Stent including anti-migration member

Abstract

Exemplary expandable stent designs are disclosed. One example of an expandable stent includes a tubular scaffold including an inner surface, an outer surface, and a lumen extending therethrough. The expandable stent also includes an outer layer disposed along the outer surface of the tubular scaffold and a first preformed flap attached to the outer layer. Further, the preformed flap is configured to releasably engage a vessel wall when the stent is embedded in the vessel wall.

Description

[Technical field]

[0001] The present disclosure relates to medical devices, methods of making medical devices, and uses thereof. More particularly, the present disclosure relates to stents including anti-migration members, and methods of making and using such stents. [Background technology]

[0002] Implantable medical devices (e.g., expandable stents) may be designed to provide a pathway for the flow of digested material, blood, or other fluids following a medical procedure. Additionally, some implantable medical devices may incorporate features to aid in fistula repair, bypass surgery, and / or anastomosis repair. These medical devices may include radial or self-expanding stents that are implanted transluminally via an endoscope. Additionally, some stents may be implanted in various body lumens, such as the esophageal tract, digestive tract (including the intestine, stomach, and colon), tracheobronchial tract, urinary tract, biliary tract, and vasculature.

[0003] In some cases, it may be desirable to design a stent with sufficient radial strength to maintain its position within a body lumen while at the same time having the ability to act as a passageway for food and other ingested materials to pass through. However, the compressibility and flexibility properties of some stents that aid in their placement may also cause the stent to migrate from its original deployed position. For example, a stent designed to be placed within the esophagus or gastrointestinal tract may migrate due to peristalsis (i.e., the involuntary contraction and relaxation of the muscles of the esophagus, intestine, and colon that push the contents of the tract). Additionally, the moist and naturally lubricating environments of the esophagus, intestine, colon, etc., further contribute to the tendency of a stent to migrate when deployed within them. However, while it is important to design a stent to reduce the degree to which the stent migrates within a body lumen, it is also important to design a stent that can be easily removed and / or repositioned from the body lumen after deployment.

[0004] Therefore, it may be desirable to design a stent that includes anti-migration structures to reduce the ability of the stent to migrate within the anatomy.Disclosed herein are examples of medical devices that include flexible anchor members. Summary of the Invention

[0005] This disclosure provides design, material, manufacturing, and use alternatives for medical devices. One example of an expandable stent includes a tubular scaffold including an inner surface, an outer surface, and an interiorly extending lumen. The expandable stent also includes an outer layer disposed along the outer surface of the tubular scaffold and a first preformed flap attached to the outer layer. Further, the preformed flap is configured to releasably engage a vessel wall when the stent is embedded in the vessel wall.

[0006] Alternatively or additionally to any of the above embodiments, the first preformed flap is configured to rotate between a radially extended position and a folded position.

[0007] Alternatively or additionally to any of the above embodiments, the first pre-formed flap is configured to redirect radially inward from a radially extended position. Alternatively or in addition to any of the above embodiments, the first preformed flap includes a first attachment area disposed along a first edge of the flap, and the first preformed flap is attached to the outer layer along the first attachment area.

[0008] Alternatively or additionally to any of the above embodiments, the first preformed flap is bonded to the outer layer using a bonding material. Alternatively or additionally to any of the above embodiments, the outer layer, the first preformed flap, and the bonding material are formed from the same material.

[0009] Alternatively or additionally to any of the above embodiments, further comprising a second preformed flap, said first preformed flap and said second preformed flap being evenly spaced around said tubular scaffold.

[0010] Alternatively or additionally to any of the above embodiments, the first preformed flap and the second preformed flap are longitudinally aligned with each other along the outer layer of the stent.

[0011] Alternatively or additionally to any of the above embodiments, the first preformed flap and the second preformed flap are longitudinally offset from one another along the outer layer of the stent.

[0012] Alternatively or additionally to any of the above embodiments, the first pre-formed flap is disposed along a proximal end region of the tubular scaffold and the second pre-formed flap is disposed along a distal end region of the tubular scaffold.

[0013] Alternatively or additionally to any of the above embodiments, the first preformed flap extends distally toward a distal end of the tubular scaffold and the second preformed flap extends proximally toward a proximal end of the tubular scaffold.

[0014] Alternatively or additionally to any of the above embodiments, further including a second preformed flap attached to the outer layer of the stent, a third preformed flap attached to the outer layer of the stent, and a fourth preformed flap attached to the outer layer of the stent, wherein the first preformed flap, the second preformed flap, the third preformed flap, and the fourth preformed flap are helically disposed around the tubular scaffold.

[0015] Another example stent includes a tubular scaffold having an inner surface, an outer surface, and a lumen extending therethrough. The stent also includes an outer layer disposed along the outer surface of the tubular scaffold and a plurality of preformed flaps formed separately from and attached to the outer layer, each of the preformed flaps configured to rotate between a radially extending position and a collapsed position. Further, each of the plurality of preformed flaps is configured to releasably engage a vessel wall when the stent is embedded therein.

[0016] Alternatively or additionally to any of the above embodiments, each of the plurality of preformed flaps is configured to deflect radially inwardly from a radially extended position.

[0017] Alternatively or additionally to any of the above embodiments, each of the plurality of preformed flaps is bonded to the outer layer using a bonding material. Alternatively or additionally to any of the above embodiments, the outer layer, the plurality of preformed flaps, and the bonding material are formed from the same material.

[0018] Alternatively or additionally to any of the above embodiments, the plurality of pre-formed flaps are uniformly spaced around a circumference of the tubular scaffold. Alternatively or additionally to any of the above embodiments, a plurality of pre-formed flaps are aligned longitudinally along said tubular scaffold.

[0019] Alternatively or additionally to any of the above embodiments, the plurality of pre-formed flaps are arranged helically around the tubular scaffold. Another example stent includes an expandable tubular scaffold having an outer surface and an opposing inner surface, the tubular scaffold including a first end region, a second end region, and an intermediate region located between the first end region and the second end region. The stent also includes an outer layer disposed along the outer surface of the tubular scaffold and a plurality of preformed flaps attached to and extending outwardly therefrom, each of the preformed flaps configured to rotate between a radially extended position and a collapsed position.

[0020] Further, a first preformed flap of the plurality of flaps is disposed along the first end region and a second flap of the plurality of flaps is disposed along the second end region, and each of the plurality of preformed flaps is configured to releasably engage a vessel wall when the stent is implanted within the vessel wall.

[0021] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The following figures and detailed description more particularly exemplify these embodiments. [Brief description of the drawings]

[0022] The present disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: [Figure 1A] 1 illustrates an exemplary stent having anti-migration flaps in an extended configuration. [Figure 1B] 1 illustrates an exemplary anti-migration flap. [Figure 1C] 1B illustrates the exemplary stent of FIG. 1A with anti-migration flaps redirected radially inward. [Diagram 2] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Diagram 3] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Figure 4] FIG. 4 is a top view of the exemplary stent shown in FIG. [Figure 5A] 1 illustrates an exemplary flexible anti-migration flap. [Figure 5B] 1 illustrates another exemplary flexible anti-migration flap. [Figure 5C] 1 illustrates another exemplary flexible anti-migration flap. [Figure 5D] 1 illustrates another exemplary flexible anti-migration flap. [Figure 6] FIG. 13 is a top view of another exemplary stent with flexible anti-migration flaps. [Figure 7] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Figure 8] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Figure 9] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Figure 10A] FIG. 10A is a cross-sectional view taken along line 10A-10A in FIG. [Figure 10B] FIG. 10B is a cross-sectional view taken along line 10B-10B in FIG. [Figure 11] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Figure 12] Flexible anti-migration flap ring. [Figure 13] 13 illustrates an exemplary stent with anti-migration flap rings as shown in FIG. 12. [Figure 14] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Figure 15] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Figure 16] 1 illustrates another exemplary stent with flexible anti-migration flaps. [Figure 17] 1 illustrates another exemplary stent with flexible anti-migration flaps. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The disclosure is susceptible to various modifications and alternative forms, details of which have been shown by way of example in the drawings and will be described in detail, however, it is to be understood that there is no intention to limit the disclosure to the particular embodiments described, but rather the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

[0024] Detailed Description For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification.

[0025] All numerical values ​​herein are deemed to be modified by the term "about", whether or not expressly stated. The term "about" generally refers to a range of numerical values ​​that one of ordinary skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the term "about" may include a range of numerical values ​​that are rounded to the nearest significant figure.

[0026] The recitation of numerical ranges by upper and lower limits includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). As used in this specification and the appended claims, the singular forms "a," "an," "the," and "said" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in its sense including "and / or" unless the content clearly dictates otherwise.

[0027] It should be noted that when a reference is made herein to "one embodiment," "some embodiments," "other embodiments," etc., this reference indicates that the described embodiment may include one or more particular features, structures, and / or characteristics. However, such a reference does not necessarily mean that all embodiments include that particular feature, structure, and / or characteristic. Furthermore, when a particular feature, structure, and / or characteristic is described in connection with one embodiment, it should be understood that such feature, structure, and / or characteristic may also be used in connection with other embodiments, whether or not expressly stated, unless specifically stated to the contrary.

[0028] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same, and in which the drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure.

[0029] One possibility for reducing stent migration while at the same time allowing for removal or repositioning of the stent after deployment is to attach one or more flexible anchoring members to the outer surface of the stent, which releasably secure the stent in place by engaging the vessel wall, reducing the risk of stent migration. Furthermore, the flexible anchoring members can be easily removed and / or repositioned from the body lumen after deployment. Examples of medical devices, such as stents, that include flexible anchoring members are disclosed herein.

[0030] 1A illustrates an exemplary stent 10. Stent 10 may have a first end 16, a second end 18, and a lumen extending therethrough. When placed within a body lumen (e.g., the esophagus), the first end, or proximal end 16, may be defined as the end of stent 10 closest to the patient's mouth, and the second end, or distal end 18, may be defined as the end of stent 10 closest to the patient's stomach.

[0031] Additionally, the stent 10 may include one or more stent strut members 12 that form a tubular scaffold. The stent strut members 12 may extend helically, longitudinally, circumferentially, or in other directions along the stent 10. Although Figure 1A shows the stent strut members 12 extending along the entire length of the stent 10, in other examples, the stent strut members 12 may extend only along a portion of the stent 10.

[0032] 1A illustrates that in some instances, stent 10 can include a first flare region 20 proximate first end 16 and / or a second flare region 22 proximate second end 18 of stent 10. In some cases, first flare region 20 and second flare region 22 can be defined as an increase in the outer diameter, inner diameter, or both the inner and outer diameters along one or both of first end 16 and / or second end 18 of stent 10. Additionally, FIG. 1A illustrates stent 10 including an intermediate region 24 located between first flare region 20 and second flare region 22.

[0033] However, while FIG. 1A shows stent 10 including both first and second flare regions 20 and 22, it is contemplated that stent 10 may include only one flare region. For example, it is contemplated that stent 10 may include only flare region 20 or only flare region 22. It is further contemplated that all or a portion of first flare region 20 and / or second flare region 22 may extend outward (e.g., away from the central longitudinal axis of stent 10). It is further contemplated that all or a portion of first flare region 20 and / or second flare region 22 may extend inward (e.g., toward the central longitudinal axis of stent 10). In yet other examples, it is contemplated that stent 10 may not include a flare region. For example, stent 10 may have a uniform diameter along its entire length.

[0034] In some cases, the stent 10 may be a self-expanding stent, or the stent 10 may be a balloon-expandable stent. Examples of self-expanding stents include stents having a tubular scaffold configuration of one or more filaments or struts 12 that are combined to form a rigid and / or semi-rigid stent structure. For example, the stent filaments 12 may be wires or other filaments that are braided, wrapped, entangled, interwoven, woven, braided, looped (e.g., bobbinette style), etc. to form a tubular scaffold. For example, the exemplary stents disclosed herein may resemble braided stents, although this is not intended to limit possible stent configurations. Rather, the stents depicted in the figures may be stents that include one or more or a plurality of filaments that are braided, braided, wrapped, entangled, interwoven, woven, braided, looped (e.g., bobbinette style), etc. to form a tubular scaffold. Alternatively, stent 10 may be a monolithic structure formed from a cylindrical tubular member, such as a Nitinol tubular member where a single cylindrical tube is laser cut with the remaining portions of the tubular member forming the stent struts 12. Openings or gaps through the wall of stent 10 may be defined between adjacent stent struts 12.

[0035] Stent 10 in some examples disclosed herein may be constructed from a variety of materials. For example, stent 10 (e.g., self-expanding or balloon-expandable) may be constructed from a metal (e.g., Nitinol, Elgiloy, etc.). In other examples, stent 10 may be constructed from a polymeric material (e.g., PET). In yet other examples, stent 10 may be constructed from a combination of metallic and polymeric materials. Additionally, stent 10 may include bioabsorbable and / or biodegradable materials.

[0036] In some cases, the exemplary stent 10 may include one or more layers disposed on and / or adjacent to the inner and / or outer surface of the tubular scaffold of the stent 10. For example, FIG. 1A illustrates an exemplary stent 10 including an outer layer 14 (shown in FIG. 1A as a dot pattern) or covering disposed along a portion of the outer surface of the tubular scaffold of the stent 10, thereby defining the outer surface of the stent 10. In some cases, the outer layer 14 may be an elastomeric or non-elastomeric material. For example, the outer layer 14 may be a polymeric material such as silicone, polyurethane, or the like. The outer layer 14 (e.g., coating or covering) may be non-porous and seamless along the entire length of the tubular scaffold and may extend continuously around the tubular scaffold to prevent tissue in-growth into the central lumen of the stent 10.

[0037] As discussed herein, stents designed to be placed in a body lumen (e.g., the esophagus or gastrointestinal tract) may migrate due to peristaltic movement and / or the typically moist and inherently lubricious environment of the body lumen. Thus, one method of reducing stent migration includes removably attaching one or more flexible anchor members (e.g., flexible flaps) to the outer surface of the stent scaffold. The flexible anchor members may provide a structure that engages the vessel wall to reduce the risk of stent migration.

[0038] 1A shows one or more flexible anchor members 26 disposed on the outer surface of stent 10. The one or more anchor members 26 may extend radially outward from the outer surface of stent 10 to engage the wall of a body lumen in which stent 10 is deployed. Additionally, the one or more anchor members 26 may be designed to prevent shifting or migration of stent 10 relative to the body lumen in which it is implanted.

[0039] In some examples, one or more flexible anchor members 26 shown in FIG. 1A can be considered flexible "flaps" that provide anti-migration functionality by being attached to the outer surface of the stent 10. Thus, the term "flap" can be synonymous with the term "anchor member" as used herein. Additionally, one or more flexible anchor members 26 can be constructed as separate components from the stent filaments or struts 12 and outer layer 14 that form the tubular scaffold, such that one or more anchor members 26 can be formed separately from the outer surface of the stent 10 in a manufacturing step after construction of the scaffold 12 and outer layer 14, and then attached to the outer surface of the stent 10 (e.g., attached to the outer surface of the outer layer 14). In other words, the flexible anchor members 26 can be "preformed" separately from the stent struts 12 and outer layer 14. For purposes of the discussion herein, a preformed anchor member 26 refers to an anchor member 26 (e.g., a flap) that is formed (e.g., manufactured, constructed, etc.) separate from the stent 10 and separate from the outer layer 14 (e.g., a coating or covering), and then attached to the outer surface of the stent 10 (e.g., attached to the outer layer 14) in a separate manufacturing step following construction of the anchor member 26, scaffolding 12 and outer layer 14.

[0040] Additionally, one or more anchor members 26 may be formed separately from the outer surface of stent 10 (e.g., outer layer 14) and then attached to the outer surface of stent 10 (e.g., outer layer 14) along a pivot region of each anchor member 26. The pivot region of each anchor member 26 may be defined as the portion of the preformed anchor member 26 about which the anchor member 26 rotates, turns, or bends. In other words, each of the preformed anchor members 26 is attached to the outer surface of stent 10 along the pivot region of each anchor member 26, thereby allowing each anchor member 26 to pivot, turn, or bend relative to the outer surface of stent 10 at the pivot region.

[0041] As described herein, anchor member 26 can be considered a "flap." A flap as defined herein can include a generally flat, wide structure attached to the outer surface of the stent along only one of its sides (e.g., edges). Furthermore, in some examples, the flaps described herein can hang loosely along the outer surface of the stent 10 and can rotate, redirect, or bend along an edge of the flap (e.g., a pivot region) that is attached to the outer surface of the stent 10.

[0042] FIG. 1B illustrates an exemplary anchor member 26. FIG. 1B illustrates that the anchor member 26 can include a first end 28 and a second end 30. Additionally, as described herein, the anchor member 26 can include a pivot region 32 extending along the width of the first end 28 of the anchor member 26. The pivot region 32 can define a portion of the anchor member 26 that is directly attached to the outer surface of the stent 10. The remaining portion of the anchor member 26 may not be attached to the outer surface of the stent 10, and the anchor member 26 is attached to the outer surface of the stent 10 only by the pivot region 32 along one edge of the anchor member 26. Thus, the second end 30 can be considered a free end of the anchor member 26 that can move radially toward or away from the outer surface of the stent 10 as the anchor member rotates, turns, or bends along the pivot region 32.

[0043] FIG. 1B further illustrates that anchor member 26 can include a length "X" representing the distance the flap extends radially outward from the outer surface of stent 10 when fully extended. Length "X" can represent the distance between pivot region 32 along base or first end 28 of the flap and the free end of second end 30 of the flap. The length of anchor member 26 (the distance the anchor member extends from outer layer 14 when fully extended) can be, for example, about 0.5 mm to 16 mm, or about 1 mm to 14 mm, or about 1.5 mm to 12 mm, or about 2 mm to 10 mm, or about 3 mm to 8 mm, or about 4 mm to 6 mm. FIG. 1B further illustrates that anchor member 26 can include a width "Y" representing the width of anchor member 26 measured along a line substantially perpendicular to length X. The width Y of the anchor member 26 can be, for example, about 1 mm to 8 mm, or about 1.5 mm to 7 mm, or about 2 mm to 6 mm, or about 3 mm to 5 mm. Furthermore, FIG. 1B shows that the anchor member 26 can include a thickness "Z". The thickness Z can be about 5 to 120 μm, about 10 to 110 μm, 20 to 100 μm, 30 to 90 μm, or about 40 to 80 μm. Thus, the thickness Z can be substantially less than the length and width of the anchor member 26. For example, the length W and / or the width W can be at least 50 times or more, 100 times or more, 150 times or more, 200 times or more, 300 times or more than the thickness Z. Furthermore, FIG. 1B shows that the upper and lower surfaces of the anchor member 26 can include a surface area 34. The surface area 34 can be, for example, about 0.5 mm. 2 ~128mm 2 , about 5mm 2 ~110mm 2 , about 15mm 2 ~90mm 2 , about 25mm 2 ~70mm 2 , or about 35 mm 2 ~50mm 2 It could be.

[0044] In some examples, the one or more anchor members 26 may be comprised of the same material as the outer layer 14. For example, both the one or more anchor members 26 and the outer layer 14 may include silicone or other biocompatible polymeric materials. Examples of suitable materials that may be used to comprise the one or more anchor members 26 are provided herein. Additionally, the one or more anchor members 26 may be bonded (e.g., secured, attached, connected, secured, etc.) to the outer layer 14 and / or stent struts 12 using a bonding material comprised of the same material used to construct both the one or more anchor members 26 and / or the outer layer 14. However, in other examples, the one or more anchor members 26, stent struts 12, and / or outer layer 14 may be comprised of different materials. Additionally, in some examples, the material used to bond the one or more anchor members 26 to the outer surface of the stent 10 may be different than the material used to construct the one or more anchor members 26, stent struts 12, and / or outer layer 14.

[0045] 1A illustrates that one or more anchor members 26 may be disposed along the proximal end region 16 of the stent 10. For example, FIG. 1A illustrates anchor members 26 disposed along the flared region 20 of the stent 10. It is envisioned that anchor members 26 may be disposed along any portion of the flared region 20.

[0046] 1A further illustrates that one or more anchor members 26 may be spaced apart about the exterior surface of stent 10. In some cases, one or more anchor members 26 may be uniformly spaced apart about the exterior surface of stent 10. However, in other cases, one or more anchor members 26 may be non-uniformly spaced apart about the exterior surface of stent 10.

[0047] It is further contemplated that one or more anchor members 26 of stent 10 may extend radially outward from stent 10 at various angles, directions, etc. For example, FIG. 1A illustrates anchor members 26 disposed on flared region 20 and directed toward distal end 18 of stent 10. However, it is contemplated that in some cases, one or more anchor members 26 may be directed toward proximal end 16 of stent 10. In yet other instances, it is contemplated that stent 10 may include one or more anchor members 26 directed toward proximal end 16 of stent 10 and one or more anchor members 26 directed toward distal end 18 of stent 10. Furthermore, although FIG. 1A illustrates stent 10 including three anchor members 26, it is contemplated that stent 10 may include 1, 2, 3, 4, 5, 6, 7, 8, or more anchor members 26.

[0048] 1C illustrates an exemplary stent 10 in which one or more anchor members 26 are redirected (e.g., collapsed, flattened, flexed, rotated, etc.) radially inward and disposed substantially flat against the outer surface of the stent 10. In the configuration illustrated in FIG. 2, it can be seen that the anchor members 26 disengage from the vessel wall, thereby allowing the stent 10 to be removed from and repositioned within the vessel. As illustrated in FIG. 2, the anchor members 26 can remain attached to the outer surface of the stent 10 as they are redirected radially inward (towards the outer surface of the stent 10). The anchor members 26 can rotate (e.g., hinge-like) along the bond region where the anchor members 26 are attached to the outer surface of the stent 10.

[0049] Additionally, the ability of anchor members 26 to redirect radially inwardly can be beneficial when loading stent 10 into a stent delivery system. It is understood that the stent delivery system can include a delivery catheter having a lumen designed to accommodate stent 10. For delivery purposes, the delivery catheter is often designed to have a minimal outer diameter, and therefore it can be beneficial to design stent 10 to radially collapse to a diameter required to fit within the lumen of the delivery catheter. Thus, the ability of anchor members 26 to collapse flat against the outer surface of stent 10 is beneficial in allowing stent 10 to radially collapse into a delivery configuration.

[0050] 2 illustrates another exemplary stent 110. Stent 110 may be similar in form and function to other stents disclosed herein. Stent 110 may include a proximal end 116, a distal end 118, stent struts 112, an outer layer 114, and anchor members 126 disposed along the distal end region 118.

[0051] 2 further illustrates that one or more anchor members 128 can be disposed along the distal end region 118 of the stent 110. For example, FIG. 2 illustrates anchor members 128 disposed along the flared region 122 of the stent 110. It is also envisioned that anchor members 128 may be disposed along any portion of the flared region 122.

[0052] 2 further illustrates that one or more anchor members 128 may be spaced circumferentially about the outer surface of stent 110. In some cases, one or more anchor members 128 may be evenly spaced about the outer surface of stent 110. However, in other cases, one or more anchor members 128 may be unevenly spaced about the outer surface of stent 110.

[0053] It is further contemplated that one or more anchor members 128 of stent 110 may extend radially outward from stent 110 at various angles, directions, etc. For example, FIG. 2 illustrates anchor members 128 disposed on flared region 122 directed toward proximal end 116 of stent 110. However, it is contemplated that in some cases, one or more anchor members 128 may be directed toward distal end 118 of stent 110. In yet other examples, it is contemplated that stent 10 may include one or more anchor members 128 directed toward proximal end 116 of stent 110, and one or more of anchor members 128 may be directed toward distal end 118 of stent 110. Additionally, although FIG. 2 illustrates stent 110 including three anchor members 126, it is contemplated that stent 110 may include 1, 2, 3, 4, 5, 6, 7, 8, or more anchor members 126.

[0054] 3 illustrates another exemplary stent 210. Stent 210 may be similar in form and function to other stents disclosed herein. Stent 210 may include a proximal end 216, a distal end 218, stent struts 212, an outer layer 214, anchor members 226 disposed along a flared region 220 of distal end region 218, and anchor members 228 disposed along a flared region 222 of distal end region 218.

[0055] 3 further illustrates that stent 210 may further include one or more anchor members 230 disposed along intermediate region 224 of stent 210. Anchor member 230 may be disposed distal to anchor member 226. Anchor member 230 may extend radially outward from stent 210 at various angles, directions, etc. For example, FIG. 3 illustrates anchor member 230 disposed on intermediate region 224 and directed toward distal end 218 of stent 210. However, it is also envisioned that anchor member 230 may be directed toward proximal end 216 of stent 210.

[0056] 3 further illustrates that one or more anchor members 230 may be spaced circumferentially around the outer surface of stent 210. In some cases, one or more anchor members 230 may be evenly spaced around the outer surface of stent 210. However, in other cases, one or more anchor members 230 may be non-uniformly spaced around the outer surface of stent 210.

[0057] 3 further illustrates that stent 210 may further include one or more anchor members 232 disposed along intermediate region 224 of stent 210. Anchor member 232 may be disposed proximal to anchor member 228. Anchor member 232 may extend radially outward from stent 210 at various angles, directions, etc. For example, FIG. 3 illustrates anchor member 232 disposed on intermediate region 224 and directed toward proximal end 216 of stent 210. However, it is also envisioned that anchor member 232 may be directed toward distal end 218 of stent 210.

[0058] 3 further illustrates that one or more anchor members 232 may be circumferentially spaced about the outer surface of stent 210. In some cases, one or more anchor members 232 may be uniformly spaced about the outer surface of stent 210. However, in other cases, one or more anchor members 232 may be non-uniformly spaced about the outer surface of stent 210.

[0059] It is contemplated that various combinations of anchor members 226, 228, 230, 232 may be directed at the proximal end 216 and distal end 218 of the stent 210. For example, one or more of anchor members 226, 228, 230, 232 may be directed at the proximal end 216 of the stent 210 and one or more of anchor members 226, 228, 230, 232 may be directed at the distal end 218 of the stent 210. Additionally, although FIGURE 3 illustrates stent 210 including twelve anchor members 226, it is contemplated that stent 210 may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more anchor members 226.

[0060] Figure 4 illustrates a top view of stent 210. Specifically, Figure 4 illustrates that anchor members 226 can extend radially outward from the outer surface of stent 210. Additionally, Figure 4 illustrates that anchor members 226 can be uniformly spaced around the outer surface of stent 210. Although Figure 4 illustrates anchor member 226, anchor members 228, 230, 232 can also extend radially outward from the outer surface of stent 210 and be uniformly spaced around the outer surface of stent 210 (similar to anchor member 226).

[0061] Further, FIG. 4 illustrates that any of the anchor members described herein may include a variety of shapes. For example, FIG. 4 illustrates that anchor member 226 may include a generally ear-shaped flap extending outward from the outer surface of stent 210. Further exemplary shapes of flexible anchor members are illustrated in FIGS. 5A-5D. For example, FIG. 5A illustrates an exemplary stent 310 including an exemplary anchor member 326a having a generally triangular shape extending radially outward from the outer surface of stent 310 (the exemplary stent 310 may be similar in shape and function to other stents disclosed herein). FIG. 5B illustrates an exemplary anchor member 326b including a generally rectangular shape extending radially outward from the outer surface of exemplary stent 310. FIG. 5C illustrates an exemplary anchor member 326c including a generally circular shape extending radially outward from the outer surface of exemplary stent 310. FIG. 5D illustrates an exemplary anchor member 326 d that includes a generally irregular, asymmetric shape extending radially outward from the outer surface of the exemplary stent 310 .

[0062] Additionally, FIG. 6 illustrates a top view of another exemplary stent 410 that may be similar in shape and function to other stents disclosed herein. FIG. 6 illustrates that the exemplary stent 410 may include one or more "comb-like" or "fringe-like" anchor members 426 disposed about the periphery of the outer surface of the stent 410. FIG. 6 illustrates that the anchor members 426 may resemble a plurality of thin, tooth-like projections or strips (e.g., resembling the teeth of a comb) that extend radially outward from the outer surface of the stent 410. Additionally, FIG. 6 illustrates that the anchor members 426 may be discontinuous and spaced apart in discrete groups 434 along the circumference of the outer surface of the stent 410. However, it is contemplated that in some instances, the anchor members 426 may extend continuously along the circumference of the outer surface of the stent 410. In other words, in some examples, the stent 410 may not include multiple anchor member groups 434 , but rather, a comb-like or fringe-like anchor members 426 may extend circumferentially and continuously around the outer surface of the stent 410 .

[0063] It will be appreciated that in some cases, the anchor members 426 may be formed as separate components (e.g., comb-like or fringe-like structures) that are attached to the outer surface of the stent 410 in a manufacturing step separate from the construction of the scaffold 412 and the application of the outer layer 414 to the scaffold 412.

[0064] 7 illustrates another exemplary stent 510. The stent 510 may be similar in form and function to other stents disclosed herein. The stent 510 may include a proximal end region 516, a distal end region 518, stent struts 512, and an outer layer 514.

[0065] 7 further illustrates that stent 510 may include anchor members 526, 528 disposed along the proximal end region 516 of stent 510. However, FIG. 7 illustrates that anchor member 526 may be longitudinally offset from anchor member 528. In other words, anchor member 526 may be disposed closer to the proximal end of stent 510 as compared to anchor member 528. In some examples, anchor member 526 may be disposed along the flared region of stent 510 and anchor member 528 may be disposed along the mid-region of stent 510.

[0066] 7 further illustrates that stent 510 may include anchor members 530, 532 disposed along a distal end region 518 of stent 510. However, FIG. 7 illustrates that anchor member 530 may be longitudinally offset from anchor member 532. For example, anchor member 530 may be disposed closer to the distal end of stent 510 as compared to anchor member 532. In some examples, anchor member 530 may be disposed along a flared region of stent 510 and anchor member 532 may be disposed along a mid-region of stent 510.

[0067] The anchor members 526, 528 can extend radially outward from the stent 510 at various angles, directions, etc. For example, Figure 7 shows the anchor members 526, 528 oriented toward the distal end 518 of the stent 510. However, it is also envisioned that the anchor members 528, 526 can be oriented toward the proximal end 516 of the stent 510.

[0068] The anchor members 530, 532 can extend radially outward from the stent 510 at various angles, directions, etc. For example, Figure 7 shows the anchor members 530, 532 oriented toward the proximal end 516 of the stent 510. However, it is also envisioned that the anchor members 530, 532 can be oriented toward the distal end 518 of the stent 510.

[0069] 8 illustrates another exemplary stent 610. The stent 610 may be similar in form and function to other stents disclosed herein. The stent 610 may include a proximal end region 616, a distal end region 616, stent struts 616, and an outer layer 614.

[0070] FIG. 8 further illustrates that the stent 610 may include one or more anchor members 636 coupled to a helical base member 640 (e.g., helical ridges). The base member 640 is typically attached to the outer surface of the stent 610 (e.g., attached to the outer layer 614). Additionally, as shown in FIG. 8, the base member 640 may be helically wrapped around the outer surface of the stent 610. In some examples, the anchor members 636 may form a monolithic structure with the base member 640. In other words, the anchor members 636 may be composed of the same material as the base member 640. Additionally, in some examples, the anchor members 636 may be cut from the base member 640 (e.g., a portion of the base member 640 may be cut in the shape of the anchor member 636 and pulled radially away from the base member 640 to form a flap as shown in FIG. 8). However, in other examples, the anchor members 636 are formed independently of the base member 640 and attached in a subsequent manufacturing step.

[0071] It can be seen from FIG. 8 that the anchor members 636 can be positioned (e.g., attached) along any portion of the base member 640. For example, FIG. 8 shows that the anchor members 636 can be evenly positioned along the base member 640. For example, in the configuration shown in FIG. 8, the anchor members 636 are evenly spaced circumferentially but offset from one another longitudinally. However, in other examples, the anchor members 636 can be non-uniformly positioned (e.g., attached) along the base member 640. When non-uniformly positioned along the base member 640, it can be seen that the anchor members 636 can be offset from one another both circumferentially and longitudinally.

[0072] It is further envisioned that the base member 640 is constructed from the same materials as the outer layer 614. The base member 640 may be bonded to the outer layer using a variety of materials, including the same materials used to construct the outer layer 614.

[0073] 9 illustrates another exemplary stent 710. The stent 710 may be similar in form and function to other stents disclosed herein. The stent 710 may include a proximal end region 716, a distal end region 718, stent struts 712, an outer layer 714, and anchor members 726 disposed along the distal end region 718.

[0074] Figure 9 shows that stent 710 may further include anchor member 728, anchor member 730, and anchor member 732 attached to an outer surface of stent 710. From Figure 9, it can be seen that anchor member 728, anchor member 730, and anchor member 732 may be spaced apart from one another along a longitudinal axis of stent 710. Figure 9 further shows that anchor member 728, anchor member 730, and anchor member 732 may be radially aligned with one another along the circumference of stent 710.

[0075] The anchor members 726, 728, 730, 732 can extend radially outward from the stent 710 at various angles, directions, etc. For example, Figure 9 shows the anchor members 726, 728, 730, 732 oriented toward the distal end 718 of the stent 710. However, it is also envisioned that the anchor members 726, 728, 730, 732 can be oriented toward the proximal end 716 of the stent 710.

[0076] It is envisioned that various combinations of anchor members 726, 728, 730, 732 are directed toward the proximal end 716 and distal end 718 of the stent 710. For example, one or more of the anchor members 726, 728, 730, 732 may be directed toward the proximal end 716 of the stent 710 and one or more of the anchor members 726, 728, 730, 732 may be directed toward the distal end 718 of the stent 710.

[0077] It is further understood that additional anchor members 726, 728, 730, 732 may be disposed on the stent 710, but are not visible in Figure 9. The additional anchor members 726, 728, 730, 732 are described herein with respect to Figures 10A-10B.

[0078] For example, Figure 10A is a cross-sectional view taken along line 10A-10A in Figure 9. Figure 10A shows four anchor members 726 evenly spaced around the circumference of a stent 710. The anchor members 726 can take a variety of shapes, including the exemplary shapes of other anchor members disclosed herein.

[0079] FIG. 10B is a cross-sectional view taken along line 10B-10B in FIG. 9. FIG. 10B shows two anchor members 728 spaced 180 degrees apart from one another in the circumferential direction. It can be seen that one of the anchor members 728 is visible in FIG. 9, while the other anchor member 728 is not visible in FIG. 9. It is further envisioned that the anchor members 730, 732 of the stent 710 are disposed about the periphery of the stent 710, similar to the anchor members 728 shown in FIG. 10B. In other words, the anchor members 730, 732 are hidden by the anchor members 728 in FIG. 10B. However, it is envisioned that the stent 710 includes two anchor members 730 spaced 180 degrees apart in the circumferential direction and two anchor members 732 spaced 180 degrees apart in the circumferential direction. Thus, stent 710 includes four anchor members 726 positioned along the proximal end 716 and two "vertical strips" of anchor members 728, 730, 732 spaced 180 degrees apart and aligned longitudinally along the outer surface of stent 710.

[0080] FIG. 11 illustrates another exemplary stent 810. The stent 810 may be similar in form and function to the stent 710 described herein. For example, the stent 810 may include a proximal end region 816, a distal end region 818, stent struts 812, an outer layer 814, four anchor members 826 disposed along the proximal end region 816, two anchor members 828 disposed along a mid-region of the stent, and two anchor members 830 disposed along a mid-region of the stent. However, FIG. 11 illustrates that the stent 810 may further include four anchor members 828 disposed along the distal end region 818 of the stent 810. Similar to the anchor members 726 of the stent 710 described above with respect to FIG. 10A, the four anchor members 828 may be uniformly spaced around the outer surface of the stent 810.

[0081] The anchor members 826, 828, 830, 832 can extend radially outward from the stent 810 at various angles, directions, etc. For example, Figure 11 shows the anchor members 826, 828, 830, 832 oriented toward the distal end 818 of the stent 810. However, it is also envisioned that the anchor members 826, 828, 830, 832 can be oriented toward the proximal end 816 of the stent 810.

[0082] It is also envisioned that various combinations of anchor members 826, 828, 830, 832 are directed toward the proximal end 816 and distal end 818 of the stent 810. For example, one or more of anchor members 826, 828, 830, 832 may be directed toward the proximal end 816 of the stent 810 and one or more of anchor members 826, 828, 830, 832 may be directed toward the distal end 818 of the stent 810.

[0083] FIG. 12 illustrates an exemplary anchor ring 942. The anchor ring 942 may include a plurality of anchor members 944, each with a proximal region attached to or disposed at a circumferential band 948. In some examples, the circumferential band 948 may be radially compressible and / or radially expandable and / or may be tightened to a smaller diameter. For example, in some examples, the circumferential band 948 may be constructed from an elastic material. Thus, the circumferential band 948 may be radially stretched to position the anchor ring 942 around a region of the tubular scaffold of the stent. The circumferential band 948 may be attached to the outer surface of the stent. For example, the circumferential band 948 may be bonded to the outer surface of the stent. However, in other examples, the circumferential band 948 may be sewn to the outer surface of the stent.

[0084] The anchor members 944 may be similar in shape and function to other anchor members described herein. For example, the anchor ring 942 may include four anchor members 944 spaced evenly around the outer surface of the circumferential band 948. In other examples, the four anchor members 944 may be unevenly spaced around the outer surface of the circumferential band 948. The anchor members 944 may take on a variety of shapes, including the exemplary shapes of other anchor members disclosed herein.

[0085] The anchor ring 942 may further include a circumferential band 946 coupled to a free end region (e.g., a tip) of each anchor member 944. In some examples, the circumferential band 946 may be formed integrally with the anchor members 944. In other examples, the base of each anchor member 944 may be secured to the circumferential band 946 such that the anchor members 944 are evenly or unevenly disposed around the circumference of the circumferential band 946. In some cases, the circumferential band 946 may pass through an opening disposed in the free end region of each anchor member 944.

[0086] 13 illustrates another exemplary stent 910. The stent 910 may be similar in shape and function to other stents described herein. For example, the stent 910 may include a proximal end region 916, a distal end region 918, stent struts 912, and an outer layer 914.

[0087] 13 further illustrates that the stent 910 can include a first anchor ring 942a (described above) attached distally to the proximal flare region 920 and a second anchor ring 942b attached proximally to the distal flare region 922. It can be seen that each of the anchor rings 942a, 942b can extend circumferentially around the outer surface of the stent 910. It can also be seen that a circumferential band 948 of each anchor ring 942a, 942b can be secured to the outer surface of the stent 910. In some examples, the circumferential band 948 of each of the anchor rings 942a, 942b can be glued, sewn, or attached using any suitable attachment method. In another example, the inner diameter of circumferential band 948 of each anchor ring 942a, 942b may be smaller than the outer diameter of stent 910, and thus, each circumferential band 948 of anchor ring 942a, 942b may be secured to stent 910 by radial compression or press-fit along the outer surface of stent 910. It can further be seen that flared region 920 of stent 910 may function to prevent anchor ring 942a from migrating proximally along stent 910, while flared region 922 of stent 910 may function to prevent anchor ring 942b from migrating distally along stent 910.

[0088] Figure 13 further shows that anchor members 944 of the first anchor member 942a extend radially outward from the stent 910 and point toward a distal end 918 of the stent 910. Similarly, Figure 13 further shows that anchor members 944 of the second anchor member 942b extend radially outward from the stent 910 and point toward a proximal end 916 of the stent 910.

[0089] 14 illustrates another exemplary stent 1010. The stent 1010 may be similar in form and function to other stents disclosed herein. The stent 1010 may include a proximal end region 1016, a distal end region 1018, stent struts 1012, and an outer layer 1014.

[0090] FIG. 14 further illustrates that the stent 1010 can include one or more “pairs” of anchor members 1026 , 1028 , 1030 , 1032 disposed along a midregion of the stent 1010 . For example, FIG. 14 shows that a stent 1010 may include a first pair of anchor members 1026 (one of which is not visible in FIG. 14 but is circumferentially 180 degrees away from the visible anchor members 1026) positioned adjacent the proximal end region 1016, a second pair of anchor members 1028 each circumferentially offset by 90 degrees from the pair of anchor members 1026, a third pair of anchor members 1030 (one of which is not visible in FIG. 14 but is circumferentially 180 degrees away from the visible anchor members 1030), and a fourth pair of anchor members 1032 each circumferentially offset by 90 degrees from the pair of anchor members 1030. It can be seen that each pair of anchor members 1026 , 1028 , 1030 , 1032 are longitudinally offset from one another along the outer surface of stent 1010 .

[0091] The anchor members 1026, 1028, 1030, 1032 can extend radially outward from the stent 101 at various angles, directions, etc. For example, Figure 14 shows the anchor members 1026, 1028, 1030, 1032 oriented toward the distal end 1018 of the stent 1010. However, it is also envisioned that the anchor members 1026, 1028, 1030, 1032 can be oriented toward the proximal end 1016 of the stent 1010.

[0092] It is also envisioned that various combinations of anchor members 1026, 1028, 1030, 1032 are directed toward the proximal end 1016 and distal end 1018 of the stent 1010. For example, one or more of the anchor members 1026, 1028, 1030, 1032 may be directed toward the proximal end 1016 of the stent 1010 and one or more of the anchor members 1026, 1028, 1030, 1032 may be directed toward the distal end 1018 of the stent 1010. In yet another example, the stent 1010 may include one or more of the anchor members 1026, 1028, 1030, 1032 directed toward the proximal end 1016 of the stent 1010, while one or more of the anchor members 1026, 1028, 1030, 1032 may be directed toward the distal end 1018 of the stent 1010.

[0093] 15 illustrates another exemplary stent 1110. The stent 1110 may be similar in form and function to other stents disclosed herein. The stent 1110 may include a proximal end region 1116, a distal end region 1118, stent struts 1112, and an outer layer 1114.

[0094] Figure 15 further illustrates that the stent 1110 can include a plurality of anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 attached to an outer surface of an intermediate region of the stent 1110. Additionally, Figure 15 illustrates that the anchor members 1126, 1128, 1130, 1132, 1134, 1136 are arranged in a helical fashion such that each of the anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 are circumferentially offset by 90 degrees from one another. For example, FIG. 15 shows that a proximal most anchor member 1126 may be positioned adjacent the proximal end region 1116 of the stent 1110, anchor member 1128 may be positioned distal to and offset 90 degrees from anchor member 1126, anchor member 1128 may be positioned distal to and offset 90 degrees from anchor member 1126, anchor member 1130 may be positioned distal to and offset 90 degrees from anchor member 1128, anchor member 1132 may be positioned distal to and offset 90 degrees from anchor member 1130, anchor member 1134 may be positioned distal to and offset 90 degrees from anchor member 1132, anchor member 1136 may be positioned distal to and offset 90 degrees from anchor member 1134, and anchor member 1138 may be positioned distal to and offset 90 degrees from anchor member 1136.

[0095] The anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 can extend radially outward from the stent 1110 at various angles, directions, etc. For example, Figure 15 shows the anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 directed toward the distal end 1118 of the stent 1110. However, it is also envisioned that the anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 may be directed toward the proximal end 1116 of the stent 1110.

[0096] In some examples, the stent 1110 includes one or more of the anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 directed toward the proximal end 1116 of the stent 1110, while one or more of the anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 are also envisioned to be directed toward the distal end 1118 of the stent 1110. In yet another example, it is envisioned that the stent 1110 includes one or more of the anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 directed toward the proximal end 1116 of the stent 1100, while one or more of the anchor members 1126, 1128, 1130, 1132, 1134, 1136, 1138 are directed toward the distal end 1118 of the stent 1110.

[0097] 16 illustrates another exemplary stent 1210. The stent 1210 may be similar in form and function to other stents disclosed herein. The stent 1210 may include a proximal end region 1216, a distal end region 1218, stent struts 1212, and an outer layer 1214.

[0098] 16 further illustrates that the stent 1210 may include one or more anchor members 1254. In some examples, the anchor members 1254 may be uniformly disposed about the circumference of the stent 1210. For example, while three anchor members 1254 are shown in FIG. 16, it is understood that the stent 1210 includes a fourth anchor member 1254 (not visible in the figure). The fourth anchor member 1254 may be spaced the same distance from the other anchor members 1254 shown in FIG. 16. Additionally, while FIG. 16 is described as including four anchor members 1254, it is envisioned that the stent 1210 may include 1, 2, 3, 4, 5, 6, 7, 8, or more anchor members 1254.

[0099] Each anchor member 1254 can include a first end 1256 and a second end 1258. As shown in FIG. 16, both the first end 1256 and the second end 1258 can be attached to the outer surface of the stent 1210. Additionally, FIG. 16 illustrates that an intermediate portion of each anchor member 1254 can extend radially outward from the outer surface of the stent 1210 to form an opening 2160 (e.g., a hole, a cavity, etc.) between the inner surface of the anchor member 1254 and the outer surface of the stent 1254. It can be seen that the opening 1254 provides a space for tissue growth, thereby allowing the stent 1210 to releasably engage the vessel wall. Additionally, while FIG. 16 illustrates the anchor members aligned (e.g., vertically) along the longitudinal axis of the stent 1210, it can be seen that in some examples, the anchor members 1254 can be positioned horizontally, diagonally, or any combination of vertical, horizontal, and diagonal along the stent 1210.

[0100] In some examples, the one or more anchor members 1254 may be comprised of the same material as the outer layer 1214. For example, the one or more anchor members 1254 and the outer layer 1214 may include a silicone material. Additionally, the one or more anchor members 1254 may be coupled (e.g., secured, attached, connected, etc.) to the outer layer 1214 and / or stent struts 1212 using a coupling material comprised of the same material used to construct both the one or more anchor members 1254 and / or the outer layer 1214. However, in other examples, the one or more anchor members 1254, the stent struts 1212, and / or the outer layer 1214 may be comprised of different materials. Additionally, in some examples, the material used to couple the one or more anchor members 1254 to the outer surface of the stent 1210 may be different than the material used to construct the one or more anchor members 1254, the stent struts 1212, and / or the outer layer 1214.

[0101] 17 illustrates another exemplary stent 1310. The stent 1310 may be similar in form and function to other stents disclosed herein. The stent 1310 may include a proximal end region 1316, a distal end region 1316, stent struts 1316, and an outer layer 1314.

[0102] FIG. 17 further illustrates that the stent 1310 may include one or more anchor members 1326 coupled to a base member 1364. The base member 1364 may generally be attached to the outer surface of the stent 1310. Additionally, as shown in FIG. 17, the base member 1364 may extend longitudinally along the outer surface of the stent 1310. In some examples, the anchor member 1326 may be monolithic with the base member 1364. In other words, the anchor member 1326 may be constructed of the same material as the base member 1364. Additionally, in some examples, the anchor member 1326 may be cut from the base member 1364 (e.g., a portion of the base member 1364 may be cut in the shape of the anchor member 1326 and extend radially outward from the base member 1364 to form a flap as shown in FIG. 17). However, in other examples, the anchor member 1326 may be formed independently of the base member 1364 and attached to the base member 1364 in a subsequent manufacturing step.

[0103] From Fig. 17, it can be seen that the anchor members 1326 can be positioned (e.g., attached) along any portion of the base member 1364. For example, Fig. 17 shows that the anchor members 1326 can be evenly positioned along the base member 1364. For example, in the configuration shown in Fig. 17, the anchor members 1326 can be evenly spaced and longitudinally offset from one another. However, in other examples, the anchor members 1326 can be non-uniformly positioned (e.g., attached) along the base member 1364.

[0104] It is further envisioned that the base member 1364 and / or the anchor members 1326 may be constructed from the same materials as the outer layer 1314. The base member 1364 may be bonded to the outer layer using a variety of materials, including the materials used to construct the outer layer 1314.

[0105] The materials that may be used in the various components of stent 10 (and / or other stents disclosed herein) and the various medical devices disclosed herein include materials generally associated with medical devices. For brevity, the following description will discuss stent 10 and other components of stent 10. However, the devices and methods described herein are not intended to be limiting, and the teachings described herein may be applied to other similar medical devices disclosed herein.

[0106] Stent 10 and other components of stent 10 may be made from metals, metal alloys, polymers (some examples are disclosed below), metal polymer composites, ceramics, combinations thereof, and the like, or other suitable materials. 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 esters, polyurethanes (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyetheresters (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (e.g., butylene / poly(alkylene ether) phthalates and / or other polyester elastomers, e.g., HYTREL® available from DuPont), polyamides (e.g., DURETHAN® or Elf® available from Bayer), and the like. Atochem's CRISTAMID™), elastomeric polyamides, block polyamide / ethers, polyether block amides (PEBA, available, for example, under the trade name PEBAX™), ethylene vinyl acetate copolymers (EVA), silicones, 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), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR™), polysulfone, nylon, nylon-12 (EMS AmericanSuch materials may include, but are not limited to, GRILAMID® available from Grillon, perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxies, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, and the like. In some embodiments, the sheath can be blended with a liquid crystal polymer (LCP). For example, the mixture can include up to about 6 percent LCP.

[0107] Some examples of suitable metals and metal alloys include stainless steels, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel titanium alloys, such as linear elastic and / or superelastic Nitinol; other nickel alloys, such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as INCONEL® 625; UNS: N06022, such as HASTELLOY® C-22™; HASTELLOY® C276™; Nickel-copper alloys (e.g., UNS:N04400, such as MONEL® 400, NICKELVAC™ 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, such as MP35-N™), nickel-molybdenum alloys (e.g., HASTELLOY® ALLOY®, etc.), 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, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY®, PHYNOX®); platinum strengthened stainless steels; titanium; combinations thereof, and the like; or other suitable materials.

[0108] In at least some embodiments, some or all of the stent 10 and other components of the stent 10 may be doped with, formed from, or otherwise include a radiopaque material. A radiopaque material is understood to be a material that can produce a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids a user of the stent 10 in determining its location. Some examples of radiopaque materials may 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 may also be incorporated into the design of the guidewire 10 to achieve the same results.

[0109] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is provided to the stent 10. For example, the stent 10 and other components of the stent 10 or portions thereof may be made of a material that does not substantially distort an image or create substantial artifacts (e.g., gaps in the image). The stent 10 and other components of the stent 10 or portions thereof may be made of a material that can be imaged by an MRI machine. Some materials that exhibit these characteristics include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY®, PHYNOX®, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, such as MP35-N™), nitinol, etc.

[0110] It will be understood that the present disclosure is in many respects merely illustrative. Changes may be made in details, particularly in matters of shape, size and order of steps, without exceeding the scope of the present disclosure. This may include, to the extent appropriate, using any of the features of one illustrative embodiment in other embodiments. The scope of the present disclosure is, of course, defined in the language of the appended claims.

Claims

1. 1. An expandable stent, comprising: a tubular scaffold including an inner surface, an outer surface, and a lumen extending therein; an outer layer disposed along the outer surface of the tubular scaffold; and a first preformed flap attached to the outer layer; wherein the preformed flaps are configured to releasably engage a vessel wall when the stent is implanted therein.

2. The stent of claim 1 , wherein the first preformed flap is configured to rotate between a radially extended position and a collapsed position.

3. 3. The stent of claim 1 or 2, wherein the first preformed flap is configured to redirect radially inward from a radially extended position.

4. 4. The stent of claim 1, wherein the first preformed flap includes a first attachment area disposed along a first edge of the flap, the first preformed flap being attached to the outer layer along the first attachment area.

5. The stent of any one of claims 1 to 4, wherein the first preformed flap is bonded to the outer layer using a bonding material.

6. The stent of claim 5 , wherein the outer layer, the first preformed flap, and the bonding material are formed from the same material.

7. 7. The stent of any one of claims 1-6, further comprising a second preformed flap, said first preformed flap and said second preformed flap being evenly spaced around a circumference of said tubular scaffold.

8. 8. The stent of claim 7, wherein the first preformed flap and the second preformed flap are longitudinally aligned with one another along the outer layer of the stent.

9. 8. The stent of claim 7, wherein the first preformed flap and the second preformed flap are longitudinally offset from one another along the exterior layer of the stent.

10. 10. The stent of any one of claims 1-9, wherein the first preformed flap is disposed along a proximal end region of the tubular scaffold and the second preformed flap is disposed along a distal end region of the tubular scaffold.

11. 11. The stent of claim 10, wherein the first preformed flap extends distally toward a distal end of the tubular scaffold and the second preformed flap extends proximally toward a proximal end of the tubular scaffold.

12. 12. The stent of any one of claims 1-11, further comprising a second preformed flap attached to the outer layer of the stent, a third preformed flap attached to the outer layer of the stent, and a fourth preformed flap attached to the outer layer of the stent, wherein the first preformed flap, the second preformed flap, the third preformed flap, and the fourth preformed flap are helically arranged around the tubular scaffold.

13. 1. A stent comprising: a tubular scaffold including an inner surface, an outer surface, and a lumen extending therein; an outer layer disposed along the outer surface of the tubular scaffold; and a plurality of preformed flaps formed separately from and attached to the outer layer, each of the preformed flaps configured to rotate between a radially extended position and a folded position; A stent, wherein each of the plurality of preformed flaps is configured to releasably engage a vessel wall when the stent is implanted in the vessel wall.

14. The stent of claim 13 , wherein each of the plurality of preformed flaps is configured to deflect radially inward from a radially extended position.

15. The stent of claim 14 , wherein each of the plurality of preformed flaps is bonded to the outer layer using a bonding material.

Images