Stent

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 the body lumens. [Background technology]

[0002] The placement of a self-expanding stent (e.g., a self-expanding metal 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 material from one body lumen to another.

[0003] However, available stents may have various drawbacks: for example, they may be susceptible to dislodging or migrating 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 through the devices and / or methods of the present disclosure. Summary of the Invention

[0005] In one aspect, a stent may comprise 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 or the second retention member, or both, may comprise 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 the described and other aspects of the disclosure, the inner and outer walls of the first or second retention member, or both, may comprise 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 comprise a recess that bends away from the vertical center plane of the cylindrical saddle region along the longitudinal axis. The inner or outer walls, or both, may comprise straight edges. The inner wall may comprise a convex portion that bends away from the vertical center plane of the cylindrical saddle region along the longitudinal axis. The outer wall may comprise a convex portion that bends toward the vertical center plane of the cylindrical saddle region along the longitudinal axis. An axially outermost edge of the first retention member, or an axially outermost edge of the second retention member, 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 a lumen of the cylindrical saddle region. The lip may comprise an inner diameter of the flange lumen that is equal to or greater than an inner diameter of the cylindrical saddle region lumen. The radially outermost edge may comprise a diameter greater than a 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 a beginning of the inner wall and an 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 a length of the elongate body.

[0007] In one aspect, a stent may comprise a tubular structure having a restrained configuration and an expanded configuration. The tubular structure in the expanded configuration may 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. The central region may define a lumen extending along the longitudinal axis. The first double-walled flange or the second double-walled flange, or both, may comprise an axially inner wall and an axially outer wall. At least a portion of the inner wall may be curved along the longitudinal axis toward a vertical center plane of the central region. A 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 the described and other aspects of the disclosure, the inner and outer walls of the first or second retention member, or both, may comprise non-parallel surfaces. The inner wall may comprise a first curved portion that bends along the longitudinal axis toward the vertical center plane of the central region, the inner wall may comprise a second curved portion that bends along the longitudinal axis away from the vertical center plane of the central region, or the inner wall may comprise both the first and second curved portions. The inner or outer walls, or both, may comprise 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 or 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 or the second retention member, or both, may comprise non-parallel surfaces.

[0010] In the described and other aspects of the disclosure, the inner wall may comprise a first curved portion that bends along the longitudinal axis toward the vertical center plane of the saddle region, the inner wall may comprise a second curved portion that bends along the longitudinal axis away from the vertical center plane of the saddle region, or the inner wall may comprise both the first and second curved portions. In the above and other aspects of the 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 an aspect of the disclosure may have a double-walled flange 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 description 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 to enable a person skilled in the art to understand the present disclosure.

[0012] [Figure 1] 1 illustrates a side view of a medical device according to one or more embodiments described herein. [Diagram 2] 1 illustrates a cross-sectional view of a medical device according to one or more embodiments described herein. [Figure 3A] 13 illustrates an alternative retention member configuration according to various embodiments described herein. [Figure 3B] 13 illustrates an alternative retention member configuration according to various embodiments described herein. [Figure 3C] 13 illustrates an alternative retention member configuration according to various embodiments described herein. [Figure 3D] 13 illustrates an alternative retention member configuration according to various embodiments described herein. [Figure 3E] 13 illustrates an alternative retention member configuration according to various embodiments described herein. [Figure 3F] 13 illustrates an alternative retention member configuration according to various embodiments described herein. [Figure 4] 1 illustrates an aspect of delivery of a medical device according to one or more embodiments described herein. [Diagram 5] 1 illustrates a medical device being positioned within tissue, according to one or more embodiments described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure is not limited to the specific embodiments described. The technical terms used herein are only intended to describe specific embodiments, and are not intended to limit 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 conversion, enteroenterostomy, 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, a balloon catheter. Additionally, such medical devices may facilitate access to an organ, blood vessel or body lumen 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 flow path.

[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 furthest 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 a medical device (e.g., a self-expanding metal stent and / or a duodenal exclusion device, etc.) configured to extend between a first and a second body lumen and 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 the opposing ends of the stent, such as flanges, may be double-walled and may include one or more non-vertical surfaces of 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 the 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, a retention member such as a double-walled flange having one or more non-vertical surfaces may be configured to provide more control over the resistance of the device to being pulled out of the planned position once in place, e.g., resulting in a higher pull-out force when compared to a corresponding retention member having vertical surfaces. For example, a double-walled flange having a non-vertical surface may provide a pull-out 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 a tissue wall within at least one of the first and second body lumens (e.g., comprising an interior having a smaller surface area of ​​tissue contact points) as 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 axially inner and outer walls of a double-walled flange may comprise one or more curved, straight, angular portions, or any combination thereof, each portion may have the same or different length, angle, inner radius of curvature, directionality, inner angle, or other feature relative to another portion. The surfaces of the first retention member and the second retention member 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 placed 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 bending points, which may be points of curvature where a change in the direction of bending occurs.

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

[0020] Various embodiments of the medical devices described herein may include a full 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 a 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 combinations 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 retention member and the second retention member, or a combination thereof, may comprise a solid covering, a porous covering, or other configuration of covering. In some embodiments, such as where the stent has a cylindrical saddle region and a double-walled flange 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 partial length of the stent. For example, a partial coating may cover the entire length of the saddle region but not the flange. 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] With reference to FIG. 1, in one embodiment, a stent of the present disclosure may include an elongate body or tubular structure 110 that defines a lumen and comprises a first portion, a second portion, a length, and a diameter. The elongate body 110 may be covered, uncovered, or a combination thereof. The elongate body 110 may 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 may 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 may comprise a diameter in the range of 2 mm to 6 mm, or 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 in the range of 40 mm to 150 mm. For example, the stent in the constrained configuration may have a length in the range of 40 mm to 100 mm. In some embodiments, the stent in the constrained configuration may have a length in the range of 40 mm to 80 mm.

[0024] The central region may extend between the retention members along the longitudinal axis of the stent. For example, as shown in FIG. 1, the central region may 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 may 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 may comprise a length and a diameter. In embodiments where the stent has double-walled flanges, such that the first and second retention members have axially inner and axially outer walls, with a portion of the inner wall bending toward the vertical center plane of the stent, the length of the cylindrical saddle region may 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, the cylindrical saddle region, which encompasses conditions (i) through (iii) above, may have a length in the range of 5 mm to 150 mm in the expanded configuration, although in some instances, the cylindrical saddle region (such as region 128 in FIGS. 1 and 2) may 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 may be greater 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 may range from 3 mm to 40 mm. In some embodiments, the diameter of the cylindrical saddle region 128 in the expanded configuration may be in the inclusive 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). In various embodiments, the diameter of the cylindrical saddle region 128 in the expanded configuration may be 3 to 5 times greater 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 may be 3 to 10 times greater than the corresponding diameter of the stent in the constrained configuration.

[0026] 1 and 2, the first and second retention members 114, 124 may extend radially outward from the outer circumference of the elongated body 110 in the expanded configuration 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 wall surface 114a and the outer wall surface 114b. The radially outermost edge 124c may extend between and connect the inner wall surface 124a and the outer wall surface 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 midpoint of a distance extending between the cylindrical saddle region and the endmost projection 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 a 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 be in the range of 5 mm to 40 mm. Other exemplary retention member diameters can be in the range of 15 mm to 40 mm or 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 between the diameter of the cylindrical saddle region and the diameter of the first and / or second retention members in the expanded configuration of 3 mm to 20 mm. In other examples, the first and / or second retention members can be configured to have a diameter 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 appreciated 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] 1 and 2, the first retention member 114 may have the same or different axial width as the second retention member 124, and 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 the radially outermost edge. 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 range 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 elongated body 110 into the protrusion 116 or lip away from the vertical center plane of the cylindrical saddle region 128. 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 elongated body 110 into the protrusion 126 or lip away from the vertical center plane of the cylindrical saddle region 128. In some embodiments, the protrusion 116 and / or the protrusion 126 may have a length in the expanded configuration in the range of 0 mm to 3 mm (e.g., inclusive ranges of 0.5 mm to 2.5 mm or 1.0 mm to 1.5 mm). The protrusion 116 and / or the protrusion 126 may define a lumen, such as a flange lumen adjacent 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 comprise a flange lumen diameter at least 0.5 mm to 2.0 mm greater than the diameter of the corresponding cylindrical saddle region 128 in the expanded configuration, such that in the expanded configuration, the lip has a diameter in the range of 3.5 mm to 42 mm, for example, for a saddle diameter in the range of 3 mm to 40 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. The protrusions 116 and / or protrusions 126 may be formed adjacent the retention members 114, 124 and the saddle lumen 128. The protrusions 116 and / or protrusions 126 may be parallel to the longitudinal axis of the cylindrical saddle region. Alternatively or in addition, the protrusions 116 and / or protrusions 126 may be non-parallel to the longitudinal axis. For example, the 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 may include a total stent length in the expanded configuration ranging from 5 mm to 60 mm. For example, an exemplary deployed stent may 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 retaining member relative to the circumference and longitudinal axis of the elongate body may be considered as various angles or may have varying degrees of orientation (compared to a retaining member having vertical walls) along the axial inner and / or outer walls of the retaining member, creating inflection points in the walls of the retaining member. For example, as shown in the cross-sectional view of the stent in FIG. 2, the outer wall surface 114b and / or the outer wall surface 124b may comprise at least a portion of an axial outer wall that extends or bends away from a vertical center plane 202 or center line of the longitudinal axis of the cylindrical saddle region 128. Additionally or alternatively, the outer wall surface 114b and / or the outer wall surface 124b may comprise at least a portion of an axial outer wall that extends or bends toward the vertical center plane 202. Similarly, the inner wall surface 114a and / or the inner wall surface 124a may comprise at least a portion of an axial inner wall that extends or bends away from the vertical center plane 202 of the longitudinal axis of the 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 retention member 114 may be non-parallel with respect to one another and / or inner wall surface 124a and outer wall surface 124b of retention member 124 may comprise non-parallel surfaces with respect to one another.

[0032] The lumen 204 may extend throughout the longitudinal length of the cylindrical saddle region 128. The saddle region lumen 204 may include dimensions suitable for a variety of 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 the stent may include only one of the first or second retention members. Additionally or alternatively, the 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 a 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 a 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, an exemplary diameter of the first protrusion lumen 206 can be defined by an exemplary diameter of the first protrusion 116 as described with respect to FIG. 1, an exemplary diameter of the second protrusion lumen 208 can be defined by an 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 FIG. 1, e.g., length and diameter in the restrained configuration, overall stent length in the expanded configuration, length and diameter of the saddle region, width and diameter of the retention member, and length of the protrusions, may be applicable to the stent of FIG. 2 or any stent having a retention member configuration as described below in connection with FIGS. 3A-3F.

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

[0037] The configuration of the flange structure as described with respect to Figures 3A to 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 to 3F. Thus, an embodiment may include multiple retaining members having the same or different configurations. For example, the first retaining member 114 may have a configuration as shown in Figure 3A, and the second retaining member 124 may have a 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 retaining member, the outer wall surface of the retaining member, or both, may comprise at least one curved surface, a continuous surface, a corner, an inner radial circumference, an outer radial circumference, a surface that extends or bends toward a vertical central plane of the cylindrical saddle region or central region of the medical device, a surface that extends or bends away from the vertical central plane of the saddle or central region of the medical device, a surface perpendicular to the longitudinal axis of the cylindrical saddle region, a surface 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 may comprise non-parallel surfaces as shown by way of example in Figures 3A-3F. In various embodiments, the retention members may comprise 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, may be asymmetric along the longitudinal axis of the cylindrical saddle region 128. In some embodiments, the asymmetric walls may each have a shape and / or strength, such as retention strength, that may be adapted to interact with tissue of appropriate shape and / or mechanical properties / interactions, respectively.

[0041] The portion of the retention member having the greatest 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 the 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., the 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 the inner wall surface 124a as 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 along the longitudinal axis (e.g., the vertical center plane 202 in FIG. 2). With a configuration that includes a portion that is non-perpendicular to the cylindrical saddle region, the inner wall surface and / or the outer wall surface of each of the first and second retaining members, in any combination thereof, may increase the resistance of the respective retaining member to deformation, thereby increasing the pull-out strength of the retaining member relative to a flange that includes only surfaces that are 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, and thus a stent having retention members according to embodiments of the present disclosure may move less as compared to the respective surfaces perpendicular to the cylindrical saddle region.

[0043] For example, as shown in Figure 3A, the elongate body may extend from a cylindrical saddle region 128 to the retaining member. Although Figure 3A illustrates the second retaining member 124 as a double-walled flange configuration, it will be appreciated that the first retaining member 114 may include the configuration shown in Figure 3A. For example, the first retaining member 114 may include a corresponding double-walled flange configuration. Additionally or alternatively, either the first retaining member 114 or the second retaining member 124 may include alternative configurations.

[0044] With reference to FIG. 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 0.0 mm to 5.0 mm along the longitudinal axis of the cylindrical saddle region toward the vertical center plane. 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 along the longitudinal axis of the cylindrical saddle region toward the vertical center plane. 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 completed angles of curvature, circumferential radii, lengths, other characteristics, or any combination thereof.

[0045] With respect to 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 may include a recess, as shown in FIG. 3B.

[0046] FIG. 3C illustrates another exemplary embodiment in which the retaining member may comprise portions 302a, 302b, and 302c similar to those described with respect to FIG. 3A and / or FIG. 3B. However, portion 304a as illustrated in FIG. 3C may comprise a larger radius of curvature than that illustrated in FIG. 3A. In FIG. 3C, portion 304b may comprise 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 illustrated in FIG. 3C as comprising 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 retaining 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 concave curved surface that extends to a straight edge of portion 302b. Portion 302b may extend to a convex 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 convex curved surface. Portion 304a may extend to a straight 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 concave portion 304c in FIG. 3D, for example, as compared to concave portion 304c in FIG. 3C. In some embodiments, the concave or convex surface of at least one portion may have a radius of curvature small enough to include a crease or other fold.

[0048] Figure 3E illustrates another example 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, but in Figure 3E, the curved portions of portions 304a and 304b have a smaller radius of curvature than that illustrated for the curved portions of portions 304a and 304b in Figure 3A.

[0049] FIG. 3F illustrates another exemplary embodiment in which the retaining member may comprise similar portions 302a, 302b, and 302c as described with respect to at least one of FIG. 3A-3E. The portion 302a may comprise a larger radius of curvature than that shown in FIG. 3A, as shown in FIG. 3F. For example, a portion such as portion 302a shown in FIG. 3F may comprise a radius of curvature between 1 mm and 3 mm. In some embodiments, portions 302a and / or 302c may comprise a radius of curvature between 1.5 mm and 2.1 mm. In FIG. 3F, portion 302a may comprise 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 cylindrical saddle region leading to the beginning of portion 302a and the beginning of inner wall surface 124a. In some embodiments, portion 302a or other portions may have a non-uniform and / or otherwise undulating curvature. 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 extending to protrusion 126. The portions 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, for example between 0.1 mm and 0.3 mm.

[0050] Although various parts are described with respect to Figures 3A to 3F, it will be understood that various embodiments may have one or more similarities and / or differences from the examples shown. 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 parts, any of which may include at least one recess, protrusion, straight edge, or any combination thereof. The parts 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 to the surface of the cylindrical saddle region, or any combination thereof. Furthermore, any of the dimensions and / or orientations of the parts described with respect to Figures 3A to 3F may be applied in the alternative or in combination to other parts described with them or with different parts and / or retention member profiles within the scope of the present 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 the second retention member 124 than the respective configuration of FIG. 3A. Thus, embodiments may be configured according to various retention member strength requirements as necessitated by at least one particular procedure, tissue, or other considerations.

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

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

[0054] With the end of the tissue-piercing element advancing 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 the constrained configuration to the 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 such that a portion of the inner wall 124a of the second retention member 124 contacts the tissue layer 406. The tissue penetrating 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 penetrating 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 assembly of inner member and outer sheath can be retracted proximally a distance (e.g., a predetermined distance that may be indicated by visual (e.g., a colored band) and / or imageable marker(s) (e.g., a radiopaque band) 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 to 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 clear the tissue layer 410, the outer sheath 404 can be retracted proximally relative to the inner member 402, or the inner member 402 can 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 having completed delivery of the present disclosure. For example, the stent of 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 in 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, the tissue wall 506 can correspond to the tissue layer 410 and the tissue wall 508 can correspond to the tissue layer 406 as described with respect to FIG. 4. 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 the tissue interface. In some embodiments, the first retention member 114 and the second retention member 124 may interact with the tissue wall 506 and the tissue wall 508 to cause interaction of the respective tissue walls at the contacting surfaces to close and / or shorten the width of the space therebetween. For example, the width of the interstitial space 414 as described with respect to FIG. 4 may be reduced and / or eliminated. In some embodiments, at least one additional tissue (not shown) may be disposed between the tissue of the first tissue wall 506 and the tissue of the second tissue wall 508. Thus, the lumen extending through the first retention member 114, the second retention member 124, and the cylindrical saddle region 128 may provide an open internal passageway between the first body lumen 502 and the second body lumen 504. The stent may be partially or completely covered, for example, to prevent fluid 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 may be disposed in a constrained configuration between the inner member and the 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 may be constrained to a smaller outer diameter. The sharp end of the tissue-penetrating element may be advanced through the tissue wall and into the second body lumen 504. Additionally or alternatively, the tissue-penetrating element may include a conductive tip for advancing through the tissue wall. The distal end 516 of the stent may then be advanced distally beyond the lumen of the tissue-penetrating element such that the second retention member 124 is disposed within the second body lumen 504 and the inner wall surface 124a is disposed against the tissue wall 508. The tissue-penetrating element may then be retracted proximally with the proximal end of the constrained stent such that the proximal portion of the stent is disposed proximal to the tissue wall 506. The proximal portion 518 of the stent can then be positioned in the first body lumen 502 such 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 methods described above, a separate instrument having a sharp end may be advanced along the passageway into the second body lumen 504, 408 to form the passageway, a guidewire may be placed, the separate 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 placed 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. Although 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 will be apparent to those skilled in the art and are deemed to be within the spirit, scope and concept of the present disclosure as defined by the appended claims.

Claims

1. an elongate body configured to be expandable between a first constrained configuration and a second unconstrained configuration; the elongate body in the second, unconstrained configuration includes 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, comprises a double-walled flange having an axially inner wall, an axially outer wall and a radially outermost edge extending therebetween; A stent wherein at least a portion of the inner wall curves along the longitudinal axis toward a vertical center plane of the cylindrical saddle region.

2. The stent of claim 1 , wherein the inner and outer walls of the first retention member, or the second retention member, or both, comprise non-parallel surfaces.

3. 3. The stent of claim 1 or 2, wherein at least a portion of the outer wall curves along the longitudinal axis away from the vertical center plane of the cylindrical saddle region.

4. 4. The stent of claim 1, wherein the outer wall comprises a recess that bends along the longitudinal axis away from the vertical center plane of the cylindrical saddle region.

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

6. 6. The stent of claim 1, wherein the inner wall comprises a convex portion that bends away from the vertical center plane of the cylindrical saddle region along the longitudinal axis.

7. 7. The stent of claim 1, wherein the outer wall comprises a convex portion that curves along the longitudinal axis toward the vertical center plane of the cylindrical saddle region.

8. 8. The stent of claim 1, wherein the axially outermost edge of the first retention member or the axially outermost edge of the second retention member, or both, extend away from the vertical center plane of the cylindrical saddle region to a lip that defines a lumen of the double-walled flange, the flange lumen being adjacent to the cylindrical saddle region lumen.

9. 9. The stent of claim 8, wherein the lip comprises an inner diameter of the flange lumen that is equal to or greater than an inner diameter of the cylindrical saddle region lumen.

10. 10. The stent of claim 1, wherein the radially outermost edge has a diameter greater than a diameter of the cylindrical saddle region.

11. 11. The stent of claim 1, wherein the radially outermost edge comprises a cylindrical portion parallel to the longitudinal axis.

12. 12. The stent of claim 1, wherein an inner radius of curvature between the inner wall and the radially outermost edge is greater than an inner radius of curvature between the radially outermost edge and the outer wall.

13. 13. The stent of claim 1, wherein the radially outermost edge is offset from a vertical plane along the longitudinal axis between the beginning of the inner wall and the end of the outer wall.

14. 14. The stent of any one of claims 1 to 13, wherein the elongate body comprises a braid of one or more wires.

15. 15. The stent of any one of claims 1 to 14, further comprising a circumferential covering extending completely or partially along the length of the elongate body.

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