Patent Description:
A wide variety of intracorporeal medical devices have been developed for medical use, for example, surgical and/or intravascular use. In some instances, performing percutaneous medical procedures may require insertion and/or maneuvering of relatively large medical devices through a vasculature. However, inserting the medical device into the vasculature may result in undesirable forces being applied to the vessel walls. For example, as the medical device passes into and/or through the vasculature, it may make undesirable contact with one or more vessel walls. This contact may cause injury to the vessel as the medical device is navigated into calcified or diseased vessels. In some instances, an introducer may be utilized to facilitate the insertion of medical devices into the vessel. Further, vessel trauma resulting from forces applied to the vessel wall by a medical device may be lessened by minimizing the size of an introducer used to access the vessel. Therefore, it may be desirable to design an introducer having a reduced insertion profile, yet capable of expansion when necessary (e.g., during the passage of a medical device therethrough). Of the known medical devices and methods, each has certain advantages and disadvantages. There is an ongoing need to provide alternative medical devices as well as alternative methods for manufacturing and/or using medical devices. <CIT> discloses an expandable sheath for introducing a prosthetic device, such as a heart valve, into a patient. <CIT> discloses a selfdilating catheter introducer and obturator system for introducing implantable medical devices into a body cavity. <CIT> discloses an expandable introducer sheath formed in two or more layers. <CIT> discloses an insertion element configured for cooperation with an insertion device for the insertion of a medical implant into a human or animal body. And <CIT> discloses a device including a hollow pipe with a variable diameter is used for medical procedures.

The present invention is directed to a medical radially expandable introducer sheath as set forth in
the appended claims. The introducer sheath comprises a tubular member comprising an inner layer and an outer layer coaxially disposed about a central longitudinal axis of the introducer sheath, the tubular member being configured to shift between an unexpanded configuration to an expanded configuration. The inner layer is circumferentially discontinuous along at least a portion of its length. At least a first portion of the inner layer is configured to move circumferentially relative to the outer layer when shifting between the unexpanded and expanded configurations. The inner layer comprises a plurality of longitudinally-oriented elements, wherein the plurality of longitudinally-oriented elements at least partially circumferentially overlap each other in the unexpanded configuration. The plurality of longitudinally-oriented elements circumferentially overlap each other less as the tubular member shifts from the unexpanded configuration toward the expanded configuration. The plurality of longitudinally-oriented elements is circumferentially spaced apart from each other in the expanded configuration.

While aspects of the disclosure are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular embodiments described.

The following description should be read with reference to the drawings, which are not necessarily to scale, wherein like reference numerals indicate like elements throughout the several views. The detailed description and drawings are intended to illustrate but not limit the claimed invention. Those skilled in the art will recognize that the various elements described and/or shown may be arranged in various combinations and configurations without departing from the scope of the disclosure. The detailed description and drawings illustrate example embodiments of the claimed invention. However, in the interest of clarity and ease of understanding, while every feature and/or element may not be shown in each drawing, the feature(s) and/or element(s) may be understood to be present regardless, unless otherwise specified.

The term "extent" may be understood to mean a greatest measurement of a stated or identified dimension, unless the extent or dimension in question is preceded by or identified as a "minimum", which may be understood to mean a smallest measurement of the stated or identified dimension. For example, "outer extent" may be understood to mean a maximum outer dimension, "radial extent" may be understood to mean a maximum radial dimension, "longitudinal extent" may be understood to mean a maximum longitudinal dimension, etc. Each instance of an "extent" may be different (e.g., axial, longitudinal, lateral, radial, circumferential, etc.) and will be apparent to the skilled person from the context of the individual usage. Generally, an "extent" may be considered a greatest possible dimension measured according to the intended usage, while a "minimum extent" may be considered a smallest possible dimension measured according to the intended usage. In some instances, an "extent" may generally be measured orthogonally within a plane and/or cross-section, but may be, as will be apparent from the particular context, measured differently - such as, but not limited to, angularly, radially, circumferentially (e.g., along an arc), etc..

Diseases and/or medical conditions that impact the cardiovascular system are prevalent throughout the world. Some mammalian hearts (e.g., human, etc.) include four heart valves: a tricuspid valve, a pulmonary valve, an aortic valve, and a mitral valve. The purpose of the heart valves is to allow blood to flow through the heart and from the heart into the major blood vessels connected to the heart, such as the aorta and the pulmonary artery, for example. In a normally functioning heart valve, blood is permitted to pass or flow downstream through the heart valve (e.g., from an atrium to a ventricle, from a ventricle to an artery, etc.) when the heart valve is open, and when the heart valve is closed, blood is prevented from passing or flowing back upstream through the heart valve (e.g., from a ventricle to an atrium, etc.). Some relatively common medical conditions may include or be the result of inefficiency, ineffectiveness, or complete failure of one or more of the valves within the heart. Treatment of defective heart valves poses other challenges in that the treatment often requires the repair or outright replacement of the defective valve. Such therapies may be highly invasive to the patient. Disclosed herein are medical devices that may be used within a portion of the cardiovascular system in order to diagnose, treat, and/or repair the system. At least some of the medical devices disclosed herein may include a replacement heart valve (e.g., a replacement aortic valve, a replacement mitral valve, etc.) and may reduce, treat, and/or prevent the occurrence of defects such as (but not limited to) regurgitation, leaflet prolapse, and/or valve stenosis. In addition, the devices disclosed herein may deliver the replacement heart valve percutaneously and, thus, may be much less invasive to the patient, although other surgical methods and approaches may also be used. The devices disclosed herein may also provide a number of additional desirable features and benefits as described in more detail below.

<FIG> illustrates an example introducer sheath <NUM> (e.g., delivery sheath, access sheath, etc.). The introducer sheath <NUM> may include a tubular member <NUM> having a proximal end attached to a distal end of a hub member <NUM>. The tubular member <NUM> may include a proximal section <NUM> and a distal section <NUM>. The introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM> may include and/or define a lumen <NUM> extending longitudinally through the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM> along and/or coaxial with a central longitudinal axis <NUM> of the introducer sheath <NUM>.

In some embodiments, the distal section <NUM> of the tubular member <NUM> may include a tapered region <NUM> positioned and/or extending distally of the proximal section <NUM> of the tubular member <NUM>. In some embodiments, at least a portion of the distal section <NUM> of the introducer sheath <NUM> may have a substantially constant outer diameter region extending distally from and/or which transitions into the tapered region <NUM>. At least a portion of tapered region <NUM> may have an outer diameter which is greater than the outer diameter of the at least a portion of the distal section <NUM> having the substantially constant outer diameter region extending distally from and/or which transitions into the tapered region <NUM>. However, this is not intended to be limiting. It is contemplated that any portion of the introducer sheath <NUM> may include any number of tapered portions, constant outer diameter regions, and/or combinations thereof.

In some embodiments, the proximal section <NUM> of the tubular member <NUM> may optionally include a spring member. In some examples, a covering may be positioned along and/or be disposed on an outer surface, an inner surface, and/or both the inner and outer surfaces of the spring member. For example, in some embodiments, the spring member may be positioned between (e.g., laminated) an outer covering positioned along and/or disposed on the outer surface of spring member and an inner covering may be positioned along and/or disposed on the inner surface of the spring member.

Additionally, in some embodiments, the hub member <NUM> may optionally include a hemostatic valve or seal disposed therein. The hemostatic valve or seal may prevent fluid(s) (e.g., blood, etc.) from flowing proximally through the lumen <NUM> of the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM>. In at least some examples, the hub member <NUM> may include a port in fluid communication with the lumen <NUM> of the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM>.

In some embodiments, the introducer sheath <NUM> may permit a medical device (e.g., a medical implant, a replacement heart valve delivery system, etc.) to pass through the hub member <NUM>, the proximal section <NUM>, and the distal section <NUM>. In one example, the medical device may pass through the lumen <NUM> of the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM> while being inserted into a body lumen. For example, the introducer sheath <NUM> may be configured to radially expand such that the introducer sheath <NUM> may accommodate and/or pass medical devices which have an outer diameter or maximum outer extent greater than an inner diameter or inner extent of the lumen <NUM> of the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM>.

In at least some embodiments, the tubular member <NUM> may comprise an inner layer <NUM> and an outer layer <NUM> coaxially disposed about the central longitudinal axis <NUM> of the introducer sheath <NUM>. In some embodiments, at least a portion of an outer surface of the inner layer <NUM> may be in contact with and/or in engagement with at least a portion of an inner surface of the outer layer <NUM>. In some embodiments, at least a portion of an outer surface of the inner layer <NUM> may be in sliding contact with and/or in engagement with at least a portion of an inner surface of the outer layer <NUM>. Some suitable but non-limiting materials for the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the outer layer <NUM>, and/or the inner layer <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

In some embodiments, the introducer sheath <NUM>, the tubular member <NUM>, and/or the distal section <NUM> may be configured to shift between an unexpanded configuration, as shown in <FIG> for example, a partially expanded configuration (e.g., <FIG>), and/or a fully expanded configuration (e.g., <FIG>). The skilled person will recognize that the example configurations described immediately above are illustrative only and are not intended to be limiting. As such, in some examples, the configuration shown in <FIG> may correspond to a fully expanded configuration and/or the configuration shown in <FIG> may correspond to a partially expanded configuration. In some embodiments, the fully expanded configuration may be defined by a maximum outer extent of a medical device being passed through the lumen <NUM> of the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM>. Other configurations and arrangements are also contemplated.

In most examples, the lumen <NUM> of the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM> is circumferentially closed and/or isolated from any surrounding and/or outside lumen or environment except for the port in the hub member <NUM> and/or a distal opening at a distalmost end of the lumen <NUM>. As seen in <FIG>, for example, at least a first portion of the inner layer <NUM> may be configured to move circumferentially relative to the outer layer <NUM> (or at least a first portion of the outer layer <NUM> may be configured to move circumferentially relative to the inner layer <NUM>) when shifting between the unexpanded configuration, the partially expanded configuration, and/or the fully expanded configuration, as will be explained in more detail below.

In some embodiments, the inner layer <NUM> may be circumferentially discontinuous along at least a portion of its length. For example, the inner layer <NUM> may include a cut <NUM> (e.g., a slit, a separation, etc.) extending through the inner layer <NUM>. In some embodiments, the outer layer <NUM> may be circumferentially discontinuous along at least a portion of its length. For example, the outer layer <NUM> may include a cut <NUM> (e.g., a slit, a separation, etc.) extending through the outer layer <NUM>. For the purpose of this disclosure, discontinuous may be understood to mean or refer to an element that does not extend in a continuous circumference and/or does not completely surround the relevant or corresponding axis or feature (e.g., the lumen <NUM>, the central longitudinal axis <NUM>). For example, as viewed along the central longitudinal axis <NUM>, the inner layer <NUM> may develop a gap <NUM> (e.g., a space, etc.) from one radial point to another radial point, which may be referred to as a gap angle between opposing sides or faces of the cut <NUM>. The inner layer <NUM> may define a circumferential length around an outer surface of the inner layer <NUM> between the opposing sides or faces of the cut <NUM>. Similarly, for example, as viewed along the central longitudinal axis <NUM>, the outer layer <NUM> may develop a gap <NUM> (e.g., a space, etc.) from one radial point to another radial point, which may be referred to as a gap angle between opposing sides or faces of the cut <NUM>. The outer layer <NUM> may define a circumferential length around an outer surface of the outer layer <NUM> between the opposing sides or faces of the cut <NUM>. In some embodiments, the inner layer <NUM> and/or the outer layer <NUM> may be arranged in opposing clamshell configurations. For example, as viewed along the central longitudinal axis <NUM> in <FIG>, the inner layer <NUM> may open with the gap <NUM> to the right and the outer layer <NUM> may open with the gap <NUM> to the left. This is merely an example, and other configurations and/or arrangements are also possible.

Numerous other configurations, alternative embodiments, and/or additional features are also contemplated. For example, as shown in <FIG>, the faces of the cut <NUM> of the outer layer <NUM> may include rounded, tapered, and/or chamfered corners or edges, and/or the faces of the cut <NUM> of the inner layer <NUM> may include rounded, tapered, and/or chamfered corners or edges.

In another example, and as shown in <FIG>, the tubular member <NUM> and/or the distal section <NUM> may include an elastomeric outer sheath <NUM> disposed on, against, around, and/or about the outer layer <NUM>. The outer sheath <NUM> may be formed from a substantially elastic material, and may be configured to resiliently radially expand with the tubular member <NUM> and/or the distal section <NUM> without compromising its circumferential continuity. In some embodiments, the outer layer <NUM> may be disposed in sliding contact and/or engagement with the outer sheath <NUM>, and at least a portion of the outer layer <NUM> may be configured to move circumferentially relative to the outer sheath <NUM> when shifting between the unexpanded configuration, the partially expanded configuration, and/or the fully expanded configuration. The outer sheath <NUM> may be included with any configuration of the tubular member <NUM> and/or the distal section <NUM> illustrated herein, as well as others, and is not limited only to embodiments having rounded, tapered, and/or chamfered corners or edges of the cut(s) <NUM>/<NUM>.

In another example, and as shown in <FIG> and <FIG>, the inner layer <NUM> may be secured to the outer layer <NUM> such that at least a second portion of the inner layer <NUM> is circumferentially immovable and/or fixed in place relative to the outer layer <NUM>. In the example illustrated in <FIG>, a portion of the inner layer <NUM> may be secured to the outer layer <NUM> by a bonding agent <NUM> (e.g., an adhesive, an epoxy, a glue, etc.) configured to fixedly secure and/or attach the inner layer <NUM> to the outer layer <NUM>. The bonding agent <NUM> may be included with any configuration of the tubular member <NUM> and/or the distal section <NUM> illustrated herein, as well as others, and is not limited only to embodiments having rounded, tapered, and/or chamfered corners or edges of the cut(s) <NUM>/<NUM>. In the example illustrated in <FIG>, the outer layer <NUM> includes a projection <NUM> extending radially inwardly and the inner layer <NUM> includes a recess <NUM> configured to receive the projection <NUM> to form a key structure <NUM>. In at least some embodiments, the projection <NUM> may be integrally formed with the outer layer <NUM> as a single structure. In at least some embodiments, the recess <NUM> may be integrally formed with the inner layer <NUM> as a single structure. The key structure <NUM>, when the projection <NUM> is engaged with the recess <NUM>, may secure the inner layer <NUM> to the outer layer <NUM> such that at least a second portion of the inner layer <NUM> is circumferentially immovable and/or fixed in place relative to the outer layer <NUM>. In some embodiments, a mechanical fixation element (e.g., a screw, a rivet, a pin, etc.) may also be used, either in place of or in conjunction with, the bonding agent <NUM> and/or the key structure <NUM>. The projection <NUM>, the recess <NUM>, and/or the key structure 66may be included with any configuration of the tubular member <NUM> and/or the distal section <NUM> illustrated herein, as well as others, and is not limited only to embodiments having rounded, tapered, and/or chamfered corners or edges of the cut(s) <NUM>/<NUM>. Some suitable but non-limiting materials for the projection <NUM>, the recess <NUM>, and/or the key structure <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

In some embodiments, the inner layer <NUM> and/or the outer layer <NUM> may be configured to radially expand when subjected to a radially outward force from within the lumen <NUM>. In some embodiments, the inner layer <NUM> and/or the outer layer <NUM> may have no radially outward self-bias. For example, the tubular member <NUM>, the distal section <NUM>, the inner layer <NUM>, and/or the outer layer <NUM> may include no means or mechanism to radially expand and/or open on its own (e.g., absent a radially outward force exerted upon the inner layer <NUM> from within the lumen <NUM>). Instead, the tubular member <NUM>, the distal section <NUM>, the inner layer <NUM>, and/or the outer layer <NUM> may require a device (e.g., a medical device, a replacement heart valve delivery system, etc.) to be disposed within the lumen <NUM> to shift the introducer sheath <NUM>, the tubular member <NUM>, and/or the distal section <NUM> from the unexpanded configuration toward the partially expanded configuration and/or the fully expanded configuration.

In some embodiments, the inner layer <NUM> and/or the outer layer <NUM> may be biased radially inwardly toward the unexpanded configuration. In some embodiments, the inner layer <NUM> and/or the outer layer <NUM> may be self-biased radially inwardly toward the unexpanded configuration, and in the absence of any device or force pushing radially outward from within the lumen <NUM>, the tubular member <NUM> and/or the distal section <NUM> may radially collapse and/or return to the unexpanded configuration.

In some embodiments, the inner layer <NUM> and/or the outer layer <NUM> may be formed from a substantially inelastic material, wherein the inner layer <NUM> and/or the outer layer <NUM> are substantially unable to "stretch". For example, when the tubular member <NUM>, the distal section <NUM>, inner layer <NUM>, and/or the outer layer <NUM> is subjected to a radially outward force from within the lumen <NUM> and the first portion of the inner layer <NUM> correspondingly moves (e.g., slides, rotates, etc.) circumferentially relative to the outer layer <NUM>, the circumferential length of the outer layer <NUM> and/or the inner layer <NUM> (as measured circumferentially along an outer surface of the outer layer <NUM> and the inner layer <NUM>, respectively) stays constant while an inner diameter and/or inner extent of the lumen <NUM>, the inner layer <NUM>, and/or the outer layer <NUM> increases. As such, the inner layer <NUM> and/or the outer layer <NUM> may be configured to resiliently flex a small amount sufficient to allow an inner diameter and/or inner extent of the lumen <NUM>, the inner layer <NUM>, and/or the outer layer <NUM> to increase without stretching the inner layer <NUM> and/or the outer layer <NUM> to a larger circumferential length. Described another way, when the tubular member <NUM>, the distal section <NUM>, inner layer <NUM>, and/or the outer layer <NUM> is subjected to a radially outward force from within the lumen <NUM> and the first portion of the inner layer <NUM> correspondingly moves (e.g., slides, rotates, etc.) circumferentially relative to the outer layer <NUM>, the gap <NUM> and/or the gap angle of the outer layer <NUM> and the gap <NUM> and/or the gap angle of the inner layer <NUM> may increase while the circumferential length around each layer between opposing sides or faces of the cut <NUM> of the outer layer and the cut <NUM> of the inner layer remains constant. Similarly, a thickness of a wall of the inner layer <NUM> extending from an inner surface of the inner layer <NUM> to an outer surface of the inner layer <NUM> may remain substantially constant, and a thickness of a wall of the outer layer <NUM> extending from an inner surface of the outer layer <NUM> to an outer surface of the outer layer <NUM> may remain substantially constant, regardless of which configuration (e.g., the unexpanded configuration, the partially expanded configuration, the fully expanded configuration, etc.) the introducer sheath <NUM>, the tubular member <NUM>, and/or the distal section <NUM> is in.

In embodiments having the outer sheath <NUM>, the outer sheath <NUM> may be formed from a substantially elastic material, and therefore the outer sheath <NUM> may be configured to stretch and/or increase its circumferential length as the inner diameter and/or inner extent of the lumen <NUM> increases. However, in these embodiments, the inner layer <NUM> and/or the outer layer <NUM> may function as described above, with the circumferential length of each remaining constant as the inner diameter and/or inner extent of the lumen <NUM> increases. Some suitable but non-limiting materials for the outer sheath <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

In accordance with the invention, some aspects of another example configuration of the introducer sheath <NUM> are shown in <FIG>. In this example, the tubular member <NUM> comprises an inner layer and an outer layer <NUM> coaxially disposed about the central longitudinal axis <NUM> of the introducer sheath <NUM>, wherein the introducer sheath <NUM>, the tubular member <NUM>, and/or the distal section <NUM> is configured to shift between an unexpanded configuration (e.g., <FIG>), a partially expanded configuration (e.g. <FIG>), and a fully expanded configuration (e.g., <FIG>). The inner layer includes a plurality of longitudinally-oriented elements <NUM>, wherein the plurality of longitudinally-oriented elements <NUM> at least partially circumferentially overlap each other in the unexpanded configuration by an overlap amount <NUM>. The plurality of longitudinally-oriented elements <NUM> circumferentially overlap each other less as the tubular member <NUM> shifts from the unexpanded configuration toward the fully expanded configuration. For example, in the partially expanded configuration, the overlap amount <NUM> is reduced compared to the unexpanded configuration, as seen in <FIG>. The plurality of longitudinally-oriented elements <NUM> are circumferentially spaced apart from each other by a gap <NUM> (e.g., a space, etc.) in the fully expanded configuration, as seen in <FIG>.

In the example configuration of <FIG>, the outer layer <NUM> may be circumferentially continuous along its entire length. For example, the outer layer <NUM> may completely surround the inner layer, the plurality of longitudinally-oriented elements <NUM>, and/or the lumen <NUM>. Accordingly, the outer layer <NUM> may be formed from a substantially elastic material and therefore the outer layer <NUM> may be configured to stretch and/or increase its circumferential length (e.g., circumference) as the inner diameter and/or inner extent of the lumen <NUM> increases and/or as the plurality of longitudinally-oriented elements <NUM> circumferentially overlap each other less as the tubular member <NUM> shifts from the unexpanded configuration toward the fully expanded configuration. Some suitable but non-limiting materials for the outer layer <NUM> and/or the plurality of longitudinally-oriented elements <NUM>, for example metallic materials, polymer materials, composite materials, etc., are described below.

Further, it is contemplated that the inner surface and/or outer surface of the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM> (e.g., the proximal section <NUM>, the distal section <NUM> and variations of the distal section <NUM> described herein, the lumen <NUM>, etc.) may include one or more layers and/or coatings, such as a lubricious coating, a hydrophilic coating, a hydrophobic coating, or other suitable coatings, and the like, or may include a lubricant disposed thereon. Some suitable but non-limiting examples of layers and/or coatings are described below.

<FIG> illustrates an example replacement heart valve delivery system <NUM>. Numerous configurations of replacement heart valve delivery systems are contemplated for use with the introducer sheath <NUM>. The exemplary replacement heart valve delivery system <NUM> includes a delivery sheath <NUM> having a lumen extending through the delivery sheath <NUM>, and an elongated inner member <NUM> disposed within the lumen of the delivery sheath <NUM>, wherein the inner member <NUM> and the delivery sheath <NUM> are longitudinally slidable relative to each other. A replacement heart valve implant <NUM> may be disposed within a distal portion of the lumen of the delivery sheath <NUM> in a collapsed delivery configuration. The replacement heart valve implant <NUM> may be configured to expand to a deployed configuration when unconstrained by the delivery sheath <NUM> and/or when actuated to the deployed configuration after releasing the replacement heart valve implant <NUM> from the delivery sheath <NUM>. The replacement heart valve delivery system <NUM> may include a handle <NUM> attached to a proximal end of the delivery sheath <NUM> and/or the inner member <NUM>. The handle <NUM> may be operatively connected to the replacement heart valve implant <NUM> and/or may be configured to actuate the replacement heart valve implant <NUM> between the collapsed delivery configuration and the deployed configuration. Other configurations are also contemplated, and other medical devices may also be used in connection with the introducer sheath <NUM>.

<FIG> illustrate aspects of an example, non-claimed method of use of the introducer sheath <NUM> and/or a medical device system comprising the introducer sheath <NUM> and the replacement heart valve delivery system <NUM>. In some embodiments, the replacement heart valve delivery system <NUM> may be configured to slide within the lumen <NUM> of the introducer sheath <NUM> for advancement within a vasculature (e.g., an artery, a vein, the aorta <NUM>, the abdominal aorta, the femoral artery, etc.). In some embodiments, a method of delivering a medical device and/or a replacement heart valve, not forming part of the claimed invention, may include advancing the introducer sheath <NUM> through the vasculature (e.g., an artery, a vein, the aorta <NUM>, the abdominal aorta, the femoral artery, etc.) to an access site (e.g., the femoral artery, the common iliac, the abdominal aorta, the aorta <NUM>, the aortic arch <NUM>, etc.) and/or adjacent to a treatment site (e.g., a heart <NUM>, the aortic valve <NUM>, the mitral valve, etc.). For example, in some embodiments, a distal end of the introducer sheath <NUM> may be positioned within the abdominal aorta and/or in a position superior of the common iliac. In some embodiments, a method of delivering a medical device and/or a replacement heart valve, not forming part of the claimed invention, may include advancing the introducer sheath <NUM> through the vasculature (e.g., an artery, a vein, the aorta <NUM>, the abdominal aorta, the femoral artery, etc.) to the treatment site (e.g., a heart <NUM>, the aortic valve <NUM>, the mitral valve, etc.) and/or adjacent to the treatment site (e.g., a heart <NUM>, the aortic valve <NUM>, the mitral valve, etc.). For example, in some embodiments, the distal end of the introducer sheath <NUM> may be positioned within the aortic arch <NUM> or another position further superior of the common iliac than that discussed above.

In some embodiments, the medical device system may include a guidewire <NUM>. In some embodiments, the introducer sheath <NUM> may be disposed about and/or inserted or advanced over the guidewire <NUM>, as seen in <FIG>, although the guidewire <NUM> is not necessarily required in each embodiment. In some embodiments, the guidewire <NUM> may be inserted and advanced to the treatment site (e.g., the heart <NUM>, the aortic valve <NUM>, the mitral valve, etc.) before the introducer sheath <NUM> is inserted and/or advanced through the vasculature (e.g., an artery, a vein, the aorta <NUM>, the abdominal aorta, the femoral artery, etc.). In some embodiments, for example when treating the aortic valve <NUM>, the guidewire <NUM> may be inserted and/or advancing or navigated through the aortic valve <NUM> and into a left ventricle of the heart <NUM>. The introducer sheath <NUM> may then be advanced over the guidewire <NUM> until a distal end of the introducer sheath <NUM> is positioned at the access site (e.g., the femoral artery, the common iliac, the abdominal aorta, the aorta <NUM>, the aortic arch <NUM>, etc.) and/or adjacent to the treatment site (e.g., a heart <NUM>, the aortic valve <NUM>, the mitral valve, etc.).

The method may include inserting the replacement heart valve delivery system <NUM> into the lumen <NUM> of the introducer sheath <NUM>, and advancing the replacement heart valve delivery system <NUM> through the lumen of the introducer sheath <NUM> past the access site (e.g., the femoral artery, the common iliac, the abdominal aorta, the aorta <NUM>, the aortic arch <NUM>, etc.) to the treatment site (e.g., the heart <NUM>, the aortic valve <NUM>, the mitral valve, etc.), as seen in <FIG> for example. In some embodiments, the replacement heart valve delivery system <NUM> may be advanced over the guidewire <NUM>. The introducer sheath <NUM> may radially expand as the replacement heart valve delivery system <NUM> is advanced through the lumen <NUM> of the introducer sheath <NUM>. For example, the inner layer <NUM> may be circumferentially discontinuous along at least a portion of its length and at least the first portion of the inner layer <NUM> is configured to move circumferentially relative to the outer layer <NUM> when the introducer sheath <NUM> radially expands from the unexpanded configuration toward the fully expanded configuration as the replacement heart valve delivery system <NUM> is advanced through the lumen <NUM> of the introducer sheath <NUM>.

Regardless of the embodiment of the introducer sheath <NUM> used, the replacement heart valve delivery system <NUM> may be and/or remain unexposed to the vasculature (e.g., an artery, a vein, the aorta <NUM>, the abdominal aorta, the femoral artery, etc.) while the replacement heart valve delivery system <NUM> is disposed within the lumen <NUM> of the introducer sheath <NUM> and/or until a portion of the replacement heart valve delivery system <NUM> is disposed distally of the distal end of the introducer sheath <NUM>. In some embodiments, the inner layer <NUM> and the outer layer <NUM> circumferentially overlap such that when the introducer sheath <NUM> radially expands as the replacement heart valve delivery system <NUM> is advanced through the lumen <NUM> of the introducer sheath <NUM>, the lumen <NUM> of the introducer sheath <NUM> remains circumferentially closed to the vasculature (e.g., an artery, a vein, the aorta <NUM>, the abdominal aorta, the femoral artery, etc.).

The method may include deploying the replacement heart valve implant <NUM> at the treatment site (e.g., the heart <NUM>, the aortic valve <NUM>, the mitral valve, etc.), as seen in <FIG> for example. In some embodiments, the method may further include retracting the replacement heart valve delivery system <NUM> into the lumen <NUM> of the introducer sheath <NUM> and/or the tubular member <NUM>, and then withdrawing the replacement heart valve delivery system <NUM> and the introducer sheath <NUM> from the vasculature (e.g., an artery, a vein, the aorta <NUM>, the abdominal aorta, the femoral artery, etc.) together. In some embodiments, the replacement heart valve delivery system <NUM> may be retracted into the lumen <NUM> of the introducer sheath <NUM> and/or the tubular member <NUM> and completely withdrawn through the lumen <NUM> of the introducer sheath <NUM>, the hub member <NUM>, and/or the tubular member <NUM> before withdrawing and/or removing the introducer sheath <NUM> from the vasculature (e.g., an artery, a vein, the aorta <NUM>, the abdominal aorta, the femoral artery, etc.).

The materials that can be used for the various components of the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc. (and/or other systems or components disclosed herein) and the various elements thereof disclosed herein may include those commonly associated with medical devices. For simplicity purposes, the following discussion makes reference to the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc. However, this is not intended to limit the devices and methods described herein, as the discussion may be applied to other elements, members, components, or devices disclosed herein, such as, but not limited to, the coil member, the delivery sheath <NUM>, the inner member <NUM>, the replacement heart valve implant <NUM>, the handle <NUM>, etc. and/or elements or components thereof.

In some embodiments, the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc., and/or components thereof may be made from a metal, metal alloy, polymer (some examples of which are disclosed below), a metal-polymer composite, ceramics, combinations thereof, and the like, or other suitable material. Some examples of suitable metals and metal alloys include stainless steel, such as 444V, <NUM>, and 314LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® <NUM>, UNS: N06022 such as HASTELLOY® C-<NUM>®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® <NUM>, NICKELVAC® <NUM>, NICORROS® <NUM>, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R44035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R44003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; platinum; palladium; gold; combinations thereof; and the like; or any other suitable material.

In at least some embodiments, portions or all of the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc., and/or components thereof, may also be doped with, made of, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids a user in determining the location of the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloy, polymer material loaded with a radiopaque filler, and the like. Additionally, other radiopaque marker bands and/or coils may also be incorporated into the design of the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc. to achieve the same result.

In some embodiments, a degree of Magnetic Resonance Imaging (MRI) compatibility is imparted into the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc. For example, the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc., and/or components or portions thereof, may be made of a material that does not substantially distort the image and create substantial artifacts (e.g., gaps in the image). Certain ferromagnetic materials, for example, may not be suitable because they may create artifacts in an MRI image. The introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc., or portions thereof, may also be made from a material that the MRI machine can image. Some materials that exhibit these characteristics include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R44003 such as ELGILOYO, PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R44035 such as MP35-N® and the like), nitinol, and the like, and others.

In some embodiments, the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc., and/or portions thereof, may be made from or include a polymer or other suitable material. Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane (for example, Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-<NUM> (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS 50A), polycarbonates, ionomers, polyurethane silicone copolymers (for example, ElastEon® from Aortech Biomaterials or ChronoSil® from AdvanSource Biomaterials), biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like. In some embodiments, the sheath can be blended with a liquid crystal polymer (LCP). For example, the mixture can contain up to about <NUM> percent LCP.

In some embodiments, the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc. may include a textile material. Some examples of suitable textile materials may include synthetic yarns that may be flat, shaped, twisted, textured, pre-shrunk or un-shrunk. Synthetic biocompatible yarns suitable for use in the present invention include, but are not limited to, polyesters, including polyethylene terephthalate (PET) polyesters, polypropylenes, polyethylenes, polyurethanes, polyolefins, polyvinyls, polymethylacetates, polyamides, naphthalene dicarboxylene derivatives, natural silk, and polytetrafluoroethylenes. Moreover, at least one of the synthetic yarns may be a metallic yarn or a glass or ceramic yarn or fiber. Useful metallic yarns include those yarns made from or containing stainless steel, platinum, gold, titanium, tantalum or a Ni-Co-Cr-based alloy. The yarns may further include carbon, glass or ceramic fibers. Desirably, the yarns are made from thermoplastic materials including, but not limited to, polyesters, polypropylenes, polyethylenes, polyurethanes, polynaphthalenes, polytetrafluoroethylenes, and the like. The yarns may be of the multifilament, monofilament, or spun-types. The type and denier of the yarn chosen may be selected in a manner which forms a biocompatible and implantable prosthesis and, more particularly, a vascular structure having desirable properties.

In some embodiments, the introducer sheath <NUM>, the hub member <NUM>, the tubular member <NUM>, the proximal section <NUM>, the distal section <NUM>, the tapered region <NUM>, the outer layer <NUM>, the inner layer <NUM>, the outer sheath <NUM>, the outer layer <NUM>, the plurality of longitudinally-oriented elements <NUM>, the replacement heart valve delivery system <NUM>, the guidewire <NUM>, etc. may include and/or be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents may include antithrombogenic agents (such as heparin, heparin derivatives, urokinase, and PPack (dextrophenylalanine proline arginine chloromethylketone)); anti-proliferative agents (such as enoxaparin, angiopeptin, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory agents (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine); antineoplastic/antiproliferative/anti-mitotic agents (such as paclitaxel, <NUM>-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin and thymidine kinase inhibitors); anesthetic agents (such as lidocaine, bupivacaine, and ropivacaine); anti-coagulants (such as D-Phe-Pro-Arg chloromethyl keton, an RGD peptide-containing compound, heparin, anti-thrombin compounds, platelet receptor antagonists, anti-thrombin antibodies, anti-platelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick antiplatelet peptides); vascular cell growth promoters (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional activators, and translational promoters); vascular cell growth inhibitors (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional repressors, translational repressors, replication inhibitors, inhibitory antibodies, antibodies directed against growth factors, bifunctional molecules consisting of a growth factor and a cytotoxin, bifunctional molecules consisting of an antibody and a cytotoxin); cholesterol-lowering agents; vasodilating agents; and agents which interfere with endogenous vascoactive mechanisms.

Claim 1:
A medical radially expandable introducer sheath (<NUM>), comprising:
a tubular member (<NUM>) comprising an inner layer (<NUM>) and an outer layer (<NUM>, <NUM>) coaxially disposed about a central longitudinal axis (<NUM>) of the introducer sheath (<NUM>), the tubular member (<NUM>) being configured to shift between an unexpanded configuration to an expanded configuration;
wherein the inner layer (<NUM>) is circumferentially discontinuous along at least a portion of its length;
wherein at least a first portion of the inner layer (<NUM>) is configured to move circumferentially relative to the outer layer (<NUM>, <NUM>) when shifting between the unexpanded and expanded configurations,
wherein the inner layer (<NUM>) comprises a plurality of longitudinally-oriented elements (<NUM>), wherein the plurality of longitudinally-oriented elements (<NUM>) at least partially circumferentially overlap each other in the unexpanded configuration,
wherein the plurality of longitudinally-oriented elements (<NUM>) circumferentially overlap each other less as the tubular member (<NUM>) shifts from the unexpanded configuration toward the expanded configuration,
characterized in that
the plurality of longitudinally-oriented elements (<NUM>) is circumferentially spaced apart from each other in the expanded configuration.