Multi-flaring shoulder anti-migration support

Abstract

The present disclosure relates to systems, devices, and procedures for forming a flow path inside or through a body lumen. In one example, a stent includes an elongate body configured to expand between a first constrained configuration and a second unconstrained configuration. The elongate body in the second unconstrained configuration may include a first end, a second end, and a cylindrical saddle region extending therebetween. The first end may include a first retaining member and a second retaining member, and the second end may include a third retaining member and a fourth retaining member.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 331,997, filed on April 18, 2022, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] The present disclosure relates generally to the field of medical devices. In particular, the present disclosure relates to medical devices for promoting the flow of fluids and materials within or through body cavities, such as stents that maintain open flow channels within, through, or between body cavities. Background Art

[0003] Placing a self-expanding stent (e.g., a self-expanding metal stent or SEMS) inside an anatomical region (e.g., a body lumen, passage, vessel, duct, etc.) can enable fluid communication from one region to another. For example, a stent can enable material to flow from one body lumen to another.

[0004] However, available stents may come with various disadvantages. For example, the stent may be more likely to move or migrate from a desired location, such as in response to forces generated by the patient's movement or the natural peristaltic motion of surrounding tissue.

[0005] Various available stents may be configured to resist migration via atraumatic engagement of tissue (eg, via protrusions configured to latch into the tissue), in some cases causing trauma to the tissue, which may result in pain to the patient and / or risk of infection.

[0006] Therefore, there is a need for devices that can effectively interface with tissue, inhibit migration, and not substantially damage the tissue.A variety of beneficial medical outcomes can be achieved by the devices, systems, and / or methods of the present disclosure. Summary of the invention

[0007] In one aspect, the stent may include an elongated body configured to expand between a first constrained configuration and a second unconstrained configuration. The elongated body in the second unconstrained configuration may include a first end, a second end, and a cylindrical saddle region extending therebetween. The first end may include a first retaining member and a second retaining member. The second end may include a third retaining member and a fourth retaining member.

[0008] In the above aspects and other aspects, the second retaining member may include a first radially outward surface that is substantially cylindrical, or the third retaining member may include a second radially outward surface that is substantially cylindrical, or both. The second retaining member may include a first axially inner face coupled to the first radially outward surface at a first corner, or the third retaining member may include a second axially inner face coupled to the second radially outward surface at a second corner, or both. The first axially inner face may include a curved profile, or the second axially inner face may include a curved profile, or both. The first corner may include an inner angle of 90 degrees or less. The second corner may include an inner angle of 90 degrees or less. The second retaining member may be uncovered along the radially outermost surface. The third retaining member may be uncovered along the radially outermost surface. The first corner may be uncovered. The second corner may be uncovered. The first retaining member may be configured to interface with tissue substantially along its entire first longitudinal length. The fourth retaining member may be configured to interface with tissue substantially along its entire second longitudinal length. The first end may include a first cylindrical portion extending between the first retaining member and the second retaining member, or the second end may include a second cylindrical portion extending between the third retaining member and the fourth retaining member, or both. The first retaining member and the fourth retaining member, the second retaining member and the third retaining member, or the first retaining member, the second retaining member, the third retaining member, and the fourth retaining member may each be configured to interface with the tissue atraumatically around the radially outermost circumference of the corresponding retaining member. The stent may be formed by at least one braided or woven filament, and the at least one braided or woven filament includes different pitch densities, angles, or patterns at one or more of the first retaining member, the second retaining member, the cylindrical saddle region, the third retaining member, or the fourth retaining member, or any combination thereof in the second configuration. The first retaining member may include an asymmetric cross-section in a plane orthogonal to the longitudinal axis of the lumen extending through the elongated body, or the second retaining member may include an asymmetric cross-section in a plane orthogonal to the longitudinal axis, or both. The first retaining member may include an asymmetric cross-section in a longitudinal plane parallel to a longitudinal axis extending through the lumen of the elongated body, or the second retaining member may include an asymmetric cross-section in a longitudinal plane parallel to the longitudinal axis, or both. The elongated body may include at least a partial covering.

[0009] On the other hand, the medical device may include an elongated body that defines an inner cavity extending therethrough. The elongated body may be configured to transition between a first configuration and a second configuration. In the second configuration, the elongated body may include at least four retention features. The at least four retention features may include at least a second retention member and a third retention member, each retention member including a shoulder. At least one or more shoulders of the first retention member and the second retention member may each include an inner angle of 90 degrees or less. One or more shoulders may be configured to interface with the tissue. The at least four retention members may include at least a first retention member and a fourth retention member, and the first and fourth retention members are configured to interface with the tissue without trauma. In the second configuration, the elongated body may include a cylindrical region extending between the second retention member and the third retention member, between the first retention member and the second retention member, between the third retention member and the fourth retention member, or any combination thereof.

[0010] In the above aspects and other aspects, one or more of the first retaining member, the second retaining member, the third retaining member or the fourth retaining member can be configured to interface with the tissue of the radial outermost circumference around the corresponding retaining member without trauma. The first retaining member may include an asymmetric cross-section in a plane orthogonal to the longitudinal axis of the inner cavity extending through the body. The second retaining member may include an asymmetric cross-section in a plane orthogonal to the longitudinal axis. The elongated body can be formed by at least one braided or woven filament. The at least one braided or woven filament may include different pitch densities, angles or patterns at the first retaining member, the second retaining member, the cylindrical saddle region, the third retaining member or the fourth retaining member or any combination thereof in the second configuration. The elongated body may include at least a portion of the covering.

[0011] On the other hand, the system may include a delivery catheter. The delivery catheter may include an inner member. The delivery catheter may include an outer sheath slidably arranged around the inner member. The delivery catheter may include a stent disposed between the inner member and the outer sheath in a first configuration. The stent may be configured to transition between a first configuration and a second configuration when deployed (or deployed) between the inner member and the outer sheath. In the second configuration, the stent may include at least four retaining members, including a second retaining member and a third retaining member, each retaining member of the second retaining member and the third retaining member having at least one shoulder separated by a cylindrical saddle region. The at least four retaining members may include a first retaining member and a fourth retaining member, the first retaining member and the fourth retaining member being respectively disposed on the side of the second retaining member and the third retaining member farthest from the cylindrical saddle region. The first retaining member, the second retaining member, the third retaining member, the fourth retaining member or any combination thereof may be configured to interface with tissue without trauma. The system may include a handle configured to fix and unfasten (e.g., lock and unlock) the inner member and the outer sheath relative to each other. The handle may be configured to independently deploy each of the at least four retaining members of the stent at a corresponding target position.

[0012] In the above aspects and other aspects, the first retaining member and the fourth retaining member can be configured to interface with tissue atraumatically. The first retaining member and the fourth retaining member can be configured to interface with tissue atraumatically around the radially outermost circumference of the corresponding retaining member. The support can be formed by at least one braided or woven filament. The at least one braided or woven filament can include different pitch densities, angles or patterns at the first retaining member, the second retaining member, the cylindrical saddle region, the third retaining member or the fourth retaining member or any combination thereof in the second configuration. The support can include at least a partial covering. The first retaining member, the second retaining member, the third retaining member or the fourth retaining member or any combination thereof can include an asymmetric cross-section in a plane orthogonal to the longitudinal axis of the lumen extending through the support. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Non-limiting examples of the present disclosure are described with reference to the accompanying drawings, which are schematic and are not intended to be drawn to scale. In the drawings, each identical or nearly identical component depicted is generally represented by a single numeral. For purposes of clarity, not every component is labeled in every drawing, nor is every component of each of every embodiment of the present disclosure shown, where illustration is not necessary to allow those skilled in the art to understand the present disclosure. In the drawings:

[0014] Figure 1A An example of a stent deployed in a body lumen is depicted in accordance with an embodiment of the present disclosure.

[0015] Figure 1B Depicted Figure 1A Dimensional details of the bracket.

[0016] Figure 2 An example of a stent with a partial covering according to an embodiment of the present disclosure is depicted.

[0017] Figure 3A One example of a stent having a varying weaving pitch according to an embodiment of the present disclosure is depicted.

[0018] Figure 3B One example of a woven aperture according to an embodiment of the present disclosure is depicted.

[0019] Figure 4A-4B Various dimensional aspects of cross-sections of retaining members in examples according to embodiments of the present disclosure are depicted.

[0020] Figures 5A-5M Depicted are cross-sectional profiles of various examples of retaining members according to embodiments of the present disclosure.

[0021] Figures 6A-6K Depicted are side views of various examples of retaining members according to embodiments of the present disclosure.

[0022] Figure 7A-7B Depicted are examples of mandrels and fixtures that may be used to manufacture stents according to embodiments of the present disclosure.

[0023] Figure 8 A delivery system according to an embodiment of the present disclosure is depicted.

[0024] Figures 9A-9E One example of staged deployment of a stent according to an embodiment of the disclosed method is depicted. DETAILED DESCRIPTION

[0025] The present disclosure is not limited to the specific embodiments described. The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the scope beyond the appended claims. Unless otherwise defined, all technical terms used herein have the same meaning as those generally understood by ordinary technicians in the field to which the present disclosure belongs.

[0026] Although embodiments of the present disclosure are described with specific reference to medical devices (e.g., stents, etc.) and systems for draining fluids through lumens (e.g., esophagus, etc.), it should be understood that such medical devices can be used in various medical procedures (e.g., external biliary drainage conversion, enterostomy, gastroduodenostomy, and gastroileostomy, etc.) to establish and / or maintain temporary or permanent open flow or drainage channels in or between various body organs, lumens, ducts, vessels, fistulas, cysts, and spaces (e.g., esophagus, dermis, stomach, duodenum, jejunum, small intestine, gallbladder, kidney, pancreas, bile duct / pancreatic tree, bladder, ureter, abscess, encapsulated pancreatic necrosis (WOPN), bile duct, etc.). The device can be inserted via different access points and routes (e.g., percutaneous, endoscopic, laparoscopic, or some combination thereof). The medical devices disclosed herein are self-expanding, but in other embodiments, the medical device can be expandable by other means (including, for example, balloon catheters). Furthermore, such medical devices are not limited to drainage, but can facilitate access to an organ, vessel, or body cavity for other purposes, such as creating a pathway to divert or bypass fluids or solids from one location to another, remove obstructions, and / or deliver therapeutics, including non-invasive or minimally invasive manipulation of tissue within an organ and / or introduction of pharmacological agents via an open flow channel.

[0027] As used herein, the singular forms "a", "an", and "the" and the absence of quantifiers are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that when used herein, the terms "include" and / or "comprise" specify the presence of described 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 sets thereof.

[0028] As used herein, the term "distal" refers to the end farthest from the medical professional when the device is introduced into a patient, and the term "proximal" refers to the end closest to the medical professional when the device is introduced into a patient.

[0029] 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 inside a body cavity and help maintain a temporary or permanent open path for fluid to flow therethrough. The medical device may include at least four retaining members configured to abut against tissue and thereby resist migration of the medical device.

[0030] As described herein, one or both of the second and third retaining members along the opposite longitudinal sides (e.g., flanges) of the stent can be double-walled and include one or more substantially vertical or non-vertical surfaces of the axially inward and axially outward walls of the flanges, which are oriented relative to the cylindrical saddle-shaped area extending along the longitudinal axis between the flanges. When compared with, for example, a corresponding retaining member having only vertical surfaces, this configuration of non-vertical surfaces can reduce the migration of the medical device relative to the tissue abutted or engaged by the flange. Additionally or alternatively, a retaining member as a double-walled flange with one or more non-vertical surfaces can be configured to provide more control of the resistance to pulling out of its intended position once the device is deployed, for example, resulting in a higher pull-out force compared to a corresponding retaining member with a vertical surface. In various embodiments, one or more non-vertical surfaces can also be configured to interact with at least one tissue wall of the first body cavity and the second body cavity in a less traumatic manner (e.g., an inner wall having a tissue contact point with a smaller surface area) compared to, for example, a vertical surface or another surface having at least one tissue engaging element (such as a prong, barb, hook, or other similar design).

[0031] As described herein, one or both of the first and fourth retaining members along the relative longitudinal sides of the stent (such as the flared area) can be in addition against tissue, thereby reducing the risk of stent migration. In various embodiments, at least the first and fourth retaining members can be configured to interface with the tissue atraumatically against or engaged. In various embodiments, the first and / or fourth retaining members can be configured to reduce the pressure between the second and / or third retaining members that are respectively against or engaged with tissue. It is not desirable to be bound by any particular theory, so it is believed that the first and fourth retaining members (such as those described herein) can reduce the risk of stent damage to abutting or engaging tissue, while reducing the risk of stent migration. It should be understood that the different engagement degrees of one or more of the first, second, third and / or fourth retaining members can be customized by adjusting the geometry, radial strength, etc. of the corresponding or at least one alternative retaining member.

[0032] Go to the attached picture, Figure 1A Depicted is a stent 102 according to various examples described herein. The stent 102 is positioned within a tissue "T" defining a lumen "L" having a natural lumen diameter "DL". It should be understood that in alternative examples, stents according to the present disclosure can be positioned across multiple tissues and / or lumens, such as in an end-to-end anastomosis, an end-to-side anastomosis, or a side-to-side anastomosis. In various examples, the stent 102 can be positioned across a target tissue and / or treatment area, such as a stenosis "S". The embodiments are not limited in this context.

[0033] In some embodiments, a stent according to the present disclosure can include at least one solid surface, such as a polymer or silicone surface (not shown). In some embodiments, a stent, such as stent 102, can be formed in whole or in part from at least one filament braid, such as a polymer or metal (e.g., nitinol) wire. In various examples, a stent can include a shape memory material. For example, stent 102 is formed from at least one wire 124, which can be pre-formed into an expanded configuration (e.g., such as Figure 1A to Figure B), and is subsequently constrained or otherwise loaded into a delivery system, such as Figure 8 and / or Fig.9A As shown in Figure E and discussed above.

[0034] The stent 102 can include a first end 104, a second end 106, and an intermediate region 108 (e.g., a saddle region, a cylindrical saddle region, etc.) extending therebetween. In various examples, the stent 102 can include at least four retaining members configured to abut against tissue (such as tissue T).

[0035] In various embodiments, one or both of the first end 104 and the second end 106 may include a plurality of retaining members. For example, the first end 104 may include a first retaining member 114 and a second retaining member 110. The second end 106 may include a third retaining member 112 and a fourth retaining member 116.

[0036] Various embodiments may include at least two tissue-abutting shoulders, flanges, etc. as retaining members. For example, the retaining members 110, 112 of the stent 102 may include tissue-abutting shoulders. Figure 1B As shown, the retaining member 110 may include faces 160, 162, each of which is transverse to the axis AA. Face 160 may be an axial inner face, and face 162 may be an axial outer face (i.e., along the axis AA). In some embodiments, the retaining member 110 may continue from faces 160, 162 to enter corners 152, 154 (i.e., forming a shoulder), and corners 152, 154 may be directly (not shown) connected together or connected together by an intervention section of the stent body (such as a cylindrical portion 168). It should be understood that the intervention section of the stent body inside the retaining member of the present disclosure may include one or more straight and / or curved parts. In various embodiments, the intervention section of the stent body (such as a cylindrical portion 168) may form a radially outward surface, which is configured to interface with the tissue (form an interface contact). For example, the retaining member as described herein may be configured to interface with the tissue around the radially outermost circumference. Each embodiment is not limited in this context.

[0037] Similarly, retaining member 112 may include faces 164, 166 extending into corners 156, 158, respectively. Face 164 may be an axially inner face, and face 166 may be an axially outer face (i.e., along axis AA). Corners 156, 158 may be coupled together directly (not shown) or coupled via an intervening section (such as cylindrical portion 170).

[0038] In some embodiments, the plurality of retaining members can be directly adjacent to each other (i.e., without spaces along the stent therebetween). In other embodiments, such as for stent 102, the retaining members can be separated by intervening extents (spacers) of the stent body, which can be cylindrical, sloped, undulating, or other shapes. For example, saddle region 118 extends between first retaining member 114 and second retaining member 110, and saddle region 120 extends between third retaining member 112 and fourth retaining member 116.

[0039] Retention members according to the present disclosure may include various geometries, sizes, angles, radii of curvature, etc. along their own portions to form an interface against or engaging tissue with a desired (and / or lack thereof) conformability to the tissue, radial strength, pull-out force, etc. For example, as described with respect to Figure 5A As described above, the faces of the retaining members can be disposed at different angles relative to the surfaces of the saddle regions, such as the intermediate region 108, the saddle region 118, or the saddle region 120. It will be appreciated that the retaining members of the present disclosure can be correspondingly designed to interface more or less atraumatically with the tissue being abutted or engaged.

[0040] In various embodiments, one or more of the first, second, third, or fourth retaining members may include shapes, sizes, etc. that are different from each other. For example, the second and third retaining members 110, 112 of the stent 102 include shoulders that abut against the tissue, and the first and fourth retaining members 114, 116 include flared regions that can each be configured to engage with the tissue interface along part or all of its longitudinal length (e.g., around its radially outward surface). It should be understood that various shapes, sizes, materials (e.g., polymer filaments and / or metal filaments), material arrangements (e.g., weaving pitches, weaving patterns, the number of filaments, etc.) can present alternative mechanical properties, such as flexibility, radial strength / force, etc. Therefore, any or each of the retaining members 110, 112, 114, 116 can be configured to provide customized mechanical properties to the stent 102. Similarly, each of the intermediate region 108, the saddle region 118, or the saddle region 120 can include one or more similarities or differences with each other.

[0041] According to some embodiments, the stent 102 defines a lumen 122 extending longitudinally therethrough (ie, extending continuously along the axis "AA" through the first end 104, the middle region 108, and the second end 106, such as Figure 1B As shown in FIG. 1 , the stent 102 can thus facilitate fluid flow through the lumen L of the tissue T.

[0042] Figure 1B A side view of the stent 102 is shown having various aspects and dimensions that can be customized independently or collectively. For example, the middle region 108 has a longitudinal length "L1" (i.e., measured along the longitudinal axis AA) and a maximum diameter "D1". The second retaining member 110 includes a longitudinal length "L2" and a maximum diameter "D2", and the third retaining member 112 includes a longitudinal length "L3" and a maximum diameter "D3". The first retaining member 114 includes a longitudinal length "L4" and a maximum diameter "D4", and the fourth retaining member 116 includes a longitudinal length "L5" and a maximum diameter "D5". The saddle region 118 includes a longitudinal length "L6" and a maximum diameter "D6", and the saddle region 120 includes a longitudinal length "L7" and a maximum diameter "D7".

[0043] In various embodiments, L2 and L4 can be substantially the same, L3 and L5 can be substantially the same, or both. In some examples, L3 can be larger than L2, for example, greater than 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100%, although alternative sizes are also contemplated. Similarly, L5 can be independently larger than L4. In other examples, L3 and / or L5 can be smaller than one or both of L2 and / or L4, such as smaller by 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%. The embodiments are not limited in this context.

[0044] In some embodiments, L6 may be at least as large as or larger than one or both of L2 or L4, L7 may be at least as large as or larger than one or both of L3 or L5, or both. In various embodiments, L6 and L7 may be substantially the same. L6 and / or L7 may be at least as large as or substantially the same as L1. In other embodiments, L6 and / or L7 may be 20%, 25%, 30%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, 150% or another percentage of L1. The embodiments are not limited in this context.

[0045] In various examples according to the present disclosure, one or more of the diameters D1, D2, D3, D4, D5, D6, or D7 can be at least as large as DL. Thus, various aspects of the stent 102 can be configured to interface with the tissue T and / or the stenosis S to accommodate the stent 102 within the lumen L. In some embodiments, at least one or more of D2, D3, D4, or D5 can be greater than DL to apply radially outward pressure to the tissue T. In various examples, such as Figure 1A In the example shown, one or more of the retention members 110, 112, 114, or 116 can accordingly expand or securely engage a corresponding engagement portion of the tissue T. It will be appreciated that, by having aspects of the stent 102 that extend beyond the natural resting position of the tissue T (i.e., greater than the maximum diameter of the DL), exerting such radial pressure on the tissue T can further reduce the tendency of the stent 102 to migrate within the lumen L. In some embodiments, for example, a corner or edge of one or more of the retention members 110, 112, 114, or 116 can resist migration based on a friction fit or interference fit with the tissue T.

[0046] It will be appreciated that adjustment of one or more of the diameters D1, D2, D3, D4, D5, D6, or D7 and / or the lengths L1, L2, L3, L4, L5, L6, or L7 can affect the interaction of the stent 102 with the tissue T differently and / or variably along its length. For example, if D4 is significantly greater than D2, the first retaining member 114 can slightly or substantially lift the surface of the tissue T away from the surface of the stent 102, thereby reducing the pressure of part or all of the second retaining member 110 against the tissue T. As a result, one or both of the corners 152, 154 can engage the tissue T less traumatically. The effect of the relatively larger diameter D4 relative to the diameter D2 can be increased by reducing the length L6, because the tissue T can be stretched slightly more over the saddle region 118. However, increasing the length L6 may allow the tissue T to conform more closely to the saddle region 118, centralize or securely engage the expansion of the tissue T at the retaining members 110, 114, thereby increasing the friction between the retaining members 110, 114 and the tissue T and / or the trauma of the retaining members 110, 114 to the tissue T along part or all of their respective lengths. The embodiments are not limited in this context.

[0047] Various stents according to the present disclosure may include full or partial coverings, coatings, etc. For example, Figure 2 As shown, the support 202 may include one or more similarities with the support 102 described above, but also include a partial covering. In particular, the retaining members 210, 212, 214 and 216 may correspond to the retaining members 110, 112, 114 and 116, respectively, and include similar sizes, material properties and / or mechanical properties. For example, faces 260, 262, 264 and 266 correspond to faces 160, 162, 164 and 166, respectively, and corners 252, 254, 256 and 258 correspond to corners 152, 154, 156 and 158, respectively. Similarly, the middle region 208 and the saddle regions 218, 220 may include one or more similarities with the middle region 108 and the saddle regions 118, 120, respectively, and the axis AA may extend longitudinally through the support 202. The support 202 may be formed by a filament braid 224 and define an inner cavity 222 extending therethrough.

[0048] However, stent 202 includes a partial covering 272 that extends along retaining member 114, saddle region 118 and face 254, as well as face 260, intermediate region 208, face 264, face 266, saddle region 120, and retaining member 216. Thus, cylindrical regions 268, 270 and corners 252, 254, 256, and 258 are uncovered, with filament braid 224 exposed to directly interface with abutting or engaging tissue.

[0049] Where present, the covering 272 may extend between or across at least one aperture of the weave pattern of the filament braid 224 to prevent tissue ingrowth and / or fluid leakage therethrough. Figure 2 In addition to or alternatively to the covered areas shown, the covering 272 can extend across the cylindrical regions 268 and / or 270. Without wishing to be bound by any particular theory, it is believed that the uncovered regions of the stent formed by the filament braid can enable tissue ingrowth, which reduces the risk of stent migration. Thus, various examples can include one or more of the uncovered retaining members 214, 216, faces 260, 262, 264, 266, or intermediate regions 208 to increase the pull-out force on the corresponding covered stent and / or reduce the risk of stent migration (e.g., due to the patient's natural movement).

[0050] In some embodiments according to the present disclosure, one or more sections of the stent 202 may be uncovered along the portion of the stent that is against the tissue. For example, one or more of the retaining members 210, 212, 214, 216 may be uncovered along at least the radially outermost surface (e.g., the cylindrical regions 268, 270 of the corresponding retaining members 210, 212) configured to interface with the tissue T. It should be understood that various patterns, ranges, and / or covering materials may be applied to one or more portions of the stent 202 to customize the interaction between the stent 202 and the tissue T, for example, to achieve the desired pull-out force and / or retention strength of the stent. The embodiments are not limited in this context.

[0051] Figure 3A An additional example of a stent 302 formed of at least one filament braid 324 having a varying pitch is shown. Various examples of stents according to the present disclosure can include two or more portions having filament braids of different pitches, different weave patterns, different numbers of filaments woven together and / or filament materials, and the two or more portions can each include different radial strength, flexibility, sensitivity or resistance to tissue ingrowth, coefficient of friction, or other properties known to affect the implant-tissue interface, the mechanical behavior of the implant, or both.

[0052] As described herein, the pitch density of a filament braid refers to the compactness of the filaments forming the braid. For example, a braid may have a higher or lower density of pitches based on the spacing between the filaments, the angle between two or more filaments of the braid, or other arrangements of one or more filaments of the braid. For example, Figure 3BAs shown, at least one filament braid 324 (i.e., filament) of diameter "d" (including at least segments 324a, 324b, 324c, and 324d) is braided (or alternatively woven) to define a hole "a" defined by sides having widths "w1" and "w2" and being arranged at angles "θ" and "θ'" "θ" and "θ'" relative to each other. The pitch density can be defined based on the smaller of "p1" and "p2", each of which can be defined as the sum of the maximum distance between the filament segments on the opposite sides defining the hole a and the diameter d of the filament braid 324, respectively. Therefore, the pitch density can be affected by changing one or more of w1, w2, θ or θ'. Although not shown in the drawings for simplicity, it can be further envisioned that various filaments of different diameters can be additionally woven into the stent according to the present disclosure, and such different diameters can additionally or alternatively affect the pitch density.

[0053] As described herein, the weaving pitch angle can be defined by the range of internal relative angles of the individual holes formed by the filaments. For example, the weaving pitch angle can be defined by the larger of θ or θ', or the weaving pitch angle can be defined by the angle of the hole most directly opposite the longitudinal axis of the stent (such as the axis AA of the stent 202). For example, in Figure 3B In the illustration of , hole a is set to be offset from axis AA. θ is more (e.g., more directly) relative to axis AA than θ'. Therefore, the weaving pitch angle of hole a can be limited by θ' or defined as θ'. Although not shown for simplicity, it is currently expected that various embodiments may include one or more weaving pitch angles along its range. For example, at least one retaining member and / or saddle region of the stent may include a weaving pitch pattern that is different from the weaving pitch pattern of other parts of the stent. For example, a varying weaving pitch angle can provide alternative retention strength and / or flexibility along the length of the stent.

[0054] As described herein, a weave pattern refers to how segments of filaments are woven together and / or oriented relative to each other. For example, a weave pattern can include a particular over:under pattern, where a segment can pass over a first number of intersecting segments and then pass under a second number of intersecting segments. For example, Figure 3BA 1:1 weave pattern may be included, where segment 324a passes over a segment (segment 324b) and then passes under a segment (segment 324c). Likewise, segment 324d passes over a segment (segment 324b) and then passes under a segment (segment 324c). Various additional or alternative weave patterns are presently contemplated, such as, for example, the 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 2:2, 2:3, 2:4, 2:5, 2:6, 2:7, 2:8, 2:9, 2:10, 3:3, 3:4, 3:5, 3:6, 3:7, 3:8, 3:9, 3:10, 4:4, 4:5, 5:5, 5:6, 5:7, 5:8, 5:9, 5:10, 6:6, 6:7, 6:8, 6:9, 6:10, 7:7, 7:8, 7:9, 7:10, 8:8, 8:9, 8:10, 9:9, 9:10, and 10:10 weave patterns.

[0055] Some embodiments may include multiple weave patterns. For example, one or more of the retaining members or saddle regions may include a different weave pattern than another portion of the stent. In another example, various filaments or segments of filaments may include alternative weave patterns. For example, segment 324a may include a 1:1 weave pattern, such as Figure 3B As shown, however, filament 324d can be passed over an additional segment (not shown in the drawings for simplicity) immediately after segment 324c, thereby comprising a 1:2 weave pattern. Embodiments are not limited in this context. For example, a varying weave pattern can provide alternative retention strength and / or flexibility along the length of the stent.

[0056] Stent 302 includes retaining members 310, 312 having a higher density of filament pitch (i.e., a tighter weave) than the filament pitch of the middle region 308, the saddle region 318, and / or the saddle region 320. Without wishing to be bound by any particular theory, it is believed that a portion of the stent body having a higher density of filament pitch can contribute to a higher radial strength (i.e., the ability to withstand radially inwardly applied pressure without collapsing) than a corresponding portion of the stent body having a lower density of filament pitch. For example, retaining members 310, 312 can include a higher radial strength than the middle region 308.

[0057] The stent 302 additionally includes retaining members 314, 316 having a pitch with a lower density (i.e., a looser weave) than the pitch of the filaments of the middle region 308, the saddle region 318, and / or the saddle region 320. Therefore, the radial strength of the retaining members 314, 316 can be lower than one or more of the retaining members 310, the retaining members 312, the middle region 308, the saddle region 318, and / or the saddle region 320. In some embodiments, the stent portion (such as retaining members 314, 316) can be configured to interface with the tissue atraumatically based on a lower pitch density. For example, the retaining members 314, 316 can have the following combined advantages: anti-displacement due to a relatively wide diameter; and improved compliance with the attached or engaged tissue and reduced trauma to the attached or engaged tissue due to a relatively low pitch density. The present embodiment is not limited to this.

[0058] Various embodiments include retaining members having one or more geometric features, including stent wall angles, shapes, radii of curvature, etc., which may contribute to the pull-out strength of the corresponding retaining member. Figure 4A An example of an outline of a retaining member 400 (such as any of retaining members 110, 112, 210, 212, 310, 312) is depicted, for example, as shown along Figure 2 As shown, the plane A' is observed parallel to the axis AA. Figure 4A As shown, the retaining member 400 may include one or more of the angles "γ1", "γ2", "γ3", "γ4", "γ5", "γ6", "γ7", ​​or "γ8" (collectively referred to herein as "γ1-8", which will be understood to refer to any or each of "γ1, γ2, γ3, γ4, γ5, γ6, γ7, or γ8) defined by corresponding adjacent segments of the stent wall forming the retaining member 400. Although in Figure 4A As shown in FIG. 1A and FIG. 2A as approximations, each of γ1-8 may be less than or greater than 90 degrees.

[0059] In various embodiments, the retention strength and / or pull-out force of the retaining member 400 may be higher depending on the sharpness of one or more of γ1-8. For example, the displacement of the retaining member 400 from within the tissue may require longitudinal stretching and / or deformation of the retaining member 400 (e.g., in order to reduce its maximum diameter, such as D2 or D3 as described above). The more acute angle γ1-8 may correspond to an adjacent segment of the stent wall that is defined therein, which is oriented to produce a force opposite to this lateral deformation. For example, it should be understood that if one or both of γ2 and γ4 are less than 90 degrees, the directional force "F1" applied to the retaining member 400 (e.g., which can be applied by further pulling the right side of the retaining member 400 to the right) can result in an opposite directional force "F2" applied by the segment of the wall extending between γ2 and γ4. Therefore, the opposite force F2 can resist the deformation of the retaining member 400 and the resulting displacement.

[0060] γ1-8 may each include the same angle, or one or more of γ1-8 may include at least one angle that is different from each of the others. Although for simplicity, the retaining members herein are shown as being circumferentially symmetrical (e.g., around axis AA), it is currently further contemplated that one or more stents may include a retaining member that includes an asymmetric cross-section that is orthogonal to a longitudinal axis extending therethrough (e.g., axis AA). For example, γ1 and γ5 may include angles that are different from each other, γ1 and γ2 may include angles that are different from each other, Y3 and Y7 may include angles that are different from each other, or any other combination of Y1-8 may include angles that are different from each other.

[0061] Thus, the pull-out force of the retaining member can be customized based on its internal angle. Additionally or alternatively, it can be appreciated that a sharper angle Y1-8 can reduce the conformity of the retaining member 400 relative to the abutting or engaging tissue, which in some embodiments can allow the retaining member 400 to snap onto and / or into the abutting or engaging tissue more effectively.

[0062] Similarly, it will be appreciated that more obtuse angles Y1-8 (i.e., greater than 90 degrees) can reduce the corresponding retention force of retention member 400 and / or increase the conformity (conformity) of retention member 400 to abutting or engaging tissue. For example, one or more of Y1-8 can be designed to be more obtuse than in alternative configurations in order to reduce trauma of retention member 400 to abutting or engaging a corresponding portion of tissue.

[0063] The intervening portion of the stent wall between the respective γ1-8 may extend directly between them, such as a straight line segment (e.g. Figure 4A ) or non-straight segments (such as Figure 4BIn some embodiments, the intermediate segment may include one or more curves, for example, defining any number of additional inflection points, angles γ9-x, where x represents any positive integer, etc.

[0064] For example, Figure 4B An example of a profile of one side of a retaining member 450 (such as any of retaining members 110, 112, 210, 212, 310, 312) taken along half of a plane A' that intersects axis AA is depicted. Retaining member 450 includes various inflection points n1, n2, n3, n4, n5, which are points along the curvature direction of retaining member 450 that change (i.e., the stent shape transitions between any two of the concave, convex, and straight portions). Retaining member 450 may include inflection points for any positive integer y. Although not shown for simplicity, Figure 4B , but in retaining member 450 , angles γ1, 2, 3 . . . x may be defined between tangent lines extending through inflection points that are closest to each other.

[0065] The segment extending between any one of γ1, 2, 3 ... x and / or n1, 2, 3 ... y may include one or more smooth curves, each of which may include at least one inner radius of curvature. In some embodiments, the various curves of the stent wall may be approximated based on the approximate radius of curvature they define. For example, the intersections between the curves are indicated as c1, c2, c3, c4, and c5 along the left retaining member 450, where each of n1-y additionally indicates the intersection of adjacent curved portions, but any curve of a positive integer z may be defined within the retaining member 450. The dashed circles superimposed on the various defined curves of the retaining member 450 (e.g., between n1 and c1, between c1 and c2, between c2 and n2, between n2 and c3, between c3 and c4, between c4 and c5, and between c5 and n3) approximate the corresponding curves, and each dashed circle includes a corresponding radius (not shown for simplicity) defining the radius of curvature of the corresponding curve. Any or each curve of the retaining member 450 may include the same or different radii of curvature.

[0066] As described above with respect to retention member 400, retention member 450 can be symmetrical or asymmetrical. For example, each side of retention member 450 can include similar and / or different inflection points, curves, radii of curvature, etc.

[0067] Figures 5A-5M Additional examples of profiles of a retention member, such as any of retention members 110, 112, 210, 212, 310, and 312, positioned between saddle regions of a stent, taken along half of a plane A' that intersects axis AA are depicted. Figures 5A-5MEach of includes two saddle regions 502, 504, each of which may correspond to the saddle region 118 and the middle region 108, 208, 308 or the middle region 108, 208, 308 and the saddle region 120, respectively. Figures 5A-5M Each of the brackets further includes a respective portion 506 (such as n1-5, for simplicity, Figures 5A-5M For simplicity, Figures 5A-5M The subsequently described portions 506 will be referred to as 506a, 506b, 506c, 506d, etc. However, it should be understood that any number and / or configuration of portions 506 may be included in a retaining member configuration according to the present disclosure.

[0068] about Figure 5A , the saddle region 502 can extend through portion 506a at an approximately right angle into portion 506b. In this example, the saddle region 502 and portion 506b form a concave curve with a small radius of curvature (e.g., less than 0.2 mm), which can be more or less a fold (i.e., forming an internal angle at a single point corresponding to 506a). Portion 506b may include straight edges extending transversely to (e.g., substantially perpendicular to) a longitudinal axis extending through the stent (such as axis AA). Thus, portion 506b can form faces 154, 160, 164, 166, 254, 260, 264, 266 as described above. In various examples, portion 506b can have a length between 10% and 300% of the diameter of the stent. Portion 506b can then extend into portion 506c. In Figure 5A , portion 506c curves convexly over the stent lumen to reduce in diameter to approximately the diameter of saddle region 504, where portion 506c is connected to saddle region 504 via portion 506d. Portion 506d includes a concave curve with a tight radius of curvature as discussed with respect to portion 506a.

[0069] Therefore, having Figure 5A Each side of the retaining member of the illustrated construction may be viewed as having an approximate half "D" shape, with portion 506c serving as one or both of one of faces 154, 160, 164, 166, 254, 260, 264, 266 and one of cylindrical regions 260, 270 as described above. It should be appreciated that Figure 5AThe configuration of the saddle region 502 can thus present one or more benefits over alternative configurations, such as greater resistance to migration of the retaining member in the direction of arrow "A" compared to in the direction of arrow "B". The difference in migration tendency can be based on the inconsistency of the combination of the saddle region 502, portion 506a and / or portion 506b with the natural shape (not shown) of the abutting or engaging tissue or one or both of the conformity of portion 506c with the natural shape or the tendency of the abutting or engaging tissue to return to its natural shape. For example, the conformity of portion 506c with the abutting or engaging tissue can be achieved based on a gradual change in its diameter along its length.

[0070] Figure 5B Another example of a retaining member is shown having two sides similarly configured to resist forces in the same direction as each other. Figure 5B 506a, which extends concavely outward with a relatively wide radius of curvature to form a wall, such as one of the faces 154, 160, 164, 166, 254, 260, 264, or 266 described above. For example, portion 506a may have a radius of curvature that is 25-200% of the diameter of saddle region 502, saddle region 504, or both. Portion 506a then extends into portion 506b, which forms a convex curve into portion 506c, which may correspond to one of the cylindrical regions 268, 270 described above.

[0071] In various embodiments, portion 506a may extend concavely to the extent that it curves back over itself and / or saddle region 502, to the extent that portion 506b extends over a portion of portion 506a, saddle region 504, or both. Thus, portion 506a, portion 506b, or a combination thereof may not conform to a tissue surface abutting or engaging along at least portion 506c. As described above, the change in orientation and overlap of the stent wall between one or more of saddle region 502, portion 506a, and portion 506b may resist a pull-out force in the direction of arrow A via a combined force in portion 506b in the direction of arrow B.

[0072] Portion 506c may extend into portion 506d, which may be convexly curved to reduce diameter. Portion 506d may form one of faces 154, 160, 164, 166, 254, 260, 264, or 266 as described above. Portion 506d may extend convexly to the extent that it curves backward under itself and / or portion 506c. Thus, portion 506d may extend through portion 506e at an acute interior angle into saddle region 504.

[0073] It will be appreciated that the similar profiles of portions 506a, 506d can enable each of them to similarly resist forces in the same direction. For example, if the retaining member is subjected to a force in direction A, each of portions 506a, 506d can promote an opposite resistance in direction B. Thus, it is preferred that in environments where migration, displacement, or both are resisted in a single direction, such as Figure 5B The illustrated configuration may present improvements over alternative retaining members.The embodiments are not limited in this context.

[0074] Figure 5C Examples of can provide asymmetric resistance to migration and / or displacement in different directions. Figure 5C In the embodiment, one or more of the saddle region 502, the portion 506a, the portion 506b, and the portion 506c may be as described above with respect to Figure 5B However, portion 506c extends into portion 506e via portion 506d at a sharp convex curve having a relatively small radius of curvature, so that a fold may be approximated. Portion 506e may then extend into saddle region 504 at a relatively wide radius of curvature (e.g., more than two times, more than five times, more than seven times, or more than ten times wider than the radius of curvature of portion 506d).

[0075] It can be seen that Figure 5C The retaining member has a generally reflective type curvature change about a plane "B", which may be orthogonal to axis AA as described above. For example, while the first side of the retaining member includes a recessed section (portion 506a) starting from the saddle region 502, followed by a convex section (portion 506b), followed by a straight section (portion 506c), the second side of the retaining member includes a recessed section (portion 506e) starting from the saddle region 504, followed by a convex section (portion 506d), followed by a straight section (portion 506e). Thus, the two sides of the retaining member may be configured to resist migration and / or displacement in opposite directions to each other. For example, the first side may resist migration and / or displacement in direction A more strongly than the corresponding other side, and the second side may resist migration and / or displacement in direction B more strongly.

[0076] However, the geometry of the curves about plane B' between the two sides of the retaining member may be viewed as being different, for example, in the radius of curvature of the respective portions. Without wishing to be bound by any particular theory, it is believed that the more acute internal angle of portion 506d, as opposed to portion 506b, may allow it to latch into and / or onto abutting or engaged tissue, increase friction against abutting or engaged tissue, and / or promote a component of resistance along the longer protrusion along axis AA as described above, which may further improve its corresponding resistance to migration and / or displacement. Thus, Figure 5CThe retaining member may thus be configured to asymmetrically resist migration and / or displacement between its sides.

[0077] The configuration of the retaining member with asymmetric resistance can achieve customized engagement of the stent with the tissue being abutted or engaged based on the needs and / or mechanical properties of the tissue or target tissue. Figure 5C The example saddle region 504 can be positioned along the stenosis S as described above so as to utilize the retention member based on its asymmetric side to allow the risk of the stent migrating along arrow B to be lower than the risk of migrating along arrow A. It is further contemplated that portions 506b and 506d can present an asymmetric tissue gripping interface, which can be selected based on the ability and / or sensitivity of the tissue to be respectively abutted or engaged to withstand such gripping. For example, based on the risk of further inflaming or irritating the tissue with contact with portion 506b being lower than contact with portion 506d, a configuration such as Figure 5C The retaining member is configured to allow saddle region 502, but not saddle region 504, to be placed across an inflamed area or other sensitive target area. Embodiments are not limited in this context.

[0078] Go to Figure 5D , examples of retaining members may include various straight portions transverse to axis AA as described above. Saddle region 502 extends through portion 506a at an acute internal angle into portion 506b, which thus bends back on the surface of saddle region 502. Portion 506b continues through portion 506c at an acute internal angle into portion 506d extending above and beyond, which portion 506d may be substantially parallel to saddle region 502 and / or saddle region 504 and may correspond to one or more of cylindrical regions 268, 270. Portion 506d extends through portion 506e at an acute internal angle into portion 506f, which thus bends under at least a portion of portion 506d before wrapping back through portion 506g at an acute internal angle into saddle region 504, which additionally extends under and beyond portion 506f.

[0079] In some embodiments, the angles formed by the tangents of the saddle region 502 and the portion 506b and the tangents of the saddle region 504 and the portion 506f can be the same, and / or the angles formed by the tangents of the portion 506b and the portion 506d and the tangents of the portion 506d and the portion 506f can have the same magnitude (for simplicity, the tangents and angles are not shown in the figure). In some embodiments, each of the angles formed by the tangents of the saddle region 502 and the portion 506b, the tangents of the saddle region 504 and the portion 506f, the tangents of the portion 506b and the portion 506d, and the tangents of the portion 506d and the portion 506f can have the same or substantially the same magnitude, which can be, for example, at least 45 degrees and less than 90 degrees.

[0080] Although Figure 5D The example is depicted as portions 506a, 506c, 506e, and 506d including sufficiently small radii of curvature so that the retaining member is approximately trapezoidal in shape (i.e., having different corner areas at portions 506a, 506c, 506e, and 506d), but alternative embodiments may include larger radii of curvature in all or any of portions 506a, 506c, 506e, and 506d. For example, it will be appreciated that in Figure 5D Increasing the radius of curvature of portions 506a, 506c, 506e, and 506d in the example of FIG. 5 may give the retaining member an hourglass shape. The embodiments are not limited in this context.

[0081] Figure 5D Examples of include changes in the type of reflection of the curve about plane B', as described above for Figure 5C However, Figure 5D The example also includes the reflection geometry of the portion around plane B'. Therefore, Figure 5D Each side of the retaining member may be configured to equally resist a corresponding reflective force without migration and / or displacement.

[0082] Figure 5E Contains similar to Figure 5D , but in which the intervening straight section is not located between the concave and convex portions. Instead, the saddle region 502 extends into portion 506a, which curves concavely into portion 506b. Portion 506b continues convexly into portion 506c, which may correspond to one of the cylindrical regions 268, 270 described above. Portion 506c extends into portion 506d, which curves convexly into portion 506f. The saddle region 504 extends from portion 506f. Thus, Figure 5D The example shown in can be viewed as having approximately a "Z" shaped side, whereas Figure 5EAn example of may thus have approximately “S” shaped sides.

[0083] Although Figure 5D The example of describes the interior angle defined by tangents to adjacent straight line portions as being at least 45 degrees and less than 90 degrees, but Figure 5E Examples of may include an interior angle defined by any or each of portions 506a, 506b, 506d, or 506e of nearly any magnitude. For example, it can be seen that the curves of portions 506a, 506b, 506d, and 506e as shown define an angle of approximately 0 degrees because they each wrap, curl, or fold back so as to extend in substantially the same direction at either of their respective ends. In an alternative example (not shown), segments such as portions 506a, 506b, 506d, and / or 506e may include a larger interior angle (e.g., 0 to 90 degrees) so as to extend in opposite lateral directions at either of their respective ends.

[0084] In some examples (not shown), segments such as portions 506a, 506b, 506d, and / or 506e may be coiled, curled, or folded back to extend rearwardly at each end in a cross direction (e.g., in a manner greater than a semicircle). Thus, portions 506b, 506d may begin with a diameter that is less than the maximum diameter of the corresponding portion 506a, 506e (e.g., they may sag downwardly above or overhang the corresponding saddle regions 502, 504).

[0085] Various examples (not shown) may include, for example, Figure 5E The curved portion, but with Figure 5D The intervening straight line portion. The embodiments are not limited in this context.

[0086] It will be appreciated that the winding, curling or folding of the curved portion itself may contribute to a higher resistance of the corresponding portion to straightening, for example due to the greater force required to overcome internal opposing forces within the portion in order to be able to change the direction of the end and thereby extend the portion longitudinally into the stretched configuration. Fig. 5F An example of includes portion 506e that is folded upon itself to create a protrusion extending over saddle regions 504, wherein portion 506f extends between saddle regions 504. Fig. 5F In the example of FIG. 5 , saddle region 502 extends at approximately right angles through portion 506a into portion 506b, and portion 506b extends at approximately right angles through portion 506c into portion 506d. Portion 506c then continues into portion 506e discussed above.

[0087] Figure 5GExamples of further include an overhanging segment extending above the saddle region but formed by a portion defining an interior angle slightly greater than 0 degrees. In particular, the saddle region 502 extends into portion 506a, which is concavely bent to the beginning of portion 506b, thereby defining an interior angle between 0 degrees and 90 degrees. Therefore, portion 506b extends radially outward from portion 506a, saddle region 502, or both, and convexly bends backward on itself to meet portion 506c. Then, portion 506c can extend to portion 506d. In various examples, portion 506c can be one of the cylindrical regions 268, 270 as described above, and in some examples can be substantially parallel to the saddle region 502, the saddle region 504, or both. Portion 506d defines an obtuse angle extending between portion 506c and portion 506e. Therefore, portion 506e is inclined toward the saddle region 504, which is connected to the saddle region 504 at a concave obtuse angle by portion 506f. Without wishing to be bound by any particular theory, it is believed that Fig. 5F The opposite of those examples, Figure 5G A relatively larger radius of curvature and / or a smaller angular change between corresponding portions of the examples can result in a lower pull-out force, a tissue interface that more closely conforms to the shape of the abutting or engaging tissue, or both.

[0088] about Figure 5H , the saddle region 502 may extend into the concave surface of portion 506a, which may extend into portion 506b. Portion 506b includes a straight edge extending backward at an angle less than 90 degrees on the saddle region 502. In some embodiments, the inner wall surface may extend a distance of 0.0-5.0 mm along the longitudinal axis of the cylindrical saddle region toward its vertical center plane. For example, portion 506b may extend 0.5-1.5 mm, 0.2-2.0 mm, etc. on the saddle region 502. However, in other embodiments consistent with the present disclosure, a portion of the retaining member may extend a greater distance on the saddle region as described herein. Portion 506c includes a convex curve extending between portion 506b and portion 506d. Portion 506d may include a portion parallel to the surface of the saddle region 502, and may correspond to one of the cylindrical regions 268, 270 as described above. Portion 506d extends into portion 506e, which may include a convex surface. In various embodiments, the inner radius of curvature defined by portion 506e can be greater than the inner radius of curvature defined by portion 506c. However, it will be appreciated that alternative embodiments may include varying relative radii of the circumference between the portions. One or more convex and / or concave surfaces as described herein may include the same or different curvature finish angles, circumferential radii, lengths, other features, or any combination thereof.

[0089] about Fig.5IIn the exemplary embodiment shown, the retaining member may include Figure 5H The saddle region 502 and portions 506a, 506b are similarly described. Portion 506b may then similarly extend into portion 506c. However, as Fig.5I The portion 506c shown may have a Figure 5H The larger curvature shown is completed at an angle, for example, such that it extends directly into portion 506d. Portion 506d may include a concave surface connecting portion 506c to saddle region 504. In some embodiments, portion 506c or other segments including one or more portions may include a radius of curvature that varies along its length, such as a non-uniform and / or otherwise undulating curve.

[0090] Figure 5J Another exemplary embodiment is depicted wherein the retaining member may include Figure 5H The saddle region 502 and portions 506a, 506b, 506c, 506b are similarly described. However, as Figure 5J The portion 506e shown extending from the portion 506d may include, for example Figure 5H The larger radius of curvature shown. Figure 5J 506f extending from portion 506e may include a straight edge extending from portion 506e rearwardly toward saddle region 502. Portion 506f may extend into portion 506g, which is located at Figure 5J Portion 506c may extend into saddle region 504. In some embodiments, the angle defined by portion 506f and saddle region 504 or the angle of portion 506g may be less than 90 degrees.

[0091] Figure 5K A further exemplary embodiment is shown in FIG. Figure 5K 506a may include a concave curve extending into the straight edge of portion 506b. Portion 506b may extend into a convex curve of portion 506c, which in turn may extend into portion 506d. Portion 506d may correspond to one of cylindrical regions 268, 270 as described above. Portion 506d may extend into portion 506e, which may include a convex curve. Portion 506e may in turn extend into portion 506f, which may include a concave section. Portion 506f may extend into saddle region 504. However, at least one of portions 506e, 506f may include a smaller radius of curvature, for example, as described with respect to Figure 5HIn some embodiments, the concave or convex curve of at least one portion may include a sufficiently tight radius of curvature to include a crease or other fold. Without wishing to be bound by any particular theory, the invention relates to the invention comprising: Figure 5H Compared with the embodiment of the retaining member structure shown in Figure 5K Embodiments of the retention member configuration shown in can therefore have greater pull-out force, more stable interaction with tissue abutting or engaging along at least portion 506e, or both.

[0092] about Figure 5L For example, the retaining member may include Figures 5A-5K For example, portions 506d and 506e may include one or more similarities to portions 506b and 506a, respectively, as described with respect to FIG. 1 . Figure 5L The portion 506e extends into the saddle region 504, and Fig. 5F The portion 506a extends into the saddle region 502. Figure 5L In the example shown, portion 506a, which continues from saddle region 502, can extend or dip into a narrower diameter than saddle region 502. Portion 506b can extend from portion 506a and bend backward to have a larger diameter than saddle region 502. In various examples, portion 506b can extend backward over one or both of portion 506a and at least a portion of saddle region 502. Portion 506c extends from portion 506b and bends convexly to meet portion 506d. Various portions as described herein can include a sufficiently small radius of curvature to form a right angle or a relatively right angle. For example, as Figure 5L The portion 506e shown in FIG. 5 may include a radius of curvature of 0.0-0.5 mm, such as 0.1-0.3 mm.

[0093] Reference now Figure 5M In some examples, the retaining member may include two or more parallel surfaces. For example, portion 506b extending from saddle region 502 through portion 506a and portion 506f extending from saddle region 504 through portion 506g may include parallel or substantially parallel surfaces. Portion 506d may extend between portions 506b and 506f, connected to portion 506b via portion 506c and connected to portion 506f via portion 506e. In some examples, portion 506d may correspond to one of cylindrical regions 268, 270 as described above.

[0094] Although parts 506b, 506f are Figure 5M506a and 506g are shown as extending substantially perpendicularly from one or both of the saddle regions 502, 504 (e.g., substantially perpendicularly from the axis AA as described above), but the surface of the retaining member according to the present disclosure may also be transverse to one or more of the saddle regions 502, 504 or the axis AA in other ways. For example, portions 506a and 506g may be complementary in other ways, rather than each defining a 90 degree internal angle as shown. For example, portion 506a may define an internal angle of 30 degrees and portion 506g may define an internal angle of 150 degrees, portion 506a may define an internal angle of 45 degrees and portion 506g may define an internal angle of 135 degrees, portion 506a may define an internal angle of 50 degrees and portion 506g may define an internal angle of 130 degrees, and so on. In other embodiments, portions 506a and 506g may not be complementary, such as with respect to Figure 5L The portions 506b and 506e described above can then be used to connect the corresponding portions using any number of portions of the stent wall to form a retaining member, which can in some embodiments form a complete wall or partition between the lumen (e.g., lumen 122) and the exterior of the stent. The embodiments are not limited in this context. The embodiments are not limited in this context.

[0095] Although about Figures 5A-5M Various parts are described, but it should be understood that various embodiments may include similarities and / or differences to one or more of the examples shown. For example, the retaining member may include more or fewer parts than described above, and any portion thereof may include at least one recess, protrusion, straight edge, or any combination thereof. A portion may extend toward the first portion or the 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. In addition, with respect to Figures 5A-5M The dimensions and / or orientation of any portion described may apply to other portions described therewith, alternatively or in combination, or to portions and / or retaining member profiles that are otherwise within the scope of the present disclosure. Additionally or alternatively, the profile of the retaining member may vary rotationally about an axis. For example, although not shown for simplicity, the retaining member may include an asymmetric cross-section about axis AA in longitudinal plane A', as described above. For example, when viewed above axis AA in plane A', the cross-section of the retaining member may include a cross-section about axis AA, as described above. Figure 5A The shape described above, however, when viewed below the axis AA in plane A', the cross-section of the retaining member may include as described with respect to Figure 5B Additionally or alternatively, it is currently envisaged that Figures 5A-5M Any combination of the described cross-sectional shapes or features. The embodiments are not limited in this context.

[0096] In some embodiments, a smaller radius of curvature in each portion can contribute to a higher holding strength of the corresponding holding member. Fig.5I The configuration shown in can have Figure 5M Thus, embodiments may be configured according to various retention member strength requirements necessary for at least one particular surgery, tissue, or other consideration.

[0097] In addition, it can be imagined that Figures 5A-5M The various retaining member configurations described may provide additional benefits over conventional devices. For example, various retaining member configurations may create space between the tissue being abutted or engaged and the saddle region of the stent. For example, a configuration such as Figure 5D-5L Retention members of those configurations may, by virtue of their overlapping portions, retain the abutting or engaged tissue away from at least a portion of one or both of the saddle regions 502, 504. Thus, the respective retention members may be configured to reduce contact of one or both of the saddle regions 502, 504 with at least one target region along the abutting or engaged tissue, which may thereby reduce the risk of inflammation of the at least one target region due to its interfacial engagement with the stent.

[0098] Various stents according to the present disclosure may include, for example, Figures 5A-5M The plurality of retaining members described in any one of the above can be configured to completely separate the tissue in contact or engagement with the saddle-shaped area extending therebetween. For example, the retaining members 110, 112 described above can each include the following: Figures 5A-5M Any of the configurations described, and can be configured to keep the tissue abutting or engaging completely away from the middle region 108. The retaining member can be configured to keep the tissue abutting or engaging at least 1mm, 2mm, 3mm, 4mm or 5mm away from the saddle region, although distances less than 1mm, greater than 5mm and any intermediate distances are currently also considered. In some embodiments, the retaining member can be configured to retain a therapeutic agent, such as a growth medium, a sealant, a tissue scaffold, an anti-inflammatory agent, an adhesive, etc., along the saddle region and between the retaining members, so that the tissue abutting or engaging is exposed to the therapeutic agent. For example, the retaining members 110, 112 can be configured to keep the tissue abutting or engaging separated from the middle region 108 so that a space is defined between them, which space can be preloaded with a therapeutic agent or subsequently filled with a therapeutic agent, for example, via an injection needle extending through the tissue or through the wall of the support. The various embodiments are not limited in this context.

[0099] Figures 6A-6K1 shows a side view of an additional example of a retaining member that may be in a stent according to the present disclosure, such as any of retaining members 114, 116, 214, 216, 314, and 316. However, as with respect to Figures 6A-6K The retaining member of the described construction may include a saddle region 602 that extends from only one side. For example, the saddle region 602 may correspond to one of the saddle regions 118, 120, 318, 320, 502, or 504 described above. Figures 6A-6K Each of the above also includes a defined at a support wall inflection point (such as n1-5 described above, for simplicity, Figures 6A-6K For simplicity, Figures 6A-6K The subsequently described portions 604 will be referred to as 604a, 604b, 604c, 604d, etc. However, it should be understood that any number and / or configuration of portions 604 may be included in a retaining member configuration according to the present disclosure.

[0100] Various examples of retaining members may include a flared end portion 606 having an end diameter that is greater than an end diameter of the saddle region 602. Fig. 6A , the portion 604a extending from the saddle region 602 is concavely curved outward to have a wider diameter than the saddle region 602, and the portion 604b extends from the portion 604a to further increase the diameter. Fig. 6A The portions 604a, 604b in the middle form a continuously flared end portion 606.

[0101] Various embodiments may alternatively include at least one flared end having a stepped, undulating, or other varying configuration. Figure 6B 6, portion 604a continues concavely from saddle region 602 into portion 604b, and portion 604b curves convexly to form a first step 608a. From portion 604b, portion 604c curves concavely outwardly to portion 604d, and portion 604d curves convexly to form a second step 608b. The retaining member may include any number of steps, such as 1, 2, 3, 4, 5, or more. Although not shown for simplicity of the figure, a step or other surface feature as described herein may include one or more straight portions, such as between adjacent concave and convex portions, or between intersecting concave or convex portions as described herein.

[0102] Although you can see Figure 6B The diameter of the exemplary retention member of increases uniformly along its length, but various embodiments may include a retention member that includes at least one section of the retention member having a decreasing diameter. Figure 6C, portion 604a extends from the saddle region 602 and together with portion 604b forms a first step 608a, as described with respect to Figure 6B Similarly, portion 604c extends from portion 604b and forms a second step 608b together with portion 604d, as described with respect to Figure 6B However, it can be seen that each of portions 604b and 604d defines a ratio Figure 6B Without wishing to be bound by any particular theory, it is believed that the inward curling of each of these stepped ends can help reduce the risk of traumatic interference with tissue abutting or engaging and / or more closely approximate the shape of tissue abutting or engaging.

[0103] Fig.6D The exemplary retaining member of includes a portion 604a extending from the saddle region 602 to a portion 604b. Fig.6D Portion 604a shown includes a concave angle of approximately 90 degrees, so that portion 604b extends approximately perpendicular to axis AA as described above. However, 604a may include an alternative internal angle so that portion 604b is oriented transversely relative to axis AA and / or saddle region 602. Portion 604c connects portion 604b to portion 604d at a second angle. Although the internal angle of portion 604c is shown as approximately 90 degrees, portion 604c may define any angle. In various examples, the angles defined by portions 604a and 604c may complement each other, for example, so that saddle region 602 and portion 604d extending from portion 604c may be substantially parallel to each other.

[0104] In addition, although the curvature radius of the portions 604a, 604c is Fig.6D The radius of curvature is shown as being substantially small enough to form a fold or crease, for example 0.0-0.5 mm, such as 0.1-0.3 mm, but larger radii of curvature are presently contemplated, for example 0.5-5.0 mm or larger. The embodiments are not limited in this context.

[0105] Figure 6E-6I A retention member is depicted that includes a protrusion 610 that extends circumferentially around the stent. Figure 6E-6F , portion 604a extends from saddle region 602 and curves concavely to portion 604b. Portion 604b curves convexly to define the maximum diameter of protrusion 610 (the diameter is not shown in the drawings for simplicity). From portion 604b, portion 604c curves concavely to extend to portion 604d at end 606 of the stent. Although Fig. 6E Examples include a portion 604d and / or an end portion 606 having a diameter substantially the same as the diameter of the saddle region 602, but Fig. 6FThe retaining member may include a portion 604d and / or an end 606 having a diameter greater than the diameter of the saddle region 602, for example, 10%, 20%, 30%, 40%, 50%, or 60% greater than the diameter of the saddle region 602 (the diameter is not shown in the drawings for simplicity). In other embodiments, the retaining member may include an end (such as end 606) having a diameter less than the diameter of the attached saddle region, for example, 10%, 20%, 30%, 40%, 50%, or 60% less than the diameter of the corresponding saddle region. The embodiments are not limited in this context.

[0106] exist Figure 6G In, with Fig. 6F In contrast, protrusions 610 are located at the end of the region of the stent where the diameter increases rather than at its beginning. Figure 6G 6, portion 604a curves outwardly from saddle region 602 to portion 604b having a diameter greater than saddle region 602. Portion 604c then curves further outwardly concavely to portion 604d, which then defines the maximum diameter of protrusion 610. Portion 604e may optionally curve radially inwardly to have a diameter less than the maximum diameter of protrusion 610, e.g., greater than or substantially equal to the maximum diameter of 604b.

[0107] Without wishing to be bound by any particular theory, it is believed that a retention member defined by a portion having a larger radius of curvature may include a tissue interface that is more gradual and / or an interface that more closely approximates a natural tissue surface than a retention member defined by a portion having a corresponding smaller radius of curvature. Figure 6H Describes the Figure 6G Examples of retaining members of various similar features described above, but wherein each curved portion includes a Figure 6G The correspondingly larger radius of curvature in the example. Figure 6G Compared to the example, Figure 6H Examples may include increased correspondence with the natural shape of the tissue being abutted or engaged, Figure 6G The example can be compared to Figure 6H examples are more securely contained within a tissue lumen, or both.

[0108] Although FIG. 6E to FIG. 6H The examples of each include only a single protrusion, but embodiments including multiple protrusions are also contemplated. For example, multiple protrusions 610 can extend circumferentially around the stent (not shown). Alternatively or additionally, the protrusions can be helically wrapped around the stent, such as Fig.6I As shown in the protrusion 612 of the stent. In other embodiments, one or more protrusions may not extend completely around the circumference of the stent, but may extend asymmetrically around a portion of the circumference of the stent. The embodiments are not limited in this context.

[0109] exist Figure 6J In the example of the embodiment of the present invention, portion 604a connects the saddle region 602 to portion 604b, which includes a straight edge extending radially outward from the saddle region 602, thereby forming an inclined portion 614. Portion 604b continues into portion 604c, which bends into portion 604d. Portion 604d includes a second straight edge, which can extend parallel to the saddle region 602, thereby forming a cylindrical region 616 of the stent. The inclined portion 614 and / or the cylindrical portion 616 can each individually or together include a longitudinal length that is at least one-quarter, one-third, one-half, two-thirds, three-quarters, or the same length as the length of the saddle region 602.

[0110] Optionally, portion 604e may then continue from portion 604d, reducing in diameter at the stent's end 606. Without wishing to be bound by any particular theory, it is believed that the reduction in diameter of the stent at its ends may reduce the risk of the stent atraumatically engaging tissue at or along the ends.

[0111] Figure 6K An example of a retaining member including an overlap region 618 is depicted, which can be formed by a portion of the stent being bent back upon itself. For example, portion 604a extends from saddle region 602 into portion 604b, which extends radially outward from saddle region 602. Although portion 604b is shown as being substantially orthogonal to the surface of saddle region 602, portion 604b can be disposed at a lateral angle to saddle region 602. Portion 604c can optionally extend from portion 604b so as to overlap at least a portion of portion 604b, portion 604a, saddle region 602, or any combination thereof.

[0112] Thus, in various embodiments, the overlap region 618 may present an atraumatic interface at the end 606 of the stent, a cupped or closed end at a gap defined along the surface of the saddle region 602, or both. The embodiments are not limited in this context.

[0113] A stent according to the present disclosure may be preformed using one or more retaining members as described herein, for example, by winding at least one filament braid 702 around a mandrel 704 to form a stent 706, such as Fig. 7A In various embodiments, the preformed configurations as described herein can include deployed configurations, expanded configurations, unconstrained configurations, and the like.

[0114] Mandrel 704 may include various washer-like portions, extensions, or other protrusions, such as washer-like portions 708 and 710 and angled protrusions 712 and 714, around which at least one filament braid 702 may be arranged and shaped, for example, by heat setting, to form a correspondingly shaped retaining member. For example, a filament braid may be shaped by shaping the filament braid around a correspondingly shaped protrusion of the mandrel. Figures 5A-5M and Figures 6A-6K Any retaining member described. In various examples, the mandrel 704 can include one or more grooves into which the at least one filament braid 702 can be aligned (not shown). In various embodiments, the at least one filament braid 702 can be wrapped around at least one protrusion (such as a screw 722) to form an end 716 and / or end 718 of the stent having a curved filament edge, such as the end 606, as shown. Figures 6A-6K shown.

[0115] like Figure 7B As shown in the cross-sectional view of FIG, one or more clamps 720 can be used to constrain at least one filament braid 702 to the surface of the mandrel 704 (e.g., during the heat setting process). Thus, the stent 706 can be formed to have precise dimensions according to the desired configuration, including diameter, width, radius of curvature, etc. The clamp 720 may include one or more components that can be clamped around the mandrel 704, slid on the end of the mandrel 704, or otherwise constrained around the mandrel 704.

[0116] It should be understood that various stents according to the present disclosure can be preformed, for example, around a mandrel 704, with one or more weaving pitches, weaving patterns, pore sizes, pore geometries, etc. as described above with respect to FIGS. 3-4B . For example, at least one filament braid 702 can be wrapped around one or more of the washer-like portions 708 and 710 and the inclined protrusions 712 and 714 at a different weaving pitch than another portion along the mandrel 704. The various embodiments are not limited in this context.

[0117] Various stents according to the present disclosure can be configured to transition between a first configuration and a second configuration, such as a delivery and deployment configuration, a constrained configuration and an expanded configuration, etc. In various embodiments, a stent according to the present disclosure can be loaded into a delivery system in a first configuration (e.g., a delivery or constrained configuration) and delivered to a target location (e.g., in or through one or more body tissues or lumens).

[0118] Figure 8An example of a delivery system 800 according to the present disclosure is depicted. A stent 802 (which may be a stent discussed herein or a stent of similar nature) may be constrained between an inner member 804 and an outer sheath 806, wherein the outer sheath 806 is slidably disposed around the inner member 804, the inner member 804 is slidably disposed within the outer sheath 806, or both.

[0119] In some embodiments, a tip 808 can be disposed at the distal end of the inner member 804. The tip 808 can be a tissue penetrating tip and can include one or more of a knife, an electrocautery tip, or other cutting elements.

[0120] The handle 810 can be disposed at a proximal end of one or both of the inner member 804 and the outer sheath 806. The handle 810 can be configured to effectuate displacement of one or both of the inner member 804 and the outer sheath 806 relative to one another.

[0121] The delivery system 800 can be generally used in conjunction with an endoscope, a non-limiting example of which is an endoscopic ultrasound (EUS) scope (not shown). For example, the delivery system 800 can extend through a working channel of the endoscope such that the handle 810 is accessible near the handle of the endoscope and the tip 808 extends through the working channel of the endoscope, such as into a body cavity of a patient.

[0122] Figures 9A-9E The use of delivery system 800 to deliver stent 802 to a target site and deploy stent 802 at the target site is shown. Figures 9A-9E , delivery of stent 802 within a single body lumen is shown, but delivery to alternative target sites is also presently contemplated, including end-to-end anastomosis, end-to-side anastomosis, etc. The embodiments are not limited in this context.

[0123] exist Fig.9A, the distal ends and tip 808 of the inner member 804 and the outer sheath 806 extend into a body cavity 900 defined by tissue 902, so that the stent 802 in the delivery configuration is positioned within the body cavity 900. The delivery system 800 can be positioned within the body cavity 900 so that the tip 808, the inner member 804, and / or the outer sheath 806 are positioned relative to the target location (e.g., a predetermined distance away from the target location). In various embodiments, the delivery system 800 or aspects thereof can be advanced until one or more markers 904 (e.g., markers 904a, 904b, 904c (not shown), etc.) along the outer sheath 806 are aligned with a first position "P1" within the body cavity 900, the first position "P1" corresponding to the desired position where the end of the stent 802 will be positioned once deployed. The marker 904 can include at least one colored, echogenic, radiopaque, or otherwise visualized material that can extend partially or completely around the circumference of the outer sheath 806. In some embodiments, the marker 904 can alternatively be positioned along the inner member 804 , or one or more additional markers can additionally be positioned along the inner member 804 .

[0124] When the tip 808, the inner member 804, and / or the outer sheath 806 are aligned with the position P1, the outer sheath 806 can be retracted proximally relative to the inner member 804, the inner member 804 can be extended distally relative to the outer sheath 806, or both, to release the distal end 906 of the stent 802 from between the inner member 804 and the outer sheath 806. The distal end 906 of the stent 802 can correspond to all or part of the stent end described above, such as the first end 104 or the second end 106.

[0125] like Fig. 9B As shown, when released from between the inner member 804 and the outer sheath 806, the distal end 906 of the stent 802 can be deployed to expand into the first retaining member 908, which can include any of the structures discussed herein (e.g., Figures 6A-6K shown in and / or relative to Figures 6A to 6K In some embodiments, first retaining member 908 can expand to have a diameter that is the same as or larger than lumen 900. For example, first retaining member 908 can expand tissue 902 to increase the diameter of lumen 900.

[0126] After deployment of the first retention member 908, the inner member 804 and the outer sheath 806 can be secured relative to each other (e.g., via locking of the handle 810, as described with respect to Figure 8), such that the delivery system 800 can be further positioned inside the body cavity 900. For example, the delivery system 800 can be positioned inside the body cavity 900 so that the stent 802 can be further partially deployed to form a second retaining member 910 at a second reference position "P2" inside the body cavity 900 and / or along the tissue 902. The second retaining member 910 can include a structure as discussed herein, such as Figures 5A-5M Any of the above and / or Figures 5A-5M Any of the retaining member configurations discussed herein.

[0127] The positioning of the delivery system 800 relative to P2 can be determined based on the visualization of the markers as described above at or near P2 before the second retaining member 910 is deployed. For example, the positioning of the marker 904b at P2 can indicate that the delivery system 800 is positioned inside the body cavity 900, so that the deployment of the second retaining member 910 will cause the second retaining member 910 to be positioned at P2. The marker 904b can be set along the inner member 804 and / or the outer sheath 806. For example, the markers 904 along each of the inner member 804 and the outer sheath 806 can be aligned with each other based on the sliding of the inner member 804 and the outer sheath 806 relative to each other, and the aligned markers 904 can be positioned relative to P2. Each embodiment is not limited in this context.

[0128] Once the delivery system 800 is positioned so that the deployed second retention member 910 will be properly positioned within the lumen 900, the inner member 804 and the outer sheath 806 may be unfixed relative to each other. Fig. 9C As shown, outer sheath 806 may then be further retracted relative to inner member 804, inner member 804 may then be further extended relative to outer sheath 806, or both, to continue to release a degree of stent 802 from between inner member 804 and outer sheath 806. Stent 802 may thereby be partially deployed to form second retention member 910 at a desired location.

[0129] In some examples, the intervention range of the stent body can be deployed between the first retention member 908 and the second retention member 910, such as the cylindrical saddle region 118 described above. One or both of the second retention member 910 and the intervention range of the stent body can be expanded to have the same or larger diameter as the lumen 900.

[0130] Fig.9DFurther retraction of the outer sheath 806 relative to the inner member 804, extension of the inner member 804 relative to the outer sheath 806, or both are shown to further partially expand the stent 802 to form the third retention member 912, for example, to form the third retention member 912 at a third reference position "P3" based on the positioning of at least one marker (not shown) before the third retention member 912 is deployed. In some embodiments, the inner member 804 and the outer sheath 806 can be fixed relative to each other after the second retention member 910 is deployed, and are not fixed relative to each other based on the positioning of at least one aspect of the delivery system 800 at P3. The third retention member 912 can be deployed based on the unfixation of the inner member 804 and the outer sheath 806 relative to each other. In some embodiments, a saddle region (such as the middle region 108, 208, 308) can be deployed between the second retention member 910 and the third retention member 912. One or both of the saddle region and the third retention member 912 can include a diameter at least as large as the diameter of the lumen 900. The third retaining member 912 may include a configuration as discussed herein, such as Figures 5A-5M Any of the above and / or Figures 5A-5M Any of the retaining member configurations discussed herein.

[0131] like Fig.9E As shown, after the third retaining member 912 is deployed, the outer sheath 806 can be further retracted relative to the inner member 804, the inner member 804 can be further extended relative to the outer sheath 806, or both, so as to completely release and thus deploy the stent 802 between the inner member 804 and the outer sheath 806. Therefore, the proximal end 916 can expand into the fourth retaining member 914. Similarly, as discussed above with respect to the deployment of other retaining members, the inner member 804 and the outer sheath 806 can be fixed relative to each other, and the delivery system 800 is positioned so that the deployment of the fourth retaining member 914 will occur at a fourth reference position "P4", at which point the inner member 804 and the outer sheath 806 can be unfixed relative to each other. One or more markers (not shown) can be used to position the delivery system 800 accordingly.

[0132] The fourth retaining member 914 may include a configuration as discussed herein, for example, as shown in any of 6A-6K and / or with respect to Figures 6A-6K A saddle region (such as cylindrical saddle region 120) can be deployed between third retaining member 912 and fourth retaining member 914. One or both of the saddle region and fourth retaining member 914 can include a diameter at least as large as the diameter of lumen 900.

[0133] In various embodiments, the deployment of one or more aspects of the stent 802 can include a shortening of the stent 802 (i.e., a reduction in its longitudinal length). For example, upon deployment, the stent 802 can shorten by up to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or more, including any percentages therebetween. The shortening of the stent 802 can cause one or more aspects of the stent 802 to align with corresponding reference or target positions within the lumen 900. For example, the shortening of the stent 802 can cause the first retaining member 908 to align with position P1, the second retaining member 910 to align with position P2, the third retaining member 912 to align with position P3, and / or the fourth retaining member 914 to align with position P4. In some embodiments, the stent 802 can be positioned so that each aspect is aligned with one or more reference positions (such as P1, P2, P3, or P4) before the stent 802 is fully shortened. For example, the first retaining member 908 may be aligned with the position P1 after only the distal end 906 is deployed (i.e., before the proximal end 916 is deployed). Due to the shortening of the stent 802, the deployment of the subsequent aspect of the stent 802 (i.e., the proximal end 916) may cause the deployed aspect to slide relative to the tissue 902 and / or reposition the tissue 902. For example, as the stent 802 shortens, the friction fit of the first retaining member 908 with the tissue 902 may cause the abutting or engaging surface of the tissue 902 to expand to remain positioned along the first retaining member 908.

[0134] In some embodiments, the shortening of the stent 802 can be limited by the opposing force applied by the tissue against or engaged. For example, the tissue 902 can apply a force opposite to the tension force applied to the distal end 906 by shortening the stent 802, so that when deployed in the tissue, the stent 802 is shortened less than when deployed outside the tissue (e.g., in a vacuum or empty space). It will be appreciated that the shortening amount of the stent can then be customized based on the interaction of the configuration of the stent with the tissue against or engaged. Therefore, the weaving pitch, weaving pattern, etc. as described above can be customized to affect the radial strength of at least a portion of the stent, thereby affecting the interaction of the stent with the tissue against or engaged, thereby achieving the desired shortening behavior of the stent when it is deployed in the tissue.

[0135] Although the reference positions P1, P2, P3 and P4 are Figures 9A-9E , but it will be appreciated that the reference position may alternatively or additionally be located along an alternative edge of a retaining member, along the length of one or more retaining members, or elsewhere. The embodiments are not limited in this context.

[0136] In accordance with the present disclosure, all devices and / or methods disclosed and claimed herein can be made and performed without undue experimentation. Although the devices and methods of the present disclosure have been described according to preferred embodiments, it is obvious to those skilled in the art that the steps or step sequences of the devices and / or methods and the methods described herein can be changed without departing from the concept, spirit and scope of the present disclosure. All such similar alternatives and modifications apparent to those skilled in the art are considered to be within the spirit, scope and concept of the present disclosure as defined by the appended claims.

Claims

1. Bracket, including: an elongated body configured to expand between a first constrained configuration and a second unconstrained configuration, The elongated body in the second unconstrained configuration comprises a first end, a second end, and a cylindrical saddle region extending therebetween, wherein: The first end portion includes a first retaining member and a second retaining member, and The second end portion includes a third retaining member and a fourth retaining member.

2. The stent of claim 1, wherein the second retaining member comprises a first, radially outwardly facing surface that is substantially cylindrical, or the third retaining member comprises a second, radially outwardly facing surface that is substantially cylindrical, or both.

3. The bracket of claim 2, wherein the second retaining member includes a first axially inner face connected to the first radially outward surface at a first corner, or wherein the third retaining member includes a second axially inner face connected to the second radially outward surface at a second corner, or both. 4 . The stent of claim 3 , wherein the first axially inner face comprises a curved profile, or wherein the second axially inner face comprises a curved profile, or both.

5. The stent of any one of claims 3-4, wherein the first corner comprises an internal angle of 90 degrees or less, or wherein the second corner comprises an internal angle of 90 degrees or less, or both.

6. The stent according to any one of claims 3 to 5, wherein the second retaining member is not covered along the radially outermost surface, or wherein the third retaining member is not covered along the radially outermost surface, or both.

7. The stent of any one of claims 3-5, wherein the first corner is uncovered, or wherein the second corner is uncovered, or both.

8. A stent according to any one of claims 1-6, wherein the first retaining member is configured to engage with a tissue interface along its entire first longitudinal length, or wherein the fourth retaining member is configured to engage with a tissue interface along its entire second longitudinal length, or both.

9. A stent according to any one of claims 1-7, wherein the first end includes a first cylindrical portion extending between the first retaining member and the second retaining member, or wherein the second end includes a second cylindrical portion extending between the third retaining member and the fourth retaining member, or both.

10. The stent of any one of claims 1-8, wherein the first and fourth retention members are each configured to atraumatically interface with tissue surrounding a radially outermost circumference of the respective retention member.

11. The stent of any one of claims 1-9, wherein the second and third retention members are each configured to atraumatically interface with tissue surrounding a radially outermost circumference of the respective retention member.

12. A stent according to any one of claims 1-10, wherein the stent is formed by at least one braided or woven filament, and in the second structure, the at least one braided or woven filament includes different pitch densities, angles or patterns at the first retaining member, the second retaining member, the cylindrical saddle area, the third retaining member or the fourth retaining member or any combination thereof.

13. A stent according to any one of claims 1-11, wherein the first retaining member has an asymmetric cross-section in a plane orthogonal to a longitudinal axis extending through the inner cavity of the slender body, or wherein the second retaining member has an asymmetric cross-section in a plane orthogonal to the longitudinal axis, or both.

14. A stent according to any one of claims 1-12, wherein the first retaining member has an asymmetric cross-section in a longitudinal plane parallel to a longitudinal axis extending through the inner cavity of the slender body, or wherein the second retaining member has an asymmetric cross-section in a longitudinal plane parallel to the longitudinal axis, or both.

15. The stent of any one of claims 1-13, wherein the elongated body comprises at least a partial covering.

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