Stent with anti-slip function

Abstract

To provide an expandable stent having improved anti-migration capability.SOLUTION: A medical device for treating a body lumen, such as a medical stent, includes an expandable scaffold configured to shift from a radially collapsed state to a radially expanded state. The stent includes a coating disposed along the outer surface of the expandable scaffold, where at least a portion of the coating includes a plurality of anti-migration members and one or more preferential separation regions. Each preferential separation region is configured to permit first and second regions of the coating to separate from one another along the preferential separation region therebetween as the expandable scaffold shifts from the radially collapsed state to the radially expanded state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to medical devices, methods of manufacturing medical devices, and uses thereof. More particularly, the present disclosure relates to expandable stents with anti-shear features, and example methods of manufacturing and using the same. [Background technology]

[0002] Implantable medical devices (e.g., expandable stents) may be designed to treat strictures in body lumens and / or provide a flow path for the flow of digested material, blood, or other fluids following a medical procedure. Some medical devices may include radially expandable or self-expandable stents, which may be implanted transluminally, for example, via an endoscope or stent delivery vehicle. Furthermore, some stents may be implanted in various body lumens, such as the esophageal alimentary tract, the gastrointestinal tract (including the intestines, stomach, and colon), the airway, the urinary tract, the biliary tract, and the vascular system.

[0003] In some cases, it may be desirable to design a stent to be sufficiently flexible while maintaining sufficient radial force to open a body lumen at the treatment site. However, the compressibility and flexibility that aid in stent delivery for some stents can also make them prone to migration from their initial deployed position after deployment. For example, stents designed to be positioned within the esophageal or gastrointestinal tract may be prone to migration due to peristalsis (i.e., the involuntary contraction and relaxation of the muscles of the esophagus, intestine, and colon, which pushes contents through the tract). Furthermore, the generally moist and inherently smooth environments of the esophagus, intestine, and colon contribute to the tendency of stents to migrate when deployed therein. One method of reducing stent migration may include exposing the bare metal portion of the stent to the tissue of the body lumen. The stent scaffold may provide a structure that promotes tissue ingrowth into its mesh or opening. Tissue ingrowth may anchor the stent in place and reduce the risk of stent migration.

[0004] Furthermore, while it is important to design a stent that reduces the degree to which the stent slips within a body lumen, it is also important to design a stent that can be easily removed from and / or repositioned within a body lumen after deployment. Stents that include bare (i.e., uncoated) portions designed to promote tissue ingrowth (e.g., to reduce stent slippage, as described above) may be more difficult to remove once tissue has established the stent within the body lumen. Furthermore, it is also important to design a stent that facilitates loading and deployment from a stent delivery device. One method for reducing stent stiffness and increasing radial deployment force may include reducing the thickness, and therefore the total volume, of a coating (e.g., an anti-shear coating) applied to the stent. Therefore, in some cases, it may be desirable to design a stent with a coating that has both anti-shear functionality and a reduced total volume. Examples of medical devices with coatings that have anti-shear functionality and a reduced volume are disclosed herein. Summary of the Invention [Means for solving the problem]

[0005] The present disclosure provides alternatives for medical device design, materials, manufacturing methods, and uses. An exemplary medical stent for treating a body lumen includes an expandable scaffold including a first end region, a second end region opposite the first end region, and an outer surface, where the expandable scaffold is configured to shift from a radially collapsed state to a radially expanded state. The stent further includes a coating disposed along the outer surface of the expandable scaffold. At least a portion of the coating includes a plurality of anti-shear members. The coating further includes a preferential separation region, the preferential separation region being positioned between the first region of the coating and the second region of the coating. The preferential separation region is further configured to allow the first region of the coating to separate from the second region of the coating along the preferential separation region therebetween as the expandable scaffold shifts from the radially collapsed state to the radially expanded state.

[0006] Alternatively or additionally to any of the above embodiments, the preferential separation regions are configured to prevent the coating from separating from the outer surface of the expandable scaffold when the expandable scaffold shifts from a radially collapsed state to a radially expanded state.

[0007] Alternatively or additionally to any of the above embodiments, separation of the first region of the coating from the second region of the coating produces holes in the coating along the preferential separation regions.

[0008] Alternatively or additionally to any of the above embodiments, the holes extend through the wall of the coating. Alternatively or additionally to any of the above embodiments, the holes extend through only a portion of the wall of the coating.

[0009] Alternatively or additionally to any of the above embodiments, the medical stent further comprises a plurality of holes disposed in the coating, the plurality of holes being aligned along the longitudinal axis of the stent.

[0010] Alternatively or additionally to any of the above embodiments, alignment of the plurality of holes in the preferential separation region results in a perforated preferential separation region. Alternatively or additionally to any of the above embodiments, the preferential separation region extends continuously along the longitudinal axis of the stent from the first end region to the second end region.

[0011] Alternatively or additionally to any of the above embodiments, the preferential separation regions extend linearly along the longitudinal axis of the stent. Alternatively or additionally to any of the above embodiments, the preferential separation regions extend non-linearly along the longitudinal axis of the stent.

[0012] Alternatively or additionally to any of the above embodiments, the expandable scaffold includes a plurality of braided filaments, the plurality of filaments arranged to define a plurality of cells therebetween, and the region of preferential separation positioned within one of the plurality of cells.

[0013] Another medical stent for treating a body lumen includes an expandable scaffold including a first end region, a second end region opposite the first end region, and an outer surface, where the expandable scaffold is configured to shift from a radially collapsed state to a radially expanded state. The stent further includes a coating disposed along the outer surface of the expandable scaffold, at least a portion of the coating including a plurality of anti-shear members disposed thereon. Moreover, the coating further includes a plurality of preferential separation regions, each of the preferential separation regions spaced apart from one another, and each of the preferential separation regions configured to define a hole in the coating when the expandable scaffold shifts from the radially collapsed state to the radially expanded state.

[0014] Alternatively or additionally to any of the above embodiments, each of the preferential separation regions is positioned between the first region of the coating and the second region of the coating, and each of the preferential separation regions is configured to allow the first region of the coating to separate from the second region of the coating along a respective preferential separation region therebetween as the expandable scaffold shifts from the radially collapsed state to the radially expanded state.

[0015] Alternatively or additionally to any of the above embodiments, each of the plurality of preferential separation regions is configured to prevent separation of the coating from an outer surface of the expandable scaffold when the expandable scaffold shifts from a radially collapsed state to a radially expanded state.

[0016] Alternatively or additionally to any of the above embodiments, each hole in the preferential separation region extends entirely through the wall of the coating. Alternatively or additionally to any of the above embodiments, each hole in the preferential separation region extends through only a portion of the wall of the coating.

[0017] Alternatively or additionally to any of the above embodiments, each of the preferential separation regions extends continuously along the longitudinal axis of the stent from the first end region to the second end region.

[0018] Alternatively or additionally to any of the above embodiments, each of the preferential separation regions are spaced apart from one another along the longitudinal axis of the stent. Alternatively or additionally to any of the above embodiments, the expandable scaffold includes a plurality of braided filaments arranged to define a plurality of cells therebetween, and each of the preferential separation regions is positioned within a corresponding one of the plurality of cells.

[0019] Another medical stent includes an expandable scaffold including a first end region, a second end region opposite the first end region, and an outer surface, the expandable scaffold configured to shift from a radially collapsed state to a radially expanded state. The expandable scaffold further includes a plurality of braided filaments defining a plurality of cell openings located therebetween. The stent further includes a coating disposed along the outer surface of the expandable scaffold, at least a portion of the coating including a micropattern, the micropattern including a plurality of anti-shear members. The micropattern is further disposed with the cell openings between the braided stent filaments.

[0020] 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.

[0021] The present disclosure may be more fully understood from the following detailed description considered in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0022] [Figure 1] 1A and 1B illustrate an exemplary stent including a coated region. [Figure 2] FIG. 10 illustrates another exemplary stent including coated regions and micropatterns. [Figure 3] FIG. 3 is a detailed view of a portion of the stent shown in FIG. 2. [Figure 4] FIG. 4 shows a cross-sectional view of the stent shown in FIG. 2 taken along line 4-4. [Figure 5] FIG. 10 illustrates another exemplary stent including coated regions and micropatterns. [Figure 6] FIG. 6 is a detailed view of a portion of the stent shown in FIG. 5. [Figure 7] FIG. 10 illustrates another exemplary stent including coated regions and micropatterns. [Figure 8] FIG. 8 is a detailed view of a portion of the stent shown in FIG. 7. [Figure 9] FIG. 10 illustrates another exemplary stent in a pre-deployed configuration having coated regions and micropatterns. [Figure 9A] 9A shows a cross-sectional view of the stent shown in FIG. 9 along line 9A-9A. [Figure 10] FIG. 10 illustrates the exemplary stent shown in FIG. 9 in a deployed configuration. [Figure 11] FIG. 11 illustrates a portion of the exemplary stent shown in FIG. [Figure 11A] FIG. 10 illustrates another exemplary stent in a pre-deployed configuration having coated regions and micropatterns. [Figure 11B] FIG. 11B illustrates a portion of the exemplary stent shown in FIG. 11A. [Figure 11C] FIG. 11B illustrates the exemplary stent shown in FIG. 11A in a deployed configuration. [Figure 12] FIG. 10 illustrates another exemplary stent in a pre-deployed configuration having coated regions and micropatterns. [Figure 12A]FIG. 12A shows a cross-sectional view of the stent shown in FIG. 12 along line 12A-12A. [Figure 13] FIG. 13 illustrates the exemplary stent shown in FIG. 12 in a deployed configuration. [Figure 13A] FIG. 13A shows a cross-sectional view of the stent shown in FIG. 13 along line 13A-13A. DETAILED DESCRIPTION OF THE INVENTION

[0023] While the present disclosure is susceptible to various modifications and alternative forms, specifics thereof have been shown in the drawings and will be described in detail for purposes of illustration. It is to be understood, however, that the intention is not to limit the disclosure 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 disclosure.

[0024] For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. All numerical values, whether expressly stated or not, are assumed to be modified herein by the term "about." The term "about" generally refers to a range of numbers 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" can include numbers that are rounded to the nearest significant figure.

[0025] The recitation of numerical ranges by endpoints 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," and "the" include the plural references unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally utilized in its sense including "and / or" unless the context clearly dictates otherwise.

[0026] It should be noted that references herein to "embodiments," "some embodiments," "other embodiments," etc., indicate that the described embodiments may include one or more particular features, structures, and / or characteristics. However, such references do not necessarily imply that all embodiments include the 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 the particular feature, structure, and / or characteristic may also be used in connection with other embodiments, whether or not explicitly stated, unless expressly stated otherwise.

[0027] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are similarly numbered, and which, while not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the present disclosure.

[0028] As mentioned above, implantable medical devices may be designed to treat strictures in a body lumen and / or provide a flow path for the flow of ingested or other substances or fluids following an invasive medical procedure. Examples disclosed herein may include radially expandable or self-expandable stents. Expandable stents may be implanted transluminally via an endoscope or another desired delivery means. Furthermore, some stents may be implanted in various body lumens, such as the esophagus, the gastrointestinal tract, including the intestine and colon, the airway, the urinary tract, the biliary tract, including the bile and / or pancreatic duct, and the vascular system.

[0029] In some cases, it may be desirable to design a stent to have sufficient radial force to open the body lumen at the treatment site, while also being flexible enough to allow it to follow tortuous body lumens during delivery. However, the compressibility and flexibility that aid in the delivery of some stents can also result in the stent being prone to migration from its original deployment position. For example, a stent designed to be positioned in the esophagus or intestine may have a tendency to migrate due to peristalsis (i.e., the involuntary contraction and relaxation of the muscles of the esophagus, intestine, and colon that pushes the contents of the tract). Furthermore, the generally moist and naturally smooth environments of the esophagus, intestine, and colon contribute to the tendency of a stent to migrate when deployed therein.

[0030] Furthermore, while it is important to design a stent that reduces the degree to which the stent slips within a body lumen, it is also important to design a stent that can be easily removed from and / or repositioned within a body lumen after deployment. Stents that include bare (i.e., uncovered) portions designed to promote tissue ingrowth (e.g., to reduce stent slippage as described above) may be more difficult to remove once tissue has established the stent within the body lumen. One method for reducing the force required to remove a stent from a body lumen may include covering a portion of the stent to create a physical barrier between the body lumen and the outer surface of the stent (e.g., reducing the surface area of ​​the stent that can be established by tissue ingrowth). One method for reducing stent slippage while maintaining the ability to remove and / or reposition the stent may include designing the outer surface of the stent to have an anti-slip surface texture. For example, a stent scaffold may include a gripping structure (e.g., a micropatterned gripping structure) that improves the surface friction of the stent. The increased surface friction may anchor the stent in place and reduce the risk of stent migration. Exemplary medical devices including micropatterned surface textures are disclosed below.

[0031] FIG. 1 illustrates an exemplary implantable medical device, designated as a stent 110. Although depicted as a stent, implantable medical device 110 may be any of several devices that can be introduced endoscopically, subcutaneously, percutaneously, or surgically and positioned within an organ, tissue, or lumen, such as the esophagus, intestine, colon, urethra, trachea, bronchi, bile duct, or blood vessel. Stent 110 may be configured to be positioned within a body lumen for a variety of medical applications. For example, stent 110 may be used to treat a stricture within a body lumen. Furthermore, stent 110 may be used to provide a passageway for food or other ingested material to pass therethrough without directly contacting adjacent tissue. It is contemplated that the examples described herein may be utilized, for example, in the esophageal alimentary tract, as well as the gastrointestinal, vascular, urinary, biliary, respiratory, and renal tracts. In some cases, the stent 110 (eg, an intestinal stent, an esophageal stent, a vascular stent, an airway stent, a bronchial stent, etc.) may include an expandable scaffold.

[0032] The expandable scaffold of the stent 110 may have a first end region 112 and a second end region 114 positioned at an end of the stent 110 opposite the first end region 112. In some cases, the first end region 112 may extend to a first end of the stent 110 and the second end region 114 may extend to a second end of the stent 110 opposite the first end. The expandable scaffold of the stent may include a central region 116 extending between the first end region 112 and the second end region 114, or otherwise positioned between the first end region 112 and the second end region 114 of the implantable medical device 110, to form an expandable tubular framework or scaffold having open ends and defining a lumen extending therethrough. 1, the first end region 112 and / or the second end region 114 may, if desired, include a flared portion having an enlarged outer diameter in a radially expanded configuration that is greater than the outer diameter of the central region 116. For example, FIG. 1 shows the first end region 112 and the second end region 114 both having an outer diameter that is greater than the outer diameter of the central region 116 in the radially expanded configuration. In other embodiments, only one of the first end region 112 and the second end region 114 may include a flared portion, or, if desired, the expandable scaffolding of the stent 110 may have a constant outer diameter along its entire length.

[0033] The multiple strut members 118 may be arranged in a variety of different designs and / or geometric patterns to form the expandable tubular framework or scaffold of the stent 110. Numerous designs, patterns, and / or configurations of stent cell openings (e.g., openings between adjacent strut members), strut thickness, strut design, and stent cell shapes are contemplated and may be utilized with the embodiments disclosed herein. Additionally, examples of self-expandable stents disclosed herein may include stents having one or more strut members 118 joined together to form a rigid and / or semi-rigid stent structure. In some examples disclosed herein, the collection of strut members 118 forming the rigid and / or semi-rigid framework structure may be referred to as a scaffold. For example, the strut members 118 may be wires or filaments that are braided, twisted, knitted, woven, interwoven, crocheted, or the like to form the expandable scaffold or framework of the stent 110. The strut members (e.g., wires or filaments) 118 of the stent 110 may be configured to self-expand to an expanded diameter when released. Alternatively, the strut members 118 may be comprised of a monolithic structure (e.g., a cylindrical tubular member), such as a single cylindrical tubular laser-cut nitinol tubular member, with the remaining portions forming the strut members 118. The monolithic structure of the stent 110 may be configured to self-expand to an expanded diameter when released.

[0034] The expandable scaffold of stent 110 in at least some examples disclosed herein can be composed of a variety of materials. For example, the expandable scaffold of stent 110 can be composed of a metal (e.g., nitinol). In other cases, the expandable scaffold of stent 110 can be composed of a polymeric material (e.g., PET). In still other cases, the expandable scaffold of stent 110 can be composed of a combination of a metallic material and a polymeric material. Furthermore, the expandable scaffold of stent 110, or portions thereof, can include a bioabsorbable and / or biodegradable material.

[0035] As mentioned above, in some cases, the stent 110 may include a coating 120 (shown in FIG. 1 as a dot pattern) disposed along the expandable scaffolding 118 of the stent 110. In some instances, the coating 120 may be referred to as a first coating layer or a base coating layer. The base coating layer 120 may be applied to the expandable scaffold prior to the application of additional coating layers (described below). While FIG. 1 depicts the coating 120 extending along the entire length and circumference of the stent 110, in some instances, the coating 120 may be disposed along only a portion of the stent 110. Furthermore, the coating 120 may completely cover the stent 110, thus spanning or intersecting the meshes (e.g., cell openings) between the struts 118 of the expandable framework or scaffold of the stent 110. In other words, coating 120 may completely surround the expandable framework or scaffold of stent 110, completely occluding the meshwork of the expandable framework and thereby preventing tissue ingrowth into the lumen of stent 110. While FIG. 1 shows coating 120 extending along the outer surfaces of strut members 118, it is contemplated that coating 120 may also extend along the inner surfaces of strut members 118 and / or completely surround or encapsulate strut members 118. Additionally, as described in more detail below, coating 120 may be applied by spraying, dipping, spinning, or attaching a polymeric sheet or tube to the inner and / or outer surfaces of stent filaments 18.

[0036] In some cases, coating 120 may include an elastomeric or non-elastomeric material. Furthermore, a portion of coating 120 may be composed of a suitable material, such as a biostable material. For example, coating 120 may include a polymeric material, such as silicone, polytetrafluoroethylene, or polyurethane, or other materials, including those disclosed herein. Furthermore, a portion of coating 120 may be a biostable material. For purposes of this description, a biostable material may be defined as a material that does not biodegrade. For example, coating 120 may include a polymeric material, such as silicone, polytetrafluoroethylene, or polyurethane, or other materials, including those disclosed herein. In other examples, coating 120 may be composed of a fabric, PEEK, ABS, PLS, or other suitable material. Furthermore, coating 120 may include a 3D printed material.

[0037] As mentioned above, in some instances, it may be desirable to design the stent 110 to include one or more features that increase the surface friction of the stent 110. For example, FIG. 2 illustrates that in some instances, the coating of the stent 110 may include a micropatterned coating layer 122 comprised of multiple anti-slip elements in addition to or as an alternative to the base coating layer 120. Details of the individual anti-slip elements that collectively form the micropatterned coating layer 122 are described in further detail below with reference to FIG. 3. The micropatterned coating layer 122 may be designed to reduce stent slippage while maintaining the ability to remove and / or reposition the stent 110. As mentioned above and described in further detail below, the anti-slip elements that form the micropatterned coating layer 122 may include multiple gripping structures (e.g., micropatterned gripping structures) that improve the surface friction of the stent 110.

[0038] 2 further illustrates that micropattern coating layer 122 may not be formed along the entire length and / or circumference of the expandable scaffolding of stent 110, but may be disposed along only selected portions of the expandable scaffolding of stent 110 in various configurations. For example, FIG. 2 illustrates micropattern coating layer 122 disposed about stent 110 in a helical configuration. In other words, micropattern coating layer 122 is comprised of one or more, or multiple, helical strips that extend helically around the outer surface of stent 110.

[0039] 2 shows that the helical micropattern 122 extending along the stent 110 includes a pitch angle. However, it can be understood that in other examples, the pitch angle of the micropattern coating layer 122 (forming one or more helical strips) can vary. In other words, other exemplary stent designs may include a helically configured micropattern coating layer 122 having a pitch angle that is greater or less than the pitch angle shown in FIG. 2.

[0040] 2 illustrates the micropattern coating layer 122 extending from the first end region 112 (including along the flared portion of the stent 110) to the second end region 114 (including along the flared portion of the stent 110) of the stent 110. However, it is contemplated that the micropattern coating layer 122 may extend along any portion of the stent 110. For example, the micropattern coating layer 122 may be disposed only along the central region 116. In other examples, the micropattern coating layer 122 may be disposed along the central region 116 and one or more of the first end region 112 and / or second end region 114 of the stent 110.

[0041] Figure 3 is a detailed view of Figure 2. Figure 3 illustrates that the micropattern coating layer 122 shown in Figure 2 may be comprised of a collection of individual anti-shear elements 124 (e.g., a plurality of anti-shear elements 124) extending from a base of the micropattern coating layer 122. The anti-shear elements 124 may be spaced relatively closely together and collectively form a surface texture or gripping surface that reduces the likelihood of slippage when the stent 110 is deployed within a body lumen.

[0042] 3 further illustrates that each of the individual anti-shear elements 124 may be cylindrically (e.g., pillar-shaped). However, it is contemplated that the individual anti-shear elements 124 may have a variety of shapes. For example, each anti-shear element 124 may be round, square, triangular, oval, polygonal, diamond-shaped, pillar-shaped, rectangular, peg-shaped, hook-shaped, any suitable geometric shape, or combinations thereof. Other exemplary shapes of the anti-shear elements 124 are disclosed in U.S. Patent Application Publication No. 2013 / 0268063, which is incorporated herein by reference in its entirety.

[0043] In some examples, the micropattern coating layer 122 (including the anti-slip elements 124) may be formed by first depositing the material utilized for the micropattern coating layer 122 onto the base coating layer 120, and then stamping the micropattern coating layer 122 to form the individual anti-slip elements 124 (e.g., stamping a portion of the micropattern coating layer 122 to form each of the anti-slip elements 124 that collectively form the micropattern coating layer 122). In some examples, the micropattern coating layer 122 may include liquid silicone applied to the base coating 120. For example, the liquid silicone may be layered on a mold with the micropattern inlaid. After this silicone layer is cured, it may be attached to the base coating 120 via an additional liquid silicone layer (e.g., a layer of liquid silicone may be used to attach the molded micropattern silicone to the base coating 120). However, in other embodiments, the micropattern coating layer may be cast directly onto the base coating layer 120 or may be cast and then applied to the base coating layer 120 .

[0044] 3 may be formed by stamping the base coating layer 120. For example, in some cases, the anti-slip elements 124 may be formed by stamping a portion of the base coating layer 120 to form each anti-slip element 124.

[0045] In yet another example, the micropattern coating layer 122 (including the anti-shear elements 124) may be formed along the stent 110 by positioning a sleeve (e.g., a sheath, a tube, etc.) along the filaments 118 of the stent 110. It will be appreciated that the sleeve may be formed to include the micropattern coating layer 122 before being positioned and secured to the stent 110. For example, the sleeve including the micropattern coating layer 122 shown in FIG. 3 may be formed in a first manufacturing step, such as by molding, whereby the sleeve is subsequently bonded to the outer surface of the stent 110 in a second manufacturing step.

[0046] Figure 4 is a cross-sectional view taken along line 4-4 of Figure 2. Figure 4 shows stent filaments 118 arranged about a central longitudinal axis 130 of stent 110. Figure 4 further shows base coating layer 120 surrounding each individual filament 118. Figure 4 also shows that base coating layer 120 may extend across cell openings in stent 110.

[0047] Further, the detailed view of FIG. 4 shows a cross-sectional view of the base coating layer 120, the micropattern coating layer 122, and the plurality of anti-shear members 124 described above. As shown in the detailed view of FIG. 4, the base coating layer 120 can have a thickness "X." In some examples, the thickness of the base coating layer 120 can be about 20-80 microns, about 30-70 microns, about 40-60 microns, about 40-70 microns, about 30-80 microns, or about 50 microns. Further, the detailed view of FIG. 4 shows that the total thickness of the coating on the stent scaffolding, including the base coating layer 120 and the micropattern coating layer 122, can have a thickness "Y." In some examples, the total thickness of the coating on the stent scaffold (the combined thickness of the base coating 120 and the micropattern coating layer 122 up to the tip of the anti-shear member 124) can be about 40-220 microns, about 80-180 microns, about 60-200 microns, about 80-170 microns, about 100-170 microns, about 90-150 microns, about 100-140 microns, about 110-130 microns, or about 120 microns.

[0048] It can be appreciated that the thicker portions of micropattern coating 122 (compared to other thinner portions of base coating layer 120) may form an outwardly extending surface texture or gripping surface that reduces the likelihood of slippage when stent 110 is deployed within a body lumen, while the reduced thickness of base coating layer 120 of the coating may allow stent 110 to radially collapse and / or expand with less resistance. From the above discussion, it can be appreciated that the addition of a micropattern coating layer (e.g., micropattern coating layer 122) to the outer surface of an exemplary stent will increase the total coating volume of the stent. It can also be appreciated that, in some instances, this additional coating volume may increase the axial stiffness and / or radial deployment force of the stent (e.g., stent 110). Thus, it can further be appreciated that application of a micropattern coating layer (e.g., layer 122) along only a portion of the outer surface of a stent may reduce (e.g., mitigate) undesirable effects associated with having a micropattern coating layer disposed along the entire outer surface of the stent. In other words, it may be desirable to reduce the overall volume of the stent (thereby improving the stent's stiffness and radial deployment force) by applying a micropatterned coating layer (e.g., layer 122) along only selected portions of the stent. Furthermore, reducing the overall thickness of the stent's coating may also provide additional benefits when attempting to load the stent into a delivery device. For example, confining the coating to various locations may not only reduce the overall coating volume, but may also help maintain the mechanical properties of the stent so that foreshortening and radial forces are not significantly compromised, thereby allowing the stent to be compressed to a more significantly reduced diameter, facilitating loading of the stent into a stent delivery device.

[0049] 4 further illustrates that the anti-shear elements 124 can be disposed along the stent 110 such that they extend radially away from the expandable scaffold strut members 118. As discussed above, the base coating layer 120 and / or the micropattern coating layer 122 can extend across the mesh or openings between adjacent struts 118. Furthermore, FIG. 4 further illustrates that the micropattern coating layer 122 can be positioned on the outermost surface of the stent 110 such that it contacts the inner surface of a body lumen within which the stent 110 may be disposed.

[0050] It can be appreciated that the micropattern coating layer 122 may form a textured and / or roughened surface designed to contact and engage with the inner surface of an exemplary body lumen, as shown in Figure 4. For example, in some cases, the textured surface of the micropattern coating layer 122 may temporarily anchor the coated portion of the stent 110 along the inner surface of the exemplary body lumen.

[0051] FIG. 5 illustrates another exemplary stent 210. The stent 210 may be similar in form and function to the stent 110 described above. For example, the stent 210 may include an expandable scaffold (including one or more braided filaments 218 arranged to form the expandable scaffold) extending from a first end region 212 to a second end region 214. A central region 216 may extend between the first end region 212 and the second end region 214. The first end region 212 and / or the second end region 214 may include a flared portion having an enlarged outer diameter greater than the outer diameter of the central region 216 in a radially expanded configuration, if desired. Additionally, the stent 210 may include a base coating layer 220 disposed along the expandable scaffold of the stent 210.

[0052] FIG. 5 further illustrates that a portion of the stent 210 may include a separate micropattern coating layer 222 comprised of multiple anti-shear elements similar to those described above. However, the micropattern coating layer 222 depicted in FIG. 5 may be configured in a "dot" pattern. In other words, the micropattern coating layer 222 may include multiple individual, discrete areas (e.g., discontinuous patches) of coating spaced apart from other individual, discrete areas (e.g., other discontinuous patches) of the coating of the micropattern coating layer 222, with each individual discrete area of ​​the micropattern coating layer 222 including multiple anti-shear elements formed therein. The discontinuous patches of the micropattern coating layer 222 may be disposed along the length and / or circumference (or any portion) of the stent 210. Each area / patch (e.g., region, portion, etc.) of the anti-shear elements may be separate and spaced apart from one another. Furthermore, each area / patch of the anti-shear elements may be configured in any desired shape, such as a circle (e.g., a dot), if desired. The sum of all the discontinuous areas of the anti-slip element may be referred to as a micropattern coating layer 222 as shown in FIG.

[0053] In some examples, one or more of the "dots" of micropattern coating layer 222 may be aligned with one another along the entire length (or a portion thereof) of stent 210. However, in other examples, the dots of micropattern coating layer 222 may not be aligned with one another. Rather, the dots of micropattern coating layer 222 may be arranged in various patterns along stent 210. In some examples, the dots of micropattern coating layer 222 may be arranged in a random distribution.

[0054] 5 illustrates micropattern coating layer 222 extending from first end region 212 (including along the flared portions of stent 210) to second end region 214 (including along the flared portions of stent 210). However, it is contemplated that micropattern coating layer 222 may extend along any portion of stent 210. For example, micropattern coating layer 222 may be positioned along only central region 216, or along central region 216 and one or more of first end region 212 and / or second end region 214 of stent 210.

[0055] Figure 6 is a detailed view of Figure 5. Similar to Figure 3, Figure 6 illustrates that the micropattern coating layer 222 shown in Figure 3 can include an array of individual anti-shear elements 224 (e.g., a plurality of anti-shear elements 224) extending radially outward from a base of the micropattern coating layer 222. The anti-shear elements 224 can be spaced relatively closely together and collectively form a surface texture or gripping surface that reduces the likelihood of slippage when the stent 210 is deployed within a body lumen.

[0056] Additionally, FIG. 6 illustrates that multiple anti-shear elements 224 may be arranged to collectively form a circle (e.g., one "dot" in the dot micropattern coating layer 222 described above). It is contemplated that the anti-shear elements 224 may be formed similarly to the other micropattern structures described herein. For example, the micropattern coating layer 222 shown in FIG. 6 may be formed by applying the material utilized to form the micropattern coating layer 222 onto the base coating layer 220 and then stamping the micropattern coating layer 222 into individually shaped anti-shear elements 224. Alternatively, the micropattern coating layer 222 may be formed separately and then applied to the base coating layer 220. Additionally, the micropattern coating layer 222 shown in FIG. 6 may be disposed along any portion of the stent 210.

[0057] FIG. 7 illustrates another exemplary stent 310. The stent 310 may be similar in form and function to the other exemplary stents described above. For example, the stent 310 may include an expandable scaffold (including one or more braided filaments 318 arranged to form the expandable scaffold) extending from a first end region 312 to a second end region 314. A central region 316 may extend between the first end region 312 and the second end region 314. The first end region 312 and / or the second end region 314 may include a flared portion having an enlarged outer diameter greater than the outer diameter of the central region 316 in a radially expanded configuration, if desired. Additionally, the stent 310 may include a base coating layer 320 disposed along the expandable scaffold of the stent 310.

[0058] FIG. 7 further illustrates that a portion of the stent 310 may include a separate micropattern coating layer 322 comprised of multiple anti-shear elements similar to those described above. However, the micropattern coating layer 322 depicted in FIG. 7 may include multiple individual "diamond" patterns. In other words, the micropattern coating layer 322 may include multiple individual, discontinuous areas (e.g., discontinuous patches) of coating spaced apart from other individual, discontinuous areas (e.g., other discontinuous patches) of the coating of the micropattern coating layer 322, with each individual discontinuous area of ​​the micropattern coating layer 322 including multiple anti-shear elements formed therein. The discontinuous patches of the micropattern coating layer 322 may be disposed along the length and / or circumference (or any portion) of the stent 310. Each area / patch (e.g., region, section, etc.) of the anti-shear elements may be separate and spaced apart from one another. Furthermore, each area / patch of the anti-shear elements may be configured in any desired shape, such as a diamond, if desired. The sum of all the discontinuous areas of the anti-slip element may be referred to as a micropattern coating layer 322 as shown in FIG.

[0059] In some examples, one or more of the "diamonds" of micropattern coating layer 322 may be aligned with one another along the entire length (or a portion thereof) of stent 310. However, in other examples, the diamonds of micropattern coating layer 322 may not be aligned with one another. Rather, the diamonds of micropattern coating layer 322 may be arranged in various patterns along stent 310. In some examples, the diamonds of micropattern coating layer 322 may be arranged in a random distribution.

[0060] 7 illustrates the micropattern coating layer 322 extending from the first end region 312 (including along the flared portion of the stent 310) to the second end region 314 (including along the flared portion of the stent 310). However, it is contemplated that the micropattern coating layer 322 may extend along any portion of the stent 310. For example, the micropattern coating layer 322 may be positioned along only the central region 316, or along the central region 316 and one or more of the first end region 312 and / or second end region 314 of the stent 310.

[0061] Figure 8 is a detailed view of Figure 7. Figure 8 illustrates that the micropattern coating layer 322 shown in Figure 7 may be comprised of an array of individual anti-shear elements 324 (e.g., a plurality of anti-shear elements 324). Each anti-shear element 324 may be spaced relatively closely together, collectively forming a surface texture or gripping surface that reduces the likelihood of slippage when the stent 310 is deployed within a body lumen.

[0062] Additionally, FIG. 8 illustrates that multiple anti-shear elements 324 may be arranged to collectively form a diamond shape (e.g., the "diamond" of one of the micropatterns 322 described above). It is contemplated that the anti-shear elements 324 may be formed similarly to the other micropatterns described herein. For example, the micropattern coating layer 322 shown in FIG. 8 may be formed by applying the material utilized to form the micropattern coating layer 322 onto the base coating layer 320 and then stamping the micropattern coating layer 322 into individually shaped anti-shear elements 324. Alternatively, the micropattern coating layer 322 may be formed separately and then applied to the base coating layer 320. Additionally, the micropattern coating layer 322 shown in FIG. 8 may be disposed along any portion of the stent 310.

[0063] In some instances (such as the exemplary micropatterns described in connection with FIGS. 7 and 8 ), one or more of the individual diamond-shaped patches that collectively form the micropattern coating layer 322 may be positioned between adjacent filaments 318 of the stent 310. In other words, the micropattern coating layer 322 may be formed so as to reduce the overall radial thickness of the stent 310 in areas having the micropattern coating layer 322 by being located in areas where the individual anti-shear elements 324 fit entirely between the struts 318 of the stent.

[0064] While the examples described above with reference to Figures 2-8 illustrate several different micropattern coating layer configurations, it is understood that a variety of different micropattern coating layer configurations are contemplated. For example, the micropattern coating layer may include stripes extending along the longitudinal axis of the stent and / or bands extending circumferentially around the outer surface of the stent. In other examples, the micropattern coating layer may include a chevron-like pattern oriented to reduce stent slippage, or the micropattern coating may be applied only to the flared portion, central region, or distal portion. Additionally, the micropattern coating layer may include combinations of dots, squares, stripes, spirals, etc.

[0065] FIG. 9 illustrates another exemplary stent 410. The stent 410 may be similar in form and function to the other exemplary stents described above. For example, the stent 410 may include an expandable scaffold (including one or more braided filaments 418 arranged to form the expandable scaffold) extending from a first end region 412 to a second end region 414. Additionally, the stent 410 may include a base coating 420 disposed along the expandable scaffold of the stent 410. Additionally, the stent 410 may include a micropattern coating layer 422 disposed along the base coating 420, such that the micropattern coating layer 422 extends along the entire length of the stent 410 and around the entire circumference of the stent 410. The micropattern coating layer 422 may be similar in form and function to the other micropattern coating layers disclosed herein. 9, the micropattern coating layer 422 may include a plurality of anti-slip elements 424 extending radially outward from the base of the micropattern coating layer 422. The anti-slip elements 424 may be designed to provide additional grip against the exterior surface of the stent 410.

[0066] Additionally, FIG. 9 illustrates the stent 410 in an unexpanded (e.g., pre-deployed) configuration. In other words, the stent 410 illustrated in FIG. 9 has a smaller outer diameter compared to the stent 410 in a deployed configuration (shown in FIG. 10). Furthermore, in some cases, it may be desirable to design the stent 410 to include one or more "preferential isolation regions" 426. In the example stent illustrated in FIG. 9, the individually spaced isolation regions 426 may extend longitudinally along the stent 410. For example, the micropattern coating layer 422 may include a plurality of discontinuous preferential isolation regions 426 spaced at desired intervals along the length and circumference of the stent 410.

[0067] It can be appreciated that the preferential separation region 426 may include strategically positioned holes, notches, slits, slots, channels, grooves, voids, or stress risers that allow one region of the micropattern coating layer 422 to move away from an adjacent region of the micropattern coating layer 422 as the stent 410 expands from a collapsed, pre-deployed configuration to an expanded, post-deployed configuration. In other words, the preferential separation region 426 may define a region along the stent 410 where a first portion of the micropattern coating layer 422 is designed to be separate and spaced apart from a second portion of the micropattern coating layer 422, with the preferential separation region 426 being positioned between the separated first and second portions of the micropattern coating 422. It can be appreciated that the preferential separation region 426 shown in FIG. 9 is positioned in a closed configuration because the stent 410 has not yet expanded from the collapsed configuration to the expanded configuration.

[0068] FIG. 9A shows a cross-sectional view taken along line 9A-9A in FIG. 9. FIG. 9A shows a base coating layer 420 surrounding each of the individual filaments 418. Additionally, FIG. 9A shows that the base coating layer 420 may extend across the cell openings of the stent 410. Additionally, FIG. 9A shows a micropattern coating layer 422 disposed on the base coating layer 420 (e.g., the micropattern coating layer 422 may be applied to the outer surface of the base coating 420). Additionally, the micropattern coating layer 422 may extend around the entire circumference of the stent 410 in the radially contracted configuration.

[0069] 9A further illustrates the micropattern coating layer 422 (including individual anti-slip elements 424) disposed along the base coating layer 420. Additionally, FIG. 9A illustrates the preferential separation regions 426 extending within the wall 438 of the micropattern coating layer 422 (e.g., extending radially inward from the outer surface of the micropattern coating layer 422). As shown in FIG. 9A, the preferential separation regions 426 may extend only partially within the wall 438 of the coating, such as extending through the micropattern coating layer 422 to the outer surface of the base coating layer 420. However, it is contemplated that in some instances, the preferential separation regions 426 may extend through only a portion of the thickness of the micropattern coating layer 422 or may extend into or through the base coating layer 420.

[0070] FIG. 10 illustrates the stent 410 after expansion from a collapsed configuration (shown in FIG. 9 ) to an expanded configuration. It can be appreciated that as the stent 410 expands, the micropattern coating layer 422 may be placed under stress due to the expansion force applied to the micropattern coating layer 422. For example, portions of the micropattern coating layer 422 may stretch and thus be placed under tension. As shown in FIG. 10 , one or more of the preferential separation regions 426 may open (e.g., separate) to relieve (e.g., relieve) the stress, thereby preventing the micropattern coating layer 422 from tearing in undesired locations and, conversely, allowing certain portions of the micropattern coating layer 422 to separate from one another. For example, the preferential separation regions 426 may separate adjacent portions of the micropattern coating layer 422 (e.g., separate one portion of the micropattern coating layer 422 from another portion of the micropattern coating layer 422), thereby allowing the stent 410 to more easily expand radially within a body lumen.

[0071] Figure 11 is a perspective view illustrating one of the exemplary preferential separation regions 426 shown in Figure 10. Note that for clarity, Figure 11 does not show the stent filaments 418 that may be positioned adjacent the separation regions 426. However, it can be understood that while the above description illustrates the separation regions 426 as being positioned within the cell openings of the stent (e.g., the spaces between the stent filaments 418), it is contemplated that the separation regions 426 may be positioned along any portion of the stent, including along the stent filaments 418.

[0072] 11 illustrates the preferential separation region 426 in the expanded configuration, where a first portion 432 of the micropattern coating layer 422 (disposed along the base coating 420 and including the individual anti-shear elements 424) is separated from a second portion 434 of the micropattern coating layer 422, leaving a preferential separation region 426 therebetween. The separation of the first portion 432 from the second portion 434 may create a void (e.g., an opening, hole, or the like) 436 extending through a wall 438 of the micropattern coating layer 422. However, it is contemplated that in some instances, the void 436 may extend through only a portion of the wall 438 of the micropattern coating layer 422. As shown in FIG. 11 , the base coating layer 420 may span the void 436 in the radially expanded configuration, thereby separating the void 436 from the lumen of the stent 410. The base coating layer 420 may be composed of a material that has greater elasticity than the material of the micropattern coating layer 422, such that the base coating layer 420 stretches more easily than the micropattern coating layer 422 as the first portion 434 separates from the second portion 434.

[0073] In some cases, the shape of the voids 436 may be different from the diamond shape shown in Figures 10 and 11. For example, the shape of the voids 436 may be circular, rectangular, oval, triangular, polygonal, any suitable geometric shape, or a combination thereof. Furthermore, in some cases, the separation regions 426 may be aligned such that they form perforations. In other words, the size, shape, and arrangement of the separation regions 426 may be such that perforations are created such that the coating 420 may tear along the perforations as the stent 410 expands (e.g., the voids tear sequentially one after the other).

[0074] FIG. 11A illustrates another exemplary stent 610. The stent 610 may be similar in form and function to the other exemplary stents described above. For example, the stent 610 may include an expandable scaffold (including one or more braided filaments 618 arranged to form the expandable scaffold) extending from a first end region 612 to a second end region 614. Additionally, the stent 610 may include a base coating layer 620 disposed along the expandable scaffold of the stent 610. Additionally, the stent 610 may include a micropattern coating layer 622 disposed along the base coating layer 620. In some cases, the base coating layer 620 may extend along the entire length of the stent 610 and around the entire circumference of the stent 610. The micropattern coating layer 622 may be similar in form and function to the other micropattern coating layers disclosed herein. For example, as shown in the detailed view of Figure 11A, the micropattern coating layer 622 may include a plurality of anti-slip elements 624 extending radially outward from the base of the micropattern coating layer 622. The anti-slip elements 624 may be designed to provide additional grip against the exterior surface of the stent 610.

[0075] Additionally, Figure 11A illustrates stent 610 in an unexpanded (e.g., radially contracted, radially constrained, pre-deployed) configuration. In other words, stent 610 illustrated in Figure 11A has a smaller outer diameter compared to stent 610 in its radially expanded, deployed configuration (shown in Figure 11C). In the radially contracted configuration, stent 610 has a longer axial length compared to the axial length of stent 610 in its radially expanded configuration.

[0076] Additionally, in some cases, it may be desirable to design the stent 610 to include one or more "preferential separation regions" 626. In the example stent shown in Figure 11A, the individually spaced apart separation regions 626 may be spaced longitudinally along the stent 610. For example, the micropatterned coating layer 622 may include a plurality of discontinuous preferential separation regions 626 spaced at desired intervals along the length and circumference of the stent 610.

[0077] It can be appreciated that the preferential separation regions 626 may include strategically positioned holes, notches, slits, slots, channels, grooves, voids, or stress risers that allow one region of the micropattern coating layer 622 to move relative to an adjacent region of the micropattern coating layer 622 as the stent 610 expands from a radially collapsed pre-deployed configuration to a radially expanded post-deployed configuration. It can be appreciated that the preferential separation regions 626 shown in FIG. 11A are positioned in an open configuration (e.g., resembling a diamond shape) when the stent 610 is in a radially collapsed, axially elongated configuration prior to radial expansion to the expanded configuration. In other words, the axial elongation of the stent 610 may open the preferential separation regions 626, separating portions of the micropattern coating layer 622 on either side of the preferential separation regions 626.

[0078] Figure 11B is a perspective view illustrating one of the exemplary preferential separation regions 626 shown in Figure 11A. Note that for clarity, Figure 11B does not show the stent filaments 618 that may be positioned adjacent the separation regions 626. However, although the above description illustrates the separation regions 626 as being positioned within the cell openings of the stent (e.g., the spaces between the stent filaments 618), it can be understood that it is contemplated that the separation regions 626 may be positioned along any portion of the stent 610, including along the stent filaments 618.

[0079] 11B illustrates the preferential separation region 626 when the stent 610 is in a radially collapsed configuration, with a first portion 632 of the micropattern coating layer 622 (disposed along the base coating 620 and including the individual anti-shear elements 624) separated from a second portion 634 of the micropattern coating layer 622, leaving a preferential separation region 626 therebetween. The separation of the first portion 632 from the second portion 634 may create a void (e.g., an opening, hole, or the like) 636 extending entirely through the wall of the micropattern coating layer 622. However, it is contemplated that in some instances, the void 636 may extend only partially through the wall of the micropattern coating layer 622. As shown in FIG. 11B, the base coating layer 620 may extend across the void 636 in the radially collapsed configuration, thereby separating the void 636 from the lumen of the stent 610. The base coating layer 620 may be composed of a material that has greater elasticity than the material of the micropattern coating layer 622, such that the base coating layer 620 stretches more easily than the micropattern coating layer 622 as the first portion 634 separates from the second portion 634.

[0080] In some cases, the shape of void 636 may be different from the diamond shape shown in Figure 11B. For example, the shape of void 636 may be circular, rectangular, oval, triangular, polygonal, any suitable geometric shape, or a combination thereof.

[0081] 11C illustrates the stent 610 after radial expansion from a radially collapsed configuration (shown in FIG. 11A) to a radially expanded configuration. It can be seen that as the stent 610 shifts from the collapsed configuration to the expanded configuration, the stent 610 contracts axially, shortening its axial length, which can close the separation regions 626 and bring portions of the micropattern coating layer 622 on either side of the preferential separation regions 626 closer together. This can result in the micropattern coating layer 622 extending substantially continuously across the outer surface of the stent 610. As shown in FIG. 11C, the preferential separation regions 626 can be aligned perpendicular to the longitudinal axis of the stent 610 and extend circumferentially when in the closed configuration. Thus, the circumferential ends of the preferential separation regions 626 may move apart as the stent 610 transitions from a radially collapsed, axially elongated configuration to a radially expanded, axially contracted configuration, and / or the axial ends of the preferential separation regions 626 may move closer together as the stent 610 transitions from a radially collapsed, axially elongated configuration to a radially expanded, axially contracted configuration. Thus, the circumferential ends of the preferential separation regions 626 may move closer together as the stent 610 transitions from a radially expanded, axially contracted configuration to a radially collapsed, axially elongated configuration, and / or the axial ends of the preferential separation regions 626 may move apart as the stent 610 transitions from a radially expanded, axially contracted configuration to a radially collapsed, axially elongated configuration.

[0082] FIG. 12 illustrates another exemplary stent 510. The stent 510 may be similar in form and function to the other exemplary stents described above. For example, the stent 510 may include an expandable scaffold (including one or more braided filaments 518 arranged to form the expandable scaffold) extending from a first end region 512 to a second end region 514. Additionally, the stent 510 may include a base coating 520 disposed along the expandable scaffold of the stent 510. Additionally, the stent 510 may include a micropattern coating layer 522 disposed along the base coating layer, such that the micropattern coating layer 522 extends along the entire length of the stent 510 and around the entire circumference of the stent 510. The micropattern coating layer 522 may be similar in form and function to the other micropattern coating layers disclosed herein. For example, as shown in detail in Figure 12, the micropattern coating layer 522 may include a plurality of anti-slip elements 524 extending radially outward from the base of the micropattern coating layer 522. The anti-slip elements 524 may be designed to provide additional grip against the exterior surface of the stent 510.

[0083] Additionally, FIG. 12 illustrates the stent 510 in an unexpanded (e.g., pre-deployed) configuration. In other words, the stent 510 illustrated in FIG. 12 has a smaller outer diameter compared to the stent 510 in a deployed configuration (shown in FIG. 13). Additionally, similar to that described above, in some cases it may be desirable to design the stent 510 to include one or more preferential separation regions 526. However, in the example stent illustrated in FIG. 12, the separation regions 526 may comprise longer, continuous, linear "strips" extending along the longitudinal axis of the stent 510. In some cases, each preferential separation region 526 extends the entire length of the micropattern coating layer 522, which in some cases may be along the entire length of the stent 510.

[0084] For example, it can be understood that the preferential separation region 526 can include strategically positioned linear slits, channels, grooves, or stress concentrations that allow one region of the micropattern coating layer 522 to move away from an adjacent region of the micropattern coating layer 522 as the stent 510 expands from a collapsed, pre-deployed configuration to an expanded, post-deployed configuration. In other words, the preferential separation region 526 can define a region along the stent 510 where a first portion of the micropattern coating layer 522 is designed to be separate and spaced apart from a second portion of the micropattern coating layer 522, with the preferential separation region 526 positioned between the separate first and second portions of the micropattern coating 522. It can be understood that the preferential separation region 526 shown in FIG. 12 is positioned in a closed configuration because the stent 510 has not yet expanded from the collapsed configuration to the expanded configuration.

[0085] FIG. 12A shows a cross-sectional view taken along line 12A-12A in FIG. 12. FIG. 12A shows a base coating layer 520 surrounding each of the individual filaments 518. Additionally, FIG. 12A shows that the base coating layer 520 may extend across the cell openings of the stent 510. Additionally, FIG. 12A shows a micropattern coating layer 522 disposed on the base coating layer 520 (e.g., the micropattern coating layer 522 may be applied to the outer surface of the base coating layer 520). Additionally, the micropattern coating layer 522 may extend around the entire circumference of the stent 510 in the radially contracted configuration.

[0086] 12A further illustrates the micropattern coating layer 522 (including individual anti-slip elements 524) disposed along the base coating layer 520. Additionally, FIG. 12A illustrates the preferential separation regions 526 extending within the wall 538 of the micropattern coating layer 522 (e.g., extending radially inward from the outer surface of the micropattern coating layer 522). As shown in FIG. 12A, the preferential separation regions 526 may extend only partially within the wall 538 of the coating, such as extending through the micropattern coating layer 522 to the outer surface of the base coating layer 520. However, it is contemplated that in some instances the preferential separation regions 526 may extend through only a portion of the thickness of the micropattern coating layer 522 or may extend into or through the base coating layer 520.

[0087] 13 illustrates the stent 510 after expansion from a collapsed configuration (shown in FIG. 12) to an expanded configuration. As discussed above, it can be appreciated that as the stent 510 expands, the micropattern coating layer 522 may be placed under stress due to the expansion forces applied to the micropattern coating layer 522. Thus, similar to the method described above with reference to FIGS. 9-11, adjacent portions of the micropattern coating layer 522 may separate along preferential separation regions 526, thereby creating longitudinal channels 528 along the stent surface, within which portions of the base coating layer 520 are exposed between the separated longitudinal strips of the micropattern coating layer 522.

[0088] 13 (and as described above), one or more of the preferential separation regions 526 may open (e.g., separate) to relieve (e.g., reduce) stresses imparted by stent deployment forces, thereby preventing micropattern coating layer 522 from tearing in undesired locations and, conversely, allowing predetermined portions of micropattern coating layer 422 to separate from one another. For example, preferential separation regions 526 may separate adjacent portions of micropattern coating layer 522 (e.g., separating one portion of micropattern coating layer 522 from another portion of micropattern coating layer 522), thereby allowing stent 410 to more easily radially expand within a body lumen.

[0089] FIG. 13A shows a cross-sectional view taken along line 13A-13A of FIG. 13. As discussed above, FIG. 13A shows stent 510 in an expanded configuration. FIG. 13A shows base coating layer 520 surrounding each of the individual filaments 518. Additionally, FIG. 13A shows that base coating layer 520 may extend across the cell openings of stent 510. Additionally, FIG. 13A shows micropattern coating layer 522 disposed on base coating 520 (e.g., micropattern coating layer 522 may be applied to the outer surface of base coating 520).

[0090] 13A further illustrates the micropattern coating layer 522 (including individual anti-shear elements 524) disposed along the base coating 520. Additionally, FIG. 13A illustrates the micropattern coating layer 522 expanded along the preferential separation regions 526, which form expanded “channels” 528 exposing the base coating layer 520 between separate portions (e.g., longitudinal strips) of the micropattern coating layer 522 that have moved away from or separated from one another. In other words, as the micropattern coating layer 522 expands, portions of the micropattern coating layer 522 separate from adjacent portions of the micropattern coating layer 522, creating channels 528 along the preferential separation regions 526. As shown in FIG. 13A , the base coating layer 420 may extend across the channels 528 in its radially expanded configuration, thereby separating the channels 528 from the lumen of the stent 510. The base coating layer 520 may be composed of a material having greater elasticity than the material of the micropattern coating layer 522, such that the base coating layer 520 stretches more easily than the micropattern coating layer 522 as the first longitudinal strip of the micropattern coating layer 522 separates from the second longitudinal strip of the micropattern coating layer 522.

[0091] 12-13A illustrate the preferential separation regions 526 as being straight longitudinal strips extending along the entire length (or a portion of the entire length) of the stent 510, it can be understood that the preferential separation regions 526 can include other configurations along the stent 510. For example, the separation regions 526 can extend along the stent 510 in a helical configuration.

[0092] As discussed above, it can be appreciated that any of the micropattern coating layers described herein can be configured to prevent longitudinal displacement or slippage of a stent described herein relative to the inner surface of a body lumen when the stent is positioned adjacent to a target site (e.g., adjacently disposed within the esophagus or intestine). In some cases, the micropattern coating layer can include a variety of different textures based on the specific design and / or size of the anti-shearing elements. For example, the surface texture can include points, spikes, spurs, ribs, bumps, ridges, protrusions, etc., which can be configured to protrude along, partially into, and / or through, or otherwise engage the wall of the body lumen, thereby providing a degree of interaction (e.g., surface friction, mechanical interlocking, interface, engagement, etc.) between the micropattern coating layer and tissue of the body lumen (e.g., the esophagus or intestine). The textured surface of the micropattern coating layer may engage with the tissue of the body lumen, thereby initially preventing longitudinal displacement or slippage of the stent relative to the body lumen upon implantation within the body lumen. The composition of the micropattern coating layer (including the surface texture) may create friction and / or adhesion with the tissue of the body lumen (e.g., the inner surface of the esophagus or intestine), thereby preventing longitudinal displacement or slippage of the stent relative to the body lumen. For example, in some cases, the surface texture may be designed to "grab" the inner surface of the body lumen.

[0093] Materials that may be used for the various components of any of the stents disclosed herein may include materials commonly associated with medical devices, although this is not intended to limit the materials to those disclosed herein. Rather, materials that may be used for the various components of any of the stents disclosed herein may include metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, and the like, or other suitable materials. Some examples of suitable polymers are polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® from DuPont), polyether block esters, polyurethanes (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyetheresters (e.g., ARNITEL® from DSM Engineering Plastics), ether or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalates and / or other polyester elastomers such as HYTREL® from DuPont), polyamides (e.g., DURETHAN® from Bayer or Elf Atochem® from Bayer).CRISTAMID™ from Atochem), elastomeric polyamides, block polyamide / ethers, polyether block amides (PEBA, available, for example, under the trademark PEBAX™), ethylene vinyl acetate copolymers (EVA), silicone, polyethylene (PE), MARLEX™ high density polyethylene, MARLEX™ low density polyethylene, linear low density polyethylene (e.g., REXELL™), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR™), polysulfone, nylon, nylon 12 (EMS American Grillon, Inc.), The sheath may be made of any suitable material, including but not limited to, GRILAMID® from Grilon, 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, or other suitable materials, or blends, combinations, copolymers, and polymer / metal composites thereof. In some embodiments, the sheath can be blended with a liquid crystal polymer (LCP). For example, the blend can contain up to about 6 percent LCP.

[0094] Some examples of suitable metals and metal alloys are stainless steels such as 304V, 304L, and 316LV stainless steel, mild steel, nickel-titanium alloys such as linear elastic and / or superelastic Nitinol, nickel-chromium-molybdenum alloys (such as UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY® C-22®, UNS: N10276 such as HASTELLOY® C276™, and other HASTELLOY® alloys), nickel-copper alloys (such as UNS: N04400 such as MONEL® 400, NICKELVAC™ 400, and NICORROS® 400), nickel-cobalt-chromium-molybdenum alloys (such as UNS: R30035 such as MP35-N™), nickel-molybdenum alloys (such as HASTELLOY® ALLOY B2™), other nickel alloys such as other nickel chromium alloys, other nickel molybdenum alloys, other nickel cobalt alloys, other nickel iron alloys, other nickel copper alloys, and other nickel tungsten or tungsten alloys, cobalt chromium alloys, cobalt chromium molybdenum alloys (e.g., UNS:R30003 such as ELGILOY® and PHYNOX®), platinum enriched stainless steel, titanium, combinations thereof, or any other suitable material.

[0095] In at least some embodiments, various components of the stents described herein may include radiopaque materials, such as by being doped with or composed of a radiopaque material. A radiopaque material is understood to be a material capable of producing a relatively bright image on a fluoroscopy screen or through which another imaging technique can be implemented during a medical procedure. This relatively bright image aids a user in determining the location of the various components of the stents described herein. Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, and polymeric materials loaded with radiopaque fillers. Additionally, other radiopaque marker bands and / or coils may be incorporated into the design of the various components of the stents described herein to achieve the same results.

[0096] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is imparted to various components of the stents described herein. For example, various components of the described stents may be constructed of materials that do not substantially distort images and do not produce substantial artifacts (e.g., gaps in images). For example, certain ferromagnetic materials may not be suitable because they may produce artifacts in MRI images. Various components of the stents described herein may be constructed of materials that can be imaged by MRI machines. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY® and PHYNOX®), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, such as MP35-N™), and nitinol.

[0097] It should be understood that this disclosure is, in many respects, merely illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps, without departing from the scope of the disclosure. This may include, to the extent appropriate, using any of the features of one illustrative embodiment in other embodiments. The scope of the disclosure will, of course, be defined by the language in which the appended claims are expressed. The technical ideas included in the present disclosure are described below. (Appendix 1) an expandable scaffold including a first end region, a second end region opposite the first end region, and an outer surface, the expandable scaffold configured to shift from a radially collapsed state to a radially expanded state; a coating disposed along the outer surface of the expandable scaffold, at least a portion of the coating comprising a plurality of anti-shear members, the coating further comprising a region of preferential separation, the region of preferential separation positioned between a first region of the coating and a second region of the coating; the preferential separation region is configured to allow the first region of the coating to separate from the second region of the coating along the preferential separation region therebetween as the expandable scaffold shifts from the radially collapsed state to the radially expanded state. A medical stent for treating a body lumen. (Appendix 2) 2. The medical stent of claim 1, wherein the region of preferential separation is configured to prevent the coating from separating from the outer surface of the expandable scaffold when the expandable scaffold shifts from the radially collapsed state to the radially expanded state. (Appendix 3) 3. The medical stent of claim 1 or 2, wherein separation of the first region of the coating from the second region of the coating creates holes in the coating along the preferential separation regions. (Appendix 4) 4. The medical stent of claim 3, wherein the pores extend through the wall of the coating. (Appendix 5) 4. The medical stent of claim 3, wherein the pores extend through only a portion of the wall of the coating. (Appendix 6) 4. A medical stent according to any one of claims 1 to 3, further comprising a plurality of holes disposed within the coating, the plurality of holes being aligned along the longitudinal axis of the stent. (Appendix 7) 7. The medical stent of claim 6, wherein the alignment of the plurality of holes in the preferential separation region creates a perforated preferential separation region. (Appendix 8) 8. The medical stent of claim 7, wherein the preferential separation region extends continuously along the longitudinal axis of the stent from the first end region to the second end region. (Appendix 9) 9. The medical stent of claim 7 or 8, wherein the preferential separation regions extend linearly along the longitudinal axis of the stent. (Appendix 10) 9. The medical stent of claim 7 or 8, wherein the regions of preferential separation extend non-linearly along the longitudinal axis of the stent. (Appendix 11) 11. The medical stent of any one of claims 1 to 10, wherein the expandable scaffold comprises a plurality of braided filaments arranged to define a plurality of cells therebetween, and wherein the region of preferential separation is positioned within one of the cells. (Appendix 12) an expandable scaffold including a first end region, a second end region opposite the first end region, and an outer surface, the expandable scaffold configured to shift from a radially collapsed state to a radially expanded state; a coating disposed along the outer surface of the expandable scaffold, at least a portion of the coating including a plurality of anti-shear members disposed thereon; the coating further comprises a plurality of preferential separation regions, each of the preferential separation regions spaced apart from one another, and each of the preferential separation regions configured to define a hole in the coating when the expandable scaffold shifts from the radially collapsed state to the radially expanded state. A medical stent for treating a body lumen. (Appendix 13) 13. The medical stent of claim 12, wherein each of the preferential separation regions is positioned between the first region of the coating and the second region of the coating, and each of the preferential separation regions is configured to allow the first region of the coating to separate from the second region of the coating along a respective preferential separation region therebetween as the expandable scaffold shifts from the radially collapsed state to the radially expanded state. (Appendix 14) 14. The medical stent of claim 12 or 13, wherein each of the plurality of preferential separation regions is configured to prevent the coating from separating from the outer surface of the expandable scaffold when the expandable scaffold shifts from the radially collapsed state to the radially expanded state. (Appendix 15) 15. The medical stent of any one of claims 12 to 14, wherein the pores in each of the preferential separation regions extend entirely through the wall of the coating.

Claims

1. An implantable stent having anti-slip properties, an expandable scaffold formed by one or more braided filaments extending from a first end region to a second end region, the braided filaments defining a plurality of cell openings therebetween, the expandable scaffold configured to shift from a radially collapsed state to a radially expanded state; a base coating layer disposed along the expandable scaffold, the base coating layer surrounding each filament and extending across the plurality of cell openings in both the radially collapsed state and the radially expanded state; a micropattern coating layer disposed on an outer surface of the base coating layer, the micropattern coating layer including individual elongated strips spaced apart by elongated channels, the base coating layer being exposed between adjacent elongated strips of the micropattern coating layer when the expandable scaffold shifts to the radially expanded state, at least a portion of the micropattern coating layer including a plurality of anti-shear members and including a wall. Implantable stents.

2. An implantable stent as described in claim 1, wherein the micropatterned coating layer extends around the entire circumference of the expandable scaffold in the radially collapsed state.

3. An implantable stent as described in claim 1 or 2, wherein the micropatterned coating layer extends along the entire length of the expandable scaffold.

4. An implantable stent as described in any one of claims 1 to 3, wherein the elongated channel extends longitudinally along the entire length of the expandable scaffold.

5. An implantable stent as described in any one of claims 1 to 4, wherein the micropattern coating layer includes one or more linear slits, channels, or grooves configured to separate the micropattern coating layer into the individual elongated strips when the expandable scaffold is in the radially expanded state.

6. An implantable stent as described in any one of claims 1 to 5, wherein the elongated channel extends continuously along the longitudinal axis of the expandable scaffold from the first end region to the second end region.

7. An implantable stent as described in any one of claims 1 to 6, wherein the micropattern coating layer includes a plurality of preferential separation regions extending within the wall portion of the micropattern coating layer, each preferential separation region being positioned between a first region of the micropattern coating layer and a second region of the micropattern coating layer, each preferential separation region being configured to enable the first region of the micropattern coating layer to separate from the second region of the micropattern coating layer along the preferential separation region therebetween, and generating one of the elongated channels between the first region and the second region as the expandable scaffold shifts from the radially collapsed state to the radially expanded state.

8. An implantable stent as described in claim 7, wherein each preferential separation region extends linearly along the longitudinal axis of the expandable scaffold.

9. An implantable stent as described in claim 7 or 8, wherein the preferential separation region extends continuously along the longitudinal axis of the expandable scaffold.

10. An implantable stent as described in claim 7, wherein each preferential separation region extends spirally along the expandable scaffold.

11. An implantable stent as described in any one of claims 7 to 10, wherein the preferential separation region extends through only a portion of the thickness of the micropatterned coating layer.

12. An implantable stent as described in any one of claims 1 to 11, wherein the base coating layer is formed from a material having greater elasticity than the material forming the micropattern coating layer.

13. An implantable stent having anti-slip properties, an expandable scaffold formed by one or more braided filaments extending from a first end region to a second end region, the braided filaments defining a plurality of cell openings therebetween, the expandable scaffold configured to shift from a radially collapsed state to a radially expanded state; a base coating layer disposed along the expandable scaffold, the base coating layer surrounding each filament and extending across the plurality of cell openings in both the radially collapsed state and the radially expanded state; a micropattern coating layer overlying an outer surface of the base coating layer, the micropattern coating layer extending around the entire circumference of the expandable scaffold when the expandable scaffold is in the radially collapsed state, and the micropattern coating layer being separated into a plurality of individual longitudinal strips spaced apart by longitudinal channels, the base coating layer being exposed between adjacent longitudinal strips of the micropattern coating layer when the expandable scaffold shifts to the radially expanded state, the longitudinal channels extending along an entire length of the expandable scaffold between the first end region and the second end region, and at least a portion of the micropattern coating layer including a plurality of anti-shear members. Implantable stents.

14. An implantable stent as described in claim 13, wherein the micropattern coating layer includes a plurality of preferential separation regions extending within a wall portion of the micropattern coating layer, each preferential separation region being positioned between a first region of the micropattern coating layer and a second region of the micropattern coating layer, each preferential separation region being configured to enable the first region of the micropattern coating layer to separate from the second region of the micropattern coating layer along the preferential separation region therebetween, and generating one of the longitudinal channels between the first region and the second region as the expandable scaffold shifts from the radially collapsed state to the radially expanded state.

15. An implantable stent as described in claim 14, wherein each of the plurality of preferential separation regions extends through only a portion of the thickness of the micropattern coating layer and extends continuously along the longitudinal axis of the expandable scaffold.

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