Scaffold comprising anti-shift ability

Abstract

A medical device, such as a medical stent, for treating a body lumen includes an expandable stent structure configured to transition from a radially collapsed state to a radially expanded state. The stent includes a coating disposed along an outer surface of the expandable stent structure, wherein a portion of the coating includes a plurality of anti-migration members and one or more preferential separation zones. Each preferential separation zone is configured to allow a first zone and a second zone of the coating to separate from one another along the preferential separation zone therebetween as the expandable stent structure transitions from the radially collapsed state to the radially expanded state.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 927,391, filed October 29, 2019, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to medical devices, methods for manufacturing medical devices, and uses thereof. More particularly, the present disclosure relates to expandable stents having anti-migration capabilities and examples of methods for their manufacture and use. BACKGROUND

[0004] Implantable medical devices, such as expandable stents, can be designed for treating a stricture in a body lumen and / or providing a fluid passageway for the flow of digestive matter, blood, or other fluids therethrough after a medical procedure. For example, some medical devices can include radially expandable or self-expanding stents that can be transluminally implanted via an endoscope or stent delivery device. Further, some stents can be implanted in a variety of body lumens, such as the esophagus, gastrointestinal tract (including the intestine, stomach, and colon), tracheobronchial, urethra, biliary tract, vasculature, and the like.

[0005] In some cases, it can be desirable to design a stent to have sufficient flexibility while maintaining sufficient radial force to keep the body lumen open at the treatment site. However, in some stents, the compressible and flexible properties that facilitate stent delivery can also create a stent that has a tendency to migrate from its initial deployed position after deployment. For example, a stent designed for positioning in the esophagus or gastrointestinal tract can have a tendency to migrate due to peristalsis (i.e., involuntary contractions and relaxations of the muscles of the esophagus, intestine, and colon that propel the contents of the conduit therethrough). Further, the esophagus, intestine, colon, and the like are generally moist and inherently slippery environments that further contribute to the tendency of a stent to migrate when deployed therein. One method of reducing stent migration can include exposing bare metal portions of the stent to the tissue of the body lumen. This stent structure can provide a structure that promotes tissue ingrowth into the voids or openings thereof. Tissue ingrowth can secure the stent in place and reduce the risk of stent migration.

[0006] Further, while it is important to design a stent that reduces the extent 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. Once tissue has fixed the stent in the body lumen, a stent that includes exposed portions (i.e., uncovered portions) designed to promote tissue ingrowth (e.g., to reduce stent migration, as described above) can also be more difficult to remove. Further, it is also important to design a stent that is convenient to load and deploy from a stent delivery device. One method of reducing stent stiffness and increasing radial deployment force can include reducing thickness, and thus the overall volume of a coating (e.g., an anti-migration coating) applied to the stent. Thus, in some cases, it can be desirable to design a coated stent that includes both anti-migration capabilities and reduced overall volume. Examples of medical devices having coatings that include both anti-migration capabilities and reduced volume are disclosed herein. SUMMARY

[0007] The present disclosure provides design, material, manufacturing method, and use alternatives for medical devices. An exemplary medical stent for treating a body lumen includes an expandable stent structure including a first end region, a second end region opposite the first end region, and an outer surface, wherein the expandable stent structure is configured to transition from a radially collapsed state to a radially expanded state. The stent also includes a coating disposed along the outer surface of the expandable stent structure. At least a portion of the coating includes a plurality of anti-migration members. The coating also includes a preferential separation region positioned between a first region of the coating and a second region of the coating. Further, 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 stent structure transitions from the radially collapsed state to the radially expanded state.

[0008] Alternatively, or in addition to, any of the above embodiments, wherein the preferential separation region is configured to prevent the coating from separating from the outer surface of the expandable stent structure as the expandable stent structure transitions from the radially collapsed state to the radially expanded state.

[0009] Alternatively, or in addition to, any of the above embodiments, wherein the separation of the first region of the coating from the second region of the coating forms an aperture in the coating along the preferential separation region.

[0010] Alternatively, or in addition to, any of the above embodiments, wherein the aperture extends completely through a wall of the coating.

[0011] Alternatively, or in addition to, any of the above embodiments, wherein the aperture extends only through a portion of a wall of the coating.

[0012] Alternatively, or in addition to, any of the above embodiments, further comprising a plurality of apertures disposed within the coating, wherein the plurality of apertures are aligned along a longitudinal axis of the stent.

[0013] Alternatively, or in addition to any of the above embodiments, wherein the alignment of the plurality of apertures of the preferential detachment zone forms a holed preferential detachment zone.

[0014] Alternatively, or in addition to any of the above embodiments, wherein the preferential detachment zone extends continuously along the longitudinal axis of the stent from the first end region to the second end region.

[0015] Alternatively, or in addition to any of the above embodiments, wherein the preferential detachment zone extends linearly along the longitudinal axis of the stent.

[0016] Alternatively, or in addition to any of the above embodiments, wherein the preferential detachment zone extends non-linearly along the longitudinal axis of the stent.

[0017] Alternatively, or in addition to any of the above embodiments, wherein the expandable stent structure comprises a plurality of interwoven filaments, and wherein the plurality of filaments are arranged to define a plurality of cells therebetween, and wherein the preferential detachment zone is positioned within one of the plurality of cells.

[0018] Another medical stent for treating a body lumen includes an expandable stent structure comprising a first end region, a second end region opposite the first end region, and an outer surface, wherein the expandable stent structure is configured to transition from a radially collapsed state to a radially expanded state. The stent further includes a coating arranged along the outer surface of the expandable stent structure, wherein at least a portion of the coating includes a plurality of anti-migration members arranged thereon. In addition, the coating includes a plurality of preferential detachment zones, each preferential detachment zone spaced apart from one another, and wherein each preferential detachment zone is configured to define an aperture in the coating when the expandable stent structure transitions from the radially collapsed state to the radially expanded state.

[0019] Alternatively, or in addition to any of the above embodiments, wherein each preferential detachment zone is positioned between a first region of the coating and a second region of the coating, and wherein each preferential detachment zone is configured to allow the first region of the coating to detach from the second region of the coating along the respective preferential detachment zone therebetween as the expandable stent structure transitions from the radially collapsed state to the radially expanded state.

[0020] Alternatively, or in addition to any of the above embodiments, wherein each preferential detachment zone of the plurality of preferential detachment zones is configured to prevent the coating from detaching from the outer surface of the expandable stent structure when the expandable stent structure transitions from the radially collapsed state to the radially expanded state.

[0021] Alternatively, or in addition to any of the above embodiments, wherein the aperture of each preferential detachment zone extends completely through a wall of the coating.

[0022] Alternatively or in addition to any of the above embodiments, wherein the orifice of each preferential separation zone extends only through a portion of the wall of the coating.

[0023] Alternatively or in addition to any of the above embodiments, wherein each preferential separation zone extends continuously along the longitudinal axis of the stent from the first end region to the second end region.

[0024] Alternatively or in addition to any of the above embodiments, wherein each preferential separation zone is spaced apart from one another along the longitudinal axis of the stent.

[0025] Alternatively or in addition to any of the above embodiments, wherein the expandable stent structure comprises a plurality of interwoven filaments, and wherein the plurality of filaments are arranged to define a plurality of cells therebetween, and wherein each preferential separation zone is positioned within a respective one of the plurality of cells.

[0026] Another medical stent includes an expandable stent structure comprising a first end region, a second end region opposite the first end region, and an outer surface, wherein the expandable stent structure is configured to transition from a radially collapsed state to a radially expanded state. Further, the expandable stent structure comprises a plurality of interwoven filaments defining a plurality of cell openings therebetween. Further, the stent includes a coating arranged along the outer surface of the expandable stent structure, wherein at least a portion of the coating includes a micropattern comprising a plurality of anti-migration members. Further, the micropattern is arranged to have the cell openings between the interwoven stent filaments.

[0027] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The details of BRIEF DESCRIPTION OF DRAWINGS

[0028] The present disclosure can be more completely understood in consideration of the following detailed description in connection with the following drawings, in which:

[0029] Figure 1 An exemplary stent including a coverage region is shown;

[0030] Figure 2 Another exemplary stent including a coverage region and a micropattern is shown;

[0031] Figure 3 A detailed view of a portion of the stent shown in FIG. 4 is shown; Figure 2 A cross-sectional view of the stent shown in FIG. 4 along line 4-4 is shown;

[0032] Figure 4 A detailed view of a portion of the stent shown in FIG. 4 is shown; Figure 2 A cross-sectional view of the stent shown in FIG. 4 along line 4-4 is shown;

[0033] Figure 5Another exemplary stent including a coverage zone and micro-pattern is shown;

[0034] Figure 6 Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 5 A detailed view of a portion of the stent shown in

[0035] Figure 7 Another exemplary stent including a coverage zone and micro-pattern is shown;

[0036] Figure 8 Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 7 A detailed view of a portion of the stent shown in

[0037] Figure 9 Another exemplary stent including a coverage zone and micro-pattern is shown;

[0038] Figure 9A Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 9 A cross-sectional view of the stent shown in

[0039] Figure 10 Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 9 The exemplary stent shown in

[0040] Figure 11 Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 10 A portion of the exemplary stent shown in

[0041] Figure 11A Another exemplary stent including a coverage zone and micro-pattern is shown;

[0042] Figure 11B Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 11A A portion of the exemplary stent shown in

[0043] Figure 11C Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 11A The exemplary stent shown in

[0044] Figure 12 Another exemplary stent including a coverage zone and micro-pattern is shown;

[0045] Figure 12A Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 12 A cross-sectional view of the stent shown in

[0046] Figure 13 Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 12 The exemplary stent shown in

[0047] Figure 13A Another exemplary stent including a coverage zone and micro-pattern is shown; Figure 13Cross-sectional view of the stent shown in FIG. 13 along line 13A-13A.

[0048] While the disclosure can take various modifications and alternative forms, specific details thereof have been disclosed with reference to the drawings and will be described in detail. It should be understood that the intention is not to limit the disclosure to the particular illustrative embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. DETAILED DESCRIPTION

[0049] As used in the following description, the terms "including", "includes", "containing", "contains", "having", "has", "a", "an", and "the" are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. As used in the following description, the terms "comprising", "comprises" and "comprised of" are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0050] All numerical values herein are assumed to be modified by the word "about" whether explicitly indicated or not. The word "about" generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the word "about" can include numbers that are rounded to the nearest significant figure.

[0051] The statement of a numerical range with endpoints includes all numbers within that range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0052] The singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. The word "or" as used in the claims is intended to mean "and / or" unless the context clearly indicates otherwise.

[0053] It should be noted that recitations of "one embodiment", "some embodiments”, "other embodiments” or the like do not necessarily all refer to the same embodiments. As such, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Additionally, the described features, structures, or characteristics can also be instantaneously eliminated from one or more embodiments without necessarily being recited therein.

[0054] The following detailed description should be read with reference to the drawings in which similar elements in different drawings are identified with like reference numerals. The drawings, which are not necessarily to scale, depict illustrative embodiments which are not intended to limit the scope of the disclosure.

[0055] As described above, implantable medical devices can be designed for treating a stricture in a body lumen and / or providing a fluid passageway for the flow of digestive matter, or other materials or fluids, therethrough after a traumatic medical procedure. The examples disclosed herein can include radially or self-expanding stents. These expandable stents can be transluminally implanted via an endoscope or another desired delivery device. Further, some stents can be implanted in a variety of body lumens, such as the esophagus, gastrointestinal tract (including the intestines and colon), airway, urethra, biliary tract (including the bile duct and / or pancreatic duct), vasculature, etc.

[0056] In some cases, it can be desirable to design a stent to include sufficient flexibility to conform to a tortuous body lumen while still delivering sufficient radial force to open the body lumen at the treatment site. However, in some stents, the compressible and flexible properties that facilitate stent delivery can also create a stent that has a tendency to migrate from its originally placed position. For example, a stent designed for positioning in the esophagus or intestines can have a tendency to migrate due to peristalsis (i.e., involuntary contraction and relaxation of the muscles of the esophagus, intestines, and colon that propel the contents of the conduit therethrough). Further, the generally wet and inherently slippery environment of the esophagus, intestines, colon, etc. further contributes to the tendency of a stent to migrate when placed therein.

[0057] Further, while it is important to design a stent that reduces the extent 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 placement. A stent that includes exposed portions (i.e., uncovered portions) designed to promote tissue ingrowth (e.g., to reduce stent migration, as described above) can also be more difficult to remove once tissue has fixed the stent in the body lumen. One method of reducing the force required to remove a stent from a body lumen can include covering a portion of the stent, thereby creating 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 fixed by tissue ingrowth). One method of reducing stent migration while maintaining the ability to remove and / or reposition the stent can include designing the outer surface of the stent to include a migration-resistant surface texture. For example, the stent structure of a stent can include a gripping structure (e.g., a micro-pattern gripping structure) that improves the surface friction of the stent. This improved surface friction can fix the stent in place and reduce the risk of stent migration. Exemplary medical devices including micro-pattern surface textures are discussed below.

[0058] Figure 1An exemplary implantable medical device, illustrated as a stent 110, is shown. However, although illustrated as a stent, the implantable medical device 110 can be any number of devices that can be introduced using an endoscope, subcutaneously, percutaneously, or by surgery to be positioned inside an organ, tissue, or lumen, such as an esophagus, intestine, colon, urethra, trachea, bronchus, bile duct, blood vessel, etc. The stent 110 can be configured to be positioned in a body lumen for a variety of medical applications. For example, the stent 110 can be used to treat a stenosis in a body lumen. In addition, the stent 110 can be used to provide a passageway for food or other digestive matter to pass therethrough without directly contacting adjacent tissue. It is contemplated that the examples described herein can be applied, for example, to the esophagus, as well as the gastrointestinal tract, blood vessels, urinary tract, bile duct, trachea bronchus, or renal duct. In some cases, the stent 110 (e.g., an intestinal stent, an esophageal stent, a vascular stent, a tracheal stent, a bronchial stent, etc.) can include an expandable stent structure.

[0059] The expandable stent structure of the stent 110 can 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 can extend to a first end of the stent 110, and the second end region 114 can extend to a second end of the stent 110 opposite the first end. The expandable stent structure of the stent can include an intermediate region 116 extending between the first end region 112 and the second end region 114, or positioned between the first end region 112 and the second end region 114 of the implantable medical device 110 to form an expandable tubular frame or stent structure having open ends and defining a lumen extending therethrough. As shown in Figure 1 As shown in FIG. 1, the first end region 112 and / or the second end region 114 can include a flared portion having an enlarged outer diameter greater than an outer diameter of the intermediate region 116, if desired, in the radially expanded configuration. For example, Figure 1 Both the first end region 112 and the second end region 114 are shown having an outer diameter greater than an outer diameter of the intermediate region 116 in the radially expanded configuration. In other embodiments, only one of the first end region 112 and the second end region 114 can include a flared portion, if desired, or the expandable stent structure of the stent 110 can have a constant outer diameter along its entire length.

[0060] The plurality of strut members 118 can be arranged in a variety of different designs and / or geometric patterns to form the expandable tubular framework or scaffold structure of the stent 110. Numerous designs, patterns, and / or configurations for stent cell openings (e.g., openings between adjacent strut members), strut thicknesses, strut designs, stent cell shapes are contemplated and can be applied to the embodiments described herein. Moreover, the self-expanding stent examples disclosed herein can include a stent having one or more strut members 118 that are combined to form a rigid and / or semi-rigid stent structure. In some examples disclosed herein, the strut members 118 that make up a set of a rigid / semi-rigid framework structure can be referred to as a scaffold. For example, the strut members 118 can be wires or filaments that are braided, knitted, intertwined, woven, knitted, crocheted, etc. to form the expandable scaffold structure or framework of the stent 110. The strut members (e.g., wires or filaments) 118 of the stent 110 can be configured to self-expand to an enlarged diameter when unconstrained. Alternatively, the strut members 118 can be comprised of a unitary structure (e.g., a cylindrical tubular member), such as a single cylindrical tubular laser cut nickel-titanium alloy tubular member, where the remaining portion of the tubular member comprises the strut members 118. The unitary structure of the stent 110 can be configured to self-expand to an enlarged diameter when unconstrained.

[0061] In at least some examples disclosed herein, the expandable scaffold structure of the stent 110 can be made of a variety of materials. For example, the expandable scaffold structure of the stent 110 can be made of a metal (e.g., nickel-titanium alloy). In other cases, the expandable scaffold structure of the stent 110 can be made of a polymeric material (e.g., polyethylene terephthalate (PET)). In yet other cases, the expandable scaffold structure of the stent 110 can be made of a combination of a metallic material and a polymeric material. Moreover, the expandable scaffold structure of the stent 110, or portions thereof, can include bioabsorbable and / or biodegradable materials.

[0062] As described above, in some cases, the stent 110 can include a coating 120 (represented by a dotted pattern in Figure 1 some examples) arranged along the expandable scaffold structure 118 of the stent 110. In some examples, the coating 120 can be referred to as a first or base coating. The base coating 120 can be applied to the expandable scaffold structure prior to the application of additional coatings, as will be described below. Although the base coating 120 is described as being applied to the expandable scaffold structure 118 of the stent 110, it is contemplated that the base coating 120 can be applied to any of the stent structures described herein. Figure 1The coating 120 is shown extending along the entire length and perimeter of the stent 110, but in some examples, the coating 120 can be disposed along only a portion of the stent 110. Further, the coating 120 can completely cover the stent 110, extending across or spanning the interstices (e.g., cell openings) between the struts 118 of the expandable framework or stent structure of the stent 110. In other words, the coating 120 can completely encase the expandable framework or stent structure of the stent 110 to completely seal the interstices of the expandable framework and thus prevent tissue ingrowth into the interior lumen of the stent 110. Although Figure 1 The coating 120 is shown extending along the outer surface of the strut members 118, but it is contemplated that the coating 120 can extend along the inner surface of the strut members 118 and / or can completely encase or encapsulate the strut members 118. Further, as will be discussed in greater detail below, the coating 120 can be applied by spraying, dipping, spin coating, or attaching a polymeric sheet or tube to the inner and / or outer surface of the stent wire 18.

[0063] In some cases, the coating 120 can comprise an elastic or non-elastic material. Further, a portion of the coating 120 can be comprised of a suitable material, such as a bio-stable material. For example, the coating 120 can comprise a polymeric material, such as silicone, polytetrafluoroethylene, polyurethane, etc., or other materials, including those disclosed herein. Further, a portion of the coating 120 can be a bio-stable material. For the purposes of the discussion herein, a bio-stable material can be defined as a material that does not undergo biodegradation. For example, the coating 120 can comprise a polymeric material, such as silicone, polytetrafluoroethylene, polyurethane, etc., or other materials, including those disclosed herein. In other examples, the coating 120 can be made of a fabric, PEEK (polyether ether ketone), ABS (acrylonitrile butadiene styrene polymer), PLS (polymer / layered silicate), or other suitable materials. Further, the coating 120 can comprise a 3D printed material.

[0064] As noted above, in some examples, it can be desirable to design the stent 110 to include one or more features (raised structures) that increase the surface friction of the stent 110. For example, Figure 2 In some examples, the coating of the stent 110 can include a micropatterned coating 122 comprised of a plurality of anti-migration elements in addition to or in place of the base coating 120. The following discussion will utilize the stent 110 of FIG. 1, but it is contemplated that the following discussion can be applied to other stent designs. Figure 3Detailed descriptions of the individual anti-migration elements that collectively make up the micro-patterned coating 122 are discussed in greater detail. The micro-patterned coating 122 can be designed to reduce stent migration while maintaining the ability to retrieve and / or reposition the stent 110. As described above and as will be described in greater detail below, the anti-migration elements that make up the micro-patterned coating 122 can include a plurality of non-slip structures (e.g., micro-patterned non-slip structures) that improve the surface friction of the stent 110.

[0065] Further, Figure 2 It is shown that the micro-patterned coating 122 can be arranged in a variety of arrangements along only select portions of the expandable stent structure of the stent 110 without being coated along the entire length and / or perimeter of the expandable stent structure of the stent 110. For example, Figure 2 It is shown that the micro-patterned coating 122 is arranged in a helical arrangement around the stent 110. In other words, the micro-patterned coating 122 is arranged in one or more or more helical bands that extend helically around the outer surface of the stent 110.

[0066] Figure 2 It is shown that the helical micro-patterned 122 extending along the stent 110 includes a helix pitch angle. However, it is to be appreciated that in other examples, the helix pitch angle of the micro-patterned coating 122 (making up one or more helical bands) can vary. In other words, other exemplary stent designs can include a micro-patterned coating 122 arranged in a helical form having a helix pitch angle that is greater or less than Figure 2 the helix pitch angle shown in FIG. 1.

[0067] Further, Figure 2 It is shown that the micro-patterned coating 122 extends from the first end region 112 (including the flared portion along the stent 110) to the second end region 114 (including the flared portion along the stent 110) of the stent 110. However, it is contemplated that the micro-patterned coating 122 can extend along any portion of the stent 110. For example, the micro-patterned coating 122 can be arranged along only the middle region 116. In other examples, the micro-patterned coating 122 can be arranged along the middle region 116 and one or more of the first end region 112 and / or the second end region 114 of the stent 110.

[0068] Figure 3 It is shown Figure 2 in greater detail. Figure 3 It is shown Figure 2 The micro-patterned coating 122 shown in FIG. 1 can be made up of a set (e.g., plurality) of individual anti-migration elements 124 extending from a base of the micro-patterned coating 122. Each of the anti-migration elements 124 can be spaced relatively close to one another, thereby collectively forming a surface texture or non-slip surface that reduces the likelihood of the stent 110 migrating when placed in a body lumen.

[0069] Figure 3 It is also shown that the individual anti-migration elements 124 can be shaped as cylinders (e.g., posts). However, it is contemplated that the individual anti-migration elements 124 can include a variety of shapes. For example, the individual anti-migration elements 124 can be circular, square, triangular, oval, polygonal, diamond shaped, posts, rectangular, spikes, hooks, any suitable geometric shape, or combinations thereof. Examples of other shapes of anti-migration elements 124 are disclosed in U.S. Patent Application No. US2013 / 0268063, the entirety of which is incorporated herein by reference.

[0070] In some examples, the micro-patterned coating 122 (including the anti-migration elements 124) can be formed by first depositing a material for the micro-patterned coating 122 onto the base coating 120 and then stamping the micro-patterned coating 122 to form the individual anti-migration elements 124 (e.g., stamping portions of the micro-patterned coating 122 to form individual anti-migration elements 124 that collectively form the micro-patterned coating 122). In some examples, the micro-patterned coating 122 can include a liquid silicone that is coated onto the base coating 120. For example, the liquid silicone can be layered onto a mold having a micro-pattern inlayed therein. After allowing the silicone layer to harden, it can be attached to the base coating 120 via another layer of liquid silicone (e.g., the layer of liquid silicone can be used to attach the molded micro-patterned silicone to the base coating 120). However, in other embodiments, the micro-patterned coating can be molded directly onto the base coating 120 or molded and then applied to the base coating 120.

[0071] Further, it is contemplated that in other examples, Figure 3 The anti-migration elements 124 shown in FIG. 1 can be formed by stamping the base coating 120. For example, in some cases, the anti-migration elements 124 can be formed by stamping portions of the base coating 120 to form individual anti-migration elements 124.

[0072] In yet other examples, the micro-patterned coating 122 (including the anti-migration elements 124) can 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 is contemplated that the sleeve can be shaped to include the micro-patterned coating 122 prior to being positioned and attached to the stent 110. For example, Figure 3 The sleeve including the micro-patterned coating 122 shown in FIG. 1 can be formed in a first manufacturing step (e.g., by molding), whereby the sleeve is then coupled to the outer surface of the stent 110 in a second manufacturing step.

[0073] Figure 4 A cross-sectional view of the stent 110 taken along line 4-4 is shown in FIG. 4. Figure 2 Figure 4 ​Stent filaments 118 are shown arranged around the longitudinal center axis 130 of the stent 110. Further, Figure 4 A base coat 120 is shown surrounding each individual filament 118. Further, Figure 4 The base coat 120 is shown as spanning the cell openings of the stent 110.

[0074] Further, Figure 4 The detailed view of the base coat 120, micro-patterned coating 122, and plurality of anti-migration members 124 is shown in cross-section. As shown in the detailed view of Figure 4 As shown in the detailed view of the base coat 120, the base coat 120 can have a thickness "X". In some examples, the thickness of the base coat 120 can be about 20-80 microns, or can be about 30-70 microns, or can be about 40-60 microns, or can be about 40-70 microns, or can be about 30-80 microns, or about 50 microns. Further, Figure 4 The detailed view of the base coat 120, micro-patterned coating 122, and plurality of anti-migration members 124 is shown in cross-section. As shown in the detailed view of

[0075] It will be appreciated that the thicker portions of the micro-patterned coating 122 (relative to the other, thinner portions of the base coating 120) can form an outwardly extending surface texture or gripping (anti-slip) surface that reduces the likelihood of the stent 110 shifting when placed in a body lumen, while the reduced thickness of the base coating 120 of the coating can allow the stent 110 to be radially collapsed and / or radially expanded with less resistance. It will be appreciated from the foregoing description that the addition of a micro-patterned coating (e.g., the micro-patterned coating 122) to the outer surface of an exemplary stent will increase the overall coating volume of the stent. It will be further appreciated that in some instances, this additional coating volume can increase the axial stiffness and / or radial deployment force of the stent (e.g., the stent 110). It will thus also be appreciated that coating the micro-patterned coating (e.g., the layer 122) along only some portions of the outer surface of the stent can reduce (e.g., decrease) the adverse effects associated with disposing a micro-patterned coating along the entire outer surface of the stent. In other words, it can be desirable to reduce the overall volume of the stent (and thereby increase the stent stiffness and radial deployment force) by coating the micro-patterned coating (e.g., the layer 122) along only select portions of the stent. Moreover, reducing the overall coating thickness of the stent can provide additional advantages when attempting to load the stent into a delivery device. For example, limiting the coating to multiple locations can not only reduce the overall volume of the coating, but can also help to maintain the mechanical properties of the stent (where the pre-shortening force and radial force are not substantially reduced), thereby allowing the stent to be compressed to a more reduced diameter and facilitating easier device of the stent into a stent delivery device.

[0076] Furthermore, Figure 4 It is shown that the anti-migration elements 124 can be disposed along the stent 110 such that the anti-migration elements 124 extend radially in a direction away from the strut members 118 of the expandable stent structure. As described above, the base coating 120 and / or the micro-patterned coating 122 can extend across the gaps or openings between adjacent struts 118. Moreover, Figure 4 It is shown that the micro-patterned coating 122 can be located at the outermost surface of the stent 110 such that it contacts the inner surface of the body lumen in which the stent 110 can be placed.

[0077] As Figure 4 It will be appreciated that the micro-patterned coating 122 can form a textured and / or roughened surface that is designed to contact and mate with the inner surface of the exemplary body lumen with which it is mated, as shown in FIG. 6. For example, in some cases, the textured micro-patterned coating 122 surface can temporarily secure the uncovered portions of the stent 110 along the inner surface of the exemplary body lumen.

[0078] Figure 5Another exemplary stent 210 is shown. The stent 210 can be similar in shape and function to the stent 110 described above. For example, the stent 210 can include an expandable stent structure (including one or more interwoven filaments 218 arranged to form the expandable stent structure) extending from a first end region 212 to a second end region 214. An intermediate region 216 can extend between the first end region 212 and the second end region 214. If desired, the first end region 212 and / or the second end region 214 can include a flared portion having an enlarged outer diameter that is greater than an outer diameter of the intermediate region 216 in a radially expanded configuration. In addition, the stent 210 can include a primer coating 220 arranged along the expandable stent structure of the stent 210.

[0079] Figure 5 It is also shown that a portion of the stent 210 can include a unique micro-pattern coating 222 formed of a plurality of anti-migration elements as described above. However, Figure 5 The micro-pattern coating 222 shown in the middle can be arranged in a "dot" pattern. In other words, the micro-pattern coating 222 can include a plurality of separate discrete regions (e.g., discrete blocks) of the coating that are spaced apart from other discrete separate regions (e.g., other discrete blocks) of the coating of the micro-pattern coating 222, where each discrete region of the micro-pattern coating 222 includes a plurality of anti-migration elements formed thereon. The discrete blocks of the micro-pattern coating 222 can be arranged along the length and / or circumference (or any portion) of the stent 210. Each region / block (e.g., region, portion, etc.) of anti-migration elements can be independent and spaced apart from one another. In addition, if desired, each region / block of anti-migration elements can be arranged in a desired shape, such as a circular shape (e.g., dot). The sum of all of the discrete regions of anti-migration elements can be referred to as the micro-pattern coating 222, as shown in the middle of Figure 5

[0080] In some examples, one or more of the "dots" of the micro-pattern coating 222 can be aligned with one another along the entire length (or portion thereof) of the stent 210. However, in other examples, the dots of the micro-pattern coating 222 can not be aligned with one another. Rather, the dots of the micro-pattern coating 222 can be arranged in a variety of patterns along the stent 210. In some examples, the dots of the micro-pattern coating 222 can be arranged in a random distribution.

[0081] In addition, Figure 5 The micro-pattern coating 222 is shown extending from the first end region 212 (including along the flared portion of the stent 210) to the second end region 214 (including along the flared portion of the stent 210). However, it is contemplated that the micro-pattern coating 222 can extend along any portion of the stent 210. For example, the micro-pattern coating 222 can be positioned along only the intermediate region 216 or along the intermediate region 216 and one or more of the first end region 212 and / or the second end region 214 of the stent 210.​

[0082] Figure 6 It shows Figure 5 The detailed view shown. As... Figure 3 , Figure 6 It shows Figure 3 The micropatterned coating 222 shown may include a row (e.g., a plurality) of individual anti-displacement elements 224 extending radially outward from the base of the micropatterned coating 222. Each anti-displacement element 224 may be spaced relatively close to each other, thereby collectively forming a surface texture or clamping surface that reduces the likelihood of displacement of the stent 210 when placed in a body cavity.

[0083] also, Figure 6 Multiple anti-displacement elements 224 are shown to be arranged to collectively form a circle (e.g., a "dot" of the dot micropatterned coating 222 described above). It is conceivable that the anti-displacement elements 224 can be formed in a manner similar to other micropatterned structures described herein. For example, Figure 6 The micropatterned coating 222 shown can be formed by covering a base coating 220 with a material for forming the micropatterned coating 222, and then stamping the micropatterned coating 222 into a separately formed anti-displacement element 224. Alternatively, the micropatterned coating 222 can be molded independently and then applied to the base coating 220. Furthermore, Figure 6 The micropatterned coating 222 shown can be arranged along any part of the support 210.

[0084] Figure 7 Another exemplary stent 310 is shown. This stent 310 may be similar in shape and function to the other radioactive stents described above. For example, this stent 310 may include an expandable stent structure (including one or more interlaced wires 318 arranged to form the expandable stent structure) extending from a first end region 312 to a second end region 314. An intermediate region 316 may extend between the first end region 312 and the second end region 314. If necessary, the first end region 312 and / or the second end region 314 may include flared portions having an enlarged outer diameter in a radially expanded configuration greater than the outer diameter of the intermediate region 316. Furthermore, the stent 310 may include an undercoat 320 arranged along the expandable stent structure of the stent 310.

[0085] Figure 7 It is also shown that a portion of the support 310 may be similar to the aforementioned element, including a unique micropatterned coating 322 composed of multiple anti-displacement elements. However, Figure 7The micro-patterned coating 322 shown in FIG. 3 can include a plurality of individual "diamond" patterns. In other words, the micro-patterned coating 322 can include a plurality of independent discrete regions (e.g., discrete blocks) of the coating that are spaced apart from other discrete independent regions (e.g., other discrete blocks) of the coating of the micro-patterned coating 322, where each discrete region of the micro-patterned coating 322 includes a plurality of anti-migration elements formed thereon. The discrete blocks of the micro-patterned coating 322 can be arranged along the length and / or circumference (or any portion) of the stent 310. Each region / block (e.g., region, portion, etc.) of anti-migration elements can be independent and spaced apart from one another. Further, each region / block of anti-migration elements can be arranged in a desired shape (e.g., diamond shape) as desired. The sum of all of the discrete regions of anti-migration elements can be referred to as the micro-patterned coating 322, as shown in FIG. 3. Figure 7

[0086] In some examples, one or more of the micro-patterned coating 322 "diamonds" can be aligned with one another along the entire length (or a portion thereof) of the stent 310. However, in other examples, the diamonds of the micro-patterned coating 322 can not be aligned with one another. Rather, the diamonds of the micro-patterned coating 322 can be arranged in a variety of patterns along the stent 310. In some examples, the diamonds of the micro-patterned coating 322 can be arranged in a random distribution.

[0087] Further, Figure 7 The micro-patterned coating 322 is shown extending from the first end region 312 (including the flared portion along the stent 310) to the second end region 314 (including the flared portion along the stent 310). However, it is contemplated that the micro-patterned coating 322 can extend along any portion of the stent 310. For example, the micro-patterned coating 322 can be positioned along only the middle region 316 or along the middle region 316 and one or more of the first end region 312 and / or the second end region 314 of the stent 310.

[0088] Figure 8 The detailed view shown in FIG. 3. Figure 7 The detailed view shown in FIG. 3. Figure 8 The detailed view shown in FIG. 3. Figure 7 The micro-patterned coating 322 shown in FIG. 3 can be comprised of an array (e.g., plurality) of independent anti-migration elements 324. Each anti-migration element 324 can be spaced very close to one another, thereby collectively forming a surface texture or gripping (anti-slip) surface, which reduces the likelihood of movement of the stent 310 when placed in a body lumen.

[0089] Further, Figure 8 The plurality of anti-migration elements 324 can be arranged to collectively comprise a diamond (e.g., one "diamond" of the micro-pattern 322 described above). It is contemplated that the anti-migration elements 324 can be formed in a manner similar to the other micro-patterns described herein. For example, Figure 8 ​The micropatterned coating 322 shown in FIG. 3 can be formed by covering the material used to form the micropatterned coating 322 over the base coating 320 and then stamping the micropatterned coating 322 into individually shaped anti-migration elements 324. Alternatively, the micropatterned coating 322 can be individually molded and then applied to the base coating 320. Furthermore, Figure 8 The micropatterned coating 322 shown in FIG. 3 can be disposed along any portion of the stent 310.

[0090] In some examples (such as the exemplary micropatterns described with respect to Figure 7 and Figure 8 , one or more individually diamond-shaped blocks collectively forming the micropatterned coating 322 can be positioned between adjacent filaments 318 of the stent 310. In other words, the micropatterned coating 322 can be formed such that each anti-migration element 324 is located in an area that is entirely between stent struts 318, thereby reducing the overall radial thickness of the stent 310 in the area having the micropatterned coating 322.

[0091] While the above examples described with respect to Figures 2-8 illustrate several different micropatterned coating arrangements, it will be appreciated that a wide variety of micropatterned coating arrangements can be envisioned. For example, the micropatterned coating can 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 micropatterned coating can include V-shaped line patterns oriented to reduce stent migration, or the micropatterned coating can be applied only on the flared portion, the mid-portion, or the distal portion. Furthermore, the micropatterned coating can include a combination of dots, squares, striped bands, spirals, etc.

[0092] Figure 9 Another exemplary stent 410 is shown. The stent 410 can be similar in shape and function to the other exemplary stents described above. For example, the stent 410 can include an expandable stent structure (including one or more interwoven filaments 418 arranged to form the expandable stent structure) extending from a first end region 412 to a second end region 414. Furthermore, the stent 410 can include a base coating 420 arranged along the expandable stent structure of the stent 410. In addition, the stent 410 can include a micropatterned coating 422 arranged along the base coating 420, whereby the micropatterned coating 422 extends along the entire length and around the entire circumference of the stent 410. The micropatterned coating 422 can be similar in shape and function to the other micropatterned coatings disclosed herein. For example, as shown in the detailed view of Figure 9 , the micropatterned coating 422 can include a plurality of anti-migration elements 424 extending radially outward from a base of the micropatterned coating 422. The anti-migration elements 424 can be designed to provide additional clamping force to the outer surface of the stent 410.

[0093] Furthermore,Figure 9 The bracket 410 is shown in an unexpanded (e.g., pre-placed) configuration. In other words, Figure 9 The bracket 410 shown is compared to the bracket 410 in the placement configuration (shown in...). Figure 10 It has a reduced outer diameter. Furthermore, in some cases, it is desirable to design the support 410 to include one or more "preferred separation zones" 426. Figure 9 In the illustrated support example, individually spaced separation regions 426 may extend longitudinally along the support 410. For example, the micropatterned coating 422 may include a plurality of discontinuous preferred separation regions 426 arranged at ideal intervals along the length and circumference of the support 410.

[0094] It is understood that the preferred separation region 426 may include strategically placed orifices, notches, slits, slots, channels, grooves, pores, or stress concentration devices that allow a region of the micropatterned coating 422 to move in a direction away from an adjacent region of the micropatterned coating 422 as the support 410 expands from a retracted pre-placed configuration to an expanded placement configuration. In other words, the preferred separation region 426 may define a region along the support 410 in which a first portion of the micropatterned coating 422 is designed to separate from and space itself from a second portion of the micropatterned coating 422, wherein the preferred separation region 426 is located between the separated first and second portions of the micropatterned coating 422. It is understood that... Figure 9 The priority separation zone 426 shown is in a closed configuration because the support 410 has not yet expanded from the contracted configuration to the expanded configuration.

[0095] Figure 9A It shows Figure 9 The sectional view taken along the line 9A-9A. Figure 9A The undercoating 420 surrounding each individual filament 418 is shown. Furthermore, Figure 9A The base coating 420 is shown to extend across the chamber opening of the support 410. Furthermore, Figure 9A A micropatterned coating 422 is shown disposed on the base coating 420 (e.g., the micropatterned coating 422 may be applied to the outer surface of the base coating 420). Furthermore, the micropatterned coating 422 may extend around the entire circumference of the support 410 in a radially contracted configuration.

[0096] also, Figure 9A A detailed view shows the micropatterned coating 422 (including individual anti-displacement elements 424) arranged along the base coating 420. Furthermore, Figure 9A A preferred separation region 426 is shown extending within the wall 438 of the micropatterned coating 422 (e.g., extending radially inward from the outer surface of the micropatterned coating 422). Figure 9AAs shown, the preferred separation region 426 may extend only partially through the wall 438 of the coating, such as through the micropatterned coating 422, to the outer surface of the base coating 420. However, it is also conceivable that in some instances, the preferred separation region 426 may extend only through a portion of the thickness of the micropatterned coating 422, or the preferred separation region 426 may extend into or through the base coating 420.

[0097] Figure 10 This shows the configuration that has been reduced from the collapsed configuration (shown in) Figure 9 The support 410 expands into its expanded configuration. It is understood that as the support 410 expands, the micropatterned coating 422 will be placed under stress due to the expansion force imparted to the micropatterned coating 422. For example, portions of the micropatterned coating 422 will stretch and thus be placed under tension. (As in...) Figure 10 As shown, openings (e.g., separation) in one or more preferred separation regions 426 can reduce (e.g., alleviate) this stress, thereby preventing the micropatterned coating 422 from tearing at undesirable locations, while allowing predetermined portions of the micropatterned coating 422 to separate from each other. For example, allowing the preferred separation regions 426 to separate adjacent portions of the micropatterned coating 422 (e.g., one part of the micropatterned coating 422 with another part of the micropatterned coating 422) can allow the stent 410 to expand radially more easily within the body cavity.

[0098] Figure 11 It shows Figure 10 A perspective view of one of the exemplary priority separation regions 426 shown. It should be noted that, for simplicity, Figure 11 The stent wire 418, which can be positioned adjacent to the separation zone 426, is not shown. However, it is understood that although the above description describes the separation zone 426 as being positioned in the stent chamber opening (e.g., in the space between the stent wires 418), it is conceivable that the separation zone 426 can be positioned along any part of the stent, including along the stent wires 418.

[0099] Figure 11 A preferred separation region 426 is shown in an expanded configuration, whereby a first portion 432 of the micropatterned coating 422 (arranged along the undercoat 420 and including various anti-displacement elements 424) has been separated from a second portion 434 of the micropatterned coating 422, with the preferred separation region 426 located between the first and second portions. This separation of the first portion 432 from the second portion 434 can form a pore (e.g., an opening, aperture, hole, etc.) 436 that extends completely through the wall 438 of the micropatterned coating 422. However, it is also conceivable that in some instances, the pore 436 may only extend through a portion of the wall 438 of the micropatterned coating 422. (As shown in...) Figure 11As shown, in the radial expansion configuration, the undercoat 420 can extend across the pore 436, thereby separating the pore 436 from the inner cavity of the support 410. The undercoat 420 can be made of a material with greater elasticity than the patterned coating 422 material, so that the undercoat 420 can be stretched more easily than the micropatterned coating 422 as the first part 434 separates from the second part 434.

[0100] In some cases, the shape of pore 436 may differ from... Figure 10 and Figure 11 The diamond shape shown is an example. For instance, the shape of the pores 436 can be circular, rectangular, oval, triangular, polygonal, any suitable geometry, or a combination thereof. Furthermore, in some cases, the separation regions 426 can be aligned so that they form eyelets. In other words, the size, shape, and arrangement of the separation regions 426 can form eyelets, thereby allowing the coating 420 to tear along the eyelets (e.g., successive tearing from one pore to another) as the support 410 expands.

[0101] Figure 11A Another exemplary support 610 is shown. Support 610 may be similar in shape and function to the other exemplary supports described above. For example, support 610 may include an expandable support structure (including one or more interwoven filaments 618 arranged to form the expandable support structure) extending from a first end region 612 to a second end region 614. Furthermore, support 610 may include a base coat 620 arranged along the expandable support structure of support 610. Additionally, support 610 may include a micropatterned coating 622 arranged along the base coat 620. In some cases, the base coat 620 may extend along its entire length and around the entire circumference of support 610. Micropatterned coating 622 may be similar in shape and function to other micropatterned coatings discussed herein. For example, as in... Figure 11A As shown in the detailed view, the micropatterned coating 622 may include a plurality of anti-displacement elements 624 extending radially outward from the base of the micropatterned coating 622. The anti-displacement elements 624 may be designed to provide additional clamping force to the outer surface of the support 610.

[0102] also, Figure 11A A support 610 is shown in an unexpanded (e.g., radially contracted, radially constrained, pre-positioned) configuration. In other words, Figure 11A The bracket 610 shown has a difference compared to the bracket 610 in the radially expanded configuration of placement (shown in Figure 11C The outer diameter is reduced. In the radially contracting configuration, the support 610 has an elongated axial length compared to the axial length of the support 610 in the radially expanding configuration.

[0103] Furthermore, in some cases, it can be desirable to design the stent 610 to include one or more "preferential detachment zones" 626. In Figure 11A In the stent example shown in FIG. 6B, each of the spaced-apart detachment zones 626 can be longitudinally spaced along the stent 610. For example, the micropatterned coating 622 can include a plurality of discrete preferential detachment zones 626 arranged at desired intervals along the length and circumference of the stent 610.

[0104] It will be appreciated that the preferential detachment zones 626 can include strategically placed apertures, notches, slits, slots, channels, grooves, porosities, or stress concentrators that allow a region of the micropatterned coating 622 to move relative to an adjacent region of the micropatterned coating 622 as the stent 610 expands from a radially collapsed, pre-deployed configuration to a radially expanded, deployed configuration. It will be appreciated that, prior to radially expanding to the expanded configuration, Figure 11A The preferential detachment zones 626 shown in FIG. 6B are in an open configuration (e.g., similar to a diamond shape) in which the stent 610 is in a radially collapsed and axially elongated configuration. In other words, the axial elongation of the stent 610 can cause the preferential detachment zones 626 to open, thereby allowing portions of the micropatterned coating 622 on one side of the preferential detachment zones 626 to move apart.

[0105] Figure 11B A perspective view of one of the exemplary preferential detachment zones 626 shown in FIG. 6B is shown in FIG. 6C. It should be noted that, for simplicity, Figure 11A A perspective view of one of the exemplary preferential detachment zones 626 shown in FIG. 6B is shown in FIG. 6C. It should be noted that, for simplicity, Figure 11B Stent wires 618 that can be located adjacent to the detachment zones 626 are not shown. However, it will be appreciated that, although the above description depicts the detachment zones 626 as being positioned in stent cell openings (e.g., spaces between stent wires 618), it is contemplated that the detachment zones 626 can be positioned along any portion of the stent 610, including along the stent wires 618.

[0106] Figure 11B A preferential detachment zone 626 is shown in which the stent 610 is in a radially collapsed configuration, whereby a first portion 632 of the micropatterned coating 622 (arranged along the undercoat 620 and including a plurality of individual anti-migration elements 624) is detached from a second portion 634 of the micropatterned coating 622, with the preferential detachment zone 626 being between the first and second portions. The detachment of the first portion 632 from the second portion 634 can form a porosity (e.g., an opening, aperture, hole, etc.) 636 that extends completely through the wall of the micropatterned coating 622. However, it is also contemplated that, in some examples, the porosity 636 can extend through only a portion of the wall of the micropatterned coating 622. As shown in FIG. 6D, the porosity 636 can be formed by the preferential detachment zone 626 opening to allow the first portion 632 to move apart from the second portion 634. Figure 11BIn the radially collapsed configuration, the undercoat 620 can extend across the aperture 636, isolating the aperture 636 from the lumen of the stent 610, as shown in FIG. 6B. The undercoat 620 can be composed of a material having greater elasticity than the material of the micro-patterned coating 622, such that the micro-patterned coating 622 stretches more easily than the undercoat 620 when the first portion 634 is separated from the second portion 634.

[0107] In some cases, the shape of the aperture 636 can be different than the diamond shape shown in FIG. 6A. For example, the shape of the aperture 636 can be circular, rectangular, oval, triangular, polygonal, any suitable geometric shape, or combinations thereof. Figure 11B

[0108] Figure 11C The stent 610 is shown after having been radially expanded from the radially collapsed configuration (shown in FIG. 6B) to a radially expanded configuration. From FIG. 6C, it can be appreciated that as the stent 610 is converted from the collapsed configuration to the expanded configuration, the stent 610 is axially shortened as it contracts axially, which can correspondingly cause the separation zone 626 to close, moving the portions of the micro-patterned coating 622 on either side of the preferential separation zone 626 together. This can result in the micro-patterned coating 622 extending substantially continuously across the outer surface of the stent 610. Figure 11A Figure 11C Figure 11C As shown in FIG. 6A, the preferential separation zone 626 can be aligned perpendicular to the longitudinal axis of the stent 610 and extend in the circumferential direction when in the open configuration. Thus, the circumferentially opposite ends of the preferential separation zone 626 can move apart when the stent 610 is converted from the radially collapsed, axially elongated configuration to the radially expanded, axially contracted configuration, and / or the axially opposite ends of the preferential separation zone 626 can move together when the stent 610 is converted from the radially collapsed, axially elongated configuration to the radially expanded, axially contracted configuration. Thus, the circumferentially opposite ends of the preferential separation zone 626 can move together when the stent 610 is converted from the radially expanded, axially contracted configuration to the radially collapsed, axially elongated configuration, and / or the axially opposite ends of the preferential separation zone 626 can move apart when the stent 610 is converted from the radially expanded, axially contracted configuration to the radially collapsed, axially elongated configuration.

[0109] Figure 12 ​​​Another exemplary stent 510 is shown. The stent 510 can be similar in shape and function to the other exemplary stents described above. For example, the stent 510 can include an expandable stent structure (which includes one or more interwoven filaments 518 arranged to constitute the expandable stent structure) extending from a first end region 512 to a second end region 514. Further, the stent 510 can include a base coat 520 arranged along the expandable stent structure of the stent 510. Further, the stent 510 can include a micro-patterned coat 522 arranged along the base coat, whereby the micro-patterned coat 522 extends along the entire length and around the entire circumference of the stent 510. The micro-patterned coat 522 can be similar in shape and function to the other micro-patterned coats disclosed herein. For example, as shown in the detailed view of Figure 12 As shown in the detailed view of

[0110] Further, as shown in the detailed view of Figure 12 The stent 510 is shown in an unexpanded (e.g., pre-deployed) configuration. In other words, Figure 12 The stent 510 shown in the detailed view of Figure 13 is shown in a deployed configuration. As shown, the stent 510 has a reduced outer diameter compared to the stent 510 in the deployed configuration (shown in the detailed view of Figure 12 Further, similar to the cases described above, in some cases, it can be desirable to design the stent 510 to include one or more preferential detachment regions 526. However, in the stent example shown in

[0111] For example, it can be appreciated that the preferential detachment regions 526 can include one or more strategically placed linear slits, channels, grooves, or stress concentrators that allow a region of the micro-patterned coat 522 to move in a direction away from an adjacent region of the micro-patterned coat 522 as the stent 510 expands from a collapsed pre-deployed configuration to an expanded deployed configuration. In other words, the preferential detachment regions 526 can define regions along the stent 510 where a first portion of the micro-patterned coat 522 is designed to detach from and space itself apart from a second portion of the micro-patterned coat 522, with the preferential detachment region 526 positioned between the detached first and second portions of the micro-patterned coat 522. It can be appreciated that Figure 12 The preferential detachment regions 526 shown in the detailed view are in a closed configuration, as the stent 510 has not yet expanded from a collapsed configuration to an expanded configuration.

[0112] Figure 12A A cross-sectional view taken along line 12A-12A is shown. Figure 12 Figure 12A A base coat 520 is shown surrounding each individual filament 518. Further, Figure 12A A base coat 520 is shown surrounding each individual filament 518. Further, Figure 12A A micro-patterned coating 522 is shown disposed on the base coat 520 (e.g., the micro-patterned coating 522 can be applied to the outer surface of the base coat 520). Further, the micro-patterned coating 522 can extend around the entire circumference of the stent 510 in the radially collapsed configuration.

[0113] Further, Figure 12A A detailed view of the micro-patterned coating 522 (including individual anti- migration elements 524) disposed along the base coat 520 is shown. Further, Figure 12A A preferential separation zone 526 is shown extending (e.g., radially inward from the outer surface of the micro-patterned coating 522) inside the wall 538 of the micro-patterned coating 522. As Figure 12A shown in FIG. 5B, the preferential separation zone 526 can extend only partially through the wall 538 of the coating (e.g., through the micro-patterned coating 522) to the outer surface of the base coat 520. However, it is also contemplated that in some examples, the preferential separation zone 526 can extend only through a portion of the thickness of the micro-patterned coating 522, or the preferential separation zone 526 can extend into or through the base coat 520.

[0114] Figure 13 A stent 510 is shown after having been expanded from the collapsed configuration (shown in FIG. 5A) to the expanded configuration. As described above, it is understood that as the stent 510 expands, the micro-patterned coating 522 can be placed under stress due to the expansion forces applied to the micro-patterned coating 522. Accordingly, similar to the method described above with respect to FIG. 5B, adjacent portions of the micro-patterned coating 522 can separate along the preferential separation zone 526, thereby forming longitudinal channels (grooves) 528 along the stent surface, with portions of the base coat 520 being exposed between the longitudinally separated micro-patterned coatings 522. Figure 12 Figures 9-11

[0115] As Figure 13 ​​​As shown in FIG. 26 (and as described above), the opening (e.g., separation) of one or more preferential separation zones 526 can reduce (e.g., mitigate) stress imparted by the stent deployment force, thereby preventing the micro-pattern coating 522 from tearing at undesired locations, but instead allowing predetermined portions of the micro-pattern coating 422 to separate from one another. For example, allowing the preferential separation zones 526 to separate adjacent portions of the micro-pattern coating 522 (e.g., to separate a portion of the micro-pattern coating 522 from another portion of the micro-pattern coating 522) can allow the stent 410 to more easily radially expand within a body lumen.

[0116] Figure 13A A cross-sectional view of FIG. 26 taken along line 13A-13A is shown. Figure 13 As described above, Figure 13A A stent 510 in an expanded configuration is shown. Figure 13A A base coating 520 surrounding each individual filament 518 is shown. Further, Figure 13A The base coating 520 can be shown spanning the cell openings of the stent 510. Further, Figure 13A A micro-pattern coating 522 disposed on the base coating 520 (e.g., the micro-pattern coating 522 can be applied to the outer surface of the base coating 520) is shown.

[0117] Further, Figure 13A A detailed view of FIG. 26 shows the micro-pattern coating 522 (including individual anti-migration elements 524) disposed along the base coating 520. Further, Figure 13A The micro-pattern coating 522 is shown having expanded along the preferential separation zones 526, whereby the preferential separation zones 526 form expansion "channels" 528, thereby exposing the base coating 520 between the separated portions (e.g., longitudinal bands) of the micro-pattern coating 522 that have moved apart or separated from one another. In other words, as the micro-pattern coating 522 expands, a portion of the micro-pattern coating 522 separates from an adjacent portion of the micro-pattern coating 522 to form a channel (groove) 528 along the preferential separation zone 526. As Figure 13A As shown in FIG. 26, the base coating 420 can extend across the channels 528 in the radially expanded configuration, thereby separating the channels 528 from the inner lumen of the stent 510. The base coating 520 can be composed of a material having greater elasticity than the material of the micro-pattern coating 522, such that as a first longitudinal band of the micro-pattern coating 522 separates from a second longitudinal band of the micro-pattern coating 522, the base coating 520 more easily stretches than the micro-pattern coating 522.

[0118] Although Figures 12-13AThe preferential separation zone 526 is depicted as a linear, longitudinal band extending along the entire length (or a portion of the entire length) of the stent 510, but it is understood that the preferential separation zone 526 can include other arrangements along the stent 510. For example, the separation zone 526 can extend in a helical arrangement along the stent 510.

[0119] As described above, it is understood that any of the micropatterned coatings described herein can be configured to prevent the stents described herein from longitudinally migrating or shifting relative to the inner surface of the body lumen when the stent is positioned adjacent to the target site (e.g., when placed in an adjacent position in the esophagus or intestine). In some cases, the micropatterned coating can include a variety of different textures based on the particular design and / or dimensions of the anti-migration elements. For example, the surface texture can include dots, spikes, barbs, ribs, bumps, ridges, protrusions, etc. that can be configured to protrude together, partially protrude into and / or through the wall of the body lumen, or engage the wall of the body lumen, thereby providing some degree of interaction (e.g., surface friction, mechanical interlocking, interfacing, engagement, etc.) between the micropatterned coating and the body lumen tissue (e.g., the esophagus or intestine). The engagement of the textured surface of the micropatterned coating with the body lumen tissue can initially prevent the stent from longitudinally migrating or shifting relative to the body lumen when implanted inside the body lumen. The micropatterned coating composition (including the surface texture) can form a frictional and / or adhesive bond with the body lumen tissue (e.g., the inner surface of the esophagus or intestine), which can prevent the stent from longitudinally migrating or moving relative to the body lumen. For example, in some cases, the surface texture can be designed to "grip" the inner surface of the body lumen.

[0120] The materials that can be used for the various components of any of the stents disclosed herein can include materials typically associated with medical devices. However, this is not intended to limit the materials to those described herein. Rather, the materials that can be used for the various components of any of the stents described herein can include metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, or other suitable materials. Some examples of suitable polymers can include poly: polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block copolymers (for example, PEbax®, available from Arkema), polyurethane (for example, Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC), polyether-ester based polymers (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based polymers (for example, butylene polymer), polyamide (for example, DURETHAN® available from Lancashire Engineering Plastics), copolymers of polyamide and polyurethane, block copolymers of polyisoprene and polybutadiene, combinations the same or therewith, or other suitable materials, and blends and composites thereof. Alternatively, it can be purchased from Elf Atochem. ), polyamide elastomers, polyamide / polyether block copolymers, polyether block amides (PEBA, for example, by trade name) Purchased), ethylene vinyl acetate copolymer (EVA), polysilicon, polyethylene (PE) High-density polyethylene, Low-density polyethylene, linear low-density polyethylene (e.g.) Polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene ether (PPO), poly(p-phenylene terephthalamide) (e.g., Polysulfone, nylon, nylon-12 (if available from EMS American Grilon) This includes perfluoropropyl vinyl ether (PFA), ethylene-vinyl alcohol copolymers, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) triblock copolymers (e.g., SIBS and / or SIBS 50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites thereof. In some embodiments, the sheath may be mixed with a liquid crystal polymer (LCP). For example, the mixture may contain up to about 6% LCP.

[0121] Some examples of suitable metals and metal alloys include: stainless steels such as 304V, 304L, and 316LV stainless steels; mild steels; nickel-peptide alloys such as linearly elastic and / or hyperelastic nickel-titanium alloys; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS:N06625, such as...). 625, UNS:N06022 UNS:N10276 other Alloys, etc.), nickel-copper alloys (e.g., UNS:N04400, such as...) 400, Nickel 400 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, etc.) (etc.), nickel-molybdenum alloys (e.g., UNS:N10665, etc.) alloy ), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as MP35-N® and CONART® and the like); platinum-rich stainless steel; titanium; combinations thereof; and the like; or any other suitable material.

[0122] In at least some embodiments, various components of the stents described herein can also be doped with, made from, or otherwise incorporate a radiopaque material. Radiopaque materials are understood to be materials capable of producing an image that can be detected by a medical imaging technique such as, for example, fluoroscopy or another imaging technique. Such relatively bright images assist a user in determining the location of various components of the stents described herein. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymer material loaded with a radiopaque filler, and the like. Additionally, other radiopaque marker bands and / or coils can be incorporated into the design of various components of the stents described herein to achieve the same result.

[0123] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility can be incorporated into various components of the stents described herein. For example, various components of the described stents can be made from a material that does not substantially distort the image and create substantial artifacts (e.g., gaps in the image). Certain ferromagnetic materials, for example, can be unsuitable because they can create artifacts in MRI images. Various components of the stents described herein can also be made from a material that the MRI machine can image. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as MP35-N® and CONART® and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35N® and CONART® and the like), nitinol, and the like, and other materials.

[0124] It should be understood that the present disclosure is only illustrative in many respects. Changes can be made in detail, particularly in matters of shape, size, and arrangement of steps without exceeding the scope of the present disclosure. To the extent that any exemplary embodiment is used in the description, it is intended to be illustrative only and not restrictive. Of course, the scope of the present disclosure is to be limited only by the language of the appended claims.

Claims

1. A medical stent for treating a body lumen, comprising: an expandable stent structure including a first end region, a second end region opposite the first end region, and an outer surface, wherein the expandable stent structure is configured to transition from a radially collapsed state to a radially expanded state; and a coating disposed along the outer surface of the expandable stent structure, wherein the coating includes a base coat and a micropatterned coat over the base coat, wherein at least a portion of the micropatterned coat includes a plurality of anti-migration elements extending outwardly from a wall of the micropatterned coat, wherein the micropatterned coat further includes a plurality of preferential separation zones extending only within the wall of the micropatterned coat, wherein each of the preferential separation zones are spaced apart from one another within the micropatterned coat; wherein each of the preferential separation zones is configured to define an aperture in the wall of the micropatterned coat when the expandable stent structure transitions from the radially collapsed state to the radially expanded state.

2. The medical stent of claim 1, wherein the preferential separation zones are configured to prevent the coating from separating from the outer surface of the expandable stent structure when the expandable stent structure transitions from the radially collapsed state to the radially expanded state.

3. The medical stent of claim 1, wherein the apertures extend completely through the wall of the micropatterned coat.

4. The medical stent of claim 1, wherein the apertures extend only partially through the wall of the micropatterned coat.

5. The medical stent of claim 1, wherein the apertures defined by the plurality of preferential separation zones are aligned along a longitudinal axis of the stent.

6. The medical stent of claim 5, wherein the alignment of the apertures of the preferential separation zones forms a perforated preferential separation zone.

7. The medical stent of claim 6, wherein the perforated preferential separation zone extends continuously along the longitudinal axis of the stent from the first end region to the second end region.

8. The medical stent of claim 6, wherein the perforated preferential separation zone extends linearly along the longitudinal axis of the stent.

9. The medical stent of claim 6, wherein the perforated preferential separation zone extends non-linearly along the longitudinal axis of the stent.

10. The medical stent of any one of claims 1-2, wherein the expandable stent structure includes a plurality of interwoven filaments, and wherein the plurality of filaments are arranged to define a plurality of cells therebetween, and wherein each of the preferential separation zones is positioned within one of the plurality of cells.

11. A medical stent for treating a body lumen, comprising: an expandable stent structure including a first end region, a second end region opposite the first end region, and an outer surface, wherein the expandable stent structure is configured to transition from a radially collapsed state to a radially expanded state; and a coating disposed along the outer surface of the expandable stent structure, wherein the coating includes a base coat and a micropatterned coat over the base coat, wherein at least a portion of the micropatterned coat includes a plurality of anti-migration elements extending outwardly from a wall of the micropatterned coat. wherein the micro-patterned coating further comprises a plurality of preferential separation zones extending only within the walls of the micro-patterned coating, and wherein each of the preferential separation zones are spaced apart from one another within the micro-patterned coating, and wherein each of the preferential separation zones are configured to define an aperture in the walls of the micro-patterned coating as the expandable stent structure transitions from a radially collapsed state to a radially expanded state, while the base coating extends across the aperture.

12. The medical stent of claim 11, wherein each of the preferential separation zones is positioned between a first region of the micro-patterned coating and a second region of the micro-patterned coating, and wherein each of the preferential separation zones are configured to allow the first region of the micro-patterned coating to separate from the second region of the micro-patterned coating along the respective preferential separation zone therebetween as the expandable stent structure transitions from a radially collapsed state to a radially expanded state.

13. The medical stent of any one of claims 11-12, wherein each of the plurality of preferential separation zones are configured to prevent the coating from separating from an outer surface of the expandable stent structure as the expandable stent structure transitions from a radially collapsed state to a radially expanded state.

14. The medical stent of any one of claims 11-12, wherein the aperture of each of the preferential separation zones extends completely through the walls of the micro-patterned coating.

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