Compressed stent with flexible covering

Abstract

A stent device includes a hollow tubular member having, in an initial configuration, an initial length; a stent frame surrounding a portion of the hollow tubular member when the hollow tubular member is in a compressed configuration, a length of the hollow tubular member in the compressed configuration being less than the initial length, the stent frame having a length less than the initial length; and an elastomeric coating applied to at least one of the hollow tubular member and the stent frame. First and second ends of the hollow tubular member are inverted over first and second ends of the stent frame to form an inverted portion so that the elastomeric coating extends between an outer surface of the stent frame and the inverted portion.

Description

COMPRESSED STENT WITH FLEXIBLE COVERINGInventors: Jamie Stephen HENDERSON and Kinh-Luan Due DAOPRIORITY CLAIM

[0001] The present disclosure claims priority to U.S. Provisional Patent Application Serial No. 63 / 512,898 filed July 10, 2023; the disclosure of which is incorporated herewith by reference.BACKGROUND OF THE DISCLOSUREField of the Disclosure

[0002] The present disclosure relates to a stent device for use within a body passageway or duct, and to methods of manufacturing a stent device.Description of Related Art

[0003] A common method for treating stenosed or aneuryzed vessels or other blocked passageways is to utilize an expandable prosthesis or stent device. The prosthesis or stent device is an expandable structure configured to be deployed in the vessel or passageway in an expanded state to maintain patency or continuity of the vessel or passageway.

[0004] In many surgical procedures, a stent device is configured to be delivered to a target site, expanded, and affixed in place. For example, in a fenestrated endovascular aneurysm repair (FEVAR) procedure, a number of stents may be placed within pre-formed openings or fenestrations in a main body implant or endoprosthesis to create a connection between the main body implant and target branch vessels or conduits. In vascular applications, covered stents can protrude into an aortic main body implant or endoprosthesis for a few millimeters. Once deployed and affixed in place, the stent(s) create an enclosed lumen space for passage of blood from the main body implant or endoprosthesis to the target vessels. The stent device(s) can also provide increased reinforcement of the vessel wall, in order to maintain the cleared lumen or passageway.

[0005] Conventional stents are often formed from a framework of interconnecting members or tines. Many stent designs are known and can include combinations of different types of framing structures, such as helical coils, meshes, lattices, or interconnected rings. In one common design, a stent can include a series of cylindrical rings aligned in a series along a central longitudinal axis. The rings can be fixedly secured to one another by a plurality of interconnecting members,such as longitudinally extending struts. Conventional stents can be covered or uncovered. The cover can be constructed from a biocompatible material, such as polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE).

[0006] Stent devices are typically flexible so as to conform to the shape of the vasculature in which they are placed. Further, flexibility eases insertion and deployment of the stent devices. ePTFE is often used for stent coverings to allow for a certain degree of flexibility while maintaining biocompatibility and other desirable material properties. Stent devices having ePTFE coverings generally exhibit good stretching characteristics in the radial direction, but relatively poor stretching characteristics in the axial direction. Thus, stent devices constructed in this manner tend to have a limited bend radius, and additional bending beyond this bend radius will result in plastic deformation and / or kinking of the stent devices.

[0007] Various designs and manufacturing methods have been employed to improve the flexibility of stent devices. One such design, commercially available under the trade name GORE® Viabahn VBX, is shown schematically in FIGS. 1-4. This stent device 100 includes a plurality of spaced-apart rings 120 joined by an ePTFE covering that spans gaps 140 between the rings 120. The rings 120 are not directly connected to one another, but rather are only held in their relative positions by the ePTFE covering. This arrangement allows for a relatively tight bend, as illustrated in FIG. 2, because the ePTFE covering can develop micro-folds in the gap 140' where the bend occurs. This allows the rings 120 adjacent to the gap 140' to come into close proximity to one another along the inside curve, resulting in a relatively tight bend radius.

[0008] A disadvantage of this design is that the rings 120 react poorly to shear stress, as illustrated in FIGS. 3 and 4. Because the rings 120 are not directly joined to one another, a shear stress applied in the vicinity of a particular gap 140" generally causes adjacent rings 120 to laterally shift relative to one another. As such, a first portion 102 of the stent device 100 may become laterally offset from a second portion 104 of the stent device 100 on an opposite side of the gap 140' '. As illustrated in FIG. 4, this may significantly reduce the cross-sectional area of a flow lumen 160 through the stent device 100. Another disadvantage of this design, also due to the lack of structural support in the gaps 140, is an increased susceptibility of the ePTFE covering to fatigue failures.SUMMARY OF THE DISCLOSURE

[0009] There is a need for new stent devices with improved flexibility while maintaining structural integrity and flow capacity.

[0010] Embodiments of the present disclosure are directed to a stent device, comprising: a hollow tubular member having, in an initial configuration, an initial length; a stent frame surrounding a portion of the hollow tubular member when the hollow tubular member is in a compressed configuration, a length of the hollow tubular member in the compressed configuration being less than the initial length, the stent frame having a length less than the initial length; and an elastomeric coating applied to at least one of the hollow tubular member and the stent frame, wherein first and second ends of the hollow tubular member inverted over first and second ends of the stent frame to form an inverted portion so that the elastomeric coating extends between an outer surface of the stent frame and the inverted portion.

[0011] In some embodiments, the hollow tubular member is made from at least one of polytetrafluoroethylene, expanded polytetrafluoroethylene, and fluorinated ethylene propylene.

[0012] In some embodiments, the hollow tubular member is inert.

[0013] In some embodiments, the stent device further comprising one or more compression layers applied to the inverted first and second ends of the hollow tubular member.

[0014] In some embodiments, the first and second ends of the hollow tubular member meet at a joint.

[0015] In some embodiments, the joint between the first and second ends of the hollow tubular member is located in proximity to one of the first and second ends of the stent frame.

[0016] In some embodiments, the joint between the first and second ends of the hollow tubular member is one of a butt joint or a lap joint.

[0017] In some embodiments, the elastomeric coating is present between the hollow tubular member and one of an entire surface of the stent frame or the outer surface of the stent frame.

[0018] In some embodiments, the hollow tubular member is axially compressed by approximately 5%, approximately 10%, approximately 20%, approximately 30%, approximately 40%, approximately 50%, approximately 60%, approximately 70%, or approximately 80% of a pre-compressed length based on a desired bending characteristic of the stent device.

[0019] In some embodiments, the elastomeric coating comprises multiple layers.

[0020] In some embodiments, the elastomeric coating is an adhesive.

[0021] In some embodiments, the elastomeric coating secures the hollow tubular member to the stent frame.

[0022] In some embodiments, the elastomeric coating is porous.

[0023] In some embodiments, the elastomeric coating is non-porous.

[0024] In some embodiments, the elastomeric coating distributes within pores between fibrils of the hollow tubular member.

[0025] In some embodiments, a thickness of the hollow tubular member is in a range of approximately 0.1 mil to 100 mils.

[0026] In some embodiments, the stent frame comprises a plurality of expandable rings connected by a plurality of struts.

[0027] Embodiments of the present disclosure are directed to a method of manufacturing a stent device, the method comprising axially stretching a hollow tubular member; axially compressing the hollow tubular member on a mandrel; applying an elastomeric coating over the compressed tubular member; positioning a stent frame over the elastomeric coating; inverting first and second ends of the hollow tubular member over first and second ends of the stent frame to form an inverted portion; and securing the inverted first and second ends of the hollow tubular member.

[0028] In some embodiments, the elastomeric coating is applied over the compressed tubular member prior to positioning the stent frame over the compressed tubular member.

[0029] In some embodiments, the elastomeric coating is applied over the stent frame and the compressed tubular member after the stent frame has been positioned on the compressed tubular member.

[0030] In some embodiments, the elastomeric coating is not applied between the stent frame and the compressed tubular member.

[0031] In some embodiments, the method further comprising at least partially sintering the hollow tubular member after stretching the hollow tubular member.

[0032] In some embodiments, securing the inverted first and second ends of the hollow tubular member comprises applying one or more layers of tape to the inverted first and second ends of the hollow tubular member.

[0033] In some embodiments, the method further comprising heating the stent device to a reflow temperature of the elastomeric coating.

[0034] In some embodiments, the hollow tubular member is axially compressed by approximately 5%, approximately 10%, approximately 20%, approximately 30%, approximately 40%, approximately 50%, approximately 60%, approximately 70%, or approximately 80% of a pre-compressed length on the mandrel based on a desired bending characteristic of the stent device.

[0035] In some embodiments, the method further comprising, prior to applying the elastomeric coating, rolling the compressed hollow tubular member to remove radial bulges from the compressed hollow tubular member.

[0036] In some embodiments, applying the elastomeric coating comprises at least one of submerging the compressed tubular member in the elastomeric coating; spraying the elastomeric coating onto the compressed tubular member; painting the elastomeric coating onto the compressed tubular member; and electrospinning the elastomeric coating onto the compressed tubular member.

[0037] In some embodiments, the elastomeric coating is applied in a plurality of layers.

[0038] In some embodiments, the hollow tubular member is made from at least one of polytetrafluoroethylene, expanded polytetrafluoroethylene, and fluorinated ethylene propylene.

[0039] In some embodiments, the first and second ends of the hollow tubular member meet at a joint.

[0040] In some embodiments, the joint between the first and second ends of the hollow tubular member is located in proximity to one of the first and second ends of the stent frame.

[0041] In some embodiments, the joint between the first and second ends of the hollow tubular member is one of a butt joint or a lap joint.

[0042] In some embodiments, the elastomeric coating is an adhesive.

[0043] In some embodiments, the elastomeric coating secures the hollow tubular member to the stent frame.

[0044] In some embodiments, the elastomeric coating is porous.

[0045] In some embodiments, the elastomeric coating is non-porous.

[0046] In some embodiments, the elastomeric coating distributes within pores between fibrils of the hollow tubular member.

[0047] In some embodiments, a thickness of the hollow tubular member is in a range of approximately 0.1 mil - 100 mils.

[0048] In some embodiments, the stent frame comprises a plurality of expandable rings connected by a plurality of struts.

[0049] In some embodiments, the hollow tubular member is axially compressed after the hollow tubular member has been axially stretched.

[0050] These and other features and characteristics of the devices and other embodiments described herein, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the disclosure. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG. 1 is a schematic side view of a stent device according to the prior art;

[0052] FIG. 2 is a schematic side view of the stent device of FIG. 1, bent into a curved orientation;

[0053] FIG. 3 is a schematic side view of the stent device of FIG. 1, under a shear load;

[0054] FIG. 4 is a schematic front view of the stent device of FIG. 1, under a shear load;

[0055] FIG. 5 is a cross-sectional view of a stent device according to an embodiment of the present disclosure;

[0056] FIG. 6 is a perspective view of a stent frame of the stent device of FIG. 5, in accordance with an embodiment of the present disclosure;

[0057] FIG. 7 is a sequence diagram of a method of manufacturing the stent device of FIG. 5, according to an embodiment of the present disclosure;

[0058] FIG. 8 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 7;

[0059] FIG. 9 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 7;

[0060] FIG. 10 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 7;

[0061] FIG. 11 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 7

[0062] FIG. 12 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 7

[0063] FIG. 13 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 7

[0064] FIG. 14 is a cross-sectional detail side view of Detail A of the stent device of FIG. 13;

[0065] FIG. 15 is a sequence diagram of a method of manufacturing a stent device, according to an embodiment of the present disclosure.

[0066] FIG. 16 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 15;

[0067] FIG. 17 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 15;

[0068] FIG. 18 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 15;

[0069] FIG. 19 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 15;

[0070] FIG. 20 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 15;

[0071] FIG. 21 is a side schematic view of a step in manufacturing a stent device, according to the method of FIG. 15;

[0072] FIG. 22 is a cross-sectional detail side view of Detail B of the stent device of FIG. 21;

[0073] FIG. 23 is a side view of a prior art stent device at a minimum radius;

[0074] FIG. 24 is a side view of a stent device, according to embodiments of the present disclosure, at a minimum radius;

[0075] FIG. 25 is a side detail view of the stent device of FIG. 24, in a bent position;

[0076] FIG. 26 is a side view of a stent frame of the stent device of FIG. 5, in accordance with an embodiment of the present disclosure;

[0077] FIG. 27 is a side view of a stent frame of the stent device of FIG. 5, in a bent position, in accordance with an embodiment of the present disclosure;

[0078] FIG. 28 is a side view of a stent frame of the stent device of FIG. 5, in accordance with an embodiment of the present disclosure; and

[0079] FIG. 29 is a side view of a stent frame of the stent device of FIG. 5, in accordance with an embodiment of the present disclosure.

[0080] Referring to the drawings in which like reference characters refer to like parts throughout the several views thereof, the present disclosure is generally directed to an extracorporeal circulation system and a fluid heating pump assembly for use in such a system.DETAILED DESCRIPTION

[0081] For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal”, and derivatives thereof shall relate to the disclosure as it is oriented in the drawing figures. Spatial or directional terms, such as “left”, “right”, “inner”, “outer”, “above”, “below”, and the like, are not to be considered as limiting as the disclosed embodiments can assume various alternative orientations.

[0082] As used herein, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

[0083] All numbers used in the specification and claims are to be understood as being modified in all instances by the term “about”. The terms “approximately”, “about”, and “substantially” mean a range of plus or minus ten percent of the stated value.

[0084] As used herein, the term “at least one of’ is synonymous with “one or more of’. For example, the phrase “at least one of A, B, and C” means any one of A, B, and C, or any combination of any two or more of A, B, and C. For example, “at least one of A, B, and C” includes one or more of A alone; or one or more of B alone; or one or more of C alone; or one or more of A and one or more of B; or one or more of A and one or more of C; or one or more of B and one or more of C; or one or more of all of A, B, and C. Similarly, as used herein, the term “at least two of’ is synonymous with “two or more of’. For example, the phrase “at least two of D, E, and F” means any combination of any two or more of D, E, and F. For example, “at least two of D, E, and F” includes one or more of D and one or more of E; or one or more of D and one or more of F; or one or more of E and one or more of F; or one or more of all of D, E, and F.

[0085] It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary examples of the disclosure. Hence, specific dimensions and other physical characteristics related to the examples disclosed herein are not to be considered as limiting.

[0086] The terms “first”, “second”, and the like are not intended to refer to any particular order or chronology, but refer to different conditions, properties, or elements.

[0087] The term “at least” is synonymous with “greater than or equal to”. The term “not greater than” is synonymous with “less than or equal to”.

[0088] It is to be understood that the disclosure may assume alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary aspects of the disclosure. Hence, specific dimensions and other physical characteristics related to the examples disclosed herein are not to be considered as limiting.

[0089] The present disclosure is generally directed to a stent device, such as stent device 50 shown in FIG. 5, configured to be implanted in a body passageway or duct of a patient. As illustrated in the cross-sectional view of FIG. 5, the stent device 50 is generally cylindrical in shape and defines a flow lumen 52 extending axially along the length of the stent device 50. However, as would be understood by those skilled in the art, flow lumen 52 and / or an exterior shape of the stent device 50 may be non-circular in cross-section (e.g., elliptical or any other curved shape designed to match an interior space of a body lumen within which it is to be deployed). Biological fluid (e.g. blood) is able to flow through the flow lumen 52 when the stent device 50 is implanted in a patient. The stent device 50 includes a stent frame 2 which defines the main structure of the stent device 50. Further details of an example of the stent frame 2 are shown in FIG. 6, which illustrates that the stent frame 2 is a substantially tubular structure (i.e., an elongated hollow member) extending between a first end 4 and a second end 6, and having a length L. In some embodiments, a tubular structure or body portion 12 of the stent frame 2 can be formed from a plurality of radially expandable rings 8 connected together by longitudinally extending members, tines, and / or struts. The body portion 12 extends along a longitudinal axis LI of the stent device 2.

[0090] With continued reference to FIG. 6, the rings 8 and members, tines, and / or struts of the stent frame 2 can be formed from suitable metal materials, such as stainless steel, cobalt chromium or nickel-titanium alloy (e.g., NITINOL). In other embodiments, the stent frame 2 can be formed from, for example, biocompatible polymers, absorbable polymers, and other biomaterials. If made from a shape memory material (e.g., NITINOL), the stent frame 2 can be biased to a deployed position or can be configured to assume a previously memorized shape (i.e., adopt the deployed position) after a shape-memory property of the material is activated (e.g., by being heated above a selected temperature, such as body temperature).

[0091] In some embodiments, the stent frame 2 including the pattern of elongate members and rings 8 disclosed herein can be cut from a continuous tube by automated cutting processes, such as laser cutting. In some embodiments, portions of the stent frame 2 can also be formed by connecting separate elongate members together to form the tubular structure. For example, elongated members can be connected together by ultrasonic welding, laser welding, or another suitable connecting process. Also, a plurality of tines or elongate members could be woven together to form portions of the stent frame 2. Additional details and embodiments of the stent frame 2 are illustrated and described in PCT International Application No. PCT / US2020 / 038981, filed June 22, 2020, the disclosure of which is hereby incorporated by reference in its entirety. Other embodiments of the stent frame 2 are shown in FIGS. 26-29.

[0092] Referring again to FIG. 5, the stent frame 2 is encased in one or more covering layers extending along the inner and / or outer surfaces of the stent frame 2. An innermost layer adjacent the flow lumen 52 is formed of a hollow tubular member 60, which is flexible both radially and axially so that the hollow tubular member 60 can contort with the stent frame 2 during deployment and use of the stent device 50. The hollow tubular member 60 may be made from, for example, polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), fluorinated ethylene propylene (FEP), or another suitable polymer or copolymer. The use of ePTFE, or another inert, biocompatible material may be preferred so as to not cause an adverse reaction with the patient’s blood or other biological materials. The thickness of the hollow tubular member 60 may be in a range of, for example, 0.1 mil - 100 mils. The hollow tubular member 60 may be axially compressed prior to being joined to the stent frame 2 and / or other components of the stent device 50. Thus, in a resting state of the stent device 50, the hollow tubular member 60 is under axial compression, but is prevented from returning to anuncompressed state by the stent frame 2. This axial compression of the hollow tubular member 60 improves the bending capabilities of the stent device 50, as will be described herein. In one embodiment, the hollow tubular member 60 may be configured so that, when axially compressed, accordion folds are created that are opened on the radially outer portions of the stent as it is bent. That is, the accordion folds provide additional length to the hollow tubular member 60 that are available to permit the stent device 50 to be bent without requiring that the material of the hollow tubular member 60 be stretched. That is, as the accordion folds unfold when the hollow tubular member 60 is bent, any resistance that would have been imparted to the bending of the stent device 50 by the need to stretch the hollow tubular member 60 is avoided and the overall bending capabilities of the stent device 50 are improved. To further improve the hollow tubular member 60, the accordion folds can be pushed back into the original cylindrical surface of the hollow tubular member 60 by rolling the generated accordion folds on the mandrel to push the fold slack back into the material of the hollow tubular member 60. This works to return the hollow tubular member 60 and the stent device 50 to the original diameter because, as would be understood by those skilled in the art, the ePFTE material is similar to a sponge in structure and is made up of nodes (clumps) of polymer held together by strings (fibrils) which extend primarily in the axial direction. The fibrils are forced to bend increasing the density of the structure as the microstructure is collapsed. As would be understood by those skilled in the art, this process is similar to pressing a wet sponge from the ends. After the structure arches out of plane, forming a macro- fold, it is pressed back down against the mandrel eliminating (or reducing the size of) voids in the material and increasing the density of the material while building in dimensional recovery slack to the original dimensions when you release the constraints. The ePTFE material is locked in the compressed state via an elastomer layer and the stent is built with this densified composite, which can now “stretch”.

[0093] As will be described in further detail below with regard to FIGS. 8-13, a first end 61 of the hollow tubular member 60 is rolled over the first end 4 of the stent frame 2, and a second end 63 of the hollow tubular member 60 is rolled over the second end 6 of the stent frame 2, forming an inverted portion 62 of the hollow tubular member 60. The inverted portion 62 forms an outer covering layer radially outside of the stent frame 2.

[0094] An elastomeric coating 70 is arranged between the hollow tubular member 60 and the stent frame 2 and an elastomeric coating 72 is arranged between the inverted portion 62 and thestent frame 2. The elastomeric coatings 70, 72 may be an adhesive that bonds the hollow tubular member 60 and the inverted portion 62 to the stent frame 2. The elastomeric coatings 70, 72 may be, for example, a thermoplastic polycarbonate polyurethane (PCU) (such as Bionate®), a polyester, copolymer, or combinations thereof. The elastomeric coatings 70, 72 may be conformal or non-conformal, and may be applied continuously over an interior surface of the hollow tubular member 60 and the inverted portion 62 and / or applied in non-continuous sections over the hollow tubular member 60 and the inverted portion 62. The thickness of the elastomeric coating 70 may vary at different locations. In some embodiments, as shown in FIGS. 5 and 14, the elastomeric coatings 70, 72 are arranged between the stent frame 2 and the hollow tubular member 60 on the inner surface of the stent frame 2, as well as between the stent frame 2 and the inverted portion 62 of the hollow tubular member 60 on the outer surface of the stent frame 2. The layered arrangement of FIG. 5 is achieved by applying the elastomeric coating 70 to the hollow tubular member 60, then applying the stent frame 2, and then rolling the inverted portion 62 over the stent frame 2, as described below in connection with method 700 of FIG. 7. In other embodiments, as shown for example in FIG. 22, the elastomeric coating 70 is present only between the stent frame 2 and the inverted portion 62 of the hollow tubular member 60 on the outer surface of the stent frame 2. The layered arrangement of FIG. 22 is achieved by positioning the stent frame 2 directly on the hollow tubular member, then applying the elastomeric coating 70 to the stent frame 2, and then rolling the inverted portion 62 over the stent frame 2, as described below in connection with method 800 of FIG. 15.

[0095] Referring now to FIG. 7, a sequence diagram of a method 700 of assembling the stent device 50 is shown according to an embodiment of the present disclosure. FIGS. 8-13 illustrate certain corresponding steps in the sequence shown in FIG. 7. In step 701 of the method 700, the hollow tubular member 60, at this stage in a pre-formed state, is stretched or expanded along its longitudinal axis, either manually or using automated equipment. In some embodiments, the hollow tubular member 60 may be stretched by a factor in a range of 4: 1 to 6: 1, for example, although stretching to a greater or lesser extent may also be utilized, in certain embodiments approximately 10: 1 or approximately 15: 1. After stretching, the stretched hollow tubular member 60 may be partially sintered, fully sintered, or not sintered at all.

[0096] In step 702 of the method 700, the hollow tubular member 60 is positioned on a mandrel 80. As shown in FIG. 8, the mandrel 80 may extend axially through the hollow tubularmember 60, and each end of the mandrel 80 may extend beyond corresponding first and second ends 61, 63 of the hollow tubular member 60. Stretching the hollow tubular member 60 at step 701 may have the effect of making the hollow tubular member 60 tacky, which can inhibit the ability of the hollow tubular member 60 to move on the mandrel 80. To prevent the hollow tubular member 60 from sticking to the mandrel 80, a lubricant (such as an isoparaffinic solvent or an alcohol) may be applied to the mandrel 80 before positioning the hollow tubular member 60 on the mandrel 80. In other embodiments, the lubricant may be applied to the hollow tubular member 60 and allowed to absorb into the pores of the hollow tubular member 60 before positioning the hollow tubular member 60 on the mandrel 80.

[0097] Referring again to FIG. 7, at step 704 of the method 700, the hollow tubular member 60 is axially compressed along its longitudinal axis on the mandrel 80, which shortens a length of the hollow tubular member 60. As such, the first and second ends 61, 63 of the hollow tubular member 60 are brought closer together by compression of the hollow tubular member 60, as shown in FIG. 9. The lubricant applied to the mandrel 80 and / or the hollow tubular member 60 at step 702 may reduce the friction between the hollow tubular member 60 and the mandrel 80 to reduce the force necessary to compress the hollow tubular member 60 and facilitating substantially uniform compression along the length of the hollow tubular member 60. In some embodiments, the hollow tubular member 60 may be compressed by approximately 50%, such that a compressed length Lc of the hollow tubular member 60 is approximately half of the length to which the hollow tubular member 60 was stretched at step 702. In other embodiments, the hollow tubular member 60 may be compressed more than 50%, such as about 60%, about 70%, or about 80%. In other embodiments, the hollow tubular member 60 can be compressed less than 50%, such as about 5%, about 10%, about 20%, about 30%, or about 40%. The extent of compression may be selected according to the desired final properties of the fully formed device, and based on the extent of stretching performed at step 701. Particularly, greater stretching at step 701 may allow for greater compression at step 702. To ensure that the resulting stent device 50 (see FIG. 5) exhibits desired bending characteristics, the hollow tubular member 60 should be compressed uniformly along its length. As previously noted, a lubricant may be used to facilitate uniform compression. Compression of the hollow tubular member 60 can be achieved in a variety of ways, either manually or with appropriate tooling.

[0098] As a result of the compression, the hollow tubular member 60 develops internal stresses that may induce the hollow tubular member 60 to radially deflect, creating radial bulges. To compensate and ensure the hollow tubular member 60 remains cylindrical and tight to the mandrel 80, the hollow tubular member 60 may be rolled against the mandrel 80 with appropriate tooling. The resulting compressed hollow tubular member 60 has a microstructure of bent and / or compressed fibrils due to the compression performed at step 704.

[0099] Referring again to FIG. 7, at step 706 of the method 700, the elastomeric coating 70 is applied over the hollow tubular member 60. Although shown subsequent to step 704 in FIG. 7, step 706 could be performed either prior to step 704, i.e., prior to compressing the hollow tubular member 60, or after step 704, i.e., while the hollow tubular member 60 is in the axially compressed state from step 704. The elastomeric coating 70 may be applied in a variety of ways, such as submerging the hollow tubular member 60 in the elastomeric coating 70, spraying the elastomeric coating 70 onto the hollow tubular member 60, painting the elastomeric coating 70 onto the hollow tubular member 60, electrospinning the elastomeric coating 70 onto the hollow tubular member 60, or combinations thereof. As shown in FIG. 10, the first end 61 of the hollow tubular member 60 may extend beyond a corresponding first end 71 of the elastomeric coating 70, such that the first end 61 is uncovered by the elastomeric coating 70. The second end 63 of the hollow tubular member 60 may be covered by a corresponding second end 73 of the elastomeric coating 70. The elastomeric coating 70, acting as a bonding agent, holds the hollow tubular member 60 in the compressed state.

[0100] Depending on the materials used and method of application, the elastomeric coating 70 may take any number of forms, such as porous, non-porous, nanofiber-based, conformal, non- conformal, continuous or intermittent layers, discontinuous layers, and combinations thereof. In some embodiments, the elastomeric coating 70 may be applied in multiple layers and / or using multiple processes to produce desired combinations of properties. In some embodiments, the elastomeric coating 70 is applied as droplets.

[0101] In some embodiments, the assembly of the hollow tubular member 60 and the elastomeric coating 70 is removed from the mandrel 80 after step 706, as application of the elastomeric coating 70 is sufficient to hold the hollow tubular member 60 in the compressed state. In other embodiments, as shown in the accompanying drawings, the remainder of the method 700 is performed with the assembly still on the mandrel 80.

[0102] Referring again to FIG. 7, at step 708 of the method 700, the stent frame 2 is positioned over the elastomeric coating 70, such that the stent frame 2 surrounds a portion of the hollow tubular member 60 and the elastomeric coating 70. As shown in FIG. 11, the stent frame 2 may be positioned such that the first end 4 is offset from the first end 71 of the elastomeric coating 70, leaving the first end 61 of the hollow tubular member 60 and the first end 71 of the elastomeric coating 70 uncovered. The length L (see FIG. 6) of the stent frame 2 is less than the length Lc (see FIG. 9) of the axially compressed hollow tubular member 60 and the length of the elastomeric coating 70. In some embodiments, the length Lc of the axially compressed hollow tubular member 60 may be at least twice the length L of the stent frame 2 so that after inverting the hollow tubular member 60 at subsequent steps 710 and 712, the stent frame 2 is completely covered by after inverting the hollow tubular member 60.

[0103] Referring again to FIG. 7, at step 710 of the method 700, the first end 61 of the hollow tubular member 60 is inverted over the first end 4 of the stent frame 2. As shown in FIG. 12, the first end 61 of the hollow tubular member 60 is inverted (e.g., rolled or folded) over the first end 4 of the stent frame 2 such that a portion of the hollow tubular member 60 that previously laid against the mandrel 80 now forms the inverted portion 62 which becomes an external surface of the partially formed stent device. The length of the inverted portion 62 is substantially equal to the length of the hollow tubular member 60 that extends beyond the stent frame 4, as shown in FIG. 11, minus a rolled section 65 of the hollow tubular member 60 that wraps over the first end 4 of the stent frame 2. The first end 71 of the elastomeric coating 70 may also be inverted over the stent frame 2 as a consequence of the first end 61 of the hollow tubular member 60 being inverted. Inverting of the first end 61 of the hollow tubular member 60 may be achieved using a cuffing tool or other suitable tooling.

[0104] Referring again to FIG. 7, at step 712 of the method 700, the second end 63 of the hollow tubular member 60 is inverted over the second end 6 of the stent frame 2, much in the same manner as the first end 61 in step 710. In some embodiments, the first and second ends 61, 63, may meet at a joint 67 on an outer surface of the stent device 50. The joint 67 may be a butt joint, lap joint, or the like. The joint 67 may be inherently more rigid than the remainder of the stent device 50. As such, the joint 67 may be positioned in proximity to one of the ends 4, 6 of the stent frame 2 to optimize flexibility in the midsection of the body portion 12 (see FIG. 6) of the stent frame 2. In other embodiments, the first and second ends 61, 63 of the hollow tubularmember 60 are spaced apart from one another on the outer surface of the stent device 50. The joint can be placed anywhere along the length of the stent device 50. In one embodiment, the joint is in the middle of the stent device 50 longitudinally while in an alternative embodiment, the joint may be shifted toward either end of the stent device 50. As certain embodiments are configured as a flexible device and the joint creates a slightly stiffer region, placing it in the middle may restrict some of the bending capability / perceived flexibility. Thus, for certain applications, placement of the joint near one or both ends of the stent device 50 may be desirable. In addition, by placing the joint near the end, it can create added padding at a location where the stent device 50 may be configured to contact a fenestration port, increasing the wear resistance of the stent device 50.

[0105] Referring again to FIG. 7, at step 714 of the method 700, the inverted first and second ends 61, 63 of the hollow tubular member 60 are secured to the underlying structure. In some embodiments, one or more compression layers such as compression tape 68, e.g., ePTFE compression tape, are temporarily applied to (e.g., wrapped around) the joint 67 to hold the first and second ends 61, 63 in place (see FIG. 14, wherein the compression tape 68 is shown in dashed lines to indicate that the compression tape 68 is later removed). In embodiments where the first and second ends 61, 63 of the hollow tubular member 60 are spaced apart, the compression tape 68 may be applied to each of the first and second ends 61, 63, individually. In some embodiments, the stent device 50 is heated to at least a reflow or processing temperature of the elastomeric coating 70 on the hollow tubular member 60 to adhere the entire structure of the stent device 50 together and to improve structural properties of the stent device 50. The reflow process causes the elastomeric coating 70 to flow and distribute within the pores between the fibrils of the hollow tubular member 60 where, for example, the elastomeric coating 70 may distribute only on the outer surface layers of the hollow tubular member 60. This greatly improves the adhesion of the layers of the hollow tubular member 60 while relieving the stress on the elastomeric coating 70 and resetting the neutral position of the polymer(s). The processing temperature must remain less than a sintering temperature of the hollow tubular member 60 (e.g. less than 327°C or 621° F for ePTFE) to minimize risk that slack in the fibrils of the hollow tubular member 60 will be compromised. Additionally, the processing temperature must remain less than a sintering temperature of the hollow tubular member 60 to permit the compression tape 68 to be subsequently removed.

[0106] Following the reflow process, the compression tape 68 is removed. In some embodiments, heat shrink tubing 69 (see FIG. 14) is applied and shrunk over the joint 67. The heat shrink tubing 69 may extend partially or fully along the length of the stent device 50.

[0107] FIG. 14 is a cross-sectional detail view of the stent device 50 at step 712 of the method 700. As previously described in connection with steps 710 and 712 of the method 700, the first and second ends 61, 63 of the hollow tubular member 60 are inverted over the stent frame 2 to form the inverted portion 62. The rolled section 65 is the portion of the hollow tubular member 60 that wraps over the first end 4 of the stent frame 2, defining a transition between the inverted portion 62 and the portion of the hollow tubular member 60 that remains on the inside of the stent frame 2. A similar rolled section is present over the second end 6 of the stent frame 2, which is not shown in FIG. 14. The first end 71 of the elastomeric coating 70 may be rolled over the first end 4 of the stent frame 2 as a consequence of the first end 61 of the hollow tubular member 60 being inverted. As a result of the manufacturing process of method 700, the elastomeric coating 70 is present between the hollow tubular member 60 and an inner surface of the stent frame 2, and the elastomeric coating 70 is present between the inverted portion 62 and an outer surface of the stent frame 2.

[0108] Referring now to FIG. 15, a sequence diagram of another method 800 of assembling a stent device 51 is shown according to an embodiment of the present disclosure. FIGS. 16-21 illustrate corresponding steps in the sequence shown in FIG. 15. The method 800 is similar to the method 700, with the exception that the elastomeric coating 70 is applied to the hollow tubular member 60 over the stent frame 2, such that the inner surface of the stent frame 2 is in direct contact with the hollow tubular member 60. This results in a stent device 51 (as shown in FIG. 22) having a different arrangement of layers than the stent device 50 of FIG. 14.

[0109] Referring again to FIG. 15, steps 801, 802 and 804 of the method 800 are identical to steps 701, 702, and 704, respectively, of the method 700 of FIG. 7. In step 801 of the method 800, the hollow tubular member 60, at this stage in a pre-formed state, is stretched or expanded along its longitudinal axis, either manually or using automated equipment. In some embodiments, the hollow tubular member 60 may be stretched by a factor in a range of 4: 1 to 6: 1, for example, although stretching to a greater or lesser extent may also be utilized, in certain embodiments approximately 10: 1 or approximately 15: 1. After stretching, the stretched hollow tubular member 60 may be partially sintered, fully sintered, or not sintered at all.

[0110] In step 802 of the method 800, the hollow tubular member 60 is positioned on a mandrel 80. As shown in FIG. 16, the mandrel 80 may extend axially through the hollow tubular member 60, and each end of the mandrel 80 may extend beyond corresponding first and second ends 61, 63 of the hollow tubular member 60. Stretching the hollow tubular member 60 at step 801 may have the effect of making the hollow tubular member 60 tacky, which can inhibit the ability of the hollow tubular member 60 to move on the mandrel 80. To prevent the hollow tubular member 60 from sticking to the mandrel 80, a lubricant (such as an isoparaffinic solvent or an alcohol) may be applied to the mandrel 80 before positioning the hollow tubular member 60 on the mandrel 80. In other embodiments, the lubricant may be applied to the hollow tubular member 60 and allowed to absorb into the pores of the hollow tubular member 60 before positioning the hollow tubular member 60 on the mandrel 80.

[0111] Referring again to FIG. 15, at step 804 of the method 800, the hollow tubular member 60 is axially compressed along its longitudinal axis on the mandrel 80, which shortens a length of the hollow tubular member 60. As such, the first and second ends 61, 63 of the hollow tubular member 60 are brought closer together by compression of the hollow tubular member 60, as shown in FIG. 17. The lubricant applied to the mandrel 80 and / or the hollow tubular member 60 at step 802 may reduce the friction between the hollow tubular member 60 and the mandrel 80, thereby reducing the force necessary to compress the hollow tubular member 60 and facilitating substantially uniform compression along the length of the hollow tubular member 60. In some embodiments, the hollow tubular member 60 may be compressed by approximately 50%, such that a compressed length Lc of the hollow tubular member 60 is approximately half of the length to which hollow tubular member 60 was stretched at step 802. In other embodiments, the hollow tubular member 60 may be compressed more than 50% such as about 60%, about 70% or about 80%. In other embodiments, the hollow tubular member may be compressed less than 50% such as about 5%, about 10%, about 20%, about 30% or about 40%. The extent of compression may be selected according to the desired final properties of the fully formed device, and based on the extent of stretching performed at step 801. Particularly, greater stretching at step 801 may allow for greater compression at step 802. To ensure that the resulting stent device 51 (see FIG. 22) exhibits desired bending characteristics, the hollow tubular member 60 should be compressed uniformly along its length. As previously noted, a lubricant may be used to facilitate uniformcompression. Compression of the hollow tubular member 60 can be achieved in a variety of ways, either manually or with appropriate tooling.

[0112] As a result of the compression, the hollow tubular member 60 develops internal stresses that may induce the hollow tubular member 60 to radially deflect, creating radial bulges. To compensate and ensure the hollow tubular member 60 remains cylindrical and tight to the mandrel 80, the hollow tubular member 60 may be rolled against the mandrel 80 with appropriate tooling. The resulting compressed hollow tubular member 60 has a microstructure of bent and / or compressed fibrils due to the compression performed at step 804.

[0113] Referring again to FIG. 15, at step 806 of the method 800, the stent frame 2 is positioned over the compressed hollow tubular member 60, such that the stent frame 2 surrounds a portion of the hollow tubular member 60. As shown in FIG. 18, the stent frame 2 may be positioned such that the first end 4 is offset from the first end 61 of the hollow tubular member 60, leaving the first end 61 of the hollow tubular member 60 uncovered. The length L (see FIG. 6) of the stent frame 2 is less than the length Lc (see FIG. 17) of the axially compressed hollow tubular member 60. In particular, the length Lc of the axially compressed hollow tubular member 60 may be at least twice the length L of the stent frame 2 so that after the hollow tubular member 60 is inverted in subsequent steps 810 and 812, the stent frame 2 is completely covered by the hollow tubular member 60.

[0114] Referring again to FIG. 15, at step 808 of the method 800, the elastomeric coating 70 is applied over the stent frame 2 and the hollow tubular member 60, while the hollow tubular member 60 is still in the axially compressed state from step 804. The elastomeric coating 70 may be applied in a variety of ways, such as submerging the compressed tubular member 60 in the elastomeric coating 70, spraying the elastomeric coating 70 onto the compressed tubular member 60, painting the elastomeric coating 70 onto the compressed tubular member 60, electrospinning the elastomeric coating 70 onto the compressed tubular member 60, or combinations thereof. As shown in FIG. 19, the stent frame 2 is entirely covered by elastomeric coating 70 (which is shown transparently in FIGS. 19 and 20 so that the underlying stent frame 2 can be seen). The first end 61 of the hollow tubular member 60 may extend beyond the corresponding first end 71 of the elastomeric coating 70, such that the first end 61 is uncovered by the elastomeric coating 70. The second end 63 of the hollow tubular member 60 may be covered by a corresponding second end 73 of the elastomeric coating 70. The elastomericcoating 70, acting as a bonding agent, holds the hollow tubular member 60 to the stent frame 2 in the compressed state.

[0115] Depending on the materials used and method of application, the elastomeric coating 70 may take any number of forms, such as porous, non-porous, nanofiber-based, conformal, non- conformal, continuous or intermittent layers, discontinuous layers, and combinations thereof. In some embodiments, the elastomeric coating 70 may be applied in multiple layers and / or using multiple processes to produce desired combinations of properties. In some embodiments, the elastomeric coating 70 is applied as droplets.

[0116] Referring again to FIG. 15, at step 810 of the method 800, the first end 61 of the hollow tubular member 60 is inverted over the first end 4 of the stent frame 2. As shown in FIG. 20, the first end 61 of the hollow tubular member 60 is inverted (e.g., rolled or folded) over the first end 4 of the stent frame 2 such that a portion of the hollow tubular member 60 that previously laid against the mandrel 80 now forms the inverted portion 62 which becomes an external surface of the partially formed stent device. The length of the inverted portion 62 is substantially equal to the length of the hollow tubular member 60 that extends beyond the stent frame 4, as shown in FIG. 19, minus the rolled section 65 (see FIG. 22) of the hollow tubular member 60 that wraps over the first end 4 of the stent frame 2. The first end 71 of the elastomeric coating 70 may also be inverted over itself and / or the stent frame 2 as a consequence of the first end 61 of the hollow tubular member 60 being inverted. Inverting of the first end 61 of the hollow tubular member 60 may be achieved using a cuffing tool or other suitable tooling.

[0117] Referring again to FIG. 15, at step 812 of the method 800, the second end 63 of the hollow tubular member 60 is inverted over the second end 6 of the stent frame 2, much in the same manner as the first end 61 in step 810. In some embodiments, the first and second ends 61, 63, may meet at ajoint 67 on an outer surface of the stent device 51. The joint 67 may be a butt joint, lap joint, or the like. The joint 67 may be inherently more rigid than the remainder of the stent device 50. As such, the joint 67 may be positioned in proximity to one of the ends 4, 6 of the stent frame 2 to optimize flexibility in the midsection of the body portion 12 (see FIG. 6) of the stent frame 2. In other embodiments, the first and second ends 61, 63 of the hollow tubular member 60 are spaced apart from one another on the outer surface of the stent device 51.

[0118] Referring again to FIG. 15, at step 814 of the method 800, the inverted first and second ends 61, 63 of the hollow tubular member 60 are secured to the underlying structure. Insome embodiments, one or more layers of compression tape 68, e.g., ePTFE compression tape, are temporarily applied to (e.g., wrapped around) the joint 67 to hold the first and second ends 61, 63 in place (see FIG. 22, wherein the compression tape 68 is shown in dashed lines to indicate that the compression tape 68 is later removed). In embodiments where the first and second ends 61, 63 of the hollow tubular member 60 are spaced apart, the compression tape 68 may be applied to each of the first and second ends 61, 63, individually. In some embodiments, the stent device 51 is heated to at least a reflow or processing temperature of the elastomeric coating 70 on the hollow tubular member 60 to adhere the entire structure of the stent device 51 together and to improve structural properties of the stent device 51. The reflow process causes the elastomeric coating 70 to flow and distribute within the pores in between the fibrils of the hollow tubular member 60. This greatly improves the adhesion of the layers of the hollow tubular member 60 while relieving the stress in the elastomeric coating 70 and resetting the neutral position of the polymer(s). The processing temperature must remain at least less than a sintering temperature of the hollow tubular member 60 (e.g., less than 342°C or 648° F for unsintered ePTFE) to minimize the risk that slack in the fibrils of the hollow tubular member 60 will be compromised. Additionally, the processing temperature must remain less than a sintering temperature of the hollow tubular member 60 to permit the compression tape 68 to be subsequently removed.

[0119] Following the reflow process, the compression tape 68 is removed. In some embodiments, heat shrink tubing 69 (see FIG. 22) is applied and shrunk over the joint 67. The heat shrink tubing 69 may extend partially or fully along the length of the stent device 51.

[0120] FIG. 22 is a cross-sectional detail view of the stent device 51 at step 812 of the method 800. As previously described in connection with steps 810 and 812 of the method 800, the first and second ends 61, 63 of the hollow tubular member 60 are inverted over the stent frame 2 to form the inverted portion 62. The rolled section 65 is the portion of the hollow tubular member 60 that wraps over the first end 4 of the stent frame 2, defining a transition between the inverted portion 62 and the portion of the hollow tubular member 60 that remains on the inside of the stent frame 2. A similar rolled section is present over the second end 6 of the stent frame 2, which is not shown in FIG. 22. The first end 71 of the elastomeric coating 70 may be inverted over itself and / or the stent frame 2 as a consequence of the first end 61 of the hollow tubular member 60 being inverted. As a result of the manufacturing process of method 800, theelastomeric coating 70 is present between the inverted portion 62 and an outer surface of the stent frame 2, but, in contrast to the method 700, the elastomeric coating 70 is absent between the hollow tubular member 60 and an inner surface of the stent frame 2.

[0121] The exemplary embodiments describe a process of assembling the stent devices 50, 51 in which the first and second ends 61, 63 of the hollow tubular member 60 are inverted over the stent frame 2. However, this manner of placing the hollow tubular member 60 on the stent frame 2 is only illustrative and the exemplary embodiments may utilize other manners. In a further exemplary embodiment, the exemplary embodiments may utilize a process in which multiple distinct compressed layers are placed on the stent frame 2. For example, an inner layer may be placed within the stent frame 2 and an outer layer may be placed outside the stent frame 2. One or both of these layers may stretch over the ends of the stent frame 2. Alternatively, a further layer may be placed on the ends of the stent frame 2. These layers may be applied to the stent frame 2 and / or connected to one another using any of the above described mechanisms.

[0122] Referring now to FIGS. 23 and 24, a comparison of minimum bending radii (e.g., the tightest bend that can be achieved without plastic deformation) of the stent devices 50, 51 and a prior art stent device 90 is illustrated. The prior art stent device 90, shown in FIG. 23, includes a stent frame encased in a covering layer (e.g., ePTFE) layer. However, unlike the stent devices 50, 51 of the present disclosure, the covering layer of the prior art stent device 90 is not compressed prior to being mated with the stent frame. FIG. 23 shows a prior art stent device 90 having essentially similar dimensions to the stent device 50, 51 of the present disclosure, which is shown in FIG. 24. The stent device 50, 51 of the present disclosure, exhibits enhanced bending characteristics relative to the prior art stent device 90. In particular, the minimum bending radius R2 of the stent devices 50, 51 of the present disclosure is less than the minimum bending radius R1 of the prior art stent device 90. As a result, the stent device 50, 51 of the present disclosure may be easier to deploy within the patient’s vasculature and may be less susceptible to plastic deformation (e.g., kinking) that could limit flow through the stent device 50, 51.

[0123] With continued reference to FIG. 24, the improved bending characteristics of the stent device 50, 51 compared to the prior art is due to the hollow tubular member 60 being precompressed (as shown in FIGS. 9 and 17) prior to being mated to the stent frame 2. As shown in FIG. 24, bending of the stent device 50, 51 causes a relative elongation of an outer surface OS ofthe stent device 50, 51 relative to an inner surface IS. Thus, to achieve a bend, the outer surface OS must stretch, the inner surface IS must compress, or a combination of both must occur. As over-compression of the inner surface IS can cause the stent device 50, 51 to kink (particularly when the covering is made of ePTFE and like polymers), it is advantageous that much of the bending result from stretching of the outer surface OS rather than compression of the inner surface IS.

[0124] Referring now to FIG. 25, stretching of the outer surface OS may be analyzed by measuring an arc distance S between arbitrary points Pl, P2 on the outer surface OS. Empirical analysis has shown that, in certain embodiments of the stent device 50, 51 of the present disclosure, the arc distance S increases by approximately 23.00% at a bend of approximately 90°, and the arc distance S increases by approximately 30.16% at a bend of approximately 180°, relative to the unbent state of the stent device 50, 51. In contrast, the prior art stent device 90 of FIG. 23 exhibits less stretching of the outer surface OS under the same degree of bending. To compensate for the reduced capacity for stretching of the outer surface OS, the inner surface IS of the prior art stent device 90 must compress more to achieve a comparable bend radius to the stent devices 50, 51 of the present disclosure. Thus, for any given bending angle, the inner surface IS of the prior art stent device 90 is under more compressive load than the inner surface IS of the stent devices 50, 51 of the present disclosure. As a result, the prior art stent device 90 will experience compression failure of the inner surface IS (resulting in kinking of the prior art stent device 90) at a greater bend angle whereas the stent devices 50, 51 of the present disclosure will not experience the compression failure at the same greater bend angle.

[0125] Additionally, the structure of the stent frame 2 of the stent device 50, 51 of the present disclosure may provide significant hoop strength (e.g., resistance to crushing / buckling) which prevents the inner surface IS from kinking under compressive load.

[0126] Accordingly, the minimum bend radius Rl, corresponding to a bend radius at which compression failure of the inner surface IS occurs, of the prior art stent device 90 is greater than the minimum bend radius R2 of the stent device 50, 51 of the present disclosure.

[0127] Referring now to FIGS. 26-29, other embodiments of the stent frame 2a-2c are illustrated. Referring first to FIGS. 26 and 27, embodiments of a stent frame 2a may include a plurality of elongated connectors 16’ arranged at predetermined intervals between expandable rings 18’. Selectively positioning the elongated connectors 16’ between adjacent ring 18’, thestent frame 2a can be configured to hinge or bend easily in at least one direction. Further, hinge points of the stent frame 2a, 2b, 2c can be selectively positioned for different ring elements creating a multi -directional hinging stent frame 2a that provides enhanced stent flexibility in multiple directions or in any desired direction while maintaining radial stiffness and axial stiffness. For example, FIG. 26 shows the stent frame 2a in a linear configuration and FIG. 27 shows the stent frame 2a hinging about a hinging axis as defined by a positioning and orientation of the elongated connectors 16’ about the rings 18’. Further details of the stent frame 2a of FIGS. 26 and 27 are described in U.S. Provisional Patent Application Serial No. 63 / 512,877 titled “Multi-Directional Hinging Stent” filed on July 10, 2023 (Docket No. ATRI.l 141PR01), the disclosures of which are hereby incorporated by reference in its entirety. FIG. 28 illustrates a stent frame 2b that may include a plurality of elongated connectors 16” arranged at predetermined intervals between expandable rings 18”. In a substantially similar manner as the stent frame 2a, the elongated connectors 16” of the stent frame 2b may be selectively positioned for hinge points to be created that enhance stent flexibility while maintaining radial stiffness and axial stiffness. In the stent frame 2a of FIGS. 26 and 27, the elongated connectors 16’ may be substantially linear whereas, in the stent frame 2b of FIG. 28, the elongated connectors 16” may exhibit a funnel shape. FIG. 28 shows the stent frame 2b in an as-cut view to show the shape of the elongated connectors 16”. Further details of the stent frame 2b of FIG. 28 are described in U.S. Provisional Patent Application Serial No. 63 / 512,887 titled “Multi-Directional Hinging Stent with One Or More Funnel Shaped Connectors” filed on July 10, 2023 (Docket No. ATRI.1089PR01), the disclosures of which are hereby incorporated by reference in its entirety.

[0128] Referring now to FIG. 29, embodiments of the stent frame 2c may include a first outwardly flaring portion 13’” and a second outwardly flaring portion 14’”, each including a radially expandable ring 18’”, connected by a plurality of struts 16”’. Each of the first and second outwardly flaring portions 13”’, 14’” further include flaring connectors 19’” connected to the ring 18’” and configured to cause portions or segments of the ring 18’” to flare radially outwardly relative to other portions of the ring 18’” as the ring 18’” expands. Further details of the stent frame 2d of FIG. 29 are described in International Application No.PCT / US2020 / 057107, filed on October 23, 2020, the disclosure of which is hereby incorporated by reference in its entirety.

[0129] While various examples of the present disclosure were provided in the foregoing description, those skilled in the art may make modifications and alterations to these examples without departing from the scope and spirit of the disclosure. For example, it is to be understood that features of various embodiments described herein may be adapted to other embodiments described herein. Accordingly, the foregoing description is intended to be illustrative rather than restrictive. The disclosure described hereinabove is defined by the appended claims, and all changes to the disclosure that fall within the meaning and the range of equivalency of the claims are to be embraced within their scope.

Claims

CLAIMS:

1. A stent device, comprising: a hollow tubular member having, in an initial configuration, an initial length; a stent frame surrounding a portion of the hollow tubular member when the hollow tubular member is in a compressed configuration, a length of the hollow tubular member in the compressed configuration being less than the initial length, the stent frame having a length less than the initial length; and an elastomeric coating applied to at least one of the hollow tubular member and the stent frame, wherein first and second ends of the hollow tubular member inverted over first and second ends of the stent frame to form an inverted portion so that the elastomeric coating extends between an outer surface of the stent frame and the inverted portion.

2. The stent device of claim 1, wherein the hollow tubular member is made from at least one of polytetrafluoroethylene, expanded polytetrafluoroethylene, and fluorinated ethylene propylene.

3. The stent device of claim 1, wherein the hollow tubular member is inert.

4. The stent device of claim 1, further comprising one or more compression layers applied to the inverted first and second ends of the hollow tubular member.

5. The stent device of claim 1, wherein the first and second ends of the hollow tubular member meet at a joint.

6. The stent device of claim 5, wherein the joint between the first and second ends of the hollow tubular member is located in proximity to one of the first and second ends of the stent frame.

7. The stent device of claim 5, wherein the joint between the first and second ends of thehollow tubular member is one of a butt joint or a lap joint.

8. The stent device of claim 1, wherein the elastomeric coating is present between the hollow tubular member and one of an entire surface of the stent frame or the outer surface of the stent frame.

9. The stent device of claim 1, wherein the hollow tubular member is axially compressed by approximately 5%, approximately 10%, approximately 20%, approximately 30%, approximately 40%, approximately 50%, approximately 60%, approximately 70%, or approximately 80% of a pre-compressed length based on a desired bending characteristic of the stent device.

10. The stent device of claim 1, wherein the elastomeric coating comprises multiple layers.

11. The stent device of claim 1, wherein the elastomeric coating is an adhesive.

12. The stent device of claim 1, wherein the elastomeric coating secures the hollow tubular member to the stent frame.

13. The stent device of claim 1, wherein the elastomeric coating is porous.

14. The stent device of claim 1, wherein the elastomeric coating is non-porous.

15. The stent device of claim 1, wherein the elastomeric coating distributes within pores between fibrils of the hollow tubular member.

16. The stent device of claim 1, wherein a thickness of the hollow tubular member is in a range of approximately 0.1 mil to 100 mils.

17. The stent device of claim 1, wherein the stent frame comprises a plurality of expandable rings connected by a plurality of struts.

18. A method of manufacturing a stent device, the method comprising: axially stretching a hollow tubular member; axially compressing the hollow tubular member on a mandrel; applying an elastomeric coating over the compressed tubular member; positioning a stent frame over the elastomeric coating; inverting first and second ends of the hollow tubular member over first and second ends of the stent frame to form an inverted portion; and securing the inverted first and second ends of the hollow tubular member.

19. The method of claim 18, wherein the elastomeric coating is applied over the compressed tubular member prior to positioning the stent frame over the compressed tubular member.

20. The method of claim 18, wherein the elastomeric coating is applied over the stent frame and the compressed tubular member after the stent frame has been positioned on the compressed tubular member.

21. The method of claim 20, wherein the elastomeric coating is not applied between the stent frame and the compressed tubular member.

22. The method of claim 18, further comprising at least partially sintering the hollow tubular member after stretching the hollow tubular member.

23. The method of claim 18, wherein securing the inverted first and second ends of the hollow tubular member comprises applying one or more layers of tape to the inverted first and second ends of the hollow tubular member.

24. The method of claim 18, further comprising heating the stent device to a reflow temperature of the elastomeric coating.

25. The method of claim 18, wherein the hollow tubular member is axially compressed by approximately 5%, approximately 10%, approximately 20%, approximately 30%, approximately40%, approximately 50%, approximately 60%, approximately 70%, or approximately 80% of a pre-compressed length on the mandrel based on a desired bending characteristic of the stent device.

26. The method of claim 18, further comprising, prior to applying the elastomeric coating, rolling the compressed hollow tubular member to remove radial bulges from the compressed hollow tubular member.

27. The method of claim 18, wherein applying the elastomeric coating comprises at least one of: submerging the compressed tubular member in the elastomeric coating; spraying the elastomeric coating onto the compressed tubular member; painting the elastomeric coating onto the compressed tubular member; and electrospinning the elastomeric coating onto the compressed tubular member.

28. The method of claim 18, wherein the elastomeric coating is applied in a plurality of layers.

29. The method of claim 18, wherein the hollow tubular member is made from at least one of polytetrafluoroethylene, expanded polytetrafluoroethylene, and fluorinated ethylene propylene.

30. The method of claim 18, wherein the first and second ends of the hollow tubular member meet at a joint.

31. The method of claim 30, wherein the joint between the first and second ends of the hollow tubular member is located in proximity to one of the first and second ends of the stent frame.

32. The method of claim 30, wherein the joint between the first and second ends of the hollow tubular member is one of a butt joint or a lap joint.

33. The method of claim 18, wherein the elastomeric coating is an adhesive.

34. The method of claim 18, wherein the elastomeric coating secures the hollow tubular member to the stent frame.

35. The method of claim 18, wherein the elastomeric coating is porous.

36. The method of claim 18, wherein the elastomeric coating is non-porous.

37. The method of claim 18, wherein the elastomeric coating distributes within pores between fibrils of the hollow tubular member.

38. The method of claim 18, wherein a thickness of the hollow tubular member is in a range of approximately 0.1 mil - 100 mils.

39. The method of claim 18, wherein the stent frame comprises a plurality of expandable rings connected by a plurality of struts.

40. The method of claim 18, wherein the hollow tubular member is axially compressed after the hollow tubular member has been axially stretched.

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