to be able to apply such a reaction force F). As another example, the reaction force mechanism 100 can include a spring (e.g., a coil spring) capable of providing the reaction force F.In some embodiments, the reaction force mechanism 100 can include one or more features, such as a flange or (one or more) protrusions, whose outer diameter size increases at a location in contact with the skin / dermal surface 28, capable of dispersing the reaction force F with respect to the skin / dermal surface 28.

[0129] The foregoing description and examples are presented solely for the purpose of illustrating the present disclosure and are not intended to be limiting. Each of the disclosed aspects and embodiments of the present disclosure can be considered individually or in combination with other aspects, embodiments, and variations of the present disclosure. Additionally, unless otherwise specified, any step of the methods of the present disclosure is not limited to a particular order of execution. Modifications of the disclosed embodiments that embody the spirit and gist of the present disclosure can be conceived by those skilled in the art, and such modifications are within the scope of the present disclosure.

[0130] The terms related to orientation used herein, such as "upper", "lower", "horizontal direction", "vertical direction", "longitudinal direction", "width direction", "end", are used in the context of the described embodiments. However, the present disclosure is not limited to the described orientation. In fact, other orientations are possible and within the scope of the present disclosure. Terms related to circular shapes such as diameter and radius used herein are not required to refer to a complete circular structure, but rather are understood to apply to any suitable structure having a cross-sectional area that can be measured in the lateral direction. General shape-related terms such as "circular", "cylindrical", "semi-circular", "semi-cylindrical", or related or similar terms do not necessarily need to strictly conform to the mathematical definitions of structures such as circles and cylinders, and can include moderately approximated structures.

[0131] In particular, conditional language used in this specification such as "can", "might", "may", "e.g." is generally intended to convey that, unless otherwise specified or unless otherwise indicated within the context in which it is used, some embodiments include certain features, elements, and / or states and other embodiments do not. Thus, such conditional language is not generally intended to mean that one or more features, elements, blocks, and / or states are required in some form in one or more embodiments, or that one or more embodiments necessarily include logic for determining whether these features, elements, and / or states are included in or are to be performed in any particular embodiment, regardless of the presence or absence of author input or prompting.

[0132] Conjunctive phrases such as "at least one of X, Y, and Z" are understood in the context in which they are generally used to convey that an item, term, etc. is any one of X, Y, or Z, unless otherwise specified. Thus, such conjunctive phrases are not generally intended to mean that a particular embodiment requires the presence of at least one of X, at least one of Y, and at least one of Z.

[0133] As used herein, the terms "approximately", "about", and "substantially" represent an amount close to the recited amount that achieves the desired function or achieves the desired result. For example, in some embodiments, depending on the context, the terms "approximately", "about", and "substantially" refer to an amount within 10% of the recited amount. The term "generally" as used herein represents a value, amount, or characteristic that mainly includes or tends to approach a particular value, amount, or characteristic. As an example, in certain embodiments, depending on the context, the term "generally parallel" can refer to a deviation of up to 20 degrees from an exactly parallel state.

[0134] When the term "about" is used in front of a range of two numerical values, this is intended to include, in addition to the range from the specified first value to the specified second value, the range between about the first value and about the second value.

[0135] Unless otherwise expressly stated, articles such as "a" or "an" should generally be construed as including one or more of the recited items. Thus, expressions such as "an apparatus configured to..." are intended to include one or more of the recited apparatuses. Such one or more recited apparatuses may be collectively configured to perform the stated recitation. For example, "a processor configured to perform recitations A, B, and C" can include a first processor configured to perform recitation A in cooperation with a second processor configured to perform recitations B and C.

[0136] The terms "comprising", "including", "having", etc. are synonyms and are used in an inclusive and open-ended manner and do not exclude additional elements, features, acts, operations, etc. Similarly, the terms "some", "certain", etc. are synonyms and are used in an open-ended manner. Also, since the term "or" is used in an inclusive sense (not in an exclusive sense), for example, when used to combine recited elements, the term "or" means one, some, or all of the elements in the list.

[0137] Overall, the language of the claims should be construed broadly based on the language used in the claims. The language of the claims is not limited to the non-exclusive embodiments and examples illustrated and described in this disclosure or discussed in the examination procedure of this application.

[0138] Intravascular implants and systems, devices, and methods for their accurate placement have been disclosed in the context of specific embodiments and examples. However, the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses of the embodiments, as well as to their specific modifications and equivalents. The various features and aspects of the disclosed embodiments can be combined with or substituted for one another to form various aspects of intravascular implants and systems, devices, and methods for their accurate placement. The scope of the present disclosure should not be limited to the specific disclosed embodiments described herein.

[0139] The specific features described in individual embodiments of the present disclosure can also be implemented in combination in a single embodiment. Conversely, the various features described in a single embodiment can also be implemented separately, or in any suitable sub-combination, in multiple embodiments. Although features may be described herein as acting in specific combinations, in some cases one or more features of the claimed combination may be removed from the combination, and the combination can be claimed as any sub-combination or variation of any sub-combination.

[0140] The methods and apparatuses described herein may be capable of various modifications and alternative forms, and specific examples thereof are shown in the drawings and described in detail herein. However, the present invention is not limited to the specific forms or methods disclosed, and conversely, the present invention is understood to encompass all modifications, equivalents, and alternatives included within the spirit and scope of the various embodiments described and the appended claims. Further, the disclosure herein of any specific feature, aspect, method, characteristic, trait, attribute, element, etc. associated with an embodiment can be used in all other embodiments defined herein. Any method disclosed herein need not be executed in the order described. Depending on the embodiment, one or more operations, events, or functions of any of the algorithms, methods, or processes described herein can be executed in a different order, can be added, combined, or completely omitted (e.g., not all of the described operations or events are necessary for the practice of the algorithm). In some embodiments, operations or events can be executed simultaneously rather than sequentially, for example, through multi-threaded processing, interrupt processing, or across multiple processors or processor cores, or on other parallel architectures. Further, no element, feature, block, or step, or group of elements, features, blocks, or steps is essential to every embodiment. Further, all possible combinations, sub-combinations, and rearrangements of systems, methods, features, elements, modules, blocks, etc. are within the scope of this disclosure. Also, the use of words indicating order or time sequence such as "then," "next," "after," "subsequently," etc. is generally intended to smooth the flow of the text and is not intended to limit the order of the operations performed, unless otherwise specified or understood from the context in which they are used. Thus, some embodiments may be executed in accordance with the order of operations described herein, while other embodiments may be executed in accordance with a different order of operations.

[0141] Furthermore, operations may be shown in the drawings or described in the specification in a particular order, but such operations need not be performed in the particular order shown or in a sequential order, and not all operations need to be performed to obtain a desired result. Other operations not shown or described can also be incorporated into the exemplary methods and processes. For example, one or more additional operations can be performed before, after, simultaneously with, or between any of the described operations. Further, in other embodiments, the arrangement or order of the operations can be changed. Also, the separation of various system components in the embodiments described herein should not be understood to require such separation in all embodiments, and it should be understood that the described components and systems can generally be integrated in a single product or packaged in multiple products. Further, other embodiments are within the scope of the present disclosure.

[0142] Some embodiments have been described in connection with the accompanying drawings. The particular figures are drawn and / or shown to scale, but such scale is not limiting. Other dimensions and proportions than those shown are envisioned and are within the scope of the embodiments disclosed herein. Distances, angles, etc. are illustrative only and do not necessarily maintain an exact relationship to the actual dimensions and layout of the illustrated apparatus. Components can be added, deleted, and / or rearranged. Further, the disclosure herein of any particular feature, aspect, method, characteristic, trait, quality, attribute, element, etc. associated with the various embodiments can be used in all other embodiments defined herein. Further, any method described herein can be implemented using any apparatus suitable for performing the described steps.

[0143] The methods disclosed herein can include particular actions performed by an operator, but the methods can also include, either explicitly or implicitly, the act of any third party instructing those actions. For example, an action such as "positioning an electrode" includes "instructing the positioning of the electrode".

[0144] In summary, various embodiments and examples related to intravascular implants and devices and methods for accurate placement have been disclosed. Although intravascular implants and systems, devices and methods for their accurate placement have been disclosed in the context of those embodiments and examples, the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or other uses of the embodiments, as well as specific modifications and equivalents thereof. The present disclosure is expressly intended that various features and aspects of the disclosed embodiments can be combined with each other or can be substituted for each other. Accordingly, the scope of the present disclosure should not be limited by the specific disclosed embodiments described herein, but should be determined only by a fair interpretation of the claims that follow.

[0145] Also, the scope disclosed herein includes any overlaps, subranges, and combinations thereof. Terms such as "up to", "at least", "greater than", "less than", "between", etc. include the recited numbers. Terms such as "about" or "approximately" preceding a number include the recited number and should be interpreted based on the context (e.g., should be interpreted as accurately as reasonably possible in the context. For example, ±5%, ±10%, ±15%, etc.). For example, "about 1V" includes "1V". Phrases preceded by terms such as "substantially" include the recited phrase and should also be interpreted based on the context (e.g., within a reasonable range possible in that context). For example, "substantially perpendicular" includes "perpendicular". Unless otherwise specified, all measurements are under standard conditions including temperature and pressure.

Claims

1. An implant configured to be delivered percutaneously to the patient's arm for arteriovenous fistula formation, The proximal implant segment consists of a proximal end, a distal end, and an axis extending through them, A distal implant segment connected to the proximal implant segment, comprising a proximal end, a distal end, and an axis extending through them, The lateral opening between the distal end of the proximal implant segment and the proximal end of the distal implant segment, Equipped with, An implant in which the proximal implant segment is configured to bend or curve by more than 90 degrees relative to the distal implant segment in a direction away from the lateral opening.

2. The implant according to claim 1, wherein the lateral opening is configured to allow blood to flow through the lateral opening in (i) a first direction along the proximal implant segment toward the proximal end of the proximal implant segment, and (ii) a second direction along the distal implant segment toward the distal end of the distal implant segment.

3. The implant according to claim 1 or claim 2, wherein the proximal implant segment is bendable or curved by at least 180 degrees in a direction away from the lateral opening relative to the distal implant segment.

4. The implant according to claim 1 or 2, wherein the proximal implant segment comprises a series of strut rows substantially circumferentially arranged around the axis of the proximal implant segment, and the series of strut rows of the proximal implant segment are interconnected by one or more axially extending struts substantially aligned along the axis of the proximal implant segment.

5. The implant according to claim 4, wherein the adjacent strut rows of the proximal implant segment are connected by a single axially extending strut.

6. The implant according to claim 4, wherein each strut row is composed of a row of wavy struts.

7. The implant according to claim 4, wherein the distal implant segment comprises a series of strut rows arranged at least partially circumferentially around the axis of the distal implant segment, and the series of strut rows of the distal implant segment are interconnected by one or more axially extending struts arranged substantially along the axis of the distal implant segment.

8. The implant according to claim 7, wherein the series of strut rows of the distal implant segment are interconnected by at least one more axially extending strut than the series of strut rows of the proximal implant segment, in order to provide greater flexibility to the proximal implant segment than to the distal implant segment.

9. The implant according to claim 4, wherein the majority or all of the one or more axially extending struts of the proximal implant segment are located on the side of the proximal implant segment that aligns with the position of the lateral opening.

10. The implant according to claim 1 or claim 2, wherein the proximal implant segment has greater flexibility than the distal implant segment.

11. The implant according to claim 1 or claim 2, wherein the proximal implant segment comprises a tubular body having a flow channel lumen extending between its proximal end and distal end.

12. The implant according to claim 1 or claim 2, wherein the proximal implant segment is linear.

13. The implant according to claim 1 or 2, wherein the distal implant segment comprises at least a partially tubular body extending between its proximal end and its distal end.

14. The implant according to claim 1 or claim 2, wherein the distal implant segment comprises a tubular body having a flow channel lumen extending between its proximal end and its distal end.

15. The implant according to claim 1 or claim 2, wherein the distal implant segment is linear.

16. The implant according to claim 1 or 2, wherein the proximal implant segment and the distal implant segment each comprise an expandable body, and the proximal implant segment is oriented at an angle to the distal implant segment when the proximal and distal implant segments are fully expanded in a stationary configuration.

17. The implant according to claim 1 or claim 2, wherein the axial length of the proximal implant segment is greater than the axial length of the distal implant segment.

18. The implant according to claim 1 or claim 2, wherein the distal end of the proximal implant segment includes an anastomotic ring.

19. The implant according to claim 1 or claim 2, wherein one or both of the proximal implant segment and the distal implant segment are provided with one or more anchors configured to fix one or both segments to the wall of a vein or artery.

20. The implant according to claim 1 or claim 2, wherein one or both of the proximal implant segment and the distal implant segment are covered with graft material.

21. The implant is folded into a folded configuration for percutaneous delivery into the patient's arm, and expands from the folded configuration into an expanded configuration for implantation between the patient's vein and artery. An implant according to claim 1 or claim 2, configured in such a way.

22. The implant according to claim 1 or claim 2, wherein the proximal implant segment and the distal implant segment are formed from a single, integral piece.

23. The implant according to claim 1 or claim 2, wherein the proximal implant segment and the distal implant segment are provided with a metal frame.

24. The implant according to claim 1 or claim 2, wherein the proximal implant segment and the distal implant segment are formed from a single laser-cut hypotube.

25. The implant according to claim 1 or claim 2, further comprising one or more axially extending struts connecting the distal end of the proximal implant segment to the proximal end of the distal implant segment.

26. A portion of the distal edge of the proximal implant segment is at an angle with respect to the axis of the proximal implant segment and forms a portion of the lateral opening, The implant according to claim 1 or claim 2, wherein the portion of the distal edge of the proximal implant segment having an angle with respect to the axis of the proximal implant segment is provided with one or more proximal-oriented anchors extending toward the proximal end of the proximal implant segment.

27. ​​The implant according to claim 26, wherein the proximal implant segment comprises one or more distally oriented anchors extending toward the distal end of the proximal implant segment.

28. An implant configured to be delivered percutaneously to a patient's arm for arteriovenous fistula formation, The proximal implant segment consists of a proximal end, a distal end, and an axis extending through them, A distal implant segment connected to the proximal implant segment, comprising a proximal end, a distal end, and an axis extending through them, It comprises a lateral opening between the distal end of the proximal implant segment and the proximal end of the distal implant segment, A portion of the distal edge of the proximal implant segment is at an angle with respect to the axis of the proximal implant segment and forms a portion of the lateral opening. The portion of the distal edge of the proximal implant segment, which is at an angle with respect to the axis of the proximal implant segment, is provided with one or more proximal-facing anchors that extend toward the proximal end of the proximal implant segment. The implant comprises a proximal implant segment having one or more distally oriented anchors extending toward the distal end of the proximal implant segment.

29. The implant according to claim 28, wherein the proximal implant segment is configured to bend or curve by more than 90 degrees relative to the distal implant segment in a direction away from the lateral opening.

30. The implant according to claim 28, wherein the proximal implant segment is bendable or curved by at least 180 degrees in a direction away from the lateral opening relative to the distal implant segment.

31. The implant according to any one of claims 28 to 30, wherein the proximal implant segment has greater flexibility than the distal implant segment.

32. The implant according to any one of claims 28 to 30, wherein the distal end of the proximal implant segment includes an anastomotic ring.

Images