stents

Abstract

To provide medical devices for facilitating the flow of fluids and materials in and / or between adjacent body lumens.SOLUTION: The present disclosure relates generally to the field of medical devices. In particular, the present disclosure relates to medical devices for facilitating the flow of fluids and materials in and / or between adjacent body lumens, e.g., a stent which maintains an open flow passage between the body lumens. In one example, a stent may comprise an elongate body configured to be expandable between a first constrained configuration and a second unconstrained configuration. In the unconstrained configuration, the body may have a first retention member, a second retention member, and a cylindrical saddle region defining a lumen extending along a longitudinal axis therebetween. The first retention member or the second retention member, or both, may comprise a double-walled flange with an axially inward wall and an axially outward wall, where a portion of the inward wall bends towards a vertical center plane of the saddle region along the longitudinal axis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates generally to the field of medical devices. In particular, the present disclosure relates to medical devices for facilitating the flow of fluids and materials between adjacent body lumens, such as stents that maintain an open flow path between or within body lumens. [Background technology]

[0002] The placement of a self-expanding stent (e.g., a self-expanding metallic stent or SEMS) within an anatomical region (e.g., a body lumen, passageway, vessel, duct, etc.) can allow communication from one region to another. For example, the stent can allow the flow of materials from one body lumen to another.

[0003] However, available stents may have various drawbacks: for example, they may be prone to displacement or migration from a desired placement, such as in response to forces generated by patient movement, or they may not provide sufficient or excessive retention force for a given use.

[0004] Thus, a variety of beneficial medical results may be achieved with the devices and / or methods of the present disclosure. Summary of the Invention

[0005] In one aspect, a stent may include an elongate body configured to be expandable between a first constrained configuration and a second, unconstrained configuration. The elongate body in the unconstrained configuration may include a first retention member, a second retention member, and a cylindrical saddle region extending along a longitudinal axis therebetween. The cylindrical saddle region may define a lumen extending along the longitudinal axis. The first retention member, the second retention member, or both may include a double-walled flange having an axially inner wall, an axially outer wall, and a radially outermost edge extending therebetween. At least a portion of the inner wall may bend along the longitudinal axis toward a vertical center plane of the cylindrical saddle region.

[0006] In this and other aspects of the present disclosure, the inner and outer walls of the first and second retention members, or both, may have non-parallel surfaces. At least a portion of the outer wall may bend away from the vertical center plane of the cylindrical saddle region along the longitudinal axis. The outer wall may have a recess that bends away from the vertical center plane of the cylindrical saddle region along the longitudinal axis. The inner and outer walls, or both, may have straight edges. The inner wall may have a convex portion that bends away from the vertical center plane of the cylindrical saddle region along the longitudinal axis. The outer wall may have a convex portion that bends toward the vertical center plane of the cylindrical saddle region along the longitudinal axis. The axially outermost edge of the first and second retention members, or both, may extend away from the vertical center plane of the cylindrical saddle region to a lip. The lip may define a lumen of the double-walled flange. The flange lumen may be adjacent to the lumen of the cylindrical saddle region. The lip may have an inner diameter of the flange lumen that is equal to or greater than the inner diameter of the cylindrical saddle region lumen. The radially outermost edge may have a diameter greater than the diameter of the cylindrical saddle region. The radially outermost edge may comprise a cylindrical portion parallel to the longitudinal axis. An inner radius of curvature between the inner wall and the radially outermost edge may be greater than, equal to, or less than an inner radius of curvature between the radially outermost edge and the outer wall. The radially outermost edge may be offset from a vertical plane along the longitudinal axis between the beginning of the inner wall and the end of the outer wall. The elongate body may comprise a braid of one or more wires. The stent may comprise a circumferential covering extending completely or partially along the length of the elongate body.

[0007] In one aspect, a stent can include a tubular structure having a constrained configuration and an expanded configuration. The tubular structure in the expanded configuration can include a first end of the tubular structure expanded into a first double-walled flange, a second end of the tubular structure expanded into a second double-walled flange, and a central region extending along a longitudinal axis therebetween. center The region may define a lumen extending along the longitudinal axis. The first double-walled flange or the second double-walled flange, or both, may include an axially inner wall and an axially outer wall. At least a portion of the inner wall extends from the center along the longitudinal axis. center The cross-sectional profile of the first double-walled flange or the second double-walled flange, or both, along a plane parallel to the longitudinal axis may be asymmetric.

[0008] In this and other aspects of the present disclosure, the inner and outer walls of the first retention member or the second retention member, or both, may have non-parallel surfaces. center a first curved portion curving toward the vertical center plane of the region, the inner wall curving toward the center along the longitudinal axis; center The inner wall may have a second curved portion that bends away from the vertical central plane of the region, or the inner wall may have both the first curved portion and the second curved portion. The inner wall or the outer wall, or both, may have straight edges.

[0009] In one aspect, a stent may comprise a cylindrical body having a restrained configuration and an expanded configuration. In the expanded configuration, the cylindrical body may comprise a first retention member, a second retention member, and a saddle region extending along a longitudinal axis between the first retention member and the second retention member. The saddle region may define a lumen extending along the longitudinal axis. The first retention member, the second retention member, or both may comprise a double-walled flange including an axially inner wall and an axially outer wall. At least a portion of the inner wall may bend along the longitudinal axis toward a vertical center plane of the saddle region. The inner wall and the outer wall of the first retention member, the second retention member, or both may comprise non-parallel surfaces.

[0010] In this and other aspects of the present disclosure, the inner wall may include a first curved portion that bends along the longitudinal axis toward the vertical center plane of the saddle region, a second curved portion that bends along the longitudinal axis away from the vertical center plane of the saddle region, or both the first and second curved portions. In this and other aspects of the present disclosure, the same or different inner and outer wall features may be applied to the double-walled flanges of the first retention member, the second retention member, or both. That is, a stent according to aspects of the present disclosure may have double-walled flanges on either or both of the first and second retention members, and the axial inner and outer walls of the flanges may be configured similarly or differently when occurring for both retention members. [Brief explanation of the drawings]

[0011] Non-limiting examples of the present disclosure are described with reference to the accompanying drawings, which are schematic and not intended to be drawn to scale. In the drawings, identical or nearly identical components shown in each are generally designated by a single numeral. For purposes of clarity, not every component is labeled in every drawing, and not every component in every embodiment of the present disclosure is shown, unless the drawings are necessary for those skilled in the art to understand the disclosure.

[0012] [Figure 1] 1 shows a side view of a medical device according to one or more embodiments described herein. [Figure 2] 1 shows a cross-sectional view of a medical device according to one or more embodiments described herein. [Figure 3A] 10 illustrates an alternative retaining member configuration according to various embodiments described herein. [Figure 3B] 10 illustrates an alternative retaining member configuration according to various embodiments described herein. [Figure 3C] 10 illustrates an alternative retaining member configuration according to various embodiments described herein. [Figure 3D] 10 illustrates an alternative retaining member configuration according to various embodiments described herein. [Figure 3E] 10 illustrates an alternative retaining member configuration according to various embodiments described herein. [Figure 3F] 10 illustrates an alternative retaining member configuration according to various embodiments described herein. [Figure 4] 1 illustrates aspects of delivery of a medical device according to one or more embodiments described herein. [Figure 5] 1 illustrates a medical device being placed within tissue, according to one or more embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present disclosure is not limited to the specific embodiments described. The terminology used herein is intended only to describe specific embodiments and is not intended to limit the scope beyond the scope of the appended claims. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs.

[0014] Although embodiments of the present disclosure are described with specific reference to medical devices (e.g., stents, etc.) and systems for drainage of the gallbladder, pseudocyst, and / or gastrojejunostomy, etc., it should be understood that such medical devices may be used in a variety of medical procedures (e.g., external biliary drainage diversion, enteroenteroanastomosis, gastroduodenostomy, gastroileostomy, etc.) to establish and / or maintain a temporary or permanent open flow path or drainage passageway from or between various body organs, lumens, ducts, vessels, fistulas, cysts, and spaces (e.g., dermis, stomach, duodenum, jejunum, small intestine, gallbladder, kidney, pancreas, biliary / pancreatic tree, bladder, ureter, abscess, encapsulated pancreatic necrosis (WOPN), bile duct, etc.). The devices may be inserted via different access points and approaches, for example, percutaneously, endoscopically, laparoscopically, or some combination thereof. While the medical devices disclosed herein are self-expanding, in other embodiments, the medical devices may be expandable by other means, including, for example, by a balloon catheter. Additionally, such medical devices may facilitate access to organs, blood vessels, or body lumens for other purposes, including but not limited to drainage, such as creating a passageway to divert or route fluids or solids from one location to another, removing obstructions, and / or delivering therapy, including non-invasive or minimally invasive manipulation of tissue within an organ and / or introducing a drug through an open channel.

[0015] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the content clearly dictates otherwise. It will be further understood that the terms "comprises" and / or "comprising" or "includes" and / or "including," as used herein, indicate the presence of stated features, regions, steps, elements, and / or components, but do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0016] As used herein, the term "distal" refers to the end of the device that is farthest from the medical professional when introducing the device into a patient, and the term "proximal" refers to the end of the device that is closest to the medical professional when introducing the device into a patient.

[0017] In embodiments, the present disclosure relates to medical devices (e.g., self-expanding metal stents and / or duodenal exclusion devices, etc.) configured to extend between a first body lumen and a second body lumen, assist in apposition or maintaining apposition of the respective layers (e.g., muscular layers) of each body lumen, and establish a temporary, long-term, or permanent open flow path or access passage therebetween. As described herein, one or both of the first and second retention members at opposite ends of the stent, such as flanges, may be double-walled and may include one or more non-vertical surfaces on the axially inner and axially outer walls of the flanges, the walls being oriented relative to a cylindrical saddle region extending along a longitudinal axis between the flanges. Such a configuration of non-vertical surfaces may reduce migration of the medical device relative to tissue(s) between the first and second body lumens, for example, when compared to a corresponding retention member having only vertical surfaces. Additionally or alternatively, retention members such as double-walled flanges having one or more non-vertical surfaces may be configured to provide more control over the resistance of the device to being withdrawn from its planned position once deployed, e.g., resulting in a higher withdrawal force compared to a corresponding retention member having vertical surfaces. For example, a double-walled flange having a non-vertical surface may provide a withdrawal force of greater than 4N, 4.5N, 5N, 5.25N, 5.5N, 5.75N, or 6N (e.g., 4.1N, 4.2N, 4.3N, 4.4N, 4.5N, 4.6N, 4.7N, 4.8N, 4.9N, 5.0N, 5.1N, 5.2N, 5.3N, 5.4N, 5.5N, 5.6N, 5.7N, 5.75N, 5.8N, 5.9N). , 6.0N, 6.1N, 6.2N, 6.3N, 6.4N, 6.5N, 6.6N, 6.7N, 6.8N, 6.9N, 7.0N, 7.1N, 7.2N, 7.3N, 7.4N, 7.5N, 7.6N, 7.7N, 7.8N, 7.9N, 8.0N, 8.1N, 8.2N, 8.3N, 8.4N, 8.5N, 8.6N, 8.7N, 8.8N, 8.9N, or 9.0N pull-out force).In various embodiments, one or more non-vertical surfaces may also be configured to interact less traumatically with at least one tissue wall within the first and second body lumens (e.g., comprising an interior with a smaller surface area of ​​tissue contact points) compared to a vertical surface or another surface having at least one tissue-engaging element, such as a prong, barb, hook, or other similar design.

[0018] The non-vertical surfaces of a medical device, such as a stent, having a retention member with double-walled flange axially inner and outer walls may comprise one or more curved, straight, or angular sections, or any combination thereof, each of which may have the same or different length, angle, inner radius of curvature, directionality, inner angle, or other characteristic relative to another section. The surfaces of the first and second retention members may be the same or different. For example, each end of the medical device may be designed to improve the strength of the medical device (e.g., resistance to pull-out or retention strength, or resistance to radial compression or radial strength) and provide a desired amount of linear apposition force when positioned across a tissue plane. The flange shape may comprise, for example, one or more rolls and / or structural folds to create a double-walled flange structure. In various embodiments, the flange shape may comprise multiple inflection points, which may be points of curvature where a change in the direction of bending occurs.

[0019] Medical devices, such as stents, can be formed from one or more filaments and / or surfaces. In various embodiments, one or more metal wires, one or more wire braids, polymer filaments, sheets, or combinations thereof can form the medical device. For example, lengths of one or more wire braids can form the medical device. The medical device can include one or more structural elements, such as struts, hoops, meshes, tessellated cells, or other units. In many embodiments, the medical device can comprise a mesh, weave, and / or knit surface. In various embodiments, the medical device can be formed from a shape memory material, such as Nitinol.

[0020] Various embodiments of the medical devices described herein may include a complete or partial covering, coating, or other film on the interior of the device, on the exterior of the device, extending between structural elements, or any combination thereof. For example, the covering, coating, or other film may comprise a silicone, a polymer, or a combination thereof. For example, the covering may comprise polyurethane, polytetrafluoroethylene, expanded polytetrafluoroethylene, polyvinylidene fluoride, aromatic polycarbonate-based thermoplastic urethane, and / or other similar materials. The covering may be applied by dip coating, roll coating, painting, spraying, other known processing methods, or a combination thereof. The covering, coating, or other film may inhibit tissue in-growth and / or minimize fluid leakage from the interior and / or exterior of the medical device.

[0021] The covering, coating, or other film may extend completely or partially over the medical device. For example, the first retention member, the second retention member, the saddle region extending between the first and second retention members, or a combination thereof, may comprise a solid covering, a porous covering, or other configuration of covering. In some embodiments, such as when a stent has a cylindrical saddle region and double-walled flanges, such as the first and second retention members, a circumferential covering or coating may be applied to cover the entire length of the stent or a portion of the length of the stent. For example, a partial coating may cover the entire length of the saddle region but not the flanges. The embodiments are not limited herein.

[0022] Various embodiments described herein may include one or more additional features designed to engage at least one tissue layer. For example, embodiments may include one or more textured surfaces, prongs, or other tissue-engaging elements along the first retention member, the second retention member, or any combination thereof.

[0023] Referring to FIG. 1 , in one embodiment, a stent of the present disclosure can include an elongate body or tubular structure 110 that defines a lumen and has a first portion, a second portion, a length, and a diameter. The elongate body 110 can be covered, uncovered, or a combination thereof. The elongate body 110 can include a constrained configuration (e.g., an unexpanded or delivery configuration, not shown) and an expanded or unconstrained configuration (e.g., a shortened or deployed configuration, as shown in FIG. 1 ). The elongate body can be configured to be expandable between the constrained and unconstrained configurations. In the unconstrained configuration, the first portion 112 of the elongate body is radially expandable into the first retention member 114, and the distal portion 122 of the elongate body is radially expandable into the second retention member 124. In some embodiments, the elongate body 110 in the constrained configuration can have a diameter ranging from 2 mm to 6 mm, or from 3 mm to 5 mm. For example, the stent may have a diameter of 10 Fr (3.3 mm) or 3.5 mm in the constrained configuration. In some embodiments, the elongate body 110 in the constrained configuration may have a length ranging from 40 mm to 150 mm. For example, the stent in the constrained configuration may have a length ranging from 40 mm to 100 mm. In some embodiments, the stent in the constrained configuration may have a length ranging from 40 mm to 80 mm.

[0024] The central region can extend between the retention members along the longitudinal axis of the stent. For example, as shown in FIG. 1 , the central region can comprise a cylindrical saddle region 128 extending along the longitudinal axis of the stent between the first retention member 114 and the second retention member 124. The cylindrical saddle region 128 can comprise a tubular or cylindrical structure defining or comprising a lumen or similar structure extending therethrough along the longitudinal axis. The cylindrical saddle region 128 can have a length and a diameter. In embodiments in which the stent has double-walled flanges, with the first and second retention members having axially inner and outer walls and a portion of the inner wall bending toward the vertical center plane of the stent, the length of the cylindrical saddle region can be measured as (i) the length along the elongate body between the beginning of the inner wall of each of the flanges, or (ii) the length along the body that is the shortest distance between the flanges at any point along the inner wall when the stent is expanded, or (iii) the length along the body that is the shortest distance between the flanges at any point along the inner wall when the stent is expanded and deployed in tissue. In many embodiments, a cylindrical saddle region that meets conditions (i) through (iii) above can have a length in the range of 5 mm to 150 mm in the expanded configuration, although in some instances, a cylindrical saddle region (such as region 128 in FIGS. 1 and 2) can have a length in the range of 5 mm to 35 mm in the expanded configuration. Exemplary lengths of the cylindrical saddle region of the device for gastrointestinal stent placement or drainage in the expanded configuration may include lengths in the range of 10 mm to 30 mm, 15 mm to 20 mm, 10 mm to 20 mm, 10 mm to 15 mm, or 5 mm to 10 mm.

[0025] In many embodiments, the diameter of the cylindrical saddle region in the expanded configuration can be larger than the diameter of the elongate body in the constrained configuration. For example, the diameter of the cylindrical saddle region (such as region 128 in FIGS. 1 and 2 ) in the expanded configuration can be in the range of 3 mm to 40 mm. In some embodiments, the diameter of the cylindrical saddle region 128 in the expanded configuration can be in the range of 5 mm to 25 mm, 5 mm to 20 mm, 5 mm to 15 mm, or 10 mm to 20 mm (e.g., 5 mm, 10 mm, 15 mm, or 20 mm), inclusive. In various embodiments, the diameter of the cylindrical saddle region 128 in the expanded configuration can be 3 to 5 times larger than the corresponding diameter of the stent in the constrained configuration, while in some embodiments, the diameter of the cylindrical saddle region 128 in the expanded configuration can be 3 to 10 times larger than the corresponding diameter of the stent in the constrained configuration.

[0026] 1 and 2, in the expanded configuration, the first and second retention members 114, 124 may extend radially outward from the outer periphery of the elongated body 110 to define double-walled flanges having respective inner and outer wall surfaces 114a, 114b, 124a, and 124b. For example, the inner wall surface 114a may be the axially inner wall of the first flange, the outer wall surface 114b may be the axially outer wall of the first flange, the inner wall surface 124a may be the axially inner wall of the second flange, and the outer wall surface 124b may be the axially outer wall of the second flange. The radially outermost edge 114c may extend between and connect the inner and outer wall surfaces 114a, 114b. The radially outermost edge 124c may extend between and connect the inner and outer wall surfaces 124a, 124b. The radially outermost edge may be offset from a vertical plane along a longitudinal axis extending between the beginning of the inner wall surface and the end of the outer wall surface of the retaining member, or may be offset from a center point of the distance extending between the cylindrical saddle region and the extreme protrusion or lip. The radially outermost edge may have a diameter greater than the diameter of the cylindrical saddle region. In various embodiments, the radially outermost edge may define the diameter of the respective retaining member.

[0027] In embodiments, the diameter of the first and / or second retention members (such as members 114, 124 in FIGS. 1 and 2 ) can range from 5 mm to 40 mm. Other exemplary retention member diameters can range from 15 mm to 40 mm or from 15 mm to 35 mm. In many embodiments, the retention member diameter can be set to have a specific offset from the diameter of the cylindrical saddle region in the expanded configuration. For example, the stent can be configured to include a difference of 3 mm to 20 mm between the diameter of the cylindrical saddle region and the diameter of the first and / or second retention members in the expanded configuration. In other examples, the first and / or second retention members can be configured to have a diameter that is 1 to 5 times larger than the diameter of the cylindrical saddle region in the expanded configuration. For example, in a device having a cylindrical saddle region with a diameter of 10 mm in the expanded configuration, the first retention member and / or second retention member may have a diameter in the inclusive range of 13 mm to 30 mm, 15 mm to 25 mm, or 16 mm to 20 mm. In another example, a stent having a cylindrical saddle region with a diameter of 20 mm in the expanded configuration may have one or more retention members with a diameter in the inclusive range of 23 mm to 40 mm. It will be understood that some embodiments may include a larger or smaller offset between the diameter of the cylindrical saddle region and the larger diameter of the first retention member and / or second retention member.

[0028] Referring again to FIGS. 1 and 2 , the first retention member 114 may have the same or different axial width as the second retention member 124, where the axial width of the retention member may be measured as the distance along the longitudinal axis between the inner and outer walls of the respective retention members, including their radially outermost edges. In some embodiments, the width of the first retention member 114 and / or the second retention member 124 in the expanded configuration may be in the inclusive range of 0.5 mm to 10.0 mm. Other embodiments may include smaller and / or larger widths of the first retention member and / or the second retention member, such as in the inclusive ranges of 0.5 mm to 6 mm, 2 mm to 6 mm, or 3 mm to 7 mm. In some embodiments, the retention members may have a constant width. In other embodiments, the width of the retention members may vary along a vertical plane.

[0029] 1 and 2, the outer wall 114b of the first retaining member 114 may extend substantially along the longitudinal axis at the axially outermost edge of the first retaining member 114 of the elongate body 110, away from the vertical center plane of the cylindrical saddle region 128, into the protrusion 116 or lip. The outer wall 124b of the second retaining member 124 may extend substantially along the longitudinal axis at the axially outermost edge of the first retaining member 114 of the elongate body 110, away from the vertical center plane of the cylindrical saddle region 128, into the protrusion 126 or lip. In some embodiments, the protrusion 116 and / or the protrusion 126 may have a length in the range of 0 mm to 3 mm (e.g., 0.5 mm to 2.5 mm or 1.0 mm to 1.5 mm, inclusive) in the expanded configuration. The protrusion 116 and / or the protrusion 126 may define a lumen, such as a flange lumen adjacent to the cylindrical saddle region, having a diameter equal to or greater than the diameter of the lumen or saddle lumen defined by the cylindrical saddle region 128. In various embodiments, the lip, or protrusion, may have a flange lumen diameter in the expanded configuration that is at least 0.5 mm to 2.0 mm greater than the diameter of the corresponding cylindrical saddle region 128 in the expanded configuration, e.g., for a saddle diameter in the range of 3 mm to 40 mm, the lip may have a diameter in the range of 3.5 mm to 42 mm. As further exemplary inclusive ranges, for a corresponding cylindrical saddle region diameter of 10 mm in the expanded configuration, the lip may have a diameter in the range of 11 mm to 14 mm. For a corresponding cylindrical saddle region diameter of 15 mm in the expanded configuration, the lip may have a diameter in the range of 16 mm to 19 mm. In another example, a cylindrical saddle region diameter of 20 mm in the expanded configuration may correspond to a lip diameter in the range of 21 mm to 24 mm. Protrusions 116 and / or protrusions 126 may be formed adjacent retention members 114, 124 and saddle lumen 128. Protrusions 116 and / or protrusions 126 may be parallel to the longitudinal axis of the cylindrical saddle region. Alternatively or additionally, protrusions 116 and / or protrusions 126 may be non-parallel to the longitudinal axis. For example, protrusions 116 and / or protrusions 126 may extend radially outward or inward along the longitudinal axis.The radially outward extension of protrusions 116 and / or protrusions 126 may encourage flow through the lumen, for example, by acting as a funnel into the lumen. The radially inward extension of protrusions 116 and / or protrusions 126 may impede flow through the lumen, for example, by defining a smaller entrance thereto.

[0030] Various embodiments can include a total stent length in the expanded configuration ranging from 5 mm to 60 mm. For example, an exemplary deployed stent can have a length of from 10 mm to 50 mm or from 10 mm to 35 mm.

[0031] In various embodiments, the angle of the retention member relative to the circumference and longitudinal axis of the elongate body may be considered to be various angles or may have varying degrees of orientation (compared to a retention member having straight walls) along the axial inner and / or outer walls of the retention member, creating inflection points in the walls of the retention member. For example, as shown in the cross-sectional view of the stent in FIG. 2, outer wall surface 114b and / or outer wall surface 124b may comprise at least a portion of an axially outer wall that extends or bends away from a vertical center plane 202 or centerline of the longitudinal axis of cylindrical saddle region 128. Additionally or alternatively, outer wall surface 114b and / or outer wall surface 124b may comprise at least a portion of an axially outer wall that extends or bends toward vertical center plane 202. Similarly, inner wall surface 114a and / or inner wall surface 124a may comprise at least a portion of an axially inner wall that extends or bends away from a vertical center plane 202 of the longitudinal axis of cylindrical saddle region 128. Additionally or alternatively, inner wall surface 114a and / or inner wall surface 124a may comprise at least a portion of an axially inner wall that extends or bends toward vertical center plane 202. In various embodiments, inner wall surface 114a and outer wall surface 114b of retaining member 114 may be non-parallel to one another and / or inner wall surface 124a and outer wall surface 124b of retaining member 124 may comprise surfaces that are non-parallel to one another.

[0032] The lumen 204 may extend the entire longitudinal length of the cylindrical saddle region 128. The saddle region lumen 204 may include dimensions suitable for various purposes, for example, as described above.

[0033] One or more of the components shown with respect to Figure 2 may have one or more similar aspects to the respective structures shown and / or described with respect to Figure 1. For example, the elongate body of the stent of Figure 2 may be similar or identical to the elongate body 110 described with respect to Figure 1.

[0034] 1 and 2 show a stent with both a first retention member and a second retention member that include a double-walled flange structure, it will be understood that a stent may include only one of the first or second retention members. Additionally or alternatively, a stent may include a first retention member and / or a second retention member that includes an alternative configuration, such as a flared shape, a funnel, an occlusion component, a widening structure, or another configuration for promoting flow through the stent.

[0035] The protrusion 116 in the expanded configuration can define a first protrusion lumen 206, which can have a diameter at least as large as the diameter of the lumen 204. The protrusion 126 in the expanded configuration can define a second protrusion lumen 208, which can have a diameter at least as large as the diameter of the lumen 204. The diameter of the first protrusion lumen 206 can be the same as or different from the diameter of the second protrusion lumen 208. For example, the exemplary diameter of the first protrusion lumen 206 can be defined by the exemplary diameter of the first protrusion 116 as described with respect to FIG. 1, the exemplary diameter of the second protrusion lumen 208 can be defined by the exemplary diameter of the second protrusion 126 as described with respect to FIG. 1, or both. The various dimensions described above in connection with the stent of Figure 1, such as the length and diameter in the restrained configuration, the overall stent length in the expanded configuration, the length and diameter of the saddle region, the width and diameter of the retention member, and the length of the protrusions, may be applicable to the stent of Figure 2, or any stent having a retention member configuration as described below with respect to Figures 3A through 3F.

[0036] Figures 3A through 3F show alternative configurations of the cross-sectional profile of the double-walled flange structure as second retention member 124 in the expanded configuration. In each of Figures 3A through 3F, a cylindrical saddle region 128 is shown extending from the left side of the figure to retention member 124. Retention member 124 is shown extending to protrusion 126 on the right side of the figure.

[0037] The configuration of the flange structure as described with respect to Figures 3A through 3F may be applied to any of the embodiments described herein. For example, the first retaining member 114 as described with respect to Figure 1, the second retaining member 124 as described with respect to Figure 1, or both may have a configuration as described with respect to Figures 3A through 3F. Thus, an embodiment may include multiple retaining members having the same or different configurations. For example, the first retaining member 114 may have the configuration as shown in Figure 3A, and the second retaining member 124 may have the configuration as shown in Figure 3C. Any combination of the described configurations is within the scope of the present disclosure.

[0038] Alternatively, or in addition, various embodiments may include one of the first retaining member 114 or the second retaining member 124 and an alternative configuration at the opposing end. For example, various embodiments may include alternative configurations such as a flange having a perpendicular wall to the respective cylindrical saddle region 128, a flared retaining member, a bulbous retaining member, an angled retaining member, a curled retaining member, a folded retaining member, or another configuration (not shown). Some embodiments may include one or more components for managing the flow of material therethrough. For example, various embodiments may include a valve, a barrier member, a funnel, a tube, or other structure useful for managing flow therethrough.

[0039] In various embodiments of the medical device, at least a portion of the inner wall surface of the retention member, the outer wall surface of the retention member, or both, comprises at least one curved surface, continuous surface, corner, inner radial circumference, outer radial circumference, cylindrical saddle region or center of the medical device. center Surfaces that extend or bend toward the vertical center plane of the region, saddle or center of the medical device center The saddle region may have surfaces that extend or bend away from the vertical center plane of the region, surfaces that are perpendicular to the longitudinal axis of the cylindrical saddle region, surfaces that are parallel to the longitudinal axis of the cylindrical saddle region, or any combination thereof.

[0040] The inner and outer wall surfaces of the retention members can have non-parallel surfaces, as shown by example in Figures 3A-3F. In various embodiments, the retention members can have asymmetric inner and outer wall surfaces. For example, the cross-sectional profile of the first retention member 114 or the second retention member 124, or both, can be asymmetric along the longitudinal axis of the cylindrical saddle region 128. In some embodiments, the asymmetric wall surfaces can each have a shape and / or strength, such as appropriate shape and / or mechanical properties / retention strength, that can each accommodate interaction with tissue.

[0041] The portion of the retention member having the largest outer diameter may comprise a radially outermost edge that may connect, join, and / or extend between the inner and outer wall surfaces of the retention member. For example, the radially outermost edge (e.g., 124c in FIGS. 1-3F) may comprise a ridge along the curved junction of the inner and outer wall surfaces 124a, 124b, as in FIG. 3B, or the radially outermost edge may comprise one or more portions parallel to the longitudinal axis of the cylindrical saddle region 128, as in FIGS. 3A, 3C, 3D, and 3E. The radially outermost edge 124c may or may not be centered on a length along the longitudinal axis between the beginning of the inner wall surface and the end of the outer wall surface of the retention member.

[0042] In various embodiments, at least a portion of the retaining member may comprise a concave surface, such as outer wall surface 124b shown in FIG. 3A. In some embodiments, the concave surface or recess of the retaining member may bend away from the vertical center plane of the cylindrical saddle region along the longitudinal axis (e.g., vertical center plane 202 in FIG. 2). In various embodiments, at least a portion of the retaining member may comprise a convex surface, such as inner wall surface 124a shown in FIG. 3A. In some embodiments, the convex surface or protrusion of the retaining member may bend toward the vertical center plane of the cylindrical saddle region (e.g., vertical center plane 202 in FIG. 2) along the longitudinal axis. The inner and / or outer wall surfaces of each of the first and second retaining members, in any combination thereof, may increase the resistance of the respective retaining members to deformation, thereby increasing the pull-out strength of the retaining members relative to flanges that only have surfaces perpendicular to the longitudinal axis of the cylindrical saddle region. Additionally or alternatively, the inner wall surfaces may engage and maintain apposition of the tissue walls with less trauma to the tissue walls and greater resistance to movement than the respective surfaces perpendicular to the cylindrical saddle region. Thus, stents having retention members according to embodiments of the present disclosure may move less than the respective surfaces perpendicular to the cylindrical saddle region.

[0043] For example, as shown in FIG. 3A, the elongate body can extend from a cylindrical saddle region 128 to the retaining member. While FIG. 3A depicts the second retaining member 124 as having a double-walled flange configuration, it will be appreciated that the first retaining member 114 can have the configuration shown in FIG. 3A. For example, the first retaining member 114 can have a corresponding double-walled flange configuration. Additionally, or alternatively, either the first retaining member 114 or the second retaining member 124 can have an alternative configuration.

[0044] 3A , the cylindrical saddle region 128 may extend to the inner wall surface 124a, which in this example comprises three portions: portion 302a, portion 302b, and portion 302c. The cylindrical saddle region 128 may extend to the concave surface of portion 302a, which may extend to portion 302b. Portion 302b comprises a straight edge that extends at an angle of less than 90 degrees toward the vertical center plane of the cylindrical saddle region (not shown). In some embodiments, the inner wall surface may extend a distance of at least 0.0 mm and no more than 5.0 mm toward the vertical center plane along the longitudinal axis of the cylindrical saddle region. For example, portion 302b may extend 0.5 mm to 1.5 mm toward the vertical center plane of the cylindrical saddle region 128. However, in other embodiments consistent with the present disclosure, the inner wall surface may extend a greater distance toward the vertical center plane along the longitudinal axis of the cylindrical saddle region. Portion 302c comprises a convex curved surface extending between portion 302b and radially outermost edge 124c. Radially outermost edge 124c may comprise a portion parallel to the surface of cylindrical saddle region 128. Radially outermost edge 124c may extend to outer wall surface 124b, which in the example of FIG. 3A may comprise portions 304a and 304b. Portion 304a may comprise a convex surface. In various embodiments, the inner radius of curvature between the inner wall surface and the radially outermost edge may be greater than the inner radius of curvature between the radially outermost edge and the outer wall. For example, as shown in FIG. 3A, portion 302b may have a larger inner circumferential radius than portion 304a. However, it will be appreciated that alternative embodiments may include varying relative radii of circumference between the portions. Portion 304a may extend to portion 304b, which may comprise a concave surface. Portion 304b may extend to protrusion 126, as described elsewhere herein. One or more convex and / or concave surfaces may include the same or different degrees of completed curvature, circumferential radii, lengths, other characteristics, or any combination thereof.

[0045] For the exemplary embodiment shown in FIG. 3B, the retention member may include portions 302a, 302b, and 302c similar to those described with respect to FIG. 3A. However, portion 304a, as shown in FIG. 3B, may include a larger radius of curvature than that shown in FIG. 3A. In FIG. 3B, portion 304a may include a radius of curvature that varies along its length. In some embodiments, portion 304a or other portions may include a non-uniform and / or otherwise undulating curved surface. Portion 304b, as shown in FIG. 3B, may include a recess.

[0046] FIG. 3C illustrates another exemplary embodiment in which the retention member may include portions 302a, 302b, and 302c similar to those described with respect to FIG. 3A and / or FIG. 3B. However, portion 304a as shown in FIG. 3C may include a larger radius of curvature than that shown in FIG. 3A. In FIG. 3C, portion 304b may include a straight edge extending from radially outermost edge 124c and portion 304a back toward cylindrical saddle region 128. Portion 304b may extend to portion 304c, which is shown in FIG. 3C as including a recess. Portion 304c may extend to protrusion 126. In many embodiments, the angle defined by portion 304b and protrusion 126, or the angle of portion 304c, directed toward the exterior of second retention member 124, may be less than 90 degrees.

[0047] An additional exemplary embodiment is shown in FIG. 3D . In FIG. 3D , portion 302a may comprise a concavely curved surface that extends to the linear edge of portion 302b. Portion 302b may extend to the convexly curved surface of portion 302c, which may then extend to radially outermost edge 124c. Radially outermost edge 124c may extend to portion 304a, which may comprise a convexly curved surface. Portion 304a may extend to the linear edge of portion 304b, which may then extend to portion 304c, which may comprise a concave section. Portion 304c may extend to protrusion 126. However, one or more of portions 302a, 302c, 304a, and / or 304c may comprise a smaller radius of curvature, as shown for concavely curved portion 304c in FIG. 3D , for example, compared to concavely curved portion 304c in FIG. 3C . In some embodiments, the concave or convex curved surface of at least one portion may have a radius of curvature small enough to provide a crease or other fold.

[0048] Figure 3E illustrates another exemplary embodiment in which portions 302a, 302b, 302c, 304a, and / or 304b may have one or more similarities to the corresponding portions described with respect to at least one of Figures 3A-3D. However, in Figure 3E, the curved portions of portions 304a and 304b have a smaller radius of curvature than shown for the curved portions of portions 304a and 304b in Figure 3A.

[0049] FIG. 3F illustrates another exemplary embodiment in which the retention member may include similar portions 302a, 302b, and 302c as described with respect to at least one of FIGS. 3A through 3E. Portion 302a, as shown in FIG. 3F, may have a larger radius of curvature than that shown in FIG. 3A. For example, portions such as portion 302a shown in FIG. 3F may have a radius of curvature between 1 mm and 3 mm. In some embodiments, portions 302a and / or 302c may have a radius of curvature between 1.5 mm and 2.1 mm. In FIG. 3F, portion 302a may have a radius of curvature that varies along its length. As shown in FIG. 3F, portion 302a may extend or sink to a radius smaller than each cylindrical saddle region 128. Portion 302d may extend between cylindrical saddle region 128 and portion 302a, or portion 302d may be considered an extension of the cylindrical saddle region that leads to the beginning of portion 302a and the beginning of inner wall surface 124a. In some embodiments, portion 302a or other portions may have uneven and / or otherwise undulating curves. Portion 304b may have a straight portion perpendicular to the longitudinal axis of cylindrical saddle region 128, as shown in FIG. 3F. Portion 304c may have a concave surface that extends to protrusion 126. A portion may have a radius of curvature that is sufficiently small to form a right angle or a relatively right angle. For example, a portion such as portion 304c shown in FIG. 3F may have a radius of curvature between 0.0 mm and 0.5 mm, e.g., between 0.1 mm and 0.3 mm.

[0050] While various portions are described with reference to Figures 3A through 3F, it will be understood that various embodiments may have one or more similarities and / or differences from the illustrated examples. For example, inner wall surface 114a, outer wall surface 114b, inner wall surface 124a, and / or outer wall surface 124b may include more or fewer portions, any of which may include at least one recess, protrusion, straight edge, or any combination thereof. The portions may extend toward the first or second end of the device perpendicular to the surface of the cylindrical saddle region, parallel to the surface of the cylindrical saddle region, at another angle relative to the surface of the cylindrical saddle region, or any combination thereof. Furthermore, the dimensions and / or orientations of any of the portions described with reference to Figures 3A through 3F may be applied alternatively or in combination to other portions described therewith or with different portions and / or retention member profiles within the scope of this disclosure.

[0051] In some embodiments, a smaller radius of curvature in a portion may provide a corresponding higher retention member retention strength. For example, the configuration shown in FIG. 3E may provide greater resistance to deformation of second retention member 124 than the respective configuration in FIG. 3A. Thus, embodiments may be configured according to various retention member strength requirements as dictated by at least one particular procedure, anatomy, or other considerations.

[0052] FIG. 4 shows, by way of example, an embodiment of a delivery method for a medical device as described herein.

[0053] The medical device can be disposed in a constrained configuration between the inner member 402 and outer sheath 404 of the tissue-piercing element. For example, in the constrained configuration, one or more of the first retention member 114, the second retention member 124, or the cylindrical saddle region 128 can be restricted to a smaller outer diameter as described with respect to FIGS. 1-3 compared to their characteristics in the expanded or unconstrained configuration. A sharp tip 416 of the tissue-piercing element can be included to advance from the first body lumen 412 through the tissue layer 410. The sharp tip 416 of the tissue-piercing element can be advanced through the tissue layer 406 into the second body lumen 408. Additionally or alternatively, the tissue-piercing element can include a conductive tip for advancing through the tissue layer 410 and / or the tissue layer 406. In various embodiments, an interstitial space 414 can exist between the tissue layer 410 and the tissue layer 406 prior to deployment of the medical device (e.g., a stent).

[0054] With the end of the tissue-piercing element advanced through the tissue layer 406, the outer sheath 404 may be retracted proximally relative to the inner member 402, or the inner member 402 may be extended distally relative to the outer sheath 404, thereby moving the distal end of the medical device from a constrained configuration to an unconstrained configuration. In particular, the distal end of the medical device may expand into the second retention member 124.

[0055] The medical device can be positioned so that a portion of the inner wall surface 124a of the second retention member 124 contacts the tissue layer 406. The tissue-piercing element can be retracted proximally through the tissue layer 406 such that the second retention member 124 remains within the second body lumen 408. The tissue-piercing element can be retracted proximally through the tissue layer 410 (not shown).

[0056] After deploying the second retention member, the medical device, along with the entire inner member and outer sheath assembly, can be retracted proximally a distance (e.g., a predetermined distance that may be indicated by visual (e.g., colored bands) and / or imaging marker(s) (e.g., radiopaque bands) on the device) so that the first retention member remains constrained between the two and is not prematurely deployed (e.g., in the interstitial space 414). The act of retracting the entire assembly proximally can also act to draw the tissue layers 410, 406 into apposition or further apposition with one another once the second (or distal, in this example) retention member 124 is deployed. When the device has been retracted a sufficient distance to clarify the tissue layer 410, the outer sheath 404 may be retracted proximally relative to the inner member 402, or the inner member 402 may be extended distally relative to the outer sheath 404, thereby moving the proximal end of the medical device from the constrained configuration to the unconstrained configuration. In particular, the proximal end of the medical device may extend to the first retention member 114 .

[0057] FIG. 5 shows a cross-sectional view of a stent after delivery according to the present disclosure. For example, the stent in FIG. 5 can be a stent as described with respect to FIGS. 1-4. Various components of the stent can be similar to those described above. The stent can be positioned within a patient such that the inner wall surface 114a of the first retention member 114 contacts the tissue wall 506 and the outer wall surface 124a of the second retention member 124 contacts the tissue wall 508, with the cylindrical saddle region 128 extending therebetween. The apposing tissue layers can be walls of the same or different tissues. For example, as described with respect to FIG. 4, the tissue wall 506 can correspond to the tissue layer 410, and the tissue wall 508 can correspond to the tissue layer 406. In some embodiments, the first retention member 114 and the second retention member 124 can contact the tissue wall 506 of the first tissue and the tissue wall 508 of the second tissue, such that the first tissue and the second tissue interact at a tissue interface. In some embodiments, first retention member 114 and second retention member 124 can interact with tissue wall 506 and tissue wall 508, causing the respective tissue walls to interact at their contact surfaces to close and / or shorten the width of the space therebetween. For example, the width of interstitial space 414, as described with respect to FIG. 4, can be reduced and / or eliminated. In some embodiments, at least one additional tissue (not shown) can be disposed between the tissue of first tissue wall 506 and the tissue of second tissue wall 508. Thus, the lumen extending through first retention member 114, second retention member 124, and cylindrical saddle region 128 can provide an open internal passageway between first body lumen 502 and second body lumen 504. The stent can be partially or fully coated, for example, to prevent fluids draining from the second body lumen into the first body lumen from leaking through the retention members and / or saddle region of the stent into the interstitial space between the tissue walls.

[0058] As described by way of example with respect to FIG. 5 , the stent can be positioned in a constrained configuration between the inner member and outer sheath of the tissue-penetrating element. For example, in the constrained configuration, one or more of the first retention member 114, the second retention member 124, or the cylindrical saddle region 128 can be constrained to a smaller outer diameter. The sharp end of the tissue-penetrating element can be advanced through the tissue wall and into the second body lumen 504. Additionally or alternatively, the tissue-penetrating element can include a conductive tip for advancing through the tissue wall. Next, the second retention member 124 is positioned within the second body lumen 504, and the distal end 516 of the stent can be advanced distally beyond the lumen of the tissue-penetrating element such that the inner wall surface 124 a is positioned against the tissue wall 508. Next, the tissue-penetrating element can be retracted proximally with the proximal end of the constrained stent such that the proximal portion of the stent is positioned proximal to the tissue wall 506. Next, the proximal portion 518 of the stent can be positioned in the first body lumen 502 so that the first retention member 114 is unconstrained from the sheath and expanded into the first body lumen 502 with the inner wall surface 114a in contact with the tissue wall 506.

[0059] Alternatively, in the above-described method, another instrument having a sharp tip may be advanced along the above-described passageway into the second body lumen 504, 408 to form the passageway, a guidewire may be placed, the other instrument may be withdrawn over the guidewire, a stent according to the various embodiments described above may be loaded onto a delivery catheter that is inserted over the guidewire, and the stent may then be deployed according to the steps outlined above.

[0060] All of the devices and / or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the devices and methods of the present invention have been described in terms of preferred embodiments, it will be apparent to those skilled in the art that changes may be applied to the devices and / or methods, and to the steps or sequence of steps of the methods described herein, without departing from the concept, spirit, and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the present disclosure as defined by the appended claims.

Claims

1. A stent comprising a tubular structure having a first end and a second end and capable of transitioning between a constrained configuration and an expanded configuration, wherein in the expanded configuration, the first end of the tubular structure is expanded to form a first double-walled flange, the second end of the tubular structure is expanded to form a second double-walled flange, and a central region is expanded to define a lumen extending along a longitudinal axis between the first end and the second end, at least one of the first double-walled flange and the second double-walled flange comprises an axially inner wall extending radially outward from the elongated body of the tubular structure and an axially outer wall extending radially outward from the elongated body and spaced from the axially inner wall, at least a portion of the axially inner wall bending along the longitudinal axis toward a vertical center plane of the central region as the axially inner wall extends radially outward; a cross-sectional profile of at least one of the first double-walled flange and the second double-walled flange taken along a plane parallel to the longitudinal axis is asymmetric along the longitudinal direction; Stent.

2. A stent as described in claim 1, wherein the axially inner wall and the axially outer wall of at least one of the first double-wall flange and the second double-wall flange have non-parallel surfaces.

3. The axially inner wall a first curved surface portion that curves along the longitudinal axis toward the vertical center plane of the central region; a second curved portion that curves along the longitudinal axis away from the vertical center plane of the central region; The stent of claim 1 , comprising:

4. The stent of claim 1 , wherein the axially inner wall, the axially outer wall, or both, comprise straight edges.

5. a cylindrical body having a constrained configuration and an expanded configuration, the cylindrical body in the expanded configuration comprises a first retention member, a second retention member, and a saddle region defining a lumen extending along a longitudinal axis between the first retention member and the second retention member; at least one of the first retention member and the second retention member comprises a double-walled flange including an axially inner wall extending radially outward from an elongated body of the cylindrical body and an axially outer wall extending radially outward from the elongated body, at least a radially outer portion of the axially inner wall bending toward a vertical center plane of the saddle region along the longitudinal axis as the axially inner wall extends radially outward; A stent comprising the cylindrical body, wherein the axially inner and outer walls of at least one of the first and second retention members comprise non-parallel surfaces.

6. The axially inner wall a first curved surface portion that curves along the longitudinal axis toward the vertical center plane of the saddle region; a second curved portion that curves along the longitudinal axis away from the vertical center plane of the saddle region; and The stent of claim 5 comprising:

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