WO2007005584A1

WO2007005584A1 - Introducer and exchange sheath

Info

Publication number: WO2007005584A1
Application number: PCT/US2006/025537
Authority: WO
Inventors: Laveille Kao Voss; Douglas Rowe; Scott Mcintosh; Dawn Ma
Original assignee: Abbott Laboratories
Priority date: 2005-06-30
Filing date: 2006-06-29
Publication date: 2007-01-11
Also published as: EP1931412A1

Abstract

In accordance with the present invention there is provided exemplary embodiments of an introducer sheath in accordance with the present invention, wherein the introducer sheath of the present invention is formed of multiple components which are resiliently assembled to form a single introducer sheath. One embodiment of the introducer sheath includes a hub, a retaining member and an elongated tubular member. The hub has a lumen that has a groove. The elongated tubular member has a proximal end that includes a flared portion. The distal end of the retaining member is configured to be received in the groove formed in the lumen of the hub. The distal end of the retaining member contacts the flared portion of the tubular member when distal end of the retaining member is disposed in the groove such that the tubular member is retained within the lumen of the hub in a sealed engagement.

Description

INTRODUCERAND EXCHANGE SHEATHS BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates generally to medical devices and methods. More specifically, the present invention relates generally to introducer sheaths and, in particular, various embodiments of introducer sheaths and their methods of use and manufacture. The introducer sheath in accordance with the present invention is generally for use during minimally invasive medical procedures.

2. The Relevant Technology A wide variety of introducer sheaths have been developed for medical use. Introducer sheaths are often used to access a vessel or artery to allow a surgical procedure to be performed. For example, introducer sheaths are often used for medical procedures that utilize catheters, such as angioplasty or stenting procedures. In practice, the introducer sheath is typically inserted into the patient's vasculature using the modified Seldinger technique. Under the Seldinger technique, a needle is first inserted into the vessel. A guidewire is then inserted through the needle and into the vessel. Next, the needle is removed and a sheath/ dilator combination is advanced over the guidewire. The dilator is used to expand the puncture in the vessel to a size suitable to receive an introducer sheath. After the distal end of the sheath is disposed within the vessel, the dilator and guidewire are removed, thereby allowing access to the vessel.

Conventionally, introducer sheaths are formed of three or more components that require assembly: an elongated tubular member, a hub portion, and a hemostasis valve disposed within the hub portion. In some designs an introducer sheath may also include a strain relief member which is disposed adjacent the distal end of the hub and about the proximal end of the elongated tubular portion. A suitable example of such an assembly is shown in United States Patent No. 5,807,350, which discloses an introducer sheath having a construction similar to that described above, the entirety of which is hereby incorporated herein by reference. Introducer sheaths, such as that described above, are generally constructed of multiple pieces which must be assembled to form the sheath. In most cases, the distal end of the hub portion is molded over the elongated tubular member. While molding may produce a stronger part, there is the possibility of damaging a portion of the other components of the device during the process. Any such damage results in the entire device having to be thrown away. As a result, there is a need for a way to attach the proximal end of the tubular member to the distal end of the hub portion which still meets all of the requirements of the introducer sheath, including but not limited to forming a fluid seal and having sufficient strength between the attachment of the hub portion and the tubular member to remain attached, but does not require throwing the entire device away if a portion of the sheath is damaged during manufacturing or assembly. Prior introducer sheaths with such a substantially overmolded design had difficulty accounting for or accommodating the variations that occur in the manufacturing process. When a defect occurred, even if it is only in a portion of the sheath, the unit must be discarded resulting in higher manufacturing costs and lower yields. Similarly, the overmolded design of introducer sheaths made it difficult to change materials during the manufacturing process or even changing the design of the sheath itself. Where an overmolded process is used to create the overmolded introducer sheath, all the portions of the sheath are subjected to the heat from the molding process. As a result, the manufacturing processing itself may result in an uncontrolled change in geometry or a general decrease in quality control. Thus, there is a need for a new introducer sheath having lower manufacturing costs and higher quality control while still retaining the important requirements for an introducer sheath.

The sheaths disclosed herein can be used with various medical devices. In one configuration, the sheath can be used in combination with a vessel closure device, such as those shown in US Patent No. 6,197,042 and pending US Patent Application Number 1210/638,115 filed August 8, 2003 entitled "Clip Applier and Methods," each of these assigned to a common owner and herein incorporated in their entireties by reference.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. BRIEF SUMMARY OF THE INVENTION

These and other limitations are overcome by embodiments of the invention, which relates to medical devices and methods of use of, in particular, introducer sheaths. Embodiments of the invention provide several designs and methods of manufacture of the improved introducer sheath. One embodiment of the invention includes an introducer sheath formed as multiple components which can then be separately assembled to form an introducer sheath. In this embodiment, the components are assembled using resilient connections. One embodiment of the introducer sheath includes a hub, a retaining member, and an elongated tubular member. The hub has a proximal end and a distal end with a lumen extending therebetween. In one embodiment, a portion of the lumen of the hub has a groove formed therein. The elongated tubular member has a distal end and a proximal end of which a portion is flared. The retaining member of the introducer sheath has a proximal end and a distal end configured to be received in the groove formed in the lumen of the hub. The distal end of the retaining member contacts the flared portion of the tubular member when the distal end of the retaining member is disposed in the groove such that the tubular member is retained within the lumen of the hub. In one embodiment described above, a geometric pattern may be formed on the inner surface of the elongated tubular portion of the sheath, wherein the geometric pattern aids in splitting of the introducer sheath if desired.

In another embodiment, the introducer sheath may be manufactured to be splitable during use. That is, the elongated tubular member may have a pre-scored line or another feature that allows it to split along a pre-determined path. In these instances, the choice of the material for the tubular shaft must be balanced between being splitable and being kink resistant and providing good performance. Therefore, there is a need for an improved introducer sheath having good kink resistance and good splitting properties.

In accordance with an alternative embodiment of the unitary sheath described above, a geometric pattern may be formed on the inner surface of an elongated flexible tubular portion of the sheath. The geometric pattern aids in splitting of the sheath if desired. In another alternative embodiment of the sheath, the sheath can further include a strain relief portion formed adjacent the distal end of the hub and adjacent the proximal end of the sheath. hi yet another embodiment of the sheath in accordance with the present invention there is provided a unitary sheath member that can be constructed utilizing an injection molding or co-extrusion process using at least two different materials. A first material can be utilized to form the hub and a portion of the elongate tubular portion extending therefrom and a second material fills in the remaining portion of the tubular portion. By utilizing two different materials to form the sheath, certain characteristics can be achieved, for example good kink resistance and easy splitability. hi another embodiment, the introducer sheath may be manufactured to be splitable during use. That is, the elongated tubular portion may have a pre-scored line, which can be one embodiment of a geometric pattern, or another feature that allows it to split along a pre-determined path. For instance, the elongated tubular portion can include a weakened portion that has a lower strength than other portions of the elongated tubular portion. In these instances, the choice of the tubular shaft material can be balanced between being splitable and being kink resistant and providing good performance, hi accordance with an alternative embodiment of a unitary sheath in accordance with the present invention there is provided a unitary sheath having a geometric pattern formed on the inner surface of an elongated flexible tubular portion of the sheath. The geometric pattern aids in splitting of the sheath if desired. In another alternative embodiment of the sheath, the sheath can further include a strain relief portion formed adjacent the distal end of the hub and adjacent the proximal end of the sheath. In yet another embodiment of the unitary sheath in accordance with the present invention there is provided a unitary sheath member that can be constructed utilizing an injection molding or co-extrusion process using at least two different materials. A first material can be utilized to form the hub and a portion of the elongate tubular portion extending therefrom and a second material fills in the remaining portion of the tubular portion. By utilizing two different materials to form the sheath, certain characteristics can be achieved, for example good kink resistance and easy splitability. hi another embodiment, the unitary sheath may be manufactured to be splitable during use. That is, the elongated tubular portion may have a pre-scored line, which can be one embodiment of a geometric pattern, or another feature that allows it to split along a pre-determined path. For instance, the elongated tubular portion can include a weakened portion that has a lower strength than other portions of the elongated tubular portion. In these instances, the choice of the tubular shaft material can be balanced between being splitable and being kink resistant and providing good performance. hi accordance with yet another alternative embodiment of the present invention, there is provided an alternative embodiment of an expandable sheath in accordance with the present invention. Embodiments of the invention provide several designs and methods of manufacture of an expandable introducer sheath. One embodiment is an introducer sheath formed as a unitary device using, for example, and injection molding process or a co-extrusion process.

In one configuration of an expandable introducer sheath, one or more materials are used to form the sheath. At least one of the materials provides elasticity. The elasticity enables the sheath to expand, thereby accommodating the introduction and/or removal of medical devices that could not previously be accommodated. hi one configuration, the introducer sheath includes a hub portion and a tubular portion. A valve member (such as a hemostasis valve) can be disposed into the hub portion either during the molding process or after the initial molding process. The hemostasis valve can be retained either by an additional element such as a cap or through an element formed during the molding process or during a subsequent molding process.

The tubular portion can include a sheath portion and an elastic portion, which can be formed as a unitary portion through injection molding or co-extrusion processes, for example. The elastic portion of the sheath may be an elastomer that is integrated with another material in the sheath portion that provides rigidity and/or prevents a lumen of the tubular portion from collapsing. When a medical device is withdrawn, for example, the elastic portion can expand thereby permitting the medical device to be withdrawn without splitting the introducer sheath. Advantageously, this enables the use of a subsequent medical device, such as a vessel closure device, to be introduced through the intact sheath, whether or not the vessel closure device splits or cuts the introducer sheath during use. Additional features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention as set forth hereinafter. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above-recited and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: Figure 1 is an exploded perspective view of an exemplary embodiment of an introducer sheath;

Figure 2 is a partial cross-sectional view of one embodiment of an assembled introducer sheath in accordance with the present invention;

Figure 3 is a cross-sectional view of one embodiment of a hub of the introducer sheath of Figure 2 in accordance with the present invention; Figure 4 is a partially exploded, cross-sectional view of the introducer sheath of Figure 2 illustrating the individual components partially assembled to form the introducer sheath in accordance with the present invention;

Figure 5 a partial cross-sectional view of one embodiment of the elongated tubular member of the introducer sheath of Figure 2 in accordance with the present invention; Figure 6 is a partially exploded, cross-sectional view of the introducer sheath of Figure 2 illustrating the components further partially assembled to form a sheath in accordance with the present invention;

Figure 7 is a partial elevation view of one exemplary embodiment of a dilator used with the introducer sheath of Figure 2 in accordance with the present invention; Figure 8 is a partial cross-sectional, elevation view of the dilator of Figure 7 attached to the introducer sheath of Figure 2 in accordance with the present invention; Figure 9 is a partial cross-sectional view of an alternate embodiment of the flared portion of proximal end of an elongated tubular member of an introducer sheath in accordance with the present invention;

Figure 10 is a partial cross-sectional view of an alternate embodiment of a portion of an overmolded introducer sheath in accordance with the present invention illustrating an overmolded hub, proximal end of the tubular member and a locking ring;

Figure 11a is a perspective view of one embodiment of a locking ring used in the introducer sheath of Figure 10;

Figure 1 Ib is a perspective view of an alternate embodiment of a locking ring used in the introducer sheath of Figure 10;

Figure 12A is a plan view of an exemplary embodiment of an introducer sheath in accordance with the present invention;

Figure 12B illustrates a cross sectional view of the sheath in Figure 12A and illustrates a valve disposed in the sheath's hub and an alignment member; Figure 12C is a cross-sectional view taken along line 12C -12C of the sheath of Figure

12A in accordance with the present invention;

Figure 13A illustrates a cross sectional view of another sheath in accordance with the present invention;

Figure 13B is cross-sectional view of an alternative embodiment of the sheath of Figure 13A illustrating the geometric features formed within wall of the sheath in accordance with the present invention;

Figure 13C is a cross-section view of a portion of an another alternative embodiment of the sheath of Figure 13B in accordance with the present invention;

Figure 14A is a plan view of an alternative embodiment of a sheath in accordance with the present invention;

Figure 14B is a cross-sectional view of the sheath of Figure 14A taken along line MAMA in accordance with the present invention;

Figure 14C illustrates a cross sectional view of an alternative embodiment of a sheath in accordance with the present invention; Figure 15 is a plan view of an exemplary embodiment of an introducer sheath in accordance with the present invention; Figure 16 illustrates a cross sectional view of one embodiment of the introducer sheath in Figure 15;

Figure 17 illustrates a cross sectional view of another embodiment of the introducer sheath in Figure 15; Figure 18 illustrates a cross sectional view of yet another embodiment of the introducer sheath in Figure 15;

Figure 19 illustrates a cross sectional view of another embodiment of the introducer sheath in Figure 15 ;

Figure 2OA illustrates an introducer sheath prior to insertion of a medical device; Figure 2OB illustrates an introducer sheath prior to removal of a medical device that has changed size during use;

Figure 2OC illustrates an embodiment of the introducer sheath during removal of the medical device that has changed size during use; and

Figure 2OD illustrates the use of a vessel closure device that is introduced through the sheath after the medical device illustrated in Figures 2OA and 2OB has been withdrawn. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

In accordance with the present invention, an introducer sheath formed as multiple components which can then be separately assembled to form an introducer sheath. In one embodiment, the components are assembled using a resilient engagement. In one embodiment, the introducer sheath comprises a hub having a proximal end and a distal end. The proximal end of the hub is configured to receive a flexible membrane or valve therein. The introducer sheath further includes an elongated tubular member generally extending from the distal portion of the hub. The elongated tubular member is generally centered with an axis of the hub.

Figure 1 depicts an exploded view of the individual components of one embodiment of an introducer sheath 10. Figure 2 illustrates a cross-sectional view of an exemplary embodiment of an assembled introducer sheath 10 in accordance with the present invention. As shown in Figures 1 and 2, the introducer sheath 10 includes a hub 20, a cap 30, a retainer 40, and a generally elongate tubular member 50 extending outwardly from one end of the hub 20. The introducer sheath 10 also includes a flexible membrane or hemostasis valve 60. As illustrated in Figures 1 and 2, introducer sheath 10 includes an optional strain relief member 80.

As shown in further detail in Figure 3, the hub 20 includes a main body 21 having a proximal end 22 and a distal end 23 and a central lumen 24 extending therebetween. In one possible embodiment, a port 25 may be provided in the side of the main body 21 of hub 20. The port 25 formed in the main body 21 of the hub 20 is in fluid communication with the central lumen 24 extending between the proximal end 22 and the distal end 23 of the main body 21 of hub 20.

In an exemplary embodiment depicted in Figure 3, the central lumen 24 comprises a first lumen portion 24a and a second lumen portion 24b. The first lumen portion 24a and the second lumen portion 24b can have a common central axis. It will be appreciated by one skilled in the art that first lumen portion 24a and second lumen portion 24b are not required to have a common central axis. The first lumen portion 24a is proximate to the distal end 23 of the hub 20 while the second lumen portion 24b is proximate to the proximal end 22 of the hub 20. As illustrated in Figure 2 , the first lumen portion 24a is sized and configured so as to receive the proximal end 52 of the tubular member 50 therein. Similarly, the second lumen portion 24b is sized and configured to receive the retainer 40, the flexible member 60, and the cap 30 therein. Returning to Figure 3, in one embodiment the first lumen portion 24a and the second lumen portion 24a are of differing size, hi this embodiment, the first lumen portion 24a is smaller than the second lumen portion 24b. As a result, the interior surface of the hub 20, which is defined by the diameters of the first lumen portion 24a and second lumen portion 24b has a shoulder area 27 in which the first lumen portion 24a transitions to the second lumen portion 24b. The shoulder area 27 may have various configurations as long as it is configured to cooperate with the proximal end 52 of the tubular member 50 and the distal end of the retainer 40 (see Figure 2), as will be discussed in more detail below. In an exemplary embodiment illustrated in Figure 3, the shoulder area 27 includes a ridge 28 and a groove 29. The ridge 28 and the interior surface of the main body 21 of the hub 20 define the groove 29. The groove 29 may have various shapes and configurations as long as it is configured to receive the distal end of retainer 40 and cooperate with the proximal end 52 of the tubular member 50 as depicted in Figure 2 and will be discussed in more detail below. In one embodiment depicted in Figure 3, the groove 29 is a generally U-shaped channel. Alternatively, by way of example and not limitation, the groove 29 could be V-shaped, rounded, squared, tapered, or any combination thereof as long as it is configured to cooperate with retainer 40. As illustrated most clearly in Figure 3, in one exemplary embodiment ridge 28 is generally rectangular in shape. It will be appreciated that ridge 28 could have various shapes and configurations and perform the function thereof. By way of example and not limitation, ridge 28 could be square, round, or oval shaped or have an angular surface, or any combination thereof, as long as it is configured to cooperate with the proximal end of tubular member 50. In another embodiment, a portion of ridge 28 closest to the central axis of the hub 20 has been removed thereby forming an angled surface, hi this embodiment, the angled surface of the ridge cooperates with the proximal end 52 of elongated tubular member 50. As illustrated in Figure 3, the second lumen portion 24b of the central lumen 24 formed in the hub 20 includes features formed therein. As will be described in detail below the features formed in the second lumen portion 24b are configured to receive various corresponding components of the introducer sheath 10.

Returning now to Figure 2, as previously mentioned, the second lumen portion 24b of the central lumen 24 of the hub 20 is configured to receive the retainer 40 therein. The retainer 40 is configured to be detachably received within the central lumen 24 of the hub 20. More specifically, as illustrated in Figure 2, the retainer 40 resiliently cooperates with the interior surface of the main body 21 of the hub 20. It will be appreciated that the outer surface of the retainer 40 could have various configurations as long as the retainer 40 is sized and configured to be received with second lumen portion 24b of central lumen 24. In one possible embodiment, the retainer 40 is also sized and configured so as to be resiliently retained within the second lumen portion 24b of the central lumen 24 of the hub 20.

Figure 4 illustrates a cross-sectional view of one embodiment of the retainer 40 in accordance with the present invention. In one embodiment depicted in Figure 4, the proximal end 42 of the retainer 40 is tapered outwardly so as to resiliently or frictionally engage the interior surfaces of the hub 20. In an exemplary embodiment, the retainer 40 includes locking features 41 formed in the outside surface of the retainer 40. The locking features 41 are configured to be received in corresponding locking features 26 formed in the interior surface of the main body 21 of the hub 20 as depicted in Figure 2 and 4.

In one embodiment illustrated, the locking features 41 and 26 are depicted as being generally rounded in shape. It will be appreciated that the locking features 41 and 26 could have various other configurations so long as they cooperate together in a resilient or frictional engagement and the locking features 41 are received into the corresponding locking features 26. By way of example and not limitation, the locking features 41 and 26 could be ovular, square, rectangular, angular, or various other shapes or combinations thereof. Further, the locking features 41 and 26 could be resilient members that slightly deflect until they snap into place. It will be appreciated by one skilled in the art that while in one embodiment retainer 40 is resiliently engaged in lumen 24 of the hub 20 by a snap-fit or frictional engagement, various other methods of attachment could be utilized, such as welding, adhesives, mechanical fasteners and the like.

One skilled in the art will also appreciate that while in the embodiment illustrated the locking features 41 of the retainer 40 protrude and are received in corresponding locking features 26 in the hub 20, they could be reversed such that the locking features 26 of the hub 20 are received into the locking feature 41 of the retainer. The importance is that the locking features 41 and 26 cooperate so as to resiliently engage and hold the retainer 40 in place in the hub 20. As shown in Figure 4, the retainer 40 includes a proximal end 42 and a distal end 43 with a lumen 44 extending therebetween. The proximal end 42 of the retainer 40 is configured to receive the flexible membrane or hemostasis valve 60 therein as shown in Figure 2. As illustrated in Figures 2, 4, and 6, the distal end 43 of the retainer 40 is configured to be received within the shoulder area 27 of the hub 20. hi particular, the distal end 43 of the retainer 40 is configured to be disposed in the groove 29 of the shoulder area 27. As illustrated in Figures 2 and 4, the distal end 43 of the retainer 40 is configured to cooperate with the proximal end 52 of the tubular member 50 and the groove 29 in the shoulder area 27 of the hub 20 so as to retain the proximal end 52 of the elongated tubular member 50, as will be described in greater detail below, hi one embodiment, the interior surface of the distal end 43 of the retainer 40 has optional angular ridges or teeth-like features (not shown) formed there in that are configured to contact and engage proximal end of the tubular member 50.

Turning back to Figure 4, the flexible membrane 60 includes an opening or a plurality of slits formed therein to form an opening 61. The opening 61 allows a medical device to pass through the flexible membrane 60. It will be appreciated by one skilled in the art that the opening 61 of the flexible membrane 60 may have various other configurations and perform the functions thereof. The flexible membrane 60 and the opening 61 are sized and configured to form a fluid tight seal about the medical device. Flexible membranes of this type are commonly referred to as hemostasis valves. The flexible membrane 60 is configured to cooperate with the proximal end 42 of the retainer 40. More specifically, in one exemplary embodiment, the proximal end 42 of the retainer 40 has a recess 45 formed therein configured to receive the distal end 62 of the flexible membrane 60. It will be appreciated that the recess 45 could have various other configurations as long as it is configured to cooperate with the distal end 62 of the flexible membrane 60. hi one embodiment depicted in Figure 4, the recess 45 is a generally square shaped. Alternatively, by way of example and not limitation, the recess 45 could be rounded, oval, rectangular tapered, or any combination thereof as long as it is configured to cooperate with the distal end 62 of the flexible membrane 60. As illustrated in Figure 4, in one embodiment, correspondingly distal end 62 of the flexible membrane 60 has an opening 64 formed therein configured to cooperate with the proximal end 42 of the retainer 40. It will be appreciated by one skilled in the art that the distal end 62 of the flexible membrane 60, including opening 64, and the proximal end 42 of the retainer 40, including recess 45, could have various other configurations and shapes as long as they are configured to cooperate and have a sealing engagement. Alternatively, by way of example and not limitation, the opening 64 of the flexible membrane 60 and proximal end 42 of the retainer 40 could be U-shaped, round, square, oval, elliptical, tapered, or any combination thereof as long as they are configured to cooperate.

As shown in Figure 2, the flexible membrane 60 is retained between the retainer 40 and the cap 30. An exemplary embodiment of the cap 30 of the present invention is illustrated in Figure 4. In one embodiment, the cap 30 is configured to cooperate with the proximal end 63 of the flexible membrane 60. In particular, in this embodiment the exterior surface of the cap 30 has the recess 31 formed therein which is configured to receive the proximal end 63 of the flexible membrane 60. Similarly, the proximal end 63 of the flexible member 60 has an opening 65 formed therein configured to receive portion 36 of the cap 30. It will be appreciated by one skilled in the art that the distal portion 36 of the cap 30 and the opening 65 in the proximal end 63 of the flexible membrane 60 can have various other configurations and shapes as long as they are configured to cooperate and have a sealing engagement. Alternatively, by way of example and not limitation, that the distal portion 36 of the cap 30 and the opening 65 in the proximal end 63 of the flexible membrane 60 could be U-shaped, round, rectangular square, oval, elliptical, tapered, or any combination thereof as long as they are configured to cooperate.

It will be appreciated that the recess 31 could have various other configurations as long as the proximal end 63 of the flexible membrane 60 and the recess 31 are correspondingly shaped to cooperate, m one embodiment depicted in Figure 4, the recess 31 is a generally square shaped. Alternatively, by way of example and not limitation, the recess 31 could be rounded, oval, rectangular tapered, or any combination thereof as long as it is configured to cooperate with the distal end 62 of the flexible membrane 60.

In one exemplary embodiment, the cap 30 when disposed over the flexible membrane 60 provides a compressive force to the flexible membrane 60, wherein the compressive force exerted on the flexible membrane 60 causes the opening 61 to be squeezed and thereby forming a more fluid tight seal therein. This compressive force however does not reduce access to or increase forces to pass a medical device through the opening 61 of the flexible membrane 60. Additionally, as described above, the compressive force exerted on the flexible membrane 60 increases the sealing of the opening 61 in a static state, the compressive force also increases the seal between the flexible membrane 61 and a medical device disposed through the opening 61 for the same reasons.

As shown in Figures 2 and 4, the exterior surface 32 of the cap 30 is sized and configured to be received within the proximal end 22 of the hub 20. In one embodiment illustrated in Figure 4 , the exterior surface 32 of the cap 30 is slightly angled to form a protrusion so as to be received within a corresponding cutout 15 formed on the interior surface of the proximal end 22 of the main body 21 of the hub 20. As shown in Figure 4 the proximal end 22 of the main body 21 of the hub 20 is configured so as to resiliently move to allow the exterior surface 32 of the cap 30 to be received within the cutout 15 formed therein. In another embodiment, the exterior surface 32 of the cap 30 includes a resilient protrusion which upon the cap 30 being inserted into proximal end of the retainer 40 locks the cap 30 in place. The proximal end 22 of the main body 21 of the hub 20 includes a corresponding cutout 15 configured to receive the resilient protrusion. In either embodiment, the exterior surface 32 of the cap 30 and the interior surface of proximal end of the hub 20 are configured to cooperate such that the cap resiliently snaps into place. It will be appreciated that the exterior surface 32 of the cap 30 can have various other configurations and shapes as long as it is configured to cooperate with the proximal end 22 of the hub 20. In one exemplary embodiment, proximal end 22 of the hub 20 and the exterior surface 32 cooperate form a seal. It will be appreciated by one skilled in the art that while in one embodiment, retainer 40 is resiliently engaged in lumen 24 of the hub 20 by a snap-fit or frictional engagement, various other methods of attachment could be utilized, such as welding, adhesives, mechanical fasteners and the like.

Figure 5 depicts an exemplary embodiment of the tubular member 50 in accordance with the present invention. The tubular member 50 includes a proximal end 52 and a distal end 57 with a lumen 59 extending between the two ends. In one embodiment illustrated in Figure 5, the proximal end 52 of the tubular member 50 includes a flared portion 53 that has generally conical or flared configuration. The tubular member 50, including the flared portion 53, is comprised of a resilient flexible material. As previously mentioned the proximal end 52 of the tubular member 50 is configured to be received proximate to the distal end 23 of the hub 20 as illustrated in Figure 4. In particular, referring now to Figures 4 and 6, the flared portion 53 of the proximal end 52 of the tubular member 50 is configured to cooperate with the shoulder area 27 formed in the main body 21 of the hub 20 and the distal end 43 of the retainer 40. When the tubular member 50 is disposed in the central lumen 24 of the hub 20 and the retainer 40 is then inserted into the central lumen 24 of the hub 20, as illustrated in Figure 6, the distal end 43 of the retainer 40 together with the ridge 28 and the groove 29 of the shoulder area 27 cooperate to retain the flared portion 53 of the distal end 52 of the tubular member 50.

It will be appreciated that the ridge 28 and the groove 29 of the shoulder area 27 of the hub 20, the distal end 43 of the retainer 40, and the flared portion 53 of the proximal end 52 of the tubular member 50 are one possible embodiment of a means for retaining tubular member 50 in the hub 20 in sealing engagement. The retaining means may also consist of the optional angular ridges or teeth-like features formed in the distal end 43 of the retainer configured to contact and engage the proximal end 52 of the tubular member 50. It will be appreciated by one skilled in the art that the retaining means may have various other configurations and perform the function thereof.

Specifically, as the retainer 40 is inserted into the hub 20, the distal end 43 of the retainer 40 contacts the flexible flared portion 53 of the proximal end 52 of the tubular member 50. In one embodiment in which the distal end 43 of the retainer 40, the teeth- like features resiliently contact the flared portion 53 of the proximal end 52 of the tubular member 50. As shown in Figure 6, as the distal end 43 of the retainer 40 moves toward the distal end 23 of the hub 20, the flared portion 53 flexibly moves around the ridge 28 of the shoulder area 27 and the distal end 43 of the retainer 40 until both the distal end 43 of the retainer 40 and the proximal end 52 of the tubular member 50 are disposed in the groove 29. The cooperation between the distal end 43 of the retainer 40, the shoulder area 27 of the hub 20 and the proximal end 52 of the tubular member 50 forms a fluid tight seal. It will be appreciated by one skilled in the art that while in one embodiment, retainer 40 is resiliently engaged in lumen 24 of the hub 20 by a snap-fit or Junctional engagement, various other methods of attachment could be utilized, such as welding, adhesives, mechanical fasteners and the like.

It will be appreciated that the proximal end 52 of the tubular member 50 may have various other configurations. The flared portion 53 may be generally conically shaped as depicted in Figure 5. For example, the flared portion 53 at the proximal end 52 of the tubular member 50 may have various other shapes and configurations. In another embodiment, the flared portion 53 may be more cup-shaped. In addition in other alternative embodiments, flared portion 53, by way of example and not limitation, could be rounded or oval shaped, tapered, or any combination of the above-identified shapes. It will be appreciate that various other angles of the flare for flared portion 53 can be used as long as flared portion 53 is configured to cooperate with ridge 28 of shoulder area 27 and distal end 43 of retainer 40. An alternate embodiment of the proximal end 52 of the tubular member 50 is illustrated in Figure 9. In this embodiment, the proximal end 52 of the tubular member 50 is preformed to cooperate with the ridge 28 and groove 29 of the shoulder area 27 and the distal end 43 of the retainer 40. It will be appreciated that the ridge 28 and the groove 29 of the shoulder area 27 of the hub 20, the distal end 43 of the retainer 40, and the flared portion 53 of the distal end 52 of the tubular member 50 are another possible embodiment of a means for retaining tubular member 50 in the hub 20 in sealing engagement. It will be appreciated by one skilled in the art that the retaining means may have various other configurations and perform the function thereof. It will be appreciated that, although it is not illustrated, the distal end 57 of the tubular member 50 can include a tapered portion depicted in Figure 6 in which the diameter of the tubular member 50 is gradually reduced. Such a tapered portion may be produced through known manufacturing methods such as drawings, sanding, grinding, heat forming or other similar processes.

Figures 4 and 6 are partially exploded cross-sectional views of the introducer sheath 10 in accordance with the present invention during different phases of the assembly process. To assemble the individual components described above into a completed introducer sheath 10, the distal end (not shown) of the tubular member 50 is passed through the central lumen 24 of the hub 20 as depicted in Figure 4. The flared portion 53 of the proximal end 52 of the tubular member 50 is received proximate to the shoulder area 27 of the main body 21 of the hub 20. More specifically, in one embodiment depicted in Figure 4, the flared portion 53 of the proximal end 52 of the tubular member 50 cooperates with the ridge 28 of the shoulder area 27 in the hub 20. Next, as previously mentioned and now illustrated in Figure 6, the retainer 40 is disposed into the central lumen 24 of the main body 21 of the hub 20. As a result, the distal end 43 of the retainer 40 contacts the flared portion 53 of the proximal end 52 of the tubular member 50. In one embodiment of the present invention, the optional angular teeth-like features formed in the interior surface of distal end 43 of retainer 40 contact and resiliently engage the flared portion 53 of the proximal end 52 of the tubular member 50. As illustrated in Figure 6, the flared portion 53 of the tubular member 50 and the ridge 28 are configured to cooperate such that the tubular member 50 is retained in the distal end of the hub 20. As the retainer 40 continues to be moved distally, the locking features 41 of the retainer 40 are received by corresponding locking features 26 formed within the second lumen portion 24b of central lumen 24 of the hub 20, thereby locking the retainer 40 and the tubular member 50 to the hub 20. As the distal end 43 of the retainer 40 moves toward the distal end 23 of the hub 30 until the locking features 41 and 26 engage, the flared portion 53 of tubular member 50 flexibly moves around the ridge 28 of the shoulder area 27 formed in the interior body 21 of the hub 20. When the locking features 41 and 26 engage, the distal end 43 of the retainer 40 has moved the flared portion 53 of the proximal end 52 around the ridge 28 and into the groove 29 such that both the distal end 43 of the retainer 40 and the proximal end 52 of the tubular member 50 are disposed in the groove 29 as illustrated in Figure 6.

The flexible membrane 60 is now inserted into the proximal end 22 of the main body 21 of the hub 20. In particular, the distal end 62 of the flexible membrane 60 is disposed in the recess 45 formed in the proximal end 42 of the retainer 40. Next, the cap 30 is likewise inserted into the proximal end 22 of the main body 21 of the hub 20. The proximal end 63 of the flexible member 60 is disposed into the recess 31 formed in the outer surface 32 of the cap 30. As illustrated in Figure 2, the retainer 40, the cap 30, and the main body 21 of the hub 20 cooperate to hold the flexible member 60 in place. In one embodiment, the flared portion 53 of the tubular member 50 can be utilized to align the lumen of the tubular member 50 with central lumen 24 of the main body 21 of hub 20 such that a single axis bisects the flexible membrane 60, the hub 20, the retainer 40, the cap 30, and the tubular member 50.

As shown in Figures 2, 4 and 6, the main body 21 of the hub 20 can also include an aperture 25, wherein the aperture 25 is configured to be in fluid communication with the lumen 44 of the retainer 40 and the lumen 59 of the elongated tubular member 50. Although not shown, a flexible piece of tubing with a luer fitting or a valve assembly can be attached to the aperture 25 so that fluid can pass through the valve/luer and flexible tubing into the lumen 44 of the retainer 40 and the lumen 59 of the tubular member 50. Alternatively, a finger grip (not shown) may be substituted in place of the valve/luer fitting and tubing in the event that the introducer is to be utilized with a vessel closure system such as that shown in United States Patent Application Serial No. 10/356,214 filed August 5, 2004 entitled "Clip Applier and Methods of Use" the entirety of which is hereby incorporated by reference.

Introducer sheath 10 also includes optional strain relief member 80 illustrated in Figures 1 and 2. In one embodiment strain relief member 80 is generally cup shaped and configured to cooperate with distal end 23 of hub 20. Strain relief member 80 has a central opening formed therein which is configured to receive elongated tubular member 50 therein. It will be appreciated that the strain relief member 80 may have various other configurations and perform the function thereof as long as is cooperates with distal end 23 of hub 20. In an alternate embodiment, strain relief member 80 and hub 20 are a unitary piece. It will be appreciated that strain relief member 80 and hub 20 may be made from differing materials.

Referring now to Figure 7, there is shown an exemplary embodiment of a dilator 70 that can be utilized in conjunction with the introducer sheath 10 of the present invention. The dilator 70 includes an elongated shaft member 74 having a proximal end 75 and a distal end 76. In one embodiment depicted in Figure 7, the distal end 76 includes a tapered portion 77 configured for entering and expanding an opening in a vessel. The dilator 70 also includes a handle 71 which has a proximal end 72 and a distal end 78. Distal end 78 of handle 71 is coupled to the proximal end 75 of the elongated shaft member 74. A resilient locking feature 73 is formed at the distal end 78 of the handle 71. As shown in Figure 7, the locking feature 73 includes a first deflectable member 79a and a second deflectable member 79b which are configured to be received within the aperture 33 of the cap 30. As illustrated in Figures 4 and 6, in one embodiment the aperture 33 of the cap 30 includes a ridge 34. When the resilient locking feature 73 of the handle 71 is disposed into the aperture 33, the first deflectable member 79a and the second deflectable member 79b resiliently deflect to pass over the ridge 34 until the first and second deflectable members 79a and 79b move back into position, thereby removably locking the handle 71 into place as illustrated in Figure 9. The locking feature 73 of the dilator 70 is advantageous over conventional designs in that the first and second deflectable members allow for more consistent locking and release forces, hi addition, the present invention increases the strength of the attachment between the cap 30 and the dilater 70. It will be appreciated that various other conventional methods for removably attaching the dilator 70 to cap 30 may be utilized. One skilled in the art would appreciate that this could include threaded engagements, and other types of mechanical attachments.

Figure 10 depicts another embodiment of hub 120 in a different embodiment of an introducer sheath of the present invention, m this embodiment, the majority of the components of the introducer sheath 110 that were previously discussed are also compatible with the hub 120. Only the differences will be discussed in detail. The hub 120 includes a main body 121 having a proximal end 122 and a distal end 123 and a central lumen 124 extending therebetween, hi this embodiment of the hub 120 depicted in Figure 10, the central lumen 124 of the hub 120 comprises a first lumen portion 124a and a second lumen portion 124b. The first lumen portion 124a and the second lumen portion 124b have a common central axis. The first lumen portion 124a is proximate to the distal end 123 of the hub 120 while the second lumen portion 124b is proximate to the proximal end 122 of the hub 120. The second lumen portion 124b is sized and confϊgured to receive the flexible membrane 60 and the cap 30 therein. This exemplary embodiment of the hub 120 has eliminated the need for a retainer such as retainer 40 illustrated in Figure 4. In one embodiment, the first lumen portion 124a and the second lumen portion 124a are of differing size. In the embodiment of the hub 120 depicted in Figure 10, in this embodiment the introducer sheath includes a lock ring 190. Figure 11a depicts one exemplary embodiment of a lock ring 190. Lock ring 190 has a distal portion 192 and a proximal portion 194. In one embodiment of the lock ring 190 illustrated, the distal portion 192 has a rounded outer peripheral shape. It will be appreciated that the distal portion 192 could have various other shapes as long as it is shaped and configured to cooperate with first lumen portion 124a. By way of example and not limitation, the shape of distal portion 192 of lock ring 190 could be oval, elliptical or various combinations thereof. The distal portion 194 of the lock ring 190 is configured to cooperate with flared portion 53 of proximal end 52 of tubular member 50. In an exemplary embodiment, the proximal portion 194 of lock ring 190 is flared as illustrated.

In the exemplary embodiment, of the lock ring 190 illustrated in Figure 11a, the lock ring 190 includes posts 196 which are formed on the exterior surface of the lock ring 190. In one embodiment, posts 196 extend along the outer surface of the lock ring 190 and in this embodiment are substantially parallel to the central axis of the introducer sheath. In the exemplary embodiment depicted in Figure 11a, the posts 196 extend on the outer surface of the distal portion 192 of lock ring 190 and along the proximal portion 194 until the angle of the flare intersects them. It will be appreciated that the posts 196 could have differing sizes and lengths. In exemplary embodiment illustrated in Figure 11a, the lock ring 190 has four posts 196 which are equally spaced along the exterior surface of the lock ring. It will be appreciate that differing numbers of posts 196 as well as different spacing of the posts 196 could be utilized. Figure 1 Ib illustrates another embodiment of a lock ring 290 for use in an introducer sheath of the present invention. In this embodiment, lock ring 290 has a distal portion 192 and a flared proximal portion 194 but does not include the posts 196. With the embodiment of introducer sheath which uses a lock ring and eliminates the need for a retainer, the hub 120 is formed using a conventional overmolded platform in which the flared portion 53 of proximal end 52 of tubular member 50 and lock ring 190 are positioned and hub 120 is molded around them, hi one embodiment, the angle of the flare of the flared portion 53 is about 30 to about 35 degrees from the central axis. It will be appreciate that various other angles of the flare for flared portion 53 can be used as long as flared portion 53 is configured to cooperate with lock ring 190 and shoulder area 127. Once molded, the lock ring 190, the flared portion 53 of proximal end 52 of tubular member 50, and hub 120 form a fluid tight seal.

In the embodiment illustrated in Figure 10, the distal end 57 of the tubular member 50 extends outwardly from hub 120. The flared portion 53 of the proximal end 52 of the tubular member 50 is proximate to the shoulder area 127 of the main body 21 of the hub 120. In an exemplary embodiment of the present invention, the beginning of flared portion 53 is located generally proximate to the distal end 123 of the hub 120. It will be appreciate that various lengths of flared portion 53 and locations of the beginning of flared portion 53 can be utilized and still perform the function thereof. The distal portion 192 of the lock ring 190 cooperates with the flared portion 53 of proximal end 52 of tubular member 50. hi this embodiment, the proximal end 122 of the hub 120 is configured to cooperate with the distal end 62 of flexible membrane 60. hi this exemplary embodiment of the hub 120, the second lumen portion 124b is configured to receive flexible membrane 60 therein. As illustrated in Figure 10, the hub 120 has a channel 139 formed therein which is configured to receive the distal end 60 of flexible membrane 60 therein. The remainder of the assembly of the introducer sheath is consistent with that previously discussed. hi accordance with the present invention, an introducer sheath or components thereof can be formed using one or more materials. Typically, the materials used in forming the introducer sheath are medical grade synthetic materials or plastics. Exemplary materials may include, but are not limited to, flexible PVC, polyurethane, silicone, liner low-density polyethylene ("LLDPE"), polyethylene, high density polyethylene, ("DHPE"), polyethylene-lined ethylvinyl acetate ("PE-EVA"), polypropylene, latex, thermoplastic rubber, polytetrafluoroethylene (PTFE), expandable polytetrafluoroethylene (ePTFE), fluoroethylene-propylene (FEP), perfluoroalkoxy (PFA), ethylene-tetrafluoroethylene-copolymer (ETFE), ethylene- chlorotrifluoroethylene (ECTFE), polychloro-trifluoroethylene (PCTFE), polyimide (PI), polyetherimide (PEI), polyetherketone (PEEK), polyamide-imide (PAI)₅ other fluoropolymers, and the like.

Exemplary materials used in the introducer sheath or the components of the sheath can also include elastomers or thermoplastic elastomers. Examples of elastomers include, but are not limited to, natural rubber, silicone rubber, polyurethane rubber, polybutadiene, polyisoprene, chlorosulfonated polyethylene, polysulfide rubber, epichlorohydrin rubber, ethylene propylene rubber, and the like or any combination thereof. These materials provide the elasticity that enable the sheath to expand and/or contract to accommodate the removal/insertion of a medical device as required. Other materials that can be used can include, but are not limited to, dip coated type silicones. In other embodiments, the materials suitable for use in an introducer sheath and the components thereof are configured to have chemical resistance, crack resistance, no toxicity, Food and Drug Administration ("FDA") compliance, non-electrically conductive, dimensional stability, and/or be sterilized by ethylene oxide, gamma radiation, autoclave, UV light, ozone, and the like.

In addition, the selection of materials for a particular introducer sheath or its components can depend on a variety of factors that include, but are not limited to, a particular stiffness and/or flexibility of the sheath or any portion of the sheath, including the desired column stiffness and strength to enable insertion of the sheath, a particular shear or split strength for the sheath or any portion of the sheath, the ability to resist kinking, and the like. For example, the material used for the tubular portion of the introducer sheath may be selected based on shear strength or how easily it can be split. Further, certain features of the sheath may be formed to enhance certain characteristics. For example, a strain relief portion may be formed so as to resist kinking while the elongated tubular portion may be formed to facilitate splitting.

When more than one material is used to form the sheath or to form specific portions of the introducer sheath, the materials may be selected, in addition to the factors identified herein, on a bond strength between the materials or on the elasticity of a particular material. The bond strength, for example, may have an impact on the splitability of the sheath or of a portion of the sheath. The bond strength may also affect the ability of the sheath to expand without splitting.

When an elastomer is used in the sheath or a component of the sheath, the elasticity of the elastomer enables the sheath or a portion of the sheath to at least partially deform, resiliently deform, or elastically expand as needed to accommodate a medical device and then return or substantially return to its configuration prior to deforming or expanding. Advantageously, the ability to deform and/or expand permits a device, such as an expanded or expandable balloon, to be withdrawn through the sheath without removing the sheath, for example from a patient's vasculature. This maintains access to the patient's vasculature without the difficulty of inserting another sheath or medical device through the puncture site. Further, maintaining the introducer sheath in place allows a physician or technician to insert one or more additional medical devices, such as a vessel closure device, using the introducer sheath. It will be appreciated that the introducer sheath will be used in a variety of medical procedures. For example, the introducer sheaths disclosed herein are intended to be utilized in combination with a vessel closure device such as those shown in United States Patent No. 6,197,042 and pending United States Patent Application Number 10/356,214, filed August 8, 2004 entitled "Clip Applier and Methods of Use", which are both assigned to a common owner and are hereby incorporated by reference herein in their entireties. hi one embodiment, the hub 20, the retainer, and the cap, may be constructed of materials such as acrylonitrile butadiene styrene (ABS), polyvinylchloride (PVC), polycarbonate. In one embodiment, the hub 20 is formed through injection molding. Any of the materials may further include glass reinforcement particles mixed therewith, hi an exemplary embodiment, the elongated tubular member 50 is constructed of polytetrafluoroethylene, Teflon, and similar materials, hi one embodiment the tubular member 50 is generally fabricated through extrusion. The tubular member 50 as described herein may be constructed of a single material or may be constructed of more than one material. For example, the tubular member 50 may be constructed of two or more materials by utilizing a co-extrusion process. It will be appreciated by one skilled in the art, that various other materials can be used for these individual components. For example, any of the above identified materials may further include glass reinforcement particles mixed therewith. Further, various other methods of manufacture could be utilized.

Further still, it is contemplated that a geometric feature may be formed within the wall of the tubular member 50. An example of such feature is a sinusoidal pattern formed within the wall of the tubular member 50. The sinusoidal pattern may be beneficial in that it may promote easier splitting of the sheath if desired. Additionally, an introducer sheath having this type of pattern may also reduce friction between the sheath and medical devices disposed through the sheath as the medical device will only contact the sheath at various points along the length of the sheath versus contacting the wall of the sheath along the entire length of the sheath.

In accordance with Figs. 12A through 14C there will be described and alternative embodiment of a sheath in accordance with the present invention. As shown therein and described below the alternative embodiment of the sheath in accordance with the present invention relates to sheaths formed as unitary members as will be described in greater detail below with regard to the appended figures.

An introducer sheath in accordance with the alternative embodiment of the present invention is described herein as having portions or members, though it shall be understood that the introducer sheath as described herein is preferably formed as a unitary member and the portions or members are used herein for clarification. Embodiments of the introducer sheath are depicted in the drawings, which are not necessarily to scale and are not intended to limit the scope of the invention. It will be understood that the benefits of the present invention are not limited to application with an introducer sheath. Rather, other medical devices may be modified based upon the teaching contained herein such that they to can provide the identified functionality. The introducer sheath may be formed, by way of example, using a co-extrusion process or an injection molding process or other method that results in a sheath formed as a unitary member. The process by which an introducer sheath is formed may include the use of one or more materials. The materials can be used simultaneously, or at different stages of the manufacturing process. Typically, the materials used to form the introducer sheath are medical grade synthetics or plastics. Exemplary materials may include, but are not limited to, flexible PVC, polyurethane, silicone, liner low-density polyethylene ("LLDPE"), polyethylene, high density polyethylene, ("DHPE"), polyethylene-lined ethylvinyl acetate ("PE-EVA"), polypropylene, latex, thermoplastic rubber, and the like. In some embodiments, the materials are configured to have chemical resistance, crack resistance, no toxicity, Food and Drug Administration ("FDA") compliance, non-electrically conductive, dimensional stability, and/or be sterilized by ethylene oxide, gamma radiation, autoclave, UV light, ozone, and the like.

In addition, the selection of materials for a particular sheath can depend on a variety of factors that include, but are not limited to, a particular stiffness and/or flexibility of the sheath or any portion of the sheath, including the desired column stiffness and strength to enable insertion of the sheath, a particular shear or split strength for the sheath or any portion of the sheath, the ability to resist kinking, and the like. For example, the material used for the tubular portion of the introducer sheath may be selected based on shear strength or how easily it can be split. Further, certain features of the sheath may be formed to enhance certain characteristics. For example, a strain relief portion may be formed so as to resist kinking while the elongated tubular portion may be formed to facilitate splitting.

When more than one material is used to form the sheath or to form specific portions of the introducer sheath, the materials may be selected, in addition to the factors identified herein, on a bond strength between the materials or on the elasticity of a particular material. The bond strength, for example, may have an impact on the splitability of the sheath or of a portion of the sheath. The bond strength may also affect the ability of the sheath to expand without splitting. As described above, the materials of a sheath may be selected based on a splitting or shear property of the materials. One reason for this characteristic or property relates to use of the sheath in medical procedures. For example, when the sheath is used in conjunction with a medical device during a medical procedure, it may be desirable for the introducer sheath to split or shear during insertion or retrieval of the medical device. This may occur, for example, when a vessel is closed with a vessel closure device. The vessel closure device can be used to attach a clip that effectively seals or closes the entry to the body lumen. As the entry or access to the body lumen is closed, the vessel closure device can apply a force that causes the sheath to split. Embodiments of the invention thus contemplate embodiments of the sheath or of portions of the introducer sheath that facilitate splitting at the appropriate time. Further, embodiments of the sheath contemplate structural features that relate to the ease with which a sheath splits without otherwise impacting the use of the sheath.

In accordance with one embodiment of the present invention, an introducer sheath may include a hub member or hub portion having a proximal end and a distal end. The proximal end of the hub portion can be configured to receive a flexible valve member therein. The sheath further includes an elongated tubular portion generally extending from the distal portion of the hub member. The elongated tubular portion is generally centered with an axis of the hub member and the lumen of the tubular portion is aligned with a lumen of the hub portion because the sheath is formed as a single integrated unit in some embodiments. Alternatively, the lumen of the tubular portion can be aligned with a lumen of the hub portion, whether or not axially aligned. The aligning of the lumens can occur during manufacture, such as when the hub portion and the sheath are formed as a single integrated unit.

Referring now to Figure 12A, there is shown an exemplary embodiment of an introducer sheath 121210. The introducer sheath 1210 can include a hub portion 1220 having a proximal end 1222 and a distal end 1224, and a tubular portion 1230 having a proximal end 1232 and a distal end 1234. The cross section of the hub portion 1220 can be generally cylindrical in nature, although other configurations are contemplated. Exemplary configurations or shapes may include, by way of example, oval, polygonal, elliptical, or other cross-section that can be usable for a medical device that is insertable into a body lumen. The elongate tubular portion 1230 extends from the distal end 1224 of the hub portion 1220. Because the sheath 1210 can be formed as a unitary member, the proximal end 1232 of the tubular portion 1230 can be integrally formed with the distal end 1224 of the hub portion 1220. Because the sheath 1210 can be formed as a unitary member, the hub portion 1220 effectively transitions to the tubular portion 1230. Because the transition between the hub portion 1220 and the tubular portion 1230 may introduce a natural flex point, embodiments of the invention can optionally include a strain relief portion 1240 which smoothly transitions the tubular portion 1230 of the sheath 1210 to the hub portion 1220. The strain relief portion 1240 can be formed at the transition between the hub portion 1220 and the tubular portion 1230. More particularly, the strain relief portion 1240 can be disposed adjacent the distal end portion of the hub portion 1220 and adjacent the proximal end 1232 of the elongate tubular portion 1230. The strain relief portion 1240 can also be configured to provide additional support to at least the proximal end 1232 of the elongate tubular portion 1230 to prevent kinking at the transition zone of the proximal end 1232 of the elongated portion 1230 and the distal end 1224 of the hub portion 1220. hi one embodiment, the strain relief portion 1240 can be formed by gradually increasing a thickness of tubular portion 1230 as the tubular portion 1230 of the sheath 1210 transitions to the hub portion 20 of the sheath. Alternatively, the strain relief portion 1240 can be formed using other structures or formations that provide, for example, support or kink resistance to the transition from the tubular portion 1230 to the hub portion 1220. For instance, the strain relief portion 1240 can include webs, extensions, or other internal or external structures to increase the strength and/or stiffness of the introducer sheath 1210 at the hub portion/tubular portion transition.

With continued reference to Figure 12A, the distal end 1234 of the tubular portion 1230 can also include a tapered portion 1236 that facilitates entry of the introducer sheath 1210, for example, into patient's vasculature or other body lumen. The tapered portion 1236 may be formed after the initial forming process of the introducer sheath 1210 or be formed as part of the initial forming process. For example, the tapered portion 1236 may be formed as part of the extrusion or injection molding processes. Alternatively, the tapered portion 1236 may be formed by heat forming, grinding, milling, laser treatment, etching, or other known methods that result in a thinner wall thickness.

Figure 12B further illustrates a cross sectional view of the sheath 1210 along the line 12B. As shown, a lumen 1228 extends from a proximal end 1222 of the hub portion 1220 to the distal end 1234 of the tubular portion 1230. The lumen 1228 can be generally uniform in cross-section over all or a portion of its length from the proximal end 1222 of the hub portion 1220 to the distal end 1234 of the tubular portion 1230. hi the illustrated configuration, the lumen 1228 has a generally uniform cross-section along its length along the tubular portion 1230, while having a generally uniform cross- section portion and a changing cross-section portion along the length of the hub portion 1220. It will be understood, however, that other cross-sectional configurations are possible so long as they can accommodate a medical device or instrument inserted therein.

With continued reference to Figure 12B, the proximal end 1222 of the hub portion 1220, within the lumen 1228 and defined by the inner wall or surface 1252 forming the lumen 1228, can also include a feature, such as a receiving feature 1226, therein, which is configured to receive a flexible valve member 1250. The valve member 1250 may be inserted after the sheath 1210 is formed. For instance, the receiving feature 1226, such as a groove or channel, can receive the valve member 1250 and retain the same within the hub portion 1220. Optionally, a retaining cap (not shown) disposed adjacent to or within the proximal end of the hub portion 1220 can aid the receiving feature 1226 to retain the flexible valve member 1250 within the hub portion 1220. Alternatively, the valve member 1250 can be integrally formed with the hub portion 1220 during the molding process of the sheath 1210 and as such the hub portion 1220 need not include the receiving feature 1226.

The cooperation between the receiving feature 1226, optional the retaining cap, and/or the valve member 1250 result in a sealed hub portion 1220. Stated another way, the valve member 1250 is self sealing once it is inserted or formed in the hub portion 1220 to prevent fluid escaping from the body lumen.

The valve member 1250 can be one of a variety of different seals, including optionally being self sealing once it is inserted into the hub portion 1220. The valve member 1250, for example, may have an elastomeric body, such as silicone rubber or other material as described above, with at least one slit and/or other collapsible opening formed therein to allow selective insertion and removal of medical instruments, such as guide wires, catheters and other such devices. The collapsible openings or other portions of the valve member 50 maintain a fluid tight seal with or against the medical instrument. Thus, blood or other bodily fluids are prevented from leaking out, and unwanted air is prevented from entering into the body. Examples of such flexible membranes or valve members which can be utilized with the present invention are shown in US Patents No. 4,798,594, 5,176,652, and 5,453,095 the entireties of which are herein incorporated by reference.

With continued reference to Figure 12B, illustrated is an optional port member 1242 that may be formed on the outer surface or outer wall 1244 of the hub portion 1220. The port member 1242 may function as a fluid port for the sheath 1210. Thus, any fluid, such as saline or blood or medication for example, can be added or withdrawn through the port member 1242. The port member 1242 may also be optionally or alternatively configured to align or position any device or instrument (e.g., a vessel closure device, a catheter) used in conjunction with the sheath 1210. The port member 1242 may be shaped so as to interact with an alignment mechanism on a medical device and optionally create a fluid, sealed connection. One exemplary type of port member is a member having a luer lock configuration. It will be understood that other types of port can performed the desired function. Also formed on the outer surface or wall 1244 of the hub portion 1220 can be a retention recess or ring 1246, as shown in Figure 12 A. The recess or ring 1246 may be used to secure a cap (not shown) to the sheath 1210. The recess or ring 1246 can have various configurations to perform the identified and desired function. For instance, although the walls forming the recess or ring 1246 are illustrates as being generally parallel, it will be understood that the recess or ring 1246 can have tapered wall, curved wall, combinations of generally parallel, tapered, or curved wall, or generally any other configuration that would allow a cap to be secured thereto or for the recess. It is contemplated that the wall thickness along the length of the elongate tubular portion 1230 can be varied to vary mechanical properties of the sheath (e.g., kink resistance, stiffness, flexibility and the like). Further, the thickness of the strain relief 1240 (which can vary across the transition between the tubular portion 1230 and the hub portion 1220), the thickness of the hub portion 1220, the diameter of the lumen of the tubular portion 1230 and of the lumen of the hub portion 1220 can also be varied or specifically selected. These dimensions of the sheath 1210 are often controlled and determined during the manufacturing process. In an injection molding process, for example, the sheath 1210 may be formed using a mold. The mold can be machined or configured based on the desired dimensions and configurations of the sheath 1210 as described herein. After the mold (which may include more than one part) is formed, the injection molding process can begin by melting a suitable material, such as one described above, and then injecting the melted material into the mold, often under pressure. The mold used in the injection molding process is typically formed such that the molded introducer sheath can be removed after it has cooled and such that the resulting introducer sheath has the desired dimensions and characteristics described herein. As a result, the molded sheath 1210 can be a unitary member and may not be assembled from separately formed parts. Benefits of forming the introducer sheath 1210 as a unitary member include reduced costs, more accurate parts (i.e. dimension control) due to lack of assembly, as well as the ability to balance mechanical properties across the entire sheath 1210. For example, the thickness of the walls of the hub portion, the tubular portion, the strain relief, the tapered portion, and the like can be controlled and varied as desired. Referring now to Figure 12C, there is shown a cross-sectional view of the sheath 1210 in accordance with the present invention along the line 12C-12C of Figure 12A. In particular, Figure 12C illustrates a cross-sectional view of the elongate tubular portion 1230 of the sheath 1210. The elongate tubular portion 1230 can include an outer wall 1260 and an inner wall 1262 thereby defining a wall thickness. Additionally, the lumen 1228 extends along the length of the tubular portion 1230. The width or diameter of the lumen 1228 can vary and may depend on the intended use of the sheath 1210. Because the hub portion 1220 and the tubular portion 1230 are integrally formed, the lumen 1228 is axially aligned along its length. Stated another way, the axis of the portion of the lumen 1228 within the tubular portion 1230 can be aligned with the axis of the portion of the lumen 1228 within the hub portion 1220. Generally, the outer wall, whether defined by the outer wall 1260 of the tubular portion 1230 or the outer wall 1244 of the hub portion 1220, defines the outer surface or wall of the sheath 1210. Similarly, the inner wall, whether defined by the inner wall 1262 of the tubular portion 1230 or the inner wall 1252 of the hub portion 1220, defines the inner surface or wall and lumen 1228 of the sheath 1210. As mentioned above, although the cross sectional view of the tubular portion 1230 is cylindrical in nature, other cross sectional shapes (polygonal, oval, elliptical, rectangular, etc.) are within the scope of the invention. Further, the lumen 1228 may also have an alternative cross sectional shape other than circular. In one example, the cross sectional shape of the tubular portion 1230 and/or the lumen 1228 can be determined by the mold used in an injection molding process. Further, the cross- sectional configuration of the lumen 1228 need not be the same as that of the cross- section configuration of the tubular portion 1230 as defined by the outer wall of the tubular portion 1230, and more generally the sheath 1210.

Referring now to Figure 13 A there is shown an exemplary embodiment of an alternative introducer sheath in accordance with the present invention. Much of the description related to the sheath 2210 also applies to the embodiment of the sheath 2210, and vice versa. The alternative embodiment of the sheath will herein be described as having portions similar to that as described above.

As shown in Figure 13 A, the sheath 2210 can include a hub portion 2120 having a proximal end 2122 and a distal end 2124, and a tubular portion 2130 having a proximal end 2132 and a distal end 2134. Extending from the proximal end 2122 to the distal end 2134 is a lumen 2128. Generally, the configuration of the lumen 2128 and the inner wall or surface forming the lumen 2128 is different from that described with respect to lumen 1228 (Figure 12B). A portion of the lumen 2128 in the hub portion 2120, or the inner wall or surface 2152 can have a stepped configuration. The stepped configuration can include a first portion 2154 having a first inner diameter and a second portion 2156 having a second diameter larger than the first diameter. This stepped configuration, or the transition between the first portion 2154 and the second portion 2156 provides or functions as a stop for an inserted valve member 2150. The valve member 2150 can be secure within the lumen 2128 through a friction or interference fit with the inner surface or wall 2152 of the hub portion 2120. Alternatively, or in addition to the friction or interference fit, the valve member 2150 can be mounted within the lumen 2128 through adhesives, thermal or chemical bond, mechanical coupling, such as, but not limited to, through the use of a groove or recess in the inner surface or wall 2152, or other technique used to mount two components together. In one configuration, a retaining cap 2170, having a lumen 2172 that can receive a medical device or instrument to be inserted through the valve member 2150 and the lumen 2128, can secure the valve member 2150. The proximal end 2174 of the retaining cap 2170 can align with, overlap, or be recessed relative to the proximal end 2122 depending upon the particular configuration of the end cap 2170. With reference to Figures 13A and 13B, the elongated tubular portion 2130 includes an outer surface or wall 2160 and an inner surface or wall 2162. Formed in the inner wall 2162 is at least one longitudinal groove 2164, and more generally a geometric pattern of grooves, channels, recesses, or other structures, that can extend along an axis parallel to axis extending through the center of the sheath, and centered within the lumen 2128. With one or more longitudinal grooves 2164, the longitudinal grooves 2164 can be formed in various patterns and orientations to provide different characteristics to the tubular portion 2130. It is contemplated that additional styles and types of patterns may be utilized in accordance with the present invention. For example, one or more longitudinal grooves 2164 may form a sinusoidal pattern disposed about the inner radius of the elongate tubular portion 2130. Alternatively, the one or more longitudinal grooves 2164 may be configured to run along a different axis than one parallel to an axis extending along the center of the sheath 2210. For example, the one or more longitudinal grooves 2164 may be formed as one or more spirals as illustrated in Figure 13C. The one or more longitudinal grooves 2164 may also only extend partially along the length of the elongated portion 2130. In another embodiment, the one or more longitudinal grooves 2164 may extend beyond the tubular portion 2130 and into the hub portion 1220 (Figure 12A). In another example, the one or more longitudinal grooves 2164 may not extend into the tapered portion of the tubular portion 2130. Generally, it should be understood that the above described configuration of the at least one groove 2164 should be considered exemplary and not limiting in any manner. It is contemplated that additional styles and types of patterns may be utilized in accordance with the present invention. For instance, one configuration of the longitudinal grooves 2164 can provide increases column stiffness, while another configuration can provide kink resistance and/or resistance to torsional loads. Further, it should be understood that the inner wall 2162 can have patterns or configurations of structures other than grooves to achieve desired configurations. For instance, and not by way of limitation, other dents, extensions, channels, recesses, or other structural formations can be created upon or in the inner wall 2162.

The formation of the geometric pattern of the plurality of grooves 2164, for example, can be formed by machining a corresponding feature in the mold and subsequently using the mold during compression molding, injection molding, blow molding, rotational molding, and/or molding or fabrication processes. As a result, the geometric pattern can be automatically formed during the manufacturing process and no additional steps or acts are required to form the geometric pattern on the inner wall 2162. Referring now to Figure 14A there is shown an exemplary embodiment of an alternative introducer sheath in accordance with the present invention. Much of the description related to sheath 1210 and sheath 2120 also applies to the embodiment of the sheath 2200, and vice versa. The alternative embodiment of the sheath will herein be described as having portions similar to that as described above. As shown in Figure 14A, the sheath 2200 includes a hub portion 2220 having a proximal end 2222 and a distal end 2224. The sheath 2200 further includes a composite elongate tubular portion 2230 extending from the distal end 2224 of the hub portion 2220. In this example, the elongated portion 2230 is generally tubular in construction and includes a proximal end 2232 and a distal end 221234. As described above, the cross sectional shape of both the portion 2230 and the hub portion 2220 can be any shape, such as by way of example, circular, elliptical, square, polygonal, and the like. In this example, however, the tubular portion is composite and can be formed from more than one material.

The sheath 2200 may additionally include a feature formed within the hub portion 2220 which is configured to receive a flexible valve member (such as the valve member 1250 in Figure 12B or valve member 2150 in Figure 13A). The flexible valve member may be integrally formed into the hub portion during the molding process of the sheath 2200 or may be held within the hub portion 2220 using the techniques or methods described herein. Alternatively, the hub portion 2220 of the sheath 2200 can be molded so as to provide the elements needed to hold the valve member in place after insertion. The receiving feature 226 (Figure 12B) or the stepped configuration illustrated in Figure 13A are examples of features that can retain the valve member after insertion into the hub portion 2220.

Turning now to the tubular portion 2230, and with reference to Figures 14A and 14B, disposed within at least a portion of the tubular portion 2230 is at least one groove 2280, with one being shown in the illustrated configuration. This groove 2280 can receive an insert 2282 to provide certain characteristics and properties to the tubular portion 2230. For instance, the insert 2282 can provide structural stiffness or kink resistance to the tubular portion 2230 and/or the introducer sheath 2200. The groove 2280 can extend from (i) the outer surface or wall 2260 to the inner surface or wall 2262, (i) the outer surface or wall 2260 toward the inner surface or wall 2262, or (iii) the inner surface or wall 2262 toward the outer surface or wall 2260. As shown in Figures 14A and 14B, the groove 2280 and/or the insert 2282 can extend from the tubular portion 2230 to the hub portion 2220. Generally, the groove 2280 and/or the insert 2282 can extend from a portion of the tubular portion 2230 to a portion of the hub portion 2220. Alternatively, the groove 2280 and/or the insert 2282 may be formed only in the tubular portion 2230, only in the hub portion 2220, or in a portion of the hub portion 2220 or the tubular portion 2230. In other embodiments, one or more grooves 2280 and/or inserts 2282 can be formed in the sheath 2200. It will be understood that although reference is made to a groove herein other geometric patterns or configurations of channels, recess, holes, or other structures formed in the sheath can be used. Further, it will be understood that a line or other geometric pattern scored or formed in the sheath, with or without the inclusion of the insert can function in a similar manner to the groove and insert as described herein. With continued reference to Figures 14A and 14B, the insert 2282 can be formed in the groove 2280 in a variety of manners. In one configuration, the groove 2280 can be formed as part of the initial molding process. For instance, the sheath 2200 can undergone a first injection molding process where the hub portion 2220 and elongated portion 2230 are formed as a single unitary unit, with the groove 2280 being formed at that time. The mold used to form the sheath 2200 can then be adapted, such as by removing the portion of the mold that was responsible for the groove 2280, and a second injection molding process can then be performed to inject a second material into the groove 2280 to form the insert 2282. The insert 2282 effectively bonds to the material defining the groove 2280 resulting in the sheath, the sheath being a unitary member. One example of a molding technique that can be used to perform the above described process is an over-molding injection molding process. It is also contemplated that the first and second injection molding processes can be conducted simultaneously or within a time period of each other, for instance by way of an over-molding injection molding process or a 2-shot injection molding process. In one configuration, a mold can be manufactured and placed into an injection molding machine, wherein the first molding process can form the sheath including the groove 2280 shown in Figure 14A and a second molding process would form the completed sheath by filling the groove 2280 with a second material to form the insert 2282, resulting in the configuration of Figure 14B. Thus, the tubular portion 2230 can be a composite. The process times can be controlled depending upon the materials to be molded and the desired mechanical properties. With reference to Figure 14B, shown a cross-sectional view of the elongated portion 2230 taken about line 14B-14B of Figure 14A. The cross sectional view of Figure 14B illustrates the tubular portion 2230 after the groove 2280 has been formed and filled with a second material, which forms the insert 2282. As shown in Figure 14B, the elongate tubular portion 2230 has an outer wall 2260 and an inner wall 2262 thereby defining a lumen 2228 as well as a wall thickness. The insert 2282 is shown disposed in groove 2280 thereby forming a continuous generally tubular cross-section, hi one configuration, the inner wall or surface 2262 of the elongated portion 2230 typically remains smooth after the second material is injected into the groove 2280 to form the insert 2282. Alternatively, the inner surface 2262 of the elongated portion 2230 can have one or more variations, at least one of which can be defined by the insert 2282 within the groove 2280. For instance, during the process of applying or depositing the second material the mold defining the boundaries for the second material 2282 can include the desired pattern of the portion of the inner wall or surface 2262 associated with the insert 2282. As previously described above, the second material, as well as the first material, may be chosen based upon desired mechanical properties for the sheath 2200. For example, it may be desirable to produce an elongated portion 2230 which is easily splitable along a portion of the interface between the first and second materials or through the second material in response to an adequate applied force. In this case, the bond between the first material and the second material can be adjusted through the manufacturing process. As previously stated, the first and second materials may be selected according to the bond between the first material and the second material and on the splitability of the first and/or second materials. For example, the thickness of the first material at the interface with the second material can be less than the thickness of the first material at other locations. This, combined with a second material that fills the groove 2280 to form the insert 2282 and has less strength than the first material, provides a sheath that has particular properties. For example, the tubular portion 2230 may be more likely to split along the groove 2280 or along any other geometric pattern formed on the inner wall of the tubular portion 2230, whether or not filled with a second material or the insert 2282. In instances where the geometric pattern such as the groove 2280 is filled with a second material to form the insert 2282, a bond may be formed automatically during the molding process. Alternatively, thermal bonding, chemical bonding, or other known technique can be used to facilitate bonding between the similar or dissimilar medical grade materials forming the insert 2282 and the remainder of the sheath 2200. As illustrated above, mechanical properties of the tubular portion may be adjusted by forming the elongate tubular portion 2230 as a composite member. For example, if it is desirable to produce a sheath that is splitable during use, the second material and the insert 2282 may be weaker than the first material, thereby forming a joint wherein the sheath may be easily split by an applied force. Alternatively, the second material or insert 2282 can be utilized to stiffen or weaken the overall tubular portion 2230. This can be used to prevent kinking, and the like. Alternatively, the second material or insert 2282 can be used to stiffen or weaken the overall tubular portion 2230 and assist in splitting the sheath during use. For example, the second material or insert 2282 may provide stiffness and cause the tubular portion 2230 to split at the groove or other geometric pattern in response to an applied force, such as the withdrawal of a medical device like a vessel closure device. Although the alternative embodiment has been described with respect to specific geometries as well as construction methods this should not be considered limiting in any manner. For example, it is contemplated that the groove 2280 may be formed having many different geometric shapes and patterns as well as lengths. Additionally, the groove may include a geometric feature formed along the length thereof, wherein the second material or insert 2282 would fill into this feature, thereby interlocking the two materials together.

Figure 14C, for example, illustrates another configuration of the interface between a first material and a second material or between the groove and an insert, hi particular, the groove 2280 includes sub-grooves 2284 that extend outwardly from the main portion of the groove 2280. These sub-grooves 2284 can receive or be filled with the second material that forms the insert 2282 during the injection molding process and provide a mechanical connection or coupling between the two materials and between the groove 2280 and the insert 2282. As such, the sub-grooves 2284, together with the insert 2282 or second material deposited therein, function as interlocking features that mechanical tie the portions of the tubular portion 2230 together. By so doing, the two portions of the tubular portion 2230 can be mounted or coupled together through both the bonding of the two materials and the mechanical coupling of the interlocking features formed in the groove 2280 and the insert 2282. It will be understood that in another configuration, the insert 2282 can be formed separately from the remainder of the sheath 2200. The insert 2282 can then be mounted or coupled to the groove 2280 during subsequent processing. For instance, the insert 2282 can be mounted or coupled to the groove 2280 using adhesives, thermal or chemical bonding, or other techniques to mount or couple similar or dissimilar medical grade materials. Further, the insert 2282 can mount or couple using mechanical structures, such as but not limited to, the interlocking features, with or without the use of adhesives, thermal or chemical bonding, or other techniques to mount or couple similar or dissimilar medical grade materials. Because the sheath can be formed by an injection molding process using molten or melted material, the shape of the sub-grooves 2284, or other mechanical structures that facilitate mechanical coupling between two components, can vary and accommodate any desired purpose. In some instances, the formation or filling of the groove 2280 with the second material to form the insert 2282 may cause the first material to melt, thereby causing the two materials to bond. For example, the shape of the feature 2284 may include extensions that prevent the first material from separating from the second material without tearing or shearing. This can strengthen the bond, in one example, between the first and second materials. Further, the interlocking feature may ensure that the tubular portion shears at the groove 2280 owing to the strength or lack thereof of the second material. The at least one interlocking features illustrated in Figure 3C can extend from a proximal end 2232 to a distal end 2234 of the tubular portion 2230 and/or the introducer sheath 2200. It will be understood, however, that the at least one interlocking feature can extend only part way from the distal end toward the proximal end, from the proximal end to the distal end, or at any location along the length of the tubular portion 2130 and/or the sheath 2200. In addition to the use of a second material to fill the groove 2280 or other geometric pattern, it is further contemplated that more than two materials may be utilized to form the introducer sheath in accordance with the present invention or that other portions of the sheath may be formed from a second material. For example, a first material maybe utilized to form the hub portion and one or more materials (which may include the first material) may be utilized to form the elongated portion of the sheath. Again, the selection of materials may depend on the end use of the sheath, properties of medical devices used with the sheath, and the like or any combination thereof. Although the present invention has been shown and described in accordance with specific embodiments these should not be considered limiting in any manner. For example, multiple materials may be utilized to form a unitary sheath in accordance with the present invention, wherein multiple injection molding processes are performed simultaneously or in stages to form the unitary sheath in accordance with the present invention. Embodiments of the invention relate to a device that is expandable to cooperate with medical devices that may have become enlarged in dimension during use. For instance, in one configuration, the device can be an expandable introducer sheath that can accommodate removal of enlarged medical devices without removing the introducer from the delivery site. As such, the sheath or at least a portion of the introducer sheath can expand to accommodate the introduction and/or removal of medical devices that could not ordinarily be accommodated in conventional sheaths. At the same time, the sheath can be formed to have desirable stiffness, kink resistance, and/or flexibility for insertion and positioning in at least a portion of a body lumen. Embodiments of the sheath are depicted in the drawings, which are not necessarily to scale and are not intended to limit the scope of the invention. It will be understood that the benefits of the present invention are not limited to application with an introducer sheath. Rather, other medical devices may be modified based upon the teaching contained herein such that they to can provide the functionality of accommodating removal of enlarged medical devices.

Turning to the introducer sheath in accordance with the present invention, the sheath will be described herein as having portions or members, though it shall be understood that the sheath as described herein can be formed as a unitary unit, formed, by way of example, using a co-extrusion process or an injection molding process, or a sheath fabricated from the assembly of separate parts. As such, the various members or portions are used herein for clarification only and in no way limit the applicability of description herein to other configurations of the sheath and/or medical devices. Generally stated, an exemplary introducer sheath can include a hub member or portion having a proximal end and a distal end. The proximal end of the sheath can be configured to receive a flexible valve member therein. The sheath can further include an elongated tubular member or portion generally extending from the distal portion of the hub portion. The elongated tubular portion, in one configuration, can be generally axially aligned with an axis of the hub portion, with the lumen of the tubular portion being aligned with a lumen of the hub portion. Alternatively, the lumen of the tubular portion can be aligned with a lumen of the hub portion, whether or not axially aligned. The aligning of the lumens can occur during manufacture, such as when the hub portion and the sheath are formed as a single integrated unit or when separate components are joined together. In one embodiment, the tubular portion is configured to expand while still providing the necessary stiffness and/or kink resistance to the sheath. An introducer sheath or portions thereof can be formed using one or more materials. Typically, the materials used in forming the introducer sheath are medical grade synthetic materials or plastics. Exemplary materials may include, but are not limited to, flexible PVC, polyurethane, silicone, liner low-density polyethylene ("LLDPE"), polyethylene, high density polyethylene, ("DHPE"),₍ polyethylene-lined ethylvinyl acetate ("PE-EVA"), polypropylene, latex, thermoplastic rubber, polytetrafluorethylene (PTFE), expandable polytetrafluorethylene (ePTFE), fluroethylene-propylene (FEP), perfluoralkoxy (PFA), ethylene-tetrafluoroethylene-copolymer (ETFE), ethylene- chlorotrifluoroethylene (ECTFE), polychloro-trifluoroethylene (PCTFE), polyimide (PI), polyetherimide (PEI), polyetherketone (PEEK), polyamide-imide (PAI), other fluoropolymers, and the like.

Exemplary materials used in the sheath or a portion of the sheath can also include elastomers or thermoplastic elastomers. Examples of elastomers include, but are not limited to, natural rubber, silicone rubber, polyurethane rubber, polybutadiene, polyisoprene, chlorosulfonated polyethylene, polysulfide rubber, epichlorohydrin rubber, resilin, ethylene propylene rubber, and the like or any combination thereof. These materials provide the elasticity that enable the sheath to expand and/or contract to accommodate the removal/insertion of a medical device as required. Other materials that can be used can include, but are not limited to, dip coated type silicones. In other embodiments, the materials suitable for use in an introducer sheath are configured to have chemical resistance, crack resistance, no toxicity, Food and Drug Administration ("FDA") compliance, non-electrically conductive, dimensional stability, and/or be sterilized by ethylene oxide, gamma radiation, autoclave, UV light, ozone, and the like. In addition, the selection of materials for a particular sheath can depend on a variety of factors that include, but are not limited to, a particular stiffness and/or flexibility of the sheath or any portion of the sheath, including the desired column stiffness and strength to enable insertion of the sheath, a particular shear or split strength for the sheath or any portion of the sheath, the ability to resist kinking, and the like. For example, the material used for the tubular portion of the introducer sheath may be selected based on shear strength or how easily it can be split. Further, certain features of the sheath may be formed to enhance certain characteristics. For example, a strain relief portion may be formed so as to resist kinking while the elongated tubular portion may be formed to facilitate splitting.

When more than one material is used to form the sheath or to form specific portions of the introducer sheath, the materials may be selected, in addition to the factors identified herein, on a bond strength between the materials or on the elasticity of a particular material. The bond strength, for example, may have an impact on the splitability of the sheath or of a portion of the sheath. The bond strength may also affect the ability of the sheath to expand without splitting. When an elastomer is used in the sheath or a portion of the sheath, the elasticity of the elastomer enables the sheath or a portion of the sheath to at least partially deform, resiliently deform, or elastically expand as needed to accommodate a medical device and then return or substantially return to its configuration prior to deforming or expanding. Advantageously, the ability to deform and/or expand permits a device, such as an expanded or expandable balloon, to be withdrawn through the sheath without removing the sheath, for example from a patient's vasculature. This maintains access to the patient's vasculature without the difficulty of inserting another sheath or medical device through the puncture site. Further, maintaining the introducer sheath in place allows a physician or technician to insert one or more additional medical devices, such as a vessel closure device, using the introducer sheath.

Referring now to Figure 15, there is shown an exemplary embodiment of an introducer sheath 3100. The introducer sheath 3100 can include a hub portion 3102, which can include a proximal end 3116 and a distal end 3114, and a tubular portion 3104. Extending from the proximal end 3116 toward the distal end 3114 is a lumen 3110. This lumen 3110 can cooperate with a medical device (not shown), such as a vessel closure device, insertable therethrough. In the illustrated configuration, the lumen 3110 tapers or transitions from one cross-sectional configuration to another cross-sectional configuration near the distal end 3114 to meet or intersect with a lumen 3112 of the tubular portion 3104. It will be understood that the lumen 3110 can have a generally uniform cross-section along its length rather than tapering at its distal end. More generally, the lumen 3110 can include one or more transitional portions based upon the desired configuration and use with other medical devices.

The elongated tubular portion 3104 of the introducer sheath 3100 can extend from the distal end 3114 of the hub portion 3102. The tubular portion 3104 can include a distal end 3120 and a proximal end 3118. The proximal end 3118 can be integrally formed with the distal end 3114 of the hub portion 3102 or can be mounted or coupled to the distal end 3114 through a friction fit, mechanical bonding, adhesives, thermal or chemical bonding, combinations thereof or other manufacturing technique usable to mount, couple or attach two medical components. The distal end 3120 of the tubular portion 3104 can optionally include a tapered portion 3106 to facilitate insertion into a body lumen. This tapered portion 3106 may be formed during or after the initial forming process of the introducer sheath 3100. For instance, when the introducer sheath 3100 is formed through a molding or extrusion process, the tapered portion 3106 can be formed as part of this process. Alternatively, the tapered portion 3106 may be formed by heat forming, grinding or other known methods that result in a thinner wall thickness following the above-described molding or extrusion process or as part of a milling, machining, or similar process.

Optionally disposed at the transition between the hub portion 3102 and the tubular portion 3104 is a strain relief portion 3108. The strain relief portion 3108 would be disposed adjacent the distal end 3114 of the hub portion 3102 and adjacent the proximal end 3118 of the elongate tubular portion 3104. The strain relief 3108 would be configured to provide additional support to the proximal end 3118 of the elongated shaft 3104 to prevent kinking at the transition between the proximal end 3118 of the elongated member 3104 and the distal end 3114 of the hub portion 3102. In one embodiment, the strain relief portion 3108 can be formed by gradually increasing a thickness of tubular portion 3104 at the transition between the tubular portion 3104 and the hub portion 3102. In other configurations, the strain relief portion 3108 can include webs, extensions, or other internal or external structures to increase the strength and/or stiffness of the introducer sheath 3100 at the hub portion/tubular portion transition. The tubular portion 3104 of the introducer sheath can be expandable. More specifically, in the illustrated configuration of Figure 15, the tubular portion 3104 is of an elastomeric material that allows the diameter of the tubular portion 3104 to change as a medical device is inserted or removed from within the lumen 3112. The elastomeric material enables the tubular portion 3104 to expand/contract or deform/reform, while maintaining sufficient column stiffness or strength so that the introducer sheath 3100 can be inserted into the body lumen. In one configuration, the elastomeric material can be any of those described herein and such others as would be identified by one skilled in the art in light of the teaching contained herein.

Optionally, the tubular portion 3104 may also be configured to expand to a certain diameter at which point the tubular portion 3104 is further configured to split or separate into one or more portions to accommodate other medical devices, such as, but not limited to vessel closure devices, as will be described in more detail hereinafter. Generally, each of the hub portion 3102 and the tubular portion 3104 can have at least a portion of which that is generally cylindrical in nature. Although portions 3102 and 3104 can have generally cylindrical portions, other cross-sectional configurations are possible, such as but not limited to, oval, polygonal, elliptical, or other cross-sectional configurations usable for a medical device that is insertable into a body lumen. As previously described herein, the introducer sheath 3100 may be formed through an injection molding process. In an injection molding process, the hub portion 3102 and the elongated tubular portion 3104 are generally formed as a unitary member. Benefits of forming the introducer sheath 3100 as a unitary member include reduced costs, increased accuracy of part dimensions (i.e. dimension control) due to lack of assembly, alignment between the lumen 3112 of the tubular portion 3104 and the lumen 3110 of the hub portion 3102, and the balancing of mechanical properties across the entire sheath 3100 or of any particular portion or member of the sheath 3100. The thickness of the walls of the hub portion 3102 and/or of the tubular portion 3104 can also be controlled and varied as desired during the injection molding process. Although reference is made herein to fabrication of the introducer sheath 3100 through use of injection molding techniques, one skilled in the art will appreciate that various other techniques can be used. For instance, the introducer sheath can be fabricated using milling, grinding, laser treatment, etching, or other techniques to form the introducer from a piece of material. Further, other techniques or methods can include those techniques used by those skilled in the art to fabricate medical devices. With continued reference to Figure 15, disposed within the hub portion 3102 is a flexible valve member 3122 disposed in the hub portion 3102. The valve member 3122 may be integrally formed into the hub portion 3102 during the molding process of the sheath 3100, or may be inserted after the sheath 3100 is integrally formed. For instance, the hub portion 3102 can included a receiving feature 3126, such as a groove or channel, to receive the valve member 3122. The cooperation between the receiving feature 3126 and the valve member 3122 result in a sealed hub portion 3102. Stated another way, the valve member 3122 is self-sealing once it is inserted into the hub portion 3102 to prevent fluid escaping from the body lumen.

The valve member 3122 can be a seal and can have a variety of different configurations to seal the sheath 3100. The valve member 3122, for example, may have an elastomeric body, such as silicone rubber, with at least one slit and/or other collapsible openings formed therein to allow selective insertion and removal of medical devices or instruments, such as guide wires, catheters, balloon pumps, and other such, devices. At the same time, the material and/or structure of the valve member 3122 maintains a fluid tight seal around the medical devices or instruments. Thus, blood or other bodily fluids are prevented from leaking out, and unwanted air is prevented from entering into the body.

It will be understood that the valve member 3122 can be mounted or coupled to the hub portion 3102 in a number of other manners to achieve the sealed configuration for the hub portion 3102. For instance, the valve member 3122 can be retained with a retaining cap (not shown) disposed adjacent the proximal end of the hub portion 3102. In still another configuration, one or more flexible valves or valve members can be mounted within or to the proximal end 116 of the hub portion 3102 through the use of one or more retaining caps, rings, or members know to those skilled in the art. Although illustrated as a single member, the valve member 3122 can be formed of multiple parts to provide the desired fluid sealing capabilities. Exemplary flexible membranes or valve members which can be utilized with the present invention are shown in U.S. Patents No. 4,798,594, 5,176,652, and 5,453,095 the entireties of which are herein incorporated by reference.

More generally, the introducer sheath can have a configuration similar to the introducer sheath disclosed in United States Provisional Patent Application Serial Nos. 60/659,602, filed June 30, 32005, and entitled "Introducer Sheath"; and 60/695,464, filed June 30, 32005, and entitled "Modular Introducer Sheath; and co-pending United

States Patent Application Serial Nos. , filed June 28, 32006, and entitled

"Modular Introducer and Exchange Sheath," (Attorney Docket No. 16497.12.1) and , filed June 28, 32006, and entitled "Introducer Sheath") (Attorney Docket No. 16497.13.1), the disclosures of which are herein incorporated by reference. As such, the valve member 3122 can be mounted in the hub portion 3102 and the tubular portion 3104 can have a similar configuration to the tubular member to the introducer sheath described in the above-identified applications. Figure 15 also illustrates an optional port member 3124, such as a luer port/fitting, which may be formed on the hub portion 3102. The port member 3124 may function as a fluid port for the sheath 3100. Fluid (e.g., blood, antibiotics, plasma, saline, etc.) can thus be introduced and/or extracted through the fluid port 3124. The port member 3124 may also be optionally configured to align and/or selectively lock any device (e.g., a vessel closure device, a catheter) used in conjunction with the sheath 3100. Figures 16-19 illustrate various configurations of the tubular portion of the introducer sheath of the present invention. During the insertion/extraction of a medical device or instrument, the tubular portion can deform/form or expand/contract as needed. Thus, the cross sectional area of the tubular portion may change during a medical procedure. In one example, the tubular portion can expand in diameter from a first position to a second position having a diameter greater than the first position as a medical device is either withdrawn or inserted therethrough. The tubular portion can also return to or substantially to the first position following withdrawal or insertion. The illustrated configurations of the tubular portion each have a sheath portion and an elastic portion to provide the desired elasticity, stiffness, or strength. The sheath portion and the elastic portion can be formed from different materials as illustrated in Figures 15-18 discussed below. Alternatively, and as illustrated in Figure 19, the tubular portion can be fabricated from a single material, with the elastic portions being defined through the formation of lumens in the tubular portion. The inclusion of lumens or of elastomeric materials in the formation of an introducer sheath enable the sheath to deform/form or expand/contract as described herein. Although various features are illustrated in each Figure, any of the features in a particular Figure can be combined with features illustrated in another Figure. Further, the sheath portion and/or elastic portion are examples of one structure capable of performing the function of means for expanding a tubular portion to accommodate the insertion or removal of a medical device. Turning now to Figure 16, illustrated is a tubular portion, identified by reference numeral 3200, which can be used with the introducer sheath of the present invention, i.e., can function as the tubular portion 3104 of Figure 1, i.e., function to expand/contract or deform/reform to enable withdrawal of a medical device that may have enlarged in diameter during use. . The tubular portion 3200 can include at least one sheath portion 3204 and at least one elastic portion 3202. The sheath portion 3204 is typically formed of a first material and the elastic portion 3202 is often formed of a second material. In Figure 16, the sheath portion 3204 can be formed in strips that run along the length of the tubular portion 3200 from the distal end 3220 to the proximal end 3218, although the strips may have a shorter length. In some embodiments, the strips extend into the distal end 3114 (Figure 15) of the hub portion 3102 (Figure 15). The elastic portion 3202 can be formed in strips in this embodiment such that each strip of the elastic portion 3202 is adjacent to strips of the sheath portion 3204. The elastic portion 3202 can be an elastomer that is bonded to the sheath portion 3204. In Figure 16, each strip of the elastic portion 3202 is bonded on each side to adjacent strips of the sheath portion 3204. The elastic portion 3202 enables the tubular portion 3200 to expand or deform such that the interior diameter or cross-sectional area of the lumen can change or increase. The diameter or cross sectional area of the lumen 3212 can expand in certain locations and is not required to expand along the entire length of the tubular portion 3200. Further, different portions of the tubular portion 3200 may expand at different rates and/or at different times. The actual expansion of the tubular portion 3200 can depend on a particular medical device that is inserted or withdrawn and/or the material used to form the tubular portion 3200. The sheath portion 3204 can be selected to ensure that the lumen does not collapse when the tubular portion 3200 is in a first or normal or unstressed position and to provide stiffness or rigidity to the tubular portion 3200. Thus, the sheath portion 3204 provides rigidity, flexibility, and the like or any combination thereof, m some embodiments, the sheath portion 3204 may also provide some elasticity to the tubular portion 3200. Typically, however, the elastic portion 3202 has more elasticity than the sheath portion 3204. Figure 16 also illustrates an optional entry portion 3228 to the lumen 3212 of the tubular portion 3200. The entry portion 3228 can be shaped so as to facilitate entry of any device that is entering the tubular portion 3200 through the entry portion 3228. The entry portion 3228 can be formed when the tapered portion 3206 is formed and the slope of the tapered portion 3206 may be optionally altered to accommodate the entry portion 3228. By shaping the entry portion 3228, any device being withdrawn can more easily enter the lumen 3212 of the tubular portion 3200. In one embodiment, the entry portion 3228 is concave and the edges at the distal end of the tubular portion 3200 are smoothed, hi other configurations, the entry portion 3228 can be generally curved, smooth, or other configuration to aid with withdrawal of a medical device into the lumen 3212. The elongated tubular portion 3200 can include an outer wall 3208 and an inner wall 3210 thereby defining a wall and a thickness of the wall. As with the lumen 3212 (Figure 15), the lumen 3212 extends along the length of the tubular portion 3200. The width or diameter or cross sectional area of the lumen 3212 can vary and may depend on intended use of the sheath 3100. More particularly in this embodiment, the width or diameter or cross sectional area of the lumen 3212 can vary or expand and contract during use as the elastic portion 3202 changes shape, such as stretching and contracting. Because the hub portion 3102 (Figure 15) and the tubular portion 3200 are integrally formed in one configuration, the lumen 3212 of the tubular portion 3200 remains aligned with the lumen 3110 (Figure 15) of the hub portion 3102 (Figure 15) even though the lumen 3212 expands, contracts, deforms, or reforms. It is contemplated that the wall thickness along the length of the elongated tubular portion 3200 can be varied to vary mechanical properties of the sheath (stiffness, kink resistance, column strength, etc.).

Figure 17 illustrates a cross section of the tubular portion 3200 of the introducer sheath as it moves from first, normal, or unstressed position to a second, expanded, or stressed position of the tubular portion 3200. In the first position, identified by reference letter A, the elastic portion 3202 of the tubular portion 3200 is in a contracted or relaxed state and is bonded to the material of the sheath portion 3204 at the bond points 3230. The sheath portion 3204 can be typically formed from a material such that the lumen 3212 of the tubular portion 3200 does not seal or close or collapse in the first position, and/or to provide stiffness or flexibility to the tubular portion 3200.

In the second position, identified by reference letter B, the elastic portion 3202 is expanded while the sheath portion 3204 has not expanded (or has expanded less than the elastic portion 3202) but is still bonded to the material at the bonds 3230. In one embodiment, the sheath portion 3204 may have some elasticity, but is generally configured to have less elasticity than the elastic portion 3202. The bond strength at the bond 3230 may be selected to permit the expansion of the tubular portion 3200 to a predetermined diameter or by a predetermined amount. When that diameter or amount is exceeded, the tubular portion 3200 may split at the bonds 3230 or at another location. In some embodiments, a geometric pattern 3232 is formed on the inner wall 3210 or inner surface of the tubular portion 3200, such as over all or at least one portion of the inner wall 3210 or inner surface. Further, the geometric pattern 3232 can be formed in or on the elastic portion 3202 and/or the sheath portion 3204. This geometric patter 3232 can be used to impart certain desirable mechanical properties to the tubular portion 3200, such as, but not limited to, stiffness, strength, kink resistance, or flexibility to the tubular portion 3200.

Various structures and configurations of the geometric pattern 3232 can be used to provide the desired mechanical properties. For instance, in the illustrated configuration, the geometric pattern 3232 is formed on one portion or surface of the inner wall 3210 of the sheath portion 3204 though use of one or more grooves or recesses. The illustrated geometric pattern 3232 can represent a plurality of longitudinal grooves extending along an axis parallel to the longitudinal axis of the introducer sheath in a generally uniformly distributed pattern. In other configurations, however, the geometric pattern 3232 can be unevenly distributed or a combination of uniformly and unevenly distributed over all or a portion of the inner wall 3210 of the tubular portion 3200. Further, the location of the grooves need not be parallel to the longitudinal axis of the introducer sheath, but can be transverse to such an axis and/or at any other angular orientation relative to the longitudinal axis.

It shall be understood that the pattern 3232 as shown in Figure 17 should be considered exemplary and not limiting in any manner. It is contemplated that additional styles and types of patterns may be utilized in accordance with the present invention. For example, the pattern 3232 may be a sinusoidal pattern disposed about the inner radius of the tubular portion 3200. Alternatively, the pattern 3232 may be configured to run along a different axis than one parallel to the longitudinal axis of the introducer sheath. For example, the pattern 3232 may be formed as a spiral. The pattern 3232 may also only extend partially along the length of the tubular portion 3200. Further, the pattern 3232 can extend along the length of the tubular portion 3200 from the proximal end 3220 to the distal end 3218 or along a portion of the length of the tubular portion 3200. The pattern 3232, or any portion thereof, may terminate prior to the proximal end 3220 of the tubular portion 3200 or extend partially into the hub portion 3102 (Figure 1). The pattern 3232 may also be a separation line, such as a pre- scored line. The pattern 3232 may be designed to facilitate splitting of at least a portion of the introducer sheath. For example, the introducer sheath may split along all or a portion of the geometric pattern 3232 after expanding past a predetermined limit. Figure 18 illustrated is a cross section view of another tubular portion of an introducer sheath. This tubular portion 3300 can be used with the introducer sheath 3100 (Figure 15) and function to expand/contract or deform/reform to enable withdrawal of a medical device that may have enlarged in diameter during use. The tubular portion 3300 has a similar configuration to that of tubular portion 3200, and as such the description related to tubular portion 3200 also applies to tubular portion 3300. As with tubular portion 3200, the tubular portion 3300 includes at least one elastic portion 3302 and at least one sheath portion 3304. The elastic portion 3302 and the sheath portion 3304 are mechanically coupled and/or bonded together to provide additional strength to the connection or coupling between the elastic portion 3302 and the sheath portion 3304. For instance, in addition to or instead of a thermal or chemical bond between the elastic portion 3302 and the sheath portion 3304, a mechanical connection is made between the portions 3302 and 3304 to maintain the coupling or attachment of the elastic portion 3302 and the sheath portion 3304.

In the illustrated configuration of Figure 18, the mechanical coupling or connection is facilitated by way of at least one interlocking feature 3306 that cooperates and mechanically engages with a corresponding recess or receiving portion of the sheath portion 3304. Each interlocking feature 3306 can include at least one extension 3308, which extends from the main body of the elastic portion 3302, and at least on protrusion 3310 extending from an end of the extension 3308. With the at least one protrusion 3310 extending from and being generally transverse to the extension 3310, the at least one protrusion 3310 aids with preventing detachment of the elastic portion 3302 from the sheath portion 3304 as the tubular portion 3300 extends/contract or deforms/reforms. Although reference is made to the at least one protrusion 3310 extending transverse to the at least one extension 3308, one skilled in the art will appreciate that the at least one protrusion 3310 can extend from the at least one extension 3308 are other angular orientations while still being capable of preventing detachment. The at least one interlocking feature 3306 illustrated in Figure 18 can extend from a proximal end to a distal end of the tubular portion 3300 and/or the introducer sheath. It will be understood, however, that the at least one interlocking feature 3306 can extend only part way from the distal end toward the proximal end, from the proximal end to the distal end, or at any location along the length of the tubular portion 3300. Similarly, although the interlocking feature 3306 is illustrated as extending from the elastic portion 3302 toward the sheath portion 3304, it will be understood that the corresponding recess or receiving portion of the sheath portion 3304 can also be considered an interlocking feature. Further, the elastic portion 3302 can be configured with the corresponding recess or receiving portion, while the sheath portion 3304 includes the at least one extension 3308 and/or the at least one protrusion 3310. The interlocking feature 3306 of the tubular portion 3300 of Figure 18 can be formed during the manufacturing process of the introducer sheath. For instance, the interlocking feature 3306, with the corresponding recess or receiving portion, can be formed during injection molding or during a co-extrusion process of the tubular portion 3300 and/or the introducer sheath. Alternatively, the interlocking feature 3306 can be formed during manufacture of the elastic portion, such as by injection molding or a co- extrusion process, with the elastic portion being subsequently bonded or coupled to the sheath portion, or vice versa, through thermal bonding, chemical bonding, or other known technique to bond similar or dissimilar medical grade materials. Turning now to Figure 19, illustrated is a cross section view of another tubular portion of an introducer sheath. This tubular portion 3400 can be used with the introducer sheath 3100 (Figure 15) and function to expand/contract or deform/reform to enable withdrawal of a medical device that may have enlarged in diameter during use. Figure 19 illustrates a cross section of the tubular portion 3400 of the introducer sheath as it moves from a first, normal, or unstressed position to a second, expanded or stressed position of the tubular portion 3400. In the first position, again identified by reference letter A, the tubular portion 3400 is in a contracted or relaxed state. The tubular portion 3400 is similar to the tubular portion 3104 (Figure 15), but further includes a plurality of lumens 3420 disposed at least partially in a wall 3422 defined by an outer wall 3408 and an inner wall 3410 of the tubular portion 3400. The region of the tubular portion 3400 containing the plurality of lumens 3422 has a smaller wall thickness than the remainder of the tubular portion 3400. These regions of smaller wall thickness function as elastic portions 3402 of the tubular portion 3400, while those regions of the wall 3422 having no lumens 3422 function as the sheath portion 3404. Stated another way, the inclusion of the plurality of lumens 3422 provides elasticity, expandability, or deformability to the tubular member 3400 at the elastic portions 3402. The number of lumens 3422 in the tubular portion 3400 can vary based upon the degree of flexibility desired for the tubular portion 3400. Further the particular size, cross sectional shape, and/or ratio of lumen cross-sectional area to area of the wall can be varied to obtain different column strength, stiffness, kink resistance, elasticity, deformability, or other desirable mechanical properties or characteristics of the tubular member 3400. In the expanded position, identified by reference letter B, the at least one lumen 3422 enables the relatively thinner wall portions of the tubular member 3400 to stretch, thereby increasing the cross sectional area or shape of the tubular portion 3400. After expansion, the tubular portion 3400 can return to the first position. Generally, by forming the tubular portion as a composite member using materials having the desired elastic properties, whether or not the tubular portion includes at least one lumen to increase the elasticity, expandability, or deformability of the tubular portion, mechanical properties of the tubular portion may be adjusted as desired. For example, if it is desirable to produce a sheath that is expandable during use, an elastomeric material can be selected along with another material having lower elastic properties. Forming a sheath using these materials, particularly in the tubular portion, provides the sheath with the ability to expand when subject to an applied force. As discussed herein, the configuration of the two or more materials in the sheath can vary and may depend on use. For example, one of the materials may be selected to stiffen the overall tubular portion, prevent kinking in the tubular portion, and the like while the other material is selected based on an elastic property. The bond between the first and second materials can be adjusted to facilitate expansion of the sheath at an appropriate time or for other reasons, m addition, the use of a geometric pattern can also be combined with the expandability of the sheath. The geometric pattern formed on the inner wall may be used to assist in splitting the sheath during use at an appropriate time, such as when the diameter exceeds a predetermined limit during expansion of the tubular member. As described above, two or more materials may be utilized to form the sheath in accordance with the present invention. For example, a different material maybe utilized to form the hub portion and one or more materials may be utilized to form the tubular portion of the sheath. Again, the selection of materials may depend on the end use of the sheath, properties of medical devices used with the sheath, and the like or any combination thereof. Although the present invention has been shown and described in accordance with specific embodiments these should not be considered limiting in any manner. For example, multiple materials may be utilized to form a unitary sheath in accordance with the present invention, wherein multiple injection molding processes are performed simultaneously or in stages to form the unitary sheath in accordance with the present invention.

Embodiments of the introducer sheath described herein can be used in various medical procedures. In one example, a medical procedure often begins by introducing a sheath into body lumen, such as a patient's vasculature. After the sheath is properly introduced, a first medical device can be introduced through the sheath. During introduction of the first medical device, the sheath or at least the tubular portion of the sheath may expand to accommodate a size of the first medical device. After the first medical device has been introduced, the medical procedure may be performed. During this procedure, in one example, the size of the first medical device may change. During withdrawal of the first medical device, at least the tubular portion of the sheath can expands or deform accommodate the increased size of the first medical device. The expansion or change in cross sectional area can occur at different locations of the sheath or of the tubular portion as the first medical device is withdrawn. After the first medical device is withdrawn, a second medical device, such as a vessel closure device, stent delivery device, or other medical device, can be introduced through the sheath. This newly inserted medical device can be used without prior insertion of another introducer sheath. In the case of the vessel closure device, the vessel closure device can be placed in the desired location relative to the vessel wall and the introducer sheath removed before, during, or part of the vessel sealing process.

The above-described process is illustrated in more detailed with reference to Figures 20A-20D. Figures 20A-20D illustrate an example of one configuration of an expandable introducer sheath during use in a medical procedure. A sheath 3600, which can be any of the introducer sheaths previously described with respect to Figures 15-19, can be inserted into a vessel or vasculature 3610 of a patient, hi this example, the tubular portion 3604 of the sheath 3600 is formed of a first elastomeric material 3606 and a second material 3608. With the introducer sheath 3600 in place one or more medical devices or instruments can be passed therethrough, such as through the lumens of the hub portion 3602 and the tubular portion 3604, to gain access to the vasculature 3610 and more particular to a treatment site. In one configuration, and with reference to Figure 2OB, a medical device, such as, but not limited to, a dilation balloon or an intra-aortic balloon pump, identified by reference numeral 3620, can be passed through the hub portion 3602. During use of the medical device 3620, the outside diameter of the medical device 3420 increases in size from when it was originally introduced into the vasculature 3610 by way of the sheath 3600. The structure and function of the tubular portion 3604 and/or the introducer sheath 3600 can, however, accommodate such a change and eliminates the need to remove the introducer sheath 3600 with the medical device 3620. With continued reference to Figure 2OB, once the medical procedure is complete, the medical device 3620 can be withdrawn until the medical device 3620 contacts the distal end of the introducer sheath 3600 and/or the entry portion 3628 that facilitates entry of the medical device 3620 back through the sheath 3616. As the medical device 3620 is withdrawn, its size introduces a force that causes the tubular portion 3604 to expand as the first elastomeric material 3606 flexes, expands, or deforms accommodate the pump 3604, as illustrated in Figure 2OC.

As the medical device 3620 is withdrawn through the tubular portion 3604, regions of the first elastomeric material 3606 expand, such as in region 3612, such that a cross sectional area of the lumen of the sheath 3600 has increased at least at this location. The medical device 3620 can therefore be withdrawn without splitting the sheath 3600 or without having to remove the sheath 3600 from the vasculature 3610 during removal of the medical device 3620.

After the medical device 3620 is withdrawn, Figure 2OD illustrates that another medical device 3422, such as a vessel closure device, a stent delivery device, or other medical device, can be introduced into the vasculature 3620 via the sheath 3600. Without the expansion capability enabled by the embodiments disclosed herein, the sheath would have to be removed earlier than desired, which could preclude use of other medical devices, such as, but not limited to, the vessel closure device.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. AIl changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Although the present invention has been described with regard to specific designs and materials, it shall not be considered limiting in any manner. For example, materials not described herein may be utilized as well as methods and processes.

Although the present invention has been described with regard to specific designs and materials, it shall not be considered limiting in any manner. For example, materials not described herein may be utilized as well as methods and processes. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. AU changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

What is claimed is: 1. An introducer sheath, comprising: a hub having a proximal end and a distal end and a lumen extending therebetween; an elongated tubular member having a proximal end and a distal end; and a retaining member, the retaining member sized to be received within the lumen of the hub and being further configured to retain the proximal end of the tubular member within the lumen of the hub.

2. The introducer sheath of claim 1, further including a strain relief portion adjacent a distal end of the hub and adjacent a proximal end of the tubular portion.

3. The introducer sheath of claim 1, further comprising a flexible valve member disposed in a proximal end of the hub.

4. The introducer sheath of claim 3, wherein the valve member is additionally in communication with the retaining member.

5. The introducer sheath of claim 3, further comprising a cap disposed adjacent the flexible valve member and coupled to the proximal end of the hub.

6. The introducer sheath of claim 5, wherein the valve member has an opening formed therein; and the cap is configured such that upon being disposed over the valve member, the cap provides a compressive force to the valve member which causes the opening in the valve member to be squeezed, thereby increasing the strength of the seal without reducing access to the lumen of the hub.

7. The introducer sheath of claim 1, further comprising an aperture extending through a wall of the hub.

8. The introducer sheath of claim 1, wherein the elongate tubular member includes an outer wall and an inner wall thereby defining a thickness, and a pattern fanned within the inner wall.

9. An introducer sheath, comprising: a hub having a proximal end and a distal end and a lumen extending therebetween; an elongated tubular member having a proximal end and a distal end, the proximal end of the tubular member having a flared portion; and a retaining member having a proximal end and a distal end and being configured to be received within the lumen of the hub, the distal end of the retaining member being configured to contact the flared portion of the tubular member such that the proximal end of the tubular member is retained within the lumen of the hub upon the retaining member being receive in the hub.

10. The introducer sheath of claim 9, wherein the distal end of the retaining member, the hub, and the proximal end of the tubular member form a fluid seal.

11. The introducer sheath of claim 9, wherein: the hub further comprises a first locking feature formed in the lumen thereof; the retaining member further comprises a second locking feature formed in the outside surface thereof, the second locking feature of the resilient member resiliency engages the first locking feature upon the retaining member being disposed in the lumen of the hub.

12. The introducer sheath of claim 9, further comprising a flexible valve member disposed in the proximal end of the hub.

13. The introducer sheath of claim 9, further comprising a cap removably disposed in the proximal end of the hub.

14. The introducer sheath of claim 9, further comprising a dilator configured to removably cooperate with the cap.

15. The introducer sheath of claim 14, wherein the dilator comprises a handle having a resilient locking feature configured to be removably disposed in the cap.

16. The introducer sheath of claim 15, wherein the locking feature of the handle comprises at least one resilient member configured to be removably disposed in the cap.

17. The introducer sheath of claim 16, wherein: the cap has an aperture formed therein; and the at least one resilient member is configured to be resiliently disposed in the aperture of the cap.

18. The introducer sheath of claim 9, further comprising a strain relief portion adjacent a distal end of the hub.

19. An introducer sheath, comprising: a hub having a proximal end and a distal end with a lumen extending therebetween, the lumen of the hub having a groove formed therein; an elongated tubular member having a proximal end and a distal end, the proximal end of the tubular portion having flared portion; and a retaining member having a proximal end and a distal end, the distal end of the retaining member being configured to be received in the groove formed in the lumen of the hub, the distal end of the retaining member contacting the flared portion of the tubular member when distal end of the retaining member is disposed in the groove portion such that the tubular member is retained within the lumen of the hub in a sealing engagement.

20. The introducer sheath of claim 19, wherein the distal end of the retaining member, the flared portion of the tubular member and the hub form a seal.

21. The introducer sheath of claim 19, further comprising a cap removably disposed in the proximal end of the hub, the cap having an aperture formed therein.

22. The introducer sheath of claim 19, further comprising a dilator configured to removably cooperate with the cap, the dilator having a resilient locking feature configured to be removably disposed in the aperture in the cap.

23. An introducer sheath, comprising: a hub having a proximal end and a distal end and a lumen extending therebetween; an elongated tubular member having a proximal end and a distal end; and means for retaining the tubular member in the hub in sealing engagement, the retaining means comprising a flared portion on the proximal end of the tubular member.

24. The introducer sheath of claim 23, further comprising a retaining member having a proximal end and a distal end and being configured to be received within the lumen of the hub.

25. The introducer sheath of claim 24, wherein said retaining means further comprises: a shoulder portion formed in the hub; and the distal end of the retaining member configured cooperate with the shoulder portion formed in said hub.

26. The introducer sheath of claim 25, wherein the shoulder portion in the hub has a groove formed therein configured to cooperate with the distal end of the retaining member.

27. The introducer sheath of claim 26, wherein the distal end of the retaining member is configured to be received in the groove formed in the shoulder portion of the hub.

28. The introducer sheath of claim 24, wherein upon the retaining member being received in the lumen of the hub, the distal end of the retaining member engages the flared portion of the proximal end of the tubular member such that the tubular member is retained within the lumen of the hub in a sealing engagement with the hub and the retaining member.

29. The introducer sheath of claim 23, further comprising: a first locking feature formed in the lumen of the hub; a second locking feature formed in the outside surface of the retaining member configured to cooperate with the first locking feature formed in the lumen of the hub.

30. An introducer sheath comprising individual components that are configured so as to be assembled using only resilient connections, the introducer sheath comprises: a hub having a proximal end and a distal end and a lumen extending therebetween; an elongated tubular member having a proximal end and a distal end; a retaining member configured to be received within the lumen of the hub and to retain the proximal end of the tubular member within the lumen of the hub; a flexible valve disposed in the proximal end of the hub; and a cap removably disposed in the proximal end of the hub.