Expandable sheath with distal tip restraining member

Abstract

Disclosed herein are introducer sheaths. The sheaths (40) minimize trauma to patient's vasculature by including a moveable ring (101) with the sheath (40). The ring (101) can allow for formation of a radially compressed configuration of the sheath distal end (43) and / or sheath distal tip (47). The ring (101) can be received within a channel (45) formed in the sidewall of an expandable sheath (40). A pull-wire (110) can be coupled to the ring (101), such that activation of the pull-wire (110) can cause the expandable ring (101) to move along the sheath (40), allowing the sheath distal end (43) to move towards an expanded configuration.

Description

EXPANDABLE SHEATH WITH DISTAL TIP RESTRAINING MEMBERCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 670,033, filed July 11, 2024, which is incorporated by reference 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 examples, 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 wall duringplacement, 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] An implementation of the present disclosure provides an expandable sheath with a movable expandable ring extending around at least a portion of the expandable sheath, providing for a sheath with a compressed or unexpanded distal end and / or tip.

[0012] An example of the present disclosure provides a sheath system for deploying a medical device. The sheath system including: an expandable sheath including a central lumen extending therethrough, at least a portion of the 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; an expandable ring extending around at least a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath; and a pull-wire coupled to the expandable ring and extending in a direction toward a proximal end of the expandable sheath, wherein activating thepull-wire causes the expandable ring to move in a proximal direction along the expandable sheath.

[0013] A further example of the present disclosure provides a method of delivering a medical device through an expandable sheath, the method including: providing an expandable sheath including a central lumen extending therethrough, at least a portion of the 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; providing an expandable ring extending around a distal a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath, a pull-wire coupled to the expandable ring and extending in a direction toward a proximal end of the expandable sheath, where activating the pull-wire causes the expandable ring to move in a proximal direction along the expandable sheath; advancing a medical device within a central lumen of the expandable sheath to a location proximal of the expandable ring causing the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration, where a diameter of the expandable sheath at a location of the expandable ring has a diameter less than the second diameter; activating the pull-wire causing the expandable ring to move in a proximal direction along the expandable sheath including a portion with the medical device, as the expandable ring passes long the portion of the expandable sheath the expandable ring radially expands; further activating the pull-wire causing the expandable ring to move in the proximal direction beyond the portion of the expandable sheath including the medical device, the expandable ring contracting towards an unexpanded configuration and exerting an inwardly directed radial force on the expandable sheath causing the expandable sheath to return toward the unexpanded configuration; advancing the medical device through a portion of the expandable sheath distal the expandable ring causing the expandable sheath to locally expand to / toward the expanded configuration; and advancing the medical device beyond a distal opening in the expandable sheath.

[0014] Another example of the present disclosure provides a method of delivering a medical device into a blood vessel of a patent, the method including: providing an expandable sheath including a central lumen extending therethrough, at least a portion of the sheath is configured to locally expand from an unexpanded configuration in the which the central lumen has a firstdiameter 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 uncxpandcd configuration; providing an expandable ring extending around a distal a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath, a pull-wire coupled to the expandable ring and extending in a direction toward a proximal end of the expandable sheath, where activating the pull-wire causes the expandable ring to move in a proximal direction along the expandable sheath; inserting the expandable sheath at least partially into the blood vessel of the patient; advancing a medical device within a central lumen of the expandable sheath to a location proximal of the expandable ring causing the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration, where a diameter of the expandable sheath at a location of the expandable ring has a diameter less than the second diameter; activating the pull- wire causing the expandable ring to move in a proximal direction along the expandable sheath including a portion with the medical device, as the expandable ring passes long the portion of the expandable sheath the expandable ring radially expands; further activating the pull-wire causing the expandable ring to move in the proximal direction beyond the portion of the expandable sheath including the medical device, the expandable ring contracting towards an unexpanded configuration and exerting an inwardly directed radial force on the expandable sheath causing the expandable sheath to return toward the unexpanded configuration; advancing the medical device through a portion of the sheath distal the expandable ring causing the expandable sheath to locally expand to / toward the expanded configuration; and advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

[0015] Another example of the present disclosure provides a sheath system for deploying a medical device, the sheath system including: an expandable sheath including a central lumen extending therethrough, at least a portion of the 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; a ring disposed around a distal end of the expandable sheath, the ring providing an inwardly directed radial force, maintaining the distal end in the unexpanded configuration; and a delivery apparatus including a guide catheter with a nosecone mounted at a distal end of the guide catheter, theguide catheter and the nosecone sized configured to be received within the central lumen of the expandable sheath; wherein at least a portion of the nosecone has a diameter greater than a diameter of the ring such that advancing the nosecone through the expandable sheath causes corresponding movement of the ring at the location corresponding to the nosecone.

[0016] In a further example, the present disclosure provides a method of delivering a medical device into the blood vessel of a patent, the method including: inserting the expandable sheath at least partially into the blood vessel of the patient, the expandable sheath including a central lumen extending therethrough, at least a portion of the 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, where the expandable sheath includes a ring disposed around a distal end of the expandable sheath, the ring providing an inwardly directed radial force, maintaining the distal end in the unexpanded configuration; advancing a delivery apparatus within a central lumen of the expandable sheath, where the delivery apparatus including a guide catheter with a nosecone mounted at a distal end of the guide catheter, the guide catheter and the nosecone sized configured to be received within the central lumen of the expandable sheath, at least a portion of the nosecone having a diameter greater than a diameter of the ring; advancing the nosecone distally through the expandable sheath proximate the ring causing a corresponding distal movement of the ring; advancing the nosecone at least partially through a distal opening of the expandable sheath such that the ring is received on the nosecone and removed from the distal end of the expandable sheath and the distal end of the expandable sheath moves toward the expanded configuration; further advancing the delivery apparatus through the central lumen of the expandable sheath until a medical device provided on the delivery apparatus is located beyond the distal opening of the expandable sheath; and advancing the medical device beyond a distal opening of the expandable sheath.

[0017] In another example, the present disclosure provides a method of delivering a medical device into the blood vessel of a patent, the method including: inserting the expandable sheath at least partially into the blood vessel of the patient, the expandable sheath including a central lumen extending therethrough, at least a portion of the sheath is configured to locally expand from an unexpanded configuration in the which the central lumen has a first diameter to anexpanded 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, where the expandable sheath includes a ring disposed around a distal end of the expandable sheath, the ring providing an inwardly directed radial force, maintaining the distal end in the unexpanded configuration; advancing a delivery apparatus within a central lumen of the expandable sheath, where the delivery apparatus including a guide catheter with a nosecone mounted at a distal end of the guide catheter, the guide catheter and the nosecone sized configured to be received within the central lumen of the expandable sheath, at least a portion of the nosecone having a diameter greater than a diameter of the ring; advancing the nosecone distally through the expandable sheath proximate the ring causing a corresponding distal movement of the ring; advancing the nosecone at least partially through a distal opening of the expandable sheath such that the ring is received on the nosecone and removed from the distal end of the expandable sheath and the distal end of the expandable sheath moves toward the expanded configuration; further advancing the delivery apparatus through the central lumen of the expandable sheath until a medical device provided on the delivery apparatus is located beyond the distal opening of the expandable sheath; and advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.BRIEF DESCRIPTION OF DRAWINGS

[0018] FIG. 1 is a side view of an exemplary delivery apparatus for a cardiovascular prosthetic device.

[0019] FIG. 2 is a side view of an exemplary introducer device assembly.

[0020] FIG. 3 is a side view of an expandable sheath that can be used in combination with the introducer device assembly of FIG. 2.

[0021] FIG. 4 is a side cross-sectional view of a portion of the expandable sheath of FIG. 3.

[0022] FIG. 5 is a magnified side view of a portion of the expandable sheath of FIG. 3.

[0023] 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.

[0024] FIG. 6B is a magnified side view of a portion of the braided layer of the sheath of FIG. 3.

[0025] 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.

[0026] FIG. 8 is a schematic representation of a cross-sectional view of an example expandable sheath with an expandable ring received within a channel formed within a side wall of the expandable sheath.

[0027] FIG. 9 is a schematic representation of a cross-sectional view of the expandable sheath of FIG. 8 with a medical device disposed within the central lumen of the expandable sheath.

[0028] FIG. 10 is a schematic representation of a cross-sectional view of the expandable sheath of FIG. 9 with the medical device advanced distally through the central lumen of the expandable sheath to a location proximal the distal tip.

[0029] FIG. 11 is a schematic representation of a cross-sectional view of the expandable sheath of FIG. 9 with the medical device further advanced distally through the central lumen of the expandable sheath and the expandable ring withdrawn proximally through the channel.

[0030] FIG. 12 is a schematic representation of a cross-sectional view of the expandable sheath of FIG. 9 with the medical device advanced distally beyond the distal tip of the expandable sheath, illustrating the expanded configuration of the distal tip.

[0031] FIG. 13 is an example delivery apparatus with a ring disposed around a distal end of an expandable sheath, the delivery apparatus including a guide catheter with a nosecone disposed within the central lumen of the expandable sheath.

[0032] FIG. 14 is a schematic representation of a cross-sectional view of an example expandable sheath with a ring disposed around a distal end of the expandable sheath and a delivery system with a nosecone disposed within the central lumen of the expandable sheath.

[0033] FIG. 15 is a schematic representation of a cross-sectional view of the expandable sheath of FIG. 14 with the delivery system nosecone advanced beyond the distal tip of the expandable sheath, illustrating the expanded configuration of the sheath distal tip and the retention of the ring on the delivery system nosecone.

[0034] FIG. 16 is a schematic representation of a magnified view of the expandable sheath of FIG. 14 showing the delivery system nosecone with the ring attached thereto.DETAILED DESCRIPTION

[0035] The following description of certain examples of the inventive concepts should not be used to limit the scope of the claims. Other examples, features, aspects, implementations, and advantages will become apparent to those skilled in the art from the following description. Aswill 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.

[0036] 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.

[0037] Features, integers, characteristics, compounds, chemical moieties, or groups described in conjunction with a particular aspect or example of the present disclosure are to be understood to be applicable to any other aspect or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The present disclosure is not restricted to the details of any foregoing aspects. The present disclosure extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0038] It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

[0039] 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.

[0040] "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.

[0041] 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.

[0042] “Axially” or “axial” as used herein refers to a direction along the longitudinal axis of the sheath.

[0043] 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.

[0044] 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, the expandable sheath can minimize trauma to the vessel by allowing for temporary expansion of a portion of the introducer sheath to accommodate a delivery system, followed by a return to an original diameter once the device passes therethrough.

[0045] Example expandable introducer sheaths are disclosed, for example, in U.S. Patent No. 8,690,936, entitled “Expandable Sheath for Introducing an Endovascular Delivery Device into a Body,” U.S. Patent No. 8,790,387, entitled “Expandable Sheath for Introducing an Endovascular Delivery Device into a Body,” U.S. Patent No. 10,639,152, entitled “Expandable Sheath and Methods of Using the Same,” U.S. Patent No. 10,792,471, entitled “Expandable Sheath,” U.S. Patent No. Application No. 16 / 407,057, entitled “Expandable Sheath with Elastomeric Cross Sectional Portions,” U.S. Patent No. 10,327,896, entitled “Expandable Sheath with Elastomeric Cross Sectional Portions,” U.S. Patent No. 11,273,062, entitled “Expandable Sheath,” Application No. PCT / US2021 / 019514, entitled “Expandable sheath for introducing an endovascular delivery device in to a body,” Application No. PCT / US2021 / 031227, entitled “Expandable sheath for introducing an endovascular delivery device into a body,” Application No. PCT / US2021 / 031275, entitled “Expandable sheath for introducing an endovascular delivery device into a body,” 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 / US 2021 / 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.

[0046] 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 a flex catheter) and a balloon catheter 16 extending through the guide catheter 14. A prosthetic device, such as a prosthetic heart valve 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 slidelongitudinally relative to each other to facilitate delivery and positioning of a prosthetic heart valve 12 at an implantation site in a patient's body as described herein.

[0047] As described in more detail herein, in general, 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 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.

[0048] The prosthetic heart valve 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 example, the prosthetic heart valve 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. 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 12 can be a self-expandable heart valve that is restrained in a radially compressed configuration by a sheath or other component of the delivery apparatus and self-expands 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 examples, the prosthetic heart valve 12 can be a mechanically expandable heart valve that comprises a plurality of strutsconnected 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 examples, 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.

[0049] 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.

[0050] 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. A 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 couple together, as shown in FIG. 2.

[0051] 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, the introducer 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 are discussed below, as well as the operation of the sheath 40 and introducer 100 together.

[0052] 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'svasculature. The sheath 40 may comprise an introducer sheath that is used to introduce a delivery apparatus into the patient's vasculature.

[0053] 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.

[0054] The sheath 40 accordingly may be inserted into the patient’ s vasculature prior to the delivery apparatus being introduced, to provide an entryway 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.

[0055] 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 via the control housing 22 (FIG. 2) for passage through the central lumen 42 of the sheath 40 and the vasculature of the patient.

[0056] 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.

[0057] The sheath 40 may 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 / orintroducer 100 are inserted into the central lumen 42 of the sheath 40. A seal 48 may be 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.

[0058] 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 may be positioned at the proximal end 44 of the sheath 40. The sheath hub 24 may include an internal chamber (not shown) 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.

[0059] The sheath hub 24 may 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 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.

[0060] In some examples, 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 can extend from the handle portion 18 of the guide catheter. Additional examples of introducer devices and expandable sheaths can be found in U.S. Patent No. 11,273,062, which is incorporated by reference in its entirety.

[0061] 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 examples, the expandable sheath 40 can comprise a plurality of coaxial 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 axisCl . In some examples, 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.

[0062] 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.

[0063] In some examples, the inner layer 52 and / or the outer layer 58 can comprise a relatively thin layer of polymeric material. For example, in some examples, the thickness of the inner layer 52 can be from 0.01 mm to 0.5 mm, 0.02 mm to 0.4 mm, or 0.03 mm to 0.25 mm. In some examples aspects, 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.

[0064] In some examples, the inner layer 52 and / or the outer layer 58 can comprise a lubricious, low-friction, and / or relatively non-elastic material. In some examples, the inner layer 52 and / or the outer layer 58 can comprise a polymeric material having a modulus of elasticity of 400 MPa or greater. Exemplary materials can include ultra-high-molecular-weight polyethylene (UHMWPE) (for example, Dyneema®), high-molecular- weight polyethylene (HMWPE), or polyether ether ketone (PEEK). With regard to the inner layer 52 in particular, such a low coefficient of friction materials can facilitate passage of the prosthetic device 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 examples of a sheath 40 can include a lubricious liner on the inner surface of the inner layer 52. Examples of suitable lubricious liners include materials that can further reduce the coefficient of friction of the inner layer 52, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Suitable materials for alubricious liner also include other materials desirably having a coefficient of friction of 0.1 or less.

[0065] Additionally, some examples of the sheath 40 can include an 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 N.V, Heerlen, the Netherlands), as well as other hydrophilic coatings (for example, PTFE, polyethylene, polyvinylidene fluoride), are also suitable for use with the sheath 40. Such hydrophilic coatings may also be 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 examples, a hydrophobic coating, such as Perylene, may be used on the outer surface of the outer layer 58 or the inner surface of the inner layer 52 in order to reduce friction.

[0066] In some examples, the second layer / braided layer 54 can includes 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 and 60B 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 examples, the angle 0 can be from 5° to 70°, 10° to 60°, 10° to 50°, or 10° to 45°. In the illustrated example, the angle 0 is 45°. In some examples, the filaments 60 can also be oriented along three axes and braided in a triaxial braid, or oriented along any number of axes and braided in any suitable braid pattern.

[0067] 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. In particular examples, the filaments 60 can be wires made from metal (for example, Nitinol, stainless steel, etc.), or any of various polymers or polymer composite materials, such as carbon fiber. In certainexamples, the filaments 60 can be round, and can have a diameter of from 0.01 mm to 0.5 mm, 0.03 mm to 0.4 mm, or 0.05 mm to 0.25 mm. In some examples, the filaments 60 can have a flat cross-section with dimensions of 0.01 mm x 0.01 mm to 0.5 mm x 0.5 mm, or 0.05 mm x 0.05 mm to 0.25 mm x 0.25 mm. In one example, filaments 60 having a flat cross-section can have dimensions of 0.1 mm x 0.2 mm. However, other geometries and sizes are also suitable for certain examples. If a braided wire is used, the braid density can be varied. Some examples have a braid density of from ten picks per inch to eighty picks per inch, and can include eight wires, sixteen wires, or up to fifty-two wires in various braid patterns. In some examples, the braided layer 54 can be laser cut from a tube, or laser-cut, stamped, punched, etc., from sheet stock and rolled into a tubular configuration. The braided layer 54 can also be woven or knitted, as desired.

[0068] The third layer / elastic layer 56 can be a resilient, elastic layer (also referred to as an elastic material layer). In certain examples, the elastic layer 56 can be configured to apply force to the underlying inner layer 52 and braided layer 54 in a radial direction (for example, toward the central axis Cl of the sheath) when the sheath expands beyond its natural diameter by passage of the delivery apparatus through the sheath. Stated differently, the elastic layer 56 can be configured to apply encircling pressure to the layers of the sheath beneath the elastic layer 56 to counteract expansion of the sheath. The radially inwardly directed force is sufficient to cause the sheath to collapse radially back to its unexpanded state after the delivery apparatus is passed through the sheath.

[0069] In the illustrated example, the elastic layer 56 can comprise 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 66 A 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.

[0070] In some examples, the elastic layer can comprise an elastomeric material having a modulus of elasticity of 200 MPa or less. In some examples, the elastic layer 56 can comprise a material exhibiting an elongation to break of 200% or greater, or an elongation to break of 400%or greater. The elastic layer 56 can also take other forms, such as a tubular layer comprising an elastomeric material, a mesh, a shrinkable polymer layer such as a heat-shrink tubing layer, etc. In lieu of, or in addition to, the elastic layer 56, the sheath 40 may also include an elastomeric or heat-shrink tubing layer around the outer layer 58. Examples of such elastomeric layers are disclosed in U.S. Patent Nos. 9,301,841, 10,792,471, and 10,856,981, which are incorporated herein by reference. In some examples, the elastic layer 56 can also be radially outward of the polymeric outer layer 58.

[0071] In some examples, one or both of the inner layer 52 and / or the outer layer 58 can be configured to resist axial shortening of the sheath 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 folds / ridges 62 in the layers 52 and 58, can allow the central lumen 42 to expand as a prosthetic device is advanced through it.

[0072] For example, in some examples, the inner layer 52 and the outer layer 58 can be heat- bonded during the manufacturing process such that the braided layer 54 and the elastic layer 56 are encapsulated between the inner layer 52 and the outer layer 58. More specifically, in certain examples, the inner layer 52 and the outer layer 58 can be adhered to each other through the spaces between the filaments 60 of the braided layer 54 and / or the spaces between the elastic bands 66. The inner layer 52 and outer layer 58 can also be bonded or adhered together at the proximal and / or distal ends of the sheath. In certain examples, the inner layer 52 and outer layer 58 are not adhered to the filaments 60. This can allow the filaments 60 to move angularly relative to each other, and relative to the inner layer 52 and outer layer 58, allowing the diameter of the braided layer 54, and thereby the diameter of the sheath, to increase or decrease. As the angle 0 between the filaments 60A and 60B changes, the length of the braided layer 54 can also change. For example, as the angle 0 increases, the braided layer 54 can foreshorten, and as the angle 0decreases, the braided layer 54 can lengthen to the extent permitted by the areas where the inner layer 52 and outer layer 58 arc 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.

[0073] FIG. 7 illustrates radial expansion of the sheath 40 as a prosthetic heart valve 12 is passed through the sheath in the direction of arrow 82 (for example, distally). As the prosthetic heart valve 12 is advanced through the sheath 40, the sheath can resiliently expand to a second diameter D2 that corresponds to a size or diameter of the prosthetic device. As the prosthetic heart valve 12 is advanced through the sheath 40, the prosthetic device can apply longitudinal force to the sheath in the direction of motion by virtue of the frictional contact between the prosthetic device and the inner surface of the sheath. However, as noted above, the inner layer 52 and / or the outer layer 58 can resist axial elongation such that the length LI of the sheath remains constant, or substantially constant. This can reduce or prevent the braided layer 54 from lengthening, and thereby constricting the central lumen 42.

[0074] Meanwhile, the angle 9 between the filaments 60A and 60B can increase as the sheath expands to the second diameter D2 to accommodate the prosthetic valve. This can cause the braided layer 54 to foreshorten. However, because the filaments 60 are not engaged or adhered to the inner layer 52 or outer layer 58, the shortening of the braided layer 54 attendant to an increase in the angle 0 does not affect the overall length LI of the sheath. 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 is advanced through the sheath, without lengthening, and without constricting. Thus, the force required to push the prosthetic implant through the sheath is significantly reduced.

[0075] 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 occupied by the prosthetic device. For example, with reference to FIG. 7, as the prosthetic heart valve 12 moves distally through the sheath 40, the portion of the sheath immediately proximal to the prostheticheart valve 12 can radially collapse back to the initial diameter DI under the influence of the clastic layer 56. The inner layer 52 and outer layer 58 can also buckle as the circumference of the sheath is reduced, causing the ridges 62 and the valleys 64 to reform. This can reduce the size of the sheath required to introduce a prosthetic device of a given size. Additionally, the temporary, localized nature of the expansion can reduce trauma to the blood vessel into which the sheath is inserted, along with the surrounding tissue, because only the portion of the sheath occupied by the prosthetic device expands beyond the sheath’s natural diameter and the sheath collapses back to the initial diameter once the device has passed. This limits the amount of tissue that must be stretched in order to introduce the prosthetic device, and the amount of time for which a given portion of the vessel must be dilated.

[0076] 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. For instance, in one example, a crimped prosthetic heart valve having a diameter of 7.2 mm was successfully advanced through a sheath configured as described above and having a natural outer diameter of 3.7 mm. As the prosthetic valve was advanced through the sheath, 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 through the sheath, during which the outer diameter of the sheath resiliently increased by 216%. In another example, 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.

[0077] In some example systems described herein, the sheath 40 is advanced into the blood vessel with the distal end of the expandable sheath 40 restrained in a non-expanded configuration. Once positioned at the treatment site, the distal end / distal opening 47 of the sheath 40 is released and expands to allow passage of the medical device therethrough. As illustrated in FIGS. 8-16, and described in more detail herein, the example system includes a restraining member that is movable / removable from the distal end of the sheath 40. The restraining member provides an inwardly directed radial force on the expandable sheath 40 maintaining the distal end of the sheath 40 in a radially collapsed / unexpanded configuration. In some aspects describedherein, the restraining member includes an expandable ring 101 coupled to a pull-wire 110. Activation of the pull-wire 110 withdraws the expandable ring 101 from the distal end of the sheath 40. In further aspects of the present disclosure, the restraining member includes a ring 102 disposed around the distal end of the sheath 40, where advancing the delivery apparatus 10 and / or guide catheter 14 through the distal end of the sheath 40 causes the ring 102 to be removed from the sheath 40. Each of these examples provide for an expandable sheath 40 with a restrained distal end / distal opening 47, there the restraining member is easily and safely removed before the medical device is delivered to the treatment site. By restraining the distal end of the sheath 40, the sheath 40 is introduced having a lower profile that is easily expanded to allow passage of the medical device. Various aspects of the sheath 40 and delivery apparatus 10 structure provide for a system that can be safely and predictably advanced through the patient’s blood vessel and uniformly expanded during medical device / delivery system delivery. The sheath 40 and delivery apparatus 10 structure described herein reduces the length of time a procedure takes, as well as reduces the risk of longitudinal or radial vessel tear, and damage to the expandable sheath.

[0078] FIGS. 8-12 illustrate various side cross-sectional views of the distal region of an example expandable sheath 40 according to the present disclosure. As described herein, the expandable sheath 40 includes an expandable ring 101 at the distal end of the sheath 40 maintaining the distal tip of the expandable sheath 40 in a radially collapsed / unexpanded configuration. Activation of the pull- wire 110 causes the expandable ring 101 to move along the expandable sheath 40, thereby allowing the distal tip of the expandable sheath 40 to radially expand.

[0079] FIG. 8 depicts a cross-sectional view of the distal tip of the example expandable sheath 40 prior to advancement of a medical device therethrough. As described herein, the expandable sheath 40 includes a central lumen 42 extending therethrough and a distal opening 47 at the distal end of the sheath 40 / central lumen 42. At least a portion of the sheath 40 is configured to locally expand from an unexpanded configuration, in the which the central lumen 42 has a first diameter, to an expanded configuration in which the central lumen 42 has a second, larger, diameter, and then locally contract at least partially back to the unexpanded configuration. In some instances, the change in configuration can be due to an outwardly directed radial force exerted on the central lumen 42 of the expandable sheath 40 by a medical device 150 passing through the expandable sheath 40 (as shown in FIG. 9).

[0080] As shown in FIG. 8, the sheath 40 includes an expandable ring 101 extending around a portion of the expandable sheath 40 and providing an inwardly directed radial force on the expandable sheath 40. In some examples, the expandable ring 101 is composed of an elastic material including, for example, silicone. In some examples, the expandable ring 101 is biased in an unexpanded configuration. In some examples, in the unexpanded configuration, the expandable ring 101 has a diameter corresponding to the diameter of the expandable sheath 40 in the unexpanded configuration. In further examples, in the unexpanded configuration, the expandable ring 101 has a diameter less than the diameter of the expandable sheath 40 in the unexpanded configuration. As a result, the expandable ring 101 forms a reduced diameter portion of the expandable sheath 40. For example, when the expandable ring 101 is provided at the distal end of the expandable sheath 40, the expandable ring 101 forms a distal tip having a diameter less than the diameter of the elongated body portion of the expandable sheath 40.

[0081] As illustrated in FIGS. 8-12, the pull-wire 110 is coupled to the expandable ring 101, and extends along the expandable sheath 40 in the direction toward the proximal end 44 of the expandable sheath 40. As described herein, activating the pull-wire 110 moves the expandable ring 101 proximally along the expandable sheath 40. In some examples, as depicted in FIGS. 8- 12, the expandable ring 101 is received within a channel 45 formed within the side wall 41 of the expandable sheath 40. The channel 45, and the pull-wire 110, extend toward the proximal end 44 of the expandable sheath 40. In some examples, providing the pull- wire 110 and / or expandable ring 101 within the channel 45 advantageously conceals and / or contains the expandable ring 101 and pull- wire 110 and prevents it from engaging patient anatomy and / or components of the delivery system passing through the central lumen 42 of the expandable sheath 40. In some examples, the channel 45 extends along a portion of the length of the expandable sheath 40. In some examples, the channel 45 extends along the distal tip portion of the expandable sheath 40. In some examples, the channel 45 extends along the distal half of the expandable sheath 40. In some examples, the channel 45 extends along a majority of the length of the expandable sheath 40.

[0082] According to the present disclosure, in some examples as shown in FIG. 12, the channel 45 includes a pull- wire portion (A) and a ring portion (B). In this example, the expandable ring 101 is movable only within the ring portion (B), while the pull-wire 110 is movable within the pull-wire portion (A) and the ring portion (B). As provided in FIG. 12, the pull-wire portion (A)extends between the proximal end 44 of the expandable sheath 40 and the ring portion (B), and the ring portion (B) extends from the pull-wire portion (A) to a location at the distal end 43 of the expandable sheath 40. In some examples, the distal end of the ring portion (B) of the channel 45 terminates proximal to the distal end 43 of the sheath 40. That is, the distal end of the ring portion (B) of the channel 45 is not open and the expandable ring 101 cannot pass beyond or through the distal end of the sheath 40. In some implementations, as illustrated in FIGS. 8-12, a portion of the sheath 40 is provided between the distal end of the ring portion (B) and the distal end 43 of the sheath 40. The ring portion (B) of the channel 45 is sized and configured to accommodate axial (and rotational) movement of the expandable ring 101 within the channel 45, while limiting axial movement of the expandable ring 101 to the ring portion (B). The pull-wire portion (A) includes a portion of the channel 45 sized and configured to accommodate axial movement of the pull-wire 110, and not the expandable ring 101. As such, the length of travel of the expandable ring 101 within the channel 45 is limited to the ring portion (B) of the channel 45 such that as the expandable ring 101 moves proximally within the ring portion (B), interference between the expandable ring 101 and the proximal end of the ring portion (B) prohibits further proximal movement of the expandable ring 101. In some examples, the pull-wire portion (A) of the channel 45 comprises an annular shaped channel extending around at least a portion of the circumference of the expandable sheath 40. For example, the pull-wire portion (A) can have a c- shaped cross-sectional shape. In another example, the pull-wire portion (A) has a circular- shaped cross-sectional shape. In some examples, the pull-wire portion (A) includes multiple channels extending through the side wall of the expandable sheath 40. Similarly, the ring portion (B) of the channel 45 comprises an annular shaped channel extending around at least a portion of the circumference of the expandable sheath 40. For example, the pull- wire portion (A) can have a c- shaped cross-sectional shape. In some examples, the ring portion (B) of the channel 45 comprises an annular shaped channel extending around the entire circumference of the expandable sheath 40.

[0083] In some examples, as described herein, the expandable sheath 40 includes a first polymeric layer 52, and a second polymeric layer 58 radially outward of the first polymeric layer and bonded to the first polymeric layer 52. In some examples, the expandable ring 101 and pullwire 110 are encapsulated between the first polymeric layer 52 and second polymeric layer 58,thereby forming the channel 45 between the first polymeric layer 52 and second polymeric layer 58.

[0084] In some examples, as described herein, the expandable sheath 40 includes the braided layer 54 radially outward of the first polymeric layer 52, where the braided layer 54 comprises a plurality of filaments braided together. In some examples, the channel 45 is formed radially outward of the braided layer 54. In further examples, the channel 45 is formed radially inward of the braided layer 54. As described herein, the expandable sheath 40 can also include a resilient elastic layer 56 radially outward of the braided layer 54, the elastic layer 56 being configured to apply radial force to the braided layer 54 and the first polymeric layer 52, where the second polymeric layer 58 is radially outward of the elastic layer 56 such that the braided layer 54 and the elastic layer 56 are encapsulated between the first polymeric layer 52 and second polymeric layer 58. In some examples, the channel 45 is formed radially inward of the elastic layer 56. In some examples, the channel 45 is formed between the elastic layer 56 and the outer layer 58.

[0085] In some examples, the pull-wire 110 is composed of a non-elastic material. In general, the pull-wire 110 has a diameter less than the wall thickness of the expandable sheath 40 in the expanded configuration. In some examples, when the expandable sheath 40 includes the layered structure as described herein, the pull- wire 110 has a diameter less than the wall thickness of the second polymeric layer 58, first polymeric layer 52, or some combination thereof when the expandable sheath 40 is in both the expanded and unexpanded configuration. As such, the pullwire 110 is received within the channel 45 without causing the corresponding portion of the sheath 40 to expand.

[0086] As described herein, activating the pull-wire 110 causes the expandable ring 101 to move proximally within the channel 45. In some examples, activating the pull-wire 110 comprises moving the pull-wire 110 in a proximal direction along the expandable sheath 40, resulting in a corresponding proximal movement of the expandable ring 101. FIGS. 10-12 depict the expandable ring 101 moving proximally along the expandable sheath 40 via activation of the pull-wire 110. In some examples, when the expandable ring 101 abuts the proximal end of the ring portion (B) of the channel 45, the pull-wire 110 is released from the expandable ring 101.

[0087] In some examples, the pull-wire 110 extends through the channel 45 to the sheath hub 24 coupled to a proximal end 44 of the expandable sheath 40. It is contemplated that the sheath hub 24 can include components for manipulating the pull-wire 110 including. For example, thesheath hub 24 can include a dial and / or a trigger coupled to the pull-wire 110, that when activated causes the pull-wire 110 to move proximally (and / or distally) within the channel 45.

[0088] In accordance with the present disclosure, a medical device 150 can be delivered through an expandable sheath 40 including an expandable ring 101 and pull- wire 110 as described herein. In some examples described herein, the expandable sheath 40 is used to deliver a medical device 150 into a patient, for example, implanting a prosthetic heart valve 12. It is further contemplated that the medical device 150 can be advanced through the expandable sheath 40 without the expandable sheath 40 being positioned within the patient’s blood vessel. That is, the pull-wire 110 can be used to move the expandable ring 101 along the sheath 40 without the sheath 40 being positioned with a patient’s blood vessel and / or exterior to a patient’s body.

[0089] As depicted in part in FIGS. 9-12, 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 150 (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 examples, 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 examples, 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.

[0090] When used to deliver the medical device 150 to the patient, the expandable sheath 40 is inserted at least partially into the patient’s blood vessel. In some examples, the expandable sheath 40 is inserted into a femoral artery of the patient. In some examples, 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 150 / delivery apparatus 10 to be positioned within the sheath 40. In some examples, 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 thetreatment site. In some examples, accessing the treatment site may require creating an opening in the patient’s heart tissue (for example, foramen ovalis). In some examples, 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.

[0091] With the central lumen of the sheath 40 free of the introducer 100, the medical device 150 is then introduced into the central lumen 42 at the proximal end of the sheath 40. The medical device 150 is then advanced through the central lumen 42 of the sheath 40. In some examples, the movement of the medical device 150 within the central lumen 42 of the sheath 40 causes the sheath 40 to locally radially expand from the unexpanded configuration to / toward the expanded configuration, at larger diameter. As the medical device 150 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 150. 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 150 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 150 / delivery apparatus 10 has passed. This limits the amount and time the vessel tissue must be stretched in order to introduce the prosthetic device.

[0092] In some examples, the medical device 150 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 150 mounted thereon, can be positioned within the sheath 40 before the sheath 40 is advanced through the patient’s blood vessel.

[0093] As described herein and illustrated in FIG. 8, in some examples, the expandable sheath 40 includes an expandable ring 101 extending around the distal portion / distal tip of the expandable sheath 40. The expandable ring 101 provides an inwardly directed radial force on the expandable sheath 40. The pull-wire 110 is coupled to the expandable ring 101 and extends toward the proximal end 44 of the expandable sheath 40.

[0094] As shown in FIG. 9, the medical device 150 is advanced within the central lumen 42 of the expandable sheath 40 to a location proximal of the expandable ring 101. As provided in FIG.9, the diameter of the expandable sheath 40 at the location of the expandable ring 101 is less than the expanded diameter of the expandable sheath 40 proximate the medical device 150. In some examples, the diameter of the expandable sheath 40 at the location of the expandable ring 101 is less than the unexpanded (first) diameter of the expandable sheath 40.

[0095] The pull-wire 110 is then activated and withdrawn proximally within the channel 45 provided in the sheath 40. This causes the expandable ring 101 to move in a proximal direction along the expandable sheath 40. FIG. 10 illustrates the expandable ring 101 being withdrawn along the portion of the expandable sheath 40 including the medical device 150. As the expandable ring 101 passes along the medical device 150, the expandable ring 101 radially expands. As described herein, the expandable ring 101 is received within the channel 45 formed within a side wall 41 of the expandable sheath 40, and the pull- wire 110 extends through the channel 45 toward a proximal end 44 of the expandable sheath 40. As a result, activating the pull-wire 110 can cause the expandable ring 101 to move in the proximal direction within the channel 45.

[0096] The pull- wire 110 is then further activated and withdrawn proximally causing the expandable ring 101 to move in the proximal direction beyond medical device 150, as shown in FIG. 11. As the expandable ring 101 moves beyond the medical device 150, the expandable ring 101 contracts towards the unexpanded configuration and exerts an inwardly directed radial force on the expandable sheath 40, causing the expandable sheath 40 to return toward the unexpanded configuration. In some examples, the expandable ring 101 is movable only within the ring portion (B) of the channel 45 as described herein. As such, when the expandable ring 101 abuts the proximal end of the ring portion (B), the pull- wire 110 cannot be further withdrawn. In some examples, when the expandable ring 101 abuts the proximal end of the ring portion (B), the pullwire 110 is released from the expandable ring 101.

[0097] As provided in FIG. 11, the medical device 150 is then advanced through the portion of the expandable sheath 40 distal the expandable ring 101 causing the expandable sheath 40 to locally expand to / toward the expanded configuration. As shown in FIG. 12, the medical device 150 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 examples, as the medical device 150 is advanced through the distal opening 47 of the expandable sheath 40, the distalopening 47 flares open. The medical device is deployed beyond distal opening 47 of the sheath 40 and delivered to the patient.

[0098] 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.

[0099] As described herein, in some examples, providing an expandable ring 101 movable along the expandable sheath 40 and over the medical device 150, provides for improved control of the distal tip of the expandable sheath 40, ensuring that the distal end 43 of the sheath 40 remains unexpanded during advancement within the patient’s blood vessel. The use of the expandable ring 101 also allows for the expandable sheath 40 to stretch over the medical device 150 so that the medical device 150 can be easily pushed through the distal portion of the expandable sheath 40, and not adversely impacting the push forces required for medical device 150 delivery.

[0100] The medical device 150 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 examples, the prosthetic device comprises a prosthetic heart valve 12 mounted in a radially crimped state of the delivery apparatus 10 / guide catheter 14.

[0101] In such examples, the method includes implanting the prosthetic heart valve at a treatment site within the patient. With the medical device 150 positioned at the treatment site, the medical device 150 can be expanded and implanted at the treatment size within the patient’s blood vessel. In some examples, the medical device 150 is a self-expanding prosthetic heart valve. In some examples, the medical device 150 is a balloon expandable prosthetic heart valve. The balloon-expanding heart valve can be mounted on a balloon / balloon catheter provided on the delivery apparatus 10 / guide catheter 14. To expand the heart valve an inflation fluid is provided to the balloon. After the medical device 150 expanded, the balloon catheter is then deflated and withdrawn from the medical device 150.

[0102] With the medical device 150 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 examples, the deliveryapparatus 10 / guide catheter 14 are removed from the patient’s blood vessel together with the sheath 40. That is, the delivery apparatus 10 / guidc catheter 14 arc 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.

[0103] FIGS. 13-16 an example sheath system according to another example of the present disclosure. As described in more detail herein, a ring 102 disposed around the distal end 43 of the expandable sheath 40 secures the expandable sheath 40 against the nosecone 70 of the guide catheter 14 / delivery apparatus 10 during insertion into the patient’s blood vessel. This helps to ensure that the distal end 43 of the sheath 40 does not flare radially outward or otherwise open during insertion into the blood vessel, and helps to prevent trauma to the blood vessel and damage to the sheath 40.

[0104] FIG. 13 provides a side view of the example delivery apparatus and sheath system. In some examples, the distal end 43 of the expandable sheath 40 is biased in the expanded configuration. For example, the distal end 43 of the expandable sheath 40 is biased in a radially outward flared configuration. As provided in FIG. 13, the ring 102 is disposed around the distal end 43 of the expandable sheath 40 maintaining the expandable sheath 40, with a naturally-open distal end 43, in a constricted state during insertion of the expandable sheath 40 into the patient’s body. In some examples, the ring 102 is disposed around the distal end 43 of the expandable sheath 40 and provides an inwardly directed radial force, constraining the distal end 43 of the expandable sheath 40 against the guide catheter 14, particularly, against the distal nosecone 70 of the guide catheter 14.

[0105] The ring 102 can be composed of a non-expandable material. In some examples, the ring 102 is composed of a non-expandable / rigid material such that the ring 102 does not expand radially as it is positioned over the nosecone 70. In some examples, the ring 102 is composed of an elastic material. It is contemplated that the elastic material of the ring 102 is less elastic than the material of the expandable sheath 40.

[0106] In some examples, the ring 102 has a circular cross-sectional shape corresponding to the cross-sectional shape of the expandable sheath 40 and / or guide catheter 14 / nosecone 70. In some examples, the ring 102 has a rounded convex inner surface oriented toward the outer surface of the expandable sheath 40 / nosecone 70. In further examples, the ring 102 has a flat inner surfaceoriented toward the outer surface of the expandable sheath 40 / nosecone 70. In some examples, the inner diameter of the ring 102 is less than the outer diameter of the expandable sheath 40 in the unexpanded configuration. In some examples, the diameter of the inner surface of the ring 102 is less than the unexpanded outer diameter of the expandable sheath 40. As such, positioning the ring 102 over the expandable sheath 40, secures or otherwise constrains the sheath 40 over the guide catheter 14 / nosecone 70.

[0107] As illustrated in FIG. 13 and described herein, the delivery apparatus 10 includes a guide catheter 14 with a nosecone 70 provided at its distal end. The guide catheter 14 and the nosecone 70 are sized and configured to be received within the central lumen 42 of the expandable sheath 40. FIGS. 14-16 provide an enlarged view of the distal end 43 portion of the sheath 40, illustrating movement of the nosecone 70 through the sheath 40, and the corresponding movement of the ring 102 along the sheath 40. In some examples, at least a portion of the nosecone 70 has a diameter greater than the (inner) diameter of the ring 102. As a result, when the nosecone 70 is advanced through the distal end 43 and / or distal opening 47 of the expandable sheath 40, the ring 102 moves distally with respect to and along the sheath 40. That is, advancing the nosecone 70 through the expandable sheath 40 results in a corresponding movement of the ring 102 at the location corresponding to the nosecone 70 having a similar diameter to the inner diameter of the ring 102. When movement of the nosecone 70 is continued distally through the distal end 43 and / or through the distal opening 47 of the sheath 40, the ring 102 moves distally off the sheath 40 and is received on the nosecone 70. With the ring 102 removed from the sheath 40, the distal portion of the expandable sheath 40 moves toward the expanded configuration, for example flares radially outward.

[0108] As illustrated in FIGS. 14-16, in some examples, the proximal portion 72 of the nosecone 70 has a diameter greater than diameter of the ring 102. The larger diameter of the proximal portion 72 prevents the ring 102 from moving proximally along the nosecone 70 and / or expandable sheath 40 at the location corresponding to the proximal portion 72. As shown in FIGS. 14-16, in some examples, the nosecone 70 has a tapered outer surface (tapered distal portion 74) extending from the smaller diameter distal end 76 to the larger diameter proximal portion 72. In some examples, the nosecone 70 has a curved and / or teardrop shaped cross-section extending from the smaller diameter distal end 76 to the larger diameter proximal portion 72.

[0109] In some examples, as the delivery apparatus 10 / guide catheter 14 is advanced within the central lumen 42 of the sheath 40, the proximal portion 72 of the nosecone 70 exerts an outwardly directed radial force on the central lumen 42 of the sheath 40, causing the corresponding portion of the sheath 40 to locally expand from the unexpanded configuration toward the expanded configuration (for example, at the location of the proximal portion 72 of the nosecone 70).

[0110] As described herein, advancing the delivery apparatus 10 distally within the central lumen 42 of the sheath 40 results in a corresponding distal movement of the ring 102. For example, as the nosecone 70 of the guide catheter 14 / delivery apparatus 10 is advanced through the distal opening 47 of the expandable sheath 40 the ring 102 is moved distally along the expandable sheath 40 and received on the 70 / / . As shown in FIG. 15, in some examples, as the nosecone 70 is advanced through the distal opening 47 of the sheath 40, the ring 102 is received on the tapered distal portion 74 of the nosecone 70 extending between a distal end 76 of the nosecone 70 and the proximal portion 72, as shown in FIG. 15. In some examples, as shown in FIG. 16, the nosecone 70 includes a recess 78 for receiving the ring 102. For example, as the nosecone 70 is advanced through the distal opening 47 of the sheath 40 the ring 102 is received in the recess 78. As illustrated in FIG. 16, the ring 102 is retained within the recess 78 as the nosecone 70 is advanced through the distal opening 47. In some examples, the ring 102 is fully received within the recess 78 such that the outer surface of the ring 102 does not extend radially beyond the outer surface of the nosecone 70. In some examples, the recess 78 is provided by an annular shaped groove extending around the nosecone 70. In some examples, the recess 78 is provided on the tapered distal portion 74 of the nosecone 70. In some examples, the recess 78 is provided on the curved / concave portion of the nosecone 70.

[0111] In accordance with the present disclosure, a medical device 150 can be delivered through an expandable sheath 40 including the ring 102 and nosecone 70 structure described herein. As described herein, the expandable sheath 40 can be used to deliver a medical device 150 into a patient, for example, implanting a prosthetic heart valve 12. It is further contemplated that the medical device 150 can be advanced through the expandable sheath 40 without the expandable sheath 40 being positioned within the patient’s blood vessel. That is, the delivery apparatus 10 / guide catheter 14 can be advanced through the sheath 40 to remove the ring 102 from thedistal end 43 of the sheath 40 without the sheath 40 being positioned with a patient’s blood vcsscl / cxtcrior to a patient’s body.

[0112] As depicted in part in FIGS. 13-16, the method includes providing an expandable sheath 40 as described herein. It is contemplated that the method of positioning the sheath 40 and the layered sheath 40 structure will correspond to that described above in reference to FIGS. 1-12. The differences in implementing the ring 102 and nosecone 70 structure for controlling expansion of the distal end 43 of the sheath 40, compared to the expandable ring 101 and pullwire 110 of FIGS. 9-12, is described herein.

[0113] Prior to insertion into the patient’s blood vessel, the delivery apparatus 10 and / or guide catheter 14 is advanced distally within the central lumen 42 of the sheath 40. In some examples, the guide catheter 14 is advanced within the sheath 40. In some examples, the delivery apparatus 10 / guide catheter 14 is positioned such that the distal end 76 of the nosecone 70 does not extend beyond and / or through the distal opening 47 of the sheath 40. In further examples, the guide catheter 14 is advanced within the sheath 40 such that the distal end of the nosecone 70 extends through the distal opening 47 of the sheath 40.

[0114] In some examples, advancing the guide catheter 14 / dclivcry apparatus 10 through the central lumen 42 of the expandable sheath 40 causes the nosecone 70 (and / or medical device) to exert an outwardly directed radial force on the central lumen 42 of the expandable sheath 40 thereby causing a corresponding portion of the expandable sheath 40 to locally expand from the unexpanded configuration to / toward the expanded configuration at the location of the nosecone 70. In some examples, the proximal portion 72 of the nosecone 70 defines the largest diameter portion of the nosecone 70, such that outwardly directed radially force against the sheath 40 is concentrated at the location proximate the proximal portion 72. In examples where the proximal portion 72 defines the largest diameter portion of the nosecone 70, wherein advancing the guide catheter 14 through the central lumen 42 of the expandable sheath 40 causes the proximal portion 72 of the nosecone 70 to exert an outwardly directed radial force on the central lumen 42 of the expandable sheath 40, causing a corresponding portion of the expandable sheath 40 to locally expand from the unexpanded configuration to the expanded configuration at the location of the proximal portion 72 of the nosecone 70.

[0115] In some examples, the outer diameter of the nosecone 70 and / or delivery apparatus 10 / guide catheter 14 is less than the unexpanded inner diameter of the sheath 40. As such,advancing the delivery apparatus 10 / guide catheter 1 within the central lumen 42 of the sheath 40 docs not result in a corresponding expansion of the sheath 40.

[0116] With the guide catheter 14 and nosecone 70 positioned within the sheath 40, the ring 102 is then disposed around the distal end 43 of the sheath 40 securing the sheath 40 against the delivery apparatus 10 and / or nosecone 70 of the guide catheter 14. As described herein, in some examples, the ring 102 provides an inwardly directed radial force, maintaining the distal end 43 of the sheath 40 in the unexpanded configuration and against the nosecone 70. In some examples the ring 102 is positioned on the sheath 40 at a location corresponding to the tapered distal portion 74 of the nosecone 70 such that the distal end 43 of the sheath 40 is constrained between the ring 102 and the tapered distal portion 74 of the nosecone 70. As a result, the distal end 43 of the sheath 40 can be maintained in constrained position against the nosecone 70 of the guide catheter 14, in the unexpanded configuration, during insertion into the patient's blood vessel.

[0117] The expandable sheath 40 is inserted at least partially into the patient’s blood vessel as described herein. The guide catheter 14 / delivery apparatus 10 this then an advanced distally within the central lumen 42 of the sheath 40, resulting in a corresponding distal movement of the ring 102. In particular, in some examples, as the nosecone 70 of the guide catheter 14 is advanced through the sheath 40 interference between the ring 102 and the nosecone 70 (for example, the proximal portion 72 of the nosecone 70 having a diameter greater than the inner diameter of the ring 102) causes the ring 102 to move distally with the guide catheter 14 along the outer surface of the sheath 40. In some examples, as the nosecone 70 is advanced through a distal opening 47 of the sheath 40, the ring 102 is removed from the sheath 40 and received on the nosecone 70. In some examples, the ring 102 is received on the tapered distal portion 74 of the nosecone 70. In some examples, where the nosecone 70 includes a recess 78, advancing the nosecone 70 through the distal opening 47 of the sheath 40 causes the ring 102 to be received within the recess 78.

[0118] Removing the ring 102 from the distal end 43 of the sheath 40 allows the distal end 43 of the sheath 40 to move toward the expanded configuration. As described herein, the distal end 43 of the sheath 40 can be biased in the expanded configuration such that removal of the ring 102 from the distal end 43 of the sheath 40 allows distal end 43 / distal opening 47 the sheath 40 to move to the expanded configuration.

[0119] With the ring 102 removed from the distal end 43 of the sheath 40, the guide catheter 14 / dclivcry apparatus 10 can be further advanced through the central lumen 42 of the expandable sheath 40 until the medical device 150 (provided on the guide catheter 14 / delivery apparatus 10) is positioned beyond the distal opening 47 of the sheath 40. The guide catheter 14 / delivery apparatus 10 can be further advanced through the central lumen 42 such that the medical device 150 is positioned beyond a distal opening 47 of the expandable sheath 40 at the treatment site.

[0120] As described herein, in some examples, the medical device 150 is a prosthetic heart valve mounted in a radially crimped state on the delivery apparatus 10 and / or guide catheter 14. With the medical device 150 positioned at the treatment site, the medical device 150 can be expanded and implanted at the treatment size as described herein.

[0121] With the medical device 150 implanted at the treatment site, the delivery apparatus 10 and / or guide catheter 14 are withdrawn from the sheath 40, and the sheath 40 then withdrawn from the patient’s blood vessel. As described herein, in some examples, the delivery apparatus 10 / guide catheter 14 is removed from the patient’s blood vessel together with the sheath 40. With the sheath 40 removed from the patient, the opening in the patient’s blood vessel is closed and the procedure complete.

[0122] Exemplary Aspects

[0123] 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.

[0124] Example 1: A sheath system for deploying a medical device including: an expandable sheath; and an expandable ring extending around at least a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath, the expandable ring movable along the expandable sheath.

[0125] Example 2: A sheath system for deploying a medical device according to any example herein, particularly example 1, the sheath system including: an expandable sheath including a central lumen extending therethrough, at least a portion of the 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, and then locally contract at least partially back to the unexpanded configuration; an expandable ring extending around at least a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath; and a pull- wire coupled to the expandable ring and extending in a direction toward a proximal end of the expandable sheath, wherein activating the pull- wire causes the expandable ring to move in a proximal direction along the expandable sheath.

[0126] Example 3: The sheath system according to any example herein, particularly examples 1- 2, wherein the expandable ring is received within a channel formed within a side wall of the expandable sheath; wherein the pull-wire extends through the channel toward a proximal end of the expandable sheath.

[0127] Example 4: The sheath system according to any example herein, particularly example 3, wherein the pull- wire extends through the channel to a sheath hub coupled to a proximal end of the expandable sheath.

[0128] Example 5: The sheath system according to any example herein, particularly examples 3-4, wherein activating the pull-wire causes the expandable ring to move in the proximal direction within the channel.

[0129] Example 6: The sheath system according to any example herein, particularly examples 3-5, wherein the channel extends along a portion of a length of the expandable sheath.

[0130] Example 7: The sheath system according to any example herein, particularly examples 3-6, wherein the channel includes a pull-wire portion and a ring portion, such that the pull-wire is movable within the pull- wire portion and the expandable ring is movable within the ring portion, wherein the pull- wire portion extends between a proximal end of the expandable sheath and the ring portion, and the ring portion extends from the pull- wire portion to a location proximate a distal end of the expandable sheath, where a length of travel of the expandable ring within the channel is limited to the ring portion of the channel.

[0131] Example 8: The sheath system according to any example herein, particularly examples 3-7, wherein the expandable sheath includes: a first polymeric layer; and a second polymeric layer radially outward of the first polymeric layer and bonded to the first polymeric layer such that the expandable ring and pull-wire are encapsulated between the first polymeric layer and secondpolymeric layer, thereby forming the channel between the first polymeric layer and second polymeric layer.

[0132] Example 9: The sheath system according to any example herein, particularly example 8, wherein the expandable sheath further includes: a braided layer radially outward of the first polymeric layer, the braided layer including a plurality of filaments braided together; and 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 such that the braided layer and the elastic layer are encapsulated between the first polymeric layer and second polymeric layer.

[0133] Example 10: The sheath system according to any example herein, particularly examples 1-9, wherein when a medical device is passed through the expandable sheath, a diameter of the expandable sheath expands from a first diameter to a second diameter around the medical device, and wherein the sheath resiliently returns to the first diameter by radial force applied by the elastic layer upon passage of the medical device.

[0134] Example 11: The sheath system according to any example herein, particularly examples 8-10, wherein when a medical device is passed through the expandable sheath, a diameter of the expandable sheath expands from a first diameter to a second diameter around the medical device, wherein the first and second polymeric layers include a plurality of longitudinally-extending folds when the expandable sheath is at the first diameter.

[0135] Example 12: The sheath system according to any example herein, particularly example 11, wherein as a medical device is passed through the expandable sheath, the plurality of longitudinally-extending folds at least partially unfold to allow the expandable sheath to radially expand.

[0136] Example 13: The sheath system according to any example herein, particularly examples 1-12, wherein the expandable ring is biased in an unexpanded configuration.

[0137] Example 14: The sheath system according to any example herein, particularly example 13, wherein in the unexpanded configuration, the expandable ring has a diameter less than a diameter of the of the expandable sheath in the unexpanded configuration.

[0138] Example 15: The sheath system according to any example herein, particularly examples 1-14, wherein the expandable ring is composed of an elastic material.

[0139] Example 16: The sheath system according to any example herein, particularly examples 1-15, wherein activating the pull-wire includes moving the pull-wire in a proximal direction along the expandable sheath, resulting in a corresponding proximal movement of the expandable ring.

[0140] Example 17: The sheath system according to any example herein, particularly examples 1-16, wherein the pull- wire is composed of a non-elastic material.

[0141] Example 18: A method of delivering a medical device through an expandable sheath, the method including: providing an expandable sheath and an expandable ring extending around at least portion of the expandable sheath, the expandable ring providing an inwardly directed radial force on the expandable sheath; advancing a medical device within a central lumen of the expandable sheath; moving the expandable ring in a proximal direction along the expandable sheath, where the expandable ring radially expands as it passes along the medical device; moving the expandable ring in the proximal direction beyond the medical device such that the expandable ring contracts toward an unexpanded configuration and exerts an inwardly directed radial force on the expandable sheath; and advancing the medical device beyond a distal opening in the expandable sheath.

[0142] Example 19: A method of delivering a medical device through an expandable sheath according to any example herein, particularly example 18, the method including: providing an expandable sheath including a central lumen extending therethrough, at least a portion of the 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; providing an expandable ring extending around a distal a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath, a pull-wire coupled to the expandable ring and extending in a direction toward a proximal end of the expandable sheath, where activating the pull-wire causes the expandable ring to move in a proximal direction along the expandable sheath; advancing a medical device within a central lumen of the expandable sheath to a location proximal of the expandable ring causing the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration, where a diameter of the expandable sheath at a location of the expandable ring has a diameter less than the second diameter; activating the pull-wire causing the expandable ring tomove in a proximal direction along the expandable sheath including a portion with the medical device, as the expandable ring passes long the portion of the expandable sheath the expandable ring radially expands; further activating the pull-wire causing the expandable ring to move in the proximal direction beyond the portion of the expandable sheath including the medical device, the expandable ring contracting towards an unexpanded configuration and exerting an inwardly directed radial force on the expandable sheath causing the expandable sheath to return toward the unexpanded configuration; and advancing the medical device through a portion of the expandable sheath distal the expandable ring causing the expandable sheath to locally expand to / toward the expanded configuration; advancing the medical device beyond a distal opening in the expandable sheath.

[0143] Example 20: The method according to any example herein, particularly examples 18-19, wherein the expandable ring is received within a channel formed within a side wall of the expandable sheath, and the pull-wire extends through the channel toward a proximal end of the expandable sheath, wherein activating the pull- wire causes the expandable ring to move in the proximal direction within the channel.

[0144] Example 21: The method according to any example herein, particularly examples 18-20, wherein the medical device is a prosthetic device mounted in a radially crimped state on a delivery apparatus.

[0145] Example 22: The method according to any example herein, particularly example 21, wherein the prosthetic device includes a prosthetic heart valve.

[0146] Example 23: The method according to any example herein, particularly example 22, wherein the prosthetic heart valve is mounted on a balloon catheter of the delivery apparatus as the prosthetic heart valve is advanced through the expandable sheath.

[0147] Example 24: A method of delivering a medical device into a blood vessel of a patent, the method including: providing an expandable sheath and an expandable ring extending around at least portion of the expandable sheath, the expandable ring providing an inwardly directed radial force on the expandable sheath; inserting the expandable sheath at least partially into the blood vessel of the patient; advancing a medical device within a central lumen of the expandable sheath; moving the expandable ring in a proximal direction along the expandable sheath, where the expandable ring radially expands as it passes along the medical device; moving the expandable ring in the proximal direction beyond the medical device such that the expandablering contracts toward an unexpanded configuration and exerts an inwardly directed radial force on the expandable sheath; and advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

[0148] Example 25: A method of delivering a medical device into a blood vessel of a patent according to any example herein, particularly example 24, the method including: providing an expandable sheath including a central lumen extending therethrough, at least a portion of the 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; providing an expandable ring extending around a distal a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath, a pull- wire coupled to the expandable ring and extending in a direction toward a proximal end of the expandable sheath, where activating the pull-wire causes the expandable ring to move in a proximal direction along the expandable sheath; inserting the expandable sheath at least partially into the blood vessel of the patient; advancing a medical device within a central lumen of the expandable sheath to a location proximal of the expandable ring causing the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration, where a diameter of the expandable sheath at a location of the expandable ring has a diameter less than the second diameter; activating the pull-wire causing the expandable ring to move in a proximal direction along the expandable sheath including a portion with the medical device, as the expandable ring passes long the portion of the expandable sheath the expandable ring radially expands; further activating the pull-wire causing the expandable ring to move in the proximal direction beyond the portion of the expandable sheath including the medical device, the expandable ring contracting towards an unexpanded configuration and exerting an inwardly directed radial force on the expandable sheath causing the expandable sheath to return toward the unexpanded configuration; advancing the medical device through a portion of the sheath distal the expandable ring causing the expandable sheath to locally expand to / toward the expanded configuration; and advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

[0149] Example 26: The method according to any example herein, particularly examples 24-25, wherein the method further includes: withdrawing the expandable sheath from the patient’s blood vessel.

[0150] Example 27: The method according to any example herein, particularly examples 24-26, wherein the expandable ring is received within a channel formed within a side wall of the expandable sheath, and the pull-wire extends through the channel toward a proximal end of the expandable sheath, wherein activating the pull- wire causes the expandable ring to move in the proximal direction within the channel.

[0151] Example 28: The method according to any example herein, particularly examples 24-27, 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 includes advancing the delivery apparatus and the prosthetic device through central lumen of the expandable sheath and into a vasculature of the patient.

[0152] Example 29: The method according to any example herein, particularly example 28, wherein the prosthetic device includes a prosthetic heart valve and the method further includes implanting the prosthetic heart valve at a treatment site within the patient.

[0153] Example 30: The method according to any example herein, particularly example 29, wherein the prosthetic heart valve is mounted on a balloon catheter of the delivery apparatus as the prosthetic heart valve is advanced through the expandable sheath.

[0154] Example 31: The method according to any example herein, particularly examples 24-30, wherein the expandable sheath is inserted into a femoral artery of the patient.

[0155] Example 32: A sheath system for deploying a medical device including: an expandable sheath; an expandable ring disposed around a distal end of the expandable sheath and providing an inwardly directed radial force on the expandable sheath; and a delivery apparatus sized configured to be received within the central lumen of the expandable sheath; wherein advancing the delivery apparatus through the expandable sheath causes corresponding movement of the ring.

[0156] Example 33: A sheath system for deploying a medical device according to any example herein, particularly example 32, the sheath system including: an expandable sheath including a central lumen extending therethrough, at least a portion of the 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, and then locally contract at least partially back to the unexpanded configuration; a ring disposed around a distal end of the expandable sheath, the ring providing an inwardly directed radial force, maintaining the distal end in the unexpanded configuration; and a delivery apparatus including a guide catheter with a nosecone mounted at a distal end of the guide catheter, the guide catheter and the nosecone sized configured to be received within the central lumen of the expandable sheath; wherein at least a portion of the nosecone has a diameter greater than a diameter of the ring such that advancing the nosecone through the expandable sheath causes corresponding movement of the ring at the location corresponding to the nosecone.

[0157] Example 34: The sheath system according to any example herein, particularly examples 32-33, wherein a proximal portion of the nosecone has a diameter greater than diameter of the ring.

[0158] Example 35: The sheath system according to any example herein, particularly example 32, wherein as the delivery apparatus is advanced within the central lumen of the expandable sheath, the proximal portion exerts an outwardly directed radial force on the central lumen of the expandable sheath, causing a corresponding portion of the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration at the location of the proximal portion of the nosecone.

[0159] Example 36: The sheath system according to any example herein, particularly examples 32-35, wherein as the delivery apparatus is advanced through the central lumen of the expandable sheath in the distal direction, it results in a corresponding distal movement of the ring.

[0160] Example 37: The sheath system according to any example herein, particularly examples 32-36, wherein as the nosecone of the delivery apparatus is advanced through a distal opening of the expandable sheath, the ring is moved distally along the expandable sheath.

[0161] Example 38: The sheath system according to any example herein, particularly examples 32-37, wherein the nosecone includes a proximal portion having a diameter greater than diameter of the ring, wherein as at least a portion of the proximal portion of the nosecone is advanced through the distal opening of the expandable sheath, the ring is moved distally off the expandable sheath and is received on the nosecone.

[0162] Example 39: The sheath system according to any example herein, particularly example 38, wherein as the nosecone is advanced through the distal opening of the expandable sheath, the ring is received on a tapered distal portion of the nosecone extending between a distal end of the nosecone and the proximal portion.

[0163] Example 40: The sheath system according to any example herein, particularly examples 32-39, wherein the nosecone includes a recess, wherein as the nosecone is advanced through the distal opening of the expandable sheath the ring is received in the recess.

[0164] Example 41: The sheath system according to any example herein, particularly examples 32-40, wherein the ring is composed of a non-expandable material.

[0165] Example 42: The sheath system according to any example herein, particularly examples 32-41, wherein the ring has a circular-shaped cross-sectional shape.

[0166] Example 43: The sheath system according to any example herein, particularly examples 32-42, wherein the ring has a diameter less than a diameter of the expandable sheath in the unexpanded configuration.

[0167] Example 44: The sheath system according to any example herein, particularly examples 32-43, wherein the distal end of the expandable sheath is biased in the expanded configuration.

[0168] Example 45: The sheath system according to any example herein, particularly examples 32-44, wherein the distal end of the expandable sheath is biased in a radially outward flared configuration.

[0169] Example 46: The sheath system according to any example herein, particularly examples 32-45, wherein the expandable sheath includes: a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer including a plurality of filaments braided together; 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; and a second polymeric layer 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; wherein the sheath resiliency returns to the first diameter by radial force applied by the elastic layer upon passage of the medical device and / or nosecone.

[0170] Example 47 : A method of delivering a medical device into a blood vessel of a patient, the method including: inserting an expandable sheath at least partially into the blood vessel of the patient, the expandable sheath including a ring disposed around a distal end of theexpandable sheath and providing an inwardly directed radial force on the expandable sheath; advancing a delivery apparatus within a central lumen of the expandable sheath, at least a portion of the delivery apparatus having a diameter greater than a diameter of the ring; advancing the delivery apparatus at least partially through a distal opening of the expandable sheath such that the ring is received on the delivery apparatus and removed from the distal end of the expandable sheath; and advancing a medical device provided on the delivery apparatus is located beyond the distal opening of the expandable sheath.

[0171] Example 48: A method of delivering a medical device into the blood vessel of a patent according to any example herein, particularly example 47, the method including: inserting the expandable sheath at least partially into the blood vessel of the patient, the expandable sheath including a central lumen extending therethrough, at least a portion of the 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, where the expandable sheath includes a ring disposed around a distal end of the expandable sheath, the ring providing an inwardly directed radial force, maintaining the distal end in the unexpanded configuration; advancing a delivery apparatus within a central lumen of the expandable sheath, where the delivery apparatus including a guide catheter with a nosecone mounted at a distal end of the guide catheter, the guide catheter and the nosecone sized configured to be received within the central lumen of the expandable sheath, at least a portion of the nosecone having a diameter greater than a diameter of the ring; advancing the nosecone distally through the expandable sheath proximate the ring causing a corresponding distal movement of the ring; advancing the nosecone at least partially through a distal opening of the expandable sheath such that the ring is received on the nosecone and removed from the distal end of the expandable sheath and the distal end of the expandable sheath moves toward the expanded configuration; further advancing the delivery apparatus through the central lumen of the expandable sheath until a medical device provided on the delivery apparatus is located beyond the distal opening of the expandable sheath; and advancing the medical device beyond a distal opening of the expandable sheath.

[0172] Example 49: The method according to any example herein, particularly examples 47-48, wherein advancing the nosecone at least partially through the distal opening of the expandablesheath causes the ring to he received on a tapered distal portion of the nosecone extending between a distal end of the nosecone and a larger diameter proximal portion.

[0173] Example 50: The method according to any example herein, particularly examples 47-49, wherein the distal end is biased in the expanded configuration such that removal of the ring from the distal end of the expandable sheath allows the expandable sheath to move to the expanded configuration.

[0174] Example 51: The method according to any example herein, particularly examples 47-50, wherein advancing the delivery apparatus through the central lumen of the expandable sheath causes the nosecone (and / or medical device) to exert an outwardly directed radial force on the central lumen of the expandable sheath thereby causing a corresponding portion of the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration at the location of the proximal portion of the nosecone.

[0175] Example 52: The method according to any example herein, particularly examples 47-51, wherein a proximal portion of the nosecone has a diameter greater than diameter of the ring, wherein advancing the delivery apparatus through the central lumen of the expandable sheath causes the proximal portion of the nosecone to exert an outwardly directed radial force on the central lumen of the expandable sheath, causing a corresponding portion of the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration at the location of the proximal portion of the nosecone.

[0176] Example 53: The method according to any example herein, particularly examples 47-52, wherein the medical device is a prosthetic device mounted in a radially crimped state on the delivery apparatus.

[0177] Example 54: The method according to any example herein, particularly example 53, wherein the prosthetic device includes a prosthetic heart valve.

[0178] Example 55: The method according to any example herein, particularly example 54, wherein the prosthetic heart valve is mounted on a balloon catheter (and / or guide catheter) of the delivery apparatus as the prosthetic heart valve is advanced through the expandable sheath.

[0179] Example 56: A method of delivering a medical device into the blood vessel of a patient, the method including: inserting an expandable sheath at least partially into the blood vessel of the patient, the expandable sheath including a ring disposed around its distal end, the ring providing an inwardly directed radial force on the expandable sheath; advancing a deliveryapparatus within a central lumen of the expandable sheath, at least a portion of the delivery apparatus having a diameter greater than a diameter of the ring; advancing the delivery apparatus at least partially through a distal opening of the expandable sheath such that the ring is received on the delivery apparatus and removed from the distal end of the expandable sheath; and advancing a medical device provided on the delivery apparatus is located beyond the distal opening of the expandable sheath to a treatment site within the blood vessel.

[0180] Example 57: A method of delivering a medical device into the blood vessel of a patent according to any example herein, particularly example 56, the method including: inserting the expandable sheath at least partially into the blood vessel of the patient, the expandable sheath including a central lumen extending therethrough, at least a portion of the 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, where the expandable sheath includes a ring disposed around a distal end of the expandable sheath, the ring providing an inwardly directed radial force, maintaining the distal end in the unexpanded configuration; advancing a delivery apparatus within a central lumen of the expandable sheath, where the delivery apparatus including a guide catheter with a nosecone mounted at a distal end of the guide catheter, the guide catheter and the nosecone sized configured to be received within the central lumen of the expandable sheath, at least a portion of the nosecone having a diameter greater than a diameter of the ring; advancing the nosecone distally through the expandable sheath proximate the ring causing a corresponding distal movement of the ring; advancing the nosecone at least partially through a distal opening of the expandable sheath such that the ring is received on the nosecone and removed from the distal end of the expandable sheath and the distal end of the expandable sheath moves toward the expanded configuration; further advancing the delivery apparatus through the central lumen of the expandable sheath until a medical device provided on the delivery apparatus is located beyond the distal opening of the expandable sheath; and advancing the medical device beyond a distal opening in the expandable sheath to a treatment site within the blood vessel.

[0181] Example 58: The method according to any example herein, particularly examples 56-57, wherein the method further includes: withdrawing the delivery apparatus from the expandable sheath; and withdrawing the expandable sheath from the patient’s blood vessel.

[0182] Example 59: The method according to any example herein, particularly examples 56-58, wherein the medical device is a prosthetic device mounted in a radially crimped state on the delivery apparatus.

[0183] Example 60: The method according to any example herein, particularly example 59, wherein the prosthetic device includes a prosthetic heart valve and the method further includes implanting the prosthetic heart valve at the treatment site within the patient.

[0184] Example 61: The method according to any example herein, particularly example 60, wherein the prosthetic heart valve is mounted on a balloon catheter (and / or guide catheter) of the delivery apparatus as the prosthetic heart valve is advanced through the expandable sheath.

[0185] Example 62: The method according to any example herein, particularly examples 56-61, wherein the expandable sheath is inserted into a femoral artery of the patient.

[0186] 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

CLAIMS1. A sheath system for deploying a medical device comprising: an expandable sheath including a central lumen extending therethrough, wherein at least a portion of the 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; an expandable ring extending around at least a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath; and a pull-wire coupled to the expandable ring and extending in a direction toward a proximal end of the expandable sheath, wherein activating the pull-wire causes the expandable ring to move in a proximal direction along the expandable sheath.

2. The sheath system of claim 1, wherein the expandable ring is received within a channel formed within a side wall of the expandable sheath; wherein the pull-wire extends through the channel toward a proximal end of the expandable sheath.

3. The sheath system of claim 2, wherein the pull-wire extends through the channel to a sheath hub coupled to a proximal end of the expandable sheath, wherein activating the pull-wire causes the expandable ring to move in the proximal direction within the channel, wherein the channel extends along a portion of a length of the expandable sheath.

4. The sheath system of any one of claims 2-3, wherein the channel includes a pullwire portion and a ring portion, such that the pull-wire is movable within the pull-wire portion and the expandable ring is movable within the ring portion, wherein the pull- wire portion extends between a proximal end of the expandable sheath and the ring portion, and the ring portion extends from the pull-wire portion to a location proximate a distal end of the expandable sheath, where a length of travel of the expandable ring within the channel is limited to the ring portion of the channel.

5. The sheath system of any one of claims 2-4, wherein the expandable sheath includes:a first polymeric layer; a second polymeric layer radially outward of the first polymeric layer and bonded to the first polymeric layer such that the expandable ring and pull- wire are encapsulated between the first polymeric layer and second polymeric layer, thereby forming the channel between the first polymeric layer and second polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer comprising a plurality of filaments braided together; and 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 such that the braided layer and the elastic layer are encapsulated between the first polymeric layer and second polymeric layer.

6. The sheath system of claim 5, wherein when a medical device is passed through the expandable sheath, a diameter of the expandable sheath expands from a first diameter to a second diameter around the medical device, wherein the sheath resiliently returns to the first diameter by radial force applied by the elastic layer upon passage of the medical device, wherein when a medical device is passed through the expandable sheath, a diameter of the expandable sheath expands from a first diameter to a second diameter around the medical device, wherein the first and second polymeric layers comprise a plurality of longitudinally- extending folds when the expandable sheath is at the first diameter, and wherein, as a medical device is passed through the expandable sheath, the plurality of longitudinally-extending folds at least partially unfold to allow the expandable sheath to radially expand.

7. The sheath system of any one of claims 1-6, wherein activating the pull- wire comprises moving the pull-wire in a proximal direction along the expandable sheath, resulting in a corresponding proximal movement of the expandable ring.

8. A method of delivering a medical device through an expandable sheath, the method comprising:providing an expandable sheath including a central lumen extending therethrough, at least a portion of the 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; providing an expandable ring extending around a distal a portion of the expandable sheath and providing an inwardly directed radial force on the expandable sheath, a pull-wire coupled to the expandable ring and extending in a direction toward a proximal end of the expandable sheath, where activating the pull- wire causes the expandable ring to move in a proximal direction along the expandable sheath; advancing a medical device within a central lumen of the expandable sheath to a location proximal of the expandable ring causing the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration, where a diameter of the expandable sheath at a location of the expandable ring has a diameter less than the second diameter; activating the pull-wire causing the expandable ring to move in a proximal direction along the expandable sheath including a portion with the medical device, as the expandable ring passes long the portion of the expandable sheath the expandable ring radially expands; further activating the pull- wire causing the expandable ring to move in the proximal direction beyond the portion of the expandable sheath including the medical device, the expandable ring contracting towards an unexpanded configuration and exerting an inwardly directed radial force on the expandable sheath causing the expandable sheath to return toward the unexpanded configuration; advancing the medical device through a portion of the expandable sheath distal the expandable ring causing the expandable sheath to locally expand to / toward the expanded configuration; and advancing the medical device beyond a distal opening in the expandable sheath.

9. The method of claim 8, wherein expandable ring is received within a channel formed within a side wall of the expandable sheath, and the pull-wire extends through the channel toward a proximal end of the expandable sheath; wherein activating the pull-wire causes the expandable ring to move in the proximal direction within the channel.

10. A sheath system for deploying a medical device comprising: an expandable sheath including a central lumen extending therethrough, at least a portion of the 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, and then locally contract at least partially back to the unexpanded configuration; a ring disposed around a distal end of the expandable sheath, the ring providing an inwardly directed radial force, maintaining the distal end in the unexpanded configuration; and a delivery apparatus including a guide catheter with a nosecone mounted at a distal end of the guide catheter, the guide catheter and the nosecone sized configured to be received within the central lumen of the expandable sheath; wherein at least a portion of the nosecone has a diameter greater than a diameter of the ring such that advancing the nosecone through the expandable sheath causes corresponding movement of the ring at a location corresponding to the nosecone.

11. The sheath system of claim 10, wherein a proximal portion of the nosecone has a diameter greater than diameter of the ring, wherein as the delivery apparatus is advanced within the central lumen of the expandable sheath, the proximal portion exerts an outwardly directed radial force on the central lumen of the expandable sheath, causing a corresponding portion of the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration at the location of the proximal portion of the nosecone.

12. The sheath system of claim 11, wherein as the delivery apparatus is advanced through the central lumen of the expandable sheath in the distal direction results in a corresponding distal movement of the ring, wherein as the nosecone of the delivery apparatus is advanced through a distal opening of the expandable sheath the ring is moved distally along the expandable sheath.

13. The sheath system of claim 12, wherein the nosecone includes a proximal portion having a diameter greater than diameter of the ring, wherein as at least a portion of the proximal portion of the nosecone is advanced through the distal opening of the expandable sheath, the ring is moved distally off the expandable sheath and is received on the nosecone.

14. The sheath system of claim 13, wherein as the nosecone is advanced through the distal opening of the expandable sheath the ring is received on a tapered distal portion of the nosecone extending between a distal end of the nosecone and the proximal portion.

15. The sheath system of any one of claims 12-14, wherein the nosecone includes a recess, wherein as the nosecone is advanced through the distal opening of the expandable sheath the ring is received in the recess.

16. The sheath system of any one of claims 10-15, wherein the expandable sheath includes; a first polymeric layer; a braided layer radially outward of the first polymeric layer, the braided layer comprising a plurality of filaments braided together; 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; a second polymeric layer 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; wherein the sheath resiliently returns to the first diameter by radial force applied by the elastic layer upon passage of the medical device and / or nosecone, and wherein the distal end of the expandable sheath is biased in a radially outward flared configuration.

17. A method of delivering a medical device into a blood vessel of a patent, the method comprising: inserting an expandable sheath at least partially into the blood vessel of the patient, the expandable sheath including a central lumen extending therethrough, at least a portion of the 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, where the expandable sheath includes a ring disposed around a distal end of the expandable sheath, the ring providing an inwardly directed radial force, maintaining the distal end in the unexpanded configuration;advancing a delivery apparatus within a central lumen of the expandable sheath, where the delivery apparatus including a guide catheter with a nosecone mounted at a distal end of the guide catheter, the guide catheter and the nosecone sized configured to be received within the central lumen of the expandable sheath, at least a portion of the nosecone having a diameter greater than a diameter of the ring; advancing the nosecone distally through the expandable sheath proximate the ring causing a corresponding distal movement of the ring; advancing the nosecone at least partially through a distal opening of the expandable sheath such that the ring is received on the nosecone and removed from the distal end of the expandable sheath and the distal end of the expandable sheath moves toward the expanded configuration; further advancing the delivery apparatus through the central lumen of the expandable sheath until a medical device provided on the delivery apparatus is located beyond the distal opening of the expandable sheath; and advancing the medical device beyond a distal opening of the expandable sheath.

18. The method of claim 17, wherein advancing the nosecone at least partially through the distal opening of the expandable sheath causes the ring to be received on a tapered distal portion of the nosecone extending between a distal end of the nosecone and a larger diameter proximal portion, wherein distal end is biased in the expanded configuration such that removal of the ring from the distal end of the expandable sheath allows the expandable sheath to move to the expanded configuration.

19. The method of any one of claims 17-18, wherein advancing the delivery apparatus through the central lumen of the expandable sheath causes the nosecone to exert an outwardly directed radial force on the central lumen of the expandable sheath thereby causing a corresponding portion of the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration at the location of the proximal portion of the nosecone.

20. The method of any one of claims 17-19, wherein a proximal portion of the nosecone has a diameter greater than diameter of the ring,wherein advancing the delivery apparatus through the central lumen of the expandable sheath causes the proximal portion of the nosecone to exert an outwardly directed radial force on the central lumen of the expandable sheath, causing a corresponding portion of the expandable sheath to locally expand from the unexpanded configuration to the expanded configuration at the location of the proximal portion of the nosecone.

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