Anti-migration stent

Abstract

The stent includes an expandable tubular body formed from one or more woven wires, and includes a plurality of anti-migration mechanisms each having a first end fixed to the tubular body and a second end extending radially outward from the outer surface of the tubular body. The anti-migration mechanism can be formed from a closed loop of one or more woven wires extending from the outer surface of the tubular body. The closed loop can be formed at the first end of the tubular body, at the second end of the tubular body, and / or along an intermediate region. In some cases, the base of the loop can be present at the intersection of the wires forming the closed loop. The wires can be welded at the intersection.

Description

Technical Field

[0001] The present disclosure relates to medical devices, and more particularly to an implantable stent having an anti-migration mechanism and a method for using such a medical device.

Background Art

[0002] For example, a wide variety of medical devices for medical use have been developed, including medical devices utilized in the treatment of body lumens. One type of endoluminal prosthesis used for the repair and / or treatment of diseases in various body lumens is a stent. A stent is a generally elongate tubular device formed of a biocompatible material useful for opening and supporting various lumens within the body. Stents can be used in various lumens within the body, such as the vascular system, bile ducts, urogenital tract, gastrointestinal tract, esophagus, trachea / bronchi, and bile ducts, as well as various other lumens within the body. Each of the known medical devices and methods has certain advantages and disadvantages. There is a continuing need to provide alternative medical devices, as well as alternative methods for manufacturing and using medical devices.

Summary of the Invention

[0003] The present disclosure provides alternatives in the design, materials, manufacturing methods, and use of medical devices. An exemplary stent is a tubular body formed from woven wires, the tubular body having a first open end, an opposite second open end, and a central longitudinal axis extending between the first open end and the second open end, the tubular body being movable between a radially compressed state and a radially expanded state, the tubular body, and a plurality of anti-migration mechanisms, each having a first end disposed on an outer surface of the tubular body and a second end extending radially outward from the outer surface of the tubular body, each of the plurality of anti-migration mechanisms being formed by one or more closed loops of woven wires, the base of the closed loop being located on the outer surface of the tubular body.

[0004] Alternatively or additionally to the above-described embodiments, the closed-loop base includes intersections of one or more woven wires forming the closed loop. Alternatively or additionally to any one of the above-described embodiments, one or more woven wires are welded at the intersections.

[0005] Alternatively or additionally to any one of the above-described embodiments, any tensile or compressive force applied to any of the plurality of anti-movement mechanisms does not reduce the outer diameter of the tubular body, or cause the tubular body to be axially extended or shortened.

[0006] Alternatively or additionally to any one of the above-described embodiments, the first portion of the plurality of anti-movement mechanisms is coupled to the tubular body adjacent to the first open end and extends at an acute angle towards the second open end with respect to the outer surface of the tubular body.

[0007] Alternatively or additionally to any one of the above-described embodiments, the second portion of the plurality of anti-movement mechanisms is coupled to the tubular body adjacent to the second open end and extends at an acute angle towards the first open end.

[0008] Alternatively or additionally to any one of the above-described embodiments, the first portion of the plurality of anti-movement mechanisms is coupled to the intermediate region of the tubular body and extends at an acute angle towards the first open end, and the second portion of the plurality of anti-movement mechanisms is coupled to the intermediate region of the tubular body and extends at an acute angle towards the second open end.

[0009] Alternatively or additionally to any one of the above-described embodiments, the base of each anti-movement mechanism of the first portion and the base of each anti-movement mechanism of the second portion are circumferentially spaced apart at a single longitudinal position along the tubular body.

[0010] Alternatively or additionally to any one of the above embodiments, the closed loop forming a plurality of anti-movement mechanisms is disposed at the first open end portion and extends radially outward from the tubular body.

[0011] Alternatively or additionally to any one of the above embodiments, the stent further includes a plurality of elongated closed loops extending substantially parallel to the central longitudinal axis at the first open end portion.

[0012] Alternatively or additionally to any one of the above embodiments, the plurality of elongated closed loops are inserted between adjacent closed loops among the plurality of closed loops forming a plurality of anti-movement mechanisms.

[0013] Alternatively or additionally to any one of the above embodiments, each closed loop is formed by a plurality of woven wires, and the ends of the plurality of woven wires are welded to the periphery of the closed loop.

[0014] Alternatively or additionally to any one of the above embodiments, each closed loop is formed by a part of four woven wires that collectively form the periphery of the closed loop.

[0015] Alternatively or additionally to any one of the above embodiments, the base portion includes the intersection of the first and second wires of the plurality of woven wires forming the closed loop. Alternatively or additionally to any one of the above embodiments, the first and second wires are welded to each other at the intersection.

[0016] Another exemplary stent is a tubular body formed from woven wires, the tubular body having a first open end, an opposite second open end, and a central longitudinal axis extending between the first open end and the second open end, the tubular body being movable between a radially compressed state and a radially expanded state, the tubular body, and a plurality of anti-migration mechanisms, each having a first end welded to one or more intersections of one or more of the woven wires forming the tubular body and a second end extending radially outward from the outer surface of the tubular body.

[0017] Alternatively or additionally to the above embodiments, each of the plurality of anti-migration mechanisms is at least partially formed by one of the plurality of woven wires forming the tubular body.

[0018] Alternatively or additionally to any one of the above embodiments, each of the plurality of anti-migration mechanisms is formed in a closed loop by a plurality of woven wires, and the ends of the plurality of wires are welded to the periphery of the closed loop.

[0019] A further exemplary stent is a radially expandable tubular body formed from woven wires, the tubular body having a first open end, an opposite second open end, and a central longitudinal axis extending between the first open end and the second open end, the tubular body being movable between a radially compressed state and a radially expanded state, the tubular body, and a plurality of anti-migration mechanisms disposed at the first open end, each of the plurality of anti-migration mechanisms having a first end disposed on the outer surface of the tubular body and a second end extending radially outward from the outer surface of the tubular body, each of the plurality of anti-migration mechanisms being formed in a closed loop by a plurality of woven wires, and the ends of the plurality of wires being disposed at the periphery of the closed loop.

[0020] Alternatively or additionally to the above embodiments, the ends of the plurality of wires are welded to the periphery of the closed loop. The above summary of some embodiments, aspects, and / or examples is not intended to describe every embodiment or all aspects of the present disclosure. The drawings and the following detailed description illustrate these embodiments more specifically. BRIEF DESCRIPTION OF THE DRAWINGS

[0021]

Figure 1

Figure 1A

Figure 1B

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Figure 11B

[0022] This disclosure can be more fully understood by considering the following detailed description of various embodiments in connection with the accompanying drawings. Aspects of the present disclosure are capable of following various modified forms and alternative forms, but specific aspects thereof are shown by way of example in the drawings and are described in detail. However, it should be understood that the intention is not to limit the aspects of the present disclosure to the specific embodiments described. On the contrary, the intention is to encompass all modified forms, equivalents, and alternative forms within the spirit and scope of the present disclosure.

[0023] For the terms defined below, these definitions shall apply unless different definitions are given in the claims or elsewhere in this specification. In this specification, all numerical values are considered to be modified by the term "about" whether explicitly indicated or not. The term "about" in the context of a numerical value generally refers to a range of numerical values that a person of ordinary skill in the art would consider equivalent (e.g., having the same function or result) to the recited value. In many cases, the term "about" may include the numerical value rounded to the nearest significant digit. Other uses of the term "about" (e.g., in contexts other than numerical values) may be understood from the context of the specification and may be considered to have the usual conventional definitions consistent with the context of the specification unless otherwise specified.

[0024] The description of a numerical range by upper and lower limits includes all numerical values within that range, including the upper and lower limits (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0025] Although some appropriate dimensions, ranges, and / or values regarding various components, features, and / or specifications are disclosed, those skilled in the art will understand that, inspired by the present disclosure, the desired dimensions, ranges, and / or values may deviate from those explicitly disclosed.

[0026] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. The term "or" as used in this specification and the appended claims is generally used in the sense of "and / or" unless the context clearly dictates otherwise. It should be noted that for ease of understanding, certain features of the present disclosure may be described in the singular even if they are plural or repeated within the disclosed embodiments. Each example of a feature may, unless expressly stated to the contrary, include and / or be encompassed by a singular disclosure. For purposes of simplification and clarity, not all elements of the disclosure are necessarily shown in each figure or described in detail below. However, it will be understood that the following description may equally apply to any and / or all of the multiple components, unless expressly stated to the contrary. Further, for clarity, not all examples of some elements or functions may be shown in each figure.

[0027] Relative terms such as "proximal", "distal", "advancing", "retreating", and their variations can generally be determined by considering the position, direction, and / or movement of various elements relative to the user / operator / implant of the device. Here, "proximal" and "retreating" indicate or refer to being closer to or moving towards the user, and "distal" and "advancing" indicate or refer to being farther from or moving away from the user. In some cases, the terms "proximal" and "distal" may be arbitrarily assigned for ease of understanding of the present disclosure, and such examples will be readily apparent to those skilled in the art. Other relative terms such as "upstream", "downstream", "inflow", and "outflow" refer to the direction of fluid flow within a lumen such as a body lumen, blood vessel, or within a device.

[0028] The term "range" can be understood to mean the maximum measured value of a recited or specified dimension, except when the range or dimension follows the recitation "minimum" or is identified as "minimum", in which case it can be understood to mean the minimum measured value of the recited or specified dimension. For example, "outer shape range" can be understood to mean the maximum outer shape dimension, "radial range" can be understood to mean the maximum radial dimension, "longitudinal range" can be understood to mean the maximum longitudinal dimension, and so on. Each example of "range" may be different (e.g., axial, longitudinal, transverse, radial, circumferential, etc.) and will be apparent to those skilled in the art from the context of the individual usage. Usually, "range" can be considered the maximum possible dimension measured according to the intended usage, and "minimum range" can be considered the minimum possible dimension measured according to the intended usage. In some cases, "range" may typically be measured at right angles within a plane and / or cross-section, but as is apparent from the particular context, it may be measured in different ways, for example, but not limited to, angular, radial, circumferential (e.g., along an arc), etc. Further, the term "substantially" as used in connection with two dimensions being "substantially the same" shall generally refer to a difference of 5% or less.

[0029] The terms "monolithic" and "single-piece" shall generally refer to an element that is composed of or consists of a single structure or basic unit / element. Monolithic and / or single-piece elements shall not include structures and / or features made by assembling or joining a plurality of individual elements.

[0030] References to "one embodiment", "some embodiments", "other embodiments", etc. in this specification indicate that the described embodiments may include certain features, structures, or characteristics, but it should be noted that not all embodiments necessarily include those specific features, structures, or characteristics. Further, such expressions do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in relation to an embodiment, unless explicitly stated otherwise or there is an express contrary statement, it is within the knowledge of those skilled in the art to make that particular feature, structure, or characteristic effective for other embodiments as well. That is, the various individual elements described below can be combined or arranged with each other to form other additional embodiments or to complement and / or enrich the described embodiments, as would be understood by those skilled in the art, even if not explicitly shown in a particular combination.

[0031] For the purpose of clarification, throughout this specification and / or the entire scope of the claims, a specific numerical nomenclature for identification (e.g., first, second, third, fourth, etc.) may be used to name and / or distinguish the various features described and / or claimed. It should be understood that the numerical nomenclature is not intended to be limiting and is merely illustrative. In some embodiments, for the sake of brevity and clarity, changes and departures from the previously used numerical nomenclature may occur. That is, a feature identified as the "first" element may later be referred to as the "second" element, the "third" element, etc., or may be completely omitted, and / or different features may be referred to as the "first" element. The meaning and / or name in each example will be apparent to those skilled in the art.

[0032] The following description should be read with reference to the drawings which are not necessarily to scale, and like reference numerals in different drawings designate like components. The detailed description and the drawings are intended to illustrate rather than to limit the disclosure. Those skilled in the art will recognize that the various components described and / or illustrated can be arranged in various combinations and configurations without departing from the scope of the disclosure. The detailed description and the drawings show exemplary embodiments of the disclosure. However, for clarity and ease of understanding, not all features and / or components may be shown in each drawing, and features and / or components may be understood to exist independently, unless otherwise specified.

[0033] Movement of the stent can occur with self-expanding stents such as fully covered stents. Current self-expanding stents, as exemplified by those used in endoscopic applications, can have mechanisms that facilitate prevention of movement, such as flared or tapered regions. These mechanical variations have met with varying degrees of success in reducing stent movement.

[0034] Figure 1 shows an expandable stent 100 having a plurality of anti - migration mechanisms 150. The stent 100 includes an expandable tubular body 120. The expandable tubular body 120 has a first open end 122, an opposite second open end 124, and a central longitudinal axis X - X extending between the first open end 122 and the second open end 124. The wall of the expandable stent 100 may define a lumen extending through the stent 100 along the central longitudinal axis X - X from the first open end 122 to the second open end 124. In some cases, the stent 100 may have a length, for example, from 30 mm to 200 mm, and an outer diameter of about 4 mm to about 28 mm. These dimensions are merely illustrative. Other lengths and / or diameters are contemplated. The tubular body 120 may be expandable from a radially compressed delivery state to a radially expanded deployed state, as shown in Figure 1. As is known in the art, the stent 100 may self - expand from a compressed delivery state to an expanded deployed state or may be expanded from a compressed delivery state to an expanded deployed state by a balloon or other expansion device. The tubular body 120 may be formed by a stent wall having an inner surface and an outer surface.

[0035] The stent 100 described herein may have a tubular body 120 having a substantially constant diameter from the first open end 122 to the second open end 124, as shown in Figure 1, or the stent 100 may have one end region or both end regions having a diameter larger than an intermediate region, as shown in Figure 2. Such a stent is considered to have a first flared end region and / or a second flared end region, as required.

[0036] The stent 100 can be formed from one or more, or a plurality of, woven wires 140 that form the tubular body 120 of the stent 100. The woven wire(s) 140 can be knitted, braided, twisted, looped, or otherwise woven along the length of the tubular body 120. The tubular body 120 can include a series of closed loops at one or both of the first and second open ends 122, 124 on both sides, as shown in FIG. 1. As used herein, the term "closed loop" is intended to refer to a loop having an enclosed perimeter where the entire perimeter of the loop is formed by one or more wires 140. In some embodiments, one or both of the open ends 122, 124 can include elongated closed loops 160. As shown in FIG. 1, the closed loop at the first open end 122 is an elongated closed loop 160, and the closed loop 161 at the second open end 124 is similar in size to the cells formed by the wires 140 woven or braided along the tubular body 120. In some cases, the ends of each of the plurality of woven wires 140 can all be disposed at the first open end 122 such that the plurality of ends of the plurality of woven wires 140 form a plurality of closed loops 160 at the first open end 122, while the bent portions along the intermediate region of the woven wires 140 can form a closed loop 161 at the second open end 124. In other embodiments, if necessary, some of the ends of the plurality of woven wires 140 can be disposed at the second open end 124, while the other ends of the plurality of woven wires 140 can be disposed at the first open end 122. In other embodiments, the tubular body 120 can be in the form of a mesh, a laser cut from a tube, or a laser cut from a sheet material welded to form a tube.

[0037] The stent 100 may include a plurality of anti - migration mechanisms 150 that extend radially outward from the outer surface of the tubular body 120. In some embodiments, one or more elongated closed loops 160 formed at one or both of the first open end 122 and the second open end 124 may form the anti - migration mechanism 150. The anti - migration mechanism 150 may be formed by one or more, or a plurality of, woven wires 140 that form the tubular body 120. In this embodiment, the anti - migration mechanism 150 may be formed of the same wires woven to form the body of the stent 100. In other embodiments, the anti - migration mechanism 150 may be formed separately and then fixed to the tubular body 120, for example, at the wire intersection 126. In such cases, the anti - migration mechanism 150 may be attached to the tubular body 120, for example, by welding or adhesively bonding the base of the anti - migration mechanism to the woven wires forming the body of the stent 100.

[0038] As shown in FIGS. 1A, 1B, and 1C, the elongated closed loop 160 at the first open end 122 is bent outwardly to form an anti-movement mechanism 150. Each of the plurality of anti-movement mechanisms 150 or the plurality of closed loops 160 may have a first end 152 located on the wall of the tubular body 120 or otherwise coupled to the tubular body 120, and a second end 154 extending radially outward from the outer surface of the tubular body 120 to the apex of the anti-movement loop 160. As described herein, the direction in which the anti-movement loop 160 extends is from the first proximal end 152 located on the tubular body 120 to the second free end 154 of the anti-movement loop 160. The anti-movement mechanism 150 (e.g., the anti-movement loop 160) may have a length from the first end 152 to the second end 154. In some embodiments, at least some of the plurality of anti-movement mechanisms 150 may have a length of at least one-third of the outer diameter of the tubular body 120 as measured at the widest point of the tubular body 120. In other embodiments, the length of the anti-movement mechanism 150 may be at least half of the outer diameter of the tubular body 120. In some cases, the first end 152, i.e., the base, of each anti-movement mechanism 150 (e.g., the anti-movement loop 160) is fixed to or fixedly attached to the tubular body 120 such that any tensile or compressive force applied in any direction to the anti-movement mechanism 150 (e.g., the anti-movement loop 160) does not increase or decrease the size of the anti-movement mechanism 150 (e.g., the anti-movement loop 160), does not decrease or expand the outer diameter of the tubular body 120, or does not stretch or shorten the tubular body 120. Thus, in some cases, the size of each anti-movement mechanism 150 may be fixed. In some cases, the base of the closed loop 160, i.e., the first end 152, is formed by the first wire 51 crossing over / under the second wire 52 when the wires 51 / 52 extend from the tubular body 120 and begin to form the closed loop 160.In other words, in an embodiment where the anti - movement mechanism 150 is formed from a plurality of wires 140 that form the woven tubular body 120, the first end 152 can be defined by an intersection 126 where two wires 140 extend from the woven tubular body 120 and cross each other when the wires 140 form the anti - movement mechanism 150. Thus, the intersection 126 of the first and second wires 51 / 52 can form part of the surrounded perimeter of the closed loop 160. In some cases, the first end 152, i.e., the base, of each anti - movement closed loop 160 of the plurality of anti - movement loops 160 can be arranged in a single circumferential row of intersections 126 at the first end 122 of the stent 100. In other words, the plurality of intersections of the plurality of anti - movement loops 160 at the end of the stent can be circumferentially arranged around the tubular body 120 at a single longitudinal position.

[0039] An enlarged view of the end region of the stent 100 of FIG. 1 is shown in FIG. 1A. As shown in FIG. 1A, each closed loop 160 forming the anti-migration mechanism 150 can be formed from a plurality of wires 140 that extend from the woven tubular body 120 and are fixed (e.g., welded) to each other. For example, a first wire 51 that extends in a first helical direction along the woven tubular body 120 can extend from the woven tubular body 120 and be bent to form the apex 64 of the loop 160 at the free end 154 of the loop 160. A second wire 52 that extends in a second helical direction opposite to the first helical direction along the woven tubular body 120 intersects the first wire 52 at the proximal end 152 of the loop 160 and can have a terminus joined to the terminus of the first wire 51 along the outer periphery of the loop 160 at a first fixed position 61. A third wire 53 that can extend in a first helical direction parallel to the first wire 51 along the woven tubular body 120 can have a terminus joined to the terminus of the first wire 51 and / or the second wire 52 at the first fixed position 61. A fourth wire 54 that can extend in a second helical direction parallel to the second wire 52 along the woven tubular body 120 can have a terminus joined to the first wire 51 at a second fixed position 62. The first and second fixed positions can be welding positions in some cases. For example, the termini of the first, second, and third wires can be welded together at the first fixed position 61, and the terminus of the fourth wire 54 can be welded to the first wire 51 at the second fixed position 62. The first and second fixed positions can be, for example, on both sides of the loop 160. Thus, the periphery of each loop 160 can be formed from a portion of four individual wires 140 of the tubular body 120. Thus, in some cases, the stent 100 can include a number of wires forming the tubular body 120 that is four times the number of loops 160 at the first end of the stent 100. In the embodiment of FIG. 1A, the first wire 51 can intersect the second wire 52, but is not fixed to the second wire 52 at the intersection 126 at the base 152 of the loop 160.In another embodiment, as shown in FIG. 1B, the first wire 51 intersects the second wire 52 at the intersection 126 of the base 152 of the loop 160 and can be welded together at the intersection 126. When the wires 51 / 52 are welded together at the intersection 126, the deflection of the anti - movement mechanism 150 cannot decrease or increase the diameter or length of the tubular body 120, and thus cannot function as a retrieval element.

[0040] The second end 154 of the closed loop 160 can be a free end forming the apex 64 of the closed loop 160. At least some of the second ends 154 of the anti - movement mechanism 150 can extend radially outward beyond the outermost extent of the outer surface of the tubular body 120. In some cases, the first end 152 of the anti - movement mechanism 150 can include a single attachment point to the tubular body 120, while in other cases, the first end 152 of the anti - movement mechanism 150 can include multiple attachment points to the tubular body 120. For example, the anti - movement mechanism 150 can be formed by one wire 140 or a plurality of wires 140 that exit and re - enter the tubular body 120 at different spaced positions such that the first end 152 of the anti - movement mechanism 150 is formed by a plurality of wire intersections 126 and / or a plurality of welding positions. In some embodiments, the first end 152 of the anti - movement mechanism 150 coupled to the tubular body 120 can be defined at a single wire intersection 126 where two wires (e.g., the first wire 51 and the second wire 52) intersect as they extend from the tubular body 120, as shown in FIGS. 1A and 1B. In some cases, the weld 153 can fix the first end 152 so as to oppose the expansion of the anti - movement mechanism 150 at the intersection 126, as shown in FIG. 1B. Regardless of the number of wire intersections 126 involved in forming the anti - movement mechanism 150, the wire intersections 126 can be welded such that any tensile or compressive force applied to the anti - movement mechanism 150 does not cause the diameter of the tubular body 120 to change or the tubular body 120 to be stretched / shortened. In such cases, the anti - movement mechanism 150 does not function as a retrieval element for compressing and / or stretching the stent 100 for removal.

[0041] In another embodiment shown in FIG. 1C, the first end portion 122 of the stent 100 may include a plurality of large closed loops 160 that form an anti - migration mechanism 150, and a plurality of small closed loops 165 are interposed between adjacent large closed loops 160. Each closed loop 160 forming the anti - migration mechanism 150, as well as each small closed loop 165, may extend from the woven tubular body 120 and be formed from a plurality of wires 140 that are woven together and fixed to each other. For example, a first wire 51 extending in a first helical direction along the woven tubular body 120 may extend from the woven tubular body 120 and be bent to form the apex 64 of the large closed loop 160 at the free end 154 of the closed loop 160. A second wire 52 extending in a second helical direction opposite to the first helical direction along the woven tubular body 120 may intersect the first wire 52 at the base end 152 of the loop 160 and may have an end joined to the end of the first wire 51 along the outer periphery of the loop 160 at a first fixed position 61. A third wire 53 that may extend in a first helical direction parallel to the first wire 51 along the woven tubular body 120 may be bent to form the apex of the small closed loop 165. A fourth wire 54 that may extend in a second helical direction parallel to the second wire 52 along the woven tubular body 120 may have an end joined to the third wire 53 at a second fixed position 63. In some cases, the large loops 160 are alternately arranged with the small loops 165 along the circumference of the end portion 122 of the tubular body 120 of the stent 100. In some cases, the small closed loops 165 may be juxtaposed with the large closed loops 160 such that the outer periphery of the small closed loops 165 is not fixed to the outer periphery of the large closed loops 160. In other words, the periphery of the large loop 160 may be free from fixation (e.g., welding) to the periphery of the small loop 165, and as a result, the large loop 160 may be able to flex freely with respect to the small loop 165. The large closed loop 160 may be bent radially outward with respect to the small loop 165.For example, the small loop 165 may extend longitudinally substantially parallel to the wall of the tubular body 120, while the large loop 160 may extend radially outward at an oblique angle (i.e., an acute or obtuse angle) or a perpendicular angle with respect to the small loop 165.

[0042] The anti - movement mechanism 150 (some examples of which are shown in FIGS. 1A - 1C) may extend outward from the outer surface of the tubular body 120 at an angle θ (such as an oblique angle or a perpendicular angle) with respect to the central longitudinal axis and / or the outer surface of the tubular body 120. In some cases, as shown in FIG. 1, the angle may be an obtuse angle at which the anti - movement mechanism 150 extends towards the first open end 122. In other cases, the angle may be an acute angle at which the anti - movement mechanism 150 is bent back towards the second open end 124, if necessary. In still other examples, the angle may be a perpendicular angle. In some cases, the angle θ may be about 10° to about 160°, about 100° to about 160°, about 100° to about 140°, about 90° to about 120°, about 20° to about 90°, about 30° to about 80°, about 20° to about 45°, etc. At least some of the second ends 154 of the plurality of anti - movement mechanisms 150 extend radially outward beyond the outermost extent of the surface of the tubular body 120. The plurality of anti - movement mechanisms 150 may be deflected to a position with an enlarged angle with respect to the tubular body 120 when unrestrained and / or when the stent is deployed in an expanded configuration.

[0043] In some embodiments, the stent 100 may include a cover 70 (see FIG. 1) disposed to cover at least a portion of the tubular body 120 of the stent 100. For example, the cover 70 may completely cover the entire length of the tubular body 120 of the stent 100 to form a fully covered stent in which all of the mesh cells or closed cells defined in the woven pattern (e.g., braided pattern) of the tubular body 120 are covered by the cover 70, thereby preventing tissue ingrowth and / or fluid leakage into the lumen of the tubular body 120. In other examples, the cover 70 may cover only a portion of the length of the tubular body 20 of the stent 100 to form a partially covered stent in which some of the mesh cells or closed cells defined in the woven pattern (e.g., braided pattern) remain uncovered, allowing tissue ingrowth. In some cases, the anti-migration mechanism 150 may be covered by the cover 70, and thus the entire stent 100 including the entire tubular body 120 as well as the anti-migration mechanism 150 and the closed loop 60 may be covered by the cover 70. In some cases, the cover 70 may be formed by immersing the stent 100 in a solution of silicone or other polymer, or by spray coating the stent 100 with silicone or other polymer. In other examples, a polymer sheet or polymer tube may be disposed around and / or within the tubular body 120 to form the cover 70. The cover 70 may be disposed on the outer surface or the inner surface of the tubular body 120, or on both the inner and outer surfaces of the tubular body 120, whereby the tubular body 120 of the stent 100 is embedded within the polymeric material. The coating or cover may be a polymeric cover such as a polytetrafluoroethylene (PTFE) cover or a silicone cover, although other covers, particularly elastomeric polymers, may be used. Non-limiting examples of useful polymeric materials include polyester, polypropylene, polyethylene, polyurethane, polynaphthalene, polytetrafluoroethylene, expanded polytetrafluoroethylene, silicone, and combinations and copolymers thereof.

[0044] In another embodiment, a stent 200 similar to the stent 100 may have a plurality of anti - migration mechanisms 250 formed from a plurality of closed loops 260 that extend radially outward from the outer surface of the tubular body 220 at an angle of about 90 degrees, as shown in FIG. 2. The anti - migration mechanisms 250 may be configured as one or more, or a plurality of, closed loops formed from wires that are woven together to form the tubular body 200, similar to the anti - migration mechanisms 150 described above. The plurality of anti - migration mechanisms 250 may be deflected to a position with an enlarged angle with respect to the tubular body 220 when unrestrained and / or when the stent is deployed in an expanded configuration. The tubular body 220 may include a first outward flare region 227 at the first open end 222 and / or a second outward flare region 229 at the second open end 224. The first and / or second outward flare regions 227, 229 may have an outer diameter that is larger than the outer diameter of the remainder of the tubular body 220. The plurality of anti - migration mechanisms 250 may extend from the first and / or second outward flare regions 227, 229. In the side view shown in FIG. 2, only two anti - migration mechanisms 250 (e.g., closed loops) are visible, but it will be understood that additional anti - migration mechanisms 250 (e.g., closed loops) may extend around the first open end 222, similar to the arrangement shown in FIG. 1. In some cases, the first end 252, i.e., the base, of each anti - migration closed loop 260 of the plurality of anti - migration loops 260 may be arranged in a single circumferential row of intersections of the wires forming the tubular body 220 at the first end 222 of the stent 200. In other words, the plurality of intersections of the plurality of anti - migration loops 260 at the end of the stent may be circumferentially arranged around the tubular body 220 at a single longitudinal position.

[0045] Figure 3 shows a further embodiment of the stent 300 in which a plurality of anti - movement mechanisms 350 formed as a plurality of closed loops 360 are alternately arranged with elongated closed loops 368 extending parallel to the longitudinal axis of the tubular body 320. The plurality of closed loops 360 and the plurality of closed loops 368 can be formed in the same manner as the plurality of closed loops 160 described above. It will be understood that the anti - movement mechanisms 350 and the longitudinally elongated closed loops 368 can be in any arrangement, such as the second, third, fourth, or fifth loop being the anti - movement mechanism 350 and the remaining loops being the longitudinally elongated closed loops 368. In some cases, each anti - movement loop 360 can be circumferentially disposed between adjacent ones of the longitudinally elongated closed loops 368. Additionally, the anti - movement mechanisms 350 and the longitudinally elongated closed loops 368 can form an irregular pattern around the open end of the stent 300. The anti - movement mechanism 350 can extend from the first open end 322 at an angle (such as an oblique or perpendicular angle) with respect to the central longitudinal axis and / or the outer surface of the tubular body 320 of the stent 100. As shown in Figure 3, in some cases, the closed loops 360 forming the anti - movement mechanism 350 can extend towards the opposite end 324 of the stent 300 from the longitudinally elongated loops 368. In other examples, the closed loops 360 forming the anti - movement mechanism 350 can extend towards the same end 322 of the stent 300 as the longitudinally elongated loops 368. In some cases, the anti - movement mechanism 350 can extend at an angle of about 20 degrees to about 60 degrees with respect to the outer surface of the tubular body 320. In some cases, the angle θ can be about 10° to about 160°, about 100° to about 160°, about 100° to about 140°, about 90° to about 120°, about 20° to about 90°, about 30° to about 80°, about 20° to about 45°, etc. The plurality of anti - movement mechanisms 350 can be deflected to a position with an enlarged angle when unrestrained and / or when the stent is deployed in an expanded configuration.

[0046] In some cases, each anti - migration closed loop 360 at the first end 322 of the stent 300 and the first end 352, i.e., the base, of each longitudinally elongated loop 368 can be arranged in a single circumferential row of intersections of the wires forming the tubular body 320 at the first end 322 of the stent 300. In other words, the plurality of intersections of the plurality of anti - migration loops 360 and the longitudinally extending loops 368 at the end of the stent can be circumferentially arranged around the tubular body 320 at a single longitudinal position. The second free end 354 of the anti - migration loop 360 can extend in a first longitudinal direction from the circumferential row of the base end 322, while the second free end 354 of the longitudinally extending loop 368 can extend in a second opposite longitudinal direction from the circumferential row of the base end 322.

[0047] In the illustrated embodiment, the first open end 322 is substantially cylindrical, and the outer diameter is maintained constant from the first open end 322 to the second flare region 329 adjacent to the second open end 324. Alternatively, the entire tubular body 320 can be cylindrical with a constant outer diameter, similar to the stent 100 shown in FIG. 1A.

[0048] Figures 4-8 show stents 400, 500, 600, 700, 800 with anti-migration mechanisms 450, 550, 650, 750, 850 in various arrangements. The stent 400 shown in Figure 4 is coupled to the stent 400 adjacent to the first open end 422 and includes a first portion of an anti-migration mechanism 450 (formed as a closed loop 460) that extends at an acute angle with respect to the outer surface of the tubular body 420 toward the second open end 424 on the opposite side. The second portion of the anti-migration mechanism 450 (formed as a closed loop 460) is coupled to the tubular body 420 adjacent to the second open end 424 and extends at an acute angle with respect to the outer surface of the tubular body 420 toward the first open end 422. Each of the closed loops 460 can be formed from one or more wires that form the woven structure of the tubular body 420. In the illustrated embodiment, the first and second portions of the anti-migration mechanism 450 extend at an angle of about 20-30 degrees with respect to the central longitudinal axis or the outer surface of the tubular body 420 toward either the first or second open ends 422, 424. However, in other cases, the anti-migration mechanism 450 can extend at any desired angle, as described above. The plurality of anti-migration mechanisms 450 can be deflected to a position with an enlarged angle when unrestrained and / or when the stent is deployed in an expanded configuration. In some embodiments, the tubular body 420 can include one or more elongated closed loops 468 that extend from either or both of the first open end 422 and the second open end 424. These elongated closed loops 468 can extend parallel to the central longitudinal axis extending through the tubular body 420. In other embodiments, the elongated closed loops 468 extend at an angle with respect to the longitudinal axis that is different from the angle of the closed loops 460 and thus can form an additional anti-migration mechanism. As shown in Figure 4, the anti-migration closed loop 460 at the first end 422 of the stent 400 can extend toward the second end 424, while the longitudinally elongated closed loop 468 at the first end 422 extends toward the first end 422 and thus extends in a direction substantially opposite to the anti-migration closed loop 460 at the first end 422.In addition, the anti - movement closed loop 460 at the second end 424 of the stent 400 may extend towards the first end 422, while the longitudinally elongated closed loop 468 at the second end 424 extends towards the second end 424 and thus extends in a direction substantially opposite to that of the anti - movement closed loop 460 at the second end 424.

[0049] In some cases, the first end 452, i.e., the base, of each anti - movement closed loop 460 and each longitudinally elongated loop 468 at the first end 422 and / or the second end 424 of the stent 400 may be arranged in a single circumferential row of intersections of the wires forming the tubular body 420 at the first end 422 of the stent 400 or at the second end 424 of the stent 400, respectively. In other words, the plurality of intersections of the plurality of anti - movement loops 460 and the longitudinally extending loops 468 at the end of the stent may be circumferentially arranged around the tubular body 420 at a single longitudinal position. The second free end 454 of the anti - movement loop 460 may extend in a first longitudinal direction from the circumferential row of the base end 422, while the second free end 454 of the longitudinally extending loop 468 may extend in a second opposite longitudinal direction from the circumferential row of the base end 422.

[0050] The stent 500 shown in FIG. 5 includes a first open end 522, a second open end 524, and a plurality of anti - migration mechanisms 550 extending at various angles at both open ends. In some cases, the first end 522 and / or the second end 524 can be flare ends having an outer diameter larger than the outer diameter of the intermediate region of the tubular body 520. As shown in FIG. 5, the first portion of the anti - migration mechanism adjacent to the first open end 522 can include an anti - migration mechanism 550a (e.g., a closed loop 560) extending in a first longitudinal direction from the base 552 of the closed loop 560, and an anti - migration mechanism 550b (e.g., a closed loop 560) extending in a second opposite longitudinal direction from the base 552 of the closed loop 560. In some cases, the anti - migration mechanism 550a extending away from the intermediate region of the stent 500 can extend at an angle greater than 90 degrees (e.g., 100 degrees to 130 degrees) with respect to the outer surface of the tubular body 520, and the anti - migration mechanism 550b extending toward the intermediate region of the stent 500 can extend at an angle less than 90 degrees (e.g., 20 degrees to 85 degrees) with respect to the outer surface of the tubular body 520. The plurality of anti - migration mechanisms 550 (i.e., closed loops 560) can be formed in the same manner as the other anti - migration mechanisms described herein. The plurality of anti - migration mechanisms 550 can be deflected to an expanded - angle position when unrestrained and / or when the stent is deployed in an expanded configuration.

[0051] In some cases, the first end 552, i.e., the base, of each anti - migration closed loop 560 and each longitudinally - elongated loop 568 at the first end 522 and / or the second end 524 of the stent 500 can be arranged in a single circumferential row of intersections of the wires forming the tubular body 520 at the first end 522 or the second end 524 of the stent 500, respectively. In other words, the plurality of intersections of the plurality of anti - migration loops 560 and the longitudinally - extending loops 568 at the end of the stent can be circumferentially arranged around the tubular body 520 at a single longitudinal position. The second free end 554 of the anti - migration loop 560 can extend in a first longitudinal direction from the circumferential row of the base end 522, while the second free end 554 of the longitudinally - extending loop 568 can extend in a second opposite longitudinal direction from the circumferential row of the base end 522.

[0052] The stent 600 shown in FIG. 6 includes a first flared end 627 adjacent to the first open end 622 and a second flared end 629 adjacent to the second open end 624. A plurality of elongated loops forming vertices at the first open end 622 extend substantially parallel to the longitudinal axis of the tubular body 620 at the first open end 622. The stent 600 further includes a plurality of anti - migration mechanisms 650 in an intermediate region of the tubular body 620. The plurality of anti - migration mechanisms 650 can be formed as a plurality of closed loops 660, similar to other anti - migration mechanisms described herein. The anti - migration mechanism 650 can include a first portion 650a of the anti - migration mechanism extending toward the first open end 622 and a second portion 650b of the anti - migration mechanism extending toward the second open end 624. As shown, the first and second portions of the anti - migration mechanisms 650a, 650b are alternately arranged on the circumference of the tubular body 620. Each of the anti - migration mechanisms 650a, 650b can extend at an acute angle (such as 10 degrees to 80 degrees) with respect to the outer surface of the tubular body 620. In some embodiments, the anti - migration mechanisms 650a, 650b can extend at different angles. The plurality of anti - migration mechanisms 650a, 650b can be deflected to a position with an enlarged angle when unrestrained and / or when the stent is deployed in an expanded configuration.

[0053] In some cases, the first end 652, i.e., the base, of each anti - migration mechanism 650a (e.g., closed loop 660) extending toward the first end 622 and each anti - migration mechanism 650b (e.g., closed loop 660) extending toward the second end 624 can be arranged in a single circumferential row of intersections of the wires forming the tubular body 620. In other words, the intersections of the plurality of anti - migration loops 660 extending in both longitudinal directions can be circumferentially arranged around the tubular body 620 at a single longitudinal position. The second free end 654 of the anti - migration mechanism 650a can extend in a first longitudinal direction from the circumferential row of the base end 622 toward the first end 622, and the second free end 654 of the anti - migration mechanism 650b can extend in a second opposite longitudinal direction from the circumferential row of the base end 622 toward the second end 624.

[0054] The anti-movement mechanisms 650a, 650b can be formed by loops extending radially in the wire forming the tubular body 620, and the loops extend radially outward from the outer surface of the tubular body 620. The wire loops can be closed loops that cross the wire itself at the base of the loop disposed on the tubular body 620 before the wire enters the woven structure forming the tubular body 620. In some cases, the base of the loop (e.g., the intersection) can be welded so that the size of the loops forming the anti-movement mechanisms 650a, 650b does not expand or contract. In other embodiments, the anti-movement mechanisms 650a, 650b are formed by separately formed wire loops and can be attached to the tubular body 620 at the intersection, such as by welding, so that the tensile or compressive force on the loops does not reduce the outer diameter of the tubular body 620 or change its length. In some cases, the wire forming the wire loop may not cross the wire itself at the base of the wire loop; rather, two portions of the wire can enter the woven structure forming the tubular body 620 at spaced positions. In some cases, the portions of the two wires can be welded to another wire forming the tubular body 620 at spaced positions where the portions of the two wires enter the woven structure forming the tubular body 620.

[0055] The stent 700 shown in FIG. 7 has a combination of the features of the stents 500 and 600 shown in FIGS. 5 and 6, and includes a first portion of the anti - movement mechanism 750 adjacent to the first open end 722, a second portion of the anti - movement mechanism 750 adjacent to the second open end 724, and a third portion of the anti - movement mechanism 750 in the intermediate region of the stent 700. The above description is applicable to the embodiment of FIG. 7. The plurality of anti - movement mechanisms can be formed from a plurality of closed loops 760, similar to the other closed - loop configurations described herein. The closed loop 760 in the intermediate region can include a first portion 750a of the anti - movement mechanism extending in a first longitudinal direction and a second portion 750b of the anti - movement mechanism extending in a second opposite longitudinal direction. Similarly, the closed loop 760 at the first open end 722 can include a first portion extending in a first longitudinal direction and a second portion extending in a second opposite longitudinal direction, and / or the closed loop 760 at the second open end 724 can include a first portion extending in a first longitudinal direction and a second portion extending in a second opposite longitudinal direction. In each of the first, second, and third portions, the anti - movement mechanism 750 can extend at any desired oblique angle (e.g., acute or obtuse angle) or a perpendicular angle with respect to the central longitudinal axis or the outer surface of the stent 700. For example, in some cases, the closed loop 760 can extend at an angle of 20 degrees to 120 degrees with respect to the outer surface of the stent towards either the first open end 722 or the second open end 724. The plurality of anti - movement mechanisms 750 can be deflected to a position with an enlarged angle when unrestrained and / or when the stent is deployed in an expanded configuration. In some cases, the first and second portions of the anti - movement mechanism can be disposed on the first flare end region at the first end 722 and the second flare end region at the second end 724, respectively. Each of the plurality of anti - movement mechanisms 750 can extend at the same angle or different angles.

[0056] FIG. 8 shows a stent 800 having a first open end 822 with a first flare end region 827 and a second open end 824 with a second flare end region 829, and there is no anti - migration mechanism at each end. The first open end 822 and / or the second open end 824 may include one or more elongated loops that form a vertex at the first open end 822 extending substantially parallel to the longitudinal axis of the stent 800. The stent 800 further includes a plurality of anti - migration mechanisms 850 that may be disposed in an intermediate region of the tubular body 820 between the first open end 822 and the second open end 824. The plurality of anti - migration mechanisms 850 may be formed as a plurality of closed loops 860, similar to other anti - migration mechanisms described herein. The anti - migration mechanisms 850 may exist in a plurality of separate sets spaced longitudinally from each other, and each set includes a first portion of the anti - migration mechanism 850 (e.g., closed loop 860) extending toward the first open end 822 and a second portion of the anti - migration mechanism 850 (e.g., closed loop 860) extending toward the second open end 824. The anti - migration mechanisms 850 may alternate directions as shown in FIG. 8. The anti - migration mechanisms 850 may extend at any oblique angle (e.g., acute or obtuse angle) or a perpendicular angle (e.g., at an angle between 20 degrees and 120 degrees with respect to the outer surface of the stent) with respect to the central longitudinal axis or the outer surface of the stent 800 toward either the first open end 822 or the second open end 824. Each of the plurality of anti - migration mechanisms 850 may extend at the same angle or different angles. The plurality of anti - migration mechanisms 850 may be deflected to a position with an expanded angle when unrestrained and / or when the stent is deployed in an expanded configuration.

[0057] In some cases, with respect to the first set of anti - movement mechanisms 850 at a first position along the intermediate region of the stent 800, each anti - movement mechanism 850 (e.g., closed loop 860) extending toward the first end 822 and the first end 852, i.e., the base, of each anti - movement mechanism 850 (e.g., closed loop 860) extending toward the second end 824 can be arranged in a single circumferential row of intersections of the wires forming the tubular body 820. In other words, the intersections of the plurality of anti - movement loops 860 extending in both longitudinal directions can be circumferentially arranged around the tubular body 820 at the first longitudinal position. The second free end 854 of the first portion of the anti - movement mechanism 850 can extend in a first longitudinal direction from the circumferential row of the base end 822 toward the first end 822, and the second free end 854 of the second portion of the anti - movement mechanism 850 can extend in a second opposite longitudinal direction from the circumferential row of the base end 822 toward the second end 824.

[0058] The stent 800 can include a second set of anti - movement mechanisms 850 arranged at a second position along the intermediate region of the stent 800 longitudinally spaced from the first set of anti - movement mechanisms 850. With respect to the second set of anti - movement mechanisms at a second position along the intermediate region of the stent 800, each anti - movement mechanism 850 (e.g., closed loop 860) extending toward the first end 822 and the first end 852, i.e., the base, of each anti - movement mechanism 850 (e.g., closed loop 860) extending toward the second end 824 can be arranged in a single circumferential row of intersections of the wires forming the tubular body 820. In other words, the intersections of the plurality of anti - movement loops 860 extending in both longitudinal directions can be circumferentially arranged around the tubular body 820 at the first longitudinal position. The second free end 854 of the first portion of the anti - movement mechanism 850 can extend in a first longitudinal direction from the circumferential row of the base end 822 toward the first end 822, and the second free end 854 of the second portion of the anti - movement mechanism 850 can extend in a second opposite longitudinal direction from the circumferential row of the base end 822 toward the second end 824.

[0059] Figures 9A and 9B illustrate a portion of the stent 900 in which a plurality of anti - migration mechanisms 950 extend from a first open end 922 of the tubular body 920 of the stent 900. Each of the anti - migration mechanisms 950 can be formed by a loop - shaped portion of a wire 940 that extends between two intersections 926 as the wire 940 extends outwardly from the tubular body 920 of the stent 900. Thus, the plurality of anti - migration mechanisms 950 can be formed by the wire 940 that extends between two circumferentially spaced intersections 926, as shown in FIG. 9A. The wire 940 is welded at the two intersections 926 to another wire forming the braided structure of the tubular body 920 to prevent any tensile or compressive force applied to the anti - migration mechanism 950 from reducing the outer diameter of the stent 900 or stretching the stent 900. The anti - migration mechanisms 950 can extend radially outward from the outer surface of the tubular body 920 at any desired angle, such as an oblique angle (e.g., an acute or obtuse angle) or a perpendicular angle, with respect to the central longitudinal axis and / or the outer surface of the tubular body 920. In some cases, the angle can be an obtuse angle at which the anti - migration mechanism 950 extends toward the first open end 922. In other cases, the angle can be an acute angle at which the anti - migration mechanism 950 is bent back, as needed, toward a second open end on the opposite side of the stent 900 (not shown). In yet other examples, the angle can be a perpendicular angle. In some cases, the angle can be about 10 degrees to about 160 degrees, about 100 degrees to about 160 degrees, about 100 degrees to about 140 degrees, about 90 degrees to about 120 degrees, about 20 degrees to about 90 degrees, about 30 degrees to about 80 degrees, about 20 degrees to about 45 degrees, etc. The plurality of anti - migration mechanisms 950 can form a petal structure when viewed from the end, as shown in FIG. 9B. The plurality of anti - migration mechanisms 950 can be deflected to a position with an enlarged angle with respect to the tubular body 920 when unrestrained and / or when the stent is deployed in an expanded configuration. The stent 900 can optionally include a first flare region 927 adjacent to the first open end 922. As shown in FIG. 9B, the first open end 922 is disposed around the circumference of the tubular body 920 and can include a plurality of anti - migration mechanisms 950 that extend radially outward from the circumference of the tubular body 920.

[0060] FIG. 10 illustrates a stent 1000 having an alternative anti - migration structure. In this embodiment, all of the plurality of closed loops 1060 at the first open end portion 1022 of the stent 1000 are largely enlarged closed loops 1060 that form an anti - migration mechanism 1050. In some cases, the enlarged closed loop 1060 can be formed from a loop - shaped portion of a single wire where the wire itself crosses at an intersection at the base of the closed loop 1060. In some embodiments, each of the plurality of enlarged closed loops 1060 can have an outermost diameter that is at least 2 times, at least 3 times, or at least 4 times the outer diameter of the tubular body 1020 of the stent 1000. In some cases, the enlarged closed loop 1060 can have a length that is at least one - half or more of the outer diameter of the tubular body 1020 forming the stent 1000, or a length that is equal to or greater than the outer diameter of the tubular body 1020 of the stent 1000. The enlarged closed loop 1060 can be a polygon such as an ellipse or an octagon. The enlarged closed loop 1060 can extend from the first open end portion 1022 at any desired angle with respect to the central longitudinal axis and / or the outer wall of the tubular body 1020. The plurality of anti - migration mechanisms 1050 can be deflected to a position with an enlarged angle when unrestrained and / or when the stent is deployed in an expanded configuration.

[0061] A further embodiment of the stent 1100 may have a plurality of enlarged closed loops 1160 extending from both the first open end 1122 and the second open end 1124, as shown in FIG. 11A. The enlarged closed loops 1160 may extend radially outward at any desired angle, such as an angle of about 45 degrees to about 90 degrees from the longitudinal axis X-X extending through the stent 1100 from the tubular body 1120 forming the stent 1100. In some embodiments, each end of the enlarged closed loop 1160 may extend from the intersection 1126. The enlarged closed loop 1160 may be formed from the wire 1140 forming the tubular body 1120. In other embodiments, the enlarged closed loop 1160 may be formed separately and fixed to the tubular body 1120. Whether the enlarged closed loop 1160 is formed from the wire 1140 forming the tubular body 1120 or is formed separately and fixed to the tubular body 1120, the intersection 1126 where the enlarged closed loop extends may be welded. This prevents any tensile or compressive force applied to the enlarged closed loop 1160 from reducing the diameter of the tubular body 1120 or stretching the tubular body 1120. Thus, the enlarged closed loop 1160 does not form a retrieval or removal structure. The enlarged closed loop 1160 may be deflected to an enlarged angular position when unrestrained and / or when the stent is deployed in an expanded configuration.

[0062] The stent 1100 can be used as a conduit to establish fluid communication between adjacent body lumens. For example, the stent 1100 can be used as a drainage stent, a fistula, an anastomosis, etc. The enlarged closed loop 1160 can be configured to engage two adjacent body lumens 1105, 1107 and hold them in place so that fluid can flow between the adjacent body lumens 1105, 1107, as shown in FIGS. 11A and 11B. In one example, the stent 1100 can be used to drain bile and / or gallstones from the gallbladder to the duodenum. In another example, the stent 1100 can be used in endoscopic procedures such as gastrojejunostomy, and the stent 1100 can be used to form an anastomosis between the stomach 1105 and the small intestine 1107 to form a bypass of the duodenum. Details of the surgical procedure are described in U.S. Patent Application Publication No. 2019 / 0298401, which is incorporated herein by reference in its entirety.

[0063] In all of the above embodiments, the anti - movement mechanisms 150, 250, 350, 450, 550, 650, 750, 750, 950, 1050, 1150 can be formed by a single wire whose both ends are fixed to the tubular body to form a closed loop. The closed - loop anti - movement mechanism can be fixed to the tubular body such that any tensile or compressive force applied to the anti - movement mechanism does not result in a reduced diameter of the tubular body or elongation or shortening of the tubular body. Thus, the anti - movement mechanism is not intended to function as a retrieval element. Alternatively, the anti - movement mechanism can be formed by a part of a plurality of wires extending from the woven structure of the tubular body of the stent. In some cases, the ends of the plurality of wires are welded or otherwise fixed together to form a closed loop, and the proximal end of the closed loop is fixed to the tubular body. The proximal end of each closed loop can be arranged at a single intersection within the tubular body, or the proximal end of each loop can be fixed to an adjacent intersection. In all of the above - described embodiments, the anti - movement mechanisms 150, 250, 350, 450, 550, 650, 750, 750, 950, 1050, 1150 can be movable between a delivery configuration in which the anti - movement mechanism extends substantially parallel to the central longitudinal axis of the tubular body of the stent and a deployment configuration in which the anti - movement mechanism extends radially away from the central longitudinal axis. The anti - movement mechanism is biased towards the deployment configuration when unrestrained and / or when the stent is deployed in the expanded configuration. The anti - movement mechanism can be held in the delivery configuration by an outer sheath disposed over the stent. By releasing the stent from the outer sheath, it becomes possible for the anti - movement mechanism to expand into an angled configuration. In other embodiments, a suture or wire can be passed through a plurality of anti - movement mechanisms to hold the plurality of anti - movement mechanisms in the delivery configuration. When delivered, the suture or wire is removed to allow the anti - movement mechanism to return to the angled configuration into which it is biased.

[0064] Any of the stents 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100 described above can include a cover 170 as described in relation to the stent 100 shown in FIG. 1.

[0065] Any angle described in connection with the above figures is merely exemplary, and it will be understood that other angles of the closed-loop movement prevention mechanism are also contemplated. The various components of the stents 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100 disclosed herein and the materials that can be used for the various elements thereof may include materials commonly associated with medical devices. For the sake of brevity, in the following description, reference will be made to stent 100 (and the variants, systems or components disclosed herein). However, this is not intended to limit the devices and methods described herein, and this description may also be applicable to other elements, members, components, or devices disclosed herein.

[0066] In some embodiments, the stent 100 (and the variations, systems, or components disclosed herein) disclosed herein can be made of metal, metal alloy, polymer (some examples of which are disclosed below), metal-polymer composite materials, combinations thereof, etc., or other suitable materials. Examples of suitable metals and alloys include stainless steels such as 444V, 444L, and 314LV stainless steels; mild steel; nickel-titanium alloys such as linear elastic and / or superelastic nitinol; cobalt-chromium alloys, titanium and its alloys, alumina, diamond-like carbon coating (DLC) or titanium nitride-coated metal, other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS:N06625 such as INCONEL® 625, UNS:N06022 such as HASTELLOY® C-22™, UNS:N10276 such as HASTELLOY® C276™, other HASTELLOY® alloys, etc.), nickel-copper alloys (e.g., UNS:N04400 such as MONEL® 400, NICKELVAC™ 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R44035 such as MP35-N™), nickel-molybdenum alloys (e.g., UNS:N10665 such as HASTELLOY® ALLOY B2™), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R44003 such as ELGILOY®, PHYNOX®); platinum enriched stainless steel; titanium; platinum; palladium; gold; combinations thereof; etc.; or other suitable materials are included.

[0067] As suggested herein, there is a category among commercially available nickel-titanium alloys or nitinol alloys called "linear elastic" or "non-superelastic". These may be chemically similar to conventional shape memory and superelastic types, but can exhibit unique useful mechanical properties. Linear elastic and / or non-superelastic nitinol can be distinguished from superelastic nitinol in that, in its stress-strain curve, it does not exhibit a substantial "superelastic plateau" or "flag region" like that of superelastic nitinol. Instead, in linear elastic and / or non-superelastic nitinol, as the recoverable strain increases, the stress continues to increase in a substantially or somewhat linear relationship (not necessarily a perfectly linear relationship) until plastic deformation begins, or at least in a relationship closer to linear than the superelastic plateau and / or flag region seen in superelastic nitinol. Thus, for the purposes of this disclosure, linear elastic and / or non-superelastic nitinol is also referred to as "substantially" linear elastic and / or non-superelastic nitinol.

[0068] In some examples, linear elastic and / or non-superelastic nitinol can also be distinguished from superelastic nitinol in that linear elastic and / or non-superelastic nitinol can accept up to about 2-5% strain while substantially maintaining elasticity (e.g., before plastic deformation), whereas superelastic nitinol can accept up to about 8% strain before plastic deformation. Both of these materials can be distinguished from other linear elastic materials, such as stainless steel, which can only accept up to about 0.2-0.44 percent strain before plastic deformation (and can also be distinguished by composition).

[0069] In some examples, linear elastic and / or non-superelastic nickel-titanium alloys are alloys that do not exhibit any martensite / austenite phase changes detectable by differential scanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA) over a wide temperature range. For example, in some embodiments, in linear elastic and / or non-superelastic nickel-titanium alloys, there may be no martensite / austenite phase changes detectable by DSC and DMTA analysis in the range of about -60 degrees Celsius (°C) to about 120 °C. Thus, the mechanical bending properties of such materials may typically be unaffected by temperature over this very wide temperature range. In some embodiments, the mechanical bending properties of linear elastic and / or non-superelastic nickel-titanium alloys at ambient temperature or room temperature are, for example, substantially the same as the mechanical properties at body temperature, at which temperature they do not exhibit a superelastic plateau and / or flag region. For example, over a wide temperature range, linear elastic and / or non-superelastic nickel-titanium alloys maintain their linear elastic and / or non-superelastic properties and / or characteristics.

[0070] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy may be one having nickel in the range of about 50 to about 60 weight percent and the balance being essentially titanium. In some embodiments, the composition is in the range of about 54 to about 57 weight percent nickel. An example of a suitable nickel-titanium alloy is the FHP-NT alloy commercially available from Furukawa Techno-Material Co., Ltd. in Kanagawa Prefecture, Japan. Other suitable materials include ULTANIUM (trademark) (available from Neo-Metrics) and GUM METAL (trademark) (available from Toyota). In some other embodiments, desired properties can be achieved by using superelastic alloys, such as superelastic nitinol.

[0071] In at least some embodiments, some or all of the stent 100 (and the variations, systems, or components disclosed herein) disclosed herein may be doped with a radiopaque material, made of a radiopaque material, or otherwise include a radiopaque material. A radiopaque material is understood to be a material that can generate a relatively bright image on a fluoroscopic screen or other imaging techniques during a medical procedure. This relatively bright image helps the user to determine the position of the stent 100 (and the variations, systems, or components disclosed herein) disclosed herein. Some examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials filled with radiopaque fillers, and the like. Additionally, other radiopaque marker bands and / or coils can also be incorporated into the design of the stent 100 (and the variations, systems, or components disclosed herein) disclosed herein to achieve the same result.

[0072] In some embodiments, the stent 100 (and the variants, systems, or components disclosed herein) disclosed herein or a part thereof can be made of or include a polymer or other suitable material. Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block ester, polyurethane (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether ester (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalate and / or other polyester elastomers, e.g., HYTREL® available from DuPont), polyamide (e.g., DURETHAN® available from Bayer or CRISTAMID™ available from Elf Atochem), elastomeric polyamide, block polyamide / ether, polyether block amide (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), MARLEX® high density polyethylene, MARLEX® low density polyethylene, linear low density polyethylene (e.g., REXELL™), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyether imide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (EMS AmericanGRILAMID (registered trademark), etc. available from Grilon, perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, ionomer, polyurethane silicone copolymer (e.g., Elast-Eon (registered trademark) available from AorTech Biomaterials or ChronoSil (registered trademark) available from AdvanSource Biomaterials), biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, etc. thereof. In some embodiments, the sheath can be blended with a liquid crystal polymer (LCP). For example, the mixture can contain up to about 6 percent LCP.

[0073] In some embodiments, the stent 100 disclosed herein (and the variations, systems, or components disclosed herein) may include a suitable therapeutic agent and / or may be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents include antithrombotic agents (such as heparin, heparin derivatives, urokinase, and PPack (dextrorphan proline arginine chloromethyl ketone)); antiproliferative agents (such as enoxaparin, angiopep, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory agents (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine); antitumor / antiproliferative / antimitotic agents (such as paclitaxel, 5-fluorouracil, cisplatin, vincristine, vinblastine, epothilone, endostatin, angiostatin, and thymidine kinase inhibitors); anesthetics (such as lidocaine, bupivacaine, and ropivacaine); anticoagulants (such as D-Phe-Pro-Arg chloromethyl ketone, RGD peptide-containing compounds, heparin, antithrombin compounds, platelet receptor antagonists, antithrombin antibodies, antiplatelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick antiplatelet peptides); vasocyte proliferation promoters (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional activators, and translation promoters); vasocyte proliferation inhibitors (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional repressors, translation repressors, replication inhibitors, inhibitory antibodies, antibodies against growth factors, bifunctional molecules consisting of a growth factor and a cytotoxin, bifunctional molecules consisting of an antibody and a cytotoxin); cholesterol-lowering agents; vasodilators; and agents that interfere with the endogenous vasomotor mechanism.

[0074] It should be understood that the present disclosure is illustrative in many respects. Without exceeding the scope of the present disclosure, changes can be made in details, particularly with regard to the shape, size, and order of steps. This may include, within a suitable range, using any of the features of one exemplary embodiment in other embodiments. Of course, the scope of the present disclosure is defined by the language expressed in the appended claims.

Claims

**Claim 1** A stent, comprising: a tubular body formed from woven wires, the tubular body having a first open end, an opposite second open end, and a central longitudinal axis extending between the first open end and the second open end, the tubular body being movable between a radially compressed state and a radially expanded state; and a plurality of anti-migration mechanisms, each anti-migration mechanism having a first end disposed on an outer surface of the tubular body and a second end extending radially outward from the outer surface of the tubular body. Each of the plurality of anti-migration mechanisms is formed by a closed loop of one or more woven wires, the base of the closed loop being located on the outer surface of the tubular body. **Claim 2** The stent according to claim 1, wherein the base of the closed loop includes intersections of the one or more woven wires forming the closed loop. **Claim 3** The stent according to claim 2, wherein the one or more woven wires are welded at the intersections. **Claim 4** Any tensile or compressive force applied to any of the plurality of anti-migration mechanisms does not decrease the outer diameter of the tubular body or cause the tubular body to be axially stretched or shortened. The stent according to any one of claims 1 to 3. **Claim 5** A first portion of the plurality of anti-migration mechanisms is coupled to the tubular body adjacent the first open end and extends at an acute angle toward the second open end with respect to the outer surface of the tubular body. The stent according to any one of claims 1 to 4. **Claim 6** A second portion of the plurality of anti-migration mechanisms is coupled to the tubular body adjacent the second open end and extends at an acute angle toward the first open end. The stent according to claim 5. **Claim 7** A first portion of the plurality of anti-migration mechanisms is coupled to an intermediate region of the tubular body and extends at an acute angle toward the first open end, and a second portion of the plurality of anti-migration mechanisms is coupled to the intermediate region of the tubular body and extends at an acute angle toward the second open end. The stent according to claim 1. **Claim 8** The base of each anti - movement mechanism of the first part and the base of each anti - movement mechanism of the second part are circumferentially spaced apart at a single longitudinal position along the tubular body. The stent according to claim 7.

9. The plurality of closed loops forming the plurality of anti - movement mechanisms are arranged at the first open end and extend radially outward from the tubular body. The stent according to claim 1.

10. At the first open end, the stent according to claim 9 further comprises a plurality of elongated closed loops extending substantially parallel to the central longitudinal axis.

11. The plurality of elongated closed loops are inserted between adjacent closed loops among the plurality of closed loops forming the plurality of anti - movement mechanisms. The stent according to claim 10.

12. Each closed loop is formed by a plurality of woven wires, and a plurality of ends of the plurality of woven wires are welded to the periphery of the closed loop. The stent according to any one of claims 1 to 11.

13. Each closed loop is formed by a part of four woven wires that collectively form the periphery of the closed loop. The stent according to claim 12.

14. A stent comprising: A tubular body formed of woven wires, the tubular body having a first open end, an opposite second open end, and a central longitudinal axis extending between the first open end and the second open end, the tubular body being movable between a radially compressed state and a radially expanded state. The tubular body; A plurality of anti - movement mechanisms, each having a first end welded to one or more intersections of one or more woven wires forming the tubular body and a second end extending radially outward from the outer surface of the tubular body. A stent comprising the plurality of anti - movement mechanisms.

15. A stent comprising: A radially expandable tubular body formed of woven wires, the tubular body having a first open end, an opposite second open end, and a central longitudinal axis extending between the first open end and the second open end, the tubular body being movable between a radially compressed state and a radially expanded state. The tubular body; A plurality of anti-movement mechanisms located at the first open end portion, each of the plurality of anti-movement mechanisms having a first end portion disposed on the outer surface of the tubular body and a second end portion extending radially outward from the outer surface of the tubular body, and the plurality of anti-movement mechanisms. Each of the plurality of anti-movement mechanisms is formed into a closed loop by a plurality of woven wires, and the ends of the plurality of wires are disposed at the periphery of the closed loop, a stent.

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