Expandable sheath tube and gasket thereof

Abstract

An expandable sheath body for a sheath assembly. The sheath body has a tubular frame with a lumen therein. There is a void in the frame. The frame is expandable to a larger diameter and collapsible to a smaller diameter, and is also flexible. The sheath barrel body has an inner liner formed on a surface of a lumen defined by the tubular frame and an outer liner formed on an outer surface of the frame. The inner layer of the inner liner and the inner layer of the multi-layer outer liner can be made of expanded polytetrafluoroethylene. The expanded polytetrafluoroethylene may be infused with silicone oil to increase lubricity.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 341,252, filed May 12, 2022, the disclosure of which is incorporated herein by reference. Background Art

[0003] An intracardiac heart pump assembly can be surgically or percutaneously introduced into the heart and used to deliver blood from one location in the heart or circulatory system to another location in the heart or circulatory system. For example, when deployed in the heart, an intracardiac pump can pump blood from the left ventricle of the heart into the aorta, or pump blood from the inferior vena cava into the pulmonary artery. The intracardiac pump can be powered by a motor (and accompanying drive cable) located outside the patient's body or by an onboard motor located inside the patient's body. Some intracardiac blood pump systems can run in parallel with the natural heart to supplement cardiac output and partially or completely unload components of the heart. Examples of such systems include Series equipment (Abiomed, Inc., Danvers Mass).

[0004] In a common method, the intracardiac blood pump is inserted by a catheterization procedure through the femoral artery using an introducer sheath, which can be a peel-away introducer sheath. Alternatively, the sheath can be inserted into other locations such as the femoral vein or any route for delivering the pump to support the left or right side of the heart.

[0005] The introducer sheath can be inserted into the femoral artery through an arteriotomy, thereby creating an insertion path for the pump assembly. Then, a portion of the pump assembly is advanced through the lumen of the introducer sheath and advanced into the artery. The required size of the arteriotomy is a matter of great concern. Therefore, expandable introducer sheaths have been developed so that a smaller arteriotomy opening is required to accommodate the sheath and the medical device passing therethrough. Therefore, improvements in expandable introducer sheaths are also being sought. Summary of the invention

[0006] According to some aspects, expandable introducer sheath (introducer sheath) comprises the liner (liner) that is positioned in the sheath, and this liner can be constructed and arranged to reduce the friction when medical device passes through the sheath. Friction reduction realizes that medical device is easier to pass through the sheath, and utilizes this easy to pass through to provide at least nominal smaller diameter sheath, it needs at least nominal smaller, the arteriotomy opening (arteriotomyopening) that the sheath is introduced into the patient body through. " diameter " used herein is used to describe the distance from one side to the other side of introducer sheath or medical device. Diameter is not intended to imply that introducer sheath or introducer sheath chamber or device cross section are accurately circular. In some embodiments, liner is formed by polytetrafluoroethylene (ePTFE).

[0007] The present invention describes an introducer sheath assembly having a tubular frame having a lumen therein, wherein the tubular frame is configured to temporarily expand from a first diameter to a second, larger diameter when a portion of a medical device having a diameter greater than the first diameter passes through the tubular frame. The introducer sheath assembly also has a liner adjacent to an inner surface of the tubular frame, wherein the liner is formed of expanded polytetrafluoroethylene (ePTFE); and a hub coupled to a proximal end of the tubular frame, the hub including a hemostatic valve.

[0008] In one aspect, the ePTFE liner is attached to the inner surface of the tubular frame. In another aspect, a primer is formed between the ePTFE liner and the inner surface of the cavity defined by the tubular frame. In another aspect, the introducer sheath assembly has an outer liner formed on the outer surface of the tubular frame. The tubular frame can be made of braided nitinol tube or laser cut hypotube.

[0009] In one aspect, the outer liner is made of thermoplastic polyurethane or expanded polytetrafluoroethylene. The outer liner can be a single layer or multiple layers. In one aspect, the outer liner has two layers. The first layer can be formed on the outer surface of the frame, and the first layer can be made of thermoplastic polyurethane. The second layer of the two layers of the outer liner is formed on the first layer, and the second layer can be made of polytetrafluoroethylene.

[0010] The present invention also discloses an expandable sheath body. The expandable sheath body has a tubular frame having a cavity therein, the frame having a gap, wherein the frame is expandable to a larger diameter and contractible to a smaller diameter, and is also flexible. The expandable sheath body has an inner liner and an outer liner, the inner liner is formed on the surface of the cavity defined by the tubular frame, and the outer liner is formed on the outer surface of the frame. In one aspect, a primer is formed between the inner liner and the surface of the cavity defined by the tubular frame. In a further aspect, a primer is formed between the outer liner and the outer surface of the frame.

[0011] In another aspect, the frame can be made of braided nitinol tubing or laser cut hypotube. In a further aspect, the inner liner can be made of expanded polytetrafluoroethylene. In another aspect, the expandable sheath can have an outer liner that is made of thermoplastic polyurethane or expanded polytetrafluoroethylene and can be multi-layered. If the outer liner of the expandable sheath is multi-layered, in one aspect, the multi-layer outer liner can have two layers, wherein the first layer is formed on the outer surface of the frame and wherein the first layer includes thermoplastic polyurethane. The second of the two layers of the outer liner is formed on the first layer, wherein the second layer includes expanded polytetrafluoroethylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A sheath assembly is illustrated.

[0013] Figure 2 A first sheath body is illustrated, which is configured for use in a sheath assembly, such as Figure 1 The sheath assembly is shown.

[0014] Figure 3 It is taken along the AA axis. Figure 2 A cross-sectional view of the sheath barrel body.

[0015] Figure 4 yes Figure 3 Schematic diagram of the side wall portion A of the sheath barrel body.

[0016] Figure 5 A second sheath body is illustrated, which is configured for use in a sheath assembly, such as Figure 1 The sheath assembly is shown.

[0017] Figure 6 It is taken along the BB axis. Figure 5 A cross-sectional view of the sheath barrel body.

[0018] Figure 7 yes Figure 6 Schematic diagram of the side wall portion B of the sheath barrel body.

[0019] Figure 8 A third sheath body is illustrated, which is configured for use in a sheath assembly, such as Figure 1 The sheath assembly is shown.

[0020] Fig. 9 It is taken along the CC axis. Figure 8 A cross-sectional view of the sheath barrel body.

[0021] Fig.10 yes Fig. 9 Schematic diagram of the side wall portion C of the sheath barrel body. DETAILED DESCRIPTION

[0022] Aspects of the present disclosure are described in detail with reference to the accompanying drawings, wherein the same reference numbers identify similar or identical elements. It should be understood that the disclosed aspects are merely examples of the present disclosure, which can be implemented in various forms. Well-known functions or structures are not described in detail to avoid unnecessary details covering up the present disclosure. Therefore, the specific structural and functional details disclosed herein will not be interpreted as limiting, but only as a basis for claims and as a representative basis to teach those skilled in the art to apply the present disclosure in various ways with substantially any appropriately specific structure.

[0023] In order to provide an overall understanding of the systems, methods, and devices described herein, certain exemplary embodiments will be described. Although the devices and features thereof described herein are specifically described with respect to use in conjunction with an intracardiac heart pump system, it should be understood that all of the components and other features outlined below may be combined with one another in any suitable manner and may be adapted and applied to other types of medical devices, such as electrophysiology studies and catheter ablation devices, angioplasty and stenting devices, angiographic catheters, peripherally inserted central catheters, central venous catheters, midline catheters, peripheral catheters, inferior vena cava filters, abdominal aortic aneurysm treatment devices, thrombectomy devices, TAVR delivery systems, cardiac therapy and heart assist devices, including balloon pumps, heart assist devices implanted using surgical incisions, and any other venous or arterial based introductory catheters and devices.

[0024] Since commercially available introducer sheaths are generally not radially expandable, the inner diameter of the introducer sheath must always be large enough to accommodate the largest diameter portion of the pump assembly, such as the pump head, even if other portions of the pump assembly, such as the catheter, have significantly smaller diameters. In this example, the introducer requires a relatively large vessel opening (e.g., an arteriotomy) to allow the pump catheter to pass through the introducer sheath and into the vessel, which can complicate closure of the arteriotomy at the end of the procedure.

[0025] Some medical introducers for inserting applications other than heart pumps have an expandable sheath body that can expand to accommodate a larger diameter percutaneous device to enter the patient's vascular system (vascular system, vasculature) through a smaller diameter sheath cavity. Generally, these introducer sheaths have an inner diameter less than the outer diameter of the device being introduced when inserted. The introducer sheath expands to allow the device to pass through the introducer sheath and enter the vascular system, and then can relax back to its smaller diameter state after the larger diameter portion of the device passes. In the current industry state, these expandable introducers require unique expandable features, such as longitudinal folds or creases or cavities for injecting fluids (such as saline), to be converted from a compressed state to an expanded state. Therefore, this commercially available expandable sheath is generally fully flexible, and therefore does not provide any rigidity in its structure, thereby causing kinking or buckling during insertion or withdrawal of a percutaneous medical device. Although expandable sheaths provide many benefits, improvements in design and performance are still being sought.

[0026] System, method and device described herein provide expandable sheath body, it is configured for expandable sheath assembly, for inserting medical device (for example, intracardiac heart pump) into blood vessel through vascular hole.Contriver has recognized and understood, expandable sheath system can provide many benefits compared with conventional non-expandable sheath.For example, by allowing temporary expansion in medical device insertion process, expandable sheath can allow to realize smaller vascular hole size (i.e. arteriotomy size) compared with non-expandable sheath to deliver medical device, the inner diameter of non-expandable sheath must be at least as large as the maximum diameter of medical device to be passed therein.However, the inventor further recognizes that, due to the reduction of the cavity cross-sectional area of ​​expandable sheath (for example, reduced to the maximum diameter part of nominal or resting cross-sectional area less than medical device passing therein), medical device may become more difficult to pass introducer sheath in the process of inserting and / or removing medical device.Therefore, system, method and device described herein provide such expandable sheath system: it has reduced insertion and / or removal force, and this allows further reduced sheath diameter and correspondingly smaller vascular hole size.

[0027] Expandable sheath tube main body described herein can be used for the expandable sheath tube assembly comprising expander assembly.As described, expandable sheath tube main body has inner surface and outer surface, and inner surface is limited in the cavity extending between the near end and the distal end of sheath tube main body.Optionally, except expandable sheath tube main body, expandable sheath tube assembly can also include hemostasis needle (hemostasisstylet).For coronary artery disease (CAD) and peripheral artery disease patient (performance arterial calcification and tortuosity, cause introducer sheath tube and catheter to deliver difficulty), expandable sheath tube assembly (comprising expandable sheath tube main body, expander assembly and optional hemostasis needle) is particularly beneficial relative to existing expandable sheath tube assembly.

[0028] The expandable sheath assembly with sheath body described herein is easier to insert than traditional assembly, because its insertion profile is reduced, flexibility is increased, friction is reduced, and the risk of kinking under load is reduced. The reduced insertion profile can reduce the complication related to insertion, reduce the stretching and load of blood vessel opening, and reduce the risk of limb ischemia. The structure of sheath body described herein provides sufficient axial rigidity, so that the sheath body can be advanced in cavity (such as blood vessel) but resist buckling, keep bending flexibility and kink resistance simultaneously, and reduce friction to prevent "finger trap". In addition, the improvement that the structure of sheath body described herein provides relative to existing introducer sheath body is to have inner lining or outer lining or at least one of the two, wherein each lining is constructed and arranged to reduce the required force of expansion sheath body (compared with the required force of sheath with coating without any biasing with expansion), and when at least sheath body has inner lining as described herein, the insertion and removal force of device is minimized by reducing the friction between sheath body and the device inserted therein.

[0029] The sheath barrel body can expand between different states to accommodate (adapt, accommodate) medical devices when they pass through the sheath barrel. For example, the sheath barrel body can be stretched (generally using an expander) for insertion in a first smaller diameter state, and relax to a second larger diameter state after being in a desired position to allow a portion of the medical device to pass through the cavity, and the cross-sectional area of ​​the portion of the medical device is greater than the cross-sectional area of ​​the cavity in the first state. In different configurations, the sheath barrel body diameter expands between a resting state (when the sheath barrel is deployed in its desired position) and a larger diameter state (when the medical device passes through the sheath barrel body). After the medical device passes through the sheath barrel, the sheath barrel can be retracted (recoil) or otherwise relaxed and returned to a resting state with a smaller diameter. In any configuration, the expandable sheath barrel assembly with the sheath barrel body described herein does not require additional elements relative to the standard introducer assembly. That is, the assembly described herein has at least the following (features): i) no external balloon; ii) the expandable sheath barrel body is not folded; iii) no second sheath barrel is used for delivery. This simplifies use of an expandable sheath assembly having a sheath body as described herein (eg, requires fewer steps, takes less time).

[0030] In addition, the instantaneous expansion of the sheath body from the extended state to the relaxed state (or from the relaxed state to the expanded state) reduces the size of the opening (e.g., arteriotomy) required when the sheath is inserted into the patient's vascular system. Minimizing the time amount of the sheath body in the expanded state also reduces the damage to the blood vessel wall, otherwise the sheath body may cause damage to the blood vessel wall when the expanded state is maintained for a long time. In addition, receiving the required opening of the sheath body in the relaxed or shrunken state reduces the risk of thrombosis blocking the blood vessel of the sheath body.

[0031] As described above, the expandable sheath can deliver the sheath body to the patient's vascular system with a smaller profile - if it is kept axially stretched (pre-stretched (drawn down)) before insertion. This has the following major benefits: i) pre-stretching to a smaller insertion profile to minimize insertion-related complications (i.e., bleeding, vascular damage, high insertion force); ii) maintaining a "soft" sheath body and instantaneous expansion to interact at the arteriotomy site to allow small hole closure and bleeding to be minimized - due to the minimization of vascular retraction during use. However, it should be understood that some sheath configurations according to the present disclosure may not be pre-stretched before insertion into a blood vessel. For example, the sheath can be inserted and maintained in a blood vessel in a relaxed state, and can then be instantaneously expanded to a larger diameter when the medical device passes through the sheath, as described above.

[0032] Figure 1 Shown is a sheath tube assembly 100 according to aspects of the disclosed technology. The sheath tube assembly 100 has a socket 110, which locks the sheath tube in place after being inserted. The socket 110 works with a cover 120 to fix the sheath tube body 130 in place. The socket 110 also has a ratchet 112 (only one of which is visible) to assist the attachment of the socket 110 to the expander socket 230. The butterfly / suture pad 140 is configured to assist the attachment of the sheath tube assembly 100 to the patient (e.g., by suturing the assembly to the patient). In the current description, the proximal end of the assembly is located at the socket / cover end, and the distal end of the assembly is located at the distal end. Fluid can be introduced into the assembly by side arm passage 160, and the fluid flow entering the device can be controlled by a cock 170. A hemostatic valve (not shown) may also be included in the socket 110, and the hemostatic valve is configured to prevent blood from leaking outside the patient's body during insertion and / or removal of an intracardiac blood pump or other components. Although any suitable hemostatic valve may be used with the sheath assembly described herein, examples are described and exemplified in U.S. Patent Application No. 17 / 097,582, filed on November 13, 2020, and published on May 20, 2021 as U.S. Patent Publication No. 20210146111, which is incorporated herein by reference. Additionally, in some embodiments, the receptacle 110 may include a foam insert (not shown) located proximal to the hemostatic valve, which may be impregnated with a lubricant such as silicone so that the assembly will be lubricated when inserted through the foam and into the sheath body 130.

[0033] Figure 2-10Various sheath tube body structures configured to be used in conjunction with the sheath tube assembly 100 according to aspects of the disclosed technology are illustrated. In all aspects, the expandable sheath tube body 200, 300, 400 comprises a multilayer structure having a circumferential frame 202, 302, 402 between an inner liner 204, 304, 404 and an outer liner 206, 306, 406. The frame 202, 302, 402 can be formed with any suitable material. In order to provide an expandable frame with suitable kink resistance, the expandable frame 202, 302, 402 can be a braided material. Alternatively, the frame can be a hypotube, wherein a gap is introduced by laser cutting. The hypotube is generally made of metal. In further aspects, the braided material is a metal material having both elasticity and shape memory properties. An example of a suitable braided material is a braid formed by nitinol. In some aspects according to the present disclosure, the frames 202, 302, 402 are expandable braided frames comprised of strands of a flexible metal such as nitinol. The frames 202, 302, 402 may have an expansion mechanism that assists the frame in expanding and / or contracting. For example, the strands of the braided frame may be configured to have a bias to expand and / or contract from a resting position. According to some embodiments, the expansion mechanism allows the strands of the braided frame to slide relative to each other as the frame expands and contracts.

[0034] Each of the inner liner 204, 304, 404 and the outer liner 206, 306, 406 is a low friction layer that is applied to the frame 202, 302, 402 for mitigating (i.e., reducing) the force required to insert and remove a device (e.g., an intracardiac heart pump) by reducing the frictional forces induced during the insertion and removal process. In addition, the inner liner 204, 304, 404 and the outer liner 206, 306, 406 can allow the sheath to expand with relatively less force than would be required to expand a sheath without any liner. Figure 2-10 As shown, the inner liner 204, 304, 404 and the outer liner 206, 306, 406 are applied (or bonded) to the inner surface 208, 308, 408 of the frame 202, 302, 402 and the outer surface 210, 310, 410 of the frame 202, 302, 402, respectively - using a thermoforming process (also known as lamination). Since the frame is braided in these embodiments, the inner layer and the outer layer can be bonded to each other through the interstices of the braid. Therefore, the inner liner and outer liner materials are selected to expand and contract in coordination with the sheath frame.

[0035] like Figure 3-4 , Figure 6-7 and Figure 9-10As shown, the sheath body 200, 300, 400 may further include an inner bottom rubber layer 212, 312, 412 between the inner surface 208, 308, 408 of the frame 202, 302, 402 and the inner liner 204, 304, 404, and an outer bottom rubber layer 214, 314, 414 between the outer surface 210, 310, 410 of the frame 202, 302, 402 and the outer liner 206, 306, 406. The inner and outer adhesive layers 212, 312, 412 and 214, 314, 414 are provided to improve adhesion of the inner and outer surfaces 208, 308, 408 and 210, 310, 410 of the frames 202, 302, 402 to the inner and outer pads 204, 304, 404 and 206, 306, 406, respectively.

[0036] Inner liner 204,304,404 is made of polymer material. In one aspect, polymer material is expanded polytetrafluoroethylene (ePTFE). The characteristic of ePTFE provides smooth, soft and flexible inner surface to the inner liner 204,304,404 of sheath body 200,300,400, which reduces the risk of clot formation and reduces the friction and adhesion when the device is inserted through the expandable sheath or the device is removed from the expandable sheath. For example, ePTFE inner liner 204,304,404 provides a low friction coefficient surface contacted with the device pushed through the sheath body, thereby reducing the relevant friction. In the present disclosure, outer liner 206,306,406 can be composed of a single layer or multilayer polymer material (e.g., a multilayer liner), as described in more detail below.

[0037] Primers suitable for applying an ePTFE liner to a surface are well known and will not be described in detail here. ePTFE is hydrophobic, so a suitable primer takes this into account. An example of a suitable primer is one that produces amine groups on its surface (e.g., co-deposition of polyethyleneimine (PEI) and polydopamine). Surface treatments such as plasma immersion and oxygen plasma have been used to create surfaces suitable for ePTFE deposition. Reference Figure 2-4 In a first aspect, an ePTFE inner liner 204 is applied to an inner surface 208 of a braided framework 202, as described above. Optionally, the framework 202 can be formed by patterning a hypotube having a lumen therein. In one aspect, the hypotube is patterned by laser cutting. The pattern introduced into the hypotube is provided to control axial expansion, radial expansion, and / or compression of the lumen.

[0038] exist Figure 2-4In the current aspect of the invention, the outer liner 206 is also made of a polymer material; in this aspect, the polymer material used to form the outer liner 206 can be the same or different from the above-mentioned ePTFE inner liner 204. In the exemplary aspect, the outer liner 206 is made of thermoplastic polyurethane (TPU). The characteristics (or properties) of ePTFE and TPU are respectively beneficial to provide a smooth, soft and flexible inner and outer surface for the sheath body 200 to reduce friction and adhesion when inserting or removing the device from the expandable sheath, thereby requiring relatively small forces to insert and remove the device (e.g., an intracardiac heart pump)-compared with the forces required to insert and remove the device by the sheath body without any liner. In addition, the smooth surface of the TPU outer liner 206 beneficially reduces the risk of clots forming on the surface of the expandable sheath body 200. In addition, in some cases, the inner liner formed by ePTFE can allow some liquids to pass through the inner liner permeability, and a liquid-impermeable material can be selected for the outer layer. Such a configuration can help reduce or eliminate the undesirable leakage or seepage of the sheath body, and can help maintain hemostasis. However, it should be understood that the introducer sheath described herein is not limited to a sheath comprising a liquid-impermeable outer layer. For example, in some embodiments, a sheath comprising only an ePTFE inner liner can provide a sufficient degree of liquid impermeability to avoid leakage or seepage and maintain hemostasis during use.

[0039] In a further aspect, the outer liner can have an outer (eg, TPU) layer that can be partially formed into the microporous structure of the ePTFE.

[0040] refer to Figure 5-7 In a second aspect, an ePTFE inner liner 304 is applied to an inner surface 308 of a braided frame 302, as described above. As in the first aspect described above, optionally, the frame 302 can be formed by patterning a hypotube having a cavity therein. The hypotube is patterned by laser cutting. The pattern introduced into the hypotube is provided to control the axial expansion, radial expansion and compression of the cavity. An inner bottom rubber layer 312 and an outer bottom rubber layer 314 are formed on the inner and outer surfaces of the frame 302.

[0041] In the present aspect, the inner liner 304 and the outer liner 306 are made of the same material. For example, the inner liner 304 and the outer liner 306 are made of ePTFE. Similar to the first aspect, the properties of ePTFE beneficially provide the sheath body 300 with smooth, soft and flexible inner and outer surfaces to reduce friction and adhesion when inserting the device through the expandable sheath or removing the device from the expandable sheath, thereby requiring relatively less force to insert and remove the device (e.g., an intracardiac heart pump) - compared to the force required to insert and remove the device by a sheath body without any liner. In addition, the smooth surface of the ePTFE outer liner 306 beneficially reduces the risk of clots forming on the surface of the expandable sheath body 300.

[0042] refer to Figure 8-10 In a third aspect, an ePTFE inner liner 404 is applied to the inner surface 408 of the braided frame 402, as described above. A primer layer 412 is interposed between the inner surface 408 of the frame 402 and the ePTFE inner liner 404. In the current aspect, the outer liner 406 has a multi-layer configuration and is therefore made of a variety of polymer materials. In an exemplary aspect, the outer liner 406 may have an ePTFE layer 416 and a TPU layer 418. Fig. 9 and Fig.10 As can be seen, the ePTFE layer 416 of the outer liner 406 is bonded to the outer surface 410 of the frame 402 (wherein the primer layer 414 is between the multilayer outer liner 406 and the frame 402). The TPU layer 418 is applied to the top of the ePTFE layer 416 to improve the biocompatibility of the ePTFE layer 416. As in the first and second aspects, the ePTFE inner liner 404 and the outer multilayer liner 406 are respectively beneficial to provide a smooth, soft and flexible inner and outer surface for the sheath body 400 to reduce friction and adhesion when inserting the device through the expandable sheath or removing the device from the expandable sheath, thereby requiring relatively less force to insert and remove the device (e.g., an intracardiac heart pump)-compared to the force required to insert and remove the device by the sheath body without any liner. In addition, the smooth surface of the multilayer outer liner 406 beneficially reduces the risk of clots forming on the surface of the expandable sheath body 400.

[0043] In the above aspects, the sheath body 200, 300, 400 may include silicone oil impregnated in the ePTFE inner liner 204, 304, 404 to reduce or prevent air, water and / or blood from penetrating the ePTFE inner liner 204, 304, 404. Silicone oil also reduces the friction coefficient of ePTFE, which can be reduced by up to half. Silicone oil is introduced into the ePTFE liner by applying it to the surface to be in contact with the ePTFE inner liner. The silicone oil is then wicked into the porous ePTFE. When silicone oil is applied to the surface to wick into the ePTFE, the viscosity of the silicone oil is low enough so that the silicone oil wicks through the ePTFE and is retained by the microporous structure of the hydrophobic ePTFE to provide an elastic lubricated surface. The ability of silicone oil to be retained by ePTFE is indirectly proportional to the density and pore size of ePTFE (i.e., for ePTFE with lower density (i.e., more porous ePTFE), a higher viscosity is required to present similar silicone oil retention). To achieve the desired lubricating effect and obtain the desired silicone oil retention, for example, for ePTFE having a density of about 0.4 g / cc, the viscosity of the silicone oil may be 350 cP. Viscosities greater than 350 cP do not provide the same lubricating effect. For example, for ePTFE having a density in the order of those above, a viscosity of 1000 cP provides only half the lubricating effect provided by a viscosity of 350 cP.

[0044] In the above aspects, the inner liner 204, 304, 404 has a tubular shape and extends the entire length of the sheath body 200, 300, 400, as shown in FIG. Figure 2 , 5 8. The outer liner 206, 306, 406 also has a tubular shape and extends the length of the elongated portion 201, 301, 401 of the sheath body 200, 300, 400. Therefore, the outer liner 206, 306, 406 extends between the proximal end of the sheath body 200, 300, 400 and the demarcation point 203, 303, 403, which is the site where the outer surface of the sheath body 200, 300, 400 begins to taper in both the inner diameter and the outer diameter. As shown in the example, the tapering portion is followed by a smaller diameter portion, whose inner diameter and outer diameter are constant. As shown in the example, the outer liner 206, 306, 406 does not extend on the tapering portion or the constant diameter / smaller diameter (portion).

[0045] Although the inner diameter and outer diameter of the sheath barrel body depend largely on design selection, the inner diameter of the main sheath barrel body is considered to be about 4mm. "About" used herein means the plus or minus 25% of the value, or according to the understanding of the term in the applicable context by those skilled in the art. The inner liner 204,304,404 and the outer liner 206,306,406 can have any suitable thickness. In one aspect, the thickness of each of the inner liner 204,304,404 and the outer liner 206,306,406 is about 0.05mm. The cavity 205,305,405 of the sheath barrel body 200,300,400 can be any suitable size. Preferably, the inner diameter of the cavity 205,305,405 of the sheath barrel body 200,300,400 is 4mm. The tapering portion 207,307,407 of the sheath barrel body 200,300,400 can be any suitable size. Preferably, the length of the tapered portion 207, 307, 407 is between 0.1 mm and 5 mm, and the diameter of the opening 209, 309, 409 at the distal end 211, 311, 411 of the tapered portion 207, 307, 407 is between about 3.7 mm and about 3.9 mm.

[0046] The present invention describes an introducer sheath assembly having a tubular frame having a cavity therein, wherein the tubular frame is configured to temporarily expand from a first diameter to a second, larger diameter when a portion of a medical device having a diameter greater than the first diameter passes through the tubular frame; a liner adjacent to an inner surface of the tubular frame, wherein the liner is formed of expanded polytetrafluoroethylene (ePTFE); and a socket connected to a proximal end of the tubular frame, the socket including a hemostatic valve.

[0047] In one aspect, the ePTFE liner is attached to the inner surface of the tubular frame. In a further aspect, a primer is formed between the ePTFE liner and the inner surface of the cavity defined by the tubular frame. In another aspect, an outer liner is formed on the outer surface of the tubular frame.

[0048] The frame can be made of braided nitinol tubes and laser cut hypotubes. The outer liner can be made of a thermoplastic polyurethane, such as expanded polytetrafluoroethylene. In one aspect, the outer liner is multilayered. For example, the outer liner can have two layers, wherein a first layer can be formed on an outer surface of the frame, and wherein the first layer can be a thermoplastic polyurethane. A second layer of the two layers of the outer liner can be formed on the first layer, wherein the second layer comprises expanded polytetrafluoroethylene.

[0049] The present invention also describes an expandable sheath body having a tubular frame having a cavity therein, the frame having a void, wherein the frame is expandable to a larger diameter and contractible to a smaller diameter and is flexible; an inner lining formed on the surface of the cavity defined by the tubular frame; and an outer lining formed on the outer surface of the frame.

[0050] In one aspect, the sheath body may have a primer formed between an inner liner and a surface of a lumen defined by a tubular frame. The primer may be formed between an outer liner and an outer surface of the frame. The frame may be a braided nitinol tube or a laser cut hypotube.

[0051] In one aspect of the sheath body, the inner liner can be made of expanded polytetrafluoroethylene. The outer liner can be made of thermoplastic polyurethane, such as expanded polytetrafluoroethylene.

[0052] In a further aspect, the outer liner can be multi-layered. For example, the outer liner can have two layers, wherein the first layer can be formed on the outer surface of the frame, and wherein the first layer can be thermoplastic polyurethane. The second layer of the two layers of the outer liner can be formed on the first layer, and the second layer can be formed of expanded polytetrafluoroethylene.

[0053] An introducer sheath assembly is described herein, having a tubular frame having a lumen therein, wherein the tubular frame is configured to temporarily expand from a first diameter to a second, larger diameter when a portion of a medical device having a diameter greater than the first diameter passes through the tubular frame. The introducer sheath has a liner adjacent to an inner surface of the tubular frame, wherein the liner is formed of expanded polytetrafluoroethylene (ePTFE); and a socket coupled to a proximal end of the tubular frame, the socket including a hemostatic valve.

[0054] In one aspect, the ePTFE liner is attached to the inner surface of the tubular frame. According to the above aspects, a primer can be formed between the ePTFE liner and the inner surface of the cavity defined by the tubular frame. In any of the above aspects, an outer liner is formed on the outer surface of the tubular frame. In any of the above aspects, the frame is selected from a braided nitinol tube and a laser cut hypotube. The frame can be made of nitinol and the outer liner can be made of thermoplastic polyurethane or expanded polytetrafluoroethylene. In one aspect, the outer liner is multilayered. In another aspect, the outer liner can have two layers, wherein the first layer is formed on the outer surface of the frame, wherein the first layer includes thermoplastic polyurethane. In a further aspect, the second layer of the two layers of the outer liner is formed on the first layer, wherein the second layer includes expanded polytetrafluoroethylene.

[0055] The present invention also describes an expandable sheath body having a tubular frame having a cavity therein, the frame having a void, wherein the frame is expandable to a larger diameter and contractible to a smaller diameter, and is also flexible. The sheath body may have an inner liner formed on the surface of the cavity defined by the tubular frame and an outer liner formed on the outer surface of the frame.

[0056] In one aspect, a primer is formed between the inner liner and the surface of the cavity defined by the tubular frame. In a further aspect, a primer is formed between the outer liner and the outer surface of the frame. In the above aspects, the expandable sheath body may have a frame made of a braided nitinol tube or a laser cut hypotube. In one aspect, the frame is made of nitinol. In the above aspects, the expandable sheath body may have an inner liner made of expanded polytetrafluoroethylene. In the above aspects, the outer liner may be made of thermoplastic polyurethane. According to the above aspects, the outer liner may be made of expanded polytetrafluoroethylene. The outer liner may be multilayered. In a further aspect, the outer liner may have two layers, wherein the first layer is formed on the outer surface of the frame, wherein the first layer includes thermoplastic polyurethane. In a further aspect, the second layer of the two layers of the outer liner is formed on the first layer, wherein the second layer includes expanded polytetrafluoroethylene.

[0057] Based on the foregoing and with reference to the various drawings, those skilled in the art will appreciate that certain modifications may also be made to the present disclosure without departing from its scope. Although several embodiments of the present disclosure are shown in the drawings, it is not intended that the present disclosure be limited thereto, because it is intended that the scope of the present disclosure be as wide as the art allows, and the specification should be understood in the same manner. Therefore, the above description should not be considered as limiting, but merely as an example of a specific embodiment. Those skilled in the art will foresee other modifications within the scope and spirit of the appended claims.

Claims

1. Introducer sheath assembly, include: a tubular frame having a lumen therein, wherein the tubular frame is configured to temporarily expand from a first diameter to a second, larger diameter, the expansion occurring when a portion of a medical device having a diameter greater than the first diameter passes through the tubular frame; a liner adjacent an inner surface of the tubular frame, wherein the liner is formed of expanded polytetrafluoroethylene (ePTFE); as well as A socket is coupled to the proximal end of the tubular frame, the socket including a hemostatic valve.

2. The introducer sheath assembly of claim 1, wherein an ePTFE liner is attached to an inner surface of the tubular frame.

3. An introducer sheath assembly according to any one of claims 1 and 2, wherein a primer is formed between the ePTFE liner and the inner surface of the cavity defined by the tubular frame.

4. The introducer sheath assembly according to any one of claims 1 to 3, wherein an outer liner is formed on an outer surface of the tubular frame.

5. The introducer sheath assembly of any one of claims 1 to 4, wherein the frame is selected from a braided nitinol tube and a laser cut hypotube.

6. The introducer sheath assembly of any one of claims 1 to 5, wherein the frame is made of Nitinol.

7. An introducer sheath assembly according to any one of claims 4 to 6, wherein the outer liner is made of thermoplastic polyurethane.

8. The introducer sheath assembly according to any one of claims 4 to 6, wherein the outer liner is made of expanded polytetrafluoroethylene.

9. An introducer sheath assembly according to any one of claims 4 to 8, wherein the outer liner is multi-layered.

10. The introducer sheath assembly according to any one of claims 4 to 9, wherein the outer liner comprises two layers, wherein a first layer is formed on an outer surface of the frame, wherein the first layer comprises thermoplastic polyurethane.

11. The introducer sheath assembly of claim 10, wherein a second layer of the two layers of the outer liner is formed on the first layer, wherein the second layer comprises expanded polytetrafluoroethylene.

12. Expandable sheath body, include: a tubular frame having a lumen therein, the frame having a void, wherein the frame is expandable to a larger diameter and contractible to a smaller diameter, and is also flexible; an inner liner formed on a surface of the cavity defined by the tubular frame; as well as An outer liner is formed on an outer surface of the frame.

13. The expandable sheath body according to claim 12, wherein a primer is formed between the inner liner and the surface of the cavity defined by the tubular frame.

14. The expandable sheath body according to claim 12, wherein a primer is formed between the outer liner and the outer surface of the frame.

15. The expandable sheath body of any one of claims 12-14, wherein the frame is selected from a braided nitinol tube and a laser cut hypotube.

16. The expandable sheath body of claim 15, wherein the frame is made of Nitinol.

17. The expandable sheath body according to any one of claims 12-16, wherein the inner liner is made of expanded polytetrafluoroethylene.

18. The expandable sheath body of any one of claims 12-17, wherein the outer liner is made of thermoplastic polyurethane.

19. The expandable sheath body of any one of claims 12-17, wherein the outer liner is made of expanded polytetrafluoroethylene.

20. The expandable sheath body of any one of claims 12-15 and 17, wherein the outer liner is multi-layered.

21. The expandable sheath body of claim 20, wherein the outer liner comprises two layers, wherein a first layer is formed on an outer surface of the frame, wherein the first layer comprises thermoplastic polyurethane.

22. The expandable sheath body of claim 21, wherein a second of the two layers of the outer liner is formed on the first layer, wherein the second layer comprises expanded polytetrafluoroethylene.

23. The expandable sheath of any one of claims 17-19, wherein the expanded polytetrafluoroethylene is infused with silicone oil.

24. The expandable sheath of any one of claims 23, wherein the expanded polytetrafluoroethylene is infused with the silicone oil by wicking the silicone oil from a surface on which the expanded polytetrafluoroethylene layer is disposed.

25. The expandable sheath of claim 23, wherein the density of the expanded polytetrafluoroethylene is about 0.4 g / cc and the viscosity of the silicone oil is about 350 cP.

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