Supports, mandrels, and methods for forming supports with anti-migration features

Abstract

A medical stent having a first end, a second end, and a central longitudinal axis extending from the first end to the second end, the medical stent can include a plurality of first filaments each extending in a first helical path about the central longitudinal axis in a first direction and a plurality of second filaments each extending in a second helical path about the central longitudinal axis in a second direction. The plurality of first filaments can be interwoven with the plurality of second filaments. The first helical path of at least one filament of the plurality of first filaments can include a circumferential offset disposed between the first end and the second end.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 62 / 969,498, filed February 3, 2020, the disclosure of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to a stent, and a mandrel and a method for forming a stent. More particularly, the present disclosure relates to a stent having anti-migration features, a mandrel for forming a stent having anti-migration features, and a method of forming a stent having anti-migration features. BACKGROUND

[0004] Stents can be configured to be positioned in a body lumen for a variety of medical applications. For example, stents can be used to treat a stenosis in a blood vessel, to maintain a fluid opening or passageway in a blood vessel, urinary tract, biliary tract, tracheobronchial, esophageal, or renal tubule, or in some cases to position a device, such as a prosthetic valve or filter, inside a body lumen. In some cases, a stent can include anti-migration features to help secure the stent in place, regardless of which body lumen the stent is placed in. In certain cases, it is difficult to accurately and repeatably form these anti-migration features. Known medical devices and manufacturing methods each have certain advantages and disadvantages. There is an ongoing need for alternative medical devices and manufacturing methods. SUMMARY

[0005] In one example, a medical stent having a first end, a second end, and a central longitudinal axis extending from the first end to the second end can include a plurality of first filaments each extending in a first helical path around the central longitudinal axis in a first direction, and a plurality of second filaments each extending in a second helical path around the central longitudinal axis in a second direction. The plurality of first filaments can be interwoven with the plurality of second filaments. The first helical path of at least one filament of the plurality of first filaments can include a circumferential offset disposed between the first end and the second end.

[0006] In addition or alternatively to any example disclosed herein, at least one filament of the plurality of first filaments includes an anti-migration ring that protrudes radially outward from an outer surface of the medical stent at the circumferential offset.

[0007] In addition or alternatively to any example disclosed herein, the circumferential offset forms the anti-migration ring.

[0008] In addition or alternatively to any example disclosed herein, at least a portion of the anti-migration ring is oriented substantially perpendicular to the central longitudinal axis.

[0009] Except or in addition to any examples disclosed herein, a portion of the anti-migration ring is angled toward the first end or the second end of the medical stent.

[0010] Except or in addition to any examples disclosed herein, the plurality of first filaments and the plurality of second filaments are interwoven together defining a plurality of intersection points.

[0011] Except or in addition to any examples disclosed herein, the first helical path of at least one filament of the plurality of first filaments passes under a first one of the plurality of second filaments at the first end of the circumferential offset and passes under a second one of the plurality of second filaments at the second end of the circumferential offset.

[0012] Except or in addition to any examples disclosed herein, the first helical path of at least one filament of the plurality of first filaments includes a plurality of circumferential offsets longitudinally spaced from one another between the first end and the second end.

[0013] Except or in addition to any examples disclosed herein, the first helical path of some of the plurality of first filaments each have a circumferential offset disposed between the first end and the second end.

[0014] Except or in addition to any examples disclosed herein, a mandrel for forming a medical stent can include a cylindrical body and a plurality of protrusions extending radially outward from the cylindrical body. The plurality of protrusions can define a plurality of first channels helically extending around the cylindrical body in a first direction and a plurality of second channels helically extending around the cylindrical body in a second direction. At least some of the plurality of protrusions can have a groove formed therein extending around the cylindrical body in a circumferential direction.

[0015] Except or in addition to any examples disclosed herein, at least some of the plurality of protrusions including the groove formed therein are raised protrusions that extend further radially outward from the cylindrical body than the remaining protrusions of the plurality of protrusions.

[0016] Except or in addition to any examples disclosed herein, the groove is oriented substantially perpendicular to a central longitudinal axis of the cylindrical body.

[0017] Except or in addition to any examples disclosed herein, the groove communicates adjacent ones of the plurality of first channels.

[0018] Except or in addition to any examples disclosed herein, the at least some of the plurality of protrusions having the groove formed therein form a circumferential row of protrusions extending around the cylindrical body.

[0019] In addition to or in place of any of the examples disclosed herein, a method of manufacturing a medical stent can include: using a mandrel including a cylindrical body and a plurality of protrusions extending radially outward from the cylindrical body, wherein the plurality of protrusions define a plurality of first channels extending helically around the cylindrical body in a first direction and a plurality of second channels extending helically around the cylindrical body in a second direction, wherein at least some of the plurality of protrusions include a groove formed therein extending around the cylindrical body in a circumferential direction; and wrapping a plurality of first filaments around the mandrel inside the plurality of first channels and wrapping a plurality of second filaments around the mandrel inside the plurality of second channels such that the plurality of first filaments are interwoven with the plurality of second filaments to define a body of the medical stent. At least some of the plurality of first filaments can be wrapped over at least some of the plurality of protrusions including the groove formed therein.

[0020] In addition to or in place of any of the examples disclosed herein, wrapping at least some of the plurality of first filaments over at least some of the plurality of protrusions having the groove formed therein can form a plurality of anti-migration rings extending radially outward from the body of the medical stent.

[0021] In addition to or in place of any of the examples disclosed herein, each first filament wrapped over at least some of the plurality of protrusions having the groove formed therein extends under one of the plurality of second filaments adjacent a first end of the groove and under one of the plurality of second filaments adjacent a second end of the groove.

[0022] In addition to or in place of any of the examples disclosed herein, each anti-migration ring extends radially outward from the body of the medical stent between two adjacent second filaments.

[0023] In addition to or in place of any of the examples disclosed herein, the groove formed in at least some of the plurality of protrusions extends around the cylindrical body in a circumferential direction.

[0024] In addition to or in place of any of the examples disclosed herein, wrapping at least some of the plurality of first filaments over at least some of the plurality of protrusions including the groove formed therein causes the first filaments to migrate from one first channel to an adjacent first channel.

[0025] The above summary of some implementations, aspects and / or examples is not intended to describe each embodiment or every implementation of the present disclosure. The figures and the detailed description that follow more particularly exemplify these implementations. BRIEF DESCRIPTION OF DRAWINGS

[0026] The present application can be more fully understood from the following detailed description, taken in connection with the accompanying drawings, in which:

[0027] FIG. 1A is a schematic illustration of selected aspects of a stent;

[0028] FIG. IB is a schematic end view of the stent of FIG. 1A;

[0029] FIG. 2 illustrates selected aspects of an exemplary mandrel used to form the stent of FIGS. 1A-1B;

[0030] FIG. 3 is a detailed view illustrating selected aspects of the stent of FIGS. 1A-1B;

[0031] Figure 4A is a schematic illustration of selected aspects of a stent;

[0032] Figure 4B is a schematic end view of the stent of Figure 4A

[0033] Figure 5 illustrates selected aspects of an exemplary mandrel used to form the stent of Figures 4A-4B

[0034] Figure 6 is a detailed view illustrating selected aspects of the stent of Figures 4A-4B

[0035] Figure 7 is a detailed view illustrating selected aspects of an alternative configuration of the stent of Figures 4A-4B

[0036] Figure 8 is a detailed view illustrating selected aspects of an alternative configuration of the stent of Figures 4A-4B

[0037] Figures 9A-9B is a schematic illustration describing aspects of a stent and a method of making the stent of Figures 4A-4B

[0038] Figure 10 is a detailed view illustrating selected aspects of the stent of FIGS. 1A-1B formed using an exemplary mandrel of Figure 5 Figures 4A-4B

[0039] Figure 11 is a schematic illustration of selected aspects of an alternative configuration of the stent of Figures 4A-4B

[0040] Figure 12 is a detailed view illustrating selected aspects of an alternative configuration of the stent of Figure 11

[0041] ​​​​​​​​​​While the application is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the application to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the application. DETAILED DESCRIPTION

[0042] The following description should be read with reference to the drawings, in which like reference numerals represent like parts throughout the several views. The detailed description and drawings are intended to illustrate but not limit the application. Those skilled in the art will recognize that the various elements described and illustrated can be arranged in various combinations and configurations, all of which are intended to fall within the scope of the disclosure. The detailed description and drawings illustrate exemplary embodiments of the application. However, for clarity and understanding, while each feature and / or element can not be shown in each figure, it is understood that these features and / or elements can be present in one or more figures, unless otherwise noted.

[0043] For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification.

[0044] All numerical values herein are assumed to be modified by the word "about," whether or not explicitly indicated. In the context of a numerical value, the word "about" generally refers to a range of numbers that a person of skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the word "about" can include numbers that are rounded to the nearest significant figure. Other uses of the word "about" (e.g., in contexts other than numerical values) can assume their ordinary and customary meaning, as understood from the specification and consistent with the context in which they are used, unless otherwise specified.

[0045] Recitation of ranges of values includes all values between the recited minimum and maximum values (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0046] While some suitable dimensions, ranges, and / or values that pertain to various components, features, and / or specifications are disclosed, one of skill in the art, in light of the present disclosure, will appreciate that desired dimensions, ranges, and / or values can deviate from the explicitly disclosed dimensions, ranges, and / or values.

[0047] As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. As used in the specification and the appended claims, the term "or" is generally used in the sense that it is used in the context of the application, i.e., the traditional sense of "and / or," unless the context clearly dictates otherwise. It should be noted that for ease of understanding, certain features of the disclosure can be described singularly even if the features are plural or repeated within the disclosed embodiments. Individual instances of these features can include and / or be encompassed by the singularly disclosed features unless expressly stated to the contrary. For the sake of brevity and clarity, all elements of the disclosed embodiments need not necessarily be shown in each diagram, or discussed in detail, above. However, it will be understood that the following discussion can apply to any and / or all of the elements, where applicable, unless expressly stated to the contrary. Furthermore, for the sake of clarity, not all instances of some elements or features can be shown in each diagram.

[0048] Relative terms such as "proximal," "distal," "travel," "retract," variations thereof, and the like can generally be taken in reference to the positioning, orientation, and / or manipulation of various elements relative to a user / operator / handler of the device, where "proximal" and "retract" indicate or refer to closer to or toward the user, and "distal" and "travel" indicate or refer to further from or away from the user. In some cases, for ease of understanding of the disclosure, the terms "proximal" and "distal" can be arbitrarily assigned, and such will be readily understood by one of skill in the art. Other relative terms such as "upstream," "downstream," "inflow," and "outflow" refer to the direction of fluid flow within a cavity (such as a body cavity, a blood vessel) or within a device.

[0049] It should be noted that a reference to "an embodiment," "some embodiments," "other embodiments," etc., in this specification and throughout the claims means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in the specification are generally not intended to signify that exactly the same feature, structure, or characteristic of an embodiment is being described. Furthermore, it is appreciated that the features, structures, or characteristics of one embodiment can be incorporated into other embodiments in a manner known to those of skill in the art. Also, it should be understood that the description herein is in terms of the best information available to the applicant at the time of the filing of this application. However, it is also understood that the applicant could make changes to the description herein after the filing of this application, and it is intended that the description herein be construed as including such changes unless otherwise expressly indicated.

[0050] For purposes of clarity, certain identified embodiments of the application are described herein with acertain degree of particularity. However, the application is not limited to the embodiments described, and any reference to a particular embodiment is intended merely to clarify the description, and not to limit the application. The description is intended to cover any and all modifications and variations of the embodiments described herein. It is intended that the scope of the application be defined by the claims appended hereto, rather than the description of the embodiments. It is intended that each of the embodiments described herein apply to all other embodiments, mutatis mutandis. It is also possible to make variations to the embodiments described herein while still remaining within the scope of the application. Furthermore, where a range of values is provided, it is intended that every narrower range that falls within the broader range is also intended to be encompassed. Numerous specific details of the application are described below with the understanding that the application includes all variations of embodiments described herein. Accordingly, although the application is described with reference to specific on-premises and cloud-based embodiments, it is not intended that the application be limited thereto. Those skilled in the art with access to the teachings provided herein will recognize additional modifications and embodiments within the scope and spirit of the application.

[0051] FIGS. 1A and IB are schematic illustrations of a prior art stent 10. The prior art stent 10 can be defined by a central longitudinal axis extending between a first end 18 and a second end 20 and / or can have a central longitudinal axis 12 extending between the first end 18 and the second end 20. The prior art stent 10 can include a body 16 defining a generally cylindrical outer surface 14. The body 16 can extend from the first end 18 to the second end 20. In prior art stents 10 having flared end portions (not shown), the body 16 can extend between the flared end portions of the prior art stent 10. The prior art stent 10 and / or the body 16 can include a plurality of first filaments 30 extending in a first direction about the central longitudinal axis 12 and a plurality of second filaments 40 extending in a second direction about the central longitudinal axis 12.

[0052] FIG. 2 illustrates a portion of an exemplary prior art mandrel 80 used to form the prior art stent 10. The prior art mandrel 80 can include protrusions 82 extending radially outward from a mandrel body to define a plurality of first channels 86 and a plurality of second channels 88. The outer surface of the mandrel body can define the base of the channels 86 / 88. The plurality of first filaments 30 and the plurality of second filaments 40 can be disposed between the protrusions 82 inside the channels 86 / 88 to form the prior art stent 10 such that the prior art stent 10 has a generally uniform diameter and / or outer surface. FIG. 3 is a detailed view illustrating a portion of the prior art stent 10 in which the plurality of first filaments 30 and the plurality of second filaments 40 are interwoven together to form a braided tubular member. The interwoven first filaments 30 and second filaments 40 can define the outer surface of the prior art stent 10.

[0053] Figure 4A and Figure 4BAspects of a medical stent 110 according to the present disclosure are schematically illustrated. The medical stent 110 can have a first end 118, a second end 120, and a central longitudinal axis 112 extending from the first end 118 to the second end 120. The medical stent 110 can include a tubular body 116 defining a lumen extending therethrough from the first end 118 to the second end 120. The tubular body 116 can define an outer surface 114 of the stent 110. In some embodiments, the body 116 can extend from the first end 118 to the second end 120. In some embodiments, the medical stent 110 can include a flared first end (not shown) and / or a flared second end (not shown). In these embodiments, the body 116 of the medical stent 110 can extend from the first end 118 to a flared second end, from a flared first end to the second end 120, or from a flared first end to a flared second end. Other arrangements are also contemplated.

[0054] The following description assumes that the body 116 extends from the first end 118 of the medical stent 110 to the second end 120 of the medical stent 110. In other configurations, the first end 118 and the second end 120 can be considered to refer to a first end of the body 116 and a second end of the body 116, respectively. The body 116 of the medical stent 110 can have a generally constant and / or uniform outer diameter and / or outer surface 114, however, as noted above, in some cases the body 116 can include one or more flared ends.

[0055] The tubular body 116 can be composed of a plurality of interwoven filaments, such as a plurality of braided filaments extending in a helical direction along a length of the tubular body while crossing over one another to form a braided tubular frame. For example, the medical stent 110 can include a plurality of first filaments 130, each first filament 130 extending from the first end 118 toward and / or to the second end 120 in a first helical path about the central longitudinal axis 112 in a first direction (i.e., a first helical direction). In some embodiments, the first direction can be a clockwise direction. The medical stent 110 can include a plurality of second filaments 140, each second filament 140 extending from the first end 118 toward and / or to the second end 120 in a second helical path about the central longitudinal axis 112 in a second direction (i.e., a second helical direction). In some embodiments, the second direction can be opposite the first direction. In some embodiments, the second direction can be a counterclockwise direction.

[0056] In some embodiments, the first helical path of at least one filament of the plurality of first filaments 130 can have a circumferential offset disposed along the body 116 between the first end 118 and the second end 120. For example, at least one filament of the plurality of first filaments 130 can include a first helically extending portion, a second helically extending portion circumferentially offset from and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion.

[0057] In some embodiments, the first helical path of the plurality of first filaments 130 of the plurality of first filaments can each include a circumferential offset along the body 116 between the first end 118 and the second end 120. In some embodiments, the first helical path of each and / or all of the plurality of first filaments 130 can include a circumferential offset disposed along the body 116 between the first end 118 and the second end 120. For example, each and / or all of the plurality of first filaments 130 can include a first helically extending portion, a second helically extending portion circumferentially offset from and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion. Thus, the circumferential offset can be formed as an integral section (e.g., arcuate section) of the filaments of the tubular body, with the arcuate section of the filaments forming the circumferential offset being located between first and second helically extending portions of the filaments that are interwoven with other filaments of the tubular body that extend helically about the tubular body. The circumferential offset can have a first base and a second base, with the filaments curving outward from the circumference of the tubular body at the bases, and a radially outwardly projecting portion (e.g., arcuate portion) of the circumferential offset extending between the two bases. The circumferential offset can be oriented perpendicular to the longitudinal axis of the expandable frame, such that the bases of the circumferential offset are longitudinally aligned at a common longitudinal location along the tubular body and at circumferentially spaced locations along the tubular body.

[0058] Additionally or alternatively, in some embodiments, the second helical path of at least one filament of the plurality of second filaments 140 can include a circumferential offset disposed along the body 116 between the first end 118 and the second end 120. For example, at least one filament of the plurality of second filaments 140 can include a first helically extending portion, a second helically extending portion circumferentially offset from and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion. In some embodiments, the second helical paths of the multiple second filaments of the plurality of second filaments 140 can each include a circumferential offset along the body 116 between the first end 118 and the second end 120. In some embodiments, the second helical path of each and / or all of the plurality of second filaments 140 can include a circumferential offset disposed along the body 116 between the first end 118 and the second end 120. For example, each and / or all of the plurality of second filaments 140 can include a first helically extending portion, a second helically extending portion circumferentially offset from and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion. Thus, the circumferential offset can be formed as an integral segment (e.g., arcuate segment) of the tubular body, with the arcuate segment of the filament constituting the circumferential offset being positioned between the first helically extending portion and the second helically extending portion of the filament helically extending around the expandable framework interwoven with other filaments of the tubular body. The circumferential offset can have a first base and a second base, with the filament curving outward from the circumference of the tubular body and a radially outward protrusion (e.g., arcuate portion) of the circumferential offset extending between the two bases. The circumferential offset can be oriented perpendicular to the longitudinal axis of the tubular body, such that the bases of the circumferential offset are longitudinally aligned at a common longitudinal position and at circumferentially spaced positions along the tubular body.

[0059] In some embodiments, at least one filament of the plurality of first filaments 130 (and / or at least one filament of the plurality of second filaments 140, if so configured) can include an anti-migration ring 150 protruding radially outward from the outer surface 114 of the body 116 of the medical stent 110 at the circumferential offset. In some embodiments, the circumferential offset forms at least a portion of the anti-migration ring 150. In some embodiments, the circumferential offset forms the anti-migration ring 150. In some embodiments, each filament of the plurality of first filaments 130 (and / or the plurality of second filaments 140) can include a circumferential offset and / or an anti-migration ring 150. Although the anti-migration ring 150 is illustrated in FIGS. 1-3 as being disposed at the center of the body 116 of the medical stent 110, the anti-migration ring 150 can be disposed at any location along the length of the body 116 of the medical stent 110. Figure 4A and Figure 4B In some embodiments, at least one filament of the plurality of first filaments 130 (and / or at least one filament of the plurality of second filaments 140, if so configured) can include an anti-migration ring 150 protruding radially outward from the outer surface 114 of the body 116 of the medical stent 110 at the circumferential offset. In some embodiments, the circumferential offset forms at least a portion of the anti-migration ring 150. In some embodiments, the circumferential offset forms the anti-migration ring 150. In some embodiments, each filament of the plurality of first filaments 130 (and / or the plurality of second filaments 140) can include a circumferential offset and / or an anti-migration ring 150. Although the anti-migration ring 150 is illustrated in FIGS. 1-3 as being disposed at the center of the body 116 of the medical stent 110, the anti-migration ring 150 can be disposed at any location along the length of the body 116 of the medical stent 110.

[0060] In some embodiments, the plurality of anti-migration rings 150 projecting radially outward from the outer surface 114 of the main body 116 of the medical stent 110 can form a circumferentially aligned row of anti-migration rings 150 extending around the main body 116 of the medical stent 110. In some embodiments, the plurality of anti-migration rings 150 in the circumferentially aligned row of anti-migration rings 150 can be axially and / or circumferentially aligned at a common axial location along the central longitudinal axis 112 of the medical stent 110.

[0061] In some embodiments, at least a portion of the anti-migration rings 150 can be oriented substantially perpendicular to the central longitudinal axis 112 of the medical stent 110. Anti-migration rings 150 oriented perpendicular to the central longitudinal axis 112 can make the medical stent 110 more resistant to axial migration in situ compared to anti-migration rings oriented at an oblique angle relative to the central longitudinal axis 112.

[0062] Figure 5 Aspects of a mandrel 180 for forming a medical stent 110 are illustrated. The mandrel 180 can include a generally cylindrical body and a plurality of protrusions 182 extending radially outward from the cylindrical body. In some embodiments, the plurality of protrusions 182 can be integral with and / or integrally formed with the cylindrical body. For example, the cylindrical body and the plurality of protrusions 182 can be made from a unitary material, such as by cutting, machining, etching, grinding, casting, injection molding, etc.

[0063] In some embodiments, the plurality of protrusions 182 can have a generally diamond- shaped and / or pyramidal shape. For example, the plurality of protrusions 182 can taper from a wider base at the cylindrical body to a narrower tip at the outermost radial end of the central longitudinal axis of the mandrel 180 and / or cylindrical body. In some embodiments, one or more or each of the plurality of protrusions 182 can lack a "point" at its outermost radial end, thereby defining a somewhat flat "tip" of the protrusion. In some embodiments, the "tip" of the protrusion can have a curved or arcuate surface at the "tip" of the protrusion relative to and / or defined by the radius of the mandrel 180 and / or the radius of the cylindrical body from the central longitudinal axis of the mandrel 180 and / or cylindrical body. In some embodiments, the plurality of protrusions 182 can have a generally uniform height and / or can extend to a generally common radial span relative to the central longitudinal axis of the mandrel 180 and / or cylindrical body. Other configurations are also contemplated.

[0064] The plurality of protrusions 182 can define a plurality of first channels 186 that extend helically around the cylindrical body in a first direction from the first end of the mandrel 180 toward the second, opposite end of the mandrel 180. In some embodiments, the first direction can be a clockwise direction. The plurality of protrusions 182 can also define a plurality of second channels 188 that extend helically around the cylindrical body in a second direction opposite the first direction from the first end of the mandrel 180 toward the second, opposite end of the mandrel 180. In some embodiments, the second direction can be a counterclockwise direction.

[0065] In at least some embodiments, the cylindrical body can form and / or define a base or bottom of the plurality of first channels 186 and / or the plurality of second channels 188. For example, the cylindrical body can constitute a radially innermost extent of the plurality of first channels 186 and / or the plurality of second channels 188 relative to a central longitudinal axis of the mandrel 180 and / or the cylindrical body. In some embodiments, the plurality of protrusions 182 can define opposite sides of the plurality of first channels 186 and / or the plurality of second channels 188. In some embodiments, the plurality of first channels 186 and / or the plurality of second channels 188 can be radially outwardly open from the cylindrical body and / or relative to the central longitudinal axis of the mandrel 180 and / or the cylindrical body. In some embodiments, the plurality of first channels 186 and / or the plurality of second channels 188 can be wider at a radially outward extent of the plurality of first channels 186 and / or the plurality of second channels 188 than at a base or bottom of the plurality of first channels 186 and / or the plurality of second channels 188.

[0066] In some embodiments, at least some of the plurality of protrusions 182 have a groove 190 formed therein (e.g., in the "top" of the protrusion), which can extend around the cylindrical body. The groove 190 can open radially outward from the protrusion, from the cylindrical body, and / or relative to the central longitudinal axis of the mandrel 180 and / or the cylindrical body. In some embodiments, the groove 190 can be oriented substantially perpendicular to the central longitudinal axis of the mandrel 180 and / or the cylindrical body. For example, a centerline of the groove 190 can be disposed in a plane oriented perpendicular to the central longitudinal axis of the mandrel 180 and / or the cylindrical body. In some embodiments, the groove 190 can communicate adjacent first channels of the plurality of first channels 186. In some embodiments, the groove 190 can communicate adjacent second channels of the plurality of channels 188. In some embodiments, a circumferential row of protrusions having grooves 190 formed therein of the plurality of protrusions 182 of the mandrel 180 extend around the cylindrical body. In some embodiments, the grooves 190 of each protrusion of a circumferential row of protrusions having grooves 190 formed therein can be axially and / or circumferentially aligned at a common axial location along the central longitudinal axis of the mandrel 180 and / or the cylindrical body.

[0067] In some embodiments, at least some of the plurality of protrusions 182 having a groove 190 formed therein can be a raised protrusion 184 extending further radially outward from the cylindrical body and / or relative to the central longitudinal axis of the mandrel 180 and / or the cylindrical body than the remainder of the plurality of protrusions 182, such as shown in FIG. 1 1 1. Figure 5 Figure 5 While raised protrusions 184 having grooves 190 and thus also forming circumferential rows of protrusions extending around the cylindrical body are shown, raised protrusions 184 are not expressly required in every embodiment, and the mandrel 180 can be made without raised protrusions 184 as described herein using only the plurality of protrusions 182, wherein at least some of the plurality of protrusions 182 having grooves 190 formed therein.

[0068] In some embodiments, at least some of the plurality of protrusions 182 having a groove 190 formed therein can form a plurality of circumferential rows of protrusions extending around the cylindrical body. In some embodiments, the grooves 190 of each protrusion of one circumferential row of protrusions having grooves 190 formed therein can be axially and / or circumferentially aligned at a common axial location along the central axis of the mandrel 180 and / or the cylindrical body. The plurality of circumferential rows of protrusions can be longitudinally spaced from one another along the mandrel 180 and / or the cylindrical body.

[0069] Figure 6 ​is a detailed view illustrating a portion of a medical stent 110 as described herein. Those skilled in the art will recognize that, in order to illustrate the relationship between certain features, Figure 6 is not shown straight in side view. Rather, a slight angle has been introduced into the view, allowing the feature to be more easily seen and understood. Further, one filament of the plurality of first filaments 130 is shown with shading, such that the filament and first helical path are clearly shown to the viewer, not intended to represent a cross-section.

[0070] As described herein, the medical stent 110 can include a plurality of first filaments 130 and a plurality of second filaments 140. At least one filament of the plurality of first filaments 130 can include a circumferential offset disposed between the first helical extension and the second helical extension. The circumferential offset can form an anti-migration ring 150. In at least some embodiments, the plurality of first filaments 130 can be interwoven with the plurality of second filaments 140, for example when forming a braid. Figure 6 An over-under-over pattern of interwoven filaments is shown. Other configurations and / or patterns are also contemplated.

[0071] In some embodiments, interweaving the plurality of first filaments 130 with the plurality of second filaments 140 defines a plurality of intersections, where the first filaments and the second filaments cross over and / or under each other. The first helical path of at least one filament of the plurality of first filaments 130 can pass under a first filament of the plurality of second filaments 140 at the circumferential offset and / or first end 152 of the anti-migration ring 150 and can pass under a second filament of the plurality of second filaments 140 at the circumferential offset and / or second end 154 of the anti-migration ring 150. In at least some embodiments, a second filament of the plurality of second filaments 140 can be adjacent to a first filament of the plurality of second filaments 140. In this arrangement, at least one filament of the plurality of first filaments 130 (for example, Figure 6 the hatched filament) can pass under both adjacent filaments of the plurality of second filaments 140. This is made possible by the formation of the circumferential offset and the anti-migration ring 150, which extends radially outward from the outer surface 114 of the body 116 of the medical stent 110 between two adjacent intersections of the plurality of first filaments 130 and the plurality of second filaments 140.

[0072] In some embodiments, the medical stent 110 can be a covered stent. Thus, the medical stent 110 can include a covering 160 disposed on and / or attached to the plurality of first filaments 130 and the plurality of second filaments 140. The covering 160 can span the gaps between adjacent filaments of the plurality of first filaments 130 and the plurality of second filaments 140. In at least some embodiments, the covering 160 can be impermeable to fluid, debris, and / or tissue ingrowth. In some embodiments, the covering 160 can extend along the body of the medical stent 110 from the first end to the second end. In some embodiments, the covering 160 can extend along the full length of the medical stent 110. In some embodiments, the covering 160 can be disposed on the inner surface of the body, the outer surface of the body, both the inner and outer surfaces of the body, or the body can be embedded within the covering 160, with the anti-migration ring 150 protruding radially outward from the covering 160. Other configurations are also contemplated.

[0073] As discussed above and shown in FIGS. 1-3, the anti-migration ring 150 can be oriented substantially perpendicular to the central longitudinal axis of the medical stent 110. In one alternative configuration, a portion of the anti-migration ring 150 can be disposed obliquely toward the second end 120, as seen in FIG. 4. In some embodiments, only the radially outer portion (or less than the radially outer portion) of the anti-migration ring 150 can be disposed obliquely toward the second end 120, while the radially inner portion (or the remainder) of the anti-migration ring 150 can be oriented substantially perpendicular to the central longitudinal axis of the medical stent 110. In another alternative configuration, a portion of the anti-migration ring 150 can be disposed obliquely toward the first end 118, as seen in FIG. 5. In some embodiments, only the radially outer portion (or less than the radially outer portion) of the anti-migration ring 150 can be disposed obliquely toward the first end 118, while the radially inner portion (or the remainder) of the anti-migration ring 150 can be oriented substantially perpendicular to the central longitudinal axis of the medical stent 110. Other configurations are also contemplated. Figure 6 Figure 7 Figure 8

[0074] Figure 9A and Figure 9B ​​​Aspects of a first helical path and a second helical path for forming a medical stent 110 are schematically illustrated. To make the paths and / or various elements more clear and easier to understand, some features are shown in bold or with heavier lines to distinguish from adjacent features. Such depictions are not intended to or imply a difference in physical thickness (or other characteristic) of the features. As described above, the first helical path of at least one filament of the plurality of first filaments 130 can include a circumferential offset disposed along the body 116 between the first end 118 and the second end 120. The circumferential offset can form an anti-migration ring 150. The first helical path of at least one filament of the plurality of first filaments 130 can pass under a first filament of the plurality of second filaments 140 at the circumferential offset and / or the first end 152 of the anti-migration ring 150 and can pass under a second filament of the plurality of second filaments 140 at the circumferential offset and / or the second end 154 of the anti-migration ring 150. As can be seen in Figures 9A-9B at least one filament of the plurality of first filaments 130 can include a first helically extending portion (illustrated as sloping downward and to the right toward the anti-migration ring 150), a second helically extending portion (illustrated as sloping downward and to the right away from the anti-migration ring 150) circumferentially offset from the first helically extending portion and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion.

[0075] Figure 10 Aspects of a method of forming a medical stent 110 using a mandrel 180 are illustrated. The method can include using a mandrel 180 that can include a cylindrical body and a plurality of protrusions 182 extending radially outward from the cylindrical body. The plurality of protrusions 182 can define a plurality of first channels 186 extending helically around the cylindrical body in a first direction and a plurality of second channels 188 extending helically around the cylindrical body in a second direction opposite the first direction. At least some of the plurality of protrusions 182 include a groove 190 formed therein extending circumferentially around the cylindrical body.

[0076] The method can include wrapping a plurality of first filaments 130 around the mandrel 180 and / or the cylindrical body inside the plurality of first channels 186 in the first direction and wrapping a plurality of second filaments 140 around the mandrel 180 and / or the cylindrical body inside the plurality of second channels 188 in the second direction such that the plurality of first filaments 130 and the plurality of second filaments 140 are interwoven together to define a body of the medical stent 110.

[0077] The method can include wrapping at least some of the plurality of first filaments 130 over at least some of the plurality of protrusions 182 including the groove 190 formed therein. Wrapping at least some of the plurality of first filaments 130 over at least some of the plurality of protrusions 182 192 including the groove 190 formed therein can form a plurality of anti-migration rings 150 including the groove 190 formed therein extending radially outward from the body of the medical stent 110, as seen in Figure 10 The groove 190 formed in at least some of the plurality of protrusions 182 can extend circumferentially around the mandrel 180 and / or cylindrical body and / or central longitudinal axis thereof.

[0078] Wrapping at least some of the plurality of first filaments 130 over the plurality of protrusions 182 including the groove 190 formed therein will result in a circumferential offset of the first helical path of at least some of the plurality of first filaments 130. Wrapping at least some of the plurality of first filaments 130 over at least some of the plurality of protrusions 182 including the groove 190 formed therein can cause the first filaments to shift from one first channel to an adjacent first channel. Wrapping at least some of the plurality of first filaments 130 over the plurality of protrusions 182 including the groove 190 formed therein will also result in a circumferential extension of at least some of the plurality of first filaments 130 and / or anti-migration rings 150 extending radially outward from the body of the medical stent 110 comprised of and / or defined by the plurality of first channels 186 and the plurality of second channels 188. Each anti-migration ring 150 can extend radially outward from the body of the medical stent 110 between two adjacent second filaments of the plurality of second filaments 140.

[0079] As discussed herein, in some embodiments, at least some of the plurality of protrusions 182 including the groove 190 formed therein can be raised protrusions 184 extending further radially outward from the cylindrical body and / or relative to the central longitudinal axis of the mandrel 180 and / or cylindrical body than the remaining plurality of protrusions 182. Wrapping at least some of the plurality of first filaments 130 over the raised protrusions 184 will result in a circumferential extension of at least some of the plurality of first filaments 130 and / or anti-migration rings 150 extending even further radially outward from the body of the medical stent 110 than wrapping at least some of the plurality of first filaments 130 over the plurality of protrusions 182 including the groove 190 formed therein.

[0080] As discussed herein, in some embodiments, at least some of the plurality of protrusions 182 including the groove 190 formed therein can be raised protrusions 184 extending further radially outward from the cylindrical body and / or relative to the central longitudinal axis of the mandrel 180 and / or cylindrical body than the remaining plurality of protrusions 182. Wrapping at least some of the plurality of first filaments 130 over the raised protrusions 184 will result in a circumferential extension of at least some of the plurality of first filaments 130 and / or anti-migration rings 150 extending even further radially outward from the body of the medical stent 110 than wrapping at least some of the plurality of first filaments 130 over the plurality of protrusions 182 including the groove 190 formed therein. Figure 10As seen in the cross-section, each first filament of the at least some filaments of the plurality of first filaments 130 that are wrapped over at least some of the protrusions 182 including the groove 190 formed therein extend under a first one of the plurality of second filaments 140 at a first end of the groove 190 and / or adjacent to the first end, and under a second one of the plurality of second filaments 140 at a second end of the groove 190 and / or adjacent to the second end. The second one of the plurality of second filaments 140 can be adjacent to the first one of the plurality of second filaments 140. Each first filament of the at least some filaments of the plurality of first filaments 130 that are wrapped over at least some of the protrusions 182 including the groove 190 formed therein extend under a first one of the plurality of second filaments 140 at the circumferential offset and / or adjacent to the first end 152 of the anti-migration ring 150 and / or adjacent to the first end, and under a second one of the plurality of second filaments 140 at the circumferential offset and / or adjacent to the second end 154 of the anti-migration ring 150 and / or adjacent to the second end. In at least some embodiments, the circumferential offset and / or the first end 152 of the anti-migration ring 150 can be disposed inside the first end of the groove 190, and the circumferential offset and / or the second end 154 of the anti-migration ring 150 can be disposed inside the second end of the groove 190.

[0081] Figure 11 Aspects of an alternative medical stent 210 according to the present disclosure are schematically illustrated. The medical stent 210 can be formed in the same manner as the medical stent 110 and / or can include the same or similar features as the medical stent 110. Similar features can be labeled with similar reference numerals. The medical stent 210 can have a first end, a second end, and a central longitudinal axis 212 extending from the first end to the second end. The medical stent 210 can include a body 216 defining an outer surface 214. In some embodiments, the body 216 can extend from the first end to the second end. Other configurations described herein with respect to the medical stent 110 are also contemplated.

[0082] The medical stent 210 can include a plurality of first filaments 230, each first filament extending in a first helical path in a first direction around the central longitudinal axis 212 from the first end toward and / or to the second end. In some embodiments, the first direction can be a clockwise direction. The medical stent 210 can include a plurality of second filaments 240, each second filament 240 extending in a second helical path in a second direction around the central longitudinal axis 212 from the first end toward and / or to the second end. In some embodiments, the second direction can be opposite the first direction. In some embodiments, the second direction can be a counterclockwise direction.

[0083] In some embodiments, the first helical path of at least one filament of the plurality of first filaments 230 can include a circumferentially offset portion disposed along the body 216 between the first end and the second end. For example, at least one filament of the plurality of first filaments 230 can include a first helically extending portion, Circumferentially offset and a second helically extending portion circumferentially offset from and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion.

[0084] In some embodiments, the first helical path of some of the plurality of first filaments 230 can each include a circumferentially offset portion along the body 216 between the first end and the second end. In some embodiments, the first helical path of each and / or all of the plurality of first filaments 230 can include a circumferentially offset portion disposed along the body 216 between the first end and the second end. For example, each and / or all of the plurality of first filaments 230 can include a first helically extending portion, a second helically extending portion circumferentially offset from and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion. In some embodiments, the first helical path of at least one filament of the plurality of first filaments 230 includes a plurality of circumferentially offset portions longitudinally spaced from one another between the first end and the second end.

[0085] Additionally or alternatively, in some embodiments, the second helical path of at least one filament of the plurality of second filaments 240 can include a circumferentially offset portion disposed along the body 216 between the first end and the second end. For example, at least one filament of the plurality of second filaments 240 can include a first helically extending portion, a second helically extending portion circumferentially offset from and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion. In some embodiments, the second helical path of some of the plurality of second filaments 240 can each include a circumferentially offset portion along the body 216 between the first end and the second end. In some embodiments, the second helical path of each and / or all of the plurality of second filaments 240 can include a circumferentially offset portion disposed along the body 216 between the first end and the second end. For example, each and / or all of the plurality of second filaments 240 can include a first helically extending portion, a second helically extending portion circumferentially offset from and generally parallel to the first helically extending portion, and a circumferentially extending portion disposed between the first helically extending portion and the second helically extending portion. In some embodiments, the second helical path of at least one filament of the plurality of second filaments 240 includes a plurality of circumferentially offset portions longitudinally spaced from one another between the first end and the second end.

[0086] In some embodiments, at least one filament of the plurality of first filaments 230 (and / or at least one filament of the plurality of second filaments 240, where so configured) can include an anti-migration ring 250 that protrudes radially outward from the outer surface 214 of the main body 216 of the medical stent 210 at a circumferential offset. In some embodiments, the circumferential offset forms at least a portion of the anti-migration ring 250. In some embodiments, the circumferential offset forms the anti-migration ring 250. In some embodiments, each filament of the plurality of first filaments 230 (and / or the plurality of second filaments 240) can include a circumferential offset and / or an anti-migration ring 250. In some embodiments, at least one filament of the plurality of first filaments 230 (and / or at least one filament of the plurality of second filaments 240, where so configured) can include a plurality of anti-migration rings 250 that protrude radially outward from the outer surface 214 of the main body 216 of the medical stent 210 at a plurality of circumferential offsets.

[0087] In some embodiments, the plurality of anti-migration rings 250 that protrude radially outward from the outer surface 214 of the main body 216 of the medical stent 210 can form a plurality of circumferential rows of anti-migration rings 250 (a plurality of circumferential rows of anti-migration rings) that extend around the main body 216 of the medical stent 210. In some embodiments, the anti-migration rings 250 within one circumferential row of anti-migration rings 250 can be axially and / or circumferentially aligned at a common axial location along the central longitudinal axis 212 of the medical stent 210. The plurality of circumferential rows of anti-migration rings 250 can be longitudinally spaced from one another along the main body 216 of the medical stent 210.

[0088] In some embodiments, at least a portion of the anti-migration rings 250 can be oriented substantially perpendicular to the central longitudinal axis 212 of the medical stent 210. Anti-migration rings 250 oriented perpendicular to the central longitudinal axis 212 can cause the medical stent 210 to resist axial migration in situ more than anti-migration rings oriented at an oblique angle relative to the central longitudinal axis 212.

[0089] Figure 12 is a detailed view illustrating a portion of a medical stent 210 as described herein. Those skilled in the art will appreciate that the features between certain features have been exaggerated in order to illustrate their relationship, Figure 12 In the side view, the features are not shown in straight lines. Rather, a slight angle has been introduced into the view, allowing the features to be more easily seen and understood. In addition, one of the plurality of first filaments 230 is shown in shadow to make the filament and first helical path clear to the viewer, not intended to represent a cross-section.

[0090] As described herein, the medical stent 210 can include a plurality of first filaments 230 and a plurality of second filaments 240. At least one filament of the plurality of first filaments 230 can include a circumferential offset disposed between the first helically extending portion and the second helically extending portion. The circumferential offset can form a migration resistant ring 250. In at least some embodiments, the plurality of first filaments 230 can be interwoven with the plurality of second filaments 240, for example when forming a braid. Figure 12 An up-down-up pattern of interwoven filaments is illustrated. Other configurations and / or patterns are also contemplated.

[0091] In some embodiments, interweaving the plurality of first filaments 230 with the plurality of second filaments 240 defines a plurality of intersection points where the first filaments cross over and / or under the second filaments. The first helical path of at least one filament of the plurality of first filaments 230 can pass under a first one of the plurality of second filaments 240 at a first end of the circumferential offset and / or migration resistant ring 250, and can pass under a second one of the plurality of second filaments 240 at a second end of the circumferential offset and / or migration resistant ring 250. In at least some embodiments, the second one of the plurality of second filaments 240 can be adjacent to the first one of the plurality of second filaments 240. In this arrangement, at least one (e.g., Figure 12 the adjacent filaments) of the plurality of first filaments 230 can pass under both of the adjacent ones of the plurality of second filaments 240. This can be achieved by the circumferential offset and the migration resistant ring 250 extending radially outward from the outer surface of the body of the medical stent 210 between the two adjacent intersection points of the plurality of first filaments 230 and the plurality of second filaments 240.

[0092] In some embodiments, the first helical path of at least one filament of the plurality of first filaments 230 includes a plurality of circumferential offsets longitudinally spaced from one another between the first end and the second end. In some embodiments, at least one filament of the plurality of first filaments 230 can include a plurality of migration resistant rings 250 protruding radially outward from the outer surface of the body of the medical stent 210 at the plurality of circumferential offsets. For example, each circumferential offset can form a migration resistant ring 250, and a plurality of migration resistant rings 250 can be formed from and / or within a single one of the plurality of first filaments 230, as shown in Figure 12 .

[0093] In some embodiments, a plurality of anti-migration rings 250 protruding radially outward from the outer surface of the body of the medical stent 210 may form a plurality of circumferential rows of anti-migration rings 250 extending around the body of the medical stent 210. In some embodiments, the anti-migration rings 250 in a circumferential row may be axially and / or circumferentially aligned at a common axial position along the central longitudinal axis of the medical stent 210. The plurality of circumferential rows of anti-migration rings 250 may be longitudinally spaced from each other along the body of the medical stent 210.

[0094] In some embodiments, the medical stent 210 may be a covered stent. Therefore, the medical stent 210 may include a cover 260 disposed on and / or attached to a plurality of first filaments 230 and a plurality of second filaments 240. The cover 260 may span the gaps between adjacent filaments of the plurality of first filaments 230 and the plurality of second filaments 240. In at least some embodiments, the cover 260 may be impermeable to fluids, debris, and / or tissue ingrowth. In some embodiments, the cover 260 may extend along the body of the medical stent 210 from a first end to a second end. In some embodiments, the cover 260 may extend along the entire length of the medical stent 210. In some embodiments, the cover 260 may be disposed on the inner surface of the body, the outer surface of the body, or both the inner and outer surfaces of the body, or the body may be embedded within the cover 260, wherein the anti-migration ring 250 protrudes radially outward from the cover 260. Other configurations are also conceivable.

[0095] As mentioned above and in Figure 12 As shown, at least a portion of the anti-migration ring 250 may be oriented substantially perpendicular to the central longitudinal axis of the medical stent 210. In an alternative configuration, a portion of the anti-migration ring 250 may be tilted toward the second end. In some embodiments, only the radially outer portion (radial outer half or less) of the anti-migration ring 250 may be tilted toward the second end, while the radially inner portion (radial inner half or the remainder) of the anti-migration ring 250 may be oriented substantially perpendicular to the central longitudinal axis of the medical stent 210. In another alternative configuration, a portion of the anti-migration ring 250 may be tilted toward the first end. In some embodiments, only the radially outer portion (radial outer half or less) of the anti-migration ring 250 may be tilted toward the first end, while the radially inner portion (radial inner half or the remainder) of the anti-migration ring 250 may be oriented substantially perpendicular to the central longitudinal axis of the medical stent 210. Other configurations are also conceivable.

[0096] Those skilled in the art will recognize that the invention can be embodied in many forms different from the specific embodiments described and contemplated herein. Therefore, deviations in form and detail may be made without departing from the scope and spirit of the invention as described in the appended claims.

[0097] Materials that can be used for the various components and elements of the medical stents, mandrels, and their respective parts disclosed herein may include materials associated with the medical device and the mandrel. For simplicity, the following discussion refers to the device. However, this is not intended to limit the group of devices and methods disclosed herein, as the discussion can be applied to other elements, components, parts, or devices disclosed herein, such as, but not limited to: medical stents, mandrels, filaments, anti-migration rings, coverings, and / or their elements or parts.

[0098] In some embodiments, the device and / or its components may be made of metal, metal alloy, polymer (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, or other suitable materials.

[0099] Some examples of suitable polymers may include: polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), fluorinated ethylene-propylene copolymer (FEP), and polyoxymethylene (POM, for example, those available from DuPont). ), polyether ester block copolymers, polyurethanes (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether esters (e.g., those purchased from DSM Engineering Plastics). ), ether- or ester-based copolymers (e.g., polybutylene terephthalate and / or other polyester elastomers, such as those available from DuPont). ), polyamide (e.g., purchased from Bayer). Or purchased from Elf Atochem. ), elastic polyamides, block polyamides / ethers, polyether block amides (PEBA, for example, by trade name) Purchased), ethylene vinyl acetate copolymer (EVA), polysilicon, polyethylene (PE) High-density polyethylene, Low-density polyethylene, linear low-density polyethylene (e.g.) Polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene ether (PPO), poly(p-phenylene terephthalamide) (e.g., Polysulfone, nylon, nylon-12 (if available from EMS American Grilon) Perfluoropropyl vinyl ether (PFA), ethylene-vinyl alcohol copolymers, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), (styrene-b-isobutylene-b-styrene) triblock copolymers (e.g., SIBS and / or SIBS 50A), polycarbonates, polyurethane polysiloxane copolymers (e.g., those purchased from Aortech Biomaterias). Or purchased from AdvanSource Biomaterials. Biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, etc. In some embodiments, the sleeve may be mixed with a liquid crystal polymer (LCP). For example, the mixture may contain up to about 6% LCP.

[0100] Some examples of suitable metals and metal alloys include: stainless steels such as 304V, 304L, and 316LV stainless steels; mild steels; nickel-titanium alloys such as linearly elastic / or hyperelastic nickel-titanium alloys; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS:N06625). 625, UNS:N06022 UNS:N10276 other alloys, etc.), nickel-copper alloys (e.g., UNS:N04400, etc.). 400, Nickel 400 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, etc.) (etc.), nickel-molybdenum alloys (e.g., UNS:N10665, etc.) alloy 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 gold alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, etc.). (etc.); platinum-rich stainless steel; titanium; platinum; palladium; gold; combinations thereof; or any other suitable material.

[0101] In at least some embodiments, portions or all of the device and / or components thereof can also be doped with, made of, or otherwise incorporate radio-opaque materials. Radio-opaque materials are understood to be materials that are capable of producing a relatively bright image on a fluoroscope screen or another imaging technique during a medical procedure. This relatively bright image helps the user of the device to determine its location. Some examples of radio-opaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radio-opaque fillers, etc. In addition, other radio-opaque markers and / or coils can also be incorporated into the design of the device to achieve the same result.

[0102] In some embodiments, a degree of Magnetic Resonance Imaging (MRI) compatibility is imparted into the devices and / or other elements disclosed herein. For example, the device and / or components or portions thereof can be made of a material that does not significantly distort the image and create significant artifacts (e.g., gaps in the image). Certain ferromagnetic materials, for example, can be unsuitable because they can create artifacts in an MRI image. The device or portions thereof can also be made of a material that the nuclear magnetic resonance instrument can image. Some materials that exhibit these properties include, for example: tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as CONART® available from Koninklijke Philips N.V. of Eindhoven, Netherlands), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® available from SMPSS® available from SPS Metalkraft Przedsibiorstwo Spolka Jawna of Gliadel® available from GliaTech, Inc. of Alpharetta, Georgia, USA), nickel-titanium alloys such as linear-elastic or super-elastic alloys, e.g., linear-elastic and / or super-elastic Nitinol, cobalt-chromium alloys, cobalt-chromium- tungsten alloys, titanium alloys, platinum alloys, titanium platinum alloys, platinum

[0103] In some embodiments, the devices and / or other elements disclosed herein can include and / or be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents can include: antithrombogenic agents (e.g., heparin, heparin derivatives, urokinase, and PPack (dextrophenylalanine proline arginine chloromethylketone)); anti-proliferative agents (e.g., enoxaparin, angio statin, monoclonal antibody capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory agents (e.g., dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and salicylic acid); antitumor / anti-proliferative / anti-mitotic agents (e.g., paclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin and thymidine kinase inhibitors); anesthetics (e.g., lidocaine, bupivacaine, and ropivacaine); anti-coagulants (e.g., D-Phe-Pro-Arg chloromethylketone, an RGD peptide as described by Samanen et al. (1997) J. Pharmacol. Exp. Ther. 283: 1 143- 1156, heparin, anti-thrombin antibodies, anti-thrombotic antibodies, anti-platelet receptor antibodies, anti-coagulants, anti-platelet drugs, and snake venom); vascular cell growth promoters (e.g., growth factor inhibitors, growth factor receptor antagonists, transcriptional activators, and translational promoters); vascular cell growth inhibitors (e.g., growth factor inhibitors, growth factor receptor antagonists, transcriptional repressors, translational repressors, replication inhibitors, inhibitory antibodies, antibodies directed 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; vasodilating agents; and agents which interfere with endogenous vascoactive mechanisms.

[0104] It is to be understood that the present disclosure is merely illustrative in many respects. Changes can be made in the details, especially in matters of shape, size, and arrangement of steps, without exceeding the scope of the application. This can include using any feature of one exemplary embodiment with other embodiments, to the extent appropriate. The scope of the application is defined by the language of the claims that follow.

Claims

1. A medical stent having a first end, a second end, and a central longitudinal axis extending from the first end to the second end, comprising: a plurality of first filaments each extending in a first helical path around the central longitudinal axis in a first direction; and a plurality of second filaments each extending in a second helical path around the central longitudinal axis in a second direction; wherein the plurality of first filaments are interwoven with the plurality of second filaments; wherein the first helical path of at least one filament of the plurality of first filaments includes a circumferential offset disposed between the first end and the second end, wherein the circumferential offset forms an anti-migration ring that protrudes radially outward from an outer surface of the medical stent, and at least a portion of the anti-migration ring is oriented substantially perpendicular to the central longitudinal axis, and wherein a portion of the anti-migration ring is angled toward the first end or the second end of the medical stent.

2. The medical stent of claim 1, wherein interweaving the plurality of first filaments with the plurality of second filaments defines a plurality of intersection points.

3. The medical stent of claim 2, wherein the first helical path of the at least one filament of the plurality of first filaments passes under a first one of the plurality of second filaments at a first end of the circumferential offset and passes under a second one of the plurality of second filaments at a second end of the circumferential offset.

4. The medical stent of claim 1, wherein the first helical path of the at least one filament of the plurality of first filaments has a plurality of circumferential offsets longitudinally spaced from one another between the first end and the second end.

5. The medical stent of claim 1, wherein the first helical path of some of the plurality of first filaments each has a circumferential offset disposed between the first end and the second end.

6. A mandrel for forming a medical stent, comprising: a cylindrical body; and a plurality of protrusions extending radially outward from the cylindrical body; wherein the plurality of protrusions define a plurality of first channels extending helically around the cylindrical body in a first direction and a plurality of second channels extending helically around the cylindrical body in a second direction; wherein at least some of the plurality of protrusions have a groove formed therein extending in a circumferential direction along the cylindrical body, and wherein the groove is oriented substantially perpendicular to a central longitudinal axis of the cylindrical body.

7. The mandrel of claim 6, wherein the at least some of the plurality of protrusions having a groove formed therein are raised protrusions extending further radially outward from the cylindrical body than the remainder of the plurality of protrusions.

8. The mandrel of any one of claims 6-7, wherein the groove communicates adjacent ones of the plurality of first channels.

9. The mandrel of any one of claims 6-7, wherein at least some of the plurality of protrusions having a groove formed therein form a circumferential row of protrusions extending around the cylindrical body.

10. A method of manufacturing a medical stent, comprising: using a mandrel comprising a cylindrical body and a plurality of protrusions extending radially outward from the cylindrical body, wherein the plurality of protrusions define a plurality of first channels extending helically around the cylindrical body in a first direction and a plurality of second channels extending helically around the cylindrical body in a second direction, wherein at least some of the plurality of protrusions have a groove formed therein extending in a circumferential direction along the cylindrical body; and winding a plurality of first filaments around the mandrel within the plurality of first channels and winding a plurality of second filaments around the mandrel within the plurality of second channels such that the plurality of first filaments are interwoven with the plurality of second filaments to define a body of the medical stent; wherein at least some of the plurality of first filaments are wound on the at least some of the plurality of protrusions having the groove formed therein and extend through the groove in the at least some of the protrusions.

Images