Pre-shaped and atraumatic tips of expandable sheaths

Abstract

Disclosed herein are introducer sheaths and methods of using the same. The sheaths (40) minimize trauma to patient's vasculature by including a reduced diameter distal end portion (80) configured to expand from an unexpanded configuration in which the central lumen (42) of the expandable sheath (40) along the distal end portion (80) has a first diameter (D1) to an expanded configuration in which the central lumen (42) along the distal end portion (80) has a second diameter (D2) that is larger than the first diameter (D1).

Description

PRE-SHAPED AND ATRAUMATIC TIPS OF EXPANDABLE SHEATHSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 676,977, filed July 30, 2024, which is incorporated by reference in its entirety for all purposes.TECHNICAL FIELD

[0002] The present application is directed to an expandable sheath and introducer 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 patient’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] Percutaneous interventional medical procedures utilize the large blood vessels of the body to reach target destinations rather than surgically opening a target site. There are many types of diseases or states that can be treated via interventional methods including coronary blockages, valve replacements (TAVR) and brain aneurysms. These techniques involve using wires, catheters, balloons, electrodes and other thin devices to travel down the length of the blood vessels from the access site to the target site. The devices have a proximal end which the clinician controls outside of the body and a distal end inside the body, which is responsible for treating the disease state. Percutaneous interventional procedures offer several advantages over open surgical techniques. First, they require smaller incision sites, which reduces scarring and bleeding as well as infection risk. Procedures are also less traumatic to the tissue, so recovery times are reduced. Finally, interventional techniques can usually be performed much faster, and with fewer clinicians participating in the procedure, so overall costs are lowered. In some cases, the need for anesthesia is also eliminated, further speeding up the recovery process and reducing risk.

[0005] A single procedure typically uses several different guidewires, catheters, and balloons to achieve the desired effect. One at a time, each tool is inserted and then removed from the access site sequentially. For example, a guidewire is used to track to the correct location within the body. Next a balloon may be used to dilate a section of narrowed blood vessel. Last, an implant may be delivered to the target site. Because catheters are frequently inserted and removed, introducer sheaths are used to protect the local anatomy and simplify the procedure.

[0006] An introducer sheath can be used to safely introduce a delivery apparatus into a patient’s vasculature (for example, the femoral artery). Introducer sheaths are conduits that seal onto the access site blood vessel to reduce bleeding and trauma to the vessel caused by catheters with rough edges. 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. Once the introducer sheath is positioned within the vasculature, the shaft of the delivery apparatus is advanced through the sheath and into the vasculature, carrying the prosthetic device. Expandable introducer sheaths, formed of highly elastomeric materials, allow for the dilating of the vessel to be performed by the passing prosthetic device.

[0007] One method to reduce push forces through the blood vessel and minimize vessel trauma is to provide a sheath and introducer with as minimum a diameter as possible or with a distal tapering end. However, very small diameter sheaths present challenges of strength and durability. For example, a very small diameter sheath may have lower push force through the vessel, but it may be more likely to tear or expand in a non-reversible manner during insertion into the patient’s vasculature in response to the required push forces for sheath placement and / or after as the prosthetic valve is passed therethrough, which increases risk of trauma to the vessel.

[0008] Some sheaths are provided with a tapered distal end. However, a sheath with a significant distal taper may be more likely to tear or damage the vessel wall during device insertion as the tapered portion risks catching on the patient’s vasculature. In addition, the taper may catch on the vessel wall during placement, inadvertently tearing or expanding the distal tip of the sheath in a non-reversible manner prior to prosthetic device delivery. In some implementations, the layers of the sheath are folded over themselves to form the tapered distal end of the expandable sheath. The folded distal end is configured to unfold and expand when the delivery system and / or prosthetic valve is advanced therethrough. In such cases, the tip may catch on the vessel wallduring placement, inadvertently tear or expand prior to prosthetic device delivery or expand in a non-rcvcrsiblc manner, risking snagging on components of the delivery system, introducer, dilator, or prosthetic device as they are provided to and / or withdrawn from the treatment site. Additionally, sheaths with folded, layered, distal tips require higher push forces to advance the medical device through the folded tip increasing the risk of a tear and non-uniform expansion of the distal tip.

[0009] Accordingly, there remains a need for improvements to the devices, systems and methods of introducing and dilating sheaths, for example by reducing the likelihood of damage to the sheath, unwanted expansion in the sheath, and increasing the uniformity of sheath expansion.SUMMARY

[0010] Aspects of the present expandable sheath and introducer system minimize trauma to the vessel and damage to the sheath and prosthetic device by reducing the push forces through the sheath and increasing the uniformity of sheath distal tip expansion. Aspects ensure that the blood vessel is not damaged during efforts to advance the sheath or during local sheath expansion when a prosthetic device is advanced therethrough. Additional aspects of the present sheath minimize trauma by allowing for a sheath with an initially unexpanded distal tip configuration, which can move to an expanded configuration as the prosthetic device is advanced therethrough.Furthermore, certain implementations can reduce the risk of longitudinal or radial vessel tear as lower push force is required.

[0011] In one of its basic configurations, the present disclosure provides an expandable sheath with reduced diameter distal end portion. This basic configuration can preferably be provided with any one or more of the features described elsewhere herein, in particular with those of the implementations described hereafter. However, it should be understood that the basic configuration can preferably 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 implementations described hereafter.

[0012] In some implementations, the present disclosure provides a sheath system for deploying a medical device.

[0013] In some implementations, the sheath system includes an expandable sheath having a central lumen extending therethrough.

[0014] In some implementations, the expandable sheath includes a distal end portion having an uncxpandcd outer diameter less than an uncxpandcd outer diameter of a body portion of the sheath.

[0015] In some implementations, the present disclosure provides a sheath system for deploying a medical device. In some implementations, the sheath system includes: an expandable sheath having a central lumen extending therethrough. In some implementations, the expandable sheath includes a first polymeric layer and a braided layer radially outward of the first polymeric layer, the braided layer including a plurality of filaments braided together. In some implementations, the expandable sheath includes a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first polymeric layer and the second polymeric layer.

[0016] In some implementations, at least a portion of the expandable sheath is configured to locally expand from an unexpanded configuration in the which the central lumen has a first diameter to an expanded configuration in which the central lumen has a second diameter that is larger than the first diameter, and then locally contract at least partially back to the unexpanded configuration.

[0017] In some implementations, the expandable sheath includes a distal end portion configured to locally expand from an unexpanded configuration in the which the central lumen of the expandable sheath along the distal end portion has a first diameter to an expanded configuration in which the central lumen along the distal end portion has a second diameter that is larger than the first diameter.

[0018] In some implementations, the present disclosure provides a method of delivering a medical device into a blood vessel of a patient. In some implementations, the method includes inserting an expandable sheath at least partially into the blood vessel of the patient.

[0019] In some implementations, the method includes introducing a medical device into a proximal end of a central lumen of the sheath.

[0020] In some implementations, the method includes advancing the medical device through the expandable sheath.

[0021] In some implementations, the method includes advancing the medical device through a distal end portion of the expandable sheath causing the distal end portion to locally expand from an unexpanded configuration to an expanded configuration.

[0022] In some implementations, the method includes advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

[0023] In some implementations, the present disclosure provides a method of delivering a medical device into a blood vessel of a patient.

[0024] In some implementations, the method includes inserting an expandable sheath at least partially into the blood vessel of the patient. In some implementations, the expandable sheath having a central lumen extending therethrough and a distal end portion, the expandable sheath including: a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer including a plurality of filaments braided together; and a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first and second polymeric layers.

[0025] In some implementations, the method includes introducing a medical device into a proximal end of the central lumen of the sheath.

[0026] In some implementations, the method includes advancing the medical device through the expandable sheath.

[0027] In some implementations, the method includes advancing the medical device through the distal end portion causing the distal end portion to locally expand from an unexpanded configuration in the which the distal end portion has a first diameter to an expanded configuration in which the distal end portion has a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration. In some implementations, the method includes advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

[0028] In some implementations, the present disclosure provides a method of expanding an expandable sheath.

[0029] In some implementations, the method includes providing an expandable sheath.

[0030] In some implementations, the method includes introducing a medical device into a central lumen of the sheath.

[0031] In some implementations, the method includes advancing the medical device through the expandable sheath.

[0032] In some implementations, the method includes advancing the medical device through a distal end portion of the sheath, causing the distal end portion to locally expand from anunexpanded configuration in the which the distal end portion has a first diameter to an expanded configuration in which the distal end portion has a second, larger, diameter.

[0033] In some implementations, the method includes advancing the medical device beyond a distal opening in the expandable sheath.

[0034] In some implementations, the present disclosure provides a method of expanding an expandable sheath. In some implementations, the method includes providing an expandable sheath having a central lumen extending therethrough and a distal end portion, the expandable sheath including: a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer including a plurality of filaments braided together; and a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first and second polymeric layers.

[0035] In some implementations, the method includes introducing a medical device into a proximal end of the central lumen of the sheath.

[0036] In some implementations, the method includes advancing the medical device through the expandable sheath.

[0037] In some implementations, the method includes advancing the medical device through the distal end portion causing the distal end portion to locally expand from an unexpanded configuration in the which the distal end portion has a first diameter to an expanded configuration in which the distal end portion has a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

[0038] In some implementations, the method includes advancing the medical device beyond a distal opening in the expandable sheath.BRIEF DESCRIPTION OF DRAWINGS

[0039] FIG. 1 is a side view of an exemplary delivery apparatus for a cardiovascular prosthetic device.

[0040] FIG. 2 is a side view of an exemplary introducer device assembly.

[0041] FIG. 3 is a side view of an expandable sheath that can be used in combination with the introducer device assembly of FIG. 2.

[0042] FIG. 4 is a side cross-sectional view of a portion of the expandable sheath of FIG. 3.

[0043] FIG. 5 is a magnified side view of a portion of the expandable sheath of FIG. 3.

[0044] 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.

[0045] FIG. 6B is a magnified side view of a portion of the braided layer of the sheath of FIG. 3.

[0046] 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.

[0047] FIG. 8 is a side cross-sectional view of a distal portion of an example expandable sheath in an unexpanded configuration.

[0048] FIG. 9 is a side cross-sectional view of a distal portion of the example expandable sheath of FIG. 8 in an expanded configuration.

[0049] FIG. 10 is a side cross-sectional view of a distal portion of an example expandable sheath in an unexpanded configuration.

[0050] FIG. 11 is a cross-sectional view of the expandable sheath of FIG. 10 in an unexpanded configuration along section line A-A.

[0051] FIG. 12 is a cross-sectional view of the expandable sheath of FIG. 10 in an expanded configuration along section line A-A.

[0052] FIG. 13 is a side cross-sectional view of a distal portion of an example expandable sheath in a folded configuration.

[0053] FIG. 14 is a side cross-sectional view of a distal portion of the example expandable sheath of FIG. 13 in an unfolded configuration.

[0054] FIG. 15 is a partial side view of an example mandrel.

[0055] FIG. 16 is a partial side view of the example mandrel of FIG. 15 with an example sheath mounted thereon.

[0056] FIG. 17 is a side cross-sectional view of a distal portion of an example expandable sheath in an unexpanded configuration.

[0057] FIG. 18 is a side cross-sectional view of a distal portion of the example expandable sheath of FIG. 17 in an expanded configuration.

[0058] FIG. 19 is a side perspective view of an example ring in an unexpanded configuration.

[0059] FIG. 20 is a side perspective view of the example ring of FIG. 19 in an unexpanded configuration with the release pin disengaged.

[0060] FIG. 21 is a side perspective view of the example ring of FIG. 19 in an expanded configuration.DETAILED DESCRIPTION

[0061] The following description of certain implementations 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.

[0062] For purposes of this description, certain aspects, advantages, and novel features of the aspects 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 various disclosed aspects, 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 the disclosed methods, systems, and apparatus require that any one or more specific advantages be present or problems be solved.

[0063] Features, integers, characteristics, compounds, chemical moieties, or groups described in conjunction with a particular aspect or implementation of the present disclosure are to be understood to be applicable to any other aspect or implementation 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.

[0064] 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 hereinby 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.

[0065] 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.

[0066] "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.

[0067] The terms “proximal” and “distal” as used herein refer to regions of a sheath, catheter, or delivery assembly. “Proximal” means that region closest to handle of the device, while “distal” means that region farthest away from the handle of the device.

[0068] “Axially” or “axial” as used herein refers to a direction along the longitudinal axis of the sheath.

[0069] Throughout the description and claims of this specification, the word "comprise" and variations of the word, such as "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 "an example of" and is not intended to convey an indication of a preferred or ideal aspect. "Such as" is not used in a restrictive sense, but for explanatory purposes.

[0070] The expandable introducer sheaths and related componentry described herein can be used to deliver a prosthetic device through a patient’s 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 aspects, theexpandable 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.

[0071] 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. PCT7US 2021 / 031275, 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 “Low temperature 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,” and U.S. Provisional Application No. 63 / 502,907, entitled “Lead Screw Driven Sheath Dilator,” the disclosures of which are herein incorporated by reference.

[0072] FIG. 1 illustrates an exemplary sheath 40 in use with a representative delivery apparatus 10, such as a prosthetic heart valve or other prosthetic implant, to a patient. The delivery apparatus 10 illustrated can generally include a steerable guide catheter 14 (also referred to as aflex catheter) 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 patient's body.

[0073] As described in more detail herein, the sheath 40 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 patient, such that the distal end of the sheath 40 is inserted into the vessel. The sheath 40 includes a hemostasis valve and / or sealing features at the proximal end of the sheath 40, for example, in the sheath hub 24, that provide hemostasis and prevents blood leakage from the patient through the sheath 40. The sheath 40, including an introducer 100, is advanced into the patient’s vasculature. Once positioned the introducer 100 is removed and the guide catheter 14 is inserted into / through the sheath 40, and the prosthetic heart valve (prosthetic device 12) then be delivered and implanted within patient. The guide catheter 14 includes a handle portion 18 and an elongated guide tube or shaft extending from the handle portion 18.

[0074] The prosthetic heart valve (prosthetic device 12) can be delivered into a patient’s body in a radially compressed configuration and radially expanded to a radially expanded configuration at the desired deployment site. In the illustrated implementation, the prosthetic heart valve (prosthetic device 12) is a plastically expandable prosthetic valve that is delivered into the patient’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 at the deployment site by inflating the balloon (or by actuating another type of expansion device of the delivery apparatus). 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. 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 aradially compressed configuration by a sheath or other component of the delivery apparatus and sclf-cxpands to a radially expanded configuration when released by the sheath or other component of the delivery apparatus. Further details regarding a self-expandable 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. In still some implementations, 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. In still some implementations, a prosthetic valve can incorporate two or more of the above-described 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.

[0075] 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 apparatus 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 mean anything - prosthetic or not - that is delivered to a site within a body. A diagnostic device, for example, may be an implantable.

[0076] FIG. 2 illustrates an example of an introducer device assembly 20. The introducer device assembly 20 may include the sheath 40 and an introducer 100. The introducer 100 may be positioned within a central lumen 42 (indicated in FIG. 4) of the sheath 40, 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.

[0077] The sheath 40 and introducer 100 are shown in an insertion configuration, for insertion together into the patient's vasculature. Upon insertion into the patient's vasculature, theintroducer 100 may be withdrawn longitudinally from the sheath 40, leaving the sheath 40 within the patient's vasculature. Features of the sheath 40 and the introducer 100 individually arc discussed below, as well as the operation of the sheath 40 and introducer 100 together.

[0078] The sheath 40 comprises an elongated body that may have a cylindrical shape. The sheath 40 has a distal end 43 and a proximal end 44, and a length LI (see FIG. 3) extending from the distal end 43 to the proximal end 44. The sheath 40 is configured to be inserted into a patient's vasculature. The sheath 40 may optionally comprise an introducer sheath that is used to introduce a delivery apparatus into the patient's vasculature.

[0079] The vasculature may comprise the blood vessels of the patient's body which may include the femoral artery or other vessels of the patient'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 patient to pass therethrough by itself. Also, the vasculature may be too fragile to receive the delivery apparatus without use of an introducer sheath.

[0080] The sheath 40 accordingly may optionally be inserted into the patient’s vasculature prior to the delivery apparatus being introduced, to provide an entry way or guide path for the delivery apparatus 10 to introduce the delivery apparatus into the patient’s vasculature. After the sheath 40 is inserted, the sheath 40 may remain positioned within and surrounded by the patient’s vasculature. The delivery apparatus 10 may then be passed through the lumen of the sheath 40 for introduction into the patient’s body. The sheath 40 may remain in the vasculature until a desired time to remove the sheath 40.

[0081] The sheath 40 may be inserted into the vasculature percutaneously or a portion of the patient’s body may be surgically opened for the sheath 40 to access the vasculature. The delivery apparatus 10 passes through the lumen of the sheath 40 to reach a desired position in the patient's body. As shown in FIG. 1, the delivery apparatus 10 may pass through an opening at the proximal end of the sheath 40 for passage through the central lumen 42 of the sheath 40 and the vasculature of the patient. For example, in some implementations, the delivery apparatus 10 passes through an opening at the proximal end of the sheath 40 provided at the control housing 22 shown in FIG. 2.

[0082] The delivery apparatus and the assemblies disclosed herein may be used in transcatheter aortic valve implantation (TAVI). The delivery apparatus and the systems disclosed herein may be utilized for transarterial access, including transfemoral access, to a patient’s heart.

[0083] The sheath 40 may optionally include a strain relief portion 46 at the proximal end 44 of the sheath 40. The strain relief portion 46 may be sized larger than a proximate portion of the sheath 40 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 40 and the vasculature. The strain relief portion 46 provides a transition between the larger diameter proximal opening of the sheath 40 and the smaller diameter distal portion / opening of the sheath 40 as the medical device and / or introducer 100 are inserted into the central lumen 42 of the sheath 40. In some implementations, a seal 48 is optionally positioned along the length of the sheath 40 to further prevent blood or other fluid flow from passing around the sheath 40 toward and out of the proximal end 44 of the sheath 40.

[0084] FIG. 3 illustrates a side view of an exemplary expandable sheath 40 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 44 of the sheath 40. The sheath hub 24 may optionally include an internal chamber for the delivery apparatus 10 to be passed through to be delivered to the patient's vasculature. The sheath hub 24 may be configured to remain external to the patient's vasculature when the sheath 40 is inserted therein and may be configured to remain external to the patient's skin for a percutaneous implantation of the sheath 40. The sheath hub 24 may be configured for a user (such as a surgeon) to grip to manipulate the sheath 40.

[0085] The sheath hub 24 may optionally comprise a cylindrical body and may include a coupler 29 for coupling to another housing or component of the system. The sheath hub 24 may optionally include a fluid port 26 for passing fluid such as blood to or from the patient'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.

[0086] In some implementations, the introducer sheath need not include a sheath hub 24. For example, the sheath 40 can be an integral part of a component of the delivery apparatus 10, such as the guide catheter. For example, the sheath 40 can extend from the handle portion 18 of the guide catheter. Additional implementations 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.

[0087] FIGS. 4 and 5 illustrate a cross-sectional view and a side view, respectively, of a portion of the expandable sheath 40. As shown in FIG. 5, the sheath 40 can have a natural, unexpanded outer diameter DI. In certain implementations, the expandable sheath 40 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 40 can include a first layer / inner layer 52 (also referred to as an inner layer), 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 42 extending along a central axis Cl. In some implementations, the sheath 40 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.

[0088] Referring to FIG. 5, when the sheath 40 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.

[0089] In some implementations, the inner layer 52 and / or the outer layer 58 can comprise a relatively thin layer of polymeric material. For example, in some implementations, 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 0.25 mm. In some implementations, 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.

[0090] In some implementations, the inner layer 52 and / or the outer layer 58 can comprise a lubricious, low-friction, and / or relatively non-elastic material. In some implementations, 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 through the central lumen 42. 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 implementations of a sheath 40 can include a lubricious liner on the inner surface of the inner layer 52. Implementations 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.

[0091] Additionally, some implementations of the sheath 40 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 40 into a patient’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 NV, Heerlen, the Netherlands), as well as other hydrophilic coatings (for example, PTFE, polyethylene, polyvinylidene fluoride), are also suitable for use with the sheath 40. Such hydrophilic coatings may also be optionally included on the inner surface of the inner layer 52 to reduce friction between the sheath and the delivery system, thereby facilitating the use and improving safety. In some implementations, 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.

[0092] In some implementations, the second layer / braided layer 54 can include a braided material. FIGS. 6A and 6B illustrate the sheath 40 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 a plurality 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 60A and60B can be braided together in a biaxial braid such that filaments 60A oriented along axis A form an angle 0 with the filaments 60B oriented along axis B. In certain implementations, the angle 9 can be from 5° to 70°, 10° to 60°, 10° to 50°, or 10° to 45°. In the illustrated implementations, the angle 9 is 45°. In some implementations, 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.

[0093] The braided layer 54 can extend along substantially the entire length LI of the sheath 40, or alternatively, can extend only along a portion of the length of the sheath 40. In some implementations, 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 certain implementations, 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 implementations, 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 implementation, filaments 60 having a flat cross-section can have dimensions of 0.1 mm x 0.2 mm. However, other geometries and sizes are also suitable for certain implementations. If a braided wire is used, the braid density can be varied. Some implementations 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 implementations, 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.

[0094] The third layer / elastic layer 56 can be a resilient, elastic layer (also referred to as an elastic material layer). In certain implementations, 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 Cl of the sheath 40) when the sheath 40 expands beyond its natural diameter by passage of the delivery apparatus through the sheath 40. Stated differently, the elastic layer 56 can be configured to apply encircling pressure to the layers of the sheath 40 beneath the elastic layer 56 to counteract expansion of the sheath 40. The radially inwardly directed force is sufficient to cause the sheath 40 to collapse radially back to its unexpanded state after the delivery apparatus is passed through the sheath 40.

[0095] In the illustrated implementations, 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 40, 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.

[0096] In some implementations, the elastic layer 56 can comprise an elastomeric material having a modulus of elasticity of 200 MPa or less. In some implementations, 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 40 may also include an optional elastomeric or heat-shrink tubing layer around the outer layer 58. implementations 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 implementations, the elastic layer 56 can also be radially outward of the polymeric outer layer 58.

[0097] In some implementations, one or both of the inner layer 52 and / or the outer layer 58 can be configured to resist axial shortening of the sheath 40 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 and the inner surface of the sheath such that the length LI remains substantially constant as the sheath expands and contracts radially. As used herein with reference to the length LI of the sheath, the term “substantially constant” means that the length LI of the sheath increases by not more than 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 60A 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 expands and contracts. This, in combination with the longitudinal ridges 62 (folds) in the innerlayer 52 and outer layer 58, can allow the central lumen 42 to expand as a prosthetic device 12 is advanced through it.

[0098] In some implementations, 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 certain implementations, 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 certain implementations, 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 9 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.

[0099] FIG. 7 illustrates radial expansion of the sheath 40 as a prosthetic heart valve 12 is passed through the sheath 40 in the direction of arrow A (for example, distally). As the prosthetic heart valve 12 is advanced through the sheath 40, the sheath 40 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 40, the prosthetic device 12 can apply longitudinal force to the sheath 40 in the direction of motion by virtue of the frictional contact between the prosthetic device 12 and the inner surface of the sheath 40. 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 40 remains constant, or substantially constant. This can reduce or prevent the braided layer 54 from lengthening, and thereby constricting the central lumen 42.

[0100] Meanwhile, in some implementations, the angle 0 between the filaments 60A and 60B can increase as the sheath 40 expands to the second diameter D2 to accommodate the prostheticdevice 12. This can cause the braided layer 54 to foreshorten. However, because the filaments 60 arc 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. 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 40 can resiliently expand from its natural diameter D 1 to a second diameter D2 that is larger than the diameter DI as a prosthetic device 12 is advanced through the sheath 40, without lengthening, and without constricting. Thus, the force required to push the prosthetic device 12 through the sheath 40 is significantly reduced.

[0101] Additionally, because of the radial force applied by the elastic layer 56, the radial expansion of the sheath 40 can be localized to the specific portion of the sheath 40 occupied by the prosthetic device 12. For example, with reference to FIG. 7, as the prosthetic heart valve 12 moves distally through the sheath 40, the portion of the sheath 40 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 40 is reduced, causing the ridges 62 and the valleys 64 to reform. This can reduce the size of the sheath 40 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 40 is inserted, along with the surrounding tissue, because only the portion of the sheath 40 occupied by the prosthetic device 12 expands beyond the sheath’s natural diameter and the sheath 40 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.

[0102] In addition to the advantages above, the expandable sheath 40 examples described herein can provide surprisingly superior performance relative to known introducer sheaths. For example, it is possible to use a sheath 40 configured as described herein to deliver a prosthetic device having a diameter that is two times larger, 2.5 times larger, or even three times larger than the natural outer diameter of the sheath 40. For instance, in one implementation, a crimped prosthetic heart valve having a diameter of 7.2 mm was successfully advanced through a sheathconfigured as described above and having a natural outer diameter of 3.7 mm. As the prosthetic valve was advanced through the sheath 40, the outer diameter of the portion of the sheath 40 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 40 through the sheath 40, during which the outer diameter of the sheath 40 resiliently increased by 216%. In another implementations, a sheath 40 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.

[0103] As illustrated in FIGS. 8-20, in some implementations, the sheath 40 has a tapered or otherwise reduced diameter distal end portion 80 that helps to reduce trauma or damage to the blood vessel as the sheath 40 is advanced to the treatment site. The distal end portion 80 extends along a length (L) of the sheath 40 from the distal end 43 of the sheath 40 in a direction towards the proximal end 44. Additionally, in some implementations, the tapered / reduced diameter distal end portion 80 provides an outer surface of the sheath 40 having a decreasing taper that reduces push force as the sheath 40 is advanced through the patient’s blood vessel and to the treatment site.

[0104] In some implementations, the tapered or reduced diameter distal end portion 80 of the sheath 40 is provided by maintaining (actively or passively) the distal end 43 of the sheath 40 in a non-expanded and / or otherwise contracted configuration. As described herein, and illustrated in FIGS. 8-20, in the non-expanded and / or contracted configuration, the distal end 43 and / or distal end portion 80 of the sheath 40 has a diameter less than the diameter of the elongated body portion 49 of the sheath 40.

[0105] As described in more detail herein, like the elongated body portion 49 of the sheath 40, the distal end portion 80 is movable between the unexpanded / contracted configuration and an expanded configuration. In some implementations, the distal end portion 80 of the sheath moves between the unexpanded and expanded configuration as the prosthetic device 12 and / or delivery apparatus is advanced therethrough. In the unexpanded configuration, the central lumen 42 of the sheath 40 along the distal end portion 80 has a first diameter, and in the expanded configuration the central lumen 42 along the distal end portion 80 has a second, larger, diameter. As described in more detail herein, in some implementations, once positioned at the treatment site, the distal end portion 80 of the sheath 40 can expand due to the outwardly directed radial force exerted onthe central lumen 42 of the expandable sheath 40 by a medical device (prosthetic device 12) passing therethrough.

[0106] FIGS. 8 and 9 illustrate a partial cross-sectional view of the distal end portion 80 of an example sheath 40. FIG. 8 shows the distal end portion 80 in an unexpanded configuration, and FIG. 9 shows the distal end portion 80 in an expanded configuration as the prosthetic device 12 and corresponding delivery system pass therethrough. FIGS. 8 and 9 illustrate a corresponding change in the diameter of the central lumen 42 and outer diameter of the sheath 40, as the sheath 40 moves between the unexpanded and expanded configuration. As illustrated in FIGS. 8 and 9, in the unexpanded configuration, the outer diameter of the distal end portion 80 is less than the outer diameter of the distal end portion 80 in the expanded configuration. In the expanded configuration, shown in FIG. 9, the inner and / or outer diameter of the distal end portion 80 corresponds with the corresponding inner and / or outer diameter of the elongated body portion 49 of the sheath 40.

[0107] As shown in FIG. 8, in the unexpanded configuration, the inner diameter of the distal end portion 80 decreases toward the distal end 43 of the sheath 40. For example, in some implementations, the diameter of the central lumen 42 of the sheath 40 decreases from the proximal end 44 and / or along elongated body portion 49 to the distal end 42 of the sheath 40. For example, as illustrated in FIG. 8, the unexpanded diameter (DI) of the central lumen 42 at the distal opening of the distal end portion 80 is less than the unexpanded diameter (D2) of the central lumen 42 along the elongated body portion 49. In some implementations, the unexpanded diameter of the central lumen 42 along the distal end portion 80 defines a continuous decreasing taper from the elongated body portion 49 to the distal end 43 of the sheath 40. In implementations, as illustrated in FIG. 8, the unexpanded diameter along the distal end portion 80 has a portion of increased diameter (D3) with respect to the diameter (D2) of the elongated body portion 49. For example, in some implementations as shown in FIG. 8, the central lumen 42 along the distal end portion 80 defines a concave surface extending from the inner surface of the central lumen 42 away from the longitudinal axis of the sheath 40.

[0108] In some implementations, the distal end portion 80 of the expandable sheath 40 is biased in the unexpanded configuration. As such, in some implementations, the distal end portion 80 is configured to contract at least partially back to the unexpanded configuration as the medical device or other outwardly directed radial force passes through the distal end portion 80.Similarly, in some implementations as described herein, the expandable sheath 40 is biased toward the uncxpandcd configuration.

[0109] In some implementations as described herein, the reduced diameter distal end portion 80 of the sheath 40 is formed from plurality of longitudinally-extending folds. The longitudinally- extending folds are biased toward the folded / unexpanded configuration such that as a medical device (or other outwardly directed radial) is passed through the expandable sheath 40, the plurality of longitudinally-extending folds at least partially unfold radially expanding the sheath 40 to / toward the expanded configuration. As the medical device passes (or upon removal of any other outwardly directed radial force on the central lumen 42 of the sheath 40), the longitudinally-extending folds return back toward the folded configuration causing the sheath 40 and the distal end portion 80 to return to / toward the unexpanded configuration.

[0110] In some implementations, as described herein, the sheath 40 optionally includes the resilient elastic layer 56 configured to apply an inward directed radial force to the underlying layers of the sheath 40, including the distal end portion 80. As such, when a medical device is passed through the expandable sheath 40, the inward directed radial force of the elastic layer 56 causes the expandable sheath 40 and distal end portion 80 to resiliently return to / toward the unexpanded configuration upon passage of the medical device (or removal of any other outwardly directed radial force on the central lumen 42 of the sheath 40).

[0111] In some implementations, the braided layer 54 is used to form the reduced diameter distal end portion 80 of the sheath 40. For example, as illustrated in FIGS. 8 and 9, in some implementations braided layer 54 is provided between the first polymeric layer 52 and the second polymeric layer 58. In some implementations, the second polymeric layer 58 is optionally bonded to the first polymeric layer 52 such that the braided layer 54 is encapsulated between the first polymeric layer 52 and the second polymeric layer 58.

[0112] In some implementations, as shown in FIGS. 8 and 9, the braided layer 54 extends along the distal end portion 80 of the expandable sheath 40, helping to form the reduced diameter structure / shape of the distal end portion 80 of the sheath 40 as described herein. In some implementations, the distal end portion 55 of the braided layer 54 defines a reduced diameter portion of the braided layer 54 that helps to form the reduced diameter shape of the distal end portion 80 of the sheath 40. The distal end portion 55 extends along a length of the braided layer 54 extending from the distal end 43 of the braided layer 54 towards the proximal end of thebraided layer 54. Tn some implementations, the length of the distal end portion 55 along the braided layer braided layer 54 corresponds with the length (L) of the distal end portion 80 along the sheath 40.

[0113] The distal end portion 55 of the braided layer 54 is configured to locally expand from an unexpanded configuration in the which the braided layer 54 has a first diameter, as illustrated in FIG. 8, to an expanded configuration in which the braided layer 54 has a second, larger, diameter, as illustrated in FIG. 9, and then locally contract at least partially back to / toward the unexpanded configuration. For example, as illustrated in FIG. 9, the distal end portion 55 of the braided layer 54 expands due to the outwardly directed radial force exerted on the central lumen 42 of the expandable sheath 40 as the medical device / delivery system passes through the distal end portion 80 of the expandable sheath 40, and then toward the unexpanded, reduced diameter, configuration as the medical passes through the distal end portion 80 / distal end portion 55.

[0114] In some implementations, the distal end portion 55 of the braided layer 54 defines a decreasing tapered shape in cross-section. For example, in some implementations, in the unexpanded configuration, the distal end portion 55 has a decreasing inwardly tapered shape. The inwardly tapered configuration of the distal end portion 55 of the braided layer 54 helps to define the corresponding inward / decreasing tapered shape of the distal end portion 80 of the sheath 40. In some implementations, the tapered portion of the distal end portion 55 is defined as a decreasing tapered extending from a body portion of the braided layer 54 (corresponding to the elongated body portion 49 of the sheath 40) toward the distal end 57 of the braided layer 54 / distal end 43 of the sheath 40.

[0115] In some implementations, the distal end portion 55 of the braided layer 54 includes a curved portion 59. The curved portion 59 of the distal end portion 55 can extend radially in the direction towards or away from the longitudinal center line of the braided layer 54. For example, in some implementations, as illustrated in FIG. 8 the distal end portion 55 includes a curved portion 59 defining a concave surface extending away from the longitudinal centerline of the braided layer braided layer 54. The curved portion 59 can extend along the entire length of the distal end portion 55 and / or along a portion of the length of the distal end portion 55.

[0116] In some implementations, the distal end portion 55 of the braided layer 54 is formed from a shape-memory material. An example shape-memory material includes Nitinol. In some implementations, the distal end portion 55 is shape-set to assume an outwardly curvedconfiguration as illustrated in FIG. 8. In some implementations, the shape-memory material of the distal end portion 55 is shape-set to assume an inwardly tapered configuration. For example, in some implementations, the distal end portion 55 of the braided layer 54 is shape-set to form pleat-pattern or otherwise folded-pattern forming the decreasingly tapered shape of the distal end portion 55. In some implementations, the pleat-pattern or folded-pattern can form the decreasing tapered shape extending from the main body portion of the braided layer 54 toward the distal end 57 the braided layer 54, and toward the distal end 43 of the expandable sheath 40.

[0117] In some implementations, the braided layer 54 is not included along the distal end portion 80. For example, as illustrated in FIGS. 10-16, the material and / or structure of the distal end portion 80 is used to form the reduced diameter shape of the distal end of the sheath 40, without the including the braided layer 54 along the distal end portion 80. For example, as provided in FIGS. 10-16, in some implementations, distal end portion 80 is formed by various layers of the sheath 40 including the first polymeric layer 52 and / or the second polymeric layer 58, while not including the braided layer 54. As shown in FIG. 10, the first polymeric layer 52 and the second polymeric layer 58 extend beyond the distal end 57 of the braided layer 54.

[0118] As illustrated in FIGS. 10-16, in some implementations, the first polymeric layer 52 and the second polymeric layer 58 extend along the distal end portion 80 to form the distal tip 82 of the sheath 40. Similar to the distal end portion 80 of the example sheath 40 illustrated in FIG. 8, the distal end portion 80 / distal tip 82 of the example sheath 40 illustrated in FIG. 10 has a diameter less than the diameter of the elongated body portion 49 of the sheath 40, reducing push forces needed to advance the sheath 40 into and through the patient’s vasculature and reducing the likelihood of damage to the blood vessel. In some implementations, the distal tip 82 defines a tubular- shaped portion 84 extending distally from the braided layer 54. As illustrated in FIG. 10, in some implementations, the tubular- shaped portion 84 has a constant diameter along all or a portion of the length (L) of the distal end portion 80. In some implementations, the distal end portion 80 includes a tapered portion extending between the larger-diameter elongated body portion 49 of the sheath 40 and the smaller-diameter tubular - shaped portion 84.

[0119] As described herein, in some implementation, the distal end portion 80, including the tubular- shaped portion 84, is configured to locally expand from an unexpanded configuration in the which the each of the distal end portion 80 and distal tip 82 / tubular-shaped portion 84 have a first diameter to an expanded configuration in which each of the distal end portion 80 and distaltip 82 / tubular-shaped portion 84 have a second diameter that is larger than the first diameter, and then locally contract at least partially back toward the unexpanded configuration. As described herein, in some implementations, the distal tip 82 / tubular-shaped portion 84 of the distal end portion 80 are configured to move between the unexpanded and expanded configuration due to the outwardly directed radial force exerted on the central lumen 42 of the expandable sheath 40 by a medical device / delivery system passing therethrough (or other outwardly directed radial force on the central lumen 42 of the sheath 40).

[0120] Similar to the sheath 40 described herein, in some implementations the distal end portion 80 and the distal tip 82 / tubular-shaped portion 84 are biased in the unexpanded configuration. In some implementations, the distal tip 82 / tubular-shaped portion 84 and / or the distal end portion 80 of the expandable sheath 40 is configured to elastically expand to / toward the expanded configuration and return to the unexpanded configuration. In some implementations, the distal tip 82 / tubular-shaped portion 84 and / or the distal end portion 80 of the expandable sheath 40 is optionally configured to tear and / or split as the distal tip 82 / distal end portion 80 expands from the unexpanded configuration to the expanded configuration.

[0121] In some implementations, as illustrated in FIGS. 10-12, the sheath 40 includes can include an elastic band 130 constricting or otherwise retaining at least a portion of the distal end portion 80 of the sheath 40, thereby forming the reduced diameter shape of the distal end of the sheath 40.

[0122] In some implementations, as illustrated in FIGS. 10-12, the elastic band 130 can be located along the tubular- shaped portion 84 of the distal end portion 80. The elastic band 130 is configured expand and contract between an unexpanded configuration and an expanded configuration. For example, in some implementations, the elastic band 130 is configured to locally expand from an unexpanded configuration in the which the elastic band 130 has a first diameter (illustrated in FIG. 11), to an expanded configuration (FIG. 12) in which the elastic band 130 has a second diameter that is larger than the first diameter, and then locally contract at least partially back to the unexpanded configuration. In some implementations, the elastic band 130 is configured to move from the unexpanded and expanded configuration due to the outwardly directed radial force exerted on the central lumen 42 of the expandable sheath 40 by a medical device / delivery system passing therethrough. In some implementations, the elastic band 130 is biased in the unexpanded configuration.

[0123] FIG. 10 is a partial side cross section view of the distal end of the sheath 40 showing the distal tip 82 / distal end portion 80 in an expanded configuration. FIG. 11 is a cross section view of the distal tip 82 of the sheath 40 a long section line A-A in FIG. 10, with the distal tip 82 in the unexpanded configuration. FIG. 14 is a cross section view of the distal tip 82 of the sheath 40 a long section line A-A in FIG. 10, with the distal tip 82 in the expanded configuration. As provided in FIGS. 11 and 12, the central lumen 42 of the distal tip 82 is larger in the expanded configuration (FIG. 12) compared to the central lumen 42 of the distal tip 82 in the unexpanded configuration (FIG. 11). Additionally in some implementation, as illustrated in FIGS. 11 and 12, the wall thickness of the elastic band 130 is thicker in the unexpanded configuration (FIG. 11) compared to the wall thickness of the elastic band 130 in the expanded configuration (FIG. 12).

[0124] As provided in FIG. 11, the elastic band 130 is coupled to the distal tip 82 and / or tubularshaped portion 84 of the expandable sheath 40. In some implementations, embedded between the first polymeric layer 52 and the second polymeric layer 58, such that the elastic band 130 is located radially inward of the first polymeric layer 52 and radially outward of the second polymeric layer 58. In some implementations the elastic band 130 is located radially inward of the first polymeric layer 52 and the second polymeric layer 58. In further implementations the elastic band 130 is located radially outward of both the first polymeric layer 52 and the 2nd polymeric layer 58. In some implementations, the elastic band 130 is coupled to the distal end of the sheath 40 / distal end portion 80.

[0125] In some implementations, the distal end of the sheath 40 is folded inward to form a rounded shape at the distal end 43 of the sheath 40. For example, as illustrated in FIGS. 13 and 14, at least a portion of the distal end portion 80 of the sheath 40 is folded inward into the central lumen 42 of the sheath 40. As illustrated in FIG. 13, the folded edges / folded portion 86 of the distal end portion 80 form a curved and / or rounded end surface at the end of the sheath 40, that helps to reducing push forces needed to advance the sheath 40 into and through the patient’s vasculature and reducing the likelihood of damage to the blood vessel by impact / interference with the distal end of the sheath 40. As shown in FIG. 14, as the prosthetic device 12 is advanced through the central lumen 42 of the sheath 40, the folded portion 86 of the distal end portion 80 unfold axially, and form the elongated distal end portion 80 of the sheath 70.

[0126] In some implementations, as described herein, the first polymeric layer 52 and the second polymeric layer 58 extend beyond the braided layer 54 and along the distal end portion 80 of theexpandable sheath 40, and the braided layer 54 does not extend into the distal end portion 80. As illustrated in FIGS. 13 and 14, the first polymeric layer 52 and the second polymeric extend 58 beyond the distal end portion 80, beyond the braided layer 54 to form a tubular- shaped distal tip 82 of the sheath 40. As described herein, the distal tip 82 is movable between a folded configuration (FIG. 13) and an unfolded configuration (FIG. 14). In the folded configuration, at least a portion of the distal tip 82 (including folded portion 86) is folded back within the central lumen 42 of the expandable sheath 40. In the unfolded configuration, the distal tip 82 (including folded portion 86) unfolds and extends axially in a distal direction along the distal end portion 80.

[0127] As illustrated in FIG. 13, in the folded configuration, the distal end 43 of the expandable sheath 40 positioned within the central lumen 42 of the expandable sheath 40 extending in a direction towards the proximal end 44 of the expandable sheath 40. With the distal tip 82 in the folded configuration, the folded portion 86 of the distal tip 82 provides a rounded end surface 88. As illustrated in FIG. 13, the rounded end surface 88 provides an atraumatic end surface during advancement of the expandable sheath 40 through the vasculature. In some implementations, the distal tip 82 is biased in the folded configuration.

[0128] The distal tip 82 is moved from the folded configuration to the unfolded configuration by the axial movement of the medical device and / or delivery system through the central lumen 42 of the sheath 40. In some implementations, with the distal tip 82 in the folded configuration, as the medical device and / or delivery system is advanced through the central lumen 42 of the sheath 40, the medical device and / or delivery system contacts the distal end 43 of the expandable sheath 40 folded / located within the central lumen 42 of the sheath 40. The axial force of the medical device and / or delivery system on the distal end 43 of the expandable sheath 40 causes the distal tip 82 / folded portion 86 to unfold. In some implementations, as illustrated in FIG. 14, in the unfolded and unexpanded configuration the outer diameter of the distal tip 82 has a diameter less than the outer diameter of the elongated body portion 49 of the sheath 40.

[0129] FIGS. 15 and 16 illustrate various manufacturing stages of forming the distal end portion 80 of the sheath 40. FIG. 15 provides a partial side view of an example mandrel 120 for forming the distal end portion 80 of the sheath 40. FIG. 16 illustrates the sheath 40 received over the mandrel 120. As described herein, in some implementations, the expendable sheath 40 is formedby layering the first polymeric layer 52, the braided layer 54, and the second polymeric layer 58 over the mandrel 120.

[0130] As illustrated in FIG. 15, the mandrel 120 includes an elongated body portion 122 and a tapered distal end portion 124. As illustrated in FIG 16, the elongated body portion 122 of the mandrel 120 has a diameter corresponding to the diameter of the central lumen 42 of the sheath 40. Similarly, the tapered distal end portion 124 of the mandrel 120 has a size and shape corresponding to the size and shape of the distal end portion 80 of the sheath 40. In some implementations, the first polymeric layer 52, the braided layer 54, and the second polymeric layer 58 are layered on to the mandrel 120 such that the first polymeric layer 52 and the second polymeric layer 58 extend beyond the distal end 57 of the braided layer 54. As such the first polymeric layer 52 and the second polymeric layer 58 extend along the tapered distal end portion 124 of the mandrel 120, beyond the braided layer 54.

[0131] In some implementations, the first polymeric layer 52, the braided layer 54, and the second polymeric layer 58 are layered on to the mandrel 120 by spinning around the mandrel 120. For example, the layers can be applied to the mandrel 120 by applying the materials of the first polymeric layer 52, the braided layer 54, and the second polymeric layer 58 to a spinning mandrel 120.

[0132] In some implementations, the first polymeric layer 52 and the second polymeric layer 58 are then coupled together to form the distal end portion 80 while mounted on the mandrel 120. In some implementations, the first polymeric layer 52 and the second polymeric layer 58 can be coupled together by at least one of a mechanical fastener, a chemical fastener and / or a heat process (for example, a reflow process). In some implementations, the various layers of the sheath 40 subjected to a heat process and coupled together while mounted on the mandrel 120. For example, in some implementations, the materials of the first polymeric layer 52 and the second polymeric layer 58 are reflowed together.

[0133] The mandrel 120 is then removed from the central lumen 42 of the expandable sheath 40 with the joined layers (for example, joined first polymeric layer 52 and the second polymeric layer 58) forming the distal end portion 80 of the expandable sheath 40.

[0134] It is contemplated that the sheaths 40 illustrated in FIGS. 9-14 can be formed on a mandrel similar- to the method described above in reference to FIGS. 15 and 16 and mandrel 120. In some implementations, the elastic band 130 is positioned between the first polymeric layer 52and the second polymeric layer 58 during formation of the expandable sheath 40 on the mandrel 120. For example, the clastic band 130 can optionally positioned over the spun first polymeric layer 52 prior to forming the second polymeric layer 58.

[0135] FIGS. 17-21 illustrate an example sheath 40 including an expandable ring 140 provided at the distal end portion 80 of the sheath 80. Similar to the elastic band 130 described in reference to FIGS. 10-12, the ring 140 can be used to constrict or otherwise retaining at least a portion of the distal end portion 80 of the sheath 40, thereby forming the reduced diameter shape of the distal end of the sheath 40. In some implementations, the ring 140 releasable from the distal end portion 80, thus allowing the distal end portion 80 of the sheath 40 to expand radially.

[0136] FIG. 17 is a partial side cross section view of the distal end of the sheath 40 showing the distal end portion 80 in an unexpanded configuration, and FIG. 18 is a partial side cross section view of the distal end of the sheath 40 showing the distal end portion 80 in an expanded configuration. As illustrated in FIGS. 17 and 18, the ring 140 is configured to expand from the unexpanded configuration (FIG. 17) in the which the ring 140 has a first diameter, to the expanded configuration (FIG. 18) in which the ring 140 has a second, larger, diameter. As provided in FIGS. 17 and 18, the ring 140 maintains the corresponding portion (for example, distal end portion 80) of the expandable sheath 40 in the unexpanded configuration. In some implementations, the ring 140 can also be used to maintain the distal end portion 80 an expanded configuration. For example, expansion of the ring 140 to the expanded configuration provides for corresponding expansion of the expandable sheath 40 / distal end portion 80, allowing passage of the medical device / delivery system passing therethrough.

[0137] As illustrated in FIG. 17, in some implementations, in the unexpanded configuration, the diameter of the ring 140 is less than the unexpanded diameter of the expandable sheath 40. As such, the ring 140 helps to form the reduced diameter shape of the distal end of the sheath 40, and maintains the distal end portion 80 at an unexpanded diameter less than the unexpanded diameter of the elongated body portion 49 of the expandable sheath 40. In some implementations, the ring 140 maintaining the distal end portion 80 at an unexpanded diameter less than the unexpanded diameter of the expandable sheath 40, results in the corresponding constriction / tapering shape of the distal end portion 80 of the expandable sheath 40.

[0138] In some implementations, the ring 140 is biased in the expanded configuration. As such, when the ring 140 is released, the distal end portion 80 of the sheath 40 defaults / biases to theexpanded configuration. For example, in some implementations, the ring 140 is composed of a shape-memory material biased in the expanded configuration.

[0139] In some implementations, as illustrated in FIGS. 19-21, the sheath 40 system includes a release pin 142 removably coupled to the ring 140. In some implementations, when the release pin 142 is uncoupled from the ring 140, the ring 140 moves from the unexpanded configuration to the expanded configuration. In some implementations, the release pin 142 is provided as an elongated pin, lever lock, bayonet lock, or other suitable means for maintaining the ring 140 in the unexpanded configuration.

[0140] In some implementations, the release pin 142 is coupled to a pin opening 144 provided on the ring 140, such that when the release pin 142 is engaged with or maintained within the pin opening 144 the ring 140 is maintained in the unexpanded configuration. When the release pin 142 is removed from the pin opening 144, the ring 140 moves from the unexpanded configuration to / toward the expanded configuration. In some implementations, the pin opening 144 is provided as a channel, eyelet and / or other suitable opening provided on the ring 140. In some implementations, the ring 140 is formed as a c-shaped ring and the pin opening 144 is provided on opposing ends of the opposing edges of the c-shaped ring.

[0141] FIG. 19 illustrates the ring 140 in an unexpanded / closed configuration with the release pin 142 engaged and maintaining the ring 140 in the unexpanded configuration. FIG. 20 illustrates the ring 140 with the release pin 142 being removed, and FIG. 21 shows the ring 140 with the release pin 142 removed and the ring 140 moved to / toward the expanded configuration. As illustrated in FIGS. 19-21, in some implementations, the pin opening 144 is provided on each of opposing free ends of the ring 140. The opposing free ends include a first free end 146 and a second free end 148, where the main body portion 145 of the ring 140 extends around a circumference of the ring 140. As illustrated in FIGS. 19 and 20, the first free end 146 abuts the second free end 148 when the ring 140 is in the in the unexpanded configuration. In some implementations, in the unexpanded configuration, the release pin 142 extends through the pin opening 144 provided on the first free end 146 and the pin opening 144 provided on the second free end 148. In the expanded configuration, provided in FIG. 19, the release pin 142 is removed from the pin opening 144 and the first free end 146 is spaced from the second free end 148.

[0142] In some implementations, the release pin 142 is maintained in the pin opening 1 4 by friction engagement between the release pin 142 and the pin opening 144. In some implementations, the release pin 142 is maintained in the pin opening 144 by a locking feature.

[0143] In some implementations, the release pin 142 is coupled to a pull wire 150 for providing axial force necessary to remove the release pin 142 from the ring 140. In some implementations as illustrated in FIGS. 17 and 18, the pull wire 150 extends within in a pull wire channel 152 provided within / along the sheath 40. For example, movement of the pull wire 150 in the proximal direction along the expandable sheath 40 within the pull wire channel 152 causes the release pin 142 to be removed from the ring 140. In some implementations, the pull wire 150 extends along the expandable sheath 40 to the sheath hub 24 / optional control housing 22 of the expandable sheath 40. Here the pull wire 150 can be manipulated by the user to remove the release pin 142 from the release pin opening 144 / ring 140. With the release pin 142 removed from the pin opening 144, the ring 140 is able to move from the unexpanded configuration to the expanded configuration.

[0144] In some implementations, ring 140 coupled to the distal end portion 80 of the sheath 40. In some implementations, as illustrated in FIGS. 17 and 18, the ring 140 is located at the distal tip 82 and / or tubular- shaped portion 84 distal the braided layer 54 of the expandable sheath 40. In some implementations, the ring 140 is located radially inward of the second polymeric layer 58 and radially outward of the first polymeric layer 52. In some implementations, the ring 140 is positioned between the first polymeric layer 52 and the second polymeric layer 58 during formation of the expandable sheath 40 on a mandrel 120. For example, the ring 140 is positioned over the spun first polymeric layer 52 prior to forming the second polymeric layer 58.

[0145] In accordance with the present disclosure, a medical device (prosthetic device 12) can be delivered through an expandable sheath 40 including the distal end portion 80 as described herein. In some implementations described herein, the expandable sheath 40 is used to deliver a medical device (prosthetic device 12) into a patient, for example, implanting a prosthetic heart valve 12. It is further contemplated that the medical device (prosthetic device 12) can be advanced through the expandable sheath 40 without the expandable sheath 40 being positioned within the patient’s blood vessel. That is, distal end portion 80 of the sheath 40 can be expanded without the sheath 40 being positioned with a patient’s blood vessel and / or exterior to a patient’s body.

[0146] As depicted in part in FIGS. 9-21 , the method includes providing an expandable sheath 40 as described herein. The expandable sheath 40 includes a central lumen 42 extending therethrough which the medical device (prosthetic heart valve 12) and / or delivery apparatus 10 travels into the patient’s vessel in order to deliver, remove, repair, and / or replace a prosthetic device. As described herein, in some implementations, the expandable sheath 40 can comprise a plurality of coaxial layers extending along at least a portion of the length of the sheath 40. In some implementations, the coaxial layers include one or more folded portions extending along a length of the sheath 40. The structure of the coaxial layers is also described in more detail, for example, in U.S. Patent Application No. 16 / 378,417, entitled “Expandable Sheath,” U.S. Patent Application No. 17 / 716,882, entitled “Expandable Sheath,” and U.S. Patent Application No. 14 / 880,109, entitled “Expandable Sheath,” the disclosures of which are herein incorporated by reference.

[0147] When used to deliver the medical device (for example, the implant 12) to the patient, the expandable sheath 40 is inserted at least partially into the patient’s blood vessel. In some implementations, the expandable sheath 40 is inserted into a femoral artery of the patient. In some implementations, an introducer 100 is provided within the central lumen 42 of the sheath 40. The introducer 100 provides axial and radial support to the sheath 40 as it is advanced within the patient’s blood vessel. The introducer 100 is then withdrawn from the sheath 40, leaving the central lumen 42 open / available for the medical device / delivery apparatus 10 to be positioned within the sheath 40. In some implementations, a guide wire can be at least partially inserted into the patient’s blood vessel and the sheath 40 / introducer 100 can be advanced over the guide wire through the blood vessel to the treatment site. In some implementations, accessing the treatment site may require creating an opening in the patient’s heart tissue (for example, foramen ovalis). In some implementations, after the introducer 100 is removed from the sheath 40, a cutting instrument can be advanced through the sheath 40 to create an opening in the patient’s heart tissue.

[0148] With the central lumen of the sheath 40 free of the introducer 100, the medical device (implant 12) is then introduced into the central lumen 42 at the proximal end of the sheath 40. The medical device is then advanced through the central lumen 42 of the sheath 40. In some implementations, the movement of the medical device within the central lumen 42 of the sheath 40 causes the sheath 40 to locally radially expand from the unexpanded configuration to / towardthe expanded configuration, at larger diameter. As the medical device passes through the sheath 40, the portion of the sheath 40 locally contracts at least partially back to / toward the unexpanded configuration. As described herein, the sheath 40 can have a natural, unexpanded outer diameter that will expand locally upon passage of the medical device. The temporary, localized nature of the expansion can reduce trauma to the blood vessel into which the sheath 40 is inserted, along with the surrounding tissue, because only the portion of the sheath 40 occupied by the medical device and / or delivery apparatus 10 expands beyond the sheath’s natural unexpanded diameter and the sheath 40 collapses back to the initial diameter once the medical device / delivery apparatus 10 has passed. This limits the amount and time the vessel tissue must be stretched in order to introduce the prosthetic device.

[0149] In some implementations, the medical device (for example, the implant 12) is provided on the delivery apparatus 10 and / or guide catheter 14 and inserted into the sheath 40 before the sheath 40 is positioned at the treatment site. For example, the delivery apparatus 10 and / or guide catheter 14, with the medical device mounted thereon, can be positioned within the sheath 40 before the sheath 40 is advanced through the patient’s blood vessel.

[0150] As described herein and illustrated in FIGS. 8 and 9, in some implementations, the expandable sheath 40 includes a reduced diameter distal end portion 80 that helps reduce trauma or damage to the blood vessel as the sheath 40 is advanced to the treatment site.

[0151] As shown in FIG. 9, the medical device is advanced within the central lumen 42 of the expandable sheath 40 along and through the distal end portion 80 which causes the distal end portion 80 to locally expand from the unexpanded configuration, in the which the distal end portion 80 has a first diameter, to an expanded configuration in which the distal end portion 80 has a second, larger, diameter. In some implementations, advancing the medical device through the distal end portion 80 causes a tapered portion 55 to locally expand from an unexpanded configuration in the which the braided layer 54 has a first diameter to an expanded configuration in which the braided layer 54 has a second diameter that is larger than the first diameter. For example, as illustrated in FIG. 9, the tapered portion 55 of the braided layer 54 expands due to an outwardly directed radial force exerted on the central lumen 50 of the expandable sheath 40 as the medical device / delivery system passes through the distal end portion 80 of the expandable sheath 40.

[0152] In some implementations, as the medical device moves through the distal end portion 80, the distal end portion 80 (including the tapered portion 55) then locally contracts at least partially back to the unexpanded configuration.

[0153] The medical device can be advanced beyond a distal opening 47 in the expandable sheath 40 to the treatment site within the blood vessel and / or heart tissue of the patient. In some implementations, as the medical device is advanced through the distal opening 47 of the expandable sheath 40, the distal opening 47 flares open. The medical device is deployed beyond distal opening 47 of the sheath 40 and delivered to the patient.

[0154] Once the medical device is delivered to the patient, the delivery apparatus 10 is removed / withdrawn from the sheath 40 and the expandable sheath 40 withdrawn from the patient’s blood vessel.

[0155] In some implementations, as described herein and illustrated in FIGS. 10-12, the first polymeric layer 52 and the second polymeric layer 58 extend along the sheath 40 beyond the distal end 57 of the braided layer 54 and along the distal end portion 80 to form a distal tip 82. In this implementation, advancing the medical device through the distal tip 82 causes the distal end portion 80 and the distal tip 82 to locally expand from an unexpanded configuration in the which the each of the distal end portion 80 and distal tip 82 have a first diameter, to an expanded configuration in which each of the distal end portion 80 and distal tip 82 have a second, larger, diameter. In some implementations, advancing the medical device through the distal tip 82 causes the distal tip 82 and / or the distal end portion 80 of the expandable sheath 40 to tear / split as the distal tip 82 / distal end portion 80 expands from the unexpanded configuration to the expanded configuration.

[0156] In some implementations, as the medical device moves through the distal end portion 80 and distal tip 82, the sheath 40 then locally contracts at least partially back to the unexpanded configuration.

[0157] The medical device can be advanced beyond a distal opening 47 in the expandable sheath 40 to the treatment site within the blood vessel and / or heart tissue of the patient. Once the medical device is delivered to the patient, the delivery apparatus 10 is removed / withdrawn from the sheath 40 and the expandable sheath 40 withdrawn from the patient’s blood vessel.

[0158] In some implementations, as described herein and illustrated in FIGS. 10-12, an elastic band 130 is provided along the distal end portion 80. For example, in some implementationdescribed herein, the first polymeric layer 52 and the second polymeric layer 58 extend beyond the braided layer 54 and along the distal end portion 80 of the expandable sheath 40 to form a distal tip 82. An elastic band 130 can be provided along the distal tip 82 and / or tub ular- shaped portion 84 of the expandable sheath 40, such that the elastic band 130 constricts or otherwise retains at least a portion of the distal end portion 80 of the sheath 40, thereby forming the reduced diameter shape of the distal end of the sheath 40. In some implementations, advancing the medical device through the distal tip 82 causes the elastic band 130 to locally expand from an unexpanded configuration in the which the each of the distal tip 82 and / or the elastic band 130 have a first diameter to an expanded configuration in which each of the distal tip 82 and / or the elastic band 130 have a second, larger, diameter. In some implementations, as the medical device moves through the distal end portion 80, the distal tip 82 and elastic band 130 then locally contracts at least partially back to the unexpanded configuration.

[0159] In some implementations, as described herein and illustrated in FIGS. 13 and 14, the distal end of the sheath 40 is folded inward to form a rounded shape at the distal end 43 of the sheath 40. For example, at portion of the distal end portion 80 of the sheath 40 is folded inward into the central lumen 42 of the sheath 40 forming folded portions 86. As described herein, the distal tip 82 is moved from the folded configuration to the unfolded configuration by the axial movement of the medical device and / or delivery system through the central lumen 42 of the sheath 40. For example, with the distal tip 82 in the folded configuration (FIG. 13), the medical device is advanced within the central lumen 42 of the sheath 40. Contact between the medical device and the distal end 43 of the expandable sheath 40 folded / located within the central lumen 42 of the sheath 40 results in a corresponding axial force against the distal end 43 and moment of the distal tip 82 / folded portion 86 to an unfolded configuration and shown in FIG. 14. The medical device can be advanced beyond a distal opening 47 in the expandable sheath 40 to the treatment site within the blood vessel and / or heart tissue of the patient. Once the medical device is delivered to the patient, the delivery apparatus 10 is removed / withdrawn from the sheath 40 and the expandable sheath 40 withdrawn from the patient’s blood vessel.

[0160] As described herein, in some implementations, the distal tip 82 is biased in a folded configuration such that as the medical device is moved through the distal opening 47 of the sheath 40 the distal tip 82 returns toward the folded configuration. For example, once the medical device is delivered to the patient, the delivery apparatus 10 is removed / withdrawn fromthe sheath 40, the distal tip 82 will return toward the folded configuration. With the delivery apparatus 10 removed from the central lumen 42 of the sheath 40, the sheath 40 can then be withdrawn from the patient’s blood vessel.

[0161] In some implementations, as illustrated in FIGS. 17-21, the sheath 40 includes a ring 140 provided along and / or within the distal end portion 80 for constricting or otherwise retaining at least a portion of the distal end portion 80 of the sheath 40 in an unexpanded configuration. As described herein, before the medical device is advanced through the distal end portion 80 of the sheath 40, the release pin 142 is uncoupled from the ring 140 as described herein. Uncoupling the release pin 142 causes the ring 140 to move from the unexpanded configuration to the expanded configuration, resulting in a corresponding movement of the distal end portion 80 from the unexpanded configuration to the expanded configuration. In some implementations, the expanded diameter of the ring 140 is greater than the unexpanded diameter of the 40 and / or the expanded diameter of the sheath 40. As such, in some implementations, when the ring 140 moves to the expanded configuration the distal end portion 80 has an outwardly flared shape.

[0162] With the distal end portion 80 of the sheath 40 in the expanded configuration, the medical device is advanced beyond a distal opening 47 in the expandable sheath 40 to the treatment site within the blood vessel and / or heart tissue of the patient. Once the medical device is delivered to the patient, the delivery apparatus 10 is removed / withdrawn from the sheath 40 and the expandable sheath 40 withdrawn from the patient’s blood vessel.

[0163] The medical device (for example, the implant 12) can be a prosthetic device mounted in a radially crimped state on the delivery apparatus 10, guide catheter 14, and / or other delivery catheter. Advancing the prosthetic device through the central lumen 42 of the expandable sheath 40 comprises advancing the delivery apparatus 10 / guide catheter 14 and the prosthetic device together through central lumen 42 of the expandable sheath 40 and into a vasculature of the patient. In some implementations, the prosthetic device comprises a prosthetic heart valve mounted in a radially crimped state of the delivery apparatus 10 / guide catheter 14.

[0164] In such implementations, the method includes implanting the prosthetic heart valve at a treatment site within the patient. With the medical device (implant 12) positioned at the treatment site, the medical device can be expanded and implanted at the treatment size within the patient’s blood vessel. In some implementations, the medical device is a self-expanding prosthetic heart valve. In some implementations, the medical device is a balloon expandableprosthetic heart valve. The balloon-expanding heart valve can be mounted on a balloon / balloon catheter provided on the delivery apparatus 10 / guidc catheter 14. To expand the heart valve an inflation fluid is provided to the balloon. After the medical device expanded, the balloon catheter is then deflated and withdrawn from the medical device.

[0165] With the medical device implanted at the treatment site within the patient’s blood vessel, the delivery apparatus 10 / guide catheter 14 can be withdrawn from the sheath 40, and the sheath 40 is then withdrawn from the patient’s blood vessel. In some implementations, the delivery apparatus 10 / guide catheter 14 are removed from the patient’s blood vessel together with the sheath 40. That is, the delivery apparatus 10 / guide catheter 14 are not removed from the sheath 40 before the sheath 40 is removed from the patient. With the sheath 40 and delivery apparatus 10 / guide catheter 14 removed from the patient, the opening in the patient’s blood vessel is closed and the procedure complete.

[0166] Exemplary Aspects

[0167] In view of the described processes and compositions, hereinbelow are described certain more particularly described 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 are somehow limited in some way other than the inherent meanings of the language and formulas literally used therein.

[0168] Example 1. A sheath system for deploying a medical device, the sheath system comprising: an expandable sheath having a central lumen extending therethrough, the expandable sheath including a distal end portion having an unexpanded outer diameter less than an unexpanded outer diameter of a body portion of the sheath.

[0169] Example 2. A sheath system for deploying a medical device, the sheath system comprising: an expandable sheath having a central lumen extending therethrough, the expandable sheath including: a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer comprising a plurality of filaments braided together; and a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first polymeric layer and the second polymeric layer; wherein at least a portion of the expandable sheath is configured to locally expand from an unexpanded configuration in the which the central lumen has a first diameter toan expanded configuration in which the central lumen has a second diameter that is larger than the first diameter. In some implementations, the expansion is due to an outwardly directed radial force exerted on the central lumen of the expandable sheath by a medical device), and then locally contract at least partially back to the unexpanded configuration, wherein the expandable sheath includes a distal end portion configured to locally expand from an unexpanded configuration in the which the central lumen of the expandable sheath along the distal end portion has a first diameter to an expanded configuration in which the central lumen along the distal end portion has a second diameter that is larger than the first diameter.

[0170] Example 3. The sheath system according to any example herein, particularly example 2, wherein an unexpanded outer diameter of the sheath along the distal end portion is less than an unexpanded diameter along a body portion of the sheath extending from the distal end portion and a proximal end of the sheath.

[0171] Example 4. The sheath system according to any example herein, particularly examples 2-3, wherein, in the unexpanded configuration, an inner diameter of the distal end portion decreases toward a distal end of the expandable sheath. In some implementations, the diameter of the central lumen of the expandable sheath decreases from the proximal end to the distal end of the expandable sheath. In some implementations, the diameter of the central lumen decreases distally along the along the tapered distal end portion.

[0172] Example 5. The sheath system according to any example herein, particularly examples 2-4, wherein the distal end portion of the expandable sheath is biased in the unexpanded configuration. In some implementations, the distal end portion is configured to contract at least partially back to the unexpanded configuration as the medical device passes through the distal end portion.

[0173] Example 6. The sheath system according to any example herein, particularly examples 2-5, wherein the expandable sheath is biased toward the unexpanded configuration.

[0174] Example 7. The sheath system according to any example herein, particularly examples 2-6, wherein the first polymeric layer and the second polymeric layer comprise a plurality of longitudinally-extending folds when the expandable sheath is at the first diameter.

[0175] Example 8. The sheath system according to any example herein, particularly example 7, wherein, as a medical device is passed through the expandable sheath, the plurality oflongitudinally-extending folds at least partially unfold to allow the expandable sheath to radially expand.

[0176] Example 9. The sheath system according to any example herein, particularly examples 2- 8, wherein the expandable sheath 40 further includes: a resilient elastic layer radially outward of the braided layer, the elastic layer being configured to apply radial force to the braided layer and the first polymeric layer; wherein the second polymeric layer is radially outward of the elastic layer and bonded to the first polymeric layer such that the braided layer and the elastic layer are encapsulated between the first and second polymeric layers.

[0177] Example 10. The sheath system according to any example herein, particularly example 9, wherein the elastic layer applies an inwardly directed radial force to the braided layer and the first polymeric layer.

[0178] Example 11. The sheath system according to any example herein, particularly example 10, wherein, when a medical device is passed through the expandable sheath, the expandable sheath resiliently returns to the first diameter by the inwardly directed radial force applied by the elastic layer upon passage of the medical device.

[0179] Example 12. The sheath system according to any example herein, particularly examples 2-11, wherein the braided layer includes a distal end portion extending from a distal end of the braided layer toward a proximal end of the braided layer, the distal end portion of the braided layer defining a reduced diameter portion of the braided layer, wherein the distal end portion of the braided layer extends along the distal end portion of the expandable sheath, wherein the distal end portion of the braided layer configured to locally expand from an unexpanded configuration in the which the braided layer has a first diameter to an expanded configuration in which the braided layer has a second diameter that is larger than the first diameter, and then locally contract at least partially back to the unexpanded configuration. In some implementations, the distal end portion of the braided layer expands due to the outwardly directed radial force exerted on the central lumen of the expandable sheath as the medical device / delivery system passes through the distal end portion of the expandable sheath.

[0180] Example 13. The sheath system according to any example herein, particularly example 12, wherein the distal end portion of the braided layer includes a tapered portion, where in the unexpanded configuration the tapered portion defines a decreasing tapered extending from a body portion of the braided layer toward the distal end of the braided layer.

[0181] Example 1 . The sheath system according to any example herein, particularly example 13, wherein the tapered portion of the braided layer is shape-set to form a pleat-pattern.

[0182] Example 15. The sheath system according to any example herein, particularly examples 12-14, wherein the distal end portion of the braided layer includes a curved portion.

[0183] Example 16. The sheath system according to any example herein, particularly examples 12-15, wherein at least a portion of the distal end portion of the braided layer is formed from a shape-memory material. In some implementations, the distal end portion of the braided layer is shape-set to assume an inwardly tapered configuration. In some implementations, the distal end portion of the braided layer is shape-set to assume an outwardly curved configuration along at least a portion of the distal end portion.

[0184] Example 17. The sheath system according to any example herein, particularly examples 2-11, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath.

[0185] Example 18. The sheath system according to any example herein, particularly example 17, wherein the braided layer does not extend into the distal end portion.

[0186] Example 19. The sheath system according to any example herein, particularly examples 17-18, wherein the first polymeric layer and the second polymeric layer extend along the distal end portion to form a distal tip defining a tubular- shaped portion of the distal end portion of the sheath.

[0187] Example 20. The sheath system according to any example herein, particularly example 19, wherein the distal end portion, including the distal tip and tubular- shaped portion, are configured to locally expand from an unexpanded configuration in the which the each of the distal end portion and distal tip / tubular- shaped portion have a first diameter to an expanded configuration in which each of the distal end portion and distal tip / tubular- shaped portion have a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration. In some implementations, the distal end portion distal tip / tubular- shaped portion are configured to move from the unexpanded and expanded configuration due to the outwardly directed radial force exerted on the central lumen of the expandable sheath by a medical device / delivery system passing therethrough.

[0188] Example 21. The sheath system of according to any example herein, particularly examples 17-20, wherein the distal tip / tubular- shaped portion and / or the tapered distal endportion of the expandable sheath is configured to tear / split as the distal tip / di stal end portion expands from the unexpanded configuration to the expanded configuration.

[0189] Example 22. The sheath system according to any example herein, particularly examples 17-21, wherein the distal end and the distal tip / tubular- shaped portion are biased in the unexpanded configuration.

[0190] Example 23. The sheath system according to any example herein, particularly examples17-22, wherein the first polymeric layer and the second polymeric layer are coupled together to form the distal end portion.

[0191] Example 24. The sheath system according to any example herein, particularly example 23, where the first polymeric layer and the second polymeric layer are coupled together by at least one of a mechanical fastener, a chemical fastener or a heat process. In some examples, the first polymeric layer and the second polymeric layer are coupled together by a reflow process.

[0192] Example 25. The sheath system according to any example herein, particularly examples18-24, wherein the expendable sheath is formed by layering the first polymeric layer, the braided layer, and the second polymeric layer over a mandrel, where the mandrel includes an elongated body portion and a tapered distal end portion. In some implementations, the elongated body portion has a diameter corresponding to a diameter of the central lumen of the expandable sheath and the tapered distal end portion has a size and shape corresponding to the distal end portion of the expandable sheath. In some implementations, the first polymeric layer, the braided layer, and the second polymeric layer are layered on to the mandrel such that the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the tapered distal end portion of the mandrel. The mandrel is then removed from the central lumen of the expandable sheath with the joined first polymeric layer and the second polymeric layer forming the distal end portion of the expandable sheath.

[0193] Example 26. The sheath system according to any example herein, particularly examples 18-25, further including an elastic band provided at the distal end portion, the elastic band configured to locally expand from an unexpanded configuration in the which the elastic band has a first diameter, to an expanded configuration in which the elastic band has a second diameter that is larger than the first diameter, and then locally contract at least partially back to the unexpanded configuration. In some implementations, the elastic band is configured to move from the unexpanded and expanded configuration due to the outwardly directed radial force exerted onthe central lumen of the expandable sheath by a medical device / delivery system passing therethrough. In some implementations, the clastic band is provided at the distal tip and / or tubular- shaped portion of the expandable sheath.

[0194] Example 27. The sheath system according to any example herein, particularly example 26, wherein the elastic band is coupled to the distal tip and / or tubular- shaped portion of the expandable sheath.

[0195] Example 28. The sheath system according to any example herein, particularly examples 26-27, wherein the elastic band is biased in the unexpanded configuration.

[0196] Example 29. The sheath system according to any example herein, particularly examples 26-28, wherein the elastic band is located radially inward of the first polymeric layer and radially outward of the second polymeric layer. In some examples, the elastic band is positioned between the first polymeric layer and the second polymeric layer during formation of the expandable sheath on a mandrel. For example, the elastic band is positioned over the spun first polymeric layer prior to forming the second polymeric layer.

[0197] Example 30. The sheath system according to any example herein, particularly examples 26-29, wherein the elastic band is located radially outward of the second polymeric layer.

[0198] Example 31. The sheath system according to any example herein, particularly examples 17-30, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath.

[0199] Example 32. The sheath system according to any example herein, particularly example 31, wherein the braided layer does not extend into the distal end portion.

[0200] Example 33. The sheath system according to any example herein, particularly examples 31-32, wherein the first polymeric layer and the second polymeric extend beyond the distal end portion to form a distal tip of the sheath.

[0201] Example 34. The sheath system of according to any example herein, particularly example 33, wherein the distal tip is movable between a folded configuration and an unfolded configuration, in the folded configuration at least a portion of the distal tip is folded back within the central lumen of the expandable sheath, and in the unfolded configuration the distal tip extends axially in a distal direction along the distal end portion. In some implementations, in the folded configuration, the distal end of the expandable sheath positioned within the central lumenof the expandable sheath extending in a direction towards the proximal end of the expandable sheath.

[0202] Example 35. The sheath system according to any example herein, particularly example 34, wherein, with the distal tip in the folded configuration, a folded portion of the distal tip provides a rounded end surface.

[0203] Example 36. The sheath system according to any example herein, particularly example 34-35, wherein the distal tip is biased in the folded configuration.

[0204] Example 37. The sheath system according to any example herein, particularly examples 31-36, wherein the first polymeric layer and the second polymeric layer are coupled together to form the distal end portion.

[0205] Example 38. The sheath system according to any example herein, particularly example 37, where the first polymeric layer and the second polymeric layer are coupled together by at least one of a mechanical fastener, a chemical fastener or a heat process.

[0206] Example 39. The sheath system according to any example herein, particularly examples 2-38, further including a ring provided at the distal end portion of the sheath, the ring configured to expand from an unexpanded configuration in the which the ring has a first diameter, to an expanded configuration in which the ring has a second diameter that is larger than the first diameter. In some implementations, the ring maintains the corresponding portion of the expandable sheath in the unexpanded configuration.

[0207] Example 40. The sheath system according to any example herein, particularly example 39, wherein, in the unexpanded configuration, a diameter of the ring is less than an unexpanded diameter of the expandable sheath, as such the ring maintains the distal end portion of the sheath at an unexpanded diameter less than the unexpanded diameter of the expandable sheath.

[0208] Example 41. The sheath system according to any example herein, particularly examples 39-40, wherein the ring is biased in the expanded configuration.

[0209] Example 42. The sheath system according to any example herein, particularly examples 39-41, further including a release pin coupled to the ring, wherein, when the release pin is uncoupled from the ring the ring moved from the unexpanded configuration to the expanded configuration.

[0210] Example 43. The sheath system according to any example herein, particularly example 42, wherein the release pin is coupled to a pin opening provided on the ring such that when therelease pin is engaged with or maintained in the pin opening the ring is maintained in the uncxpandcd configuration, wherein removal of the release pin from the pin opening causes the ring to move from the unexpanded configuration toward the expanded configuration.

[0211] Example 44. The sheath system according to any example herein, particularly example 43, wherein the pin opening is provided on each of opposing free ends of the ring , the opposing free ends including a first free end and a second free end, where a main body portion of the ring extends around a circumference of the ring, where the first free end abuts the second free end when the ring is in the in the unexpanded configuration, and the first free end is spaced from the second free end when the ring is in the expanded configuration, wherein, in the unexpanded configuration, the release pin extends through the pin opening provided on the first free end and the pin opening provided on the second free end.

[0212] Example 45. The sheath system according to any example herein, particularly examples 42-44, wherein the release pin is coupled to a pull wire for providing axial force on the release pin to remove it from the ring.

[0213] Example 46. The sheath system according to any example herein, particularly example 45, wherein the pull wire extends within in a pull wire channel in a proximal direction along the expandable sheath.

[0214] Example 47. The sheath system according to any example herein, particularly examples 39-46, wherein the ring coupled to the distal tip and / or tubular wall portion of the expandable sheath. In some implementations, the ring is located at the distal tip and / or tubular- shaped portion distal the braided layer of the expandable sheath.

[0215] Example 48. The sheath system according to any example herein, particularly examples 39-47, wherein the ring is located radially inward of the second polymeric layer and radially outward of the first polymeric layer.

[0216] Example 49. A method of delivering a medical device into a blood vessel of a patient, the method comprising: inserting an expandable sheath at least partially into the blood vessel of the patient, the expandable sheath; introducing a medical device into a proximal end of a central lumen of the sheath; advancing the medical device through the expandable sheath; advancing the medical device through a distal end portion of the expandable sheath causing the distal end portion to locally expand from an unexpanded configuration to an expanded configuration; andadvancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

[0217] Example 50. A method of delivering a medical device into a blood vessel of a patient, the method comprising: inserting an expandable sheath at least partially into the blood vessel of the patient, the expandable sheath having a central lumen extending therethrough and a distal end portion, the expandable sheath including: a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer comprising a plurality of filaments braided together; and a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first and second polymeric layers; introducing a medical device into a proximal end of the central lumen of the sheath; advancing the medical device through the expandable sheath; advancing the medical device through the distal end portion causing the distal end portion to locally expand from an unexpanded configuration in the which the distal end portion has a first diameter to an expanded configuration in which the distal end portion has a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration; and advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

[0218] Example 51. The method according to any example herein, particularly example 50, wherein advancing the medical device through the expandable sheath causes the expandable sheath to locally expand from an unexpanded configuration at a first diameter to an expanded configuration at a second, larger, diameter in response to an outwardly directed radial force exerted on the central lumen by the medical device, and then locally contract at least partially back to the unexpanded configuration as the medical moves within the central lumen.

[0219] Example 52. The method according to any example herein, particularly example 51, wherein the medical device is a prosthetic device mounted in a radially crimped state on a delivery apparatus, wherein advancing the prosthetic device through the central lumen of the expandable sheath comprises advancing the delivery apparatus and the prosthetic device through central lumen of the expandable sheath and into a vasculature of the patient.

[0220] Example 53. The method according to any example herein, particularly example 52, wherein the prosthetic device comprises a prosthetic heart valve and the method further comprises implanting the prosthetic heart valve at a treatment site within the patient.

[0221] Example 54. The method according to any example herein, particularly example 52, wherein the prosthetic heart valve is mounted on a balloon catheter of the delivery apparatus as the prosthetic heart valve is advanced through the sheath.

[0222] Example 55. The method according to any example herein, particularly examples 50-54, wherein the expandable sheath is inserted into a femoral artery of the patient.

[0223] Example 56. The method according to any example herein, particularly examples 50-55, wherein the braided layer extends to / along the distal end portion of the expandable sheath, the braided layer including a tapered portion extending along the distal end portion of the expandable sheath, the tapered portion defining a decreasing tapered extending from a body portion of the braided layer toward the distal end of the braided layer, wherein advancing the medical device through the distal end portion causes a tapered portion to locally expand from an unexpanded configuration in the which the braided layer has a first diameter to an expanded configuration in which the braided layer has a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

[0224] Example 57. The method according to any example herein, particularly examples 50-55, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, wherein advancing the medical device through the distal tip causes the distal end portion and the distal tip to locally expand from an unexpanded configuration in the which the each of the distal end portion and distal tip have a first diameter to an expanded configuration in which each of the distal end portion and distal tip have a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

[0225] Example 58. The method according to any example herein, particularly example 57, wherein advancing the medical device through the distal tip causes the distal tip and / or the distal end portion of the expandable sheath to tear / split as the distal tip / distal end portion expands from the unexpanded configuration to the expanded configuration.

[0226] Example 59. The method according to any example herein, particularly examples 50-55, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, and an elastic band is provided at the distal tip and / or tubular-shaped portion of the expandable sheath, wherein advancing the medical device through the distal tip causes the distal tip and / or the elastic band tolocally expand from an unexpanded configuration in the which the each of the distal tip and / or the clastic band have a first diameter to an expanded configuration in which each of the distal tip and / or the elastic band have a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

[0227] Example 60. The method according to any example herein, particularly examples 50-55, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, and a ring is provided at the distal tip and / or tubular-shaped portion of the expandable sheath, wherein, before advancing the medical device through the distal end portion of the expandable sheath, a release pin is uncoupled from the ring, causing the ring to move from an unexpanded configuration to an expanded configuration having a diameter larger than a diameter of the ring in the unexpanded configuration, resulting in a corresponding movement of the distal end portion from an unexpanded configuration to an expanded configuration having a larger diameter then a diameter of the distal end portion in the unexpanded configuration.

[0228] Example 61. The method according to any example herein, particularly examples 50-55, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along and beyond the distal end portion of the expandable sheath forming a distal tip defining a tubular- shaped portion, the tubular-shaped portion movable between a folded configuration and an unfolded configuration, in the folded configuration the tubular- shaped portion is folded back within the central lumen of the expandable sheath, in the unfolded configuration the tubular- shaped portion extends axially from the distal end of the distal end portion, wherein advancing the medical device through the distal tip causes tubular- shaped portion to move from the folded configuration to the unfolded configuration by the axial movement of the medical device through the distal tip. Method of expanding the distal end of the sheath

[0229] Example 62. A method of expanding an expandable sheath comprising: providing an expandable sheath; introducing a medical device into a central lumen of the sheath; advancing the medical device through the expandable sheath; advancing the medical device through a distal end portion of the sheath, causing the distal end portion to locally expand from an unexpanded configuration in the which the distal end portion has a first diameter to an expandedconfiguration in which the distal end portion has a second, larger, diameter; and advancing the medical device beyond a distal opening in the expandable sheath.

[0230] Example 63. A method of expanding an expandable sheath comprising: providing an expandable sheath having a central lumen extending therethrough and a distal end portion, the expandable sheath including: a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer comprising a plurality of filaments braided together; and a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first and second polymeric layers; introducing a medical device into a proximal end of the central lumen of the sheath; advancing the medical device through the expandable sheath; advancing the medical device through the distal end portion causing the distal end portion to locally expand from an unexpanded configuration in the which the distal end portion has a first diameter to an expanded configuration in which the distal end portion has a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration; and advancing the medical device beyond a distal opening in the expandable sheath.

[0231] Example 64. The method according to any example herein, particularly example 63, wherein the braided layer extends to / along the distal end portion of the expandable sheath, the braided layer including a tapered portion extending along the distal end portion of the expandable sheath, the tapered portion defining a decreasing tapered extending from a body portion of the braided layer toward the distal end of the braided layer, wherein advancing the medical device through the distal end portion causes a tapered portion to locally expand from an unexpanded configuration in the which the braided layer has a first diameter to an expanded configuration in which the braided layer has a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration. In some implementations, the tapered portion of the braided layer expands due to an outwardly directed radial force exerted on the central lumen of the expandable sheath as the medical device / delivery system passes through the distal end portion of the expandable sheath.

[0232] Example 65. The method according to any example herein, particularly example 63, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, wherein advancing the medical device through the distal tip causes the distal end portion and the distal tip to locallyexpand from an unexpanded configuration in the which the each of the distal end portion and distal tip have a first diameter to an expanded configuration in which each of the distal end portion and distal tip have a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

[0233] Example 66. The method according to any example herein, particularly example 65, wherein advancing the medical device through the distal tip causes the distal tip and / or the distal end portion of the expandable sheath to tear / split as the distal tip / distal end portion expands from the unexpanded configuration to the expanded configuration.

[0234] Example 67. The method according to any example herein, particularly example 63, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, and an elastic band is provided at the distal tip and / or tubular- shaped portion of the expandable sheath, wherein advancing the medical device through the distal tip causes the distal tip and / or the elastic band to locally expand from an unexpanded configuration in the which the each of the distal tip and / or the elastic band have a first diameter to an expanded configuration in which each of the distal tip and / or the elastic band have a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

[0235] Example 68. The method according to any example herein, particularly example 63, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, and a ring is provided at the distal tip and / or tubular- shaped portion of the expandable sheath, wherein, before advancing the medical device through the distal end portion of the expandable sheath, a release pin is uncoupled from the ring, causing the ring to move from an unexpanded configuration to an expanded configuration having a diameter larger than a diameter of the ring in the unexpanded configuration, resulting in a corresponding movement of the distal end portion from an unexpanded configuration to an expanded configuration having a larger diameter then a diameter of the distal end portion in the unexpanded configuration.

[0236] Example 69. The method according to any example herein, particularly example 63, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along and beyond the distal end portion of the expandable sheath forming a distal tip defining a tubular- shaped portion, the tubular-shaped portion movable between a foldedconfiguration and an unfolded configuration, in the folded configuration the tubular-shaped portion is folded back within the central lumen of the expandable sheath, in the unfolded configuration the tubular-shaped portion extends axially from the distal end of the distal end portion, wherein advancing the medical device through the distal tip causes tubular- shaped portion to move from the folded configuration to the unfolded configuration by the axial movement of the medical device through the distal tip.

[0237] 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 preferred 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

Claims:

1. A sheath system for deploying a medical device, the sheath system comprising: an expandable sheath having a central lumen extending therethrough, the expandable sheath including: a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer comprising a plurality of filaments braided together; and a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first polymeric layer and the second polymeric layer; wherein at least a portion of the expandable sheath is configured to locally expand from an unexpanded configuration in the which the central lumen has a first diameter to an expanded configuration in which the central lumen has a second diameter that is larger than the first diameter, and then locally contract at least partially back to the unexpanded configuration, wherein the expandable sheath includes a distal end portion configured to locally expand from an unexpanded configuration in the which the central lumen of the expandable sheath along the distal end portion has a first diameter to an expanded configuration in which the central lumen along the distal end portion has a second diameter that is larger than the first diameter.

2. The sheath system of claim 1, wherein the expandable sheath further includes: a resilient elastic layer radially outward of the braided layer, the elastic layer being configured to apply radial force to the braided layer and the first polymeric layer; wherein the second polymeric layer is radially outward of the elastic layer and bonded to the first polymeric layer such that the braided layer and the elastic layer are encapsulated between the first and second polymeric layers.

3. The sheath system of any one of claims 1-2, wherein the braided layer includes a distal end portion extending from a distal end of the braided layer toward a proximal end of the braided layer, the distal end portion of the braided layer defining a reduced diameter portion of the braided layer,wherein the distal end portion of the braided layer extends along the distal end portion of the expandable sheath, wherein the distal end portion of the braided layer configured to locally expand from an unexpanded configuration in the which the braided layer has a first diameter to an expanded configuration in which the braided layer has a second diameter that is larger than the first diameter, and then locally contract at least partially back to the unexpanded configuration, wherein the distal end portion of the braided layer includes a tapered portion, and wherein the unexpanded configuration the tapered portion defines a decreasing tapered extending from a body portion of the braided layer toward the distal end of the braided layer.

4. The sheath system of any one of claims 1-3, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath.

5. The sheath system of claim 4, wherein the braided layer does not extend into the distal end portion.

6. The sheath system of any one of claims 4-5, wherein the first polymeric layer and the second polymeric layer extend along the distal end portion to form a distal tip defining a tubularshaped portion of the distal end portion of the sheath.

7. The sheath system of claim 6, wherein the distal end portion, including the distal tip and tubular- shaped portion, are configured to locally expand from an unexpanded configuration in the which the each of the distal end portion and distal tip / tubular-shaped portion have a first diameter to an expanded configuration in which each of the distal end portion and distal tip / tubular- shaped portion have a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

8. The sheath system of any one of claims 3-7, wherein the distal tip / tubular- shaped portion and / or the tapered distal end portion of the expandable sheath is configured to tear / split as the distal tip / distal end portion expands from the unexpanded configuration to the expanded configuration.

9. The sheath system of any one of claims 5-8, further including an elastic band provided at the distal end portion, the elastic band configured to locally expand from an unexpandedconfiguration in the which the elastic band has a first diameter, to an expanded configuration in which the clastic band has a second diameter that is larger than the first diameter, and then locally contract at least partially back to the unexpanded configuration.

10. The sheath system of claim 9, wherein the elastic band is coupled to the distal tip and / or tubular- shaped portion of the expandable sheath, wherein the elastic band is biased in the unexpanded configuration, wherein the elastic band is located radially inward of the first polymeric layer and radially outward of the second polymeric layer, and wherein the elastic band is located radially outward of the second polymeric layer.

11. The sheath system of any one of claims 4-10, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath.

12. The sheath system of claim 11, wherein the braided layer does not extend into the distal end portion.

13. The sheath system of any one of claims 11-12, wherein the first polymeric layer and the second polymeric extend beyond the distal end portion to form a distal tip of the sheath, wherein the distal tip is movable between a folded configuration and an unfolded configuration, in the folded configuration at least a portion of the distal tip is folded back within the central lumen of the expandable sheath, and in the unfolded configuration the distal tip extends axially in a distal direction along the distal end portion, and wherein, with the distal tip in the folded configuration, a folded portion of the distal tip provides a rounded end surface.

14. The sheath system of claim 1-13, further including a ring provided at the distal end portion of the sheath, the ring configured to expand from an unexpanded configuration in the which the ring has a first diameter, to an expanded configuration in which the ring has a second diameter that is larger than the first diameter.

15. The sheath system of claim 14, wherein, in the unexpanded configuration, a diameter of the ring is less than an unexpanded diameter of the expandable sheath, as such the ring maintains the distal end portion of the sheath at an unexpanded diameter less than the unexpanded diameter of the expandable sheath, wherein the ring is biased in the expanded configuration.

16. The sheath system of claim 14, further including a release pin coupled to the ring, wherein, when the release pin is uncoupled from the ring the ring moved from the unexpanded configuration to the expanded configuration, wherein the release pin is coupled to a pin opening provided on the ring such that when the release pin is engaged with or maintained in the pin opening the ring is maintained in the unexpanded configuration, and wherein removal of the release pin from the pin opening causes the ring to move from the unexpanded configuration toward the expanded configuration.

17. The sheath system of claim 16, wherein the pin opening is provided on each of opposing free ends of the ring , the opposing free ends including a first free end and a second free end, where a main body portion of the ring extends around a circumference of the ring, where the first free end abuts the second free end when the ring is in the in the unexpanded configuration, and the first free end is spaced from the second free end when the ring is in the expanded configuration, wherein, in the unexpanded configuration, the release pin extends through the pin opening provided on the first free end and the pin opening provided on the second free end, wherein the release pin is coupled to a pull wire for providing axial force on the release pin to remove it from the ring, and wherein the pull wire extends within a pull wire channel in a proximal direction along the expandable sheath.

18. The sheath system of any one of claims 14-17, wherein the ring coupled to the distal tip and / or tubular wall portion of the expandable sheath, and wherein the ring is located radially inward of the second polymeric layer and radially outward of the first polymeric layer.

19. A method of delivering a medical device into a blood vessel of a patient, the method comprising: inserting an expandable sheath at least partially into the blood vessel of the patient, the expandable sheath having a central lumen extending therethrough and a distal end portion, the expandable sheath including: a first polymeric layer;a braided layer radially outward of the first polymeric layer, the braided layer comprising a plurality of filaments braided together; and a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first and second polymeric layers; introducing a medical device into a proximal end of the central lumen of the sheath; advancing the medical device through the expandable sheath; advancing the medical device through the distal end portion causing the distal end portion to locally expand from an unexpanded configuration in the which the distal end portion has a first diameter to an expanded configuration in which the distal end portion has a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration; and advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

20. A method of expanding an expandable sheath comprising: providing an expandable sheath having a central lumen extending therethrough and a distal end portion, the expandable sheath including: a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer comprising a plurality of filaments braided together; and a second polymeric layer radially outward of the braided layer and bonded to the first polymeric layer such that the braided layer is encapsulated between the first and second polymeric layers; introducing a medical device into a proximal end of the central lumen of the sheath; advancing the medical device through the expandable sheath; advancing the medical device through the distal end portion causing the distal end portion to locally expand from an unexpanded configuration in the which the distal end portion has a first diameter to an expanded configuration in which the distal end portionhas a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration; and advancing the medical device beyond a distal opening in the expandable sheath.

21. The method of claim 20, wherein the braided layer extends to / along the distal end portion of the expandable sheath, the braided layer including a tapered portion extending along the distal end portion of the expandable sheath, the tapered portion defining a decreasing tapered extending from a body portion of the braided layer toward the distal end of the braided layer, wherein advancing the medical device through the distal end portion causes a tapered portion to locally expand from an unexpanded configuration in the which the braided layer has a first diameter to an expanded configuration in which the braided layer has a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

22. The method of claim 20, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, wherein advancing the medical device through the distal tip causes the distal end portion and the distal tip to locally expand from an unexpanded configuration in the which the each of the distal end portion and distal tip have a first diameter to an expanded configuration in which each of the distal end portion and distal tip have a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration, wherein advancing the medical device through the distal tip causes the distal tip and / or the distal end portion of the expandable sheath to tear / split as the distal tip / distal end portion expands from the unexpanded configuration to the expanded configuration.

23. The method of claim 20, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, and an elastic band is provided at the distal tip and / or tubular-shaped portion of the expandable sheath, wherein advancing the medical device through the distal tip causes the distal tip and / or the elastic band to locally expand from an unexpanded configuration in the whichthe each of the distal tip and / or the elastic band have a first diameter to an expanded configuration in which each of the distal tip and / or the clastic band have a second diameter that is larger than the first diameter and then locally contract at least partially back to the unexpanded configuration.

24. The method of claim 20, wherein the first polymeric layer and the second polymeric layer extend beyond the braided layer and along the distal end portion of the expandable sheath to form a distal tip, and a ring is provided at the distal tip and / or tubular- shaped portion of the expandable sheath, wherein, before advancing the medical device through the distal end portion of the expandable sheath, a release pin is uncoupled from the ring, causing the ring to move from an unexpanded configuration to an expanded configuration having a diameter larger than a diameter of the ring in the unexpanded configuration, resulting in a corresponding movement of the distal end portion from an unexpanded configuration to an expanded configuration having a larger diameter then a diameter of the distal end portion in the unexpanded configuration.

Images