Expandable sheath with split inner member and method of making same

Abstract

Disclosed herein are introducer sheaths (100,300) and methods of manufacturing and using the same. The disclosed sheath includes an inner liner (306) comprising a sheet (308) wound in a spiral configuration such that a second edge (312) of the sheet overlays a first edge of the sheet. An angled portion (326) of the second edge facilitates formation of the tapered or flared section (328) of the inner liner when the sheet is wound in the spiral configuration. When wound in the spiral configuration, the inner liner is centered about a central axis of sheath.

Description

EXPANDABLE SHEATH WITH SPLIT INNER MEMBER AND METHOD OF MAKING SAMECROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 717,790, filed November 7, 2024, the contents of which is incorporated herein by reference in its entirety.FIELD

[0002] The present application is directed to an expandable sheath and introducer usable and / or for use with catheter-based technologies for repairing and / or replacing heart valves, as well as for delivering an implant, such as a prosthetic valve to a heart via the subject’s vasculature.BACKGROUND

[0003] Endovascular delivery catheter assemblies are used to implant prosthetic devices, such as a prosthetic valve, at locations inside the body that are not readily accessible by surgery or where access without invasive surgery is desirable. For example, aortic, mitral, tricuspid, and / or pulmonary prosthetic valves can be delivered to a treatment site using minimally invasive surgical techniques.

[0004] An introducer sheath can be used to safely introduce a delivery apparatus into a patient’s vasculature (e.g., the femoral artery). An introducer sheath generally has an elongated sleeve that is inserted into the vasculature and a housing that contains one or more sealing valves that allow a delivery apparatus to be placed in fluid communication with the vasculature with minimal blood loss. A conventional introducer sheath typically requires a tubular loader to be inserted through the seals in the housing to provide an unobstructed path through the housing for a valve mounted on a balloon catheter. A conventional loader extends from the proximal end of the introducer sheath, and therefore decreases the available working length of the delivery apparatus that can be inserted through the sheath and into the body.

[0005] Conventional methods of accessing a vessel, such as a femoral artery, prior to introducing the delivery system include dilating the vessel using multiple dilators or sheaths that progressively increase in diameter. This repeated insertion and vessel dilation can increase the amount of time the procedure takes, as well as the risk of damage to the vessel.

[0006] Some specific radially expanding intravascular sheaths have been disclosed. Such sheaths tend to have complex mechanisms, such as ratcheting mechanisms that maintain theshaft or sheath in an expanded configuration once a device with a larger diameter than the sheath’s original diameter is introduced.

[0007] However, delivery and / or removal of prosthetic devices and other material to or from a patient still poses a significant risk to the patient. Furthermore, accessing the vessel remains a challenge due to the relatively large profile of the delivery system that can cause longitudinal and radial tearing of the vessel during insertion. The delivery system can additionally dislodge calcified plaque within the vessels, posing an additional risk of clots caused by the dislodged plaque.

[0008] Furthermore, in some instances, it is desirable to vary the diameter of the sheath along its longitudinal central axis. For example, it can be desirable for a portion of the sheath to be flared or tapered to facilitate coupling with the housing. However, forming such a flared or tapered portion can distort the profile of the sheath or interfere with its proper functioning.SUMMARY

[0009] Accordingly, there remains a need in the art for an improved introducer sheath for endovascular systems used for implanting valves and other prosthetic devices. Furthermore, there remains a need for sheath systems that facilitate variations in sheath diameter along the central axis and methods for making and using the same.

[0010] Aspects of the present expandable sheath systems can minimize trauma to the vessel by allowing for temporary expansion of a portion of the introducer sheath to accommodate a delivery system, followed by a return to the original diameter once the delivery system passes through. Some examples can comprise a sheath with a smaller profile than that of known introducer sheaths. Furthermore, example sheaths can reduce the length of time a procedure takes, as well as reduce the risk of a longitudinal or radial vessel tear, or plaque dislodgement because lower push force is required and only one sheath is used, rather than several different sizes of sheaths and / or dilators.

[0011] Furthermore, the present expandable sheaths and corresponding manufacturing and assembly methods help provide a sheath having a diameter that varies along a longitudinal central axis of the sheath. The present example sheaths also helps facilitate coupling between the sheath and a sheath hub assembly by facilitating tapering or flaring of the sheath such that a proximal tapered section of the sheath has a diameter that is greater than a diameter of a distally extending tubular section of the sheath. Furthermore, the present example sheath provides for a smooth transition between the relatively smaller diameter tubular section of thesheath and the relatively larger diameter tapered section of the sheath, thereby further reducing the push forces required to advance the sheath through the vasculature.

[0012] The aspects of the present disclosure are directed to a sheath for introducing a prosthetic device, wherein the sheath can comprise an inner liner. At least a portion of the sheath can be designed or configured to locally expand from a first diameter (rest diameter) to a second diameter (expanded diameter) as the prosthetic device is pushed through a central lumen of the sheath, and then at least partially return to the first diameter once the prosthetic device has passed through.

[0013] In some implementations, the present disclosure provides an expandable sheath for deploying a medical device, the sheath including a proximal end and a distal end and includes an inner liner. The inner liner includes a tapered section extending distally from the proximal end that gradually transitions into a tubular section of the sheath. This configuration can be provided with any one or more of the features described elsewhere herein, in particular with those of the examples described hereafter. However, this somewhat basic configuration can also be provided with any one or more of the features shown in the figures and / or described in conjunction with the figures, either in addition to or alternatively to the features of the examples described hereafter.

[0014] In some examples, the techniques described herein relate to an expandable sheath for delivering a medical device.

[0015] In some examples, the sheath has a proximal end and a distal end and includes an inner liner.

[0016] In some examples, the inner liner includes a sheet having a first edge, a second edge.

[0017] In some examples, the sheet is wound in a spiral configuration and defines a central lumen that extends along a longitudinal central axis of the sheath.

[0018] In some examples, the inner liner is configured to expand from an unexpanded configuration at a first rest diameter drto an expanded configuration at a second expanded diameter deby sliding the first edge of the sheet relative to the second edge of the sheet.

[0019] In some examples, when in the unexpanded configuration the first rest diameter drvaries along the central axis. For example, the inner liner can include a tapered section extending distally from the proximal end that gradually transitions into a tubular section of the sheath.

[0020] In some examples, in at least the unexpanded configuration, the tapered section can have a diameter that is greater than a diameter of the tubular section.

[0021] In some examples, the techniques described herein relate to an expandable sheath for delivering a medical device.

[0022] In some examples, the sheath has a proximal end and a distal end and includes an inner liner.

[0023] In some examples, the inner liner includes a sheet having a longitudinally-extending first edge and a longitudinally -extending second edge.

[0024] In some examples, the inner liner is defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet forming an overlapping portion. The inner surface of the sheet defines a central lumen that extends along a longitudinal central axis of the sheath.

[0025] In some examples, a first straight portion of the second edge extends in a direction generally parallel with the central axis, and an angled portion of the second edge extends circumferentially about the central axis at an angle oblique to the central axis.

[0026] In some examples, the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet.

[0027] In some examples, the inner liner is configured to expand from an unexpanded configuration at a first rest diameter to an expanded configuration at a second expanded diameter by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of the outer surface during application of a radial outward force against the inner surface of the inner liner.

[0028] In some examples, when the inner liner is expanded from an unexpanded configuration at a first rest diameter to an expanded configuration at a second expanded diameter, at least a portion of the first edge of the sheet slides along at least a portion of the inner surface, and at least a portion of the second edge of the sheet slides along at least a portion of the outer surface. In some examples, the inner liner is expanded during application of a radial outward force against at least a portion of the inner surface of the inner liner.

[0029] In some examples, the techniques described herein relate to a sheet for forming an inner liner of a sheath. In some examples, the sheet is defined between a proximal end and a distal end and includes: a first longitudinal edge and a second longitudinal edge opposite the first longitudinal edge; a distal edge at the distal end of the sheet extending between the first longitudinal edge and the second longitudinal edge; a first angled edge extending from the first longitudinal edge at an angle oblique to the first longitudinal edge; a second angled edgeextending from the second longitudinal edge at an angle oblique to the second longitudinal edge: a third longitudinal edge extending from the first angled edge at an angle oblique to the first angled edge; a fourth longitudinal edge extending from the second angled edge at an angle oblique to the second angled edge; and a proximal edge at the proximal end of the sheet extending between the third longitudinal edge and the fourth longitudinal edge.

[0030] In some examples, the techniques described herein relate to a mandrel for cutting a sheath. In some examples, the mandrel includes a shaft having a proximal end, a distal end, and a tubular central region extending therebetween. In some examples, the tubular central region defines a central axis of the shaft. In some examples, the proximal end of the shaft flares radially outward. In some examples, the distal end of the shaft tapers radially inward. In some examples, the shaft defines a groove extending between the proximal end and the distal end. In some examples, a first straight portion of the groove extends generally parallel (e.g., within 10 degrees, within 5 degrees of parallel) with the central axis of the shaft, and an angled portion of the groove extends circumferentially about the central axis at an angle oblique to the central axis.

[0031] In some examples, the techniques described herein relate to a method of manufacturing an inner liner of a sheath. In some examples, the method includes (1) forming a sheet. In some examples, forming a sheet includes: providing an elongated single lumen tubing having an inner surface and an outer surface; and positioning the elongated single lumen tubing about a shaft of a mandrel, the shaft including a proximal end, a distal end, and a tubular central region extending therebetween, the tubular central region defining a central axis of the shaft. In some examples, the shaft defines a groove extending between the proximal end and the distal end. In some examples, a first straight portion of the groove extends generally parallel with the central axis of the shaft, and an angled portion of the groove extends circumferentially about a central axis at an angle oblique to the central axis. In some examples, forming the sheet also includes cutting the single lumen tubing along the first straight portion and angled portion of the groove so as to form a sheet. In some examples, the sheet includes a first longitudinal edge and an opposite second longitudinal edge. In some examples, the method of manufacturing the inner liner also includes (2) coiling the sheet such that the second longitudinal edge extends over the first longitudinal edge, thereby forming the inner liner.

[0032] The foregoing and other features and advantages of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

[0033] Various aspects of the examples described above can be combined based on desired sheath system characteristics.BRIEF DESCRIPTION OF DRAWINGS

[0034] FIG. 1 is a side view of an exemplary delivery apparatus for a cardiovascular prosthetic device.

[0035] FIG. 2 is a side view of an exemplary introducer device assembly.

[0036] FIG. 3 is a side view of an expandable sheath that can be used in combination with the introducer device assembly of FIG. 2.

[0037] FIG. 4 is a side cross-sectional view of a portion of the expandable sheath of FIG. 3.

[0038] FIG. 5 is a magnified side view of a portion of the expandable sheath of FIG. 3.

[0039] FIG. 6A is a magnified side view of a portion of the expandable sheath of FIG. 3 with the outer layer removed for purposes of illustration.

[0040] FIG. 6B is a magnified side view of a portion of the braided layer of the expandable sheath of FIG. 3.

[0041] FIG. 7 is a magnified side view of a portion of the expandable sheath of FIG. 3 illustrating expansion of the sheath as a prosthetic device is advanced through the sheath.

[0042] FIGS. 8A-8B are cross-sectional views of an example expandable sheath moving from an unexpanded configuration to an expanded configuration. FIG. 8A shows the example expandable sheath in the unexpanded configuration. FIG. 8B shows the example sheath in the expanded configuration.

[0043] FIGS. 9A-9B are cross-sectional views of the exemplary liner of the example expandable sheath of FIGS. 8A-8B. FIG. 9A shows the exemplary liner in the unexpanded configuration. FIG. 9B shows the exemplary liner in the expanded configuration.

[0044] FIG. 10 is a perspective view of an exemplary liner of the example expandable sheath of FIGS. 8A-8B.

[0045] FIG. 11 is a side view of an exemplary expandable sheath and sheath hub assembly.

[0046] FIG. 12 is a cross-sectional view of an exemplary inner liner.

[0047] FIGS. 13A-13C are various views of an exemplary inner liner of an example expandable sheath. FIG. 13A shows a top view of an exemplary liner in the unexpanded configuration having varying first rest diameters (dr) along the central axis. FIG. 13B shows a side view of the exemplary liner of FIG. 13 A rotated 90° about the central axis of the expandable sheath / inner liner. FIG. 13C shows a bottom view of the exemplary liner of FIG. 13 A rotated 180° about the central axis of the expandable sheath / inner liner.

[0048] FIGS. 14A-14B are various views of an exemplary expandable sheath. FIG. 14A is a top view of the example expandable sheath. FIG. 14B is a cross-sectional side view of the exemplary expandable sheath taken along section line A-A of FIG. 14A.

[0049] FIGS. 15A-15C are various views of the exemplary expandable sheath of FIGS. 14A- 14B coupled to a sheath hub assembly. FIG. 15A is a side view of the expandable sheath and sheath hub assembly. FIG. 15B is a bottom view of the exemplary expandable sheath and sheath hub assembly. FIG. I5C is a cross-sectional side view of the exemplary expandable sheath and sheath hub assembly taken along section line B-B of FIG. 15B.

[0050] FIGS. 16A-16C are various plan views of an exemplary sheet for forming an inner liner of an example expandable sheath. FIG. 16A is a plan view of the exemplary sheet. FIG. 16B is a detail view of the exemplary sheet of FIG. 16A. FIG. 16C is another detail view of the exemplary sheet of FIG. 16A.

[0051] FIGS. 17A-17C are various views of an exemplary mandrel used for cutting an example sheet of an inner liner of an expandable sheath. FIG. 17 A is a top view of the exemplary mandrel. FIG. 17B is a bottom view of the exemplary mandrel rotated 180° relative to the view shown in FIG. 17A. FIG. 17C is a side view of the exemplary mandrel rotated a further 90° relative to the view shown in FIG. 17B.

[0052] In the drawings, like reference numbers and designations in the various drawings indicate like elements.DETAILED DESCRIPTION

[0053] The following description of examples of the inventive concepts should not be used to limit the scope of the claims. Other examples, features, aspects, implementations, and advantages will become apparent to those skilled in the art from the following description. As will be realized, the device and / or methods are capable of other different and obvious aspects, all without departing from the spirit of the inventive concepts. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

[0054] For purposes of this description, several aspects, advantages, and novel features of this disclosure are described herein. The described methods, systems, and apparatus should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the disclosure, alone and in various combinations and sub-combinations with one another. The disclosed methods, systems, and apparatus are not limited to any specific aspect, feature, or combination thereof, nor do thedisclosed methods, systems, and apparatus require that any one or more specific advantages be present or problems be solved.

[0055] Features, integers, characteristics, compounds, chemical moieties, or groups described in conjunction with a particular aspect or example of the present disclosure are to be understood to be applicable to any other aspect or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The present disclosure is not restricted to the details of any foregoing aspects. The present disclosure extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0056] It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

[0057] As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another aspect includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0058] "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0059] The terms “proximal'’ and “distal” as used herein refer to regions of a sheath, catheter, or delivery assembly. “Proximal” means that region closest to user of the device when the device is in use, while “distal” means that region farthest away from the user of the device and toward the implantation site.

[0060] “Axially” or “axial” as used herein refers to a direction along the central axis of the sheath.

[0061] Throughout the description and claims of this specification, the word “comprise” and variations of the word, such as “includes,” “comprising” and “comprises,” means “including but not limited to,” and is not intended to exclude, for example, other additives, components, integers or steps. “Exemplary” means “serving as an example, instance, or illustration” and is not intended to convey an indication of a preferred or ideal aspect. Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. As used herein, “e.g.” means “for example”. “Such as” is not used in a restrictive sense, but for explanatory purposes. Further, the term “coupled” generally means physically, mechanically, chemically, magnetically, and / or electrically coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language. It is further noted that the claims can be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.

[0062] Reference throughout this specification to “an implementation” means that a particular feature, structure, or characteristic described in connection with the implementation is included in at least one implementation. Thus, appearances of the phrases “in an implementation” in various places throughout this specification are not necessarily all referring to the same implementation or a single exclusive implementation. Furthermore, the particular features, structures, or characteristics described herein may be combined in any suitable manner in one or more implementations.

[0063] It will be understood that the benefits and advantages described herein can relate to one implementation or can relate to several implementations. Aspects described in connection with one implementation are intended to be able to be used with the other implementation. Any explanation in connection with one implementation applies to similar features of the other implementations, and elements of multiple implementations can be combined to formother implementations. The implementations are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages.

[0064] The expandable introducer sheaths and related componentry described herein can be used to deliver a prosthetic device through a subject’s (e.g., a living subject, a simulation, etc.) vasculature to a procedure site within the body. The sheath can be constructed to be highly expandable and radially collapsible. Disclosed aspects of the expandable sheath can minimize trauma to the vessel by reducing push forces required to advance the sheath through the blood vessel, and / or reducing push forces required to advance a medical device and / or delivery system through the sheath. In some examples, the expandable sheath can minimize trauma to the vessel by allowing for temporary expansion of a portion of the introducer sheath to accommodate a delivery system, followed by a return to an original diameter once the device passes therethrough.

[0065] Example expandable introducer sheaths are disclosed, for example, in U.S. Patent No. 8,690,936, entitled “Expandable Sheath for Introducing an Endovascular Delivery Device into a Body,” U.S. Patent No. 8,790,387, entitled “Expandable Sheath for Introducing an Endovascular Delivery Device into a Body,” U.S. Patent No. 10,639,152, entitled “Expandable Sheath and Methods of Using the Same,” U.S. Patent No. 10,792,471, entitled “Expandable Sheath,” U.S. Patent No. Application No. 16 / 407,057, entitled “Expandable Sheath with Elastomeric Cross Sectional Portions,” U.S. Patent No. 10,327,896, entitled “Expandable Sheath with Elastomeric Cross Sectional Portions,” U.S. Patent No. 11,273,062, entitled “Expandable Sheath,” Application No. PCT / US2021 / 019514, entitled “Expandable sheath for introducing an endovascular delivery device in to a body,” Application No. PCT / US2021 / 031227, entitled “Expandable sheath for introducing an endovascular delivery device into a body,” Application No. PCT / US2021 / 031275, entitled “Expandable sheath for introducing an endovascular delivery device into a body,”, Application No.PCT / US2022 / 032906, entitled “Expandable sheath for introducing an endovascular delivery device into a body,” Application No. PCT / US2022 / 032903, entitled “Expandable sheath for introducing an endovascular delivery device into a body,” U.S. Application No. 17 / 113,268, entitled “Expandable Sheath and Method of Using the Same,” Application No. PCT / US2021 / 058247, entitled “Self-Expanding, Two Component Sheath,” Application No. PCT / US2022 / 012785, entitled “Expandable Sheath,” U.S. Patent No. 11,051,939, entitled “Active Introducer Sheath System,” Application No. PCT / US2022 / 012684, entitled “Introducer with Sheath Tip Expander,” U.S. Application No. 17 / 078,556, entitled “Advanced Sheath Patterns,” Application No. PCT / US2021 / 025038, entitled “Lowtemperature hydrophilic adhesive for use in expandable sheath for introducing an endovascular delivery device into a body,” Application No. PCT / US2021 / 050006, entitled “Expandable Sheath Including Reversable Bayonet Locking Hub,” U.S. Provisional Application No. 63 / 280,251, entitled “Expandable Sheath Gasket to Provide Hemostasis,” U.S. Provisional Application No. 63 / 530,144, entitled “Introducer / Dilator with Folded Balloon,” U.S. Provisional Application No. 63 / 502,907, entitled “Lead Screw Driven Sheath Dilator,” and U.S. Provisional Application No. 63 / 663,256, entitled “Hybrid Proximal Caps Design for Scroll Access Sheath,” the disclosures of which are herein incorporated by reference.

[0066] Fig. 1 illustrates an exemplary sheath 100 in use with a representative delivery apparatus 10, such as a prosthetic heart valve or other prosthetic implant, to a subject. The delivery apparatus 10 illustrated can generally include a steerable guide catheter 14 and a balloon catheter 16 extending through the guide catheter 14. A prosthetic device, such as a prosthetic heart valve (prosthetic device 12), can be positioned on the distal end of the balloon catheter 16. The guide catheter 14 and the balloon catheter 16 can be adapted to slide longitudinally relative to each other to facilitate delivery and positioning of a prosthetic heart valve (prosthetic device 12) at an implantation site in a subject’s body.

[0067] As described in more detail herein, the sheath 100 comprises an elongate expandable tube that is inserted into a vessel (for example, transfemoral vessel, femoral artery, iliac artery) by passing through the skin of subject, such that the distal end of the sheath 100 is inserted into the vessel. The sheath 100 includes a hemostasis valve and / or sealing features at the proximal end of the sheath 100, for example, in the sheath hub 24, that provide hemostasis and prevents blood leakage from the subject through the sheath 100. The sheath 100, including an introducer 40, is advanced into the subject’s vasculature. Once positioned the introducer 40 is removed and the guide catheter 14 is inserted into / through the sheath 100, and the prosthetic heart valve (prosthetic device 12) then be delivered and implanted within subject. The guide catheter 14 includes a handle portion 18 and an elongated guide tube or shaft extending from the handle portion 18.

[0068] The prosthetic heart valve (prosthetic device 12) can be delivered into a subject’s body in a radially compressed configuration and radially expanded to a radially expanded configuration at the desired deployment site. In the illustrated example, the prosthetic heart valve (prosthetic device 12) is a plastically expandable prosthetic valve that is delivered into the subject’s body in a radially compressed configuration on a balloon of the balloon catheter 16 (as shown in FIG. 1) and then radially expanded to a radially expanded configuration atthe deployment site by inflating the balloon (or by actuating another type of expansion device of the delivery apparatus 10). Further details regarding a balloon-expandable expandable heart valve that can be implanted using the devices disclosed herein are disclosed in U.S.Patent No. 5,411,552, and also in U.S. Patent No. 9,393,110, both of which are incorporated herein by reference. Further details regarding a plastically expandable heart valve that can be implanted using the devices disclosed herein are disclosed in U.S. Publication No. 2012 / 0123529, which is incorporated herein by reference.

[0069] The expandable introducer sheaths disclosed herein may also be used to deliver other types of implantable medical device, such as self-expanding and mechanically expanding implantable heart valves, stents or filters. For example, the prosthetic heart valve (prosthetic device 12) can be a self-expandable heart valve that is restrained in a radially compressed configuration by a sheath (for example, sheath 100) or other component of the delivery apparatus 10 and self-expands to a radially expanded configuration when released by the sheath or other component of the delivery apparatus 10. Further details regarding a selfexpandable heart valve that can be implanted using the devices disclosed herein are disclosed in U.S. Publication No. 2012 / 0239142, which is incorporated herein by reference.

[0070] In still some examples, the prosthetic heart valve (prosthetic device 12) can be a mechanically expandable heart valve that comprises a plurality of struts connected by hinges or pivot joints and is expandable from a radially compressed configuration to a radially expanded configuration by actuating an expansion mechanism that applies an expansion force to the prosthetic valve. Further details regarding a mechanically expandable heart valve that can be implanted using the devices disclosed herein are disclosed in U.S. Publication No. 2018 / 0153689, which is incorporated herein by reference.

[0071] In still some examples, a prosthetic valve can incorporate two or more of the abovedescribed technologies. For example, a self-expandable heart valve can be used in combination with an expansion device to assist expansion of the prosthetic heart valve.

[0072] Beyond transcatheter heart valves, the introducer sheath system can be useful for other types of minimally invasive surgery, such as any surgery requiring introduction of an apparatus into a subject’s vessel. For example, the introducer sheath system can be used to introduce other types of delivery apparatuses for placing various types of intraluminal devices (for example, stents, stented grafts, balloon catheters for angioplasty procedures, etc.) into many types of vascular and non-vascular body lumens (for example, veins, arteries, esophagus, ducts of the biliary tree, intestine, urethra, fallopian tube, other endocrine or exocrine ducts, etc.). The term “implantable” as used herein is broadly defined to meananything - prosthetic or not - that is delivered to a site within a body. A diagnostic device, for example, may be an implantable.

[0073] FIG. 2 illustrates an example of an introducer device assembly 20. The introducer device assembly 20 may include the sheath 100 and an introducer 40. The introducer 40 may be positioned within a central lumen 120 (indicated in FIG. 4) of the sheath 100, as shown in FIG. 2. An optional control housing 22 may be positioned at a proximal end of the assembly and may include a sheath hub 24 and an introducer hub 30. The sheath hub 24 and introducer hub 30 may optionally couple together, as shown in FIG. 2.

[0074] The sheath 100 and introducer 40 are shown in an insertion configuration, for insertion together into the subject’s vasculature. Upon insertion into the subject’s vasculature, the introducer 40 may be withdrawn longitudinally from the sheath 100, leaving the sheath 100 within the subject’s vasculature. Features of the sheath 100 and the introducer 40 individually are discussed below, as well as the operation of the sheath 100 and introducer 40 together.

[0075] The sheath 100 comprises an elongated body that may have a cylindrical shape. The sheath 100 has a distal end 104 and a proximal end 102, and a length LI (see FIG. 3) extending from the distal end 104 to the proximal end 102. The sheath 100 is configured to be inserted into a subject’s vasculature. The sheath 100 may optionally comprise an introducer sheath that is used to introduce a delivery apparatus 10 into the subject’s vasculature.

[0076] The vasculature may comprise the blood vessels of the subject’s body which may include the femoral artery or other vessels of the subject’s body. The vasculature, such as the femoral artery, may be narrow or stiff, and may be difficult to easily insert a delivery apparatus therein. For example, the delivery apparatus may be larger than the vasculature, or may be unwieldy to penetrate through the skin or vasculature of the subject to pass therethrough by itself. Also, the vasculature may be too fragile to receive the delivery apparatus without use of an introducer sheath.

[0077] The sheath 100 accordingly may optionally be inserted into the subject’s vasculature prior to the delivery apparatus 10 being introduced, to provide an entry way or guide path for the delivery apparatus 10 to introduce the delivery apparatus 10 into the subject’s vasculature. After the sheath 100 is inserted, the sheath 100 may remain positioned within and surrounded by the subject’s vasculature. The delivery apparatus 10 may then be passed through the lumen of the sheath 100 for introduction into the subject’s body. The sheath 100 may remain in the vasculature until a desired time to remove the sheath 100.

[0078] The sheath 100 may be inserted into the vasculature percutaneously or a portion of the subject’s body may be surgically opened for the sheath 100 to access the vasculature. The delivery apparatus 10 passes through the lumen of the sheath 100 to reach a desired position in the subject’s body. As shown in FIG. 1, the delivery apparatus 10 may pass through an opening at the proximal end of the sheath 100 for passage through the central lumen 120 of the sheath 100 and the vasculature of the subject. For example, in some examples, the delivery apparatus 10 passes through an opening at the proximal end of the sheath 100 provided at the control housing 22 shown in FIG. 2.

[0079] In some examples, delivery apparatus 10 and the assemblies disclosed herein may be used in transcatheter aortic valve implantation (TAVI) and / or delivery and / or implantation of any other valve (e.g., mitral, tricuspid, pulmonic). The delivery apparatus 10 and the systems disclosed herein may be utilized for transarterial access, including transfemoral access, to a subject’s heart.

[0080] The sheath 100 may optionally include a strain relief portion at the proximal end 102 of the sheath 100. The strain relief portion may be sized larger than a proximate portion of the sheath 100 and may seal the entry point of the vasculature, to reduce the possibility of blood or other fluid being released between the exterior surface of the sheath 100 and the vasculature. The strain relief portion provides a transition between the larger diameter proximal opening of the sheath 100 and the smaller diameter distal portion / opening of the sheath 100 as the medical device and / or introducer 40 are inserted into the central lumen 120 of the sheath 100. In some examples, a seal 48 is optionally positioned along the length of the sheath 100 to further prevent blood or other fluid flow from passing around the sheath 100 toward and out of the proximal end 102 of the sheath 100.

[0081] FIG. 3 illustrates a side view of an exemplary expandable sheath 100 that can be used in the introducer device assembly of FIG. 2. As shown in FIG. 3, the sheath hub 24 is optionally positioned at the proximal end 102 of the sheath 100. The sheath hub 24 may optionally include an internal chamber for the delivery apparatus 10 to be passed through to be delivered to the subject's vasculature. The sheath hub 24 may be configured to remain external to the subject’s vasculature when the sheath 100 is inserted therein and may be configured to remain external to the subject’s skin for a percutaneous implantation of the sheath 100. The sheath hub 24 may be configured for a user (such as a surgeon) to grip to manipulate the sheath 100.

[0082] The sheath hub 24 may optionally comprise a cylindrical body and may include a coupling feature for coupling the sheath hub 24 to another housing or component of thesystem. The sheath hub 24 may optionally include a fluid port 26 for passing fluid such as blood to or from the subject’s vasculature. Tubing 27 with a valve 28 may be coupled to the fluid port 26, for passing fluid through the fluid port 26 and for sealing flow of the fluid through the fluid port 26.

[0083] In some examples, the introducer sheath 100 need not include a sheath hub 24. For example, the sheath 100 can be an integral part of a component of the delivery apparatus 10, such as the guide catheter 14. For example, the sheath 100 can extend from the handle portion 18 of the guide catheter 14. Additional examples of introducer devices and expandable sheaths can be found in U.S. Patent No. 11,273,062, which is incorporated by reference in its entirety.

[0084] FIGS. 4 and 5 illustrate a cross-sectional view and a side view, respectively, of a portion of the expandable sheath 100. As shown in FIG. 5, the sheath 100 can have a natural, unexpanded outer diameter DI. In some examples, the expandable sheath 100 optionally includes a plurality of co-axial layers extending along at least a portion of the length LI of the sheath (FIG. 3). For example, with reference to FIG. 4, the expandable sheath 100 can include a first layer / inner layer 52 (also referred to as an inner liner), a second layer / braided layer 54 disposed around and radially outward of the inner layer 52, a third layer / elastic layer 56 disposed around and radially outward of the braided layer 54, and a fourth layer / outer layer 58 (also referred to as an outer layer) disposed around and radially outward of the elastic layer 56. In the illustrated configuration, the inner layer 52 can define the central lumen 120 extending along a longitudinal central axis 122. In some examples, the sheath 100 may optionally include the inner layer 52 without the outer layer 58, or the outer layer 58 without the inner layer 52, depending upon the particular characteristics desired.

[0085] Referring to FIG. 5, when the sheath 100 is in an unexpanded state, the inner layer 52 and / or the outer layer 58 can form longitudinally-extending folds or creases such that the surface of the sheath comprises a plurality of ridges 62 (also referred to herein as “folds”). The ridges 62 can be circumferentially spaced apart from each other by longitudinally- extending valleys 64. When the sheath expands beyond its natural diameter DI, the ridges 62 and the valleys 64 can level out or be taken up as the surface radially expands and the circumference increases, as further described below. When the sheath collapses back to its natural diameter, the ridges 62 and valleys 64 can reform.

[0086] In some examples, the inner layer 52 and / or the outer layer 58 can comprise a relatively thin layer of polymeric material. For instance, in some examples, the thickness of the inner layer 52 can be from 0.01 mm to 0.5 mm, 0.02 mm to 0.4 mm, or 0.03 mm to 0.25mm. In some examples, the thickness of the outer layer 58 can be from 0.01 mm to 0.5 mm, 0.02 mm to 0.4 mm, or 0.03 mm to 0.25 mm.

[0087] In some examples, the inner layer 52 and / or the outer layer 58 can comprise a lubricious, low-friction, and / or relatively non-elastic material. In some examples, the inner layer 52 and / or the outer layer 58 can comprise a polymeric material having a modulus of elasticity of 400 MPa or greater. Exemplary materials can include ultra-high-molecular- weight polyethylene (UHMWPE) (for example, Dyneema®), high-molecular-weight polyethylene (HMWPE), or polyether ether ketone (PEEK). With regard to the inner layer 52 in particular, such a low coefficient of friction materials can facilitate passage of the prosthetic device 12 through the central lumen 120. Other suitable materials for the inner and outer layers can include polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), ethylene tetrafluoroethylene (ETFE), nylon, polyethylene, polyether block amide (for example, Pebax), and / or combinations of any of the above. Some examples of a sheath 100 can include a lubricious liner on the inner surface of the inner layer 52. Examples of suitable lubricious liners include materials that can further reduce the coefficient of friction of the inner layer 52, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Suitable materials for a lubricious liner also include other materials desirably having a coefficient of friction of 0.1 or less.

[0088] Additionally, some examples of the sheath 100 can include an optional exterior hydrophilic coating on the outer surface of the outer layer 58. Such a hydrophilic coating can facilitate insertion of the sheath 100 into a subject’s vessel, reducing potential damage. Examples of suitable hydrophilic coatings include the Harmony™ Advanced Lubricity Coatings and other Advanced Hydrophilic Coatings available from SurModics, Inc., Eden Prairie, MN. DSM medical coatings (available from Koninklijke DSM N.V., Heerlen, the Netherlands), as well as other hydrophilic coatings (for example, PTFE, polyethylene, polyvinylidene fluoride), are also suitable for use with the sheath 100. Such hydrophilic coatings may also be optionally included on the inner surface of the inner layer 52 to reduce friction between the sheath 100 and the delivery apparatus 10, thereby facilitating the use and improving safety. In some examples, a hydrophobic coating, such as Perylene, may be used on the outer surface of the outer layer 58 or the inner surface of the inner layer 52 in order to reduce friction.

[0089] In some examples, the second layer / braided layer 54 can include a braided material. FIGS. 6 A and 6B illustrate the sheath 100 with the outer layer 58 removed to expose the elastic layer 56. With reference to FIGS. 6A and 6B, the braided layer 54 can comprise aplurality of members or filaments 60 (for example, metallic or synthetic wires or fibers) braided together. The braided layer 54 can have any desired number of filaments 60, which can be oriented and braided together along any suitable number of axes. For example, with reference to FIG. 6B, the filaments 60 can include a first set of filaments 60A oriented parallel to a first axis A, and a second set of filaments 60B oriented parallel to a second axis B. The filaments 60 A and 60B can be braided together in a biaxial braid such that filaments 60 A oriented along axis A form an angle 0 with the filaments 60B oriented along axis B. In some examples, the angle 0 can be from 5° to 70°, 10° to 60°, 10° to 50°, or 10° to 45°. In the illustrated example, the angle 0 is 45°. In some examples, the filaments 60 can also be oriented along three axes and braided in a triaxial braid, or oriented along any number of axes and braided in any suitable braid pattern.

[0090] The braided layer 54 can extend along substantially the entire length LI of the sheath 100, or alternatively, can extend only along a portion of the length of the sheath 100. In some examples, the filaments 60 can be wires made from metal (for example, Nitinol, stainless steel, etc.), or any of various polymers or polymer composite materials, such as carbon fiber. In some examples, the filaments 60 can be round, and can have a diameter of from 0.01 mm to 0.5 mm, 0.03 mm to 0.4 mm, or 0.05 mm to 0.25 mm. In some examples, the filaments 60 can have a flat cross-section with dimensions of 0.01 mm x 0.01 mm to 0.5 mm x 0.5 mm, or 0.05 mm x 0.05 mm to 0.25 mm x 0.25 mm. In one example, filaments 60 having a flat crosssection can have dimensions of 0. 1 mm x 0.2 mm. However, other geometries and sizes are also suitable for some examples. If a braided wire is used, the braid density can be varied. Some examples have a braid density of from ten picks per inch to eighty picks per inch, and can include eight wires, sixteen wires, or up to fifty-two wires in various braid patterns. In some examples, the braided layer 54 can be laser cut from a tube, or laser-cut, stamped, punched, etc., from sheet stock and rolled into a tubular configuration. The braided layer 54 can also be woven or knitted, as desired.

[0091] The third layer / elastic layer 56 can be a resilient, elastic layer (also referred to as an elastic material layer). In some examples, the elastic layer 56 can be configured to apply force to the underlying inner layer 52 and braided layer 54 in a radial direction (for example, toward the central axis 122 of the sheath 100) when the sheath 100 expands beyond its natural diameter by passage of the delivery apparatus 10 through the sheath 100. Stated differently, the elastic layer 56 can be configured to apply encircling pressure to the layers of the sheath 100 beneath the elastic layer 56 to counteract expansion of the sheath 100. Theradially inwardly directed force is sufficient to cause the sheath 100 to collapse radially back to its unexpanded state after the delivery apparatus 10 is passed through the sheath 100.

[0092] In the illustrated example, the elastic layer 56 can optionally include one or more members configured as strands, ribbons, or bands 66 helically wrapped around the braided layer 54. For example, in the illustrated sheath 100, the elastic layer 56 comprises two elastic bands 66A and 66B wrapped around the braided layer with opposite helicity, although the elastic layer may comprise any number of bands depending upon the desired characteristics. The elastic bands 66A and 66B can be made from, for example, any of a variety of natural or synthetic elastomers, including silicone rubber, natural rubber, any of various thermoplastic elastomers, polyurethanes such as polyurethane siloxane copolymers, urethane, plasticized polyvinyl chloride (PVC), styrenic block copolymers, polyolefin elastomers, etc.

[0093] In some examples, the elastic layer 56 can comprise an elastomeric material having a modulus of elasticity of 200 MPa or less. In some examples, the elastic layer 56 can comprise a material exhibiting an elongation to break of 200% or greater, or an elongation to break of 400% or greater. The elastic layer 56 can also take other forms, such as a tubular layer comprising an elastomeric material, a mesh, a shrinkable polymer layer such as a heat-shrink tubing layer, etc. In lieu of, or in addition to, the elastic layer 56, the sheath 100 may also include an optional elastomeric or heat-shrink tubing layer around the outer layer 58. Examples of such elastomeric layers are disclosed in U.S. Patent Nos. 9,301,841, 10,792,471, and 10,856,981, which are incorporated herein by reference. In some examples, the elastic layer 56 can also be radially outward of the polymeric outer layer 58.

[0094] In some examples, one or both of the inner layer 52 and / or the outer layer 58 can be configured to resist axial shortening of the sheath 100 when the sheath expands radially. More particularly, one or both of the inner layer 52 and / or the outer layer 58 can resist stretching against longitudinal forces caused by friction between a prosthetic device 12 and the inner surface of the sheath such that the length remains substantially constant as the sheath 100 expands and contracts radially. The length can be measured along all or a portion of the sheath 100. For example, in some implementations, the length is measured along the portion of the sheath 100 subject to radial expansion. Alternatively, the length can be measured along an entire length of the sheath 100. In some examples, as shown in FIG. 1, the length can be measured between the distal end 104 of the sheath 100 and the proximal end 102 of the sheath at the sheath hub 24. In some examples, the length can be LI. As used herein with reference to the length of the sheath 100, the term “substantially constant” means that a length of the sheath 100 (e.g. any of the aforementioned lengths) increases by not morethan 1%, by not more than 5%, by not more than 10%, by not more than 15%, or by not more than 20%. Meanwhile, with reference to FIG. 6B, the filaments 60 A and 60B of the braided layer can be allowed to move angularly relative to each other such that the angle 0 changes as the sheath 100 expands and contracts. This, in combination with the longitudinal ridges 62 (folds) in the inner layer 52 and / or outer layer 58, can allow the central lumen 120 to expand as a prosthetic device 12 is advanced through it.

[0095] In some examples, the inner layer 52 and the outer layer 58 can be heat-bonded during the manufacturing process such that the braided layer 54 and the elastic layer 56 are encapsulated between the inner layer 52 and the outer layer 58. More specifically, in some examples, the inner layer 52 and the outer layer 58 can be adhered to each other through the spaces between the filaments 60 of the braided layer 54 and / or the spaces between the elastic bands 66. The inner layer 52 and outer layer 58 can also be bonded or adhered together at the proximal and / or distal ends of the sheath. In some examples, the inner layer 52 and outer layer 58 are not adhered to the filaments 60. This can allow the filaments 60 to move angularly relative to each other, and relative to the inner layer 52 and outer layer 58, allowing the diameter of the braided layer 54, and thereby the diameter of the sheath, to increase or decrease. As the angle 0 between the filaments 60A and 60B changes, the length of the braided layer 54 can also change. For example, as the angle 0 increases, the braided layer 54 can foreshorten, and as the angle 0 decreases, the braided layer 54 can lengthen to the extent permitted by the areas where the inner layer 52 and outer layer 58 are bonded. However, because the braided layer 54 is not adhered to the inner layer 52 and outer layer 58, the change in length of the braided layer that accompanies a change in the angle 0 between the filaments 60A and 60B does not result in a significant change in the length LI of the sheath 100.

[0096] FIG. 7 illustrates radial expansion of the sheath 100 as a prosthetic heart valve 12 is passed through the sheath 100 in the direction of arrow A (for example, distally). As the prosthetic heart valve 12 is advanced through the sheath 100, the sheath 100 can resiliently expand to a second diameter D2 that corresponds to a size or diameter of the prosthetic device 12. As the prosthetic heart valve 12 is advanced through the sheath 100, the prosthetic device 12 can apply longitudinal force to the sheath 100 in the direction of motion by virtue of the frictional contact between the prosthetic device 12 and the inner surface of the sheath 100. However, as noted above, the inner layer 52 and / or the outer layer 58 can be optionally configured to resist axial elongation such that the length LI of the sheath 100 remainsconstant, or substantially constant. This can reduce or prevent the braided layer 54 from lengthening, and thereby constricting the central lumen 120.

[0097] Meanwhile, in some examples, the angle 0 between the filaments 60A and 60B can increase as the sheath 100 expands to the second diameter D2 to accommodate the prosthetic device 12. This can cause the braided layer 54 to foreshorten. However, because the filaments 60 are not engaged or adhered to the inner layer 52 or outer layer 58, the shortening of the braided layer 54 attendant to an increase in the angle 0 does not affect the overall length LI of the sheath 100. Moreover, because of the longitudinally-extending ridges 62 (folds) formed in the inner layer 52 and outer layer 58, the inner layer 52 and outer layer 58 can expand to the second diameter D2 without rupturing, in spite of being relatively thin and relatively non-elastic. In this manner, the sheath 100 can resiliently expand from its natural diameter DI to a second diameter D2 that is larger than the diameter DI as a prosthetic device 12 is advanced through the sheath 100, without lengthening, and without constricting. Thus, the force required to push the prosthetic device 12 through the sheath 100 is significantly reduced.

[0098] Additionally, because of the radial force applied by the elastic layer 56, the radial expansion of the sheath 100 can be localized to the specific portion of the sheath 100 occupied by the prosthetic device 12. For example, with reference to FIG. 7, as the prosthetic heart valve 12 moves distally through the sheath 100, the portion of the sheath 100 immediately proximal to the prosthetic heart valve 12 can radially collapse back to the initial diameter DI under the influence of the elastic layer 56. The inner layer 52 and outer layer 58 can also buckle as the circumference of the sheath 100 is reduced, causing the ridges 62 and the valleys 64 to reform. This can reduce the size of the sheath 100 required to introduce a prosthetic device 12 of a given size. Additionally, the temporary, localized nature of the expansion can reduce trauma to the blood vessel into which the sheath 100 is inserted, along with the surrounding tissue, because only the portion of the sheath 100 occupied by the prosthetic device 12 expands beyond the sheath’s natural diameter and the sheath 100 collapses back to the initial diameter once the prosthetic device 12 has passed. This limits the amount of tissue stretched in order to introduce the prosthetic device 12, and the amount of time for which a given portion of the vessel is dilated to allow the prosthetic device 12 to pass.

[0099] In addition to the advantages above, the expandable sheath 100 examples described herein can provide surprisingly superior performance relative to known introducer sheaths. For example, it is possible to use a sheath 100 configured as described herein to deliver aprosthetic device 12 having a diameter that is two times larger, 2.5 times larger, or even three times larger (e.g., between 1.5-2.5 times larger, at least 1.5 times larger, between 2-3.5 times larger, at least 2 times larger, and / or at least 2.5 times larger) than the natural outer diameter of the sheath 100. For instance, in one example, a crimped prosthetic heart valve having a diameter of 7.2 mm was successfully advanced through a sheath 100 configured as described above and having a natural outer diameter of 3.7 mm. As the prosthetic valve was advanced through the sheath 100, the outer diameter of the portion of the sheath 100 occupied by the prosthetic valve increased to 8 mm. In other words, it was possible to advance a prosthetic device having a diameter more than two times the outer diameter of the sheath 100 through the sheath 100, during which the outer diameter of the sheath 100 resiliency increased by 216%. In some examples, a sheath 100 with an initial or natural outer diameter of 4.5 mm to 5.0 mm can be configured to expand to an outer diameter of 8 mm to 9 mm.

[0100] In some examples, a sheath 100 can be configured to expand such that its outer diameter expands to at least 150%, at least 155%, at least 160%, at least 165%, at least 170%, at least 175%, at least 180%, at least 185%, at least 190%, at least 195%, and / or at least 200% of its initial outer diameter. In some examples, a sheath 100 can be configured to expand such that its inner diameter expands to at least 150%, at least 155%, at least 160%, at least 165%, at least 170%, at least 175%, at least 180%, at least 185%, at least 190%, at least 195%, and / or at least 200% of its initial inner diameter.

[0101] FIGS. 8A and 8B provide cross-sectional views of an example of the (layered) structure of the example sheath 100 of FIG. 1 including a rolled inner liner 106 in the unexpanded and expanded configurations. As shown in FIGS. 8A and 8B, in some examples, the rolled inner liner 106 is located radially inward of the inner layer 52 such that the inner liner 106 forms the central lumen 120 of the sheath 100. FIGS. 9A and 9B show end views of the example inner liner 106 in the unexpanded and expanded configurations. FIG. 10 is a perspective view of an example inner liner 106 usable and / or for use with the disclosed sheath 100. As illustrated in FIGS. 8 A- 10, the example sheath 100 comprises an inner liner 106 wound into a spiral configuration. Additional examples of expandable sheaths including a rolled or coiled inner liner 106 can be found in PCT / US2021 / 019514,PCT / US 2022 / 032906, and PCT / US2022 / 032903, each of which are incorporated by reference in their entirety. As used herein, the inner liner 106 can include any of the attributes of the inner layer 52 described herein in reference to FIGS. 4-6 A, including any of the various layered sheath structures. However, it is also contemplated that the inner liner 106can be formed from a sheet 108 that is wound into the spiral configuration that defines the central lumen 120 of the sheath 100.

[0102] As described herein, the sheath 100 is configured to locally expand from an unexpanded configuration in which the central lumen 120 has a first diameter to an expanded configuration in which the central lumen 120 has a second, larger, diameter. For example, the sheath 100 will expand due to an outwardly directed radial force exerted on the central lumen 120 of the sheath 100 by a medical device passing through the sheath 100. The sheath 100 is configured to then locally contract at least partially back to the unexpanded configuration as the medical device passes therethrough. Similarly, the inner liner 106 can be configured to move between an unexpanded configuration (shown in FIGS. 8 A and 9 A) and an expanded configuration (shown in FIGS. 8B and 9B), in response to an outwardly directed radial force on the central lumen 120 of the sheath 100. It is contemplated that movement of the inner liner 106 between the unexpanded and expanded configurations results in a corresponding movement of the other layer and / or various other layers of the sheath 100 between the unexpanded and expanded configurations.

[0103] In some examples, sheath 100 is configured to expand as a medical device (e.g., prosthetic device 12 and / or delivery apparatus 10) passes therethrough, and then to contract at least partially back (e.g., at least 80%, at least 85%, at least 90%, at least 95% back, at least 98% back) to an initial unexpanded configuration after the medical device passes therethrough.

[0104] As illustrated in FIGS. 8A-10, the inner liner 106 is rolled or coiled such that at least a portion of the inner surface 114 of the sheet 108 forming the inner liner 106 overlays at least a portion of the outer surface 116 of the sheet 108, forming an overlapping portion 118. When wound into the spiral configuration, the inner surface 114 of the sheet 108 defines the central lumen 120 of the sheath 100 such that the central lumen 120 extends along the central axis 122 of the sheath 100.

[0105] The inner liner 106 is configured such that a longitudinally-extending first edge 110 of the sheet 108 is slidable along at least a portion the inner surface 114 of the sheet 108, and a longitudinally-extending second edge 112 is slidable along at least a portion of the outer surface 116 of the sheet 108. Accordingly, as illustrated in FIGS. 9A and 9B, as the inner liner 106 (and thus the sheath 100) moves from the unexpanded configuration to the expanded configuration (for example, upon introduction of a medical device into the central lumen 120 of the sheath 100), the first edge 110 and the second edge 112 slide relative to each other and expand the inner liner 106 from a unexpanded first rest diameter (r / ,) to asecond expanded diameter (de), thereby shortening the overlapping portion 118 of the inner liner 106.

[0106] In some examples, in the unexpanded configuration, the first edge 1 10 and the second edge 112 of the sheet 108 are substantially aligned in a spaced relationship along a radial axis passing through a thickness of the sheath 100.

[0107] In some examples, in the unexpanded configuration, the inner liner 106 comprises at least two layers of the sheet 108 overlaying each other along at least a portion of a circumference of the sheath 100.

[0108] In some examples, when the sheath 100 / inner liner 106 is in the expanded configuration, the first edge 110 of the sheet 108 is substantially aligned with the radial axis passing through a thickness of the expandable sheath 100 and the second edge 112 circumferentially offset from the radial axis.

[0109] It is understood that the second expanded diameter (de) is configured to accommodate the medical device passing through the central lumen 120 of the sheath 100. As described herein, the sheath 100 contracts to / toward the unexpanded configuration / unexpanded first rest diameter (dr) after passage of the medical device through the central lumen 120 of the sheath 100.

[0110] In some examples, a lubricant and / or lubricious liner can be disposed between at least a portion of the overlapping portion 118 of the sheet 108 and at least a portion of the sliding portions of the sheet 108. In some examples, the polymer layer of the sheet 108 comprises a compound material comprising a polyolefin and a lubricious filler to increase lubricity / reduce friction between the overlapping portions 118 of the inner liner 106 and the inner liner 106 expands. For example, the lubricious filler can be present in an amount from about 5 wt % to about 20 wt % of a total weight of the compound material.

[0111] In some examples, the sheath 100 includes a tie layer. The tie layer can be coextruded with the sheet 108 material of the inner liner 106.

[0112] Similar to the layered sheath 100 structure described herein in reference to FIGS. 4-7, the layered sheath structure illustrated FIGS. 8A and 8B include the braided layer 54 and the polymeric / elastomeric outer layer 58. In some examples, as described herein, the sheath 100 includes an elastic layer 56 radially inward of the outer layer 58. In some examples, and as shown in FIG. 8A, the outer layer 58 can comprise the braided layer 54 that is not embedded in the layer of the elastomeric outer layer 58. While in the other examples, and as shown in FIG. 4, the outer layer 58 can comprise the braided layer 54 that is embedded in the layer of the elastomeric outer layer 58.

[0113] The inner liner 106 defines the central lumen 120 through which the delivery apparatus 10 can travel into a subject’s vessel in order to deliver, remove, repair, and / or replace a prosthetic device. In some examples, the sheet 108 used to make the inner liner 106 can comprise a high-density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof. In some examples, the sheet 108 can comprise one or more layers. In some examples, if one or more layers are present, each layer can comprise the same or different polymer. In some examples, the sheet 108 can have a predetermined thickness, wherein the predetermined thickness can be defined by one of ordinary skill in the art depending on the specific application. In some examples, the predetermined thickness of the inner liner can be from about 0.002 inches to about 0.025 inches, including exemplary values of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, about 0.01, about 0.015, and about 0.02 inches. It is further understood that the predetermined thickness of the sheet 108 forming the inner liner 106 can be varied depending on the desired amount of radial expansion, as well as the strength required.

[0114] In some examples, the inner surface 114 of the sheet 108 can be at least partially ribbed or textured. In yet further examples, the sheet 108 can also be lubricious. For example, the sheet 108 that forms the inner liner 106 can have a coefficient of friction less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, less than about 0.1, or less than about 0.05, or even less than about 0.01. It is further understood that the sheet 108 can have a coefficient of friction having any value between any two foregoing values. Such an inner liner 106 can facilitate passage of a delivery apparatus 10 through the central lumen 120 of the disclosed sheath 100. In some examples, materials that can be used to form suitable lubricious liner include materials that can reduce the coefficient of friction of the inner liner 106, such as PTFE, polyethylene, poly vinylidene fluoride, and combinations thereof. Suitable materials for a lubricious liner also include other materials desirably having a coefficient of friction of about 0. 1 or less, of about 0.09 or less, about 0.08 or less, about 0.07 or less, about 0.05 or less, about 0.04 or less, about 0.03 or less, about 0.02 or less, or about 0.01 or less.

[0115] In some examples, the outer layer comprising the braid or coil (braided layer 54) and the layer of the elastomeric polymer (elastomeric outer layer 58) can have any predetermined thickness. It is understood that the predetermined thickness of the outer layer can be dependent on the specific application of the sheath 100. For example, and without limitation, the thicknesses of the inner liner 106 and the outer layer comprising the braided layer 54 and the layer of the elastomeric outer layer 58 can also be varied depending on the particular application of the disclosed sheath. In some examples, the thickness of the inner liner 106ranges from about 0.0005 inches to about 0.010 inches, including exemplary values of about 0.0006, about 0.0007, about 0.0008, about 0.0009, about 0.001, about 0.002, about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009 inches, and in one particular example, the thickness can be about 0.002 inches. The outer layer comprising the braided layer 54 and the layer of the elastomeric outer layer 58 can have a thickness of from about 0.002 inches to about 0.015 inches, including exemplary values of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, and about 0.01 inches.

[0116] It is understood that the inner liner 106 can have any shape or configuration depending on the desired application and the size of the delivery apparatus 10 and prosthetic device 12. It is further understood that the inner liner 106 is not limited to a specific shape or configuration. In some examples, the outer layer comprising the braided layer 54 and the layer of the elastomeric outer layer 58 can conform to the shape or configuration of the inner liner 106.

[0117] FIG. 11 illustrates a side view of the sheath 100 described in each of the examples provided herein. As described here and shown in FIG. 11 (and FIGS. 2 and 3), the sheath 100 is coupled to a sheath hub 24 at its proximal end 102. The present disclosure provides for additional support layers and / or structure provided along the proximal end 102 of the sheath 100 to help reduce the likelihood of damage to the sheath 100 caused and / or frustrated by the coupling between the sheath 100 and the locking nut 25.

[0118] As illustrated in FIG. 11, the sheath 100 has a flared or tapered section 128 adjacent to the proximal end 102. As shown, the diameter of the flared / tapered section 128 increases from a tubular section 130 of the sheath 100 toward the proximal end 102 of the sheath 100. Likewise, in some examples, the inner diameter of the expandable sheath 100 has an increasing diameter along the flared / tapered section 128 from the tubular section 130 toward the proximal end 102 of the expandable sheath 100. In some examples, the flaring / tapering extends through a most proximal section 132 of the proximal end 102 of the sheath 100. In other examples, the proximal section 132 returns to a generally tubular configuration. In some examples, the flared / tapered section 128 provides a proximal end 102 of the sheath 100 that has a size and shape corresponding to the size and shape of the distal end of the sheath hub 24. As such, the proximal end 102 of the sheath 100 is received over the distal end of the sheath hub 24 and held in place by a compression fit with the locking nut 25.

[0119] In some implementations, the sheath 100 includes an outer jacket 123 that helps to ensure hemostasis and provides a smooth and lubricious surface in contact with the subjectanatomy along the majority of the length of the sheath 100. In some implementations, the outer jacket 123 is provided along the entire length of the sheath 100. In some implementations, the outer jacket 123 is not provided along the distal end 104 of the sheath 100. In some examples, the outer jacket 123 is radially outward of the inner layer 52 and the outer layer 58. In some implementations, the outer jacket 123 is composed of a flexible and / or elastic material such as Pebax or Neusoft.

[0120] As illustrated in FIG. 11, the sheath 100 includes a strain relief portion having a strain relief layer 129 for limiting radial expansion along a portion of the length of the sheath 100. For example, the strain relief layer 129 can be composed of a material having a higher durometer than the underlying layers of the sheath 100, including the inner layer 52 and / or outer layer 58. In some examples, the strain relief layer 129 is provided over the inner layer 52 and / or outer layer 58. In some implementations, the strain relief layer 129 is provided over the outer jacket 123. In some examples, strain relief layer 129 extends along at least a portion of the length of the sheath 100 and comprises a stiffer and / or less elastomeric material than the underlying layers of the sheath 100 (e.g., a stiffer material than the inner layer 52 and / or outer layer 58) such that the strain relief layer 129 restricts expansion of the underlying layers of the sheath 100. In some examples, the strain relief layer 129 is composed of multiple layers of material. The additional layer can have the same durometer or greater than the inner layer 52, outer layer 58, and / or outer jacket 123. In some examples, strain relief layer 129 can have a dual layer construction where the inner layer is composed of a flexible and / or elastic material such as Pebax, and the outer layer is constructed from a material such as Neusoft that provides enhanced lubricity to ease insertion and reduce friction with the subject’s blood vessel. In some examples, the dual / multiple layer structure of the strain relief layer 129 mimics the composition of a lubricious outer jacket 123 provided over the sheath 100.Additionally, the multiple layer structure of the strain relief layer 129 helps to resist expansion of the sheath 100 along the strain relief layer 129 while also maintaining thickness in the expanded region of the flared / tapered section 128 and proximal section 132.

[0121] In some examples, including the example illustrated in FIG. 11, the strain relief layer 129 includes the proximal section 132 adjacent the proximal end 102 of the sheath 100, the flared / tapered section 128 extending distally from the proximal section 132, and a tubular section (labeled 129) adjacent a distal end of the flared / tapered section 128.

[0122] FIG. 12 illustrates a cross-sectional view of an example inner liner 206 according to an additional configuration. The inner liner 206 can be used with a sheath similar to the sheath 100 described herein in reference to FIGS. 1-11. Likewise, the inner liner 206 issimilar to the inner liner 106 described in reference to FIGS. 1-11. Thus, similar reference numbers as those used for the example shown in FIGS. 1-11 are used to reference similar features of the example shown in FIG. 12. Furthermore, any features in any other example disclosed herein (for example, liner 106) can be included in the example liner 206. Similar to the liner 106 shown in FIGS. 1-11, the inner liner 206 can be used with a sheath including one or more of an inner layer 52, outer layer 58, braided layer 54, elastic layer 56, strain relief layer 129, and outer jacket 123, or combinations thereof.

[0123] In this example, the variable diameter inner liner 206 comprises a sheet 208 having a first longitudinal edge 210 and a second longitudinal edge 212. The inner liner 206 has an inner surface 214 and an outer surface 216. The sheet 208 is wound in a spiral configuration, as shown in FIG. 12, such that at least a portion of the inner surface 214 of the sheet 208 overlays at least a portion of the outer surface 216 of the sheet 208 forming an overlapping portion 218. As further shown in FIG. 12, in some examples, at least a portion of the outer surface 216 of the sheet 208 can comprise a plurality of bonding sites 240 that are at least partially embedded within the sheet 208. As exemplified in FIG. 12, these plurality of bonding sites 240 are disposed such that a portion of the outer surface 216 of the sheet 208 that has a portion of the inner surface 214 overlaying it in the overlapping portion 218 is substantially free of these bonding sites 240.

[0124] In some examples, in the disclosed coiled configuration of the inner liner 206, the first longitudinal edge 210 of the sheet 208 is slidable along at least a portion the inner surface 214 of the sheet 208, and the second longitudinal edge 212 is slidable along at least a portion of the outer surface 216 of the sheet 208.

[0125] In some examples, the sheet 208 has a predetermined thickness. In such aspects, the sheet 208 can have any thickness from about 0.002 inches to about 0.025 inches, including exemplary values of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, about 0.01, about 0.015, and about 0.02 inches. It is further understood that the predetermined thickness of the sheet 208 forming the inner liner 206 of any of the disclosed herein configurations can be varied depending on the desired amount of radial expansion, as well as the strength required. In such aspects, the plurality of bonding sites 240 as shown in the exemplary inner liner 206 of FIG. 12 can have a depth (the depth of the bonding sites 240 embedded within the sheet 208 itself) of no more than about 50% of any of the predetermined values of the sheet thickness disclosed above. For example, the depth of the plurality of bonding sites 240 can be no more than about 50 %, no more than about 45 %, no more than about 40 %, no more than about 35 %, no more than about 30 %, no more thanabout 25 %, no more than about 20 %, no more than about 15 %, no more than about 15 %, no more than about 10 %, or no more than about 5 % of the disclosed above predetermined thickness of the sheet 208.

[0126] In some examples, the bonding sites 240 are disposed at the outer surface 216 and are not embedded or only partially embedded within the sheet 208. In such aspects, the plurality of bonding sites 240 can also at least partially extend from the outer surface 216 of the sheet 208. In some examples, the extended portion of the plurality of bonding sites 240 can have a height of no more than about 50 %, no more than about 45 %, no more than about 40 %, no more than about 35 %, no more than about 30 %, no more than about 25 %, no more than about 20 %, no more than about 15 %, no more than about 15 %, no more than about 10 %, or no more than about 5 % of the disclosed above predetermined thickness of the sheet 208. In some examples, where the plurality of bonding sites 240 are both extend from the outer surface 216 of the sheet 208 and at least partially embedded within the sheet 208, the height and the depth of the plurality of bonding sites 240 is no more than about 50 %, no more than about 45 %, no more than about 40 %, no more than about 35 %, no more than about 30 %, no more than about 25 %, no more than about 20 %, no more than about 15 %, no more than about 15 %, no more than about 10 %, or no more than about 5 % of the disclosed above predetermined thickness of the sheet 208.

[0127] In some examples, the plurality of bonding sites 240 can have an average depth up to about 1 %, up to about 5 %, up to about 10 %, up to about 15 %, up to about 20 %, up to about 25%, up to about 30%, up to about 35 %, up to about 40 %, up to about 45 %, or up to about 50 % of the predetermined thickness of the sheet 208 itself. In some examples, the plurality of bonding sites 240 can have an average depth and an average height if at least a portion of such bonding sites 240 extends above the outer surface 216 up to up to about 1 %, up to about 5 %, up to about 10 %, up to about 15 %, up to about 20 %, up to about 25%, up to about 30%, up to about 35 %, up to about 40 %, up to about 45 %, or up to about 50 % of the predetermined thickness of the sheet 208 itself.

[0128] In aspects where the plurality of bonding sites 240 both embedded in the sheet 208 and extend above the outer surface 216, the depth and the height of such bonding sites 240 can be the same or different depending on the specific application. In some examples, the depth and / or height of each of the bonding sites 240 in the plurality of bonding sites 240 can be the same or different as well.

[0129] In some examples, the sheet 208 comprises a first polymer composition. In such aspects, the first polymer composition can comprise high density polyethylene,polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof. While in some examples, the sheet 208 can comprise a multilayer structure. In aspects where more than one layer is present, each layer can comprise the same material or different.

[0130] In some examples, the plurality of bonding sites 240 can comprise a second polymer composition. In such aspects, the second polymer composition is different from the first polymer composition. It is understood, however, that the first and second polymer compositions can also be substantially identical if needed and depending on the specific application. In some examples, the second polymer composition comprises a polyethylene, a polypropylene, a graft modified polyethylene or polypropylene, or a combination thereof. In some exemplary aspects, the second polymer composition can comprise grafted low-density polyethylene (LDPE), grafted medium density polyethylene, grafted ultra-low-density polyethylene (ULDPE), grafted high density polyethylene (HDPE), grafted heterogeneously branched linear low-density polyethylene (LLDPE), grafted homogeneously branched linear ethylene polymers and substantially linear ethylene polymers, grafted polypropylene, or ethylene-vinyl acetate (EVA), or any combination thereof.

[0131] For example and without limitations, the sheet 208 can comprise HDPE, while bonding sites 240 can comprise LDPE, or a terpolymer such as maleic anhydride modified polyolefin, for example, and without limitation, Orevac® (commercially available from Arkema), ethylene acrylic acid copolymers, such as DOW Chemical Primacor®, ethylene acrylate copolymers such as Lotryl® (commercially available from Arkema), ethylene glycidyl methacrylate copolymer, ethylene acrylic esters glycidyl methacrylate terpolymer such as Lotader® (commercially available from Arkema), ethylene acrylic esters maleic anhydride terpolymers such as Lotader® or Orevac® (commercially available from Arkema), or a combination thereof.

[0132] In some examples, the first polymer composition and the second polymer composition can be coextruded together to form the inner liner 206. It is understood that in the aspects where the second polymer composition is different from the first polymer composition, these two compositions are compatible with each other and do not cause delamination.

[0133] In some examples, that plurality of bonding sites 240 can be disposed along at least a portion of a length of the inner liner 206. In some examples, the plurality of bonding sites 240 can be disposed along all the length of the inner liner 206. While in further examples, the plurality of bonding sites 240 can be disposed on the outer surface 216 (that is not in the overlapping portion) of the sheet 208 abut the distal end of the inner liner 206. In some examples, the plurality of bonding sites 240 can be disposed on the outer surface 216 (that isnot in the overlapping portion 218) of the sheet 208 abut the proximal end of the inner liner 206.

[0134] In some aspects, the plurality of bonding sites 240 are disposed in a predetermined pattern allowing coupling with the outer layer (for example, the braided layer 54 and / or the elastomeric outer layer 58) and preventing an axial movement of the outer layer during passage of a medical device through the lumen 220 of the inner liner 206. In some examples, the pattern can be any pattern that is desired for the specific application and allowing bonding with the outer layer.

[0135] In some aspects, the plurality of bonding sites 240 are disposed in a predetermined pattern to bind the inner liner 206 to the outer layer without compromising the expansion of the inner liner 206 upon the passage of the medical device. It is understood that since the expansion can be achieved by sliding the first longitudinal edge 1 10 and the second longitudinal edge 112 and decreasing the overlapping portion 218, no bonding sites 240 are disposed within the overlapping portion 218 to avoid undesirable binding and restrictions in the sliding.

[0136] In some examples, the plurality of bonding sites 240 can have any desired shape. For example, and without limitations, the plurality of bonding sites 240 can have a regular shape, irregular shape, or any combination thereof. In some examples, the plurality of bonding sites 240 can comprise a regular shape, for example, continuous stripes along the length of the inner liner 206, or discontinuous shapes such as discontinuous circular shape, rectangular, rhombic, trapezoid shape, and the like. Again, it is understood that the plurality of bonding sites 240 can be at least partially embedded within the sheet 208, or fully embedded within the sheet 208, or at least partially extend above the outer surface 216 of the sheet 208. In any of these aspects, the shape of each of the plurality of bonding sites 240 can be the same or different, or it can be any variation of the shapes.

[0137] In some examples, each of the plurality of bonding sites 240 has a width of no more than about 50 %, no more than about 45 %, no more than about 40 %, no more than about 35 %, no more than about 30 %, no more than about 25 %, no more than about 20 %, no more than about 15 %, no more than about 15 %, no more than about 10 %, or no more than about 5 % of the disclosed above predetermined thickness of the sheet 208. While in some examples, each of the plurality of bonding sites 240 has a width up to about 1 %, up to about 5 %, up to about 10 %, up to about 15 %, up to about 20 %, up to about 25%, up to about 30%, up to about 35 %, up to about 40 %, up to about 45 %, or up to about 50 % of the disclosed above predetermined thickness of the sheet 208.

[0138] In yet further examples, each of the plurality of bonding sites 240 has a width of about IX to about 10X of the thickness of the plurality of bonding sites 240, including exemplary values of about 2X, about 3X, about 4X, about 5X, about 6X, about 7X, about 8X, and about 9X of the thickness of the plurality of bonding sites 240.

[0139] In some examples, each of the plurality of bonding sites 240 has a width from about 0.01” to about 0.15”, including exemplary values of about 0.015”, about 0.02”, about 0.025”, about 0.03”, about 0.035”, about 0.04”, about 0.045”, about 0.05”, about 0.055”, about 0.06”, about 0.065”, about 0.07”, about 0.075”, about 0.08”, about 0.085”, about 0.09”, about 0.095”, about 0.1”, about 0.11”, about 0.12”, about 0.13”, and about 0.14”.

[0140] In some examples, the plurality of bonding sites 240 can comprise one bonding site 240. While in further examples, the plurality of bonding sites 240 comprise at least two bonding sites 240. It is understood that the number of the bonding sites 240 can be specifically chosen depending on the desired application. It is further understood that each of the plurality bonding sites 240 can be disposed at a predetermined distance from each other, where this predetermined distance can be chosen depending on the desired application. In some examples, the number and location of the bonding sites 240 can be chosen to allow for a section of the outer jacket 123 to expand as the inner layers expand but supply adequate anchoring strength to substantially prevent axial movement of the outer jacket 123 relative to the inner layers during insertion and withdraw of the sheath 100 into the body and upon the passing of the medical device.

[0141] Any of the disclosed herein inner liners / layers, outer layers, and materials used to form the bonding sites 240 can be utilized without limitations. It is further understood that the plurality of bonding sites 240 disposed on the inner surface of the outer layer can have the same shape as the plurality of bonding sites 240 disposed on the outer surface 216 of the inner liner 206 as disclosed above. Any of the characteristics or features of the bonding sites 240 disposed on the outer surface 216 of the inner liner 206 are applicable to the plurality of bonding sites 240 disposed on the inner surface of the outer layer.

[0142] In some configurations, the sheath 100 provided herein can be coupled to the introducer device assembly 20. In some instances, it is desirable for the diameter of the sheath 100 to vary along the central axis 122 of the sheath 100. Specifically, as described herein with respect to FIG. 11, it can be desirable for a portion of the sheath 100 (particularly a portion adjacent the proximal end 102) to flare or taper radially outward so as to facilitate coupling with the sheath hub 24 and provide a transitional portion of the sheath assembly toaccommodate the push forces needed to move the prosthetic device 12 through the sheath hub 24 and into the sheath 100.

[0143] FIGS. 13A-15C illustrate various views of an example inner liner 306 according to an additional configuration. The inner liner 306 can be used with a sheath similar to the sheath 100 described herein in reference to FIGS. 1-12. Likewise, the inner liner 306 is similar to inner liner 106, 206 described in reference to FIGS. 1-12. Thus, similar reference numbers as those used for the examples shown in FIGS. 1-12 are used to reference similar features of the examples shown in FIGS. 13A-15C. Furthermore, any features in any other example disclosed herein (for example, liner 106 and / or liner 206) can be included in the example liner 306. 13A-13C. Similar to the liner 106 shown in FIGS. 1-11 and / or liner 206 shown in FIG. 12, the inner liner 306 can be used with a sheath including one or more of an inner layer 52, outer layer 58, braided layer 54, elastic layer 56, strain relief layer 129, and outer jacket 123, or combinations thereof.

[0144] As described herein, the construction of the inner liner 306 facilitates winding the sheet 308 in a spiraled configuration so as to from an inner liner 306 / sheath 100 having a flared / tapered profile that is centered about the central axis 122 of the sheath 100.

[0145] In some examples, forming a flared / tapered portion at the proximal end of the rolled or coiled inner liner can distort the profile of the sheath and interfere with its proper functioning. Specifically, in some examples, the lumen of the liner will extend nonuniformly about the central axis along the outwardly flared / tapered portion. Such misalignment / nonuniformity can impede the ingress or egress of medical devices through the lumen of the sheath. Accordingly, as described herein, it is desirable to form the rolled / coiled liner such that the changes in diameter between tubular and flared / tapered portions of the liner are gradual, thus reducing the push forces required to advance the prosthetic device into / through the sheath 100 as well as reducing push forced required to advance the sheath 100 through the subject’s vasculature. Accordingly, in some examples, it is desirable for the sheath to have an unexpanded first diameter that varies along its central axis while maintaining uniform longitudinal alignment about the central axis.

[0146] As shown in FIGS. 13A-13C, the example liner 306 includes gradual diameter changes between tubular and flared / tapered portions of the liner 306. In this example, the variable diameter inner liner 306 comprises a coiled cross-sectional shape similar to inner liner 106, 206. Accordingly, the inner liner 306 comprises a sheet 308 having a first longitudinal edge (similar to first edge 110, 210) and a second longitudinal edge 312 extending between a proximal end 302 and a distal end 304. The inner liner 306 has an innersurface and an outer surface 316 (similar to the inner and outer surfaces of inner liner 106, 206). The sheet 308 is wound in a spiral configuration such that at least a portion of the inner surface of the sheet 308 overlays at least a portion of the outer surface 316 of the sheet 308 forming an overlapping portion 318. When wound in the spiral configuration, the sheet 308 defines a central lumen 320 that extends along a central axis 322 of the inner liner 306.

[0147] As described herein, the sheath 100 / inner liner 306 is configured to locally expand from an unexpanded configuration in which the central lumen 320 has a first diameter to an expanded configuration in which the central lumen 320 has a second, larger, diameter. For example, the sheath 100 / inner liner 306 will expand due to an outwardly directed radial force exerted on the central lumen 320 of the inner liner 306by a medical device (e.g., prosthetic device 12) passing through the sheath 100. The inner liner 306is configured to then locally contract at least partially back to the unexpanded configuration as the medical device passes therethrough. Similarly, the sheath 100 / inner liner 306 is configured to move between an unexpanded configuration and an expanded configuration in response to an outwardly directed radial force on the central lumen 320 of the sheath 100. It is contemplated that movement of the inner liner 306 between the unexpanded and expanded configurations results in a corresponding movement of the various other layers of the sheath 100 between the unexpanded and expanded configurations.

[0148] Similar to the inner liner 106 described in reference to FIGS. 8A-11 and inner liner 206 described in reference to FIG. 12, the inner liner 306 is rolled or coiled such that at least a portion of the inner surface of the sheet 308 forming the inner liner 306 overlays at least a portion of the outer surface 316 of the sheet 308, forming an overlapping portion 318. When wound into the spiral configuration, the inner surface of the sheet 108 defines the central lumen 320 of the inner liner 306 such that the central lumen 320 extends along the central axis 322 of the sheath 100.

[0149] The inner liner 306 is configured such that a longitudinally-extending first edge of the sheet 308 is slidable along at least a portion the inner surface of the sheet 308, and a longitudinally -extending second edge 312 is slidable along at least a portion of the outer surface 316 of the sheet 308. Accordingly, the inner liner 306 (and thus the sheath 100) moves from the unexpanded configuration to the expanded configuration, for example, upon introduction of a medical device into the central lumen 320 of the sheath 100. During movement from the unexpanded to the expanded configuration, the first edge and the second edge 312 slide relative to each other and expand the inner liner 306 from a unexpanded first rest diameter (dr) to a second expanded diameter (de), thereby shortening the overlappingportion 318 of the inner liner 306. It is understood that the second expanded diameter (de) is configured to accommodate the medical device passing through the central lumen 320 of the sheath 100. As described herein, the sheath 100 contracts to / toward the unexpanded configuration / unexpanded first rest diameter (dr) after passage of the medical device through the central lumen 320 of the sheath 100.

[0150] As further shown in FIG. 13A, a first straight portion 324 of the second longitudinal edge 312 extends in a direction generally parallel with the longitudinal central axis 322 and an angled portion 326 of the second longitudinal edge 312 extends circumferentially about the central axis 322. As shown, the angled portion 326 of the second longitudinal edge 312 is disposed proximally (e.g., toward the proximal end 302 of the inner liner 306) relative to the first straight portion 324 and extends circumferentially at an oblique angle relative to the first straight portion 324 and the central axis 322 when the sheet 308 is rolled or coiled and wound into the spiral configuration. In the illustrated example, the first straight portion 324 of the second longitudinal edge 312 extends along a top aspect of the inner liner 306.

[0151] As provided herein and illustrated in FIGS. 13A-13C, the first rest diameter (dr) of the inner liner 306 varies along the central axis 322. In particular, as shown in FIG. 13A, the inner liner 306 has a flared / tapered section 328 adjacent the proximal end 302 and a tubular section 330 extending distally from the flared / tapered section 328 toward the distal end 304. As shown, a first rest diameter (dr2) of the flared / tapered section 328 varies along a length (L3) of the flared / tapered section 228. Specifically, the first rest diameter (dr2) of the flared / tapered section 328 progressively increases from the tubular section 330 of the inner liner 306 toward a first rest diameter (dri) of the most proximal extent of the proximal end 302 of the inner liner 306 / sheath 300. In other words, the flared / tapered section 328 flares radially outward in a proximal direction relative to the tubular section 330 and tapers radially inward in a distal direction relative to the proximal end 302, from which it extends.Accordingly, the first rest diameter (dr2) of the flared / tapered section 328 is smaller than the first rest diameter (dri) of the proximal end 302 but is greater than a first rest diameter (drs) of the tubular section 330. Likewise, in some examples, the inner diameter of the inner liner 306 has a progressively increasing diameter along the flared / tapered section 328 from the tubular section 330 toward the proximal end 302 of the inner liner 306 / sheath 100.

[0152] In some examples, the disparity between the first rest diameter (dr2) of the flared / tapered section 328 and the first rest diameter (drs) of the tubular section 330 arises due to the angled relationship between the first straight portion 324 and the angled portion 326 along the second longitudinal edge 312. Advantageously, in some examples, the angledportion 326 allows the first rest diameter (dr?) of the flared / tapered section 328 to gradually increase in diameter when the sheet 308 is wound into the spiral configuration. Moreover, in some examples, an offset along the length (L3) of the sheet 308 corresponding to an axial length of the angled portion 326 provides a flared / tapered section 328 that extends uniformly about the central axis 322. In other words, when the sheet 308 is wound into the spiral configuration, a sheath 300 is formed that is centered about the central axis 322 such that the radial distance between the central axis 322 and the inner liner 306 is equidistant at any given axial location along the central axis 322. Meanwhile, the first straight portion 324 extending in a direction generally parallel to the central axis 322 results in a generally constant first rest diameter (drj) of the tubular section 330 when the sheet 308 is wound into the spiral configuration, thereby forming the tubular section 330 that extends a length (L4), which corresponds to an axial length of the first straight portion 324. Because the central lumen 320 of the inner liner 306 remains uniformly centered about the central axis 322 for the entire length (LI) of the inner liner 306 / sheath 100, medical devices can be readily inserted and withdrawn through the central lumen 320 of the sheath 100.

[0153] In some examples, the length (L3) of the flared / tapered section 328 ranges from about 2 inches to about 6 inches. In some examples, the length (L3) of the flared / tapered section 328 is about 3 inches. However, the length (L3) can be adjusted by adjusting the axial length of the angled portion 326 of the second longitudinal edge 312. Furthermore, the degree of flare / taper can be controlled by adjusting the angle between the angled portion 326 and the first straight portion 324. For example, in some examples, obtaining a flared / tapered section 328 having a sharp transition in diameter from the first rest diameter da) of the tubular section 330 to the first rest diameter (dr) of the flared / tapered section 328 can be achieved by reducing the angle between the angled portion 326 and the first straight portion 324. Conversely, in some examples, a more gradual transition between the first rest diameter (dr3) of the tubular section 330 and the first rest diameter (dri) of the flared / tapered section 328 can be achieved by increasing the angle between the angled portion 326 and the first straight portion 324. Accordingly, the angle between the angled portion 326 and the first straight portion 324 can be any angle greater than 90° and less than 180°. Advantageously, adjusting the angle between the angled portion 326 and the first straight portion 324 so as to make the transition between the first rest diameter (d,2) of the flared / tapered section 328 first rest diameter (drj) of the tubular section 330 more gradual can make the overall profile of the inner liner 306 / sheath 100 smoother, thereby reducing the push forces required to insert the sheath 100 into the vasculature.

[0154] In some examples, the length (L4) of the tubular section 330 ranges from about 8 inches to about 20 inches. In some examples, the length (L4) of the tubular section 330 ranges from about 8 inches to about 15 inches. In some examples, the length (L4) of the tubular section 330 is about 11 inches. However, as described herein, the length (L4) of the tubular section 330 can be adjusted by adjusting the axial length of the first straight portion 324. In some use cases, having a sheath 100 with a relatively long tubular section 330 can facilitate access to subject anatomy distant from the insertion site. For example, interventions that include accessing the heart (such as TAVR) via the femoral artery. In such use cases, axial length of the first straight portion 324 can be increased. Conversely, in other use cases, having a sheath 300 with a relatively short tubular section 330 can facilitate access to subject anatomy that is closer to the insertion site. For example, interventions that include accessing the heart (such as TAVR) via the carotid, axillary, and / or subclavian arteries. In such use cases, the length (L4) of the tubular section 330 can be decreased by decreasing the axial length of the first straight portion 324.

[0155] In some examples, the first straight portion 324 can extend to the distal end 304 of the inner liner 306 / sheath 300. Thus, the tubular section 330 can extend all the way to the distal end 304. However, in some examples, the first straight portion 324 may terminate a distance offset from the distal end 304 to allow for a second angled portion to extend angularly from the first straight portion 324 toward the distal end 304 of the inner liner 306 / sheath 100. In such examples, the distal end 304 can be tapered radially inward toward a most distal tip of the distal end 304. In the example illustrated in FIG. 13 A, the first straight portion 324 extends all the way to the distal end 304, but a radially inward taper is achieved in the distal end 304 through other means. For example, coupling a tapered distal tip the end of an expandable sheath is provided in International Application No. PCT / US2022 / 032903, incorporated herein. Accordingly, the tubular section 330 tapers radially inward toward the distal end 304 such that the first rest diameter (dr3) of the tubular section 330 is greater than the first rest diameter (dr) at the distal end 304. Thus, the first rest diameter (dri) of the proximal end 302 and the first rest diameter (dr2) of the flared / tapered section 328 are also greater than the first rest diameter (dr4) at the distal end 304.

[0156] In the example illustrated in FIG. 13 A, the inner liner 306 further defines a proximal section 332 adjacent the most proximal extent of the proximal end 302 of the sheath 300 and extending distally therefrom between the proximal end 302 and the flared / tapered section 328 for a length (L2).

[0157] FIG. 13B illustrates the inner liner 306 of FIG. 13 A rotated 90° about the central axis 322 such that a side aspect of the inner liner 306 is shown. This view shows the angled portion 326 of the second longitudinal edge 312 extending circumferentially around the inner liner 306. Specifically, the angled portion 326 extends from a top aspect of the inner liner 306 to a bottom aspect of the inner liner 306.

[0158] FIG. 13C illustrates the inner liner 306 of FIG. 13 A rotated a full 180° about the central axis 322 such that the bottom aspect of the inner liner 306 is shown. As shown, a second straight portion 334 of the second longitudinal edge 312 extends proximally from the angled portion 326 in a direction generally parallel with the central axis 322 and the first straight portion 324. Thus, the second straight portion 334 extends along the proximal section 332 toward the proximal end 302. In the illustrated example, the second straight portion 334 extends all the way to the most proximal aspect of the proximal end 302.

[0159] In the examples illustrated in FIGS. 13A-13C, the proximal section 332 is tubular in shape, having a generally constant diameter corresponding to the first rest diameter (dri) at the distal end 304 when the sheet 308 is wound into the spiral configuration. This is a result of the second straight portion 334 of the second longitudinal edge 312 extending in a direction generally parallel with the central axis 322. As shown in FIG. 13C, the flared / tapered section 328 transitions into the proximal section 332 where the angled portion 326 of the second longitudinal edge 312 transitions into the second straight portion 334. Accordingly, the length (L2) of the proximal section 332 corresponds to an axial length of the second straight portion 334. In some examples described herein, the proximal section 332 has a tapered shape corresponding to the tapered section 328. For example, the proximal section 332 can extend from the tapered section 328 toward the proximal end 302 of the sheath 300 at the same taper as the tapered section 328. In other examples, the proximal section 332 can extend from the tapered section toward the proximal end 302 at a taper greater or less than the taper of the tapered section 328.

[0160] For example, in some implementations as provided in FIGS. 14A-14B, the example inner liner 306 includes a flared / tapered section 328 that extends all the way to the most proximal extend of the proximal end 302. Specifically, FIG. 14A shows a top view of a sheath 100 including inner liner 306 that includes a flared / tapered section 328 that flares radially outward relative to the tubular section 330 as well as a flared proximal section 332 that mimics the radially outward flare of the flared / tapered section 328, resulting in an extended flared / tapered region at the proximal end 302 of the sheath 100. This effect can be achieved by modifying the proximal end 302. For example FIG. 14B shows a cross-sectionalview of the sheath 100 of FIG. 14A. Note that the angled portion 326 of the second longitudinal edge 312 is not visible from this perspective. As shown in FIG. 14B, a longitudinal cut 350 can be made in the proximal end 302 of the sheath 100 that permits the proximal section 332 to flare radially outward toward the proximal end 302. In further examples, more than one longitudinal cut 350 can be made circumferentially about the proximal end 302. An example of this technique is provided in U.S. Provisional Application No. 63 / 663,256, which is incorporated herein. In other examples, the proximal section 332 can be constructed to flare radially outward by extending the angled portion 326 of the second longitudinal edge 312 farther toward the proximal end 302. For example, the proximal section 332 can be defined by a second angled portion of the second longitudinal edge 312 extending proximally from the first angled portion 326, where the second angled portion extends at an angle oblique relative to the central axis 322 that is different from that of the angled portion 326. In further examples, the angled portion 326 can extend all the way to the proximal end 302 of the sheath 100.

[0161] Therefore, the first rest diameter (dr / ) of the proximal section 332 can vary along the length L2 of the proximal section 332. Accordingly, in some examples, the sheath 100 can thus have a total flared / tapered region spanning both the length (L3) of the tapered section 328 and the length (L2) of the proximal section 332. In some examples, this combined length of (L3) and (L2) ranges from about 3 inches to about 7 inches. In some examples, the combined length (L3) and (L2) is about 3 inches. Furthermore, the proximal section 332 can include a first rest diameter (d,i) that is greater than the first rest diameter (dri) of the flared / tapered section 328. In some examples, the transition between the first rest diameter (dr2) of the flared / tapered section 328 and the first rest diameter (dri) of the proximal section 332 can be gradual.

[0162] FIGS. 15A-15C illustrate an example sheath 100, including inner liner 306, coupled to the sheath hub 24 of the introducer device assembly 20. Advantageously, as shown in FIG. 15A (and further in FIG. 15C), the increased first rest diameter (dri) afforded by the flared / tapered section 328 and optionally flared proximal section 332 provides a proximal end 302 of the sheath 300 that has a size and shape corresponding to the size and shape of the distal end of the sheath hub 24. FIG. 15B illustrates a bottom view of the example sheath 100 and sheath hub 24 of FIG. 15A. As shown, the angled portion 326 of the second longitudinal edge 312 transitions into the second straight portion 334 along the bottom aspect of the inner liner 306. Furthermore, because the second straight portion 334 extends all the way to the most proximal extent of the proximal end 302, the second longitudinal edge 312 extends intothe locking nut 25 of the introducer device assembly 20. FIG. 15C shows a cross-sectional side view of the example sheath 100 and sheath hub 24 of FIG. 15B taken along section line B-B. As shown, the proximal end 302 of the sheath 300 is received over the distal end of the sheath hub 24 and is held in place by a compression fit with the locking nut 25. A longitudinal cut 350 at the proximal end 302 of the inner liner 306 allows the proximal section 332 to flare such that a flare profile set by the tapered section 328 carries through the proximal section 332 to the proximal end 302.

[0163] As illustrated in FIG. 15C, the construction of the sheet 308 described herein facilitates winding of the sheet 308 to form a spiraled inner liner 306 of a sheath 100. Advantageously, in some examples, the lumen 320 of the resulting sheath 100 is both flared at the proximal end 302 and centered about the central axis 322 for the entire length (LI) of the sheath 100. Thus, medical devices can be readily inserted into the sheath hub 24 of the introducer device assembly 20, advanced through the central lumen 320 of the inner liner 306 / sheath 100 toward a target treatment site, and withdrawn through the same.

[0164] FIGS. 16A-16C illustrate various plan views of an example sheet 408 for forming an inner liner of an example expandable sheath 100. The sheet 408 can be used to form any inner liner similar to the inner liners 106, 206, 306 described herein in reference to FIGS. 8A- 15C. Thus, similar reference numbers as those used for the examples shown in FIGS. 8A-15C are used to reference similar features of the example shown in FIGS. 16A-16C.

[0165] As shown in FIG. 16A, the sheet 408 is defined between a proximal end 402 and a distal end 404. The sheet 408 includes a first longitudinal straight edge 423 and a second longitudinal straight edge 424 opposite the first longitudinal straight edge 423. A distal edge 405 of the sheet 408 defines the boundary of the distal end 404 and extends between the first longitudinal straight edge 423 and the second longitudinal straight edge 424. As shown in FIG. 16A, a first angled edge 425 extends from the first longitudinal straight edge 423 at an angle oblique to the first longitudinal straight edge 423, and a second angled edge 426 extends from the second longitudinal straight edge 424 at an angle oblique to the second longitudinal straight edge 424. Furthermore, FIG. 16A shows a third longitudinal straight edge 433 extending from the first angled edge 425 at an angle oblique to the first angled edge 425 and a fourth longitudinal straight edge 434 extending from the second angled edge 426 at an angle oblique to the second angled edge 426. A proximal edge 403 defines a boundary of the proximal end 402 and extends between the third longitudinal straight edge 433 and the fourth longitudinal straight edge 434.

[0166] Taken together, in some implementations, the first longitudinal straight edge 423, first angled edge 425, and third longitudinal straight edge 433 define a first longitudinal edge 410 of the sheet 408. Likewise, taken together, the second longitudinal straight edge 424, second angled edge 426, and fourth longitudinal straight edge 434 define a second longitudinal edge 412 of the sheet 408.

[0167] In the illustrated example, the first longitudinal straight edge 423 extends in a direction generally parallel (e.g., within 10 degrees, within 5 degrees of parallel) to the second longitudinal straight edge 424. Moreover, both the first longitudinal straight edge 423 and the second longitudinal straight edge 424 extend in a direction generally parallel with a centerline 421 of the sheet 408. Additionally, the first angled edge 425 is shown extending in a direction generally parallel to the second angled edge 426. Both the first angled edge 425 and the second angled edge 426 extend at angles oblique to the centerline 421.

[0168] Furthermore, the third longitudinal straight edge 433 is shown extending in a direction generally parallel (e.g., within 10 degrees, within 5 degrees of parallel) to the fourth longitudinal straight edge 434. In the illustrated example, both the third longitudinal straight edge 433 and the fourth longitudinal straight edge 434 extend in a direction generally parallel with the centerline 421 and generally parallel with the first longitudinal straight edge 423 and second longitudinal straight edge 424.

[0169] Further still, the distal edge 405 is shown extending in a direction generally parallel (e.g., within 10 degrees, within 5 degrees of parallel) to the proximal edge 403. Specifically, both the distal edge 405 and the proximal edge 403 extend in directions normal to the centerline 421. Accordingly, the first longitudinal straight edge 423 and the second longitudinal straight edge 424 extend generally perpendicular to the distal edge 405 and the proximal edge 403.

[0170] However, in other examples, the first longitudinal straight edge 423 and second longitudinal straight edge 424 can extend at oblique angles relative to each other and / or relative to the centerline 421. Likewise, in some examples, the third longitudinal straight edge 433 and fourth longitudinal straight edge 434 can extend at oblique angles relative to each other and / or relative to the centerline 421. Furthermore, in some examples, the distal edge 405 and / or the proximal edge 403 can extend at oblique angles relative to each other and / or relative to the centerline 421.

[0171] As contemplated herein, the sheet 408 can be wound into a spiral configuration analogous to sheath 300. Specifically, in some examples, the sheet 408 can be wound about the centerline 421 so as to form an inner liner having the advantages described herein inreference to the inner liner 306 shown in FIGS. 13A-15C. When the sheet 408 is wound into the spiral configuration, the axial lengths of the first longitudinal straight edge 423 and second longitudinal straight edge 424 correspond to at least the length (L4) of a tubular section 430 analogous to length (L4) of the tubular section 330. In some examples, this length defines both the length (L4) of the tubular section 430 and a residual length of a tapered distal end 404. In some examples, the length of the first longitudinal straight edge 423 and / or second longitudinal straight edge 424 corresponds with the length of the proximal section 432. For example, the first longitudinal straight edge 423 and / or second longitudinal straight edge 424 can have lengths ranging from about 8.0 inches to about 20.0 inches and the proximal section 432 has a corresponding length ranging from about 8.0 inches to about 20.0 inches. In some examples, the first longitudinal straight edge 423 and / or second longitudinal straight edge 424 can have lengths of about 11.0 inches such that the proximal section 432 also has a length of about 11.0 inches. In further examples, the first longitudinal straight edge 423 and / or second longitudinal straight edge 424 can have lengths of about 11.7 inches such that the proximal section 432 also has a length of about 11.7 inches.

[0172] Furthermore, the axial lengths of the first angled edge 425 and second angled edge 426 correspond to the length (L3) of a flared / tapered section 428 analogous to the length (L3) of the flared / tapered section 328. In some examples, the first angled edge 425 and / or second angled edge 426 can have lengths ranging from about 1.2 inches to about 7 inches such that the flared / tapered section 428 also has a corresponding length ranging from about 1.2 inches to about 7 inches. In some examples, the first angled edge 425 and / or second angled edge 426 can have lengths ranging from about 1.2 inches to about 3.2 inches such that the flared / tapered section 428 also has a corresponding length ranging from about 1.2 inches to about 3.2 inches. In some examples, the first angled edge 425 and / or second angled edge 426 can have lengths of about 2.2 inches such that the flared / tapered section 428 also has a length of about 2.2 inches.

[0173] Finally, the axial lengths of the third longitudinal straight edge 433 and fourth longitudinal straight edge 434 correspond to the length (L2) of a proximal section 432 analogous to length (L2) of the proximal section 332. In some examples, the third longitudinal straight edge 433 and / or the fourth longitudinal straight edge 434 can have lengths ranging from about 0.25 inches to about 1.0 inches such that the proximal section 432 also has a length ranging from about 0.25 inches to about 1.0 inches. In some examples, the third longitudinal straight edge 433 and / or the fourth longitudinal straight edge 434 can have lengths of about 0.7 inches such that the proximal section 432 also has a length of about 0.7inches. Furthermore, in the illustrated example, the third longitudinal straight edge 433 and the fourth longitudinal straight edge 434 are offset from the centerline 421 by a distance ranging from about 0.25 inches to about 0.75 inches. In some examples, the third longitudinal straight edge 433 and the fourth longitudinal straight edge 434 are offset from the centerline 421 by about 0.6 inches. This offset can determine the first rest diameter dri) of the proximal end 302 and / or proximal section 432 of the inner liner 406 / sheath 400.

[0174] As further shown in FIG. 16A, the sheet 408 can include a longitudinal cut 450 extending from the proximal edge 403. FIG. 16B shows an enlarged view of the longitudinal cut 450. As shown in FIGS. 16A-16B, the longitudinal cut 450 can extend generally perpendicular to the proximal edge 403, generally parallel to the centerline 421, generally parallel to the third longitudinal straight edge 433, and / or generally parallel to the fourth longitudinal straight edge 434. The illustrated example includes a plurality of longitudinal cuts 450 (e.g., at least 2, at least 3, at least 4, at least 5). As shown, the plurality of longitudinal cuts 450 includes three longitudinal cuts 450 spaced equidistant from each other. Specifically, the plurality of longitudinal cuts 450 are spaced about a distance ranging from about 0.25 to about 0.50 inches. For example, in some implementations, the plurality of longitudinal cuts 450 are spaced about 0.3 inches apart from each other. In some examples, the longitudinal cuts 450 extend along the sheet 408 a length ranging from 0.25 inches to about 0.50 inches. For example, in some implementations, the plurality of longitudinal cuts 450 extend along the sheet 408 a length of about 0.35 inches. As described above in reference to the longitudinal cut 350 of FIGS. 14A-15C, the longitudinal cut 450 permits the proximal section 432 to flare radially outward toward the proximal end 402 when the sheet 408 is wound into the spiral configuration. In some examples, the number, length and relative spacing of the longitudinal cuts 450 can be adjusted to control the degree of flaring achieved at the proximal end 402.

[0175] As further shown in FIG. 16A, the sheet 408 can include a radial cut 438 extending inward from the first longitudinal straight edge 423 of the first longitudinal edge 410. FIG. 16C shows an enlarged view of the radial cut 438. As shown in FIGS. 16A and 16C, the radial cut 438 is positioned adjacent the distal edge 405. In the illustrated example, the radial cut 438 extends generally perpendicular to the first longitudinal straight edge 423 of the first longitudinal edge 410. In some examples, including the illustrated example, the radial cut 438 is generally parallel to the distal edge 405. In other words, the radial cut 438 is generally perpendicular to the centerline 421. In some examples, it is contemplated that a plurality of radial cuts may be provided. When the sheet 408 is wound into the spiraled configuration, theradial cut 438 facilities formation of a tapered distal end 404 of the sheath. Specifically, the radial cut 438 allows for a tab of the sheet 408 between the radial cut 438 and the distal edge 405 to be folded so as to create a taper from the tubular section 430 toward the distal end 404.

[0176] As shown, the radial cut 438 is offset from the distal edge 405 a distance ranging from about 0.15 inches to about 0.50 inches. In some examples, the radial cut 438 is offset from the distal edge 405 by about 0.2 inches (or 5.0 centimeters). As shown in FIG. 16C, in some examples, the radial cut 438 extends into the sheet 408 from the first longitudinal straight edge 423 a distance ranging from about 0.25 inches to about 0.75 inches. In some examples, the radial cut 438 extends about 0.64 inches into the sheet 408 from the first longitudinal straight edge 423. However, the position of the radial cut 438 relative to the distal edge 405 and the length of the radial cut 438 can be adjusted so as to control the degree of taper.

[0177] In some aspects, the present disclosure relates to a mandrel used for cutting an exemplary sheet to make a sheet (for example, sheet 408 analogous sheet 308) suitable for winding into an inner liner (for example, inner liner 306) having the spiraled configuration as described herein in reference FIGS. 13A-16C.

[0178] FIGS. 17A-17C illustrate an example mandrel 500 used for cutting a sheet. FIG. 17A is a top view of the mandrel 500. FIG. 17B is a bottom view of the mandrel 500 rotated 180° relative to the view shown in FIG. 17A. FIG. 17C is a side view of the mandrel 500 rotated a further 90° relative to the view shown in FIG. 17B. As shown in FIG. 17A, the mandrel 500 includes a shaft 502 that extends between a proximal end 504 and a distal end 506. A tubular central region 508 of the shaft 502 extends between the proximal end 504 and the distal end 506 and defines a central axis 510 of the shaft 502 / mandrel 500. The proximal end 504 of the shaft 502 flares radially outward. In the illustrated example, the distal end 506 of the shaft 502 tapers radially inward. As shown in FIGS. 17A-17C, the shaft 502 defines a groove 512 extending between the proximal end 504 and the distal end 506. FIG. 17A shows a first straight portion 514 of the groove 512 extending generally parallel with the central axis 510 of the shaft 502. An angled portion 516 of the groove 512 extends circumferentially about the central axis 510 at an angle oblique to the central axis 510.

[0179] In some examples, including the illustrated example, the first straight portion 514 of the groove 512 extends along the tubular central region 508. As shown, the angled portion 516 of the groove 512 is disposed proximal to the first straight portion 514 of the groove 512. Specifically, as shown in FIG. 17A, the first straight portion 514 extends along a top aspect of the shaft 502 and intersects with a distal tip 522 of the distal end 506. In the illustrated example, the angled portion 516 of the groove 512 extends circumferentially 180° around theshaft 502. It is contemplated herein that in further examples, the angled portion 516 can extend more than 180° around the shaft 502. In some examples, the angled portion 516 can extend at least partially along the tubular central region 508 of the shaft 502 and at least partially along the proximal end 504 of the shaft 502.

[0180] In some examples, including the illustrated example, the groove 512 further defines a second straight portion 518 disposed proximal to the angled portion 516. As shown in FIG. 17B, the second straight portion 518 extends generally parallel with the central axis 510 of the shaft 502. Specifically, as shown in FIG. 17B, the second straight portion 518 extends along a bottom aspect of the shaft 502 and intersects with a proximal base 520 of the proximal end 504.

[0181] As provided herein, the various attributes of the sheet (for example sheets, 308, 408) formed from the mandrel 500 can be controlled by adjusting attributes of the mandrel 500. Accordingly, attributes of an inner liner (for example, inner liner 306) formed from the sheet can also be controlled.

[0182] For example, comparing the mandrel 500 and sheet 408, the axial length of the first straight portion 514 of the mandrel 500 can correspond to the axial lengths of the first longitudinal straight edge 423 and second longitudinal straight edge 424 of the sheet 408, thereby defining the length (L4) of the tubular section 430 of the inner liner 406 formed by the sheet 408. As provided herein the second longitudinal straight edge 424 is analogous to the first straight portion 324 of the sheath 300 and the tubular section 430 is analogous to the tubular section 330 of the sheath 300.

[0183] Additionally, the angle at which the angled portion 516 of the mandrel 500 extends from the first straight portion 514 can correspond to the angles at which the first angled edge 425 and second angled edge 426 extend from the first longitudinal straight edge 423 and second longitudinal straight edge 424 of the sheet 408. Furthermore, the axial length of the angled portion 516 can correspond to the axial lengths of the first angled edge 425 and second angled edge 426, thereby defining the length (L3) of the flared / tapered section 428 of the inner liner 406 formed by the sheet 408. As provided herein, the flared / tapered section 428 of the inner liner 406 is analogous to the flared / tapered section 328 of the inner liner 306.

[0184] Furthermore, an axial length of the second straight portion 518 can correspond to the axial lengths of the third longitudinal straight edge 433 and fourth longitudinal straight edge 434, thereby, defining the length (L2) of the proximal section 432. As provided herein, the proximal section 432 of the inner liner 406 is analogous to the proximal section 332 of the inner liner 306.

[0185] As contemplated herein, the sheet 408 can be wound into a spiral configuration analogous to inner liner 306. Specifically, the sheet 408 can be wound about the centerline 421 so as to form an inner liner 406 having the advantages described herein in reference to the inner liner 306 shown in FIGS. 13A-15C. When the sheet 408 is wound into the spiral configuration, the axial lengths of the first longitudinal straight edge 423 and second longitudinal straight edge 424 can correspond to at least the length (L4) of a tubular section 430 analogous to the tubular section 330. In some examples, this length defines both the length (L4) of the tubular section 430 and a residual length of a tapered distal end 404. In some examples, the first longitudinal straight edge 423 and / or second longitudinal straight edge 424 can have lengths of about 11.7 inches such that the proximal section 432 also has a length of about 11.7 inches. Furthermore, the axial lengths of the first angled edge 425 and second angled edge 426 can correspond to the length (L3) of a flared / tapered section 428 analogous to the flared / tapered section 328. In some examples, the first angled edge 425 and / or second angled edge 426 can have lengths of about 2.2 inches such that the flared / tapered section 428 also has a length of about 2.2 inches. In some examples, the axial lengths of the third longitudinal straight edge 433 and fourth longitudinal straight edge 434 can correspond to the length (L2) of a proximal section 432 analogous to the proximal section 332. In some examples, the third longitudinal straight edge 433 and / or the fourth longitudinal straight edge 434 can have lengths of about 0.7 inches such that the proximal section 432 also has a length of about 0.7 inches. Furthermore, in the illustrated example, the third longitudinal straight edge 433 and the fourth longitudinal straight edge 434 are offset from the centerline 421 by about 0.6 inches. This offset can determine the first rest diameter (dr / ) of the proximal end 302 and / or proximal section 432 of the inner liner 406 / sheath 400.

[0186] In some aspects, the present disclosure relates to a method of manufacturing and / or assembling an expandable sheath 100 including an inner liner 106, 206, 306, 406 according to the examples described herein is provided. In general, as described herein, the inner liner 106, 206, 306, 406 can comprise and / or be formed from a sheet 108, 208, 308, 408 that is wound into a spiraled configuration so as to form the inner liner 106, 206, 306, 406 of the sheath 100. As described herein, the inner liner / sheath has a flared / tapered profile that is centered about a central axis of the sheath 100.

[0187] Furthermore, any features in any other example disclosed herein (for example, FIG. 12) can be included in the example methods of manufacturing and / or assembly.

[0188] In some examples, a method of manufacturing the inner liner 406 of the sheath 400 includes forming the sheet 408. In some examples, this involves positioning an elongatedsingle lumen tubing having that has an inner surface 414 and an outer surface 416 about the shaft 502 of the mandrel 500. In some examples, the single lumen tubing is then cut along the first straight portion 514 so as to form the first longitudinal straight edge 423 and opposite second longitudinal straight edge 424. Then, in some examples, the single lumen tubing is further cut along the angled portion 516 so as to form the first angled edge 425 and opposite second angled edge 426. Further still, in some examples, the single lumen tubing is cut along the second straight portion 518 so as to form the third longitudinal straight edge 433 and opposite fourth longitudinal straight edge 434.

[0189] As provided herein, the first longitudinal edge 410 is inclusive of the first longitudinal straight edge 423, the first angled edge 425, and the third longitudinal straight edge 433, and the second longitudinal edge 412 is inclusive of the second longitudinal straight edge 424, the second angled edge 426, and the fourth longitudinal straight edge 434. Thus, a cut can be formed in the single lumen tubing that extends an entire length of the single lumen tubing.

[0190] Accordingly, cutting the single lumen tubing using the mandrel 500 as described herein can form the sheet 408. Subsequently, the sheet 408 can be wound into the spiraled configuration described herein to form the inner liner 406, in which the second longitudinal straight edge 424 extends over the first longitudinal straight edge 423 forming an overlapping portion 418. When wound in the spiral configuration, the sheet 408 defines a central lumen 420 that extends along a central axis 322 of the sheath 100 that is generally parallel to the centerline 421 of the sheet 408. As previously described herein, the various edges of the sheet 408 correspond to the various sections and features of the inner liner 406 formed from the sheet 408.

[0191] In some examples, coiling the sheet 408 can include positioning the sheet 408 about an annealing mandrel in a coiled configuration such that second longitudinal straight edge 424 moves over the first longitudinal straight edge 423. In some examples, the sheet 408 can be heat set into the coiled configuration when positioned around the annealing mandrel in the coiled configuration. As provided herein, coiling or rolling the sheet 408 can also include winding the sheet 408 into spiraled configuration about the central axis 422 such that a flared / tapered inner liner 406 / sheath 100 is formed that is centered about its central axis.

[0192] Exemplary Aspects

[0193] In view of the described processes and compositions, hereinbelow are described additional examples and aspects of the disclosures. These particularly recited aspects should not, however, be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein, or that the “particular” aspects aresomehow limited in some way other than the inherent meanings of the language and formulas literally used therein.

[0194] Example 1 : A sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end and comprises: an inner liner comprising a sheet having a first edge, a second edge, and a tapered section extending distally from the proximal end, wherein inner liner is wound in a spiral configuration that defines a central lumen that extends along a longitudinal central axis of the sheath, wherein the inner liner is configured to expand from an unexpanded configuration at a first rest diameter drto an expanded configuration at a second expanded diameter de by sliding the first edge of the sheet relative to the second edge of the sheet, and wherein the first rest diameter drvaries along the central axis.

[0195] Example 2: A sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end and comprises: an inner liner comprising a sheet having a longitudinally-extending first edge and a longitudinally-extending second edge, the inner liner being defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet forming an overlapping portion, wherein the inner surface of the sheet defines a central lumen that extends along a longitudinal central axis of the sheath, wherein a first straight portion of the second edge extends in a direction generally parallel with the central axis, and an angled portion of the second edge extends circumferentially about the central axis at an angle oblique to the central axis, wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, and wherein the inner liner is configured to expand from an unexpanded configuration at a first rest diameter d, to an expanded configuration at a second expanded diameter de by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of the outer surface during application of a radial outward force against the inner surface of the inner liner.

[0196] Example 3: The sheath according to any example herein, particularly example 2, wherein the first rest diameter drvaries along the central axis.

[0197] Example 4: The sheath according to any example herein, particularly examples 2-3, wherein the angled portion of the second edge is disposed proximal to the first straight portion of the second edge.

[0198] Example 5: The sheath according to any example herein, particularly examples 2-4, wherein the inner liner further comprises a tapered section extending distally from the proximal end.

[0199] Example 6: The sheath according to any example herein, particularly example 5, wherein a first rest diameter drof the tapered section varies along a length L3 of the tapered section.

[0200] Example 7: The sheath according to any example herein, particularly example 6, wherein the length L3 of the tapered section measures about 3 inches.

[0201] Example 8: The sheath according to any example herein, particularly examples 5-6, wherein the tapered section is uniformly centered about the central axis.

[0202] Example 9: The sheath according to any example herein, particularly examples 5-8, wherein the angled portion of the second edge extends along the tapered section of the inner liner.

[0203] Example 10: The sheath according to any example herein, particularly examples 5-9, wherein the inner liner further comprises a tubular section extending distally from the tapered section.

[0204] Example 11 : The sheath according to any example herein, particularly example 10, wherein a first rest diameter drj of the tubular section is generally constant along a length L4 of the tubular section.

[0205] Example 12: The sheath according to any example herein, particularly example 11, wherein the length L4 of the tubular section measures about 11 inches.

[0206] Example 13: The sheath according to any example herein, particularly examples 10-11 , wherein the first straight portion of the second edge extends along the tubular section of the inner liner.

[0207] Example 14: The sheath according to any example herein, particularly examples 11- 13, wherein, in the unexpanded configuration, the first rest diameter dr2 of the tapered section is greater than the first rest diameter drj of the tubular section.

[0208] Example 15: The sheath according to any example herein, particularly example 14, wherein the first rest diameter dr2 of the tapered section gradually transitions toward the first rest diameter dr.? of the tubular section.

[0209] Example 16: The sheath according to any example herein, particularly example 15, wherein, in the unexpanded configuration, the first rest diameter d,j of the inner liner at the tapered section is greater than the first rest diameter d, at the tubular section.

[0210] Example 17: The sheath according to any example herein, particularly examples 10-16, wherein the first straight portion of the second edge extends distally from the angled portion.

[0211] Example 18: The sheath according to any example herein, particularly examples 10-17, wherein the tubular section extends to the distal end of the inner liner.

[0212] Example 19: The sheath according to any example herein, particularly examples 2-18, wherein a second straight portion of the second edge extends in a direction generally parallel with the central axis.

[0213] Example 20: The sheath according to any example herein, particularly example 19, wherein the second straight portion of the second edge extends proximally from the angled portion.

[0214] Example 21: The sheath according to any example herein, particularly examples 2-20, wherein the inner liner further comprises a proximal section extending distally from the proximal end, the proximal end being disposed proximal to the tapered section.

[0215] Example 22: The sheath according to any example herein, particularly example 21, wherein a first rest diameter drz of the proximal section is generally constant along a length L2 of the proximal section.

[0216] Example 23: The sheath according to any example herein, particularly example 21, wherein a first rest diameter dr / of the proximal section varies along a length L2 of the proximal section.

[0217] Example 24: The sheath according to any example herein, particularly examples 22-23, wherein a combined length L2 of the proximal section and length L3 of the tapered section measures about 3 inches.

[0218] Example 25: The sheath according to any example herein, particularly examples 22-24, wherein, in the unexpanded configuration, the first rest diameter d,- / of the proximal section is greater than the first rest diameter d,2 of the tapered section.

[0219] Example 26: The sheath according to any example herein, particularly example 25, wherein the first rest diameter dr / of the proximal section gradually transitions toward the first rest diameter dr2 of the tapered section.

[0220] Example 27: The sheath according to any example herein, particularly examples 10- 26, wherein the tubular section tapers radially inward toward the distal end, wherein, in the unexpanded configuration, the first rest diameter d,-., of the tubular section is greater than a first rest diameter dr4 at the distal end.

[0221] Example 28: The sheath according to any example herein, particularly example 27, wherein, in the unexpanded configuration, the first rest diameter d,- / at the proximal end is greater than the first rest diameter d,v at the distal end.

[0222] Example 29: The sheath according to any example herein, particularly examples 2-28, wherein at least a portion of the outer surface of the sheet comprises a plurality of bonding sites that are at least partially embedded within the sheet and disposed such that the outer surface of the sheet in the overlapping portion is substantially free of the plurality of bonding sites.

[0223] Example 30: The sheath according to any example herein, particularly example 29, wherein the sheath further comprises an outer layer disposed on the outer surface of the sheet in the spiral configuration; wherein the outer layer is at least partially coupled to the outer surface of the sheet in the spiral configuration at the plurality of bonding sites.

[0224] Example 31 : The sheath according to any example herein, particularly example 29, wherein the sheet has a predetermined thickness.

[0225] Example 32: The sheath according to any example herein, particularly example 31, wherein each of the plurality of bonding sites have a depth of no more than 50 % of the predetermined thickness of the sheet.

[0226] Example 33: The sheath according to any example herein, particularly examples 29- 32, wherein the sheet comprises a first polymer composition.

[0227] Example 34: The sheath according to any example herein, particularly example 33, wherein the plurality of bonding sites comprise a second polymer composition that is different from the first polymer composition.

[0228] Example 35: The sheath according to any example herein, particularly example 34, wherein the first polymer composition and the second polymer composition are coextruded to form the inner liner.

[0229] Example 36: The sheath according to any example herein, particularly examples 29- 35 wherein the plurality of bonding sites are disposed along at least a portion of a length of the inner liner.

[0230] Example 37: The sheath according to any example herein, particularly examples 30- 36, wherein the plurality of bonding sites are disposed in a predetermined pattern allowing coupling with the outer layer and preventing an axial movement of the outer layer during passage of the medical device through the central lumen of the inner liner.

[0231] Example 38: The sheath according to any example herein, particularly examples 29-37, wherein the plurality of bonding sites comprise a regular shape, irregular shape, or any combination thereof.

[0232] Example 39: The sheath according to any example herein, particularly examples 31-38, wherein each of the plurality of bonding sites has a width of about IX to about 10X of the thickness of the plurality of bonding sites.

[0233] Example 40: The sheath according to any example herein, particularly examples 33-39, wherein the plurality of bonding sites comprises at least two bonding sites.

[0234] Example 41: The sheath according to any example herein, particularly examples 33-40, wherein the first polymer composition comprises high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof.

[0235] Example 42: The sheath according to any example herein, particularly examples 29-41, wherein the sheet comprises a multilayer structure.

[0236] Example 43: The sheath according to any example herein, particularly example 42, wherein each layer of the multilayer structure comprises a polymer composition that is the same or different.

[0237] Example 44: The sheath according to any example herein, particularly examples 34- 43, wherein the second polymer composition comprises a polyethylene, a polypropylene, a graft modified polyethylene or polypropylene, or a combination thereof.

[0238] Example 45: The sheath according to any example herein, particularly examples 34- 43„ wherein the second polymer composition comprises grafted low-density polyethylene (LDPE), grafted medium density polyethylene, grafted ultra-low-density polyethylene (ULDPE), grafted high density polyethylene (HD PE), grafted heterogeneously branched linear low-density polyethylene (LLDPE), grafted homogeneously branched linear ethylene polymers and substantially linear ethylene polymers, grafted polypropylene, or ethylene-vinyl acetate (EVA), or any combination thereof.

[0239] Example 46: The sheath according to any example herein, particularly examples 29-45, wherein the second expanded diameter de is configured to accommodate the medical device passing through the central lumen.

[0240] Example 47 : The sheath according to any example herein, particularly examples 29-46, wherein the sheath contracts to a diameter that is substantially identical to the first rest diameter drafter removal of the radial outward force against the inner surface of the inner liner.

[0241] Example 48: The sheath according to any example herein, particularly examples 29-47, wherein the inner surface of the inner liner is at least partially ribbed.

[0242] Example 49: The sheath according to any example herein, particularly examples 29-48, wherein the inner liner is lubricious and has a coefficient of friction less than about 0.5.

[0243] Example 50: The sheath according to any example herein, particularly examples SO-49, wherein the outer layer comprises a polyether block amide, a styrene-based elastomer, polyurethane, latex, copolymers thereof, blends thereof, or extrudates of thereof.

[0244] Example 51 : The sheath according to any example herein, particularly example 50, wherein the outer layer comprises one or more layers.

[0245] Example 52: The sheath according to any example herein, particularly example 51, wherein at least one layer comprises the polyether block amide.

[0246] Example 53: The sheath according to any example herein, particularly example 52 wherein at least one layer comprises the styrene -based elastomer.

[0247] Example 54: The sheath according to any example herein, particularly examples 51-53, wherein at least one layer comprises polyurethane.

[0248] Example 55: The sheath according to any example herein, particularly example 53 or54, wherein at least one layer comprises a blend of the styrene-based elastomer and polyurethane.

[0249] Example 56: The sheath according to any example herein, particularly examples 53- 55 wherein the styrene-based elastomer has a Shore A durometer between 20A to 50A.

[0250] Example 57: The sheath according to any example herein, particularly examples 30- 56, wherein the outer layer comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising: from greater than 0 wt% to less than wt% of a first polymer comprising a polyether block amide, a polyurethane, or a combination thereof based on a total weight of the first compound composition; less than about 65 % of an inorganic filler based on a total weight of the first compound composition; and up to about 20 % of a solid lubricant filler based on a total weight of the first compound composition; wherein the sheath exhibits at least a 10 % reduction in an insertion force when compared with a substantially identical reference sheath that does not comprise the first polymer layer; and wherein the outer layer is substantially kink resistant.

[0251] Example 58: The sheath according to any example herein, particularly example 57, wherein a durometer of the first polymer at a proximal end of the outer layer is different from a durometer of the first polymer at a distal end of the outer layer and has a Shore D from about 20D to about 35D.

[0252] Example 59: The sheath according to any example herein, particularly examples 57- 58, wherein the first polymer comprises polyether block amide elastomer.

[0253] Example 60: The sheath according to any example herein, particularly examples 57- 59 wherein the first polymer comprises polyurethane.

[0254] Example 61: The sheath according to any example herein, particularly examples 57-60, wherein the inorganic filler comprises bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin clay, limestone, or any combination thereof and is present in an amount of at least about 10 % based on a total weight of the first compound composition.

[0255] Example 62: The sheath according to any example herein, particularly examples 57-61, wherein the inorganic filler is present in an amount of less than about 50 % based on a total weight of the first compound composition.

[0256] Example 63: The sheath according to any example herein, particularly examples 57-62, wherein the solid lubricant filler comprises a PTFE filler.

[0257] Example 64: The sheath according to any example herein, particularly examples 57-63, wherein the first compound composition further comprises at least one tackiness reducing compound present in an amount from about 1 % to about 20 % based on a total weight of the first compound composition.

[0258] Example 65: The sheath according to any example herein, particularly examples 57-64, wherein the outer layer comprises two or more polymer layers.

[0259] Example 66: The sheath according to any example herein, particularly example 65, wherein the outer layer comprises a second polymer layer comprising a second compound composition comprising from greater than 0 wt% to wt% of a second polymer comprising polyether block amide, a polyurethane, or a composition thereof; and wherein the second polymer has a Shore A Durometer from about 20A to about 65A.

[0260] Example 67 : The sheath according to any example herein, particularly example 66, wherein the second compound composition further comprises up to 20 % of tackiness reducing additive based on a total weight of the second compound composition.

[0261] Example 68: The sheath according to any example herein, particularly examples 66-67, wherein the second polymer comprises polyurethane.

[0262] Example 69: The sheath according to any example herein, particularly examples 66-68, wherein the outer layer has a predetermined thickness, and wherein at least about 50% of the predetermined thickness comprises the first and / or the second compound composition.

[0263] Example 70: The sheath according to any example herein, particularly examples 66- 69, wherein one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.

[0264] Example 71: The sheath according to any example herein, particularly example 70, wherein the one or more additional polymer layers comprise at least one intermediate reinforcement layer extending axially at least a portion of a length of the outer layer.

[0265] Example 72: The sheath according to any example herein, particularly example 71, wherein the at least one intermediate reinforcement layer comprises the first polymer, the second polymer, a polyolefin-based polymer, or a combination thereof.

[0266] Example 73: The sheath according to any example herein, particularly example 71 or72, wherein the at least one intermediate reinforcement layer comprises a material having a Shore D durometer from about 45D to about 76D.

[0267] Example 74: The sheath according to any example herein, particularly examples 71-73, wherein the at least one intermediate reinforcement layer is configured to thermally bond with the first polymer layer, the second polymer layer, or a combination thereof.

[0268] Example 75: The sheath according to any example herein, particularly examples 30- 74 wherein the sheath further comprises a braided layer disposed between the inner liner and the outer layer.

[0269] Example 76: The sheath according to any example herein, particularly example 75, wherein the braided layer is at least partially embedded within the outer layer.

[0270] Example 77: The sheath according to any example herein, particularly examples 30- 76, wherein the sheath comprises a lubricant at least partially disposed between the inner liner and the outer layer.

[0271] Example 78: A sheet for forming an inner liner of a sheath, the sheet defined between a proximal end and a distal end, and comprising: a first longitudinal edge and a second longitudinal edge opposite the first longitudinal edge; a distal edge at the distal end of the sheet extending between the first longitudinal edge and the second longitudinal edge; a first angled edge extending from the first longitudinal edge at an angle oblique to the first longitudinal edge; a second angled edge extending from the second longitudinal edge at an angle oblique to the second longitudinal edge; a third longitudinal edge extending from the first angled edge at an angle oblique to the first angled edge; a fourth longitudinal edge extending from the second angled edge at an angle oblique to the second angled edge; and a proximal edge at the proximal end of the sheet extending between the third longitudinal edge and the fourth longitudinal edge.

[0272] Example 79: The sheet according to any example herein, particularly example 78, wherein the first longitudinal edge extends in a direction generally parallel to the second longitudinal edge.

[0273] Example 80: The sheet according to any example herein, particularly examples 78-79, wherein the first angled edge extends in a direction generally parallel to the second angled edge.

[0274] Example 81: The sheet according to any example herein, particularly examples 78-80, wherein the distal edge extends in a direction generally parallel to the proximal edge.

[0275] Example 82: The sheet according to any example herein, particularly examples 78-81, wherein the third longitudinal edge has a length of 0.7 inches.

[0276] Example 83: The sheet according to any example herein, particularly examples 78-82, wherein the fourth longitudinal edge has a length of 0.7 inches.

[0277] Example 84: The sheet according to any example herein, particularly examples 78-83, wherein the third longitudinal edge extends in a direction generally parallel to the fourth longitudinal edge.

[0278] Example 85: The sheet according to any example herein, particularly examples 78-84, wherein the third longitudinal edge extends in a direction generally parallel to the first longitudinal edge.

[0279] Example 86: The sheet according to any example herein, particularly examples 78-85, wherein the fourth longitudinal edge extends in a direction generally parallel to the second longitudinal edge.

[0280] Example 87: The sheet according to any example herein, particularly examples 78-86, wherein the first longitudinal edge extends in a direction generally perpendicular to the proximal edge and the distal edge.

[0281] Example 88: The sheet according to any example herein, particularly examples 78-87, wherein the second longitudinal edge extends in a direction generally perpendicular to the proximal edge and the distal edge.

[0282] Example 89: The sheet according to any example herein, particularly examples 78-88, wherein the sheet further comprises a radial cut extending from the first longitudinal edge adjacent the distal edge, wherein the radial cut extending generally perpendicular to the first longitudinal edge and / or generally parallel to the distal edge.

[0283] Example 90: The sheet according to any example herein, particularly example 89, wherein the radial cut has a length of 0.64 inches.

[0284] Example 91: The sheet according to any example herein, particularly examples 89-90, wherein the radial cut is disposed 0.2 inches from the distal edge.

[0285] Example 92: The sheet according to any example herein, particularly examples 78-91, wherein the sheet further comprises a longitudinal cut extending from the proximal edge, wherein the longitudinal cut extends generally perpendicular to the proximal edge and / or generally parallel to the third longitudinal edge and / or the fourth longitudinal edge.

[0286] Example 93: The sheet according to any example herein, particularly example 92, wherein the longitudinal cut includes a plurality of longitudinal cuts spaced apart from each other along the proximal edge.

[0287] Example 94: The sheet according to any example herein, particularly example 92, wherein plurality of longitudinal cuts are spaced equidistant from each other.

[0288] Example 95: The sheet according to any example herein, particularly example 94, wherein each cut of the plurality of longitudinal cuts are spaced 0.3 inches apart.

[0289] Example 96: The sheet according to any example herein, particularly examples 93-95, wherein each cut of the plurality of longitudinal cuts has a length of 0.35 inches.

[0290] Example 97: The sheet according to any example herein, particularly examples 93-96, wherein the plurality of longitudinal cuts comprises 3 cuts.

[0291] Example 98: A mandrel for forming a sheath, the mandrel comprising: a shaft having a proximal end, a distal end, and a tubular central region extending therebetween, the tubular central region defining a central axis of the shaft, wherein the proximal end of the shaft flares radially outward, and the distal end of the shaft tapers radially inward, wherein the shaft defines a groove extending between the proximal end and the distal end, and wherein a first straight portion of the groove extends generally parallel with the central axis of the shaft, and an angled portion of the groove extends circumferentially about the central axis at an angle oblique to the central axis.

[0292] Example 99: The mandrel according to any example herein, particularly example 98, wherein the first straight portion of the groove extends along the tubular central region.

[0293] Example 100: The mandrel according to any example herein, particularly examples 98-99, wherein the angled portion of the groove is disposed proximal to the first straight portion of the groove.

[0294] Example 101: The mandrel according to any example herein, particularly examples 98-100, wherein the angled portion of the groove extends circumferentially 180° around the shaft.

[0295] Example 102: The mandrel according to any example herein, particularly examples 98-101, wherein the angled portion of the groove extends at least partially along the tubular central region of the shaft and at least partially along the proximal end of the shaft.

[0296] Example 103: The mandrel according to any example herein, particularly examples 98-102, wherein the groove further defines a second straight portion disposed proximal to the angled portion and extending generally parallel with the central axis of the shaft.

[0297] Example 104: The mandrel according to any example herein, particularly examples 98-103, wherein the first straight portion of the groove extends to a distal tip of the distal end of the shaft.

[0298] Example 105: The mandrel according to any example herein, particularly examples 103-104, wherein the second straight portion of the groove extends to a proximal base of the proximal end of the shaft.

[0299] Example 106: A method of making an inner liner of a sheath, the method comprising: (1) forming a sheet by: providing an elongated single lumen tubing having an inner surface and an outer surface; positioning the elongated single lumen tubing about a shaft of a mandrel, the shaft comprising a proximal end, a distal end, and a tubular central region extending therebetween, the tubular central region defining a central axis of the shaft; wherein the shaft defines a groove extending between the proximal end and the distal end, and wherein a first straight portion of the groove extends generally parallel with the central axis of the shaft, and an angled portion of the groove extends circumferentially about a central axis at an angle oblique to the central axis, and cutting the elongated single lumen tubing along the first straight portion and angled portion of the groove so as to form a sheet comprising a first longitudinal edge and a second longitudinal edge opposite the first longitudinal straight edge; and (2) coiling the sheet such that the second longitudinal edge extends over the first longitudinal edge, thereby forming the inner liner.

[0300] Example 107: The method according to any example herein, particularly example 106, wherein the first longitudinal edge further comprises a first longitudinal straight edge and a first angled edge extending from the first longitudinal straight edge at an angle oblique to the first longitudinal straight edge; and wherein the second longitudinal edge further comprises a second longitudinal straight edge and a second angled edge opposite the first angled edge and extending from the second longitudinal straight edge at an angle oblique to the second longitudinal straight edge.

[0301] Example 108: The method according to any example herein, particularly examples 106-107, wherein the first straight portion of the groove extends along the tubular central region.

[0302] Example 109: The method according to any example herein, particularly examples 106-108, wherein the angled portion of the groove is disposed proximal the first straight portion of the groove.

[0303] Example 110: The method according to any example herein, particularly examples 106-109, wherein the angled portion of the groove extends circumferentially 180° around the shaft.

[0304] Example 111: The method according to any example herein, particularly examples 106-110, wherein the angled portion of the groove extends at least partially along the tubular central region of the shaft and at least partially along the proximal end of the shaft.

[0305] Example 112: The method according to any example herein, particularly examples 106-111, wherein the groove further defines a second straight portion disposed proximal the angled portion and extending generally parallel with the central axis of the shaft.

[0306] Example 113: The method according to any example herein, particularly example 112, wherein forming the sheet further comprises cutting the sheet along the second straight portion so as to form a third longitudinal straight edge of the sheet and a fourth longitudinal straight edge of the sheet opposite the third longitudinal straight edge.

[0307] Example 114: The method according to any example herein, particularly examples 106-113, wherein the first straight portion of the groove extends to a distal tip of the distal end of the shaft.

[0308] Example 115: The method according to any example herein, particularly examples 106-114, wherein the second straight portion of the groove extends to a proximal base of the proximal end of the shaft.

[0309] Example 116: The method according to any example herein, particularly examples 106-115, wherein cutting the single lumen tubing forms a cut extending an entire length of the single lumen tubing.

[0310] Example 117: The method according to any example herein, particularly examples 113-116, wherein the sheet further comprises: a distal edge at the distal end of the sheet extending between the first longitudinal edge and the second longitudinal edge; and a proximal edge at the proximal end of the sheet extending between the third longitudinal edge and the fourth longitudinal edge.

[0311] Example 118: The method according to any example herein, particularly examples 106-117, wherein the proximal end of the shaft flares radially outward, and the distal end of the shaft tapers radially inward.

[0312] Example 119: The method according to any example herein, particularly examples 106-118, wherein coiling the sheet further comprises positioning the sheet about an annealing mandrel in a coiled configuration such that the second longitudinal straight edge moves over the first longitudinal straight edge.

[0313] Example 120: The method according to any example herein, particularly example 119, wherein coiling the sheet further comprises heat-setting the sheet when it is in the coiled configuration.

[0314] Example 121: A sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end and comprises: an inner liner comprising a sheet, the inner liner having a longitudinally -extending first edge, a longitudinally-extending second edge, an inner surface, and an outer surface, wherein the inner liner is wound in a spiral configuration such that at least a portion of the inner surface of overlays at least a portion of the outer surface forming an overlapping portion, wherein the inner surface defines a central lumen that extends along a longitudinal central axis of the sheath, wherein a first straight portion of the second edge extends in a direction generally parallel with the central axis, and an angled portion of the second edge extends circumferentially about the central axis at an angle oblique to the central axis, wherein the first edge is slidable along at least a portion the inner surface and the second edge is slidable along at least a portion of the outer surface, and wherein the inner liner is configured to expand from an unexpanded configuration at a first rest diameter dr to an expanded configuration at a second expanded diameter de, during which at least a portion of the first edge of the sheet slides along at least a portion of the inner surface, and at least a portion of the second edge of the sheet slides along at least a portion of the outer surface.

[0315] Example 122. The sheath of example 121, wherein the inner liner is configured to expand during application of a radial outward force against the inner surface of the inner liner.

[0316] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

[0317] Any of the various systems, assemblies, devices, components, apparatuses, etc. in this disclosure can be sterilized (e.g., with heat, radiation, ethylene oxide, hydrogen peroxide, etc.) to ensure they are safe for use with patients, and the methods herein can comprise (oradditional methods comprise or consist of) sterilization of the associated system, device, component, apparatus, etc. (e.g., with heat, radiation, ethylene oxide, hydrogen peroxide, etc.).

[0318] No language in the specification should be construed as indicating any non-claimed element essential to the practice of the disclosure.

[0319] Groupings of alternative elements or implementations of the disclosure herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0320] All structural and functional equivalents to the components of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

[0321] In view of the many possible aspects to which the principles of the disclosed disclosure can be applied, it should be recognized that the illustrated aspects are only examples of the disclosure and should not be taken as limiting the scope of the disclosure. Rather, the scope of the disclosure is defined by the following claims. We, therefore, claim as our disclosure all that comes within the scope and spirit of these claims.

Claims

CLAIMSWhat is claimed is:

1. A sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end and comprises: an inner liner comprising a sheet having a longitudinally-extending first edge and a longitudinally-extending second edge, the inner liner being defined by an inner surface and an outer surface, wherein the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlays at least a portion of the outer surface of the sheet forming an overlapping portion, wherein the inner surface of the sheet defines a central lumen that extends along a longitudinal central axis of the sheath, wherein a first straight portion of the second edge extends in a direction generally parallel with the central axis, and an angled portion of the second edge extends circumferentially about the central axis at an angle oblique to the central axis, wherein the first edge of the sheet is slidable along at least a portion the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, and wherein the inner liner is configured to expand from an unexpanded configuration at a first rest diameter drto an expanded configuration at a second expanded diameter deby sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along the at least a portion of the outer surface during application of a radial outward force against the inner surface of the inner liner.

2. The sheath of claim 1, wherein the first rest diameter drvaries along the central axis.

3. The sheath of any of claims 1-2, wherein the angled portion of the second edge is disposed proximal to the first straight portion of the second edge.

4. The sheath of any of claims 1-3, wherein the inner liner further comprises a tapered section extending distally from the proximal end, wherein a first rest diameter d,-2 of the tapered section varies along a length L3 of the tapered section.

5. The sheath of any of claims 1-4, wherein the angled portion of the second edge extends along the tapered section of the inner liner.

6. The sheath of any of claims 1-5, wherein the inner liner further comprises a tubular section extending distally from the tapered section, wherein the first straight portion of the second edge extends along the tubular section of the inner liner.

7. The sheath of claim 6, wherein the first straight portion of the second edge extends distally from the angled portion.

8. The sheath of any of claims 1-7, wherein at least a portion of the outer surface of the sheet comprises a plurality of bonding sites that are at least partially embedded within the sheet and disposed such that the outer surface of the sheet in the overlapping portion is substantially free of the plurality of bonding sites.

9. A sheet for forming an inner liner of a sheath, the sheet defined between a proximal end and a distal end, and comprising: a first longitudinal edge and a second longitudinal edge opposite the first longitudinal edge; a distal edge at the distal end of the sheet extending between the first longitudinal edge and the second longitudinal edge; a first angled edge extending from the first longitudinal edge at an angle oblique to the first longitudinal edge; a second angled edge extending from the second longitudinal edge at an angle oblique to the second longitudinal edge; a third longitudinal edge extending from the first angled edge at an angle oblique to the first angled edge; a fourth longitudinal edge extending from the second angled edge at an angle oblique to the second angled edge; and a proximal edge at the proximal end of the sheet extending between the third longitudinal edge and the fourth longitudinal edge.

10. The sheet of claim 9, wherein the first longitudinal edge extends in a direction generally parallel to the second longitudinal edge, and wherein the first angled edge extends in a direction generally parallel to the second angled edge.

11. The sheet of any of claims 9-10, wherein the third longitudinal edge extends in a direction generally parallel to the fourth longitudinal edge,wherein the third longitudinal edge extends in a direction generally parallel to the first longitudinal edge, wherein the fourth longitudinal edge extends in a direction generally parallel to the second longitudinal edge.

12. The sheet of any of claims 9-11, wherein the sheet further comprises a radial cut extending from the first longitudinal edge adjacent the distal edge, wherein the radial cut extending generally perpendicular to the first longitudinal edge and / or generally parallel to the distal edge.

13. The sheet of any of claims 9-12, wherein the sheet further comprises a longitudinal cut extending from the proximal edge, wherein the longitudinal cut extends generally perpendicular to the proximal edge and / or generally parallel to the third longitudinal edge and / or the fourth longitudinal edge, wherein the longitudinal cut includes a plurality of longitudinal cuts spaced apart from each other along the proximal edge.

14. A mandrel for forming a sheath, the mandrel comprising: a shaft having a proximal end, a distal end, and a tubular central region extending therebetween, the tubular central region defining a central axis of the shaft, wherein the proximal end of the shaft flares radially outward, and the distal end of the shaft tapers radially inward, wherein the shaft defines a groove extending between the proximal end and the distal end, and wherein a first straight portion of the groove extends generally parallel with the central axis of the shaft, and an angled portion of the groove extends circumferentially about the central axis at an angle oblique to the central axis.

15. The mandrel of claim 14, wherein the first straight portion of the groove extends along the tubular central region.

16. The mandrel of any of claims 14-15, wherein the angled portion of the groove is disposed proximal to the first straight portion of the groove.

17. The mandrel of any of claims 14-16, wherein the angled portion of the groove extends circumferentially 180° around the shaft.

18. The mandrel of any of claims 14-17, wherein the angled portion of the groove extends at least partially along the tubular central region of the shaft and at least partially along the proximal end of the shaft, wherein the groove further defines a second straight portion disposed proximal to the angled portion and extending generally parallel with the central axis of the shaft, wherein the first straight portion of the groove extends to a distal tip of the distal end of the shaft, wherein the second straight portion of the groove extends to a proximal base of the proximal end of the shaft.

19. A method of making an inner liner of a sheath, the method comprising:(1) forming a sheet by: providing an elongated single lumen tubing having an inner surface and an outer surface: positioning the elongated single lumen tubing about a shaft of a mandrel, the shaft comprising a proximal end, a distal end, and a tubular central region extending therebetween, the tubular central region defining a central axis of the shaft; wherein the shaft defines a groove extending between the proximal end and the distal end, and wherein a first straight portion of the groove extends generally parallel with the central axis of the shaft, and an angled portion of the groove extends circumferentially about a central axis at an angle oblique to the central axis, and cutting the elongated single lumen tubing along the first straight portion and angled portion of the groove so as to form a sheet comprising a first longitudinal edge and a second longitudinal edge opposite the first longitudinal edge; and(2) coiling the sheet such that the second longitudinal edge extends over the first longitudinal edge, thereby forming the inner liner.

20. The method of claim 19, wherein the first longitudinal edge further comprises a first longitudinal straight edge and a first angled edge extending from the first longitudinal straight edge at an angle oblique to the first longitudinal straight edge; andwherein the second longitudinal edge further comprises a second longitudinal straight edge and a second angled edge opposite the first angled edge and extending from the second longitudinal straight edge at an angle oblique to the second longitudinal straight edge, wherein the first straight portion of the groove extends along the tubular central region and the angled portion of the groove is disposed proximal the first straight portion of the groove, where the angled portion of the groove extends circumferentially 180° around the shaft.

21. A sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end and comprises: an inner liner comprising a sheet, the inner liner having a longitudinally -extending first edge, a longitudinally-extending second edge, an inner surface, and an outer surface, wherein the inner liner is wound in a spiral configuration such that at least a portion of the inner surface of overlays at least a portion of the outer surface forming an overlapping portion, wherein the inner surface defines a central lumen that extends along a longitudinal central axis of the sheath, wherein a first straight portion of the second edge extends in a direction generally parallel with the central axis, and an angled portion of the second edge extends circumferentially about the central axis at an angle oblique to the central axis, wherein the first edge is slidable along at least a portion the inner surface and the second edge is slidable along at least a portion of the outer surface, and wherein the inner liner is configured to expand from an unexpanded configuration at a first rest diameter drto an expanded configuration at a second expanded diameter de, during which at least a portion of the first edge of the sheet slides along at least a portion of the inner surface, and at least a portion of the second edge of the sheet slides along at least a portion of the outer surface.

22. The sheath of claim 21, wherein the inner liner is configured to expand during application of a radial outward force against the inner surface of the inner liner.

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