Inflatable balloon and cover

Abstract

To provide implantable medical devices comprising covers, such as a balloon cover.SOLUTION: Devices comprise a layer 312 of a porous polymeric material, such as ePTFE, surrounded by composite layers 316 of a porous polymeric material having an imbibed elastomer, such as polyurethane. A cover can be used to assist in deployment of an expandable implant, such as a stent-graft, within the body of a patient.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure generally relates to medical balloons, and more particularly to pleated medical balloons and covers.

Background Art

[0002] Inflatable balloons and covers are frequently used in interventional medical procedures. For example, inflatable balloons may be used for angioplasty procedures such as coronary or peripheral angioplasty, and may also be used to assist in the implantation of expandable medical devices such as stents or stent-grafts. The inflatable balloon may be coaxially surrounded by a cover to improve the performance of the inflatable balloon or to provide certain functional or clinical advantages.

[0003] Generally, the inflatable balloon and cover are delivered to the treatment site of the patient through the vasculature or other body lumen or cavity by a balloon catheter. Further, the balloon catheter may include an expandable implant such as a stent or stent-graft, and it coaxially surrounds the inflatable balloon and cover. By inflating the inflatable balloon and applying sufficient force to expand the expandable implant against the tissue at the desired treatment site of the patient, the expandable implant can be deployed at the treatment site of the patient. For example, inflatable balloons and covers having improved inflation characteristics such as lower inflation pressures or more uniform deployment of expandable implants can be beneficial.

Summary of the Invention

[0004] In various embodiments, a medical balloon according to the present disclosure includes an outer cover of a continuously wrapped sheet, the sheet having an innermost porous polymer layer and a composite layer including a porous polymer that has absorbed an elastomeric component.

[0005] In other embodiments, the outer cover of the medical balloon according to the present disclosure comprises at least one pleat aligned along at least a portion of the longitudinal axis.

[0006] In yet another embodiment, the catheter assembly according to the present disclosure includes a catheter tube, a balloon coupled to the catheter tube and having at least one pleat when in a flattened shape, and an outer cover coaxially surrounding the balloon having at least one pleat, wherein the inner surface of the outer cover substantially coincides with the outer surface of the balloon.

[0007] In various embodiments, a method for forming a cover according to the present disclosure includes the steps of: absorbing an elastomer into a portion of a first surface of a porous polymer sheet to form an absorbent section and a non-absorbent section; winding the porous polymer sheet onto a mandrel such that the non-absorbent section is in contact with a second surface of the porous polymer sheet to form a first polymer layer; and winding the porous polymer sheet onto the mandrel such that the absorbent section is in contact with the second surface to form at least one composite layer comprising a porous polymer that has absorbed an elastomer component.

[0008] Furthermore, a method for forming a cover according to the present disclosure may include the steps of: heat-treating a first polymer layer and at least one composite layer comprising a porous polymer that has absorbed an elastomer component to form a cover; cooling the cover; removing the cover from a mandrel; coaxially surrounding a balloon with the cover; inflating the balloon and cover to operating pressure; and pleating the balloon and cover while deflating them.

[0009] The accompanying drawings are provided to further illustrate the present disclosure and are incorporated herein as part of this specification and are used in conjunction with the following description to illustrate embodiments of the present disclosure and to illustrate the principles of the present disclosure. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows a side view of the medical device described herein.

[0011] [Figure 2] Figure 2 shows a perspective view of the medical device described herein.

[0012] [Figure 3] Figure 3 shows a cross-sectional view of the medical device according to this disclosure.

[0013] [Figure 4] Figure 4 shows the materials used to manufacture the medical device according to this disclosure.

[0014] [Figure 5] Figure 5 shows a side view of the medical device described herein. Detailed explanation

[0015] It will be readily apparent to those skilled in the art that various aspects of this disclosure can be realized by several methods and systems configured to perform the intended functions. In other words, other methods and systems can be incorporated herein to perform the intended functions. It should also be noted that not all accompanying drawings referred to herein are drawn to the same scale and may be exaggerated to illustrate various aspects of this disclosure, and in this regard, the drawings should not be interpreted restrictively.

[0016] As used herein, “medical device” includes, for example, stents, grafts, stent-grafts, filters, valves, occluders, markers, mapping devices, drug delivery devices, prostheses, pumps, heart valves, heart valve frames or prestents, sensors, closure devices, anti-embolic devices, anchors, cardiac or nerve stimulation leads, gastrointestinal sleeves, and other intraluminal devices or implantable prostheses inserted into the lumen or cavity of a patient’s vascular system or other body.

[0017] The medical devices, inflatable components, balloons, support structures, coatings, and covers described herein may be biocompatible. As used herein, “biocompatible” means conforming to and meeting the purpose and requirements of a medical device used in long-term or short-term implants or non-implantable applications. Long-term implants are generally defined as devices implanted for more than approximately 30 days. Short-term implants are generally defined as devices implanted for approximately 30 days or less.

[0018] Throughout the specification and in the claims, the term “proximal” refers to a location or portion of the implant that is closer to the physician or clinician and / or the insertion site through which the implant and delivery system pass when inserted. Similarly, the term “proximal direction” refers to a direction toward such a location.

[0019] Furthermore, throughout the specification and in the claims, the term “distal” refers to a location or portion of the implant that, when inserted, is far from the physician or clinician and / or from the insertion site through which the implant and delivery system pass. Similarly, the term “distal direction” refers to a direction away from such a location.

[0020] With regard to the terms proximal and distal, this disclosure should not be interpreted narrowly with respect to these terms. Rather, the devices and methods described herein may be modified and / or adapted according to the patient's biological structure.

[0021] As used herein, “deployment” refers to the operation or placement of a device at a treatment site, such as the positioning of a stent at a treatment site and subsequent radial expansion with a medical balloon, or the positioning of a sleeve-covered self-expanding stent at a treatment site and removal of the sleeve to expand the stent to the same level as the surrounding tissue. The deployment process may also occur in stages, for example, a first stage including the release of the sleeve to a shape suitable for constraining the expandable device to an intermediate shape, a second stage including the complete removal of the sleeve from the device, and / or a third stage including further expansion of the device with a medical balloon.

[0022] Various embodiments of the present disclosure include catheter assemblies configured to deliver a balloon or a balloon with a cover to a treatment site in a patient's blood vessel. According to embodiments of the present disclosure, the catheter assembly comprises an inflatable balloon and a cover. The inflatable balloon and cover can assist in the deployment of an expandable implant, such as a stent-graft, by applying pressure to the inner surface of the expandable implant. The pressure allows the implant to fully expand and fit into the vessel wall. Advantages of the catheter assemblies according to the present disclosure may include improved deployment characteristics of the balloon, cover, and / or expandable implant, such as improved operational characteristics of the balloon and / or cover, including reduced inflation pressure, and improved uniformity of inflation of the balloon or balloon with cover.

[0023] Referring first to Figure 1, an example of a catheter assembly 100 according to the present disclosure is shown. The catheter assembly 100 comprises a catheter tube 102 having a continuous lumen 104. A cover 106 coaxially surrounding a balloon 108 is coupled to the catheter tube 102 and the continuous lumen 104 at or near the distal end of the catheter tube 102. Attachment of the cover 106 to the catheter tube 102 can be achieved in various ways, including, for example, by bonding the proximal and distal ends of the cover 106 to the catheter tube using an adhesive such as a cyanoacrylate adhesive.

[0024] In various embodiments, balloon 108 includes a generally tubular balloon that can be inflated within a patient's blood vessel by pressurization. For example, a biocompatible fluid, such as water or physiological saline, is introduced into catheter tube 102, passes through continuous lumen 104, through an inflation port (not shown) within catheter tube 102 located inside balloon 108, and pressurizes balloon 108. When the pressure on balloon 108 is increased, the diameter of balloon 108 also increases.

[0025] Balloon 108 can include, for example, a non-compliant, generally inelastic balloon. In such embodiments, balloon 108 can include materials such as nylon, polyethylene, polyethylene terephthalate (PET), polycaprolactam, polyester, polyether, polyamide, polyurethane, polyimide, ABS copolymer, polyester / polyether block copolymer, ionomer resin, liquid crystal polymer, and rigid rod polymer that are configured to expand balloon 108 to a selected diameter upon sufficient pressurization and maintain a set diameter or a diameter close thereto until the burst pressure is reached even under further pressurization.

[0026] In various embodiments, balloon 108 can include a compliant, relatively elastic balloon. In such embodiments, balloon 108 can include materials such as elastomeric organic silicone polymers such as polyurethane, latex, and polysiloxane that are configured to continuously increase the diameter of balloon 108 as the pressure on balloon 108 increases. When the inflation limit is reached, balloon 108 may burst.

[0027] In yet another embodiment, the balloon 108 may include a semi-driven balloon. In such an embodiment, the balloon 108 behaves in a manner that combines driven and semi-driven attributes. As described in relation to the driven and non-driven embodiments, including combinations of driven and non-driven behavior, the materials or shapes that allow the balloon 108 to inflate in a predictable manner within the patient's body are within the scope of this disclosure.

[0028] With respect to Figure 2, in various embodiments, the balloon 108 may include a plurality of pleats 210. The pleats 210 may include, for example, folds or bends in the material of the balloon 108 that generally extend along at least a portion of the long axis of the balloon 108. In such embodiments, the balloon 108 may have a substantially tubular shape having one or more pleats 210.

[0029] In various embodiments, the balloon 108 may be coaxially surrounded by a cover 106. The cover 106 may have an inner surface that substantially matches the outer surface of the balloon 108, such that both the balloon 108 and the cover 106 have substantially matching outer shapes, including when the balloon 108 is deflated. However, in other embodiments, the cover 106 may have a different outer shape or form from the balloon 108.

[0030] In various embodiments, the cover 106 may include a plurality of pleats 210. Similar to the balloon 108, the pleats 210 may include folds or bends in the material of the cover 106, for example, extending generally along at least a portion of its long axis. In such embodiments, the cover 106 may have a substantially tubular shape with two or more pleats 210. In various embodiments, the cover 106 includes the same number of pleats 210 as the balloon 108. In various embodiments, along at least a portion or the entirety of the operating length of the balloon cover 106, the inner surface of the balloon cover 106 interacts with the outer surface of the balloon 108 in both pleated, flattened and unpleated, inflated forms.

[0031] The pleats 210 may be formed simultaneously by the cover 106 and the balloon 108. For example, the balloon 108 may be coaxially surrounded by the cover 106, and then the pleats 210 may be formed by both the balloon 108 and the cover 106.

[0032] In other embodiments, the pleats 210 may be formed on the cover 106 after the pleats 210 have been formed on the balloon 108. For example, the balloon 108 before pleating may be coaxially surrounded by the cover 106. In such embodiments, both the cover 106 and the balloon 108 before pleating can be inflated together to the operating pressure, and then the cover 106 and balloon 108 can be subjected to a mechanical pleating process in which, for example, the same number and shape of pleats as on the balloon 108 before pleating can be formed on the cover 106. While the pleats 210 are being formed on the cover 106, both the cover 106 and balloon 108 can also be deflated and compressed for delivery into the patient's body. As described in specific embodiments, all modes of pleating on the cover 106 are within the scope of this disclosure.

[0033] In yet another embodiment, the balloon 108 may include a plurality of pleats 210, and the cover 106 may not include any pleats 210 at all. In such an embodiment, the pleats 210 may be formed in the balloon 108, and subsequently the cover 106 may be arranged coaxially around the outer surface of the balloon 108. While specific examples have been described in relation to cases where both the balloon 108 and the cover 106 have pleats, or where only the balloon 108 has pleats, all shapes in which the balloon 108 and / or the cover 106 have a plurality of pleats are within the scope of this disclosure.

[0034] For example, cover 106 may contain polymers such as stretched polytetrafluoroethylene (ePTFE), modified (e.g., high-density) ePTFE, and stretched copolymers of PTFE, such as stretched fluoropolymers. In various embodiments, the stretched fluoropolymer may contain nodes and fibril microstructures. In various embodiments, the stretched fluoropolymer may consist of a high proportion of fibrils, i.e., a nonwoven fabric of fused fibrils. While described in relation to specific polymers, all materials or shapes that allow cover 106 to inflate in a predictable manner within the patient's body are within the scope of this disclosure.

[0035] In various embodiments, the cover 106 may comprise a multilayer film of polymer material. For example, the cover 106 may comprise a polymer material that is continuously wound onto a substrate or mandrel to form a substantially tubular member. In various embodiments, the cover 106 may be configured with circumferential, helical, or axial orientation of the polymer material. As used herein, “orientation” refers to a directional orientation of the properties of the polymer material, such as the orientation of the strength of the material and / or the microstructure of the material. In such embodiments, the polymer material may generally be wound perpendicular to the long axis of the mandrel or substrate, i.e., wound circumferentially. In other embodiments, the material may be wound perpendicular to the long axis of the mandrel or substrate. The material may be wound at an angle greater than 0 degrees and less than 90 degrees, that is, it may be wound in a spiral. In yet another embodiment, the polymer material may be wound generally parallel to the long axis of the mandrel or substrate, that is, it may be wound axially (or along the long axis).

[0036] In various embodiments, the cover 106 may have an inner surface that is a low-friction surface to facilitate the unfolding of the pleats of the cover 106 and / or the balloon 108 during inflation. For example, the inner surface of the cover 106 may contain ePTFE or be essentially made of ePTFE. Alternatively, a lubricant may be applied to the inner surface of the cover 106. Furthermore, in various embodiments, the cover 106 may have an outer surface that is a low-friction surface to facilitate the deployment of the medical device. For example, the outer surface of the cover 106 may contain ePTFE or be essentially made of ePTFE. Alternatively, a lubricant, such as a dry lubricious coating, may be applied to the outer surface of the cover 106.

[0037] In other embodiments, the cover 106 may have an inner surface that is a high-friction surface or an adhesive coating to facilitate the adhesion of the cover 106 to the balloon 108. For example, at least a portion of the cover 106 may include a coating such as fluorinated ethylene propylene that can help the inner surface of the cover 106 adhere to the outer surface of the balloon 108.

[0038] The cover 106 may contain, for example, a non-porous polymer. In such embodiments, the non-porous polymer can reduce and / or prevent leakage of the inflation fluid into the patient's body through the cover 106. Furthermore, the non-porous polymer can reduce and / or prevent blood from entering the cover 106 and / or balloon 108.

[0039] In various embodiments, cover 106 may also include a coating that provides therapeutic benefit to the patient. For example, cover 106 may include a coating that is heparin, sirolimus, paclitaxel, everolimus, ABT-578, mycophenolic acid, tacrolimus, estradiol, oxygen free radical scavenger, biolimus A9, anti-CD34 antibody, PDGH receptor blocker, MMP-1 receptor blocker, VEGF, G-CSF, HMG-CoA reductase inhibitor, iNOS and eNOS stimulants, ACE inhibitors, ARBs, doxycycline, and thalidomide. Any coating that can assist in the deployment of cover 106 and / or balloon 108 is within the scope of this disclosure.

[0040] The cover 106 may include, for example, a porous polymer material whose surface at least partially absorbs the elastomer. In various embodiments, the cover 106 may include a multilayer film of the elastomer-absorbing porous polymer. With respect to Figure 3, the cover 106 may include an innermost porous polymer layer 312 and at least one composite layer 316. In such embodiments, the composite layer 316 may include a porous polymer that has absorbed the elastomer 314. As illustrated in Figure 3, the multiple composite layers 316 may coaxially surround the innermost porous polymer layer 312. In various embodiments, the outermost layer of the cover 106 is the composite layer 316, and the outer surface of the cover 106 is substantially free of elastomer.

[0041] In various embodiments, the innermost porous polymer layer 312 may include a porous polymer layer having a thickness greater than that of at least one composite layer 316. For example, the innermost porous polymer layer 312 may include a layer that is at least twice as thick as one or more composite layers 316.

[0042] The innermost porous polymer layer 312 and / or composite layer 316 may include, for example, stretched polytetrafluoroethylene (ePTFE) or ultra-high molecular weight polyethylene. However, any porous polymer that is biocompatible and capable of absorbing a suitable elastomer is within the scope of this disclosure.

[0043] Elastomer 314 may include, for example, polyurethane (e.g., Tecothane®). However, all suitable elastomers are within the scope of this disclosure.

[0044] In various embodiments, the cover 106 may include a porous polymer layer and an elastomer layer formed by a process of absorption into a section and winding. For example, as illustrated in Figure 4, the sheet 422 having a first surface 424 and a second surface 430 may include a porous polymer material such as ePTFE.

[0045] In various embodiments, the sheet 422 may include an absorbent section 428 and a non-absorbent section 426. The absorbent section 428 may be formed, for example, by absorbing an elastomer, such as elastomer 314, into the sheet 422 in a portion of the first surface 424 of the sheet 422. The absorbent section 428 may be formed, for example, by a "butter coating" or slot die coating. In such embodiments, the elastomer material, such as elastomer 314, is absorbed into the surface of the sheet 422 throughout the absorbent section 428. In various embodiments, the elastomer absorbed into the first surface 424 may include polyurethane.

[0046] After preparing the absorption compartment 428, the sheet 422 may be formed into a substantially tubular member. In various embodiments, the sheet 422 may be wound around a mandrel 418 to form a substantially tubular member. For example, the porous polymer of the sheet 422 may contain an anisotropic polymer such that the sheet 422 has a higher matrix tensile strength in a particular direction. In such a configuration, the sheet 422 may be oriented relative to the mandrel 418 so that the sheet 422 is wound around the mandrel 418 in a winding direction 420 that is substantially perpendicular to the direction of the higher matrix tensile strength; that is, the higher matrix tensile strength is oriented axially. In other configurations, the sheet 422 may be oriented relative to the mandrel 418 and wound around the mandrel 418 so that the higher matrix tensile strength of the sheet 422 is helically oriented. In other configurations, the sheet 422 is oriented relative to the mandrel 418 and wound around the mandrel 418 so that it is oriented circumferentially, thereby increasing the matrix tensile strength of the sheet 422.

[0047] In other embodiments, the sheet 422 may contain an isotropic porous polymer. In such embodiments, the sheet 422 is wound around the mandrel 418 in a direction 420 that is not related to the direction of higher or lower matrix tensile strength.

[0048] In various embodiments, and with reference to Figures 3 and 4, the area of ​​the non-absorbent compartment 426 may correspond to a desired thickness of the innermost porous polymer layer 312. For example, the non-absorbent compartment 426 may have a depth d1, which may correspond to a direction 420. In various embodiments, the depth d1 may correspond to a desired thickness of the innermost porous polymer layer 312. For example, the mandrel 418 may have a certain circumference, where the depth d1 is equal to or greater than that circumference. In such a configuration, the sheet 422 may be wound around the mandrel 418 such that the non-absorbent compartment 426 of the first surface 424 contacts the second surface 430 to form an innermost porous polymer layer 312 having the thickness of the sheet 422. In other embodiments, the depth d1 is equal to or greater than twice the circumference of the mandrel 418 such that the innermost porous polymer layer 312 has a thickness of at least twice that of the non-absorbent compartment 426 of the sheet 422.

[0049] In various embodiments, the absorption compartment 428 of the surface 424 has a depth d2. In such embodiments, the depth d2 can correspond to a desired number of composite layers 316. For example, the depth d2 may be equal to or longer than the outer circumference of the mandrel 418, which may result in only one composite layer 316. In other embodiments, the depth d2 may be equal to or longer than twice the outer circumference of the mandrel 418, which may result in two or more composite layers 316.

[0050] In various embodiments, the balloon 108 and the cover 106 may be heat-bonded to each other. In such embodiments, at least a portion of the balloon 108 and the cover 106 may be bonded to each other. Such thermal bonding may be temporary and may facilitate the uniform deployment of the balloon 108 and the cover 106. All forms of bonding, including non-thermal techniques, provided for the uniform deployment of the balloon 108 and the cover 106 are within the scope of this disclosure.

[0051] With respect to Figure 5, in various embodiments, the catheter assembly 100 further includes an expandable implant 540. In such embodiments, the expandable implant 540 is positioned coaxially around the balloon 108 and / or cover 106 so that the balloon 108 and / or cover 106 can cause the expandable implant 540 to expand.

[0052] The expandable implant 540 may include, for example, a balloon expandable implant. In such a configuration, inflation of the balloon 108 and / or cover 106 is required to cause expansion of the expandable implant 540. Sufficient inflation of the balloon 108 and / or cover 106 can cause deployment of the expandable implant 540, for example, by causing expansion in all or part of the expandable implant 540 against the vascular wall 532. In various embodiments, after deployment of the expandable implant 540, the balloon 108 and cover 106 may be deflated, and the catheter assembly 100 may be removed from the patient's body.

[0053] In other embodiments, the expandable implant 540 may comprise a self-expanding implant. When released from its restraints, such a device expands from a radially collapsed shape to a radially expanded shape. In such a shape, the expandable implant 540 can be partially deployed within the patient's blood vessel by removing any restraints on the expandable implant and expanding the implant to a radially expanded shape, including a partially deployed shape. In various embodiments, the balloon 108 and / or cover 106 may be inflated to cause the partially deployed expandable implant 540 to a fully deployed shape. For example, the expandable implant 540 may be expanded by the balloon 108 and / or cover 106 so that all or part of the expandable implant 540 is in contact with the blood vessel wall 532.

[0054] In various embodiments, the expandable implant 540 may comprise at least one stent member and, optionally, a graft member. In various embodiments, at least one stent member comprises a biocompatible material. For example, the stent member may be formed from a metal, polymer or natural material, and may include conventional medical-grade materials such as nylon, polyacrylamide, polycarbonate, polyethylene, polyformaldehyde, polymethyl methacrylate, polypropylene, polytetrafluoroethylene, polytrifluorochloroethylene, polyvinyl chloride, polyurethane, elastomer organosilicon polymer; malleable and unmalletable metals including stainless steel, cobalt-chromium alloy and nitinol, and bio-derived materials such as bovine arteries / veins, pericardium and collagen. The stent member may also include bioabsorbable materials such as poly(amino acids), poly(anhydrous), poly(caprolactone), poly(lactic acid / glycolic acid) polymers, poly(hydroxybutyrate) and poly(orthoester), as well as biodegradable metals and alloys. Any material that is biocompatible and provides appropriate support to the patient's blood vessels is in accordance with this disclosure.

[0055] Stent components can include various shapes, such as rings, connecting rings, cut tubes, wound wires (or ribbons), or flat molded sheets wound into the shape of a tube. However, any shape of a stent component that may be implanted in a patient's blood vessel and provides support to the patient's blood vessel is conforming to this disclosure.

[0056] In various embodiments, the stent member may comprise one or more anchors. For example, one or more anchors may be located at or near one end or both ends of the stent member. In such configurations, the anchors may be embedded in or attached to the patient's blood vessel to maintain the expandable implant 540 at a desired position within the blood vessel. In various embodiments, a balloon 108 and / or cover 106 may be inflated to embed the anchors into the blood vessel wall 532, and the anchors may help maintain the expandable implant 540 at the desired position. The use of any number and shape of anchors is within the scope of this disclosure.

[0057] In various embodiments, the expandable implant 540 comprises a graft member. The graft member may include, for example, a biocompatible material such as ePTFE that provides a lumen for blood flow within a blood vessel. Any graft member that provides a sufficient lumen for blood flow within a blood vessel is conforming to this disclosure. [Examples]

[0058] Example 1 An ePTFE membrane was obtained in accordance with the teachings of US5,476,589 issued to Bacino (the entirety of the aforementioned patent document is incorporated herein by reference for all purposes). The membrane was cut into strips approximately 90 mm wide and wound mechanically in a direction parallel to the total length of the roll. Polyurethane (Tecothane® 1074 (Lubrizol Corporation, Wickliffe, Ohio, USA)) was absorbed into a portion of the membrane, approximately 65% ​​(approximately 60 mm) of the roll width, in accordance with the general teachings of U.S. Patent Application Publication No. 2008 / 0125710 to Hobson et al. (incorporated herein by reference).

[0059] The absorbed polyurethane only spread partway through the underlying ePTFE membrane, creating a coating on its surface. The absorbed portion was approximately 10 microns thick. The remaining 35% (approximately 30 mm) of the roll width was left unabsorbed ("tail").

[0060] The non-absorbent portion of ePTFE had the following properties: thickness = 0.00635 mm, density = 0.42 g / cc, matrix tensile strength in the strongest (mechanical) direction = 18049 psi, matrix tensile strength in the transverse direction (perpendicular to the strongest direction) = 458 psi.

[0061] A sheet of locally absorbent ePTFE was cut from a roll; the sheet was 150 mm long. A stainless steel mandrel with a diameter of 2.2 mm and a length of 220 mm was selected. The tail of the sheet was positioned at the top of the non-absorbent portion. The sheet was continuously wound around the mandrel by orienting the strongest direction of the sheet parallel to the axis of the mandrel. The non-absorbent tail was wound around the mandrel first, and then the winding continued until the remaining portion of the sheet was wound onto the mandrel, with the polyurethane coated side facing the mandrel. In total, the sheet was wound around the mandrel approximately 13 and 1 / 3 times.

[0062] The wrapped mandrel was heat-treated at 230°C for approximately 3 minutes, and then cooled to room temperature. The ends of the wrapped sheet were then aligned to be slightly longer than the balloon to which the cover would be attached. The selected balloon was a nylon balloon attached to a catheter (model number 08GK-762C, manufactured by Bavaria Medizin Technologie (BMT), D-82234 Oberpfaffenhofen, Germany).

[0063] The wrapped sheet, which is currently in the shape of a tubular component, was removed from the mandrel and positioned coaxially around the balloon. The cover and balloon were compressed in a stamping machine to remove air from between the two elements. A thin layer of Dymax® adhesive (model number 204-CTH, Dymax Corp., Torrington, CT, USA) was applied to each end of the cover and adjacent catheter shaft, and the adhesive was cured. Four layers of ePTFE tape were wrapped around each end of the cover and catheter shaft, and additional adhesive was applied and cured.

[0064] The cover and balloon were inflated to approximately 6 atmospheres and inspected for leaks or defects. After deflation, the cover and balloon were set in a pleating die-stamping machine. The cover and balloon were then inflated to approximately 2 atmospheres, and the pleating die-stamping machine was used in parallel with a vacuum of approximately -0.5 atmospheres. Next, the cover and balloon were set in a compression die-stamping machine that rotates the pleats radially.

[0065] A stent graft, consisting of a stainless steel stent ring and an ePTFE lumen and luminal cover, was positioned coaxially on the balloon and cover, and then lightly compressed. The cover, balloon, and stent were then compressed to the desired profile for delivery into the patient's body.

[0066] It will be apparent to those skilled in the art that various modifications and alterations can be made to this disclosure without departing from its intent or scope. Accordingly, this disclosure is inclusive of such modifications and alterations, as long as they remain within the scope of the attached claims and their equivalents.

[0067] Similarly, many features and advantages have been described in the following description, including details of the structure and function of the apparatus and / or method, and various alternatives. The disclosures herein are intended to be illustrative only and are not intended to be exhaustive. It will be apparent to those skilled in the art that various modifications are possible, including combinations, particularly with respect to structure, materials, elements, components, shape, size, and arrangement of parts, within the broad and general meanings of the terms used in the appended claims. To the extent that such modifications do not deviate from the spirit and scope of the appended claims, such modifications shall be incorporated herein.

Claims

[Claim 1] Catheter tube; A balloon having length and outer surface, and connected to a catheter tube; and A catheter assembly comprising an outer cover that encloses the balloon and has a multilayer structure comprising an outer layer containing a composite layer having a porous polymer and an elastomer component absorbed by the porous polymer, and an inner layer of porous polymer in which the elastomer component has not been absorbed, wherein the outer cover has an inner surface and an outer surface, and at least a portion of the inner surface of the outer cover is non-adherent to the outer surface of the balloon after inflation.

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