Patent Description:
In some instances, performing percutaneous medical procedures may require the insertion and/or maneuvering of relatively large medical devices through a patient's 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 the vasculature, it may make undesirable contact with one or more vessel walls. This interference may cause injury to the vessel as the medical device is navigated into calcified or diseased vessels. Therefore, in some instances an introducer is 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).

<CIT> discloses an elastic introducer sheath, which can locally expand and reduce to accommodate a transcatheter medical device. <CIT> discloses an expandable introducer sheath configured to radially expand as a medical device is axially advanced or retracted through the introducer sheath.

The present invention is directed to an introducer as set forth in the appended claims. The introducer in accordance with the invention includes an inner liner including a lumen, a proximal region, and at least one folded portion extending longitudinally along the proximal region. The introducer further includes an expandable support member. The support member includes a spine extending along the length of the support member and a plurality of ribs extending along a length of the support member, the plurality of ribs including a first set of rib members and a second set of rib members. The introducer further includes a sheath attached to at least a portion of the support member. The support member is designed to shift from a first position in which the first set of rib members interdigitate with the second set of rib members to an expanded position in which the first set of rib members and the second set of rib members radially separate from one another. The spine is attached to the sheath and the plurality of ribs are free to move relative to the liner, the sheath or both the liner and the sheath.

Alternatively or additionally to any of the examples above, wherein the expandable support member extends around at least a portion of the inner liner.

Alternatively or additionally to any of the examples above, wherein the support member is positioned between the inner liner and the sheath.

Alternatively or additionally to any of the examples above, wherein the at least one folded portion allows the inner liner to radially expand.

Alternatively or additionally to any of the examples above, wherein the at least one folded portion extends along at least a portion of an inner surface of the support member.

Alternatively or additionally to any of the examples above, wherein at least a portion of the sheath is configured to expand as the at least one folded portion radially expands.

Alternatively or additionally to any of the examples above, wherein the first set of rib elements are attached to a first lateral edge of the spine, and wherein the second set of rib elements are attached to a second lateral edge of the spine.

Alternatively or additionally to any of the examples above, the first set of rib members attached to the spine, wherein each of the first set of rib members extends outward from the spine in a first direction; and the second set of rib members attached to the spine, wherein each of the second set of rib members extends outward from the spine in a second direction different than the first direction.

Alternatively or additionally to any of the examples above, wherein the first and second sets of rib members wrap around at least a portion of the inner liner.

Alternatively or additionally to any of the examples above, wherein the first and second sets of rib members are positioned between the inner liner and the sheath.

Alternatively or additionally to any of the examples above, wherein the first and second set of rib members are free to move relative to the liner, the sheath, or both the liner and the sheath.

The above summary of some examples is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The Figures and Detailed Description, which follow, more particularly exemplify these examples.

It should be understood, however, that the intention is not to limit the disclosure to the particular examples described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

The present invention is directed to an introducer as set forth in the appended claims.

It is noted that references in the specification to "an embodiment", "some examples", "other examples", etc., indicate that the embodiment described may include one or more particular features, structures, and/or characteristics. However, such recitations do not necessarily mean that all examples include the particular features, structures, and/or characteristics. Additionally, when particular features, structures, and/or characteristics are described in connection with one embodiment, it should be understood that such features, structures, and/or characteristics may also be used connection with other examples whether or not explicitly described unless clearly stated to the contrary.

The drawings, which are not necessarily to scale, depict illustrative examples and are not intended to limit the scope of the disclosure.

The following examples disclose an intravascular medical device including an expandable introducer, whereby the introducer is designed to expand from a reduced profile, unexpanded configuration to an expanded configuration.

<FIG> illustrates an example expandable introducer (e.g., delivery sheath, access sheath, etc.) <NUM> in accordance with the invention. The introducer may include a first expandable portion <NUM>, a second expandable portion <NUM> and a hub <NUM>. As shown in <FIG>, second expandable portion <NUM> may be positioned between hub <NUM> and first expandable portion <NUM>. A proximal region <NUM> of second expandable portion <NUM> may be attached to hub <NUM>, while a distal region <NUM> of second expandable portion <NUM> may be positioned adjacent a proximal portion of first expandable portion <NUM>.

Additionally, introducer <NUM> further includes an elongated compliant liner (e.g., tubular membrane, etc.) <NUM> having a lumen <NUM>, proximal portion <NUM> and a distal portion <NUM>. Liner <NUM> may extend along both first expandable portion <NUM> and second expandable portion <NUM>. The introducer <NUM> also includes an outer sheath <NUM>. Sheath <NUM> may extend along (e.g., cover) both first expandable portion <NUM> and second expandable portion <NUM>. As illustrated in <FIG>, second expandable section <NUM> may include a ribcage <NUM>. Ribcage <NUM> may extend from the proximal region <NUM> of the second expandable portion <NUM> to the distal region <NUM> of the second expandable portion <NUM>. Further, ribcage <NUM> includes a first set of rib members <NUM> positioned adjacent (e.g., interdigitated with) a second set of rib members <NUM>. Additionally, first expandable section <NUM> may include a spine member <NUM>. Spine member <NUM> may include reinforcement members <NUM>.

<FIG> further illustrates that first expandable portion <NUM> may include a first outer diameter "D<NUM>" and the second expandable portion <NUM> may include an outer diameter "D<NUM>. " In some instances, diameter D<NUM> may be equal to diameter D<NUM>. In other words, introducer <NUM> may have a substantially constant diameter along both first expandable portion <NUM> and second expandable portion <NUM>.

In other instances, diameter D<NUM> may be different from diameter D<NUM>. For example, D<NUM> may be larger than D<NUM>. Specifically, D<NUM> may be <NUM>-<NUM>% larger than D<NUM>, or D<NUM> may be <NUM>%-<NUM>% larger than D<NUM>, or D<NUM> may be <NUM>%-<NUM>% larger than D<NUM>, or D<NUM> may be <NUM>%-<NUM>% larger than D<NUM>, or D<NUM> may be more than <NUM>% larger than D<NUM>. Additionally, in some other examples, diameter D<NUM> may be larger than D<NUM>. For example, D<NUM> may be <NUM>-<NUM>% larger than D<NUM>, or D<NUM> may be <NUM>%-<NUM>% larger than D<NUM>, or D<NUM> may be <NUM>%-<NUM>% larger than D<NUM>, or D<NUM> may be <NUM>%-<NUM>% larger than D<NUM>, or D<NUM> may be more than <NUM>% larger than D<NUM>.

Further, introducer <NUM> may include one or more tapered regions (not shown). For example, a tapered region may be positioned along either second expandable portion <NUM> and/or first expandable portion <NUM> of introducer <NUM>. In some examples, at least a portion of first expandable portion <NUM> of introducer <NUM> may have a substantially constant outer diameter which transitions into tapered portion. Similarly, in some examples, at least a portion of second expandable portion <NUM> of introducer <NUM> may have a substantially constant outer diameter which transitions into tapered portion. However, this is not intended to be limiting. It is contemplated that any portion of the introducer <NUM> may include any number of tapers, constant diameter regions or combinations thereof.

In some examples, the proximal portion <NUM> of liner <NUM> and/or sheath <NUM> may be attached to hub <NUM>. Further, liner <NUM> may extend along the inner surface of the spine member <NUM> (of first expandable section <NUM>) and/or the ribcage <NUM> (of second expandable section <NUM>). Additionally, in some examples sheath <NUM> may extend along the outer surface of spine member <NUM> and/or ribcage <NUM>. For example, in some instances, spine member <NUM> and/or ribcage <NUM> may be positioned between liner <NUM> and/or sheath <NUM>.

Additionally, in some instances the ribcage <NUM>, sheath <NUM> and/or liner (e.g., a combination of ribcage <NUM>, sheath <NUM> and/or liner <NUM>) may be attached to hub <NUM>. The hub <NUM> may include a hemostatic valve or seal disposed therein. The hemostatic valve or seal may prevent blood or other bodily fluid(s) from flowing proximally through the lumen <NUM> of liner <NUM>. In at least some examples, the hub <NUM> may include a port in fluid communication with the lumen <NUM> of liner <NUM>.

As discussed above, <FIG> illustrates outer sheath <NUM>, ribcage <NUM> and/or spine member (e.g., support member) <NUM> fixedly attached to liner <NUM>. As will be described in greater detail below, outer sheath <NUM>, ribcage <NUM> and/or spine <NUM> may be disposed (e.g., attached) along a portion of liner <NUM> from distal portion <NUM> to proximal portion <NUM>. In some examples, outer sheath <NUM> may include one or more apertures (e.g., openings) <NUM> extending through at least a portion of the wall thickness of sheath <NUM>. As shown in <FIG>, the one or more apertures <NUM> may be aligned with one another along the central longitudinal axis <NUM> of introducer <NUM>. For example, <FIG> shows the one or more apertures <NUM> positioned along the first expandable portion <NUM>, whereby the one or more apertures <NUM> are aligned with the longitudinal axis <NUM> of the first expandable portion <NUM>. Additionally, apertures <NUM> may be positioned between adjacent reinforcement members <NUM>. For example, <FIG> shows apertures <NUM> positioned between two reinforcement members <NUM>. As will be described in greater detail below, the distal portion <NUM> of introducer <NUM> may include an atraumatic tip member <NUM>. The above discussion is not intended to be limiting. Rather, it is contemplated that the one or more apertures <NUM> may be located on any portion of introducer <NUM>.

Additionally, in some examples the distal portion <NUM> of ribcage <NUM> may be positioned adjacent the distal end of spine member <NUM>. As shown in the detailed view of <FIG>, the distal portion of spine member <NUM> may include a collar <NUM>. In some examples, one or more support members <NUM> may be attached to collar <NUM>. Further, as illustrated in <FIG>, collar <NUM> may abut a distal end <NUM> of ribcage <NUM>. In some instances, collar <NUM> may be attached to the distal end <NUM> of ribcage <NUM>. In yet other instances, collar <NUM> may overlap with the distal end of ribcage <NUM>. For example, while not illustrated in <FIG>, it can be appreciated that in some instances it may be desirable for collar <NUM> to be positioned overtop (e.g., overlap, extend around, cover, etc.) a portion of the distal portion <NUM> of ribcage <NUM>. In other words, in some instances it may be desirable for a portion of collar <NUM> to be positioned radially outward of the distal portion <NUM> of ribcage <NUM>.

While the above discussed include examples in which collar <NUM> is positioned radially outward a distal portion <NUM> of ribcage <NUM>, it is contemplated that the distal portion <NUM> of ribcage <NUM> may be positioned radially outward of collar <NUM>.

<FIG> illustrates an example ribcage <NUM>. As shown in <FIG> and discussed above, ribcage <NUM> includes a first set of rib members <NUM> positioned adjacent (e.g., interdigitated, interlaced, etc.) a second set of rib members <NUM>. Additionally, <FIG> illustrates that both the first set of rib members <NUM> and the second set of rib members <NUM> include a curved portion. Additionally, <FIG> further illustrates that the first set of rib members <NUM> and the second set of rib members <NUM> extend away from a central spine portion <NUM>. Specifically, the first set of rib members <NUM> extend away from the central spine portion <NUM> in a clockwise direction while the second set of rib members <NUM> extend away from the central spine portion <NUM> in a counterclockwise direction. In some instances, first set of rib members <NUM> may be described as extending away from a first lateral edge <NUM> of central spine member <NUM> and the second set of rib members <NUM> may be described as extending away from a second lateral edge <NUM> of central spine member <NUM>. Further, while first set of rib members <NUM> and second set of rib members <NUM> extend away from the first lateral edge <NUM> and second lateral edge <NUM> of spine member <NUM>, they eventually begin to curve back toward and interdigitate with one another. As shown in <FIG>, the curved shape of both first set of rib members <NUM> and second set of rib members <NUM> forms a lumen <NUM>. Lumen <NUM> may include a diameter depicted as "D<NUM>" in <FIG>. As will be discussed in greater detail below, liner <NUM> may extend within lumen <NUM>.

In accordance with the invention, ribcage <NUM> is able to shift (e.g., radially expand) from a non-expanded configuration (such as that shown in <FIG>) to an expandable configuration shown in <FIG>. Specifically, the diameter of lumen <NUM> shown in <FIG> (depicted as diameter D<NUM>) may increase to define a larger diameter (depicted as "D<NUM>" in <FIG>). Further, <FIG> illustrates in accordance with the invention that as ribcage <NUM> expands, the first set of rib members <NUM> and the second set of rib members <NUM> radially separate from one another. <FIG> depicts the radial separation of the first set of rib members <NUM> from the second set of rib members <NUM> via a plurality of double-ended arrows. The tips of the double-ended arrows shown in <FIG> represent the radial separation between the ends of each of the first set of rib members <NUM> and the second set of rib members <NUM>, respectively.

<FIG> shows an example step in manufacturing introducer <NUM>. <FIG> shows liner <NUM> (discussed above with respect to <FIG>) having a substantially annular shape and a lumen <NUM> extending at least partially therethrough. In some examples, the lumen <NUM> may extend from a proximal end <NUM> of liner <NUM> to a distal end <NUM> of liner <NUM>. Additionally, the lumen <NUM> may extend completely through an entire length of liner <NUM>. It is contemplated that other shapes and/or configurations are possible within the scope of the present disclosure, as will be apparent from the discussion below, and other shapes or configurations discussed herein may be used in the configuration(s) schematically shown in the FIGs.

As stated above, liner <NUM> may be described as having a compliant elongated tubular structure having a lumen <NUM> extending therethrough from proximal end <NUM> to a distal end <NUM>. Liner <NUM> may include a wall having an inner surface and an outer surface. In some examples, a thickness of the wall may be defined by the inner surface and the outer surface.

In some examples, liner <NUM> and/or lumen <NUM> may be configured to radially expand from a delivery configuration to an expanded configuration when subjected to a radially outward force from within the lumen <NUM> and/or liner <NUM>. In at least some examples, liner <NUM> may be substantially or completely compliant and/or liner <NUM> may have no radial self-bias - that is, no radially inward self-bias and/or no radially outward self-bias. In other words, liner <NUM> may be non-self-supporting and may not include a mechanism to radially expand and/or open on its own, such as absent a radially outward force exerted upon liner <NUM>. Instead, liner <NUM> may require a device or object that has a greater outer diameter than an inner diameter of lumen <NUM> and/or liner <NUM> to be disposed within lumen <NUM> to push and/or force liner <NUM> radially outward toward the expanded configuration.

Additionally, liner <NUM> may not require a radially inward force be applied upon itself to collapse itself inward when there is no device, object, etc. disposed within lumen <NUM>. In other words, liner <NUM> may not be held open or maintain a particular expanded size on its own, or liner <NUM> may be non-self-supporting as mentioned above. Similarly, liner <NUM> may not be biased to collapse inwardly on its own. In other words, liner <NUM> may take the shape and/or form of surrounding tissue(s) after being expanded. For example, a constriction in or of a vessel or body lumen in which liner <NUM> is disposed may urge liner <NUM> radially inward, but liner <NUM> is not self-biased inwardly on its own, for example, liner <NUM> may have zero return force after expanding/opening.

In the delivery configuration, lumen <NUM> may have a first inner diameter defined by the inner surface of the wall of liner <NUM>. In some examples, as will be apparent herein, the first inner diameter may be defined as a first inner radial extent and/or distance from a central longitudinal axis <NUM> of liner <NUM> and/or the expandable introducer <NUM>. In the expanded configuration, lumen <NUM> may have a second inner diameter defined by the inner surface of the wall. In some examples, as will be apparent herein, the second inner diameter may instead be defined as a second inner radial extent and/or distance from a central longitudinal axis <NUM> of liner <NUM> and/or the expandable introducer <NUM>. In some examples, the second inner diameter may be greater than the first inner diameter. Similarly, the second inner radial extent may be greater than the first inner radial extent.

Similarly, liner <NUM> may have an outer diameter and/or outer radial extent defined by the outer surface of the wall of liner <NUM>. In the delivery configuration, liner <NUM> may have a first outer diameter and/or first outer radial extent defined by the outer surface of the wall. In the expanded configuration, liner <NUM> may have a second outer diameter and/or a second outer radial extent defined by the outer surface of the wall. In some examples, the second outer diameter may be greater than the first outer diameter. Similarly, the second outer radial extent may be greater than the first outer radial extent.

As discussed above, liner <NUM> includes one or more folds <NUM> formed therein in the delivery configuration. In some examples, the one or more folds <NUM> may include two folds, three folds, four folds, five folds, six folds, seven folds, eight folds, nine folds, ten folds, or another desirable number or quantity of folds. In at least some examples, liner <NUM> may be disposed radially inward of outer sheath <NUM>. In some examples, the one or more folds <NUM> may each fold back on themselves to form, for example, a wave shape, an S-shape, T-shape and/or a Z-shape when viewed in cross-section. In some examples, each of the one or more folds forming a T-shape may include two or more distinct waves, S-shaped, or Z-shaped secondary folds within and thus forming each of the one or more T-shaped folds. Other shapes and configurations, while not expressly illustrated, are also contemplated.

Additionally, in some examples, liner <NUM> may be configured to permit the lumen <NUM> to radially expand from the first inner diameter and/or the first inner radial extent to the second inner diameter and/or the second inner radial extent. In some examples, liner <NUM> is configured to substantially prevent axial stretching along the lumen <NUM>. In other words, liner <NUM> may permit the lumen <NUM> to expand radially outward from a central longitudinal axis <NUM> of liner <NUM> and/or the expandable introducer <NUM> without stretching or expanding in an axial or longitudinal direction. In some examples, the second inner diameter and/or the second inner radial extent may be greater than the first outer diameter and/or the first outer radial extent. Because liner <NUM> may be made from an inelastic material, it may be configured to expand radially outward to a predetermined maximum second inner diameter and/or a second inner radial extent, but may not stretch or expand radially outward beyond the predetermined maximum second inner diameter and/or second inner radial extent.

In some examples, the inner surface of the wall of liner <NUM> may include one or more layers or coatings, such as a lubricious coating, a hydrophilic coating, a hydrophobic coating, or other suitable coatings, and the like, or liner <NUM> may include a lubricant disposed within the lumen <NUM>. In some examples, an outer surface of the expandable introducer <NUM> and/or outer sheath <NUM> may include one or more layers or coatings, such as a lubricious coating, a hydrophilic coating, a hydrophobic coating, or other suitable coating, and the like, or the expandable introducer <NUM> and/or outer sheath <NUM> may include a lubricant disposed upon the outer surface thereof.

Additionally, <FIG> shows both ribcage <NUM> and spine member <NUM> positioned along the outer surface of liner <NUM>. Ribcage <NUM> may have the first set of rib members <NUM> and a second set of rib members <NUM> (discussed above) extending along an outer surface of liner <NUM>. Additionally, spine member <NUM> may have one or more reinforcement member <NUM> extending along an outer surface of liner <NUM>. In some instances, both ribcage <NUM> and/or spine member <NUM> may be positioned (e.g., attached, fused, glued, tacked, adhered, etc.) to the outer surface of liner <NUM> during the manufacturing process. For example, in some examples ribcage <NUM> and/or spine member <NUM> may be positioned on the outer surface of liner <NUM> prior to outer sheath <NUM> being positioned over the combination of liner <NUM> and outer sheath <NUM>.

<FIG> shows an example outer sheath <NUM>. In some examples, outer sheath <NUM> may be fixedly attached to at least a portion of the outer surface of liner <NUM>, ribcage <NUM> and/or spine <NUM>. Further, <FIG> shows outer sheath <NUM> including a proximal portion <NUM> and a distal portion <NUM>. In at least some examples disclosed herein, introducer <NUM> may be manufactured such that the distal portion <NUM> of sheath <NUM> may align with first expandable portion <NUM> (e.g., the distal portion <NUM> may extend overtop spine <NUM>) while the proximal portion <NUM> of sheath <NUM> may align with second expandable portion <NUM> (e.g., proximal portion may extend overtop ribcage <NUM>). Outer sheath <NUM> may be bonded, laminated, fused, glued, co-molded, melted, welded, or other suitable means, to a portion of liner <NUM>, ribcage <NUM> and/or spine <NUM>. In some examples, outer sheath <NUM> may be permanently attached to the outer surface of liner <NUM>.

In some examples, outer sheath <NUM> may be formed from a polymeric material, which may form at least a portion of a wall of outer sheath <NUM>. In some examples, outer sheath <NUM> may be formed from the same material as liner <NUM>. In some examples, outer sheath <NUM> may be formed from a different material than liner <NUM>. In some examples, some or all of outer sheath <NUM> may be fixedly attached to the outer surface of the wall of liner <NUM>. In some examples, the entire outer sheath <NUM> may be fixedly attached to the outer surface of the wall of liner <NUM>, ribcage <NUM> and/or spine <NUM>. However, as will be discussed in greater detail below, in some examples outer sheath <NUM> may be free from attachment to all or a portion of liner <NUM>, ribcage <NUM> and/or spine <NUM>.

In some examples, at least a portion of outer sheath <NUM> may extend continuously around a circumference of liner <NUM> in a first configuration. In some examples, at least a portion of outer sheath <NUM> may be discontinuous. As will be discussed in greater detail below, in some examples outer sheath <NUM> may include a plurality of apertures <NUM> (e.g., openings, cutouts, perforations, notches, holes, apertures, or other weakening features) formed in the wall of outer sheath <NUM> which effectively remove at least (or in some cases, only) a portion of the wall of outer sheath <NUM>. While apertures <NUM> shown in <FIG> are substantially hexagonal, it is contemplated that apertures <NUM> may be any shape. For example, apertures <NUM> may be circular, square, rectangular, ovular, triangular, diamond shaped, or the like.

In some examples, the plurality of apertures <NUM> formed in the wall of outer sheath <NUM> may be arranged in one or more longitudinal lines along the length of the expandable introducer <NUM>, liner <NUM>, and/or outer sheath <NUM>. As discussed above, apertures <NUM> may be positioned in distal portion <NUM> and thereby aligned with spine member <NUM> along first expandable portion <NUM>. Further, the plurality of apertures <NUM>, or other weakening features formed in the wall of outer sheath <NUM> may extend laterally and/or transversely through the wall of outer sheath <NUM> relative to the central longitudinal axis <NUM>. In some examples, a wall thickness of the outer sheath may be tapered about the circumference of liner <NUM> such that a reduced thickness region of outer sheath <NUM> is disposed adjacent to, radially outward of, in communication with, and/or directly over the one or more folds <NUM> of liner <NUM>.

Further, in some examples the apertures <NUM> included in outer sheath <NUM> may be spaced apart from one another. For example, <FIG> shows adjacent apertures <NUM> located near the distal end <NUM> of outer sheath <NUM> spaced apart from one another a distance "W". Similarly, <FIG> shows two other adjacent apertures <NUM> located near the proximal end <NUM> of outer sheath <NUM> spaced apart from one another a distance "Z". It can be appreciated that in some examples, distance "W" and distance "Z" may be equal. In other words, in some examples all the apertures <NUM> positioned along outer sheath <NUM> may be spaced equidistant from one another. However, in other examples, it can be appreciated that distances "W" and "Z" may be different. In other words, in some examples apertures <NUM> may include variable spacing between one another. For example, it can be appreciated that the spacing between apertures <NUM> may gradually increase from the distal portion <NUM> to the proximal portion <NUM> of outer sheath <NUM>.

Similarly, <FIG> illustrates the apertures <NUM> having a surface area. While the term surface area may be used to herein, the "surface area," of a given aperture <NUM> as described herein may be defined as the "area" bounded by the shape of a given aperture <NUM>. For example, in <FIG>, the surface area of a given aperture <NUM> may be defined as the area bounded by an individual hexagon. Further, <FIG> shows two different individual apertures <NUM> and <NUM>. Aperture <NUM> may be positioned near the distal end <NUM> of outer sheath <NUM> while aperture <NUM> may be positioned near the proximal end <NUM> of outer sheath <NUM>. In some examples, the surface area of the apertures <NUM> of outer sheath <NUM> may be equal. In other examples, such as that shown in <FIG>, the surface area of apertures <NUM> may be different. For example, the surface area of aperture <NUM> may be larger than that of aperture <NUM>. Further, the area of apertures <NUM> may decrease along outer sheath <NUM> from the distal portion <NUM> to the proximal portion <NUM>. Additionally, during the manufacturing process, it is contemplated that the size, shape and/or spacing between apertures <NUM> may change. For example, smaller apertures (e.g., aperture <NUM>) may expand as the proximal portion <NUM> of the outer sheath <NUM> may be pulled and/or stretched over the tapered portions of introducer <NUM>, for example. It is further contemplated that various arrangements, spacing, areas, surface areas and/or alignments of apertures <NUM> may be utilized in the design of outer sheath <NUM>.

<FIG> shows a cross-sectional view along line <NUM>-<NUM> of <FIG>. <FIG> depicts introducer <NUM> in an unexpanded configuration. Additionally, it can be appreciated that <FIG> represents a cross-section of the second expandable section <NUM> of introducer <NUM> after manufacturing (e.g., after heating and reflowing sheath <NUM>, for example).

<FIG> illustrates liner <NUM> including three folded sections <NUM> extending along the inner surface of liner <NUM>. While <FIG> shows three folded sections <NUM>, it is contemplated that liner <NUM> may include more or less than three folded sections <NUM>. For example, liner <NUM> may include <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more folded sections <NUM>. Further, <FIG> illustrates that a portion of ribcage <NUM> may attached (e.g., tacked, fused, integrated, engaged, etc.) with the tubular wall of outer sheath <NUM> at attachment location <NUM>. In other words, <FIG> illustrates that in some examples, a portion of outer sheath <NUM> and a portion of ribcage <NUM> may be manufactured (e.g., tacked/fused/melted/reflowed) such that they are attached together. Further, it can be appreciated that a portion of ribcage <NUM> may be attached (e.g., tacked, fused, integrated, etc.) with the tubular wall of outer sheath <NUM> along the longitudinal axis <NUM> of introducer <NUM>. In other words, it is contemplated that ribcage <NUM> may be attached to outer sheath <NUM> in a series of attachment locations <NUM> that are aligned with one another along the longitudinal axis <NUM> of introducer <NUM>. However, this is not intended to be limiting. Rather, it is contemplated that ribcage <NUM> may be attached to outer sheath <NUM> in a variety of different locations along the interface of outer sheath <NUM> and ribcage <NUM>.

As discussed above, ribcage <NUM> includes one or more first rib members <NUM> positioned adjacent to one or more second rib members <NUM>. <FIG> illustrates spine portion <NUM> (discussed above) extending longitudinally along the longitudinal axis of introducer <NUM>. In some examples, the attachment points <NUM> (discussed above) may be longitudinally aligned along the spine portion <NUM> of ribcage <NUM>. However, this is not intended to be limiting. It is contemplated that in some examples not in accordance with the invention, ribcage <NUM> is not attached to outer sheath <NUM>. It is further contemplated that any portion of ribcage <NUM> (including spine portion <NUM>) may be integral with all or a portion of outer sheath <NUM>.

<FIG> further illustrates first rib member <NUM> and second rib member <NUM> extending away from spine portion <NUM> in a clockwise direction and counterclockwise direction, respectively. As shown in <FIG>, both first rib member <NUM> and second rib member <NUM> include a curved portion which is positioned along the inner surface of sheath member <NUM>, whereby the curved portion of first rib member <NUM> extends away from spine portion <NUM> in a first direction (e.g., clockwise direction) and the second rib member <NUM> extends away from the spine portion <NUM> in a second direction (e.g., counterclockwise direction).

An example methodology to construct the introducer <NUM> (shown in <FIG>) may include configuring ribcage <NUM>, spine member <NUM>, outer sheath <NUM> and liner <NUM> as shown in <FIG> followed by applying heat such that outer sheath member melts (e.g., reflows) around ribcage <NUM> and/or liner <NUM>. It can be appreciated that liner <NUM> may be constructed from a material that has a higher melting point than either outer sheath <NUM> and/or ribcage <NUM>, and therefore, will not melt upon the application of heat sufficient to melt outer sheath <NUM> and/or ribcage <NUM> together. In other examples, liner <NUM> may be constructed from a non-thermoplastic material designed to resist melting while heat is applied to reflow outer sheath <NUM> and ribcage <NUM> together. Additionally, it is contemplated that arrangement of liner <NUM>, outer sheath <NUM> and ribcage <NUM> may include a variety of configurations throughout the manufacturing steps. For example, examples contemplated herein may include different positions, alignment, spacing, sizes, dimensions, etc. of ribcage <NUM>, liner <NUM> and/or sheath <NUM> relative to one another during the manufacturing process and/or final design.

<FIG> shows a cross-sectional view along line <NUM>-<NUM> of <FIG>. Similarly to that described with respect to <FIG>, <FIG> illustrates liner <NUM> including three folded sections <NUM> extending along the inner surface of liner <NUM> (as discussed above, liner <NUM>, included folded sections <NUM>, may span the length of both second expandable portion <NUM> and first expandable portion <NUM>). While <FIG> shows three folded sections <NUM>, it is contemplated that liner <NUM> may include greater or less than three folded sections <NUM>. For example, liner <NUM> may include <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more folded sections <NUM>.

Additionally, it can be appreciated that <FIG> represents the cross-section of introducer <NUM> after manufacturing. For example, <FIG> illustrates that spine <NUM> is incorporated into the tubular wall of outer sheath <NUM>. In other words, <FIG> illustrates that in some examples, outer sheath <NUM> and spine member <NUM> may be manufactured (e.g., melted/reflowed together) such that they form a unitary member. Similarly to that discussed with respect to folded members <NUM>, it can be appreciated that while <FIG> shows spine member <NUM> including three support members <NUM>, spine <NUM> may include greater or less than three support members <NUM>. For example, spine <NUM> may include <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more support members <NUM>.

As discussed above, in some instances outer sheath <NUM> may include one or more apertures <NUM> extending at least partially through the wall thickness of outer sheath <NUM>. The detailed view in <FIG> shows one example of an aperture <NUM> having extending partially through the tubular wall of outer sheath <NUM>. The reduced wall thickness of aperture <NUM> is depicted as thickness "X. " Further, a portion of the tubular wall of outer sheath <NUM> adjacent to aperture <NUM> is depicted as "Y. " It can be seen that the thickness "X" of aperture <NUM> is less than the thickness "Y. " As will be described in greater detail below, it can be appreciated that the reduced wall thickness "X" (as compared to wall thickness "Y") may create a preferential "tear point" within outer sheath <NUM>. In other words, aperture(s) <NUM> may define a perforated tear line extending along introducer <NUM>.

Additionally, in at least some examples, the apertures <NUM> (e.g., openings, cutouts, perforations, notches, holes) or other weakening features formed in the wall of the sheath <NUM> may be positioned adjacent to, radially outward of, in communication with, and/or directly over the one or more folds <NUM> formed in liner <NUM>. For example, <FIG> shows apertures <NUM> positioned directly over the one or more folds <NUM> in liner <NUM>. More particularly, in some instances apertures <NUM> may be aligned at a point along outer sheath <NUM> in which fold <NUM> begins to wrap underneath outer sheath <NUM>. It can be appreciated that the point at which aperture <NUM> is aligned with fold <NUM> may be the point at which fold <NUM> initially begins to separate when liner <NUM> shifts from the configuration shown in <FIG> to an expanded configuration.

Similarly to that described with respect to <FIG>, an example methodology to construct the introducer <NUM> may include configuring spine <NUM>, outer sheath <NUM> and liner <NUM> as shown in <FIG> (which depicts the introducer <NUM> in an intermediate state/configuration during the example manufacturing process) followed by applying heat such that outer sheath member <NUM> melts (e.g., reflows) and encapsulates spine member <NUM> as shown in <FIG> depicts the introducer shown in <FIG> after the application of heat and melting/reflow process). It can be appreciated that liner <NUM> may be constructed from a material that has a higher melting point than either outer sheath <NUM> or spine member <NUM>, and therefore, will not melt upon the application of heat sufficient to melt outer sheath <NUM> and/or spine member <NUM> together. In other examples, liner <NUM> may be constructed from a non-thermoplastic material designed to resist melting while heat is applied to reflow outer sheath <NUM> and spine <NUM> together. Additionally, it is contemplated that the arrangement of liner <NUM>, outer sheath <NUM> and spine member <NUM> may include a variety of configurations throughout the manufacturing steps. For example, examples contemplated herein may include different positions, alignment, spacing, sizes, dimensions, etc. of spine <NUM>, liner <NUM> and/or sheath <NUM> relative to one another during the manufacturing process and/or final design.

Additionally, it can be appreciated that outer sheath <NUM> may include a given wall thickness at various locations along its length. It can further be appreciated that the wall thickness of outer sheath <NUM> may vary along its length. For example, while some examples contemplated herein may include apertures <NUM> being defined as "holes" through the wall of outer sheath <NUM>, in other examples, apertures <NUM> may be defined as substantially "thinner" sections of the wall of outer sheath <NUM>.

In some examples, outer sheath <NUM> may be configured to separate, split, or tear as liner <NUM> is expanded from a first configuration to a second, expanded configuration. The expansion may be due to a radially outward force applied from within liner <NUM>. In some examples, outer sheath <NUM> may be configured to separate, split, perforate and/or tear along and/or through the plurality of apertures <NUM>, or other weakening features formed in the wall of outer sheath <NUM>. In other words, outer sheath <NUM> may separate, split, or tear where outer sheath <NUM> is discontinuous and/or constructed of a thinner material. In other words, as liner <NUM> radially expands outward toward an expanded configuration, outer sheath <NUM> may tear along preferential tear points corresponding to apertures <NUM>. Further, the expansion of sheath <NUM> may correlate with the expansion of the lumen <NUM>. Lumen <NUM> may expand from a first inner diameter and/or the first inner radial extent to a second inner diameter and/or a second inner radial extent.

As discussed above, the plurality of apertures <NUM>, or other weakening features formed in the wall of outer sheath <NUM> may be positioned adjacent to, radially outward of, in communication with, and/or directly over the one or more folds <NUM> formed in liner <NUM>. As mentioned above, in some examples, the plurality of apertures <NUM>, or other weakening features formed in the wall of outer sheath <NUM> may be arranged in one or more longitudinal lines along the length of the expandable introducer <NUM>, liner <NUM> and/or outer sheath <NUM>. Accordingly, in some examples, the plurality of apertures <NUM> or other weakening features formed in the wall of outer sheath <NUM> may be arranged in one or more longitudinal lines adjacent to, radially outward of, in communication with, and/or directly over the one or more folds <NUM> and/or the two or more secondary folds formed in liner <NUM>. In some examples, the one or more longitudinal lines may directly correspond to the one or more folds <NUM> and/or the two or more secondary folds. In some examples, there may be more longitudinal lines than folds and/or secondary folds (i.e., <NUM> folds with <NUM> or more lines of openings, cutouts, etc., <NUM> folds with <NUM> or more lines of openings, cutouts, etc.). In some examples, the reduced thickness region and/or a substantially thinner thickness of outer sheath <NUM> may be disposed adjacent to, radially outward of, in communication with, and/or directly over the one or more folds <NUM> and/or the two or more secondary folds of liner <NUM>.

<FIG> is a cross-sectional view (along line <NUM>-<NUM> of <FIG>) of the second expandable section <NUM> of introducer <NUM> in an expanded configuration. For example, <FIG> may depict the expanded configuration of the unexpanded introducer illustrated in <FIG>. In other words, <FIG> may depict introducer <NUM> prior to a medical device being inserted through second expandable section <NUM> of introducer <NUM>, while <FIG> may depict introducer <NUM> after a medical device has been inserted through second expandable section <NUM>.

As shown in <FIG>, liner <NUM> has expanded to a position in which the three folded sections <NUM> (shown in <FIG>) have expanded (e.g., unfolded) to a position in which the outer surface of liner <NUM> contacts the inner surface of first rib member <NUM> and second rib member <NUM> of ribcage <NUM>. Additionally, it can be appreciated that liner <NUM> may continue to expand after it initially contacts the inner surface of ribcage <NUM>, thereby applying a radially outward force on the first rib member <NUM> and second rib member <NUM> of ribcage <NUM>.

However, as illustrated in <FIG> and described above, first rib member <NUM> and second rib member <NUM> of ribcage <NUM> may expand (e.g., flex) radially outward to accommodate the outward expansion of liner <NUM>. <FIG> (in comparison to <FIG>), illustrates the increased distance between the ends of first rib member <NUM> and second rib member <NUM>. Specifically, and in accordance with the invention it is desirable to design liner <NUM>, ribcage <NUM> and sheath <NUM> to be able to move (e.g., slide) relative to one another as second expandable portion <NUM> of introducer <NUM> expands. For example, it may be desirable for first rib member <NUM> and second rib member <NUM> of ribcage <NUM> to slide along the outer surface of liner <NUM>. Additionally, as liner <NUM> and ribcage <NUM> are expanding, it is contemplated that sheath <NUM> may slide along the outer surface of ribcage <NUM> and/or liner <NUM>. Further, in some instances a portion of sheath member <NUM> may stretch to accommodate the expanded configuration (e.g., increased diameters) of both liner <NUM> and/or ribcage <NUM>). It is contemplated that as sheath <NUM> stretches, its wall thickness may decrease.

Additionally, can be appreciated that after a radially outward force is no longer applied to sheath <NUM>, ribcage <NUM> and/or liner <NUM>, introducer <NUM> may contract to a configuration that resembles the unexpanded configuration of introducer <NUM> described above. It can be appreciated that after introducer <NUM> has been expanded, its configuration may be different from its configuration pre-expansion. For example, after having been expanded, a portion of liner <NUM> may extend beyond first rib member <NUM> and second rib member <NUM> of ribcage <NUM>. In other words, a portion of liner <NUM> may be positioned between the outer surface of first rib member <NUM> and/or second rib member <NUM> and the inner surface of sheath <NUM>.

<FIG> is a perspective view of an example spine member <NUM> including reinforcement members <NUM> extending from a distal end <NUM> of spine <NUM> to a proximal end <NUM> of spine <NUM>. <FIG> shows spine member <NUM> member having openings <NUM> defined between adjacent reinforcement members <NUM>. While <FIG> shows spine member <NUM> having three reinforcement members <NUM>, it is contemplated that spine member <NUM> may have less than or greater than three reinforcement members <NUM>. For example, spine member <NUM> may have <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more reinforcement members <NUM>. Further, <FIG> shows that in some examples, the width of reinforcement members <NUM> may be substantially uniform. In other words, the width of reinforcement members <NUM> may remain substantially uniform along spine member <NUM> from proximal end <NUM> to distal end <NUM>. Additionally, <FIG> shows reinforcement members <NUM> spaced substantially equidistant around longitudinal axis <NUM>. However, it is further contemplated that reinforcement members <NUM> may be spaced at variable distances around longitudinal axis <NUM>.

<FIG> illustrates another example spine member <NUM>. The spine member <NUM> of <FIG> may be similar to the spine member <NUM> shown in <FIG>. However, the spine member <NUM> of <FIG> may include one or more reinforcement members <NUM> having a variable width along the length of spine member <NUM>. For example, <FIG> shows an example reinforcement member <NUM> having a width "A" at one location and a different width "B" at a different location. As shown in <FIG>, in some examples width "B" may be substantially less than width "A. " In other examples, width "B" may be substantially greater than width "A. " Further, it is contemplated that the width of one or more of reinforcement members <NUM> may taper in any direction along spine member <NUM>. As illustrated in <FIG>, the width of reinforcement members <NUM> may taper from width "A" to a width "B," whereby width "B" remains substantially constant in at least a portion of the distal region <NUM> of introducer <NUM>. Additionally, it can be appreciated that any example spine member described herein may include a given wall thickness at various locations along its length. It can further be appreciated that the wall thickness of any spine member described herein may vary along its length.

<FIG> and <FIG> show spine members <NUM> and <NUM> including collar portions <NUM>. Collars <NUM> may be utilized during the manufacturing process and may or may not be positioned at the distal <NUM> and/or proximal <NUM> end of spine members <NUM> and <NUM>. In some instances, collars <NUM> may be removed during the manufacturing process.

In some instances, manufacturing introducer <NUM> may result in introducer <NUM> having one or more radially extending bumps (e.g., raised portions, ridges, etc.). The raised portions may extend radially away from the outer surface of introducer <NUM>. For example, the one or more raised portions may extend radially away from the outer surface of outer sheath <NUM>. For example, in some examples a raised portion may substantially align with (e.g., be positioned above) a folded portion <NUM> of liner <NUM>.

In some instances, it may be desirable to remove at least a portion of raised portion prior to performing one or more manufacturing steps (e.g., adding a tip member). <FIG> illustrates an example section of liner <NUM> which may be removed prior to performing one or more manufacturing steps. For example, <FIG> shows a line <NUM> along which a cut, skive, grinding, shaving, etc. may be performed to remove material prior to performing one or more manufacturing steps. It can appreciated that any suitable method may be utilized to remove a portion of liner <NUM>.

In some examples, the material removed from liner <NUM> may include a portion of one or more folded sections <NUM>. For example, <FIG> shows line <NUM> which may represent a cut which removed a portion of folded section <NUM>. Additionally, <FIG> shows reinforcement members <NUM>. Reinforcement members <NUM> may have material removed from a distal end thereof. For example, one or more reinforcement members <NUM> may include a tapered, beveled or chamfered distal end.

Additionally, in some examples the distal end of the liner <NUM>, sheath <NUM> and/or spine <NUM> may have material uniformly removed prior to performing additional manufacturing steps (e.g., adding a tip member). <FIG> shows a side view of the end of liner <NUM>, which may or may not include outer sheath <NUM> and/or reinforcement members <NUM>. For example, reference number <NUM> may define a liner <NUM>, outer sheath <NUM>, spine <NUM> or any combination thereof. Additionally, reference numeral <NUM> may define a spine member or folded section <NUM> of liner <NUM>.

As shown in <FIG>, the distal end <NUM> of example member <NUM> may include a radius, chamfer and/or bevel around the circumference example member <NUM>. This bevel, chamfer and/or radius may represent material which has been removed from the distal end of example member <NUM> prior to performing additional manufacturing steps. Additionally, it is contemplated that in some examples, the liner/spine <NUM>/<NUM> discussed above may have a bevel, chamfer and/or radius applied to its distal end during the manufacturing process.

In some examples it may be desirable to add a tip member to the distal end of any of the examples disclosed herein. <FIG> shows an example tip member <NUM> disposed along the distal region <NUM>. Tip member <NUM> may be designed with a low durometer material. In some instances, a lower durometer material may provide tip member <NUM> with the ability to radially expand (e.g., flex) outward and radially contract as a variety of medical devices are advanced through tip member <NUM>. Further, tip member <NUM> may include a taper. As shown in <FIG> tip member <NUM> may taper from a first diameter in which it contacts outer sheath <NUM> to a second diameter at the distal end of introducer <NUM>. While not intended to be limiting, in some examples the shape of tip member <NUM> may resemble a bull-nose. Additionally, tip member <NUM> may include a radiopaque material. The radiopaque material may allow tip member <NUM> to be visualized by a clinician during a medical procedure. Additionally, <FIG> shows the portion <NUM> of fold <NUM> which had been removed (as discussed with respect to <FIG>) prior to the application of tip member <NUM>. In some instances, portion <NUM> may correspond to a portion of fold <NUM> which had been cut off prior to application of tip member <NUM>. In some examples, tip member <NUM> may include one or more preferential tear regions <NUM>. Tear regions <NUM> may be defined as a slit, score, skive, groove, etc. which may preferentially tear upon radially expansion of tip member <NUM>.

<FIG> illustrates another example ribcage <NUM>. As shown in <FIG>, ribcage <NUM> may include a first set of rib members <NUM> positioned adjacent a second set of rib members <NUM>. Additionally, <FIG> illustrates that both the first set of rib members <NUM> and the second set of rib members <NUM> include a curved portion. Additionally, <FIG> further illustrates that the first set of rib members <NUM> and the second set of rib members <NUM> extend away from a central spine portion <NUM>. Specifically, the first set of rib members <NUM> extend away from the central spine portion <NUM> in a clockwise direction while the second set of rib members <NUM> extend away from the central spine portion <NUM> in a counterclockwise direction. In some instances, first set of rib members <NUM> may be described as extending away from a first lateral edge <NUM> of central spine member <NUM> and the second set of rib members <NUM> may be described as extending away from a second lateral edge <NUM> of central spine member <NUM>. Further, while first set of rib members <NUM> and second set of rib members <NUM> extend away from the first lateral edge <NUM> and second lateral edge <NUM> of spine member <NUM>, they eventually begin to curve back toward each other. However, in contrast to the rib members described in <FIG>, the first set of rib members <NUM> and second set of rib members <NUM> in <FIG> may not interdigitate with one another. Rather, each end of the first set of rib members <NUM> may radially align with each end of the second set of rib members <NUM>. In other words, the ends of the first set of rib members <NUM> may not extend past (e.g., may not interdigitate with) the ends of the second set of rib members <NUM>. Additionally, <FIG> illustrates the curved shape of both first set of rib members <NUM> and second set of rib members <NUM> forms a lumen <NUM>. As discussed herein, liner <NUM> may extend within lumen <NUM>.

<FIG> illustrates another example ribcage <NUM>. As shown in <FIG>, ribcage <NUM> may include a first set of rib members <NUM> positioned adjacent a second set of rib members <NUM>. Additionally, <FIG> illustrates that both the first set of rib members <NUM> and the second set of rib members <NUM> include one or more curved portions. Further, <FIG> shows that first set of rib members <NUM> are longitudinally offset from the second set of rib members <NUM>. Additionally, <FIG> further illustrates that the first set of rib members <NUM> and the second set of rib members <NUM> extend away from a central spine portion <NUM>. <FIG> illustrates the curved shape of both first set of rib members <NUM> and second set of rib members <NUM> forms a lumen <NUM>.

<FIG> illustrates another example introducer <NUM>. Introducer <NUM> may be similar in form and function to introducer <NUM> described above. For example, introducer <NUM> may include an expandable portion <NUM>. The proximal portion of expandable portion <NUM> may be coupled to hub <NUM>.

Additionally, introducer <NUM> may further include an elongated compliant liner (not shown) having a lumen <NUM>. The liner may extend along both expandable portion <NUM>. The introducer <NUM> may also include an outer sheath <NUM>. Sheath <NUM> may extend along (e.g., cover) expandable portion <NUM>. As illustrated in <FIG>, expandable section <NUM> may include a ribcage <NUM>. Ribcage <NUM> may include a first set of rib members <NUM> positioned adjacent a second set of rib members <NUM>. Rib members <NUM> and <NUM> may be similar in form and function to any of the other rib members described above.

In contrast to introducer <NUM> (described above), introducer <NUM> may be free from the elements described with respect to first expandable section <NUM> (see <FIG>). Rather, ribcage <NUM>, the liner and sheath <NUM> may extend the entire length of introducer <NUM>. Additionally, ribcage <NUM>, liner <NUM> and sheath <NUM> may be configured (along the entire length of introducer <NUM>) as shown in <FIG>. However, ribcage <NUM> may shift from a first unexpanded configuration to and expanded configuration as described above with respect to second expandable section <NUM> of introducer <NUM>. For example, introducer <NUM> may shift from an unexpanded configuration illustrated and described with respect to <FIG> to an expanded configuration illustrated and described with respect to <FIG>. <FIG> illustrates the curved shape of both first set of rib members <NUM> and second set of rib members <NUM> forms a lumen <NUM>.

In some examples, the example expandable introducer <NUM> (or other introducers and components thereof described herein) may be disposed about or inserted over a guidewire (not shown), although the guidewire is not required. In some examples, the expandable introducer <NUM> and/or liner <NUM> may include a proximal non-expandable section and a distal expandable section. In examples having a proximal non-expandable section, the proximal non-expandable section may have an inner diameter or extent sufficient to accept a medical device passing therethrough, while the distal expandable section may have an inner diameter or radial extent in a relaxed condition that is less than a maximum outer diameter or extent of the medical device. The expandable introducer <NUM> and/or liner <NUM> may be formed using any of the techniques or structures discussed herein.

An example method of use of introducer <NUM> (or other introducers and components thereof described herein) may include inserting introducer <NUM> into and/or navigated within a vessel or body lumen to a target site or area of interest. In some embodiments, the vessel or body lumen may include a partial or total occlusion or obstruction formed therein. Importantly, the introducer <NUM> may be used in a vessel or body lumen that does not include a partial or total occlusion therein.

After navigating the introducer <NUM> (or other introducers and components thereof described herein) to the target site or area of interest, an elongate dilator may be inserted into the lumen <NUM> of the liner <NUM> and advanced distally toward the distal end <NUM> of introducer <NUM>, liner <NUM>, and/or outer sheath <NUM>. As the dilator reaches, encounters, and/or engages the lumen <NUM> of the liner <NUM>, the dilator may exert a radially outward force from within the lumen <NUM> upon the wall of the liner <NUM> and/or the outer sheath <NUM>. Initially, the radially force may cause the liner <NUM>, ribcage <NUM> and sheath <NUM> to expand as the dilator advances through second expandable section <NUM>. Additionally, the radially outward force may further cause the outer sheath <NUM> to separate, split, or tear along and/or through the plurality of openings, cutouts, perforations, notches, holes, apertures, or other weakening features formed in the wall of the outer sheath <NUM> as the dilator is advanced distally through the lumen <NUM> of the liner <NUM> within first expandable section <NUM>. As the outer sheath <NUM> separates, splits, or tears apart, the one or more folds <NUM> of the liner <NUM> are permitted to unfold and increase the inner diameter of the lumen <NUM>. In a vessel or body lumen having a partial or total occlusion, when the dilator may be advanced through the occlusion and/or the outer sheath <NUM> is opened/expanded within the occlusion, the vessel or body lumen may be deformed or distended by the rigidity of the dilator moving the occlusive material radially outward. Once positioned appropriately adjacent the target site, introducer <NUM> may be utilized as an access pathway for additional medical devices.

In some examples, introducer <NUM> (or other introducers and components thereof described herein) may be made from materials such as metals, metal alloys, polymers, ceramics, metal-polymer composites, or other suitable materials, and the like. Some examples of suitable materials may include metallic materials such as stainless steels (e.g. 304v stainless steel or <NUM> stainless steel), nickel-titanium alloys (e.g., nitinol, such as super elastic or linear elastic nitinol), nickel-chromium alloys, nickel-chromium-iron alloys, cobalt alloys, nickel, titanium, platinum, or alternatively, a polymeric material, such as a high performance polymer, or other suitable materials, and the like. The word nitinol was coined by a group of researchers at the United States Naval Ordinance Laboratory (NOL) who were the first to observe the shape memory behavior of this material. The word nitinol is an acronym including the chemical symbol for nickel (Ni), the chemical symbol for titanium (Ti), and an acronym identifying the Naval Ordinance Laboratory (NOL).

In some examples, the introducer <NUM> (or other introducers and components thereof described herein) may be made from materials such as, for example, a polymeric material, a ceramic, a metal, a metal alloy, a metal-polymer composite, or the like. Examples of suitable polymers may include polyurethane, a polyether-ester such as ARNITEL® available from DSM Engineering Plastics, a polyester such as HYTREL® available from DuPont, a linear low density polyethylene such as REXELL®, a polyamide such as DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem, an elastomeric polyamide, a block polyamide/ether, a polyether block amide such as PEBA available under the trade name PEBAX®, silicones, polyethylene, Marlex high-density polyethylene, polyetheretherketone (PEEK), polyimide (PI), and polyetherimide (PEI), a liquid crystal polymer (LCP) alone or blended with other materials. In some examples, a suitable polymeric material may have a yield strain of at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, or more. In some examples, the sheath, the membrane, and/or the plurality of corrugations may be made from a material having a low coefficient of friction. In some examples, the sheath, the membrane, and/or the plurality of corrugations may be formed from a fluoropolymer, such as polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP).

Portions of introducer <NUM> (or other introducers and components thereof described herein) may be made of, may be doped with, may include a layer of, or otherwise may 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 such as X-ray during a medical procedure. This relatively bright image aids the user of device in determining its location. For example, one or more of the elements described above (i.e., the sheath, the membrane, the medical device, etc.) may include or be formed from a radiopaque material. Suitable materials can include, but are not limited to, bismuth subcarbonate, iodine, gold, platinum, palladium, tantalum, tungsten or tungsten alloy, and the like.

It should be understood that although the above discussion was focused on percutaneous medical procedures within the vasculature of a patient, other examples in accordance with the disclosure can be adapted and configured for use in other parts of the anatomy of a patient. For example, devices in accordance with the disclosure can be adapted for use in the digestive or gastrointestinal tract, such as in the mouth, throat, small and large intestine, colon, rectum, and the like. For another example, devices can be adapted and configured for use within the respiratory tract, such as in the mouth, nose, throat, bronchial passages, nasal passages, lungs, and the like. Similarly, the devices described herein with respect to percutaneous deployment may be used in other types of surgical procedures as appropriate. For example, in some examples, the devices may be deployed in a non-percutaneous procedure. Devices in accordance with the disclosure can also be adapted and configured for other uses within the anatomy.

Claim 1:
An introducer (<NUM>), comprising:
an inner liner (<NUM>) including a lumen (<NUM>), a proximal region (<NUM>), and at least one folded portion (<NUM>) extending longitudinally along the proximal region;
an expandable support member (<NUM>), the support member includes a spine (<NUM>) extending along the length of the support member (<NUM>) and a plurality of ribs (<NUM>, <NUM>) extending along a length of the support member (<NUM>), the plurality of ribs including a first set of rib members (<NUM>) and a second set of rib members (<NUM>); and
a sheath (<NUM>) attached to at least a portion of the support member (<NUM>);
characterized in that
the support member (<NUM>) is designed to shift from a first position in which the first set of rib members (<NUM>) interdigitate with the second set of rib members (<NUM>) to an expanded position in which the first set of rib members (<NUM>) and the second set of rib members (<NUM>) radially separate from one another, in that the spine is attached to the sheath, and in that the plurality of ribs (<NUM>, <NUM>) are free to move relative to the liner (<NUM>), the sheath (<NUM>), or both the liner (<NUM>) and the sheath (<NUM>).