Expandable sheath for introducing an intravascular delivery device into the body - Patent Application 20070122997

Abstract

Embodiments of an expandable sheath can be used with a catheter assembly to introduce a prosthetic device, such as a heart valve, into a patient. Such embodiments can minimize trauma to the blood vessel by allowing a portion of the introducer sheath to temporarily expand to accommodate a delivery apparatus and then return to its original diameter once the prosthetic device has passed. Some embodiments can include a sheath having a variable diameter inner liner and an outer layer wound in a helical, slidable configuration. The disclosed sheath is configured to expand from a predetermined rest diameter dr to an expanded diameter de during application of a radially outward force by passage of a medical device through the sheath.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 62 / 982,253, filed February 27, 2020, and U.S. Provisional Application No. 63 / 109,171, filed November 3, 2020, the contents of which are incorporated herein by reference in their entireties.

[0002] The present application relates to aspects of a sheath for use with catheter-based techniques to repair and / or replace heart valves and to deliver prosthetic devices, such as prosthetic valves, to the heart via a patient's vasculature. [Background technology]

[0003] Intravascular delivery catheter assemblies are used to implant prosthetic devices, such as artificial valves, in locations within the body that are not easily accessible by surgery or where it is desirable to access them without invasive surgery. For example, prosthetic aortic, mitral, tricuspid, and / or pulmonary valves can be delivered to treatment sites using minimally invasive surgical techniques.

[0004] An introducer sheath may be used to safely introduce a delivery device into a patient's vasculature (e.g., the femoral artery). The introducer sheath generally has an elongated sleeve that is inserted into the vasculature and a housing that includes one or more sealing valves that allow the delivery device to be placed in fluid communication with the vasculature while minimizing blood loss. Conventional introducer sheaths typically require a tubular loader to be inserted through a seal in the housing to provide an unobstructed path through the housing for a valve attached to the balloon catheter. Because the conventional loader extends from the proximal end of the introducer sheath, it reduces the available working length of the delivery device that can be inserted through the sheath and into the body.

[0005] Conventional methods of accessing a blood vessel, such as the femoral artery, prior to introducing a delivery system involve dilating the vessel using multiple dilators or sheaths of gradually increasing diameter. This repeated insertion and vessel dilation can increase the amount of time the procedure takes and the risk of injury to the vessel.

[0006] Radially expanding intravascular sheaths have been disclosed, and such sheaths tend to have complex mechanisms, such as ratcheting mechanisms, that maintain the shaft or sheath in an expanded configuration when a device having a diameter larger than the original diameter of the sheath is introduced.

[0007] However, delivery and / or removal of prosthetic devices and other materials to and from patients still poses significant risks to the patient. Additionally, access to blood vessels remains a challenge because the relatively large profile of delivery systems can cause longitudinal and radial tearing of the vessel during insertion. Delivery systems can also displace calcified plaque within the vessel, further posing a risk of blood clots caused by the detached plaque. Summary of the Invention [Problem to be solved by the invention]

[0008] Thus, there remains a need in the art for improved introducer sheaths for endovascular systems used to implant valves and other prosthetic devices. [Means for solving the problem]

[0009] Embodiments of the presently disclosed expandable sheath can minimize trauma to the vessel by allowing a portion of the introducer sheath to temporarily expand to accommodate a delivery system and then return to its original diameter once the delivery system has passed. Some embodiments can include a sheath with a smaller profile than that of prior art introducer sheaths. Additionally, certain embodiments can shorten the length of time required for the procedure and reduce the risk of tearing the vessel longitudinally or radially or displacing plaque because only one sheath is required rather than multiple sheaths of different sizes. Embodiments of the presently disclosed expandable sheath can require only a single vessel insertion rather than multiple insertions for vessel expansion.

[0010] In one aspect, a sheath for introducing a prosthetic device is disclosed that includes an inner liner and an outer layer, wherein at least a portion of the sheath can be designed or configured to locally expand from a first diameter (rest diameter) to a second diameter (expanded diameter) when a prosthetic device is pushed through the lumen of the sheath, and to at least partially return to the first diameter after the prosthetic device has passed.

[0011] Also disclosed herein are embodiments directed to a sheath for delivering a medical device, the sheath having a proximal end and a distal end, the sheath comprising a variable diameter inner liner comprising a sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet being wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a cylindrical lumen having a longitudinal axis. and an outer layer having an inner surface and an outer surface, the outer layer extending around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the inner liner, the outer layer comprising a braid or coil and a layer of an elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface, the variable diameter inner liner being configured to have a predetermined rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through a lumen of the inner liner. r to expansion diameter d e The system is configured to extend to

[0012] Also disclosed herein are embodiments that include methods of making a sheath having a proximal end and a distal end. In certain embodiments, a method of making such a sheath includes forming a variable diameter inner liner by winding a sheet having a first edge and a second edge, the sheet being defined by inner and outer surfaces in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming an overlap, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, and the inner surface of the sheet defining a cylindrical lumen having a longitudinal axis; forming an outer layer having a side surface extending around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the inner liner, the outer layer comprising a braid or coil and a layer of an elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface, wherein the variable diameter inner liner is configured to have a predetermined rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to expansion diameter d e The system is configured to extend to

[0013] Further, additional or alternative embodiments of a sheath for delivering a medical device are disclosed, the sheath having a proximal end and a distal end, the sheath comprising a variable diameter inner liner comprising a sheet, the sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a cylindrical lumen having a longitudinal axis. a variable diameter inner liner; and an outer layer having an inner surface and an outer surface, the outer layer extending around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the inner liner, the outer layer comprising at least one layer of a first elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface, the variable diameter inner liner being configured to have a predetermined rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through a lumen of the inner liner. r to expansion diameter d e The system is configured to extend to

[0014] Additionally, an embodiment is disclosed directed to a method of making a sheath having a proximal end and a distal end, the method including the steps of forming a variable diameter inner liner by winding a sheet having a first edge and a second edge, the sheet defined by inner and outer surfaces in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming an overlapping portion, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, and the inner surface of the sheet defining a cylindrical lumen having a longitudinal axis. and forming an outer layer having an inner surface and an outer surface, the outer layer extending around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the inner liner, the outer layer comprising at least one layer of a first elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface, wherein the variable diameter inner liner is configured to have a predetermined rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through a lumen of the inner liner. r to expansion diameter d e The system is configured to extend to

[0015] Further disclosed herein are embodiments directed to a sheath for delivering a medical device, the sheath having a proximal end and a distal end, the sheath having a) a first rest diameter d r and the second expansion diameter d ean inner liner defining a lumen having a first surface and an opposing second surface, the lumen configured to receive and pass a medical device, the inner liner comprising a sheet having a first portion having a first surface and an opposing second surface, a first end of the first portion divided into a first segment having the first surface and the opposing second surface and a third segment having the first surface and the opposing second surface, the second end of the first portion extending into the second segment having the first surface and the opposing second surface, the sheet wound into a spiral configuration such that at least a portion of the first surface of the second segment is adjacent to at least a portion of the second surface of the first segment. at least a portion of the first surface of the third segment overlaps with at least a portion of the second surface of the second segment, at least a portion of the first surface of the third segment overlaps with at least a portion of the second surface of the first segment, the first surface of the first portion extends into the first surfaces of the first segment, the second segment, and the third segment, and the second surface of the first portion extends into the second surfaces of the second and third segments, each segment configured to slidably move along one another when the medical device is passed through the lumen, and the sheet comprises: a) an inner liner comprising a polymer layer; and b) an outer layer.

[0016] Further disclosed herein are embodiments directed to a sheath for delivering a medical device, the sheath having a proximal end and a distal end, the sheath comprising a variable diameter inner liner comprising a sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet being wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet. the sheet is slidable along at least a portion of a surface thereof, an inner surface of the sheet defining a lumen of the sheath having a longitudinal axis, the sheet comprising a variable diameter inner liner comprising a polymer layer and an outer layer having a predetermined thickness and having an inner surface and an outer surface, the variable diameter inner liner being configured to have a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0017] In one aspect, disclosed herein is a sheath for delivering a medical device, the sheath having a proximal end and a distal end, the sheath comprising a variable diameter inner liner comprising a sheet comprising a polymeric layer comprising a composite material, the composite material comprising a polyolefin present in an amount from greater than 0 wt % to less than 100 wt %, based on a total weight of the composite, and a lubricious filler present in an amount from about 5 wt % to about 20 wt % of the total weight of the composite, the sheet being wound in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, and a first longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet. and the second longitudinal edge is slidable along at least a portion of an outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and an outer layer having a predetermined thickness and having an inner surface and an outer surface, the inner surface of the outer layer being disposed on the outer surface of the spiral configuration of the inner liner, wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0018] In one aspect, disclosed herein is a sheath for delivering a medical device, the sheath having a proximal end and a distal end, the sheath comprising a variable diameter inner liner comprising a sheet wound into a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, a first longitudinal edge of the sheet being slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and an outer layer having an inner surface and an outer surface, a lubricious liner disposed between the outer surface of the inner liner and the inner surface of the outer layer, wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0019] In a further aspect, a sheath for delivering a medical device is disclosed, the sheath having a proximal end and a distal end, the sheath comprising: a variable diameter inner liner comprising a sheet wound in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, a first longitudinal edge of the sheet being slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and a tie layer disposed on the inner surface of the sheet and adapted to be disposed on at least an innermost surface of the lumen between the overlapping portions when the sheet is in the spiral configuration. and / or a tie layer disposed on an outer surface of the sheet and adapted to be disposed on at least the outermost surface of the inner liner between overlapping portions when the sheet is in a spiral configuration, wherein at least one lubricious liner is disposed on the tie layer; and an outer layer having a predetermined thickness and having an inner surface and an outer surface, wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through a lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0020] Further disclosed herein are embodiments directed to a sheath for delivering a medical device, the sheath having a proximal end and a distal end, the sheath comprising: a variable diameter inner liner comprising a sheet wound into a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, a first longitudinal edge of the sheet being slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and an elongated tube forming an outer layer of the sheath, the outer layer of the sheath being positioned at least at the proximal end of the sheath, extending along at least a portion of a length of the sheath, the elongated tube having an inner surface and an outer surface, the elongated tube comprising: a) a first composite and b) a second polymer layer comprising a polyurethane, wherein the first composite composition comprises: i) greater than 0 wt % to less than 100 wt % of a polymer, based on the total weight of the first composite composition, the polymer comprising a polyether block amide, a polyurethane, or a combination thereof; ii) less than about 65% of an inorganic filler, based on the total weight of the first composite composition; and iii) up to about 20% of a solid lubricant filler, based on the total weight of the first composite composition; and b) a second polymer layer comprising polyurethane, wherein the elongated tubing is bump tubing and is a coextrusion of the first polymer and the second polymer; and wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0021] In yet another aspect, a sheath for delivering a medical device is disclosed, the sheath having a proximal end and a distal end, the sheath comprising: a variable diameter inner liner comprising a sheet wound in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, a first longitudinal edge of the sheet being slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and an elongated tube forming an outer layer of the sheath, the outer layer of the sheath being positioned at least at the proximal end of the sheath, extending along at least a portion of a length of the sheath, the elongated tube having an inner surface and an outer surface, the elongated tube comprising: a) a first polymer layer comprising a first composite composition; the first composite composition comprises: i) a first polymer layer comprising, based on the total weight of the first composite composition, greater than 0 wt % to less than 100 wt % of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof; ii) less than about 65% of an inorganic filler, based on the total weight of the first composite composition; and iii) up to about 20% of a solid lubricant filler, based on the total weight of the first composite composition; and b) a second polymer layer comprising polyurethane, the second polymer layer at least partially overlapping the first polymer layer, the first polymer layer being disposed at a proximal end of the sheath and having a length shorter than a length of the second polymer layer; and the variable diameter inner liner is configured to have a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0022] Further disclosed herein is an embodiment of a sheath for delivering a medical device, the sheath having a proximal end and a distal end, the sheath comprising a variable diameter inner liner comprising a sheet wound into a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, a first longitudinal edge of the sheet being slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and an outer layer having a predetermined thickness and having an inner surface and an outer surface, at least a portion of the innermost surface of the outer layer being bonded to at least a portion of the outermost surface of the inner liner, the variable diameter inner liner being configured to have a first rest diameter d by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0023] In some embodiments, a sheath for delivering a medical device is disclosed, the sheath having a proximal end and a distal end, the sheath comprising: a variable diameter inner liner comprising a sheet wound into a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, a first longitudinal edge of the sheet being slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and a variable diameter inner liner having a predetermined thickness and an inner the reinforcing jacket includes an outer layer having a surface and an outer surface, and a reinforcing jacket having a proximal end and a distal end, the reinforcing jacket being disposed on at least a portion of the outer surface of the outer layer, the reinforcing jacket including an elastomer and a reinforcing element, the distal end of the reinforcing jacket being substantially seamlessly bonded to at least a portion of the outer surface of the outer layer, and the variable diameter inner liner being configured to have a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through a lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0024] In yet another aspect, a sheath for delivering a medical device is disclosed, the sheath having a proximal end and a distal end, the sheath comprising: a variable diameter inner liner comprising a sheet wound in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, a first longitudinal edge of the sheet being slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; an outer layer having a predetermined thickness, the outer layer having an inner surface and an outer surface, the outer layer extending from the proximal end of the sheath to the distal end of the sheath; and a ballooning guard having a proximal end and a distal end and disposed on at least a portion of the outer layer. and a ballooning guard configured to remain outside of a blood vessel of the subject and maintain hemostasis, wherein a proximal end of the ballooning guard is connected to a proximal-most portion of the outer layer and / or a hub of the sheath, and a distal end of the ballooning guard radially surrounds at least a portion of the outer layer, the distal end being unbonded to the outer layer, and the ballooning guard configured to adjust a length of the guard as a function of insertion depth of the inner liner and outer layer of the sheath relative to the blood vessel of the subject.

[0025] Yet another aspect is disclosed directed to a method of making a sheath having a proximal end and a distal end, the method comprising the steps of: a) forming an inner liner; i) providing a double lumen tubing with two channels extruded in a single tube configuration, the double lumens comprising at least one polymer layer, a first channel having an inner surface and an outer surface, and a second channel having an inner surface and an outer surface, the second channel being disposed within the first channel such that at least a portion of a perimeter of the first channel and at least a portion of a perimeter of the second channel have at least one shared inner surface and at least one shared outer surface, the outer surface of the first channel defining an outer surface of the double lumen tubing; and ii) longitudinally cutting the first channel at a portion of a perimeter of the first channel that is not shared with the perimeter of the second channel to form a first sheet having a first edge and a second edge, the second channel being disposed within at least a portion of the perimeter of the first channel. and iii) longitudinally cutting the second channel at a portion of the periphery of the second channel abutting the surface shared with the first sheet to form a second sheet having a first edge and a second edge, the second edge being defined by the portion of the surface shared with the first sheet. and iv) winding the first sheet and the second sheet into a spiral configuration, whereby I) a shared surface between the second sheet and the first sheet forms a first portion of an inner liner having a first surface and an opposite second surface, II) at least a portion of the second sheet forms a first segment of an inner liner having a first surface and an opposite second surface, and III) a portion of the first sheet adjacent the second end of the second sheet and extending to the first end of the first sheet isIV) a portion of the first sheet adjacent the second end of the second sheet and extending to the second end of the first sheet forms a third segment of the inner liner having a first surface and an opposite second surface, in a spiral configuration, at least a portion of the first surface of the second segment overlaps with at least a portion of the second surface of the first segment, and at least a portion of the first surface of the third segment overlaps with at least a portion of the second surface of the second segment, and b) forming an inner liner by: a) forming an inner liner by: a) forming an inner liner by: a) forming an inner liner by: b) forming an inner liner by: a) forming an inner liner by: b) forming an inner liner by: c) forming an inner liner by: c) forming an inner liner by: a) forming an inner liner by: b) forming an inner liner by: c) forming an inner liner by: a) forming an inner liner by: b) forming an inner liner by: c) forming an inner liner by: r to the second expansion diameter d e and the first rest diameter d r and configured to return to substantially the same diameter as the diameter of the first hole.

[0026] Further disclosed herein is a method of making a sheath having a proximal end and a distal end, the method comprising the steps of: a) forming a variable diameter inner liner, i) providing an elongated single-lumen tubing comprising at least one polymer layer; ii) longitudinally cutting at least a portion of the circumference of the elongated single-lumen tubing to form a sheet having a first longitudinal edge and an opposite second longitudinal edge and having an inner surface and an outer surface; and iii) winding the sheet into a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming the variable diameter inner liner. a) forming a variable diameter inner liner by: b) forming a portion of the sheet, wherein a first edge of the sheet is slidable along at least a portion of an inner surface of the sheet and a second edge is slidable along at least a portion of an outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and c) disposing an outer layer over at least a portion of the outer layer of the inner liner, such that during application of a radially outward force by passage of a medical device through the lumen of the inner liner, the first longitudinal edge of the sheet is slidable along at least a portion of the inner surface and the second longitudinal edge of the sheet is slidable along at least a portion of the outer surface, thereby forming a variable diameter inner liner. r to expansion diameter d e The method includes forming a sheath configured to expand into a distal end of the catheter.

[0027] In some embodiments, a method of forming a sheath is disclosed, the method comprising the steps of: a) positioning elongate tubing over a mandrel; b) disposing a quantity of lubricant on an outer surface of the elongate tubing in a predetermined pattern; c) curing the lubricant; d) cutting the elongate tubing along a length of the tubing at a portion of the circumference of the tubing to form a sheet having an outer surface and an inner surface and having a first longitudinal edge and a second longitudinal edge, wherein the inner surface forms the sheath lumen and at least a portion of the outer surface includes the lubricant disposed in the predetermined pattern; and e) spiraling the sheet such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet. f) winding the sheet so that the first edge of the sheet is slidable along at least a portion of the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, to form an overlapping portion, wherein the first edge of the sheet is slidable along at least a portion of the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet; and f) disposing an outer layer having an inner surface and an outer surface on the outer surface of the inner liner such that a lubricant is disposed between at least a portion of the inner surface of the outer layer and at least a portion of the outer surface of the inner layer to form a sheath, wherein the sheath is configured to have a predetermined rest diameter d by sliding the first longitudinal edge of the sheet along at least a portion of the inner surface and sliding the second longitudinal edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to expansion diameter d e and configured to expand the

[0028] In another aspect, a method of making a sheath having a proximal end and a distal end is disclosed, the method comprising the steps of: a) extruding a tubular body to form an elongated tubing comprising a composite material, the composite material comprising a polyolefin present in an amount from greater than 0 wt % to less than 100 wt %, based on the total weight of the composite, and a lubricious filler present in an amount from about 5 wt % to about 20 wt % of the total weight of the composite; b) cutting the elongated tubing around at least a portion of the circumference along the length of the elongated tubing to form a sheet; and c) forming an inner liner by winding the sheet in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, a first longitudinal edge slidable along at least a portion of an inner surface of the sheet and a second longitudinal edge slidable along at least a portion of an outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and d) positioning an outer layer having a predetermined thickness and having an inner surface and an outer surface, the inner surface of the outer layer being disposed on the outer surface of the spiral configuration of the inner liner, wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0029] In yet another aspect, a method of making a sheath having a proximal end and a distal end is disclosed, the method comprising the steps of: a) co-extruding a polymer layer and a tie layer to form an elongated tubing; b) positioning at least one lubricious liner on an outer surface of an inner liner; c) cutting the elongated tubing around at least a portion of the circumference along the length of the elongated tubing to form a sheet; and d) forming the inner liner by winding the sheet in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, wherein a first longitudinal edge of the sheet is positioned adjacent to the inner surface of the sheet. and the second longitudinal edge is slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and e) positioning an outer layer having a predetermined thickness and having an inner surface and an outer surface on the at least one lubricious liner to form a sheath, wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to the second expansion diameter d e The system is configured to extend to

[0030] In yet another aspect, a method of making a sheath having a proximal end and a distal end is disclosed, the method comprising the steps of: a) co-extruding a polymer layer and a tie layer to form an elongated tubing; b) positioning at least one lubricious liner on the tie layer; c) cutting the elongated tubing around at least a portion of the circumference along the length of the elongated tubing to form a sheet; and d) forming an inner liner by winding the sheet in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, wherein a first longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet. a first edge of the sheet slidable along at least a portion of an outer surface of the sheath, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis, such that when the sheet is in a spiral configuration, a tie layer is disposed on at least the inner surface of the lumen between the overlapping portions, and / or when the sheet is in a spiral configuration, a tie layer is disposed on the outermost surface of the inner liner between the overlapping portions; and e) positioning an outer layer having a predetermined thickness and having an inner surface and an outer surface to form a sheath, wherein the variable diameter inner liner is adjustable to a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radial force. r to the second expansion diameter d e The system is configured to extend to

[0031] Additionally or alternatively, a method of making a sheath having a proximal end and a distal end is disclosed, the method comprising: a) co-extruding an elongated bump tubing comprising a first polymer layer and a second polymer layer, wherein i) the first polymer layer comprises a first composite composition comprising from greater than 0% to less than 100% polymer, based on the total weight of the first composite composition, including a polyether block amide, a polyurethane, or a combination thereof, less than about 65% inorganic filler, based on the total weight of the first composite composition, and up to about 20% solid lubricant filler, based on the total weight of the first composite composition; ii) the second polymer layer comprises polyurethane, wherein the first polymer layer defines an inner surface of the tubing and the second polymer layer defines an outer surface of the tubing; and b) co-extruding an elongated bump tubing comprising a first polymer layer and a second polymer layer, wherein i) the first polymer layer comprises a first composite composition comprising from greater than 0% to less than 100% polymer, based on the total weight of the first composite composition, including a polyether block amide, a polyurethane, or a combination thereof, based on the total weight of the first composite composition, less than about 65% inorganic filler, based on the total weight of the first composite composition, and up to about 20% solid lubricant filler, based on the total weight of the first composite composition. forming an inner liner by winding the sheet in a spiral configuration such that a portion overlaps at least a portion of an outer surface of the sheet, wherein a first longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge is slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and c) disposing elongated bump tubing on the sheath such that the elongated bump tubing forms an outer layer of the sheath, the elongated tube being positioned at least at a proximal end of the sheath and extending along at least a portion of the length of the sheath, the elongated bump tubing expanding from an initial diameter d0 in a non-use position to an expanded diameter d in an expanded position as a medical device is passed therethrough. e and the variable diameter inner liner is configured to reversibly expand to a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radial force. r to the second expansion diameter d e The system is configured to extend to

[0032] Further disclosed is a method of making a sheath having a proximal end and a distal end, the method comprising the steps of: a) forming an inner liner by winding a sheet in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, wherein a first longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge is slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and b) disposing a first polymer layer comprising a first composite composition, the first composite composition comprising, based on a total weight of the first composite composition: a first composite composition including from greater than 0% to less than 100% polymer, including a polyether block amide, a polyurethane, or a combination thereof; less than about 65% inorganic filler, based on the total weight of the first composite composition; and up to about 20% solid lubricant filler, based on the total weight of the first composite composition, the first polymer layer being disposed on a proximal portion of the inner liner and having a length of from about 5 cm to about 15 cm; and c) disposing a second polymer layer including polyurethane on the first polymer layer, the second polymer layer extending along the length of the sheath, the first polymer layer and the second polymer layer together expanding from an initial diameter d0 in a non-use position to an expanded diameter d in an expanded position as a medical device is passed therethrough. e and a variable diameter inner liner configured to reversibly expand to a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radial force. r to the second expansion diameter d e The system is configured to extend to

[0033] Alternatively or additionally, a method for making a sheath having a proximal end and a distal end is disclosed, the method comprising the steps of: a) forming an inner liner by winding a sheet in a spiral configuration so that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, wherein a first longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge is slidable along at least a portion of the outer surface of the sheet, and the inner surface of the sheet defines a lumen of the sheath having a longitudinal axis; b) disposing an outer layer on the inner liner to form the sheath; and c) positioning the sheath on a mandrel configured to rotate. d) aligning the mandrel with a laser beam configured to move along the longitudinal axis of the sheath a predetermined distance under conditions effective to form a bond; and e) forming a bond in a predetermined portion of the sheath between at least a portion of an outermost surface of the inner liner and at least a portion of an innermost surface of the outer layer, the predetermined portion being substantially free of lubricant and / or bonding layer, wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radial force. r to the second expansion diameter d e The system is configured to extend to

[0034] Alternatively or additionally, a method of making a sheath having a proximal end and a distal end is disclosed, the method comprising the steps of: a) forming an inner liner by winding a sheet in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, wherein a first longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge is slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; b) disposing an outer layer on the inner liner to form the sheath; c) positioning the sheath over a mandrel configured to rotate; and d) rotating the sheath to compress the sheath to a predetermined diameter. a) inserting a mandrel into a radial compression head bonder including a collapsible opening configured with a plurality of dies, at least one of the plurality of dies being heated to form a bond at a predetermined portion of the sheath; and b) forming a bond at the predetermined portion of the sheath between at least a portion of an outermost surface of the inner liner and at least a portion of an innermost surface of the outer layer, the predetermined portion being substantially free of lubricant and / or bonding layer, wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radial force. r to the second expansion diameter d e The system is configured to extend to

[0035] Additionally or alternatively, a method of making a sheath having a proximal end and a distal end is disclosed, the method comprising the steps of: a) forming an inner liner by winding a sheet in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, wherein a first longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge is slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and b) winding a sheet of the inner liner in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis. c) disposing an outer layer over at least a portion of the outer layer to form a sheath, c) disposing a reinforcing jacket having a proximal end and a distal end over at least a portion of the outer layer, the reinforcing jacket including an elastomer and a reinforcing element; and d) substantially seamlessly bonding the distal end of the reinforcing jacket to at least a portion of the outer layer, wherein the variable diameter inner liner is configured to have a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radial force. r to the second expansion diameter d e The system is configured to extend to

[0036] Additionally or alternatively, a method of making a sheath having a proximal end and a distal end is disclosed, the method comprising the steps of: a) forming an inner liner by winding a sheet in a spiral configuration such that at least a portion of an inner surface of the sheet overlaps at least a portion of an outer surface of the sheet, wherein a first longitudinal edge of the sheet is slidable along at least a portion of the inner surface of the sheet and a second longitudinal edge is slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; b) disposing an outer layer over at least a portion of the inner liner to form the sheath; and c) disposing a ballooning guard over at least a portion of the outer layer, the ballooning guard having a proximal end and a distal end. wherein the ballooning guard is configured to remain outside of the subject's blood vessel and maintain hemostasis; and d) connecting a proximal end of the ballooning guard to a proximal-most portion of the outer layer and / or a hub of the sheath, wherein a distal end of the ballooning guard radially surrounds at least a portion of the outer layer, the distal end being unbonded to the outer layer, wherein the ballooning guard is configured to adjust a length of the guard as a function of an insertion depth of the inner liner and outer layer of the sheath relative to the subject's blood vessel, the variable diameter inner liner adjusting a first rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radial force. r to the second expansion diameter d e The system is configured to extend to

[0037] The above and other features and advantages of the present disclosure will become more apparent from the following detailed description which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is an elevational view of a sheath according to the present disclosure with an endovascular delivery device for implanting a prosthetic valve. [Figure 2A]1A-1C are cross-sectional views of an embodiment of a sheath for introducing a prosthetic device into a patient. [Figure 2B] 1A-1C are cross-sectional views of an embodiment of a sheath for introducing a prosthetic device into a patient. [Figure 2C] FIG. 1 is a perspective view of one component of such a sheath. [Figure 3A] 10A-10C are elevational views of an embodiment of a sheath according to the present disclosure having varying rest dr diameters. [Figure 3B] FIG. 10 is an elevational view of an embodiment of a sheath according to the present disclosure having a uniform rest dr diameter. [Figure 3C] 10A-10C are elevational views of an embodiment of a sheath according to the present disclosure having varying rest dr diameters. [Figure 4A] 1 is a partial elevational view of an exemplary embodiment of a braided structure having a PIC according to the present disclosure. FIG. [Figure 4B] 1 is a partial elevational view of an exemplary embodiment of a braided structure having a PIC according to the present disclosure. FIG. [Figure 4C] 1 is a partial elevational view of an exemplary embodiment of a braided structure having a PIC according to the present disclosure. FIG. [Figure 4D] 1 is a partial elevational view of an exemplary embodiment of a braided structure having a PIC according to the present disclosure. FIG. [Figure 5A] FIG. 1 is a cross-sectional view of one embodiment of an exemplary inner liner, showing the unexpanded configuration. [Figure 5B] FIG. 1 is a cross-sectional view of one embodiment of an exemplary inner liner, showing the expanded configuration. [Figure 6A] 1A-1C are cross-sectional views of exemplary sheath embodiments. [Figure 6B] 1A-1C are cross-sectional views of exemplary sheath embodiments. [Figure 6C] 1A-1C are cross-sectional views of exemplary sheath embodiments. [Figure 6D] 1A-1C are cross-sectional views of exemplary sheath embodiments. [Figure 6E] 1A-1C are cross-sectional views of exemplary sheath embodiments. [Figure 6F] 1 is a perspective view of an exemplary sheath embodiment. [Figure 6G]1 is a perspective view of an exemplary sheath embodiment. [Figure 6H] 1A-1C are cross-sectional views of exemplary sheath embodiments. [Figure 6I] 1 is a perspective view of an exemplary sheath embodiment. [Figure 7] FIG. 1 is a block diagram of one aspect of a method of making a sheath according to the present disclosure. [Figure 8] FIG. 10 is a block diagram of another embodiment of a method of making a sheath according to the present disclosure. [Figure 9A] 9A-9C are cross-sectional views of the method steps of the method shown in FIGS. [Figure 9B] 9A-9C are side views of the method steps of the method shown in FIGS. [Figure 9C] 9A-9C are cross-sectional views of the method steps of the method shown in FIGS. [Figure 9D] 9A-9C are side views of the method steps of the method shown in FIGS. [Figure 9E] 9A-9C are side views of the method steps of the method shown in FIGS. [Figure 9F] 9A-9C are side views of the method steps of the method shown in FIGS. [Figure 9G] 9A-9C are side views of the method steps of the method shown in FIGS. [Figure 9H] 9A-9C are side views of the method steps of the method shown in FIGS. [Figure 9I] 9A-9C are cross-sectional and side views of the method steps of the method shown in FIGS. [Figure 9J] 9A-9C are cross-sectional and side views of the method steps of the method shown in FIGS. [Figure 9K] 9A-9C are cross-sectional views of the method steps of the method shown in FIGS. [Figure 10] FIG. 1 is an elevational view of an expandable sheath and an exemplary housing according to the present disclosure. [Figure 11] FIG. 11 is an enlarged cross-sectional view of the distal end of the sheath of FIG. 10. [Figure 12A]14 taken along line 37-37 of FIG. 11 , showing a cross-sectional view of the distal end of the exemplary sheath of FIG. 14 , including a lubricant disposed between the sliding portion and the overlapping portion of the sheet, and a braid or coil that is not embedded in the elastomeric polymer layer; [Figure 12B] 17 is a cross-sectional view of the distal end of the exemplary sheath of FIG. 14 taken along line 37-37 of FIG. 11 , the cross-sectional view of the exemplary sheath including a lubricant disposed between the sliding portion and the overlapping portion of the sheet, and a lubricant disposed between the inner liner and the outer layer, and wherein the braid or coil is not embedded in the elastomeric polymer layer. [Figure 12C] 37-37 of FIG. 11 is a cross-sectional view of the distal end of the exemplary sheath of FIG. 14 taken along line 37-37 of FIG. 11 , the cross-sectional view of the exemplary sheath including a lubricant disposed between the inner liner and the outer layer, and in which the braid or coil, with or without the lubricant, is not embedded in the elastomeric polymer layer. [Figure 12D] 17 is a cross-sectional view of the distal end of the exemplary sheath of FIG. 14 taken along line 37-37 of FIG. 11 , the cross-sectional view of the exemplary sheath including a lubricant disposed between the sliding portion and the overlapping portion of the sheet, and a lubricant disposed between the inner liner and the outer layer, and wherein the braid or coil is at least partially embedded in the elastomeric polymer layer. [Figure 13A] 11 is a cross-sectional view of the proximal portion of the sheath of FIG. 10 taken along line 38-38 of FIG. 11, showing a cross-sectional view of an exemplary sheath including a lubricant disposed between the sliding portion and the overlapping portion of the sheet, and a braid or coil that is not embedded in the elastomeric polymer layer. [Figure 13B] 11 is a cross-sectional view of the proximal portion of the sheath of FIG. 10 taken along line 38-38 of FIG. 11, showing a cross-sectional view of an exemplary sheath including a lubricant disposed between the sliding portion and the overlapping portion of the sheet, and a lubricant disposed between the inner liner and the outer layer, and in which the braid or coil is not embedded in the elastomeric polymer layer. [Figure 13C]11 is a cross-sectional view of the proximal portion of the sheath of FIG. 10 taken along line 38-38 of FIG. 11 , showing a cross-sectional view of an exemplary sheath including a lubricant disposed between the inner liner and the outer layer, with no braid or coil embedded in the elastomeric polymer layer, with or without lubricant. [Figure 13D] 11 is a cross-sectional view of the proximal portion of the sheath of FIG. 10 taken along line 38-38 of FIG. 11, showing a cross-sectional view of an exemplary sheath including a lubricant disposed between the sliding portion and the overlapping portion of the sheet, and a lubricant disposed between the inner liner and the outer layer, with the braid or coil at least partially embedded in the elastomeric polymer layer. [Figure 14] 39 is a cross-sectional view of the sheath of FIG. 35 in a rest (unexpanded) configuration, taken along line 39-39 of FIG. 11. [Figure 15] 15 is a cross-sectional view of the sheath of FIG. 14 in an expanded configuration. [Figure 16] FIG. 1 illustrates experimental data for an exemplary sheath according to one embodiment. [Figure 17] FIG. 10 illustrates experimental data for an exemplary sheath in another embodiment. [Figure 18] 1A-1C illustrate an inner liner of an exemplary sheath in a collapsed and non-use configuration according to one aspect. [Figure 19] FIG. 19 is a cross-sectional view of an exemplary sheath in one embodiment, showing the inner liner and outer layer as shown in FIG. 18. [Figure 20A] 19A-19C illustrate exemplary manufacturing steps for an inner liner such as that shown in FIG. 18. [Figure 20B] 19A-19C illustrate exemplary manufacturing steps for an inner liner such as that shown in FIG. 18. [Figure 20C] 19A-19C illustrate exemplary manufacturing steps for an inner liner such as that shown in FIG. 18. [Figure 21A] 1 is a cross-sectional view of an exemplary sheath according to one embodiment, showing the inner liner and outer layer in a collapsed and non-use configuration. [Figure 21B]FIG. 1 is a side view of an exemplary sheath in one aspect, showing the inner liner and outer layer in a collapsed and non-use configuration. [Figure 22A] 1A-1C are schematic cross-sectional views of an exemplary sheath according to one embodiment, showing the sheath in a collapsed configuration (left) and an expanded configuration (right). [Figure 22B] 1 is a snapshot of an exemplary sheath according to one aspect, the exemplary sheath expanding during passage of a medical device. [Figure 23] 1 is a schematic cross-sectional view of an exemplary sheath according to one embodiment. [Figure 24A] 1 is a schematic cross-sectional view of an exemplary sheath according to one embodiment. [Figure 24B] 1 is a schematic cross-sectional view of an exemplary sheath according to one embodiment. [Figure 25A] 1 is a cross-sectional view of an inner liner for an exemplary sheath, the liner prior to forming the exemplary inner liner. [Figure 25B] 1 is a cross-sectional view of an inner liner for an exemplary sheath, the liner prior to forming the exemplary inner liner. [Figure 25C] 1 is a cross-sectional view of an inner liner for an exemplary sheath, the liner prior to forming the exemplary inner liner. [Figure 25D] 1 is a cross-sectional view of an inner liner for an exemplary sheath, the liner prior to forming the exemplary inner liner. [Figure 25E] 1 is a cross-sectional view of an inner liner for an exemplary sheath in a spiral configuration. [Figure 25F] 1 is a cross-sectional view of an inner liner for an exemplary sheath in a spiral configuration. [Figure 25G] 1 is a cross-sectional view of an inner liner for an exemplary sheath in a spiral configuration. [Figure 25H] 1 is a cross-sectional view of an inner liner for an exemplary sheath in a spiral configuration. [Figure 26]FIG. 2 is a side view of an exemplary lubricant pattern disposed on an exemplary inner liner according to one embodiment. [Figure 27] 1A-1C are cross-sectional views of an exemplary sheath in a collapsed configuration and an expanded configuration, with a bond between the inner liner and the outer layer. [Figure 28A] ~ [Figure 28C] 10A-10C illustrate various methods of forming a bond between the inner liner and outer layer of an exemplary sheath. [Figure 29A] ~ [Figure 29F] 25A-25D are schematic diagrams of the reinforcing jacket effect (FIGS. 25A-25D) and ballooning guard effect (FIGS. 25A-25B and 25E-25F) on the patient's anatomy. [Figure 30A] ~ [Figure 30B] FIG. 1 is a schematic diagram of a reinforcing jacket present in an exemplary sheath in one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present disclosure may be more readily understood by reference to the following detailed description, examples, drawings, and claims, as well as the accompanying descriptions. However, before the present articles, systems, and / or methods are disclosed and described, it should be understood that the disclosure is not limited to specific or exemplary aspects of the disclosed articles, systems, and / or methods, unless otherwise specified, which may, of course, vary. It should also be understood that the terminology used herein is for the purpose of describing aspects only, and is not intended to be limiting.

[0040] The following description of the present disclosure is provided as an enabling teaching of the present disclosure in its best currently known mode. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the disclosure described herein while still obtaining beneficial results of the present disclosure. It will also be apparent that some of the desirable benefits of the present disclosure can be obtained by selecting some of the features of the disclosure without utilizing other features. Thus, those skilled in the relevant art will recognize that many modifications and variations to the present disclosure are possible and may even be desirable in certain circumstances and are a part of this disclosure. Therefore, the following description is again provided by way of illustration of the principles of the present disclosure, and not in limitation thereof.

[0041] definition As used in this application and the claims, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. Thus, for example, reference to a "polymer" includes embodiments having two or more such polymers unless the context clearly dictates otherwise.

[0042] It is also to be understood that the terminology used herein is for the purpose of describing aspects only and is not intended to be limiting. As used in the specification and claims, the term "comprising" can include aspects "consisting of" and "consisting essentially of." Additionally, the term "includes" means "comprising."

[0043] The terms "for example" and "such as" and their grammatical equivalents are understood to be followed by the phrase "and without limitation," unless otherwise specified.

[0044] References in this specification and in the concluding claims to parts by weight of a particular element or component of a composition or article indicate the weight relationship between that element or component and any other element or component in the composition or article for which the parts by weight are expressed. Thus, in a composition or selected portion of a composition comprising 2 parts by weight of component X and 5 parts by weight of component Y, X and Y are present in a weight ratio of 2:5, and are present in such ratio regardless of whether additional components are included in the composition.

[0045] Weight percentages of ingredients are based on the total weight of the formulation or composition in which the ingredient is included, unless otherwise specified.

[0046] Ranges may be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. Further, it will be understood that the endpoints of each range are significant in relation to the other endpoint, and independently of the other endpoint.

[0047] As used herein, the term "substantially," when used in reference to a composition, refers to at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% by weight, based on the total weight of the composition, of the specified feature or component.

[0048] As used herein, the term "substantially," e.g., in the context of "substantially free," refers to a composition having less than about 1% by weight, e.g., less than about 0.5% by weight, less than about 0.1% by weight, less than about 0.05% by weight, or less than about 0.01% by weight of the recited material, based on the total weight of the composition.

[0049] As used herein, the terms "substantially identical reference composition" or "substantially identical reference article" refer to a reference composition or article that contains substantially identical components, excluding components of the present invention. In another exemplary embodiment, the term "substantially," for example, in the context of "substantially identical reference composition," refers to a reference composition that contains substantially identical components, where components of the present invention are substituted with components common in the art.

[0050] Furthermore, the terms "coupled" and "connected" generally mean electrically, electromagnetically, and / or physically (e.g., mechanically or chemically) connected or coupled, and do not exclude the presence of intermediate elements between the connected or coupled elements.

[0051] As used herein, the term "atraumatic" is generally known in the art and refers to a device or procedure that minimizes tissue damage.

[0052] As used herein, the terms or phrases "effective," "effective amount," or "conditions effective for" refer to such an amount or conditions that an effective amount can perform the function or property represented. As noted below, the exact amount or specific conditions required will vary from embodiment to embodiment, depending on recognized variables such as the materials employed and the process conditions observed. Thus, it is not always possible to specify an exact "effective amount" or "conditions effective for." However, an appropriate effective amount will be readily determined by one of ordinary skill in the art using only routine experimentation.

[0053] Although the operations of exemplary embodiments of the disclosed methods may be described in a particular order for convenient presentation, it should be understood that the disclosed embodiments may encompass orders of operations other than the particular order disclosed. For example, operations described in sequence may in some cases be rearranged or performed simultaneously. Furthermore, the description and disclosure provided in connection with one particular embodiment is not limited to that embodiment and may apply to any disclosed embodiment.

[0054] Moreover, for simplicity, the accompanying figures may not show the various ways in which the disclosed systems, methods, and apparatus can be used in combination with other systems, methods, and apparatus, which would be readily discernible by one of ordinary skill in the art based on this disclosure. Furthermore, the description may use terms such as "manufacture" and "provide" to describe the disclosed methods. These terms are high-level abstractions of actual operations that may be performed. The actual operations corresponding to these terms may vary depending on the particular implementation and would be readily discernible by one of ordinary skill in the art based on this disclosure.

[0055] sheath Disclosed herein is one embodiment of a sheath for delivering a medical device, the sheath having a proximal end and a distal end, the sheath having a) a first rest diameter d r and the second expansion diameter d ean inner liner defining a lumen having a first surface and an opposing second surface, the lumen configured to receive and pass a medical device, the inner liner comprising a sheet having a first portion having a first surface and an opposing second surface, a first end of the first portion divided into a first segment having the first surface and the opposing second surface and a third segment having the first surface and the opposing second surface, the second end of the first portion extending into the second segment having the first surface and the opposing second surface, the sheet wound into a spiral configuration such that at least a portion of the first surface of the second segment is adjacent to at least a portion of the second surface of the first segment. the first surface of the third segment overlaps with at least a portion of the second surface of the second segment, at least a portion of the first surface of the third segment overlaps with at least a portion of the second surface of the first segment, the first surface of the first portion extends into the first surfaces of the first segment, the second segment, and the third segment, and the second surface of the first portion extends into the second surfaces of the second and third segments, each segment configured to slidably move along one another when the medical device is passed through the lumen, and the sheet comprises an inner liner comprising a polymer layer and an outer layer.

[0056] In certain embodiments, the rest diameter d r can be substantially uniform along the longitudinal axis of the lumen. r varies along the longitudinal axis of the lumen and has a rest diameter d at the proximal end r is the rest diameter d at the distal end r In one disclosed embodiment, the expanded diameter d e In yet another embodiment, the sheath is configured to accommodate a medical device passing through the lumen. After the medical device has passed through the lumen, the sheath has a predetermined rest diameter d r It can be contracted up to

[0057] In one disclosed embodiment, the sheet of the sheath comprises high-density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or mixtures thereof. In yet another embodiment, the sheet can have a multi-layer structure. In yet another embodiment, the inner surface of the sheet is at least partially ribbed.

[0058] In one exemplary embodiment, the sheet is lubricious and has a coefficient of friction of less than about 0.5.

[0059] In yet another embodiment, a quantity of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer layer. In yet another disclosed embodiment, a quantity of a second lubricant is disposed between at least a portion of the overlapping portion of the sheet and at least a portion of the sliding portion of the sheet.

[0060] In still other disclosed aspects, the outer surface of the layer of elastomeric polymer can define at least a portion of the outer surface of the outer layer. In some disclosed aspects, at least a portion of the inner surface of the layer of elastomeric polymer is at least partially bonded to at least a portion of the outer surface of the inner liner sheet. In still other aspects, at least a portion of the inner surface of the layer of elastomeric polymer can define at least a portion of the inner surface of the outer layer. In other aspects, at least a portion of the braid or coil can define at least a portion of the inner surface of the outer layer.

[0061] In one disclosed embodiment, the sheath can further comprise a first strip of elastomeric polymer disposed along at least a portion of the longitudinal axis of the lumen between at least a portion of the outer surface of the sheet, not including the overlapping portion of the sheet, and the inner surface of the outer layer. In another embodiment, the sheath can further comprise a second strip of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the proximal end of the sheath and the inner surface of the outer layer. In another embodiment, the sheath can further comprise a third strip of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the distal end of the sheath and the inner surface of the outer layer.

[0062] In still other embodiments, the braid or coil is an expandable braid or coil. In still other embodiments, the braid or coil can comprise at least one filament comprising stainless steel, nitinol, a polymeric material, or a composite material. In certain embodiments, the at least one filament can be a round filament or a flat filament. In embodiments in which at least one filament comprises a polymeric material, the polymeric material can be polyester or nylon. In embodiments in which at least one filament is round, the round filament can have a diameter of less than about 0.015". In embodiments in which at least one filament is flat, the flat filament can have a height of less than about 0.006" and a width of greater than about 0.003" to about 0.015". In still other embodiments, the braid can have fewer than 50 crosses per inch (PIC). In still other embodiments, the PIC of the braid can vary along the longitudinal axis of the lumen.

[0063] In yet another embodiment, when at least one filament is nitinol, the nitinol is d e In still other embodiments, when at least one filament is stainless steel or nitinol, the filament can be configured to be atraumatic at least at the distal end of the sheath.

[0064] In yet other embodiments, the elastomeric polymer present in the outer layer comprises a styrenic elastomer, a polyurethane, a latex, a copolymer thereof, a blend thereof, or a coextrusion thereof. In one embodiment, the elastomeric polymer exhibits a Shore A durometer of less than 90. In certain embodiments, the braid or coil may be at least partially embedded within at least a portion of the layer of elastomeric polymer. Additionally, in other embodiments, a hydrophilic coating layer may be disposed on the outer surface of the outer layer.

[0065] Also disclosed herein is an embodiment including a method of making a sheath having a proximal end and a distal end. In a particular embodiment, the method of making such a sheath includes forming a variable diameter inner liner by winding a sheet having a first edge and a second edge, the sheet being defined by inner and outer surfaces in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming an overlapping portion, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet, and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen having a longitudinal axis; and forming an outer layer having a predetermined rest diameter d at least partially around the variable diameter inner liner such that an inner surface of the outer layer is positioned adjacent to an outer surface of the inner liner, the outer layer comprising a braid or coil and a layer of an elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface, wherein the variable diameter inner liner is configured to have a predetermined rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to expansion diameter d e The system is configured to extend to

[0066] In some exemplary embodiments, forming the variable inner liner includes winding the sheet onto a mandrel having a predetermined diameter to form a helical configuration, the predetermined diameter of the mandrel being equal to the predetermined diameter d of the inner liner. r In yet another embodiment, the rest diameter d r is substantially uniform along the longitudinal axis of the lumen. r varies along the longitudinal axis of the lumen and has a rest diameter d at the proximal end r is the rest diameter d at the distal end r In yet another embodiment, the expanded diameter d e In another aspect, the sheath formed by the methods disclosed herein has a predetermined rest diameter d after the medical device has passed through the lumen. r It can be contracted up to

[0067] In yet other aspects, forming the outer layer includes attaching a braid or coil to the inner liner. In yet other aspects, forming the outer layer further includes attaching an elastomeric polymer to the braid or coil. In some exemplary aspects, the methods disclosed herein can further include at least partially embedding the braid or coil within at least a portion of the layer of elastomeric polymer. In yet other exemplary aspects, forming the outer layer can include attaching a layer of elastomeric polymer to the braid or coil, and then attaching the layer of elastomeric polymer and the braid or coil onto the inner liner positioned on the mandrel. In such exemplary aspects, the method can further include at least partially embedding the braid or coil within at least a portion of the layer of elastomeric polymer before attachment to the inner liner. In other aspects, the method can further include at least partially embedding the braid or coil within at least a portion of the layer of elastomeric polymer after attachment to the inner liner. In still other aspects, the sheath is removed from the mandrel after the outer layer is attached to the inner liner and bonding is complete.

[0068] In other aspects, in the methods disclosed herein, the outer surface of the layer of elastomeric polymer can define at least a portion of the outer surface of the outer layer. In yet other aspects, in the methods disclosed herein, at least a portion of the inner surface of the layer of elastomeric polymer can define at least a portion of the inner surface of the outer layer. Additionally, aspects are disclosed herein where at least a portion of the braid or coil can define at least a portion of the inner surface of the outer layer.

[0069] In certain embodiments, the methods disclosed herein can further include bonding at least a portion of the inner surface of the layer of elastomeric polymer to at least a portion of the outer surface of the sheet of inner liner. In one embodiment, the bonding is effected by heating at a temperature of about 350°F to about 550°F for a time effective to form a bond between at least a portion of the outer layer and at least a portion of the inner liner.

[0070] One aspect of the methods described herein includes applying a first strip of elastomeric polymer to at least a portion of the outer surface of the sheet, not including the overlapping portion, along at least a portion of the longitudinal axis of the lumen before or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the inner liner. In yet another aspect, a second strip of elastomeric polymer can be applied to at least a portion of the outer surface of the sheet at the proximal end of the sheath before or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the inner liner. In yet another aspect, a third strip of elastomeric polymer can be applied to at least a portion of the outer surface of the sheet at the distal end of the sheath before or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the inner liner.

[0071] In yet another aspect, as described herein, a quantity of a first lubricant can be applied to at least a portion of the inner liner prior to forming the outer layer, such that the quantity of the first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer layer in the sheath. In another aspect, a quantity of a second lubricant is applied to at least a portion of the overlapping and sliding portion prior to forming the outer layer.

[0072] In other embodiments, the methods described herein include high-density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or mixtures thereof. In still other embodiments, the sheet can have a multi-layer structure. In still other embodiments, the inner surface of the sheet can be at least partially ribbed. In still other embodiments, the sheet can be lubricious and have a coefficient of friction of less than about 0.5.

[0073] In still other embodiments, the methods disclosed herein include a braid or coil, wherein the braid or coil is an expandable braid or coil. In still other embodiments, the braid or coil of the disclosed methods can include at least one filament comprising stainless steel, nitinol, a polymeric material, or a composite material. In certain embodiments, at least one of the filaments can be a round filament or a flat filament. In certain embodiments, the polymeric material present in the braid can be polyester or nylon. In embodiments where at least one filament is a round filament, such filament can have a diameter of less than about 0.015". In still other embodiments, when at least one filament is a flat filament, such filament can have a height of less than about 0.006" and a width of greater than about 0.003" to about 0.015". In embodiments of the methods disclosed herein, the braid can have fewer than 50 crossovers per inch (PIC). In further exemplary embodiments, the PIC can vary along the longitudinal axis of the lumen.

[0074] In embodiments in which at least one filament comprises nitinol, the nitinol is e In embodiments in which at least one filament is stainless steel or nitinol, the filament is configured to be atraumatic at least at the distal end of the sheath.

[0075] In yet another aspect, the methods disclosed herein include an elastomeric polymer including a styrenic elastomer, a polyurethane, a latex, a copolymer thereof, a blend thereof, or a coextrusion thereof. In yet another aspect, the elastomeric polymer exhibits a Shore A durometer of less than 90. In yet another aspect, the method can further include disposing a hydrophilic coating layer on an outer surface of the layer of elastomeric polymer.

[0076] In some methods, a soft tip portion may be coupled to the distal end of the expandable sheath to facilitate passing the expandable sheath through the patient's vasculature.

[0077] The expandable sheath of the disclosed embodiments can minimize trauma to the vessel by allowing a portion of the introducer sheath to temporarily expand to accommodate a delivery system and then return to its original diameter once the device has passed. Some embodiments can include a sheath with a smaller profile (e.g., a smaller diameter in the rest configuration) than that of prior art introducer sheaths. Furthermore, embodiments of the present disclosure can shorten the length of time required for the procedure and reduce the risk of tearing the vessel longitudinally or radially or displacing plaque, since only one sheath is required rather than multiple sheaths of different sizes. Embodiments of the presently disclosed expandable sheath can avoid the need for multiple insertions to expand the vessel. Such expandable sheaths can be useful in many types of minimally invasive procedures, such as any procedure requiring the introduction of an apparatus into a subject's vessel. For example, sheaths may be used to introduce other types of delivery apparatus for placing various types of intraluminal devices (e.g., stents, prosthetic heart valves, stent grafts, etc.) into many types of vascular and non-vascular body lumens (veins, arteries, esophagus, ducts of the biliary tree, intestines, urethra, fallopian tubes, other endocrine or exocrine ducts, etc.).

[0078] FIG. 1 illustrates a sheath 8 according to the present disclosure used with a representative delivery apparatus 10 for delivering a prosthetic device 12, such as a tissue heart valve, to a patient. The apparatus 10 can include a steerable guide catheter 14 (also referred to as a flex catheter), a balloon catheter 16 extending through the guide catheter 14, and a nose catheter 18 extending through the balloon catheter 16. The guide catheter 14, balloon catheter 16, and nose catheter 18 in the illustrated embodiment are adapted to slide longitudinally relative to one another to facilitate delivery and positioning of the valve 12 at an implantation site within the patient, as described in detail below. Generally, the sheath 8 is inserted into a blood vessel, such as a transfemoral vessel, and advanced through the patient's skin so that the distal end of the sheath 8 is inserted into the blood vessel. The sheath 8 can include a hemostatic valve at the opposite proximal end of the sheath. The delivery apparatus 10 can be inserted into the sheath 8, and the prosthetic device 12 can then be delivered and implanted within the patient.

[0079] 2A and 2B show cross-sectional views of two exemplary sheath embodiments disclosed herein for use with a delivery device such as that shown in FIG. 1. FIG. 2C shows a perspective view of one embodiment of an inner liner 202 for use with the disclosed sheath. As shown in FIGS. 2A-2C, in some embodiments, the disclosed sheath comprises an inner liner 202 wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, forming an overlapping portion 202c, a first edge 202a of the sheet being slidable along at least a portion of the inner surface of the sheet, and a second edge 202b being slidable along at least a portion of the outer surface of the sheet. Sheaths such as those shown in FIGS. 2A and 2B can further include an outer layer comprising a braid (or coil) 204 and a layer 206 of an elastomeric polymer. In one embodiment, as shown in Figure 2A, the outer layer can include a braid (or coil) 204 that is not embedded in the layer of elastomeric polymer 206. In other embodiments, as shown in Figure 2B, the outer layer can include a braid (or coil) that is embedded in the layer of elastomeric polymer 206.

[0080] The inner liner 202 defines a lumen 201 through which a delivery device can be advanced into a patient's vasculature to deliver, remove, repair, and / or replace a prosthetic device. The disclosed sheaths may also be useful for other types of minimally invasive procedures, such as any procedure requiring the introduction of a device into a subject's vasculature. For example, the disclosed sheaths may also be used to introduce other types of delivery devices for placing various types of endoluminal devices (e.g., stents, stent grafts, etc.) into many types of vascular and non-vascular body lumens (veins, arteries, esophagus, ducts of the biliary tree, intestines, urethra, fallopian tubes, other endocrine or exocrine ducts, etc.).

[0081] In still other embodiments, the sheet used to make the inner liner 202 can comprise high-density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or mixtures thereof. In still other embodiments, the sheet can comprise one or more layers. In some embodiments, when one or more layers are present, each layer can comprise the same or different polymers. In still other embodiments, the sheet can have a predetermined thickness, which can be defined by one of ordinary skill in the art depending on the particular application. In certain embodiments, the predetermined thickness of the inner liner can be from about 0.002 inches to about 0.025 inches, including exemplary values ​​of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, about 0.01, about 0.015, and about 0.02 inches. Furthermore, it is understood that the predetermined thickness of the sheet forming the inner liner 202 can vary depending on the desired amount of radial expansion as well as the required strength.

[0082] In still other embodiments, the inner surface of the sheet can be at least partially ribbed. In still other embodiments, the sheet can be lubricious. In some exemplary embodiments, the sheet forming the inner liner can have a coefficient of friction of less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, less than about 0.1, or less than about 0.05, or even less than about 0.01. It is further understood that the sheet can have a coefficient of friction having any value between any two of the above values. Such a liner can facilitate passage of a delivery device through the lumen 201 of the disclosed sheath. In some further exemplary embodiments, materials that can be used to form a suitable lubricious inner liner include materials that can reduce the coefficient of friction of the inner liner 202, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Suitable materials for the lubricious liner also include other materials that desirably have a coefficient of friction of about 0.1 or less, about 0.09 or less, about 0.08 or less, about 0.07 or less, about 0.05 or less, about 0.04 or less, about 0.03 or less, about 0.02 or less, or about 0.01 or less.

[0083] In still other embodiments, the outer layer, comprising the braid or coil and the layer of elastomeric polymer, can have any predetermined thickness. It is understood that the predetermined thickness of the outer layer can depend on the particular application of the sheath. For example, without limitation, the thickness of the inner liner 202 and the outer layer, comprising the braid (or coil) 204 and the layer of elastomeric material 206, can also vary depending on the particular application of the disclosed sheath. In some embodiments, the thickness of the inner liner 202 ranges from about 0.0005 inches to about 0.010 inches, including exemplary values ​​of about 0.0006, about 0.0007, about 0.0008, about 0.0009, about 0.001, about 0.002, about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, and about 0.009 inches; in one particular embodiment, the thickness can be about 0.002 inches. The outer layer comprising the braid (or coil) 204 and the layer of elastomeric material 206 can have a thickness of about 0.002 inches to about 0.015 inches, including exemplary values ​​of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, and about 0.01 inches.

[0084] It is understood that the inner liner can have any shape or configuration depending on the desired application and the size of the delivery apparatus and prosthetic device. Furthermore, it is understood that the inner liner is not limited to a particular shape or configuration. In yet other embodiments, the outer layer comprising a braid or coil and a layer of elastomeric polymer can conform to the shape or configuration of the inner liner. In certain embodiments, the sheaths disclosed herein have a rest diameter d r and outer diameter d0. As disclosed herein, the rest diameter d r is defined by an inner liner, while the outer diameter can be defined by the inner liner and an outer layer, the outer layer comprising a braid or coil and a layer of elastomeric polymer.

[0085] Rest diameter d of inner liner 202r can vary depending on the application and size of the delivery apparatus and prosthetic device. Figures 3A-3C show various configurations and shapes of inner liners. In some embodiments, as shown in Figure 3B, the rest diameter d r It will be appreciated that the rest diameter d is substantially uniform along the longitudinal axis of the lumen without variation from the proximal end 308 to the distal end 306. In yet another embodiment, as shown in Figures 3A and 3C, the rest diameter d r can vary along the longitudinal axis of the lumen (e.g., d in FIG. 3A). r1 and d r2 , or d shown in Figure 3C r1 , d r2 , d r3 , and d r4 In certain embodiments, the rest diameter d at the proximal end 304 or 312 r1 is located at the distal end 302 or 310d r As shown in Figure 3A, the rest diameter d r2 or d as shown in Figure 3C r4 In yet other embodiments, when the outer layer conforms to the shape of the inner liner, the outer diameter d0 (not shown) includes the overall diameter of the inner liner and outer layer. In such embodiments, the outer diameter d0 is defined depending on the particular application of the sheath. r Similarly, the outer diameter d0 of the non-use sheath disclosed herein can be substantially uniform (constant) along the longitudinal axis of the lumen without varying from the proximal end to the distal end (not shown). In an alternative embodiment, the original unexpanded outer diameter d0 of the disclosed sheath can be substantially uniform (constant) along the longitudinal axis of the lumen without varying from the proximal end to the distal end (not shown). r In some embodiments, the rest diameter d r Similarly, the original unexpanded outer diameter may decrease along a gradient from the proximal end to the distal end, or may gradually step down along the length of the sheath, with the largest original unexpanded outer diameter d0 near the proximal end and the smallest original unexpanded outer diameter d0 near the distal end.

[0086] In some embodiments, the rest diameter dr can range from about 0.005 inches to about 0.400 inches, including exemplary values ​​of about 0.01, about 0.02, about 0.03, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09, about 0.1, about 0.2, and about 0.3 inches. As noted above, in certain embodiments, the sheath may be configured with various d r In such an embodiment, the inner liner may include r can have any value between any two of the above values ​​and may depend on the particular application and size and shape of the delivery device and prosthetic device. Depending on the size requirements of the delivery device for different applications, different sheaths may have different expanded and unexpanded rest diameters d r and outer diameter d0. Additionally, some embodiments may provide for greater or lesser expansion depending on the particular design parameters, materials, and / or configurations used.

[0087] As disclosed herein, the outer layer of the sheath has an inner surface and an outer surface. The outer layer of the disclosed sheath extends around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the inner liner. As disclosed herein, the outer layer comprises a braid (or coil) 204 (as shown in FIGS. 2A and 2B ) and a layer 206 of an elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface. In certain embodiments, the braid or coil can be an expandable braid or coil. In still other embodiments, the braid or coil can include at least one filament including stainless steel, nitinol, a polymeric material, or a composite material. In certain non-limiting embodiments, the braid or coil includes filaments including nitinol and / or other shape memory alloys. In still other non-limiting embodiments, the braid can have filaments including polyester or nylon. In still other exemplary embodiments, the braid can include filaments including Spectra fibers, polyethylene fibers, aramid fibers, or combinations thereof.

[0088] It is understood that the braid or coil can have any configuration known in the art. In certain embodiments, the braid (or coil) 204 is generally a thin, hollow, substantially cylindrical tube containing an arrangement, pattern, structure, or configuration of filaments or struts, although other shapes may be used. Suitable filaments may be circular and have a diameter of less than about 0.015", less than about 0.01", less than about 0.008", less than about 0.005", less than about 0.002", less than about 0.001", less than about 0.0008", or less than about 0.0005". In still other embodiments, suitable filaments are circular and may range from about 0.0005" inches thick to about 0.015" thick, including exemplary values ​​of about 0.0006", about 0.0007", about 0.0008", about 0.0009", about 0.001", about 0.002", about 0.003", about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014". In still other embodiments, suitable filaments may range from about 0.0005" inches thick to about 0.015" thick, including exemplary values ​​of about 0.0006", about 0.005", about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014". The flat filaments can have heights of less than 3", less than about 0.001", less than about 0.0009", less than about 0.0008", less than about 0.0007", less than about 0.0006", and about 0.0005". In still other embodiments, the flat filaments can have widths of greater than about 0.003" to about 0.015", including exemplary values ​​of about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014". However, other shapes and sizes are also suitable in certain embodiments.

[0089] In still other embodiments, the braid may have fewer than 50, fewer than 40, fewer than 30, fewer than 20, or fewer than 10 crossovers per inch (PIC). In still other embodiments, the braid may have a PIC number of 10 to 2, with exemplary values ​​of 9, 8, 7, 6, 5, 4, and 3. In still other embodiments, the PIC may vary along the longitudinal axis of the lumen. In still other embodiments, the braid pattern may vary along the longitudinal axis of the lumen. In embodiments where the braid or coil includes filaments that are nitinol, the nitinol may have an expanded diameter d e In yet other embodiments, when the filaments comprise stainless steel or nitinol, the filaments are configured to be atraumatic at least at the distal end of the sheath. FIGS. 4A-4D show partial elevational views of various configurations of the braid 28. It is understood that the configuration of the braid 28 may vary from section to section along the length of the sheath. Furthermore, it is understood that the configurations shown in FIGS. 4A-4D are not necessarily drawn to scale and represent merely exemplary, non-limiting embodiments. It is further understood that the braid is configured to provide torqueability for the sheath during insertion of the prosthetic device.

[0090] In yet other embodiments, the outer layer comprises a layer 206 of an elastomeric polymer, as shown in FIGS. 2A and 2B. In certain embodiments, the elastomeric polymer may include a styrenic elastomer, a polyurethane, a latex, a copolymer thereof, a blend thereof, or a coextrusion thereof. In certain non-limiting embodiments, the elastomeric polymer may include a polyether block ester copolymer, a polyester, a polyvinyl chloride, a thermoset silicone, a polyisoprene rubber, a polyolefin, another medical-grade polymer, or a combination thereof. In still other embodiments, the elastomeric polymers described herein may have any useful additive. In certain embodiments, the elastomeric polymer may include at least one friction-reducing additive. In some exemplary embodiments, the friction-reducing additive may include, for example, BaSC, ProPell™, PTFE, any combination thereof, and the like. It is understood that this list of friction-reducing additives is not limiting, and any friction-reducing additive known in the art may be utilized.

[0091] It is understood that the hardness of each layer of the disclosed sheath can also vary depending on the particular application and desired properties of the sheath. In some embodiments, the elastomeric polymer layer 206 has a Shore hardness of less than 90 durometer, less than 80 durometer, less than 70 durometer, less than 60 durometer, less than 50 durometer, less than 40 durometer, less than 30 durometer, or less than 20 durometer. In yet other exemplary embodiments, the elastomeric polymer layer 206 has a Shore hardness of about 25 durometer to about 75 durometer, including exemplary values ​​of about 30 durometer, about 35 durometer, about 40 durometer, about 45 durometer, about 50 durometer, about 55 durometer, about 60 durometer, about 65 durometer, and about 70 durometer.

[0092] Alternative embodiments of sheaths for introducing prosthetic devices are also described. For example, Figures 5A-5B show cross-sectional views of inner liners 500A and 500B of the disclosed sheaths in non-use and use configurations (Figures 5A and 5B, respectively). When a prosthetic device is introduced into the inner liner, first edge 502 and second edge 504 slide along the inner liner, reducing the inner liner to a rest diameter d. r to expansion diameter d e , thereby shortening the overlapping portion 506 of the inner liner. e It will be understood that the sheath is configured to accommodate a medical device passing through the lumen. In yet another embodiment, the sheath has a predetermined rest diameter d after the medical device has passed through the lumen. r Can be deflated up to

[0093] In certain embodiments, an amount of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer layer. In yet other embodiments, an amount of a second lubricant is disposed between at least a portion of the overlapping portion of the sheet and at least a portion of the sliding portion of the sheet. It is understood that the first lubricant and the second lubricant can be the same or different. In certain non-limiting embodiments, the first and / or second lubricant can include Christo Lube, supplied by ECL, or MED10 / 6670, supplied by Nusil. In still other embodiments, it is understood that the amount of the first and / or second lubricant can be readily determined by one skilled in the art.

[0094] In yet another aspect, the outer surface of the layer of elastomeric polymer defines at least a portion of the outer surface of the outer layer. In yet another aspect, at least a portion of the inner surface of the layer of elastomeric polymer is at least partially bonded to at least a portion of the outer surface of the inner liner sheet. In one aspect, at least a portion of the inner surface of the layer of elastomeric polymer defines at least a portion of the inner surface of the outer layer. In another aspect, at least a portion of the braid or coil defines at least a portion of the inner surface of the outer layer. It is understood that the outer layer of the disclosed sheath is configured to provide hemostasis and prevent bleeding in a patient during a procedure.

[0095] 6A-6D illustrate another alternative embodiment of a sheath for introducing a prosthetic device. FIG. 6A illustrates a sheath 600A comprising an inner liner 602 having a first edge 602a, a second edge 602b, and an overlapping portion 602c, with the inner and outer surfaces of the inner liner overlapping each other. The sheath 600A further includes a quantity of a second lubricant 608, as disclosed herein, disposed between the sliding portion and the overlapping portion of the inner sheath. The sheath further includes a braid 604 and a layer 606 of elastomeric polymer. In this exemplary embodiment, the braid 604 is not embedded in the layer 606 of elastomeric polymer. FIG. 6B illustrates an alternative embodiment of a sheath 600B, in which a quantity of a first lubricant 610 is applied between the inner liner and the outer layer comprising the braid 604 and the layer 606 of elastomeric polymer. An additional embodiment of a sheath 600C is shown in FIG. 6C. In this embodiment, the sheath 600C includes an inner liner 602 having a first edge 602a, a second edge 602b, and an overlapping portion 602c, with the inner and outer surfaces of the inner liner overlapping each other. The sheath further includes a braid 604 and a layer of elastomeric polymer 606, which together form the outer layer of the sheath. The sheath 600C further includes a quantity of a first lubricant 610, as disclosed herein, disposed between the outer layer of the inner sheath and the inner liner. In this exemplary embodiment, the braid 604 is not embedded in the layer of elastomeric polymer 606. In the exemplary embodiment shown in FIG. 6D, an exemplary sheath 600D includes a braid 604 embedded within the layer of elastomeric polymer 606.

[0096] In still other embodiments, the sheaths of the present disclosure can include a hemostatic valve inside the sheath lumen at or near the proximal end of the sheath (not shown). Additionally, exemplary sheaths disclosed herein can include a soft tip at the distal end of the sheath (not shown). Such a soft tip can be provided with a lower hardness than the remainder of the sheath. In some embodiments, the soft tip can have a Shore hardness of about 25D to about 40D, including exemplary values ​​of about 26D, about 27D, about 28D, about 29D, about 30D, about 31D, about 32D, about 33D, about 34D, about 35D, about 36D, about 37D, about 38D, and about 39D. In still other embodiments, the soft tip can have a Shore hardness of about 25A to about 40A, including exemplary values ​​of about 26A, about 27A, about 28A, about 29A, about 30A, about 31A, about 32A, about 33A, about 34A, about 35A, about 36A, about 37A, about 38A, and about 39A.

[0097] In certain embodiments, the outer layer and inner liner may be bonded together or otherwise physically associated with one another. It is understood that the amount of adhesion between the inner liner 602 and the outer polymer layer, comprising the braid 604 and the layer of elastomeric polymer 606, may vary across the surface of the layer. The bond between the layers may be created, for example, by thermal bonding. In certain embodiments, the bond may be facilitated by the presence of additional portions of elastomeric polymer. For example, in certain embodiments, a sheath such as those described herein and shown in FIGS. 6H-6I may further comprise a first strip 611 of elastomeric polymer, the first strip 611 being disposed along at least a portion of the longitudinal axis of the lumen between at least a portion of the outer surface of the sheet, not including the overlapping portion 602c of the sheet, and the inner surface of the outer layer. In such embodiments, the bond between the outer layer and the inner liner may be facilitated by the first strip of elastomeric polymer. In still other embodiments, the sheath can further comprise a second strip 611 of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the proximal end of the sheath and the inner surface of the outer layer (FIGS. 6E-6F). In still other embodiments, the sheath can further comprise a third strip 611 of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the distal end of the sheath and the inner surface of the outer layer (FIGS. 6E and 6G). Again, in such embodiments, bonding between the outer layer and the inner liner can be facilitated by the second and / or third strips of elastomeric polymer.

[0098] In use, the expanded diameter d of about 3 Fr to about 26 Fr e The inner liner 602 has a lumen diameter d that is expandable to r Sheaths of the present disclosure may be utilized having expanded diameters d eExemplary values ​​of the expanded outer diameter include about 5 Fr, about 8 Fr, about 10 Fr, about 12 Fr, about 15 Fr, about 18 Fr, about 20 Fr, about 22 Fr, and about 25 Fr. The expanded diameter may vary somewhat along the length of the disclosed sheaths. For example, the expanded outer diameter at the proximal end of the sheath may range from about 3 Fr to about 28 Fr, including exemplary values ​​of about 5 Fr, about 8 Fr, about 10 Fr, about 12 Fr, about 15 Fr, about 18 Fr, about 20 Fr, about 22 Fr, and about 25 Fr, while the expanded outer diameter at the distal end of the sheath may range from about 3 Fr to about 25 Fr, including exemplary values ​​of about 8 Fr, about 10 Fr, about 12 Fr, about 15 Fr, about 18 Fr, about 20 Fr, and about 22 Fr. Embodiments of the disclosed sheaths can be expanded to an expanded outer diameter that is about 10% larger than the original unexpanded outer diameter to about 100% larger than the original unexpanded outer diameter, with exemplary values ​​including about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, and about 95% larger than the original unexpanded outer diameter.

[0099] As noted above, it is understood that the disclosed sheaths can be expanded from their rest positions. The expansion of the disclosed sheaths can range from about 10% or less to about 430% or more of the rest diameter d r In certain embodiments, the expansion of the sheath can result in an expansion of the rest diameter d by about 10% or less, by about 9% or less, by about 8% or less, by about 7% or less, by about 6% or less, by about 5% or less, by about 4% or less, by about 3% or less, by about 2% or less, by about 1% or less. r In still other embodiments, the expansion of the disclosed sheaths can result in an expansion of the rest diameter d by about 10% or more, about 20% or more, about 30% or more, about 40% or more, about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 100% or more, about 125% or more, about 150% or more, about 175% or more, about 200% or more, about 225% or more, or about 250% or more. rThis may result in an expansion of

[0100] Similar to the previously disclosed embodiments, the embodiment shown in FIGS. 6A-6D can be configured with a variety of rest diameters d r and outer diameter d0. In some embodiments, the outer diameter d0 of the sheath gradually decreases from the proximal end of the sheath to the distal end of the sheath. For example, in one embodiment, the outer diameter d0 can gradually decrease from about 26 Fr at the proximal end to about 18 Fr at the distal end. The sheath diameter d0 can gradually transition over substantially the entire length of the sheath. In other embodiments, the transition or reduction in the sheath diameter can occur only along a portion of the length of the sheath. For example, the transition can occur along the length from the proximal end to the distal end, which length can range from about 0.5 inches to approximately the entire length of the sheath, including any value between any two of the values ​​above. In still other embodiments, d0 is minimal and constant along the portion of the sheath that passes through the vasculature. In such embodiments, the tapered portion is about 4 inches or less on the proximal side of the sheath.

[0101] In some embodiments, the outer layer, including the braid and the layer of elastomeric polymer, can comprise the same material or combination of materials along its entire length. In alternative embodiments, the material composition of the outer layer can vary along the length of the sheath. For example, the outer layer can be provided with one or more segments, with the composition varying from segment to segment. For example, in one segment, the braid can comprise Nitinol having a different PIC number than another segment. In yet another exemplary embodiment, the layer of elastomeric material in one segment can be different from the layer of elastomeric material in another segment. In yet another exemplary embodiment, one segment of the sheath can comprise a braid or coil embedded within a layer of elastomeric polymer material, while another segment can comprise a braid or coil that is not embedded within a layer of elastomeric polymer material. It is understood that the exemplary sheaths disclosed herein are not limiting. In certain exemplary embodiments, the sheath can comprise n segments, each of which can be the same or different. In yet another exemplary embodiment, the durometer rating of the outer layer composition can also vary along the length of the sheath, such that the segment near the proximal end comprises a harder material or combination of materials, while the segment near the distal end comprises a softer material or combination of materials. This can enable the sheath to have a relatively soft distal tip at the point of entry into the patient's vessel, but a relatively stiff proximal end at the point of introduction of the delivery device.

[0102] 10 and 11 illustrate an expandable sheath 100 according to the present disclosure that can be used with a delivery device for delivering a prosthetic device, such as a tissue heart valve, into a patient. Generally, the delivery device can include a steerable guide catheter (also called a flex catheter) (e.g., as shown in FIG. 1 ), a balloon catheter extending through the guide catheter, and a nose catheter extending through the balloon catheter. The guide catheter, balloon catheter, and nose catheter can be adapted to slide longitudinally relative to one another to facilitate delivery and positioning of the valve at an implantation site within the patient's body. However, it should be noted that the sheath 100 can be used with any type of elongated delivery device used to implant balloon-expandable prosthetic valves, self-expanding prosthetic valves, and other prosthetic devices. Generally, the sheath 100 can be inserted into a blood vessel (e.g., the femoral or iliac artery) by advancing it through the patient's skin so that the soft-tip portion 102 at the distal end 104 of the sheath 100 is inserted into the blood vessel. The sheath 100 may also include a proximal flared end 114 to facilitate mating with the introducer housing 101 and the catheter (e.g., the proximal flared end 114 may provide a compression fit over the housing tip and / or the proximal flared end 114 may be secured to the housing 101 via a nut or other fastener or by coupling the proximal end of the sheath to the housing). The introducer housing 101 may house one or more valves, as known in the art, that form a seal around the outer surface of a delivery device when inserted through the housing. A delivery device may be inserted into and through the sheath 100, allowing the prosthetic device to be advanced through the patient's vasculature and implanted within the patient.

[0103] In an exemplary embodiment, the sheath 100 comprises an inner liner 108 and an outer layer 110 disposed about the inner liner 108. The outer layer 110 comprises a braid (or coil) 111 and a layer 113 of an elastomeric polymer. Figure 11 shows one non-limiting embodiment in which the braid (or coil) 111 is embedded in the layer 113 of an elastomeric polymer. The inner liner 108 has a rest diameter d r The sheath 100 defines a lumen having a rest diameter d, through which a delivery device is advanced into a patient's vessel and moved in a direction along the longitudinal axis X to deliver, remove, repair, and / or replace a prosthetic device. As the prosthetic device passes through the sheath 100, the sheath extends to a rest diameter d. r to expansion diameter d e After the prosthetic device has passed through a particular location in the sheath 100, each successively expanded portion or segment of the sheath 100 expands at least partially to the rest diameter d. r As such, sheath 100 may be considered self-expanding because it does not require the use of balloons, dilators, and / or obturators to expand.

[0104] As shown herein, the inner and outer layers 108, 110 can include any of the materials disclosed above.

[0105] Additionally, some embodiments of the sheath 100 can include an external hydrophilic coating on the outer surface of the outer layer 110. Such a hydrophilic coating can facilitate insertion of the sheath 100 into a patient's blood vessel. Examples of suitable hydrophilic coatings include Harmony™ Advanced Lubricity Coatings and other Advanced Hydrophilic Coatings available from SurModics, Inc., Eden Prairie, MN. DSM Medical Coatings (available from Koninklijke DSM NV, Heerlen, the Netherlands) and other hydrophilic coatings (e.g., PTFE, polyethylene, polyvinylidene fluoride) are also suitable for use with the sheath 100.

[0106] As best seen in FIG. 11 , the soft-tip portion 102, in some embodiments, can comprise low-density polyethylene (LDPE) and can be configured to minimize trauma or damage to a patient's blood vessels as the sheath is guided through the vasculature. For example, in some embodiments, the soft-tip portion 102 can be slightly tapered to facilitate passage through a blood vessel. The soft-tip portion 102 can be secured to the distal end 104 of the sheath 100, such as by thermally bonding the soft-tip portion 102 to the inner and outer layers of the sheath 100. Such a soft-tip portion 102 can be provided with a lower hardness than other portions of the sheath 100. In some embodiments, the soft-tip 102 can have a Shore hardness of about 25 A to about 40 A, including exemplary values ​​of about 28 A, about 30 A, about 32 A, about 35 A, and about 38 A. It is further understood that the Shore hardness can have any value between any two of the above values. In still other embodiments, the soft tip 102 can have a Shore hardness of about 25D to about 40D, including exemplary values ​​of about 28D, about 30D, about 32D, about 35D, and about 38D. The tip portion 102 is configured to be radially expandable to allow the prosthetic device to pass through the distal opening of the sheath 100.

[0107] 11 , the sheath 100 can optionally include at least one radiopaque filler or marker, such as a discontinuous or C-shaped band 112, positioned near the distal end 104 of the sheath 100. The marker 112 can be associated with the inner liner and / or the outer layers 108, 110 of the sheath 100. Such radiopaque tip markers can include materials suitable for use as radiopaque fillers, platinum, iridium, platinum / iridium alloys, stainless steel, other biocompatible metals, or combinations thereof. Materials suitable for use as radiopaque fillers or markers include, for example, barium sulfite, bismuth trioxide, titanium dioxide, bismuth subcarbonate, or combinations thereof. The radiopaque filler may be mixed with or embedded in the layer of elastomeric polymer used to form the outer layer and may comprise from about 5% to about 45% by weight of the outer layer, including exemplary values ​​of about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, and about 40% by weight of the outer polymeric tubular layer. In some embodiments, more or less radiopaque material may be used depending on the particular application.

[0108] 12A-12B show cross-sectional views of the sheath 100 as seen near the distal end 104 of the sheath 100. FIG. 12A shows a sheath 1200A comprising an inner liner 1202 having a first edge 1202a and a second edge 1202b and an overlapping portion 1202c, the inner and outer surfaces of the inner liner overlapping one another. The sheath 1200A further comprises a quantity of a second lubricant 1208, as disclosed herein, disposed between the sliding portion and the overlapping portion of the inner sheath. The sheath further comprises a braid (or coil) 1204 and a layer 1206 of elastomeric polymer. In this exemplary embodiment, the braid (or coil) 1204 is not embedded in the layer 1206 of elastomeric polymer. FIG. 12B shows an alternative embodiment of a sheath 1200B in which a quantity of a first lubricant 1210 is applied between the inner liner and an outer layer comprising a braid (or coil) 1204 and a layer of elastomeric polymer 1206. An additional embodiment of a sheath 1200C is shown in FIG. 12C. In this embodiment, the sheath 1200C comprises an inner liner 1202 having a first edge 1202a and a second edge 1202b and an overlapping portion 1202c, with the inner and outer surfaces of the inner liner overlapping each other. The sheath further comprises a braid (or coil) 1204 and a layer of elastomeric polymer 1206, which together form the outer layer of the sheath. The sheath 1200C further comprises a quantity of a first lubricant 1210, as disclosed herein, disposed between the outer layer of the inner sheath and the inner liner. In this exemplary embodiment, the braid (or coil) 1204 is not embedded in the layer of elastomeric polymer 1206. In the exemplary embodiment shown in FIG. 12D, an exemplary sheath 1200D comprises a braid (or coil) 1204 embedded within the layer of elastomeric polymer 1206.

[0109] 13A-13D are cross-sectional views of the proximal portion of the sheath of FIG. 10 taken along line 38-38. FIG. 13A shows a sheath 1300A including an inner liner 1302 having a first edge 1302a and a second edge 1302b and an overlapping portion 1302c, the inner and outer surfaces of the inner liner overlapping each other. The sheath 1300A further includes a quantity of a second lubricant 1308, as disclosed herein, disposed between the sliding portion and the overlapping portion of the inner sheath. The sheath further includes a braid (or coil) 1304 and a layer 1306 of elastomeric polymer. In this exemplary embodiment, the braid (or coil) 1304 is not embedded in the layer 1306 of elastomeric polymer. FIG. 13B shows an alternative embodiment of a sheath 1300B in which a quantity of a first lubricant 1310 is applied between the inner liner and an outer layer comprising a braid (or coil) 1304 and a layer of elastomeric polymer 1306. An additional embodiment of a sheath 1300C is shown in FIG. 13C. In this embodiment, the sheath 1300C comprises an inner liner 1302 having a first edge 1302a and a second edge 1302b and an overlapping portion 1302c, with the inner and outer surfaces of the inner liner overlapping each other. The sheath further comprises a braid (or coil) 1304 and a layer of elastomeric polymer 1306, which together form the outer layer of the sheath. The sheath 1300C further comprises a quantity of a first lubricant 1310, as disclosed herein, disposed between the outer layer of the inner sheath and the inner liner. In this exemplary embodiment, the braid (or coil) 1304 is not embedded in the layer of elastomeric polymer 1306. In the exemplary embodiment shown in FIG. 13D, an exemplary sheath 1300D comprises a braid (or coil) 1304 embedded within the layer of elastomeric polymer 1306.

[0110] In yet other embodiments, as shown in FIG. 14, sheath 1400, whether having a braid or coil embedded within a layer of elastomeric polymer (as shown in FIG. 14A) or a braid or coil not embedded within a layer of elastomeric polymer (not shown), is configured to expand from a rest configuration to an expanded configuration as shown in FIG. 15. In such embodiments, first and second edges (1502a and 1502b) of the inner liner slide to reduce the length of overlap. In some exemplary embodiments, this movement can be facilitated by the presence of a first and / or second lubricant, as disclosed above.

[0111] The sheaths disclosed herein can be configured to locally expand at specific locations corresponding to the location of a medical device along the length of the lumen, and then locally contract as the medical device passes that specific location. Thus, a bulge may be visible, moving longitudinally along the length of the sheath as the medical device is introduced through the sheath, exhibiting continuous, localized expansion and contraction as the device moves down the length of the sheath. In some embodiments, each segment of the sheath locally contracts after removal of the radially outward (insertion) force, thereby reducing the lumen's original rest diameter d. r can be made to recover.

[0112] In some embodiments, each segment of the sheath locally contracts after removal of the radially outward force, thereby reducing the lumen's original rest diameter d r The axial direction of the sine wave can be at least partially returned to the axial direction.

[0113] Additionally, additional sheath 8 configurations are disclosed that may be utilized with a delivery apparatus 10 such as that shown in FIG. 1 for delivery of a prosthetic device 12 .

[0114] For example, without limitation, FIGS. 21A-21B illustrate one exemplary embodiment of a sheath disclosed herein. In such an embodiment, the sheath comprises a proximal end and a distal end. The sheath 2100 can comprise a variable diameter inner liner 2102 comprising a sheet having a first edge 2104 and a second edge 2106, defined by an inner surface 2102a and an outer surface 2102b. When the sheet is wound in a spiral configuration, at least a portion of the inner surface 2102a of the sheet overlaps at least a portion of the outer surface 2102b of the sheet. As can be seen in FIGS. 21A-21B, the first edge 2104 of the sheet is slidable along at least a portion of the inner surface 2102a of the sheet, and the second edge 2106 is slidable along at least a portion of the outer surface 2102b of the sheet. The sheath further comprises an outer layer 2108 having an inner surface 2108a and an outer surface 2108b.

[0115] The inner surface 2102a of the sheet further defines a sheath lumen through which a delivery device can be advanced into a patient's vasculature to deliver, remove, repair, and / or replace the prosthetic device. The disclosed sheaths may also be useful for other types of minimally invasive procedures, such as any procedure requiring the introduction of a device into a subject's vasculature. For example, the disclosed sheaths may also be used to introduce other types of delivery devices for placing various types of endoluminal devices (e.g., stents, stent grafts, etc.) into many types of vascular and non-vascular body lumens (veins, arteries, esophagus, ducts of the biliary tree, intestines, urethra, fallopian tubes, other endocrine or exocrine ducts, etc.).

[0116] It is further understood that the sheath can include additional layers, which are disclosed in detail above or below. For example, as disclosed in some exemplary embodiments above, the sheath can include a braid or coil disposed between the inner liner and the outer layer and / or a braid or coil embedded in the outer layer.

[0117] In the exemplary embodiment shown in Figures 21A-21B, the sheath does not include a braid or coil disposed along the length of the sheath between the inner liner and the outer layer or embedded in the outer layer.

[0118] As with other embodiments of sheaths, the exemplary sheath of Figures 21A-21B can have a variety of inner liners depending on the desired application and the size of the delivery apparatus and prosthetic device. Furthermore, it is understood that the inner liner is not limited to a particular shape or configuration. In certain embodiments, the sheaths disclosed herein can have a rest diameter d r and outer diameter d0. As disclosed herein, the rest diameter dr is defined by the inner liner, while the outer diameter can be defined by the inner liner and the outer layer.

[0119] Rest diameter d of inner liner 2102 r can vary depending on the application and size of the delivery apparatus and prosthetic device. The sheaths disclosed herein can have configurations similar to those shown in Figures 3A-3C and described above. In some embodiments, as shown in Figure 3B, the rest diameter d r1 It will be appreciated that the rest diameter d is substantially uniform along the longitudinal axis of the lumen without variation from the proximal end 308 to the distal end 306. In yet another embodiment, as shown in Figures 3A and 3C, the rest diameter d r can vary along the longitudinal axis of the lumen (e.g., d in FIG. 3A). r1 and d r2 , or d shown in Figure 3C r1 , d r2 , d r3 , and d r4 In certain embodiments, the rest diameter d at the proximal end 304 or 312 r1 is located at the distal end 302 or 310d r As shown in Figure 3A, the rest diameter d r2 or d as shown in Figure 3C r4In yet other embodiments, when the outer layer conforms to the shape of the inner liner, the outer diameter d0 (not shown) includes the overall diameter of the inner liner and outer layer. In such embodiments, the outer diameter d0 is defined depending on the particular application of the sheath. r Similarly, the outer diameter d0 of the non-use sheath disclosed herein can be substantially uniform (constant) along the longitudinal axis of the lumen without varying from the proximal end to the distal end (not shown). In an alternative embodiment, the original unexpanded outer diameter d0 of the disclosed sheath can be substantially uniform (constant) along the longitudinal axis of the lumen without varying from the proximal end to the distal end (not shown). r In some embodiments, the rest diameter d r Similarly, the original unexpanded outer diameter may decrease along a gradient from the proximal end to the distal end, or may gradually step down along the length of the sheath, with the largest original unexpanded outer diameter d0 near the proximal end and the smallest original unexpanded outer diameter d0 near the distal end.

[0120] In some embodiments, as with other sheath configurations disclosed herein, the sheath rest diameter d as shown in FIGS. 21A-21B may be adjusted to accommodate the sheath rest diameter d. r may also range from about 0.005 inches to about 0.400 inches, including exemplary values ​​of about 0.01, about 0.02, about 0.03, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09, about 0.1, about 0.2, and about 0.3 inches. As noted above, in certain embodiments, the sheath may be configured with various d r In such an embodiment, the inner liner may include r can have any value between any two of the above values ​​and may depend on the particular application and size and shape of the delivery device and prosthetic device. Depending on the size requirements of the delivery device for different applications, different sheaths may have different expanded and unexpanded rest diameters d r and outer diameter d0. Additionally, some embodiments may provide for greater or lesser expansion depending on the particular design parameters, materials, and / or configurations used.

[0121] 22A-22B illustrate the expansion process of an exemplary sheath, such as that shown in FIGS. 21A-21B. The sheath 2202 can be expanded from a collapsed configuration to an expanded configuration 2204, as shown in FIG. 22A, during passage of a medical device by sliding the first and second longitudinal edges along one another, reducing the overlap of the helical configuration. Again, the expanded diameter d e may depend on the diameter of the medical device being passed. In yet other embodiments, as discussed in more detail below, the outer layer applies an inward radial force to the inner liner to reduce d after the medical device has passed through the lumen. r 22B shows snapshots of sheath expansion at various moments during passage of an exemplary medical device.

[0122] Additional sheath embodiments are disclosed in FIGS. 24A-24B. For example, FIG. 24A shows an inner liner of a sheath having a configuration similar to that of the sheath disclosed in FIG. 22, in which the first end 2404 and the second end 2406 are substantially aligned in a spaced-apart relationship along a vertical axis 2420 passing through the thickness of the sheath. In such a configuration, a portion of the sheet 2403 is disposed between the first and second edges along the vertical axis. As can be seen in FIG. 24A, when the inner liner 2402 is in an unexpanded resting state, the inner liner includes at least two layers of sheeting that overlap each other around at least a portion of the circumference of the sheath. Additionally, as seen in FIG. 24, the inner liner can include at least two layers of sheeting that overlap each other along the entire circumference of the sheath.

[0123] 24B shows different configurations of the liner in an expanded state. For example, when the liner 2402 is in an unexpanded rest state, the inner liner can include a portion along the periphery of a sheath that can have three layers of sheet 2430.

[0124] 22A, for example, some inner liner configurations have a first edge 2204 that is substantially aligned with a vertical axis 2420 that passes through the thickness of the sheath, and a second edge 2406 that is circumferentially offset from the vertical axis. In such embodiments, around at least a portion of the circumference of the sheath, the inner liner comprises one layer of sheet with no overlapping portions.

[0125] Yet an additional configuration of an inner liner is shown in Figure 18. Figure 18 shows an inner liner 1800 comprising a sheet wound into a spiral configuration, the sheet comprising a first portion 1802 having a first surface 1802a and an opposite second surface 1802, a first end 1804 of the first portion 1802 divided into a first segment 1806 having a first surface 1806a and an opposite second surface 1806b and a third segment 1808 having a first surface 1808a and an opposite second surface 1808b, and a second end of the first portion extending into a second segment 1810 having a first surface 1810a and an opposite second surface 1810b.

[0126] 18 , in the spiral configuration, at least a portion of the first surface 1810 a of the second segment 1810 overlaps with at least a portion of the second surface 1806 b of the first segment 1806, at least a portion of the first surface 1808 a of the third segment 1808 overlaps with at least a portion of the second surface 1810 b of the second segment 1810, and at least a portion of the first surface 1808 a of the third segment overlaps with at least a portion of the second surface 1806 b of the first segment 1806. It can also be seen that the first surface 1804 a of the first portion 1804 extends into the first surface 1806 a of the first segment 1806, the first surface 1810 a of the second segment 1810, and the first surface 1808 a of the third segment 1808. It can also be seen that the second surface 1804b of the first portion 1804 extends into the second surface 1810b of the second segment 1810 and into the second surface 1808b of the third segment 1808. Each of these segments can slide along one another during passage of a medical device, expanding the sheath.

[0127] FIG. 19 shows an exemplary sheath having an inner liner 1800 as shown in FIG. 18 and an outer layer 1900.

[0128] Referring back to FIG. 18 , when at least a portion of the first surface 1810a of the second segment 1810 overlaps with at least a portion of the second surface 1806b of the first segment 1806, a first gap 1812 is formed between at least a portion of the first surface 1810a of the second segment 1810 and at least a portion of the second surface 1804b of the first segment 1806.

[0129] Furthermore, a second gap 1814 can be formed when at least a portion of the first surface 1808a of the third segment 1808 overlaps with at least a portion of the second surface 1810b of the second segment 1810. Furthermore, a third gap 1816 can be formed when at least a portion of the first surface 1808a of the third segment 1808 overlaps with at least a portion of the second surface 1806b of the first segment 1806.

[0130] It is understood that the first gap may have a substantially uniform width along the overlapping portion, or its width may vary. Similarly, the second gap may have a substantially uniform width along the overlapping portion, or the width of the second gap may vary along the overlapping portion. Furthermore, the third gap may have a substantially uniform width or a varying width along the overlapping portion. In still other embodiments, the width between the gaps may be any width as desired. For example, it is understood that the widths of each of the three gaps may be the same or different. In certain embodiments, the widths of some of the gaps are the same, while the widths of others are different.

[0131] When a sheath such as that disclosed in Figures 18 and 19 is utilized, the first segment 1806, the second segment 1810, and the third segment 1808 are configured to slide along one another as the medical device passes through the lumen, thereby reducing the overlap between the first and second segments and the overlap between the second and third segments, while increasing the overlap between the first and third segments.

[0132] As with any sheath configuration disclosed herein, the lumen diameter of the sheath shown in FIG. 19 is a first rest diameter d r to the second expansion diameter d eAfter the medical device passes through the lumen, the first segment 1806, the second segment 1810, and the third segment 1808 are configured to slide along one another in opposite directions, thus increasing the overlap between the first and second segments, the second and third segments, and the first and third segments. After passage of the device, the diameter of the lumen increases to a second expanded diameter d e to the first rest diameter d r The diameter of the slit is reduced to substantially the same as that of the slit.

[0133] Furthermore, d as disclosed above r It is understood that the d may be uniform along the length of the sheath, as shown in Figures 3A-3C, or may vary from the proximal end of the sheath to the distal end of the sheath. r It will be understood that any value of is also applicable to sheath configurations such as those shown in FIGS.

[0134] During a transcatheter aortic valve replacement (TAVR) procedure, a sheath such as that disclosed herein is used to provide access to the vascular system without trauma to the patient, maintaining hemostasis and facilitating the delivery of interventional devices and wire and catheter exchanges. To make the sheath as minimally invasive as possible, the sheath must have a low profile or small outer diameter (OD) upon entry. However, the sheath must expand to a larger diameter inside the body to allow the passage of a catheter larger than the initial diameter of the sheath. The force used to advance these devices through the sheath is commonly referred to as the push force. For relatively large devices, such as crimp valves in delivery systems (DSs), and for small, tortuous, or stenosed vessels, the push force during the procedure is crucial. High push forces can cause delays, physician dissatisfaction, and even incomplete procedures.

[0135] Therefore, a key function of the sheath is to have a clinically acceptable pushing force to advance the delivery system and valve through the sheath for all patient anatomies. In some embodiments, lubrication is used to help reduce this pushing force. The lubrication is placed between the sliding layers and reduces the frictional forces that must be overcome to expand the sheath, making it easier for the DS to pass through the sheath. Recent studies have shown that lubrication is required to reduce the pushing force to an acceptable level.

[0136] Furthermore, sheath configurations as disclosed herein can include a lubricant. One exemplary embodiment of a sheath 2300 is shown in FIG. 23. In this configuration, for example, a lubricant 2306 can be disposed between the inner liner 2302 and the outer layer 2304.

[0137] For sheaths having the configurations shown in Figures 18 and 19, lubricant may be disposed in any amount and in any combination between any portions and segments. In certain exemplary, non-limiting embodiments, lubricant may be disposed between the first and second segments, or between the second and third segments, or between the first and third segments, or any combination thereof. In still other embodiments, lubricant may be disposed so as to be located on the innermost surface of the sheath, the outermost surface of the sheath, or a combination thereof.

[0138] In yet another aspect, the lubricant may be disposed along the entire circumference of the inner liner or between at least a portion of the overlapping portion of the sheet and at least a portion of the sliding portion of the sheet.

[0139] Furthermore, the lubricant may be disposed along at least a portion of the inner surface of the sheet, at least a portion of the outer surface of the sheet, or a combination thereof.

[0140] Any lubricant known in the art may be utilized. In yet other embodiments, the lubricant may include a PTFE-based lubricant or a silicone-based lubricant. In certain non-limiting embodiments, the lubricant may include Christo Lube supplied by ECL, or MED10 / 6670 or PRO-3499 supplied by Nusil, or PRO-3595 also supplied by Nusil. In still other embodiments, it is understood that the amount of the first and / or second lubricant may be readily determined by one skilled in the art.

[0141] In further particular embodiments, the lubricant may be disposed in a predetermined pattern, for example, as shown in Figure 26. In such embodiments, the lubricant is disposed in pattern 2609, for example, on inner liner 2602. It will be understood that pattern 2609 is merely exemplary, and that any desired pattern for any particular application may be applied.

[0142] The lubricant can be applied in any manner, for example, it can be applied manually. Because the lubricant is applied manually to the sheath, it can be difficult to precisely control the amount of lubricant added to the sheath and the exact location where the lubricant is applied to the sheath.

[0143] As such, lubricants as disclosed herein can also be applied by pad printing or spraying, resulting in materials that are applied in a precisely controlled and reproducible manner suitable for large-scale manufacturing. Detailed methods of lubricant application are discussed below.

[0144] However, in embodiments in which the lubricant is applied by pad printing, it is understood that the lubricant, prior to application, has a viscosity of about 600 to about 1,200 cP, including exemplary values ​​of about 650 cP, about 700 cP, about 750 cP, about 800 cP, about 850 cP, about 900 cP, about 950 cP, about 1,000 cP, about 1,050 cP, about 1,100 cP, and about 1,150 cP.

[0145] In embodiments in which the lubricant is sprayed, the lubricant can have a viscosity of about 600 cP or less, about 550 cP, about 500 cP, about 450 cP, about 400 cP, about 350 cP, or about 350 cP or less.

[0146] In yet another embodiment, the lubricant is cured prior to placing the outer layer on the inner liner of the sheath.

[0147] The lubricant may also form a film. When a film of the lubricant is formed, such film can have a thickness of about 20 μm or less, about 15 μm, about 10 μm, about 5 μm, about 1 μm, or even about 0.5 μm or less.

[0148] In yet other aspects, the inner liner of any of the configurations disclosed herein can include a polyolefin, a polyamide, a fluoropolymer, a copolymer thereof, or a mixture thereof. In yet other aspects, the polyolefin can include high density polyethylene, polypropylene, or a mixture thereof.

[0149] In still other embodiments, the sheet can comprise one or more layers. In still other embodiments, the sheet can have a multi-layer structure. In some embodiments, when one or more layers are present, each layer can comprise the same or different polymers. In still other embodiments, the sheet can have a predetermined thickness, which can be defined by one of ordinary skill in the art depending on the particular application. In certain embodiments, the predetermined thickness of the inner liner can be from about 0.002 inches to about 0.025 inches, including exemplary values ​​of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, about 0.01, about 0.015, and about 0.02 inches. Furthermore, it is understood that the predetermined thickness of the sheet forming the inner liner of any of the configurations disclosed herein can vary depending on the desired amount of radial expansion as well as the required strength.

[0150] In certain embodiments, any inner liner of the sheath configurations described herein can include a composite material. For example, the polymer layer of the sheet used to form the inner liner can include a composite material including a polyolefin and a lubricious filler. It is understood that any of the aforementioned polyolefins can be used. In some exemplary embodiments, the polyolefin used in the composite material is high-density polyethylene. In still other embodiments, the lubricious filler can be any filler that can improve the lubricity of the polymer layer and reduce the overall coefficient of friction of the liner. In some exemplary, non-limiting embodiments, the lubricious filler can include any additive known to reduce friction and act as a lubricant. In such exemplary, non-limiting embodiments, the lubricious filler can include one or more of graphene, reduced graphene oxide, carbon black, boron nitride, silicone, talc, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene, and the like. In still other embodiments, the lubricious filler includes a PTFE filler. In still other embodiments, the PTFE filler is a powder.

[0151] In still other embodiments, the lubricious filler can be present in any amount. In some exemplary, non-limiting embodiments, the lubricious filler can be present in an amount of about 5 wt% to about 20 wt% of the total weight of the composite material used to make the polymeric layer of the inner liner. In still other embodiments, the lubricious filler can be present in exemplary amounts of about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt%, or about 20 wt%.

[0152] In still other embodiments, sheets comprising such composite materials are lubricious and can have a coefficient of friction of less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, less than about 0.1, or less than about 0.05, or even less than about 0.01. Furthermore, it is understood that the sheet can have a coefficient of friction having any value between any two of the above values.

[0153] It is further understood that when the polymer layer of the sheet used to form the inner liner comprises the composite material disclosed herein, the sheath can be substantially free of a separately disposed lubricant. For example, if the inner liner itself comprises a lubricating filler, a lubricant as disclosed above applied between overlapping portions of the inner liner or between the outermost surface of the inner liner and the innermost surface of the outer layer may not be required. However, also disclosed herein are sheath embodiments in which the inner liner includes a lubricating compound in its composition, and a separate lubricant as disclosed above is still applied between various portions of the sheath. In such exemplary embodiments, this additional lubricant, applied manually, pad-printed, or sprayed, can be applied between some portions of the inner liner and the outer layer, or between all portions of the inner liner and the outer layer, as disclosed above. It is also understood that this additional lubricant can be applied in any desired pattern. The lubricant can also be applied along the entire length of the sheath or only to some portions of the sheath. The lubricant can also be applied in different patterns to different portions of the sheath. In still other embodiments, the lubricant can be applied in the same pattern along various portions of the sheath.

[0154] In yet other embodiments, the inner surface of the sheet may be at least partially ribbed. In such exemplary embodiments, the inner surface of the sheet may be at least partially ribbed prior to winding the sheet into a spiral configuration to form the inner liner.

[0155] In some embodiments, sheaths described herein that include a lubricious material in the inner liner can exert a pushing force required to move a prosthetic device through the sheath that is equal to or less than the pushing force of a substantially identical reference sheath wound in a spiral configuration, the inner liner of which comprises a polymer layer that is substantially free of lubricious fillers and includes an amount of lubricious material disposed between overlapping portions of the spiral configuration and / or the outermost surface of the inner liner. In other words, in some embodiments, when the performance of any of the sheath configurations disclosed herein is compared, in such exemplary, non-limiting embodiments, a sheath that has a lubricious material in the inner liner and no additional lubrication can exhibit similar or better performance than a similar sheath that does not have a lubricious material in the inner liner but has additional lubrication dispersed between various portions of the sheath.

[0156] In still other embodiments, the sheath can also include a tie layer, as described herein. In such embodiments, the tie layer can be disposed on the inner surface of the inner liner or the outer surface of the inner liner, for example, with reference to FIGS. 25A-25B. FIGS. 25A-25B illustrate exemplary coextruded tubing that can be used to form a sheet that will be wound into a spiral configuration. Details of how to form the inner liner are discussed in more detail below. Here, FIGS. 25A-25B illustrate coextruded tubing 2502 including a polymer layer 2505 and a tie layer 2503. FIG. 25A illustrates that tie layer 2503 is coextruded with polymer layer 2505 such that the tie layer is positioned on the outer surface of the polymer layer. It will be understood that the outer surface of the polymer layer defines at least a portion of the outer surface of the inner liner when it is in the spiral configuration. FIG. 25B illustrates that tie layer 2503 is coextruded with polymer layer 2505 such that the tie layer is positioned on the inner surface of the polymer layer. It is understood that the inner surface of the polymeric layer defines at least a portion of the inner surface of the inner liner when it is in a spiral configuration.

[0157] It is understood that polymer layer 2505 can be any of the polymer layers described above that can be used to make the sheet. In certain embodiments, the polymer layer can be high density polyethylene.

[0158] In still other embodiments, the tie layer 2503 can comprise any material suitable for the desired application. It is understood that the tie layer can have adhesive or bonding properties. In certain embodiments, the tie layer can comprise a polyurethane material such as Tecoflex, or a polymer, copolymer, or terpolymer such as a maleic anhydride modified polyolefin, for example, but not limited to, an ethylene acrylic acid copolymer such as Orevac® (available from Arkema), DOW Chemical Primacor®, an ethylene acrylate copolymer such as Lotryl® (available from Arkema), an ethylene glycol methacrylate copolymer, an ethylene acrylic acid ester glycidyl methacrylate terpolymer such as Lotader® (available from Arkema), or an ethylene acrylic acid ester maleic anhydride terpolymer such as Lotader® or Orevac® (available from Arkema).

[0159] In certain embodiments, the total thickness of the sheet including the polymer layer and tie layer can be from about 0.002 inches to about 0.025 inches, including exemplary values ​​of about 0.003, about 0.004, about 0.005, about 0.006, about 0.007, about 0.008, about 0.009, about 0.01, about 0.015, and about 0.02 inches. Furthermore, it is understood that the total thickness of the sheet forming the inner liner of any of the configurations disclosed herein can be varied depending on the desired amount of radial expansion as well as the strength required.

[0160] In still other embodiments, the tie layer can have a thickness of about 0.001" to about 0.003", including exemplary values ​​of about 0.0011", about 0.0012", about 0.0013", about 0.0014", about 0.0015", about 0.0016", about 0.0017", about 0.0018", 0.0019", about 0.0020", about 0.0021", about 0.0022", about 0.0023", about 0.0024", about 0.0025", about 0.0026", about 0.0027", about 0.0028", and about 0.0029".

[0161] In still other embodiments, any of the sheath configurations disclosed herein can have at least one lubricious liner, for example, as shown in Figures 25C-25D.

[0162] 25C-25D show an exemplary coextruded tubing comprising a tie layer 2503 and a polymer layer 2505 and the lubricious liner 2507 disclosed above. This tubing can be used to form a sheet that will be wound into a spiral configuration. Details of how to form the inner liner are discussed in more detail below. As can be seen, the lubricious liner 2507 is disposed on the tie layer 2503. It will be understood that in one configuration, the tie layer and lubricious liner are disposed on the outer surface of the polymer layer (FIG. 25C) or the inner surface of the polymer layer (FIG. 25D). In yet other embodiments, the lubricious liner is bonded to the polymer layer of the sheet by the tie layer.

[0163] 25E-25H show various configurations of sheet 2502 in a spiral configuration when the sheet comprises polymer layer 2505, tie layer 2503, and lubricious liner 2507. FIG.

[0164] The lubricious liner can comprise any material capable of reducing the coefficient of friction of the sheath. In some exemplary, non-limiting embodiments, the lubricious liner can comprise PTFE, polyether block amide, silicone-based liner, perfluoroalkoxyalkane-based liner, e-PTFE, ethylene tetrafluoroethylene, etc. In yet other embodiments, the lubricious liner comprises PTFE.

[0165] In still other aspects, the total thickness of the sheath can be any thickness as disclosed above.

[0166] In still other embodiments, the at least one lubricious liner has a thickness of approximately 0.0011", approximately 0.0012", approximately 0.0013", approximately 0.0014", approximately 0.0015", approximately 0.0016", approximately 0.0017", approximately 0.0018", 0.0019", approximately 0.0020", approximately 0.0021", approximately 0.0022", approximately 0.0023", approximately 0.0024", approximately 0.0025", approximately 0.0026", approximately 0.0027", approximately 0.0028", approximately 0.0029", approximately 0.0030", approximately 0.0031", approximately 0.0032", approximately 0.0033", approximately 0.0034", approximately 0.0035", approximately 0.0036", approximately 0.0037", approximately 0.0038", approximately 0.0039", approximately 0.0040", approximately 0.0041", approximately 0.0042", approximately 0.0043", approximately 0.0044", approximately 0.0045", approximately 0.0046", approximately 0.0047", approximately 0.0048", approximately 0.0049", approximately 0.0050", approximately 0.0051", approximately 0.0052", approximately 0.0053", approximately 0.0054", approximately 0.0055", approximately 0.0056", approximately 0.0057", approximately 0.0058", approximately 0.0059", approximately 0.0060", approximately 0.0061", approximately 0.0062", approximately 0.0063", approximately 0.0064", approximately 0.0065 and about 0.0049".

[0167] In still other embodiments, the lubricious liner may be further ribbed. It is understood that embodiments are also disclosed that include additional lubricant added separately from the lubricious liner. In such embodiments, the additional lubricant may be deposited by any of the methods disclosed herein. It may be manually deposited, pad printed, or sprayed. It is further understood that this additional lubricant, when present, may be deposited in any of the predetermined patterns disclosed herein along a portion of the sheath length or along the entire length of the sheath. In still other embodiments, when a lubricant layer as described herein is present, no additional lubricant is present.

[0168] In still other embodiments, the outer layer of any one sheath configuration can include a styrenic elastomer, a polyurethane, a latex, a copolymer thereof, a blend thereof, or a coextrusion thereof. In certain non-limiting embodiments, the polymer can include a polyether block ester copolymer, a polyester, a polyvinyl chloride, a thermoset silicone, a polyisoprene rubber, a polyolefin, another medical grade polymer, or a combination thereof.

[0169] In still other embodiments, the outer layer can comprise one or more layers. In some embodiments, at least one layer comprises a styrenic elastomer. In still other embodiments, at least one layer comprises a polyurethane. In other embodiments, at least one layer comprises a blend of a styrenic elastomer and a polyurethane.

[0170] It is understood that the hardness of each layer of the disclosed sheaths may also vary depending on the particular application and desired properties of the sheath. In some embodiments, the outer layer has a Shore A durometer of between 20A and 50A, with exemplary values ​​of about 25A, about 30A, about 35A, about 40A, and about 45A.

[0171] In still other embodiments, the polymeric layer of the outer layer can have a Shore hardness of less than 90 durometer, less than 80 durometer, less than 70 durometer, less than 60 durometer, less than 50 durometer, less than 40 durometer, 30 durometer, or less than 20 durometer. In still other exemplary embodiments, the polymeric layer of the outer layer can have a Shore hardness of from about 25 durometer to about 75 durometer, including exemplary values ​​of about 30 durometer, about 35 durometer, about 40 durometer, about 45 durometer, about 50 durometer, about 55 durometer, about 60 durometer, about 65 durometer, and about 70 durometer.

[0172] A sheath as shown in any of the foregoing configurations can also have an outer layer including a first polymer layer, the first polymer layer including a first composite composition, the first composite composition including greater than 0 wt % to less than 100 wt % of a polymer including a polyether block amide, a polyurethane, or a combination thereof, less than about 65% inorganic filler based on the total weight of the first composite composition, and up to about 20% solid lubricant filler based on the total weight of the first composite composition. However, it is understood that in some embodiments, the disclosed sheath can include additional components. These exemplary embodiments are disclosed herein, as set forth in detail below.

[0173] In certain embodiments, the outer layer comprises a first polymer layer. In such exemplary embodiments, the first polymer layer can comprise a first composite composition comprising from greater than 0 wt% to less than 100 wt% of a polymer comprising a polyether block amide, a polyurethane, or any combination thereof, where greater than 0 wt% to less than 100 wt% includes exemplary values ​​of about 0.01 wt%, about 1 wt%, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 85 wt%, about 90 wt%, about 95 wt%, and about 99.9 wt%.

[0174] In yet other embodiments, the first composite composition can include from greater than about 35 wt % to less than about 80 wt % of a polymer comprising a polyether block amide, a polyurethane, or any combination thereof, with exemplary values ​​of from greater than about 35 wt % to less than about 80 wt % including about 40 wt %, about 45 wt %, about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, and about 75 wt %.

[0175] In certain embodiments, the polymer in the first composite composition comprises a polyether block amide. In one such exemplary embodiment, the polyether block amide may comprise PEBAX® from Arkema. In yet other embodiments, the polymer may comprise a polyurethane, such as NEUSoft®. In yet other embodiments, the polymer may comprise a combination of a polyether block amide, such as PEBAX®, with a polyurethane. When a blend of polymers is present, it is further understood that such a blend may comprise any amount of each component relative to another component to provide the desired polymer that falls within the above disclosed ranges.

[0176] In still other embodiments, the first composite composition can comprise less than about 65 wt% inorganic filler, based on the total weight of the first composite composition, which can include exemplary values ​​of less than about 60 wt%, less than about 55 wt%, less than about 50 wt%, less than about 45 wt%, less than about 40 wt%, less than about 35 wt%, less than about 30 wt%, less than about 25 wt%, less than about 20 wt%, less than about 15 wt%, less than about 10 wt%, about 5 wt%, and less than about 1 wt% inorganic filler.

[0177] In still other embodiments, the inorganic filler can be present in an amount of at least about 1 wt%, at least about 2 wt%, at least about 5 wt%, at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 35 wt%, at least about 40 wt%, at least about 45 wt%, at least about 50 wt%, or at least about 55 wt%.

[0178] In yet other embodiments, the inorganic filler can include any inorganic material that can be used as a filler and is acceptable for the desired application. In certain exemplary, non-limiting embodiments, the inorganic filler can include bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin clay, limestone, or any combination thereof. Again, it is understood that the inorganic filler can include a combination of various fillers. In such exemplary embodiments, the amount of each filler in the combination can be in any range to provide a final combination that falls within the disclosed ranges above.

[0179] In still other embodiments, the first composite composition can include up to about 20% solid lubricant filler, including exemplary values ​​of about 0.01 wt%, about 0.1 wt%, about 0.5 wt%, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt%, and about 19.9 wt%, based on the total weight of the first composite composition. In still other embodiments, the solid lubricant filler can be present at up to about 20 wt%, up to about 15 wt%, or up to about 10 wt%, based on the total weight of the first composite composition.

[0180] In yet other embodiments, the solid lubricant filler can include any additive known to reduce friction and act as a lubricant. In such exemplary, non-limiting embodiments, the solid lubricant filler can include one or more of graphene, reduced graphene oxide, carbon black, boron nitride, silicone, talc, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene, and the like. In yet other embodiments, the solid lubricant includes a PTFE filler. In yet other embodiments, the PTFE filler is a powder.

[0181] In yet another embodiment, the first composite composition can further include at least one tack-reducing compound. Any compound known in the art that can reduce the tack of a polymer composition can be considered and used for the purposes of this disclosure. In yet another exemplary, non-limiting embodiment, the at least one tack-reducing compound includes ProPell™ from Foster Corporation.

[0182] In certain embodiments, the at least one stickiness-reducing compound is present in an amount of 0 wt% to about 20 wt%, based on the total weight of the first composite composition, including exemplary values ​​of about 0.01 wt%, about 0.05 wt%, about 0.1 wt%, about 0.5 wt%, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, and about 19 wt%. In still other embodiments, the at least one stickiness-reducing compound is present in any amount between any two of the above values. For example, but not limited to, the at least one stickiness-reducing compound can be present in an amount of about 1 wt % to about 5 wt % or about 5 wt % to about 10 wt %, based on the total weight of the first composite composition.

[0183] In yet other embodiments, as disclosed herein, the polymer in the first polymer layer composition has substantially the same durometer along the entire length of the outer layer. However, it is understood that the durometer of the polymer in the first polymer layer composition of the outer layer may vary along the length of the outer layer. For example, without limitation, disclosed herein are embodiments in which the durometer of the polymer in the first polymer layer composition at the proximal end of the outer layer is different from the durometer of the polymer in the first polymer layer composition at the distal end of the outer layer.

[0184] In still other embodiments, the polymer in the first polymer layer composition has a Shore D of about 20D to about 72D, including exemplary values ​​of about 25D, about 30D, about 35D, about 40D, about 45D, about 50D, about 55D, about 60D, about 65D, and about 70D. In still other embodiments, the polymer in the first polymer layer composition has a Shore D of about 20D to about 35D. In still other embodiments, the polymer in the first polymer layer composition has a Shore D of about 30D. In still other embodiments, the polymer in the first polymer layer composition has a Shore D of about 25D.

[0185] It is understood that the outer layer may include embodiments in which only one polymer layer is present as disclosed herein. In still other embodiments, two or more polymer layers may be present in the outer layer. In such exemplary embodiments, the outer layer includes at least a second polymer layer comprising a second composite composition comprising from greater than 0 wt% to 100 wt% of a second polymer comprising a polyether block amide, polyurethane, or a composition thereof. As with the first composite composition, the second polymer may be present in any amount within the disclosed ranges. For example, the second polymer can be present in the second composite composition at greater than 0 wt%, about 0.01 wt%, about 1 wt%, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 85 wt%, about 90 wt%, about 95 wt%, and about 99.9 wt% of a polymer comprising a polyether block amide, a polyurethane, or any combination thereof. In still other embodiments, the second polymer can be present in the second composite composition from about 95 wt% to less than about 99 wt%, including exemplary values ​​of about 95.5 wt%, about 96 wt%, 96.5 wt%, about 97 wt%, about 97.5 wt%, about 98 wt%, and about 98.5 wt%.

[0186] In still other embodiments, the second composite composition can further comprise up to 20 wt% of a stickiness-reducing additive, including exemplary values ​​of about 0.01 wt%, about 0.05 wt%, about 0.1 wt%, about 0.5 wt%, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, and about 19 wt%, based on the total weight of the second composite composition. In still other embodiments, the at least one stickiness-reducing compound is present in an amount having a value between any two of the above values. For example, without limitation, the at least one adhesion-reducing compound can be present in an amount of about 1 wt % to about 5 wt % or about 5 wt % to about 10 wt %, based on the total weight of the second composite composition. In yet other embodiments, the second composite composition, as disclosed herein, can be substantially free of solid lubricant fillers.

[0187] It is further understood that in certain embodiments, the first polymer in the first composite composition can be the same as the second polymer in the second composite composition. In yet other embodiments, the first polymer in the first composite composition is different from the second polymer in the second composite composition. In still other embodiments, the second polymer layer composition comprises PEBAX®. In further embodiments, the second polymer layer composition can comprise a polyurethane, such as NEUSoft® from PolyOne.

[0188] In still other embodiments, the second polymer has a Shore D of about 20 D to about 35 D. In still other embodiments, the second polymer has a Shore D of about 25 D or about 35 D.

[0189] In yet other embodiments, the second composite composition can be substantially free of inorganic fillers. In certain embodiments, inorganic fillers can be present in the second composite composition in any amount from greater than 0 wt% to less than 100 wt%, including exemplary values ​​of about 0.01 wt%, about 0.05 wt%, about 0.1 wt%, about 0.5 wt%, about 1 wt%, about 5 wt%, about 10 wt%, about 20 wt%, about 30 wt%, about 40 wt%, about 50 wt%, about 60 wt%, about 70 wt%, about 80 wt%, about 90 wt%, and about 95 wt%. In embodiments in which inorganic fillers are present in the second composite composition, such inorganic fillers can include any filler disclosed above.

[0190] In still other embodiments, as disclosed herein, the outer layer has a predetermined thickness, and at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or 100% of the predetermined thickness comprises first and / or second composite compositions comprising first and / or second polymers having a Shore D of about 30D or less.

[0191] In still other embodiments, the predetermined thickness of the outer layer can vary along the length of the sheath. In other embodiments, the predetermined thickness of the outer layer is the same along the length of the sheath. In still other embodiments, the predetermined thickness of the outer layer is greater at the proximal end. In still other embodiments, the predetermined thickness of the outer layer is up to 0.006", for example, but not limited to, about 0.001" to about 0.006", including exemplary values ​​of about 0.0015", about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", and about 0.006".

[0192] In yet other embodiments, the first polymer layer and the second polymer layer can have the same thickness. In other embodiments, the first polymer layer and the second polymer layer have different thicknesses. For example, in some embodiments, the first polymer layer has a thickness of about 0.01" to about 0.003", including exemplary values ​​of about 0.0011", about 0.0012", about 0.0013", about 0.0014", about 0.0015", about 0.0016", about 0.0017", about 0.0018", about 0.0019", about 0.0020", about 0.0021", about 0.0022", about 0.0023", about 0.0024", about 0.0025", about 0.0026", about 0.0027", about 0.0028", and about 0.0029". In still other embodiments, the second polymer layer has a thickness of about 0.0011", about 0.0012", about 0.0013", approx. 0.0014", approx. 0.0015", approx. 0.0016", approx. 0.0017", approx. 0.0018", approx. 0.0019", approx. 0.0020", approx. 0.0021", approx. 0.0022", approx. 0.0023", approx. 0.0024", approx. 0.0025", approx. 0.0026", approx. 0.0027", approx. The thickness may be from about 0.002" to about 0.004", including about 0.028", about 0.0029", 0.0030", about 0.0031", about 0.0032", about 0.0033", about 0.0034", about 0.0035", about 0.0036", about 0.0037", about 0.0038", and 0.0039".

[0193] In yet other aspects, the predetermined thickness of the outer layer is greater at the proximal end. In other aspects, the predetermined thickness of the outer layer is less at the distal end compared to the predetermined thickness of the outer layer at the proximal end.

[0194] In yet other embodiments in which two or more layers are present in the outer layer, a first polymer layer can define the inner surface of the outer layer, and a second polymer layer can define the outer surface of the outer layer. However, there are also embodiments in which a first polymer layer defines the outer surface of the outer layer, and a second polymer layer defines the inner surface of the outer layer. It is understood that other embodiments are also included in which one or more additional polymer layers are disposed between the first and second polymer layers.

[0195] In still other embodiments, the outer layer may be extruded as a tube, which may then be slid onto the inner liner of the sheath. In embodiments where first and second polymer layers are present, such polymer layers may be coextruded. In still other embodiments, the first polymer layer may be substantially bonded to the second polymer layer. In such exemplary embodiments, the first polymer layer does not substantially delaminate from the second polymer layer. It is understood that in some embodiments, the bond may be physical, chemical, or any other type known in the art.

[0196] In still other aspects, any sheath comprising an outer layer disclosed herein can exhibit an insertion force of less than about 55 N, less than about 50 N, less than about 45 N, less than about 40 N, less than about 35 N, or less than about 35 N when a medical device is pushed through the sheath.

[0197] In still other embodiments, the outer layer may also exhibit a friction force in a dry state against a substrate surface comprising one or more of polytetrafluoroethylene, fluorinated ethylene propylene, or high density polyethylene having a diameter of about 0.300" of less than about 10 N, or less than about 9 N, or less than about 8 N, or less than about 7 N, or less than about 6 N, or even less than about 5 N.

[0198] In still other embodiments, the outer layer extruded as a tube can exhibit a hoop force at 10 mm elongation (about 85% strain) of less than about 10 N, or less than about 9 N, or less than about 8 N, or less than about 7 N, or less than about 6 N, or even less than about 5 N. In such exemplary embodiments, the extruded tube forming the outer layer of the sheath can have a diameter of about 0.290" (7.4 mm) and a wall thickness as disclosed herein. In embodiments in which the outer layer has a diameter of about 0.290" (7.4 mm) and a total wall thickness of about 0.0045", the hoop force at 10 mm elongation can be less than about 8 N for a sample length of about 0.25" (6.4 mm). It is understood that in some exemplary non-limiting embodiments, a low force at 10 mm elongation is desirable for a low sheath expansion force.

[0199] In still other embodiments, the outer layer can exhibit an elongation to break in the range of between about 650% and about 800%, including exemplary values ​​of about 680%, about 700%, about 710%, about 750%, and about 780%. It is understood that in some exemplary, non-limiting embodiments, a higher elongation is preferred so that the outer layer can expand to a larger diameter before breaking.

[0200] In certain embodiments, the outer layer extends along a portion of the length of the sheath. In such exemplary embodiments, the outer layer can be positioned at the proximal end of the sheath, at the center of the sheath, or at the distal portion of the sheath. In other embodiments, the outer layer extends along the entire length of the sheath. In such exemplary embodiments, the outer layer can be positioned at the proximal end of the sheath and extend to the distal end of the sheath.

[0201] In still other embodiments, the outer layer of any one of the sheath configurations disclosed herein can include one or more polymer layers. In some embodiments, the first polymer layer can be the first polymer layer disclosed above. In still other embodiments, the outer layer can also include a second polymer layer, which can be any second polymer layer disclosed above. In some exemplary, non-limiting embodiments, the second polymer layer can include polyurethane. In some exemplary, non-limiting embodiments, the first polymer layer can include PEBAX, as disclosed above, alone or in combination with an inorganic filler and a solid lubricant filler. In still other exemplary, non-limiting embodiments, the second polymer layer can include polyurethane, such as Neusoft.

[0202] In certain embodiments, a first polymer layer, as disclosed above, and a second polymer can be coextruded to form bump tubing. It is understood that bump tubing or tapered tubing generally is used in a variety of applications.

[0203] It will be appreciated that in some aspects, bumped or tapered tubing may be particularly useful for certain catheter applications. Neurovascular and microcatheters typically have a larger proximal diameter to improve pushability of the device and a smaller distal end to improve performance and deliverability.

[0204] In some aspects disclosed herein, the bump tubing forming the outer layer of the sheath can have a predetermined length that is substantially similar to the length of the sheath, while in other aspects, the bump tubing forming the outer layer of the sheath can have a predetermined length that is shorter than the length of the sheath.

[0205] In certain embodiments, the first polymer layer can define the inner surface of the outer layer (bump tubing). In such embodiments, the second polymer layer will define the outer surface of the outer layer.

[0206] In yet other embodiments, it can define the outer surface of the outer layer (bump tubing). In such embodiments, the second polymer layer will define the inner surface of the outer layer.

[0207] In still other embodiments in which the outer layer has the above configuration, the first polymer layer can have a thickness of about 0.001" to about 0.010", including exemplary values ​​of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009", and about 0.0095". The thickness of the first polymer layer in the outer layer can be about 0.001" to about 0.010", including exemplary values ​​of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009", and about 0.0095". It will be appreciated that the thickness of the polymer layer can be uniform along the length of the sheath. In yet other embodiments, the thickness of the first polymer layer in the outer layer can vary along the length of the sheath. In some embodiments, the thickness of the first polymer layer is greater at the proximal end of the sheath compared to the thickness of the first polymer layer along other portions of the sheath. In still other embodiments, the thickness of the first polymer layer at the distal end of the sheath can be less than the thickness of the first polymer layer at the proximal end of the sheath.

[0208] In some embodiments, the second polymer layer, when present in the outer layer, can have a thickness of about 0.001" to about 0.010", including exemplary values ​​of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009", and about 0.0095". It will be appreciated that the thickness of the second polymer layer can be uniform along the length of the sheath. In yet other embodiments, the thickness of the outer polymer layer at the outer layer can vary along the length of the sheath. In some embodiments, the thickness of the second polymer layer is greater at the proximal end of the sheath compared to the thickness of the second polymer layer along other portions of the sheath. In still other embodiments, the thickness of the second polymer layer at the distal end of the sheath can be less than the thickness of the second polymer layer at the proximal end of the sheath.

[0209] In still other embodiments, the first polymer layer can have a Shore D of about 20D to about 72D, including exemplary values ​​of about 25D, about 30D, about 35D, about 40D, about 45D, about 50D, about 55D, about 60D, about 65D, and about 70D. In still other embodiments, the polymer in the first polymer layer composition has a Shore D of about 20D to about 35D. In still other embodiments, the polymer in the first polymer layer composition has a Shore D of about 30D. In still other embodiments, the polymer in the first polymer layer composition has a Shore D of about 25D.

[0210] In still other embodiments, the second polymer layer can have a Shore A of about 30A to about 80A, including exemplary values ​​of about 40A, about 45A, about 50A, about 55A, about 60A, about 65A, about 70A, and about 75A.

[0211] In still other embodiments, the outer layer has a predetermined total thickness, and at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or 100% of the predetermined total thickness comprises a first composite composition comprising a first polymer having a Shore D of about 20D to about 35D as disclosed herein. In still other embodiments, the predetermined total thickness of the outer layer is up to about 0.02", or up to about 0.015", or up to about 0.01", or up to about 0.009", or up to about 0.008", or up to about 0.007", or up to about 0.006".

[0212] In still other aspects, the predetermined total thickness of the outer layer can be uniform along the length of the sheath or can vary along the length of the sheath. In some exemplary non-limiting aspects, the predetermined total thickness of the outer layer is greater at the proximal end of the sheath. In still other aspects, the total thickness of the outer layer at the distal end of the sheath is less than the total thickness of the outer layer at the proximal end of the sheath.

[0213] Also disclosed herein are sheath embodiments in which the outer layer comprises one or more layers that are formed separately. For example, the first and second polymer layers described above are formed separately instead of being coextruded. In such embodiments, the outer layer is formed by placing one of the polymer layers on top of the other.

[0214] In some exemplary, non-limiting embodiments, the second polymer layer can be at least partially disposed on the first polymer layer. Also disclosed are embodiments in which the first polymer layer at least partially overlies the second polymer layer.

[0215] In certain embodiments, when two polymers are formed separately and placed against each other, the polymer layers can each have a different length.

[0216] In some exemplary, non-limiting embodiments, the first polymer layer can have a length that is shorter than the length of the second polymer layer. In some embodiments, the first polymer layer is disposed on the inner liner at the proximal end of the sheath and can have a length of about 5 cm to about 15 cm, with exemplary values ​​of about 6 cm, about 7 cm, about 8 cm, about 9 cm, about 10 cm, about 11 cm, about 12 cm, about 13 cm, and about 14 cm. In still other embodiments, a second polymer layer is then disposed on the first polymer layer. In such embodiments, the second polymer layer can have any length that is compatible with the desired application. In certain embodiments, the second polymer layer can have a length that is substantially the same as the length of the sheath.

[0217] However, it is understood that the reverse configuration of the outer layer is also disclosed. In such embodiments, the second polymer layer may be disposed first on the inner liner and have a length shorter than the length of the sheath. Furthermore, the second polymer layer may be disposed on the second polymer layer. In such exemplary embodiments, the first polymer layer may have any length. In some embodiments, the length of the first polymer layer may be substantially the same as the length of the sheath.

[0218] Furthermore, the first polymer layer as disclosed in these embodiments can have a uniform thickness along the length of the first polymer layer, or it can vary along the length of the first polymer layer. The thickness of the first polymer layer can be any thickness as disclosed above. In some embodiments, the thickness can be anywhere between about 0.001" and about 0.006", including exemplary values ​​of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", and about 0.0055".

[0219] Furthermore, the second polymer layer as disclosed in these embodiments can have a uniform thickness along the length of the second polymer layer, or it can vary along the length of the second polymer layer. The thickness of the first polymer layer can be any thickness as disclosed above. In some embodiments, the thickness can be anywhere between about 0.001" and about 0.010", including exemplary values ​​of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009", and about 0.0095".

[0220] In some exemplary non-limiting embodiments, if the two polymer layers of the outer layer are formed separately, a tie layer may be disposed between the two. Furthermore, it is understood that any of the tie layers disclosed above may be utilized.

[0221] As discussed in detail above, an important function of the sheath is to have a clinically acceptable pushing force for all patient anatomies.

[0222] The various types of lubricants and methods that can be used to reduce pushing forces are disclosed above. As disclosed, any of the disclosed lubricants (lubricous materials, lubricous fillers, lubricous liners) can reduce the frictional forces between the various layers of the sheath that slide against each other, making it easier for the delivery system to open the sheath. However, lubrication between the inner liner and outer layer can cause the outer layer to slide easily over the sheath shaft. If a large portion of the outer layer slides together, the outer layer may bunch up, thereby increasing the outer diameter (OD), a phenomenon known as bunching. This can lead to obstructions to sheath insertion or withdrawal and more traumatic interactions with the vessel.

[0223] In certain aspects, to avoid this problem, the outer layer can be bonded to the inner liner of the expandable sheath in a manner that prevents migration of the outer layer along the sheath shaft.

[0224] In certain embodiments, bonding between the inner liner and outer layer can occur anywhere. In still other embodiments, such bonding can occur in areas of the sheath cross section configured to minimize stretching of the outer layer during expansion. Bonding can also occur in areas where lubrication is not present.

[0225] Accordingly, embodiments are disclosed herein in which at least a portion of the innermost surface of the outer layer is bonded to at least a portion of the outermost surface of the inner liner. Such an exemplary embodiment is also shown in FIG. 27. It is understood that such bonding may optionally be present in any one of the sheath configurations disclosed above. Bonding may be achieved by any method known in the art. In some embodiments, bonding is achieved by laser welding, crimping, and / or selective ultrasonic welding.

[0226] In certain embodiments, bonding of the outer layer to the inner liner can occur in a portion of the sheath cross section where the outer layer is not expected to stretch or move significantly relative to the inner liner during expansion. In yet another exemplary, non-limiting embodiment, the portion of the inner member immediately adjacent the end of the outer layer meets this criterion. As shown in FIG. 27 , the bond 2790 is made between the inner liner 2702 and the outer layer 2708 in a portion where the outer layer is not expected to stretch or move significantly relative to the inner liner. In such an embodiment, no lubricant 2707 is applied to this portion of the inner liner to ensure a good bond between the two components. At this location, the outer layer can be bonded in place along the length of the sheath shaft to prevent longitudinal movement on the inner member. In yet other embodiments, the outer layer can be bonded to the inner liner at a portion of the sheath. Because the bonds disclosed herein do not impede movement of the inner liner relative to the outer layer or the stretching of the outer layer itself, the force required to expand the sheath is not adversely affected by the bond.

[0227] It is understood that in still other embodiments, the bond location may be important to minimize pushing forces. In still other embodiments, the bond covers a relatively small portion of the sheath circumference. In still other embodiments, the method for making the bond must be precisely controlled to ensure repeatability of the process. Specific methods for making the bond are described in detail below.

[0228] In yet other embodiments, two or more portions of the inner liner and outer layer may be bonded together. In such exemplary embodiments, the bond may be formed in a predetermined pattern. In still other embodiments, the bond pattern may be aligned with a lubricant pattern. In such embodiments, the bond may occur in any portion of the sheath where no lubricant is present.

[0229] It is understood that when a sheath is used to deliver a prosthetic device into a patient's blood vessel, hemostasis can be compromised if blood from the patient's arteriotomy penetrates between the inner liner and the outer layer, in such a scenario, the outer layer is the only sheath element resisting blood pressure and maintaining hemostasis.

[0230] The outer layer is typically formed from a material that, on the one hand, allows for easy expansion of the inner liner, while, on the other hand, applies an inward force to the inner liner, causing it to contract back to its original, unexpanded configuration. However, with sufficiently high blood pressure, the outer layer may form a "balloon" that may at some point rupture and compromise hemostasis. A schematic illustration of such a phenomenon is shown in FIGS. 29A-29B. An exemplary sheath 2900 having an inner liner 2902 and an outer layer 2908 and connected to a hub 2911 is inserted into a patient's anatomy 2913. If hemostasis is not maintained, the outer layer may form a "balloon" 2915, potentially causing undesirable effects for the patient.

[0231] For portions of the sheath below the patient's skin level, potential ballooning can be contained by the tissue surrounding the sheath, resisting blood pressure, but for portions of the sheath that are external to the patient, this undesirable phenomenon can still occur. The portion of the sheath that remains external to the patient's body varies and depends on the patient's size and anatomy and physician preference.

[0232] Making the outer layer material stiff enough to resist blood pressure and prevent ballooning can have the undesirable trade-off of increasing the force required to expand the inner liner and therefore increasing the force required to advance the delivery system through the sheath.

[0233] The embodiments described herein address this issue and help prevent excessive outer layer ballooning in the portion of the sheath that remains outside the patient's body while minimizing the impact on the force that expands the sheath.

[0234] The embodiments described herein aim to reinforce the outer layer of the sheath along its proximal portion without significantly affecting its ability to expand while the delivery system is being pushed through the sheath. It is understood that in some embodiments described herein, the reinforced portion of the outer layer can remain entirely outside the patient's arteriotomy. In still other embodiments, at least a portion of the reinforced portion can be inserted into the patient's vessel. Some exemplary schematic diagrams of the disclosed embodiments are shown in FIGS. 29C-29D, in which a reinforced layer 3025 is disposed on the outer layer 2908 to substantially prevent a "ballooning" effect. As shown in FIG. 29D, the reinforced portion of the sheath can have a length sufficient to allow at least a portion of the reinforced portion to be inserted into the patient's anatomy 2913.

[0235] In such embodiments, reinforcement of the outer layer in the proximal portion of the sheath can be achieved by disposing a reinforcing jacket having a proximal end and a distal end over at least a portion of the outer layer. The reinforcing jacket can comprise an elastomeric material and a reinforcing element as disclosed herein. The reinforcing jacket is positioned in the proximal portion of the outer layer. In such embodiments, the end of the reinforcing jacket is substantially seamlessly bonded to at least a portion of the outer surface of the outer layer. This smooth transition between the outer layer and the reinforcing jacket allows the sheath to be inserted into a patient.

[0236] In yet other embodiments, the proximal end of the reinforcing jacket may be bonded to the proximal end of the outer layer, although embodiments are also disclosed in which the proximal end of the reinforcing jacket is not bonded to the proximal end of the outer layer.

[0237] In certain embodiments, the reinforcing jacket can have a length of about 5 cm to about 15 cm, including exemplary values ​​of about 6 cm, about 7 cm, about 8 cm, about 9 cm, about 10 cm, about 11 cm, about 12 cm, about 13 cm, and about 14 cm.

[0238] In yet other aspects, the elastomeric material present in the reinforcing jacket can be any elastomer known in the art. In some aspects, the elastomeric material includes polyether block amides, styrenic elastomers, polyurethanes, latexes, copolymers thereof, blends thereof, or coextrusions thereof. In still other aspects, the elastomer can include a silicone-based elastomer.

[0239] In still other embodiments, the elastomeric material can have a Shore hardness of about 10A to about 80A, including exemplary values ​​of about 20A, about 25A, about 30A, about 35A, about 40A, about 45A, about 50A, about 55A, about 60A, about 65A, about 70A, and about 75A.

[0240] In yet other embodiments, the reinforcing jacket includes reinforcing elements. Several exemplary schematic diagrams of various reinforcing jackets are shown in FIGS. 30A-30B. The reinforcing jacket 3025 is seamlessly bonded at the distal end of the reinforcing jacket to the outer layer 3008 disposed on the inner liner 3002. The proximal end of the reinforcing jacket may or may not be bonded to the inner liner and / or hub 3011. Reinforcing filaments 3027 are disposed within the elastomer. The reinforcing elements expand to a certain diameter where their resistance increases dramatically, with minimal impact on the resistance of the outer layer.

[0241] As the delivery system is pushed through the sheath, it only requires a limited amount of expansion to accommodate the OD of the crimped valve. This limited expansion does not engage the reinforcing elements, so up to this point the sheath expansion force is minimally affected, solely by the low durometer elastomer. If ballooning begins, the diameter of the outer and reinforcing layers only increases until the reinforcing elements are activated, preventing excessive ballooning.

[0242] In certain aspects, the reinforcing element can include a plurality of filaments arranged in a braided configuration. In such aspects, the plurality of filaments can be arranged in a plurality of circumferential rows within the reinforcing jacket, each of the plurality having a sinusoidal shape or any irregular shape, or any combination thereof. In certain aspects, the braid or coil can be an expandable braid or coil.

[0243] In still other embodiments, the plurality of filaments can comprise stainless steel, nitinol, a polymeric material, or a composite material. In certain non-limiting embodiments, the filaments can comprise nitinol and / or other shape memory alloys. In still other non-limiting embodiments, the filaments can comprise polyester or nylon. In yet some other exemplary embodiments, the filaments can comprise Spectra fibers, polyethylene fibers, aramid fibers, or combinations thereof.

[0244] Some exemplary embodiments of braid or coil configurations are shown in FIG. 4. In certain embodiments, the braid or coil may be a generally thin, hollow, substantially cylindrical tube containing an arrangement, pattern, structure, or configuration of filaments or struts, although other shapes may be used. Suitable filaments may be circular and have a diameter of less than about 0.015", less than about 0.01", less than about 0.008", less than about 0.005", less than about 0.002", less than about 0.001", less than about 0.0008", or less than about 0.0005". In still other embodiments, suitable filaments are circular and may range from about 0.0005" inches thick to about 0.015" thick, including exemplary values ​​of about 0.0006", about 0.0007", about 0.0008", about 0.0009", about 0.001", about 0.002", about 0.003", about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014". In still other embodiments, suitable filaments may range from about 0.0005" inches thick to about 0.015" thick, including exemplary values ​​of about 0.0006", about 0.005", about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014". The flat filaments can have heights of less than 3", less than about 0.001", less than about 0.0009", less than about 0.0008", less than about 0.0007", less than about 0.0006", and about 0.0005". In still other embodiments, the flat filaments can have widths of greater than about 0.003" to about 0.015", including exemplary values ​​of about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014". However, other shapes and sizes are also suitable in certain embodiments.

[0245] In still other embodiments, the braid may have fewer than 50, fewer than 40, fewer than 30, fewer than 20, or fewer than 10 crossovers per inch (PIC). In still other embodiments, the braid may have a PIC number of 10 to 2, with exemplary values ​​of 9, 8, 7, 6, 5, 4, and 3. In still other embodiments, the PIC may vary along the longitudinal axis of the lumen. In still other embodiments, the braid pattern may vary along the longitudinal axis of the lumen. In embodiments where the braid or coil includes filaments that are nitinol, the nitinol may have an expanded diameter d e In yet other embodiments, when the filaments comprise stainless steel or nitinol, the filaments are configured to be atraumatic at least at the distal end of the sheath. FIGS. 4A-4D show partial elevational views of various configurations of the braid or coil 28. It is understood that the configuration of the braid or coil 28 may vary from section to section along the length of the sheath. Furthermore, it is understood that the configurations shown in FIGS. 4A-4D are not necessarily drawn to scale and represent merely exemplary, non-limiting embodiments. It is further understood that the braid is configured to provide torque transmission for the sheath during insertion of the prosthetic device.

[0246] In yet another embodiment, the reinforcing element may include wires arranged in multiple circumferential rows embedded within the elastomeric material. In such an embodiment, the wires may have any shape configured to expand or contract. For example, the wires may have a sinusoidal or wave-like shape. The phase and amplitude of the wires may vary depending on the desired application. It is understood that the frequency and total number of circumferential rows present in the elastomeric material may also vary depending on the desired application. The expansion of the wires allows the outer layer of the sheath to continue expanding until the reinforcing element present in the elastomeric material tightens. In this configuration, the reinforcing jacket stops further expansion, thus maintaining hemostasis.

[0247] In yet another aspect, the tie layer may be disposed between the reinforcing jacket and the outer layer of the sheath.

[0248] Additional configurations of the reinforcing jacket are also disclosed. In this embodiment, the outer layer does not extend to the proximal end of the sheath, and at least a portion of the inner liner at the proximal end of the sheath is substantially free of the outer layer. This proximal portion of the sheath not covered by the outer layer can be any length. In some embodiments, this proximal portion is from about 5 cm to about 15 cm, with exemplary values ​​being about 6 cm, about 7 cm, about 8 cm, about 9 cm, about 10 cm, about 11 cm, about 12 cm, about 13 cm, and about 14 cm.

[0249] The proximal portion of such an outer layer may be bonded to the inner liner to ensure that no gap exists between the inner liner and the outer layer when the sheath is inserted into a patient. This bond may also prevent the outer layer from slipping off when the sheath is inserted into a patient. In such an embodiment, a reinforcing jacket having a proximal end and a distal end is positioned on at least a portion of the outer surface of the inner liner at the proximal end of the sheath, which is substantially free of the outer layer. In such a configuration, it is understood that the proximal end of the reinforcing jacket abuts the proximal end of the sheath and is at least partially bonded to at least a portion of the proximal end of the outer surface of the inner liner.

[0250] Again, the reinforcing jacket can have a length substantially similar to the length of the proximal portion of the sheath without the outer layer. In some exemplary non-limiting embodiments, the length of the reinforcing jacket can be from about 5 to about 15 cm, including exemplary values ​​of about 6 cm, about 7 cm, about 8 cm, about 9 cm, about 10 cm, about 11 cm, about 12 cm, about 13 cm, and about 14 cm.

[0251] In yet another aspect, the distal end of the reinforcing jacket abuts or at least partially overlaps the proximal portion of the outer layer. It is further understood that the distal end of the reinforcing jacket is seamlessly bonded to at least a portion of the proximal portion of the outer surface of the outer layer. It is understood that the reinforcing jacket, as described in this aspect, can include all of the components of the reinforcing jacket disclosed above.

[0252] In yet another aspect, a sheath having any one of the configurations disclosed above and including a ballooning guard is also disclosed. The balloon guard, similar to the reinforcing jacket disclosed above, is configured to accommodate different insertion depths of the sheath and prevent excessive outer layer ballooning in the portion of the sheath that remains outside the patient's body without affecting the force that expands the sheath. The ballooning guard is configured to remain outside the patient's body and not be inserted into the patient's anatomy.

[0253] In aspects disclosed herein, a ballooning guard has a proximal end and a distal end and is positioned over at least a portion of the outer layer, the ballooning guard configured to remain outside the subject's blood vessel and maintain substantial hemostasis.

[0254] The ballooning guard as described in the present disclosure may be collapsible. In yet another aspect, the ballooning guard may be configured to adjust its length based on the insertion depth of the sheath.

[0255] In some embodiments, the ballooning guard's inner diameter can be large enough or have minimal resistance to expansion up to a certain diameter so as not to affect the force required to expand the sheath or advance the delivery system through the sheath. Once the ballooning guard reaches a certain diameter, the force required to expand the ballooning guard increases significantly, allowing it to resist blood pressure and stop ballooning. It is understood that the ballooning guard need not prevent ballooning from initiating, but can be included to prevent the outer layer from over-expanding and rupturing, compromising hemostasis. Some exemplary schematic diagrams of balloon guards are shown in FIGS. 29E-29F. The ballooning guard 3125 is disposed on the outer layer 2908. While blood 2915 can enter the area between the outer layer 2908 and the inner layer 2902, the ballooning guard 3125 prevents sheath rupture and helps maintain hemostasis.

[0256] In yet other embodiments, the proximal end of the ballooning guard is connected to the proximal-most portion of the outer layer and / or the hub of the sheath. The distal end of the ballooning guard radially surrounds at least a portion of the outer layer, and the distal end is not bonded to the outer layer. It is understood that the ballooning guard, as described herein, does not seal against the subject's skin and is inserted into the subject's anatomy 2913.

[0257] In yet other aspects, the ballooning guard can include a braided or coiled sleeve including multiple filaments. Any of the multiple filaments disclosed above can be utilized. In some aspects where a braided or coiled sleeve is present, at least a portion of the multiple filaments at the distal end of the ballooning guard are bonded to one another to allow for shortening of the braided or coiled sleeve and sealing against the outer layer and the patient's skin.

[0258] In still other aspects, the braided or coiled sleeve can also comprise a polymer. Any of the elastomeric polymers disclosed above can be used. In certain aspects, the braid or coil can have a polymer embedded therein. It is understood that the material of the braid or coil can be any material known in the art. In certain aspects, the braid or coil material can comprise a metal or metal alloy. In certain aspects, metals or metal alloys known in the art for use in medical devices can be utilized to make the braid or coil. In some aspects, the braid or coil can be made of a shape memory material. In still other aspects, the braid or coil can be any braid or coil disclosed herein.

[0259] In still other embodiments, the braided material can include a polymer. It is understood that any polymer known in the art can be used to form the braid. In such exemplary, non-limiting embodiments, the polymer can include any known polyolefin, any known polyamide, or any known polyester. In still other embodiments, the braided material can include a fabric. In still other embodiments, the braided sleeve can include a fabric. In still other embodiments, the ballooning guard can include e-PTFE tubing, and the ballooning guard can include e-PTFE tubing, corrugated tubing, or any polymeric tubing having a shape configured to be compressed. In certain embodiments, the ballooning guard can include e-PTFE tubing. In such exemplary, non-limiting embodiments, the e-PTFE tubing can be compressed without losing its shape. In still other embodiments, the ballooning guard can include corrugated tubing. The corrugated tubing allows the guard to be compressed and its length adjusted.

[0260] In such exemplary, non-limiting aspects, the ballooning guard may be made of any polymeric material that can have a shape that allows the material to be compressed. For example, the tubing may be formed from any polymer known in the art. The walls of the tubing may be cut into a pattern that allows it to be compressed without losing its original shape.

[0261] Additionally, any of the embodiments of the sheath configurations disclosed herein can include an external hydrophilic coating on the outer surface of the outer layer. Such a hydrophilic coating can facilitate insertion of any of the sheaths disclosed herein into a patient's blood vessel. Examples of suitable hydrophilic coatings include Harmony™ Advanced Lubricity Coatings and other advanced hydrophilic coatings available from SurModics, Inc., Eden Prairie, MN. DSM Medical Coatings (available from Koninklijke DSM NV, Heerlen, the Netherlands) and other hydrophilic coatings (e.g., PTFE, polyethylene, polyvinylidene fluoride) are also suitable for use with the sheaths.

[0262] A soft tip 102, as shown in FIG. 11 , may also be utilized with any of the sheath configurations disclosed herein. In certain embodiments, the soft tip may comprise low-density polyethylene (LDPE) and may be configured to minimize trauma or damage to a patient's blood vessels as the sheath is guided through the vasculature. For example, in some embodiments, the soft tip portion 102 may be slightly tapered to facilitate passage through blood vessels. The soft tip portion 102 may be secured to the distal end 104 of the sheath 100, such as by thermally bonding the soft tip portion 102 to the inner and outer layers of the sheath 100. Such a soft tip portion 102 may be provided with a lower hardness than other portions of the sheath 100. In some embodiments, the soft tip 102 may have a Shore hardness of about 25 A to about 40 A, including exemplary values ​​of about 28 A, about 30 A, about 32 A, about 35 A, and about 38 A. It is further understood that the Shore hardness may have any value between any two of the above values. In still other embodiments, the soft tip 102 can have a Shore hardness of about 25D to about 40D, including exemplary values ​​of about 28D, about 30D, about 32D, about 35D, and about 38D. The tip portion 102 is configured to be radially expandable to allow the prosthetic device to pass through the distal opening of the sheath 100.

[0263] 11 , the sheath 100 can optionally include at least one radiopaque filler or marker, such as a discontinuous or C-shaped band 112, positioned near the distal end 104 of the sheath 100. The marker 112 can be associated with the inner liner and / or the outer layers 108, 110 of the sheath 100. Such radiopaque tip markers can include materials suitable for use as radiopaque fillers, platinum, iridium, platinum / iridium alloys, stainless steel, other biocompatible metals, or combinations thereof. Materials suitable for use as radiopaque fillers or markers include, for example, barium sulfite, bismuth trioxide, titanium dioxide, bismuth subcarbonate, or combinations thereof. The radiopaque filler may be mixed with or embedded in the layer of elastomeric polymer used to form the outer layer and may comprise from about 5% to about 45% by weight of the outer layer, including exemplary values ​​of about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, and about 40% by weight of the outer polymeric tubular layer. In some embodiments, more or less radiopaque material may be used depending on the particular application.

[0264] The sheaths disclosed herein can be configured to locally expand at specific locations corresponding to the location of a medical device along the length of the lumen, and then locally contract as the medical device passes that specific location. Thus, a bulge may be visible, moving longitudinally along the length of the sheath as the medical device is introduced through the sheath, exhibiting continuous, localized expansion and contraction as the medical device moves down the length of the sheath. In some embodiments, each segment of the sheath locally contracts after removal of the radially outward (insertion) force, thereby reducing the lumen's original rest diameter d. r can be made to recover.

[0265] In some embodiments, each segment of the sheath locally contracts after removal of the radially outward force, thereby reducing the lumen's original rest diameter d rThe axial direction of the sine wave can be at least partially returned to the axial direction.

[0266] method Aspects of the present disclosure also relate to a method of making a sheath having a proximal end and a distal end, the method comprising forming a variable diameter inner liner by winding a sheet having a first edge and a second edge, the sheet defined by inner and outer surfaces in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming an overlapping portion, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, and the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis; and forming an outer layer having an inner surface and an outer surface, the outer layer extending around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the inner liner, the outer layer comprising a braid and a layer of an elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface, wherein the variable diameter inner liner is configured to have a predetermined rest diameter d by sliding a first edge of a sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through a lumen of the inner liner. r to expansion diameter d e The system is configured to extend to

[0267] Various methods can be used to manufacture the sheaths discussed above and below throughout this disclosure. For example, FIGS. 7 and 8 illustrate block diagrams of exemplary methods for manufacturing sheaths in various embodiments. Various method steps are also shown in FIGS. 9A-9K. In certain embodiments, as shown in FIG. 9A, the inner liner can be formed from an extruded tube 903 having inner and outer surfaces and any of the thicknesses described above. The extruded tube can be cut 905 along its length to form sheets. In certain embodiments, the inner and / or outer surfaces of the tube can be surface treated, for example, by plasma etching, chemical etching, or other suitable surface treatment methods. In some exemplary embodiments in which the outer surface of the inner liner is treated, the treatment can provide a better bond with the outer layer when formed. In still other embodiments, the inner surface of the inner liner can be ribbed. In such exemplary embodiments, the ribbed surface can facilitate reduced contact points with the prosthetic device, reducing friction. In still other embodiments, the initial extruded tube 903 may be manufactured by coextrusion with multiple layers of the same or different polymers, as described herein. It is understood that one skilled in the art may select the composition of the inner liner depending on the desired application. In certain embodiments, the decision to use a particular material for the inner liner may depend on optimizing the desired stiffness, wall thickness, and lubricity.

[0268] In still other embodiments, one or more mandrels may be provided (steps 700 or 800 in FIGS. 7 and 8, respectively). The mandrels may include an outer coating, such as a Teflon coating, and the diameter of the mandrels may be adjusted to the desired rest diameter d of the resulting sheath. r9B, a sheet formed by cutting 905 extruded tube 903 may be wound in a spiral configuration around mandrel 901 to form inner liner 902 (steps 702 or 802 in FIGS. 7 and 8, respectively), such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming overlapping portion 902c, wherein a first edge (not shown) of the sheet is slidable along at least a portion of the inner surface of the sheet and a second edge 902b is slidable along at least a portion of the outer surface of the sheet.

[0269] In yet other exemplary embodiments, a quantity of first lubricant 910 (FIGS. 9C-9E) may be optionally applied to the outer surface of the inner liner in steps 705 and 805 (FIGS. 7 and 8, respectively). The presence of this lubricant material can reduce friction between the inner liner and the outer layer of the final sheath. In still other embodiments, a quantity of second lubricant 908 may be applied between the overlapping and sliding portions of the inner liner in steps 703 and 803 to further improve sliding and reduce friction. (FIG. 9D shows the inner liner with two optional lubricants, with the mandrel hidden from view.) In still other embodiments, it is understood that the inner liner formed using the mandrel can have any rest diameter as described above. In certain embodiments, the rest diameter d r is substantially uniform along the longitudinal axis of the lumen. r varies along the longitudinal axis of the lumen and has a rest diameter d at the proximal end r is the rest diameter d at the distal end r is greater than.

[0270] In still other embodiments, the method can further include providing a braid or coil (steps 704 and 804). It is understood that any of the braids or coils described above can be used in this step. In still other embodiments, the braid or coil is attached to the inner liner, as shown in step 706 of FIG. 7. In some exemplary embodiments, the braid or coil 904 can be attached to a first lubricant 910, which can be present on the outer surface of the inner liner, as shown in FIG. 9F. It is understood that in some embodiments, the second lubricant can be present on only a portion of the outer surface of the inner liner. In still other embodiments, the disclosed sheath can have segments where the first lubricant is present and the braid or coil is attached to the first lubricant, while other segments where the second lubricant is not present and the braid or coil is attached directly to the outer surface of the inner liner. It is understood that the location of these particular segments can be determined by one of skill in the art depending on the desired application. It is understood that attachment of the braid or coil can be performed by any method known in the art. In some non-limiting embodiments, the braid or coil can be provided as a cylindrical tube and can be slid over an inner liner or first lubricant, if present.

[0271] In yet other embodiments, the method can further include providing a layer of elastomeric polymer, as shown in step 708. It is understood that any of the elastomeric polymers disclosed above can be used. The particular polymer can be selected based on the desired properties of the disclosed sheath, such as the level of stiffness and hemostasis. The layer of elastomeric polymer can be provided in any form known in the art. In certain non-limiting embodiments, the elastomeric polymer can be provided as a cylindrical tube 906 (FIG. 9G). In still other embodiments, the elastomeric polymer can be attached to an inner liner and a braid or coil (step 710). For example, FIG. 9G shows an embodiment in which a cylindrical tube of elastomeric polymer 906 is used to slide over an inner liner with a first lubricant 910 overlying the outer surface of the inner liner and the braid or coil 904.

[0272] In yet other aspects, the disclosed methods can include embedding a braid or coil in a layer of elastomeric polymer (step 711, FIG. 7 ). It is understood that the sheath can include various segments. In some aspects, some of the segments can include a braid or coil embedded in a layer of elastomeric polymer, while in other segments, the braid or coil is separate from the layer of elastomeric polymer. Furthermore, it is understood that in some aspects, the sheath can have a braid or coil embedded in an elastomeric polymer along the entire length of the sheath, while in other aspects, the braid or coil is not embedded in an elastomeric polymer along the entire length of the sheath. Furthermore, it is understood that any method known in the art can be used to embed a braid or coil in an elastomeric polymer. In some aspects, the application of heat can be utilized. In certain aspects, the use of heat shrink tubing can be utilized to embed the braid or coil in the elastomeric polymer. It is understood that the heat shrink tubing is removed after the embedding step is complete. In yet other embodiments, the braid or coil may be embedded within a layer of elastomeric polymer by placing the assembly in an oven or otherwise heating it.

[0273] In still other embodiments, a soft, atraumatic tip may be provided at the distal end of the resulting sheath (step 712). In still other embodiments, an outer layer comprising a braid or coil and a layer of elastomeric polymer is at least partially bonded to the inner liner. It is understood that this bonding may be accomplished by any method known in the art. In certain embodiments, heat shrink is applied to the bonded and heated portions to form a bond between the inner liner and the outer layer, as shown in step 714. In still other embodiments, the bond between the bonded inner liner and outer layer may be achieved by placing the assembly in an oven or otherwise heating. In still other embodiments, the bonding is achieved by heating at a temperature of about 350°F to about 550°F for a time effective to form a bond between at least a portion of the outer layer and at least a portion of the inner liner. In still other embodiments, the heating may be at a temperature of about 375°F, about 400°F, about 425°F, about 450°F, about 475°F, about 500°F, or about 525°F. In still other embodiments, the time effective to form a bond may include from about 1 second to about 60 seconds, including exemplary values ​​of about 5 seconds, about 10 seconds, about 15 seconds, about 20 seconds, about 25 seconds, about 30 seconds, about 35 seconds, about 40 seconds, about 45 seconds, about 50 seconds, and about 55 seconds. However, it is further understood that this time is not limited and may have any value necessary to provide an effective bond, for example, from about 1 second to about 5 hours. It is further understood that if heat shrink tubing was used to obtain the desired bond, the heat shrink tubing is removed (step 716, FIG. 7).

[0274] In yet other embodiments, as shown in FIG. 9I, the bonding step can also include a first strip 920 of elastomeric polymer applied to at least a portion of the outer surface of the sheet, not including the overlapping portion 902c, along at least a portion of the longitudinal axis of the lumen, before or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of inner liner. It is understood that in some exemplary embodiments, this first strip can be applied before attaching the braid or coil, as shown in FIG. 9I. In still other embodiments, the location where the first strip is applied does not include the first lubricant. However, it is understood that in such embodiments, the first lubricant can be present in other locations.

[0275] In yet other exemplary embodiments, the method can include a second strip 922a of elastomeric polymer that can be applied to at least a portion of the outer surface of the sheet at the proximal end of the sheath before or during the step of bonding at least a portion of the inner surface of the layer of elastomeric polymer to at least a portion of the outer surface of the sheet of inner liner. It is understood that in some exemplary embodiments, this second strip can be applied before attaching a braid or coil, as shown in FIG. 9J . In still other embodiments, the location where the second strip is applied does not include the first lubricant. However, it is understood that in such embodiments, the first lubricant can be present in other locations. In still other embodiments, the method can include a third strip 922b of elastomeric polymer that can be applied to at least a portion of the outer surface of the sheet at the distal end of the sheath before or during the step of bonding at least a portion of the inner surface of the layer of elastomeric polymer to at least a portion of the outer surface of the sheet of inner liner. It is understood that in some exemplary embodiments, this second strip can be applied before attaching a braid or coil, as shown in FIG. 9J . In still other embodiments, the location where the third strip is applied does not contain the first lubricant. However, it is understood that in such embodiments, the first lubricant can be present in other locations. In still other embodiments, both the second and third elastomeric polymers are present. In other embodiments, only one of the second and third elastomeric polymers is present. It is further understood that the first, second, and third elastomeric polymers can be the same or different. It is also understood that the first, second, and third elastomeric polymers can be the same as the elastomeric polymer layer present in the outer layer and can include any elastomeric polymer described herein.

[0276] Figure 9K shows an elevational view of the sheath at step 718 of Figure 7. The sheath 900 has been made according to the methods and processes described and can be attached or bonded to the housing 101, such as by bonding the proximal end of the sheath 900 to the polycarbonate housing 101.

[0277] Several alternative embodiments are shown in FIGS. 8 and 9H. In such alternative embodiments, the outer layer is preformed and then attached to the inner liner positioned on a mandrel. In such embodiments, the provided layer of elastomeric polymer is first attached to the braid or coil (step 808) before being attached to the inner liner. In yet other embodiments, the method can also include the step of partially embedding the braid or coil within the layer of elastomeric polymer (step 809) before attaching both the elastomeric polymer and the braid or coil to the inner liner. However, the step of partially embedding the braid or coil within the layer of elastomeric polymer can also be performed after the braid or coil and the layer of elastomeric polymer are attached to the inner liner (step 811). Steps 812-818 can be performed similarly to steps 712-718.

[0278] In yet other embodiments, as shown in FIG. 9I, the bonding step can also include a first strip 920 of elastomeric polymer applied to at least a portion of the outer surface of the sheet, not including the overlapping portion 902c, along at least a portion of the longitudinal axis of the lumen, before or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the inner liner. It is understood that in some exemplary embodiments, this first strip can be applied before attaching the preformed outer layer comprising the braid or coil and the elastomeric polymer, as shown in FIG. 9I. In still other embodiments, the location where the first strip is applied does not include the first lubricant. However, it is understood that in such embodiments, the first lubricant can be present in other locations.

[0279] It is understood that these alternative embodiments can also include a step in which a second strip of elastomeric polymer 922a can be applied to at least a portion of the outer surface of the sheet at the proximal end of the sheath before or during the step of bonding at least a portion of the inner surface of the layer of elastomeric polymer to at least a portion of the outer surface of the sheet of inner liner. It is understood that in some exemplary embodiments, this second strip can be applied before attaching a preformed outer layer comprising a braid or coil and elastomeric polymer, as shown in FIG. 9J . In still other embodiments, the location where the second strip is applied does not include the first lubricant. However, it is understood that in such embodiments, the first lubricant can be present in other locations. In still other embodiments, these methods can also include a third strip of elastomeric polymer 922b can be applied to at least a portion of the outer surface of the sheet at the distal end of the sheath before or during the step of bonding at least a portion of the inner surface of the layer of elastomeric polymer to at least a portion of the outer surface of the sheet of inner liner. It is understood that in some exemplary embodiments, this third strip may be applied prior to attaching the preformed outer layer comprising the braid or coil and the elastomeric polymer, as shown in Figure 9J. In still other embodiments, the location where the third strip is applied does not include the first lubricant. However, it is understood that in such embodiments, the first lubricant may be present in other locations. In still other embodiments, both the second and third elastomeric polymers are present.

[0280] Also disclosed herein are methods for making additional sheath configurations. For example, a method for making a sheath having a proximal end and a distal end is disclosed herein. Such methods include forming a variable diameter inner liner by providing an elongated, single-lumen tubing having at least one polymer layer; longitudinally cutting at least a portion of the circumference of the elongated, single-lumen tubing to form a sheet having a first longitudinal edge and an opposite second longitudinal edge and having an inner surface and an outer surface; and then forming a variable diameter inner liner by winding the sheet in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming an overlapping portion, wherein the first edge of the sheet is slidable along at least a portion of the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, and the inner surface of the sheet defines a lumen of the sheath having a longitudinal axis.

[0281] It is understood that the elongated single-lumen tubing can be extruded or coextruded from any of the polymers or compounds disclosed above. For example, but not limited to, the elongated single-lumen tubing can comprise at least one polymer, including polyolefin, polyamide, fluoropolymer, copolymers thereof, coextrusions thereof, or mixtures thereof. In yet another embodiment, the elongated single-lumen tubing is a composite material comprising a polyolefin and a lubricious filler. In such an exemplary embodiment, the polyolefin can be high-density polyethylene. In yet another embodiment, the lubricious filler can comprise a polytetrafluoroethylene (PTFE) filler. In such an embodiment, the lubricious filler can be present in an amount of about 5 wt% to about 20 wt% of the total weight of the composite.

[0282] For example, but not by way of limitation, the tubular body can be extruded to form an elongated tubing comprising a composite material that can include a polyolefin present in an amount from greater than 0 wt% to less than 100 wt% based on the total weight of the composite material, and a lubricious filler present in an amount from about 5 wt% to about 20 wt% of the total weight of the composite material.

[0283] The extruded or co-extruded elongated single lumen tubing can have a coefficient of friction of less than about 0.5.

[0284] In still other embodiments, the single-lumen tubing can be manufactured by coextrusion with multiple layers of the same or different polymers, as described herein. In still other embodiments, the tubing can be coextruded with any of the tie layers disclosed above, as disclosed above. For example, in such exemplary embodiments in which a tie layer is present, the elongate tubing can comprise any of the polymers disclosed above, and the tie layer can be disposed on the inner surface of the tubing or / and the outer surface of the tubing.

[0285] The elongated tubing is used to form the inner liner, and it is understood that any of the materials disclosed above may be used. In yet other embodiments, a lubricious liner may be placed on the inner surface of the tubing and / or the outer surface of the tubing before cutting the tubing to form the helical configuration of the inner liner. It is understood that the lubricious liner, if present, may be placed on a tie layer. In certain embodiments, a tie layer is used to bond the lubricious liner to the polymer layer to form the elongated tubing. In still other embodiments, at least a portion of the inner surface of the elongated tubing may be ribbed. In such exemplary embodiments, the ribbed surface may facilitate reducing contact points with the prosthetic device, reducing friction.

[0286] In still other embodiments where a tie layer and / or a lubricious liner is present, at least a portion of the lubricious liner may also be ribbed. Also, in such embodiments, tubing comprising any of the above-disclosed polymers, tie layers, and lubricious liner has a coefficient of friction of less than about 0.5.

[0287] The elongated tubing is then placed over a mandrel and cut around at least a portion of the circumference of the tubing as disclosed above. In yet another embodiment, the method of forming the inner liner is similar to the method shown in Figure 9A. The inner liner may be formed from a single lumen extruded tube 903 having an inner surface and an outer surface and any of the thicknesses described above. This extruded tube may be cut 905 along its length to form a sheet.

[0288] Additionally, in certain embodiments, the inner and / or outer surfaces of any of the single-lumen tubings disclosed above may be further surface treated, for example, by plasma etching, chemical etching, or other suitable surface treatment methods. In some exemplary embodiments in which the outer surface of the inner liner is treated, the treatment may provide a better bond with the outer layer when formed. It is understood that one skilled in the art may select the composition of the inner liner depending on the desired application. In certain embodiments, the decision to use a particular material for the inner liner may depend on optimizing the desired stiffness, wall thickness, and lubricity.

[0289] The formed sheet may then be placed on an additional mandrel, which may be provided with an outer coating such as a Teflon coating, and the diameter of the mandrel may be adjusted to the desired rest diameter d of the resulting sheath. r9B, a sheet formed by cutting 905 extruded tube 903 can be wound in a spiral configuration around mandrel 901 such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming overlapping portion 902c, wherein a first edge (not shown) of the sheet is slidable along at least a portion of the inner surface of the sheet and a second edge 902b is slidable along at least a portion of the outer surface of the sheet. It is understood that any of the spiral configurations disclosed above can be obtained.

[0290] For example, the sheet is wound so that the first and second edges of the sheath are substantially aligned in a spaced-apart relationship along a vertical axis passing through the thickness of the sheath. In such embodiments, the spaced-apart relationship can include a portion of the sheet located between the first and second edges along the vertical axis. In certain embodiments, the sheet is wound so that when the sheath is in an unexpanded rest state, the inner liner includes at least two layers of the sheet overlapping each other along at least a portion of the circumference of the sheath. In other embodiments, when the sheath is in an unexpanded rest state, at least a portion of the circumference of the sheath includes three layers of the sheet overlapping each other. Also, when the sheath is wound into a spiral configuration, the first edge of the sheet can be substantially aligned with a vertical axis passing through the thickness of the sheath, and the second edge is circumferentially offset from the vertical axis. In such configurations, in some embodiments, the inner liner includes one layer of the sheet without overlapping portions along at least a portion of the circumference of the sheath.

[0291] However, in certain embodiments, the inner liner can be formed from extruded double-lumen tubing. The extruded double-lumen tubing can include any of the polymers or compounds disclosed above. An exemplary schematic diagram of a method for making an inner liner from such double-lumen tubing is shown in FIGS. 20A-20C. The double lumen 2000 can include a first channel 2002 having an inner surface 2002a and an outer surface 2002b, and a second channel 2004 having an inner surface 2004a and an outer surface 2004b. The second channel 2004 is positioned within the first channel 2002 such that at least a portion of the circumference of the first channel and at least a portion of the circumference of the second channel have at least one shared inner surface and at least one shared outer surface 2006. In such a configuration, the outer surface 2002b of the first channel 2002 defines the outer surface of the double-lumen tubing.

[0292] It is understood that the double lumen tubing may include any of the layers disclosed above.

[0293] For example, the double lumen tubing may be co-extruded from the composite material described above. In such exemplary embodiments, the first channel may comprise the composite material, or the second channel or both may comprise the composite material described above.

[0294] In yet other embodiments, the double-lumen tubing can be coextruded with any of the tie layers disclosed above, and the tie layer can be coextruded with the first channel or the second channel, or both. In still other embodiments, any of the lubricious liners disclosed above can be disposed in the tie layer. It can be disposed, for example, in the first channel or the second channel, or both.

[0295] 20B, the first channel can be cut longitudinally along at least a portion of the perimeter 2008 of the first channel that is not shared with the perimeter of the second channel to form a first sheet 2010. The first sheet 2010 has a first edge 2012 and a second edge 2014, and the second channel is disposed longitudinally along at least a portion of the first sheet 2004, such that at least a portion of the perimeter of the second channel has at least a portion with a surface 2016 shared with the first sheet along the length of the first sheet and along the length of the second channel.

[0296] The second channel is then cut 2018 longitudinally at a portion of the periphery of the second channel that abuts the surface 2016 shared with the first sheet to form a first edge 2022 and a second edge 2024, the second edge being defined by a portion of the surface 2016 shared with the first sheet.

[0297] In yet another embodiment, as shown in FIG. 20C , the first sheet and the second sheet are wound into a spiral configuration, whereby a shared surface 2016 between the second sheet and the first sheet forms a first portion 1802 (2016) of the inner liner having a first surface and an opposite second surface. At least a portion 1806 of the second sheet forms a first segment of the inner liner having a first surface and an opposite second surface. A portion 1810 of the first sheet adjacent to the second end of the second sheet and extending to the first end of the first sheet forms a second segment of the inner liner having a first surface and an opposite second surface. And a portion 1808 of the first sheet adjacent to the second end of the second sheet and extending to the second end of the first sheet forms a third segment of the inner liner having a first surface and an opposite second surface. In such a spiral configuration, as shown in Figures 20C and 18, at least a portion of the first surface of the second segment overlaps with at least a portion of the second surface of the first segment, at least a portion of the first surface of the third segment overlaps with at least a portion of the second surface of the second segment, at least a portion of the first surface of the third segment overlaps with at least a portion of the second surface of the first segment, the first surface of the first portion extends within the first surfaces of the first segment, the second segment, and the third segment, and the second surface of the first portion extends within the second surfaces of the second and third segments.

[0298] In certain aspects, regardless of whether the inner liner is formed from single-lumen or double-lumen tubing, prior to the cutting step, the method can include disposing a quantity of lubricant, It is understood that the lubricant can be disposed on any surface of any channel.

[0299] In still other aspects, the lubricant may be applied manually, in other aspects, the lubricant may be applied by pad printing, in still other aspects, the lubricant may be applied by spraying.

[0300] It is understood that any of the lubricants disclosed above may be used.

[0301] When the lubricant is applied manually, any technique known in the art may be utilized, for example, but not limited to, the lubricant may be applied with a brush, cloth, pad, or the like.

[0302] In some embodiments, the lubricant is deposited by pad printing. During pad printing, a quantity of lubricant is deposited into a recessed channel in the plate. The length and width of the channel can be predetermined as desired. For example, the length and width of the channel can correspond to the desired area on the surface of the inner liner where the lubricant will be deposited. The volume of the channel can also be defined, thereby partially determining the total amount of lubricant transferred. In such embodiments, a soft pad can be dipped into the channel, pick up the lubricant, and moved onto the desired portion of the inner liner. The pad can then be stamped onto a predetermined portion of the liner to transfer the lubricant onto the surface of the inner liner.

[0303] It is understood that in the embodiments disclosed herein, a predetermined amount of lubricant is applied to a predetermined location (predetermined portion) on the surface of the inner liner. In such embodiments, the methods disclosed herein allow for substantial control of both the application area and the amount of lubricant used. As disclosed above, because the depth of the channels can be controlled, the amount of lubricant placed on the surface of the inner liner can also be substantially controlled.

[0304] In embodiments in which a lubricant is transferred onto the surface of the inner liner using pad printing, any of the lubricants disclosed above may be utilized. In certain embodiments, the lubricant used in the pad printing method is substantially viscous. In certain exemplary, non-limiting embodiments, the lubricant may have a viscosity of about 600 cP to about 1,200 cP. In still other embodiments, it is understood that the viscosity of the lubricant may be adjusted by adding more solids or more solvent to the lubricant composition. For example, but not limited to, a lubricant such as MEDI 0-6670 (or similar) may be thickened beyond its standard viscosity.

[0305] It will be appreciated that the use of pad printing allows for the application of lubricant to very specific portions of the inner liner with tight tolerances. In certain embodiments, the lubricant may contain a fluorescent substance or any other material that allows for its specific location on the device to be determined. In such embodiments, for example, the location of a specific lubricant can be determined under UV light. This allows for easy quality control to determine whether the lubricant has been applied to the desired portion of the sheath.

[0306] In yet another aspect, substantially precise pad printing can help reduce pushing forces by reducing friction in the most relevant areas of the sheath, while simultaneously preventing unwanted migration of lubricant.

[0307] In certain embodiments, the lubricant may be applied around a portion of the circumference of the inner liner, while in other embodiments, the lubricant may be applied around the entire outer surface of the inner liner.

[0308] In yet other embodiments, the lubricant can be transferred in a predetermined pattern. For example, it can be transferred in a "striped" pattern. However, it is understood that such patterns are merely exemplary. The pattern can have any regular or irregular shape. For example, if the pattern is a striped pattern, the lubricant can be disposed in multiple stripes along the entire length of the inner liner or along a portion of the inner liner. In still other embodiments, the pattern can have a triangular, tapered, oval, circular, rectangular, or any irregular shape. The pattern can be determined based on the desired application and / or the desired location on the outer surface of the inner liner.

[0309] In yet another embodiment, the inner liner can be rotated by the pad printer between runs, allowing the printer to create lines of lubricant (or any other desired shape) in new locations along the surface of the inner liner. In addition to precisely controlling the amount of lubricant applied to the inner liner and its location, this method can make sheath manufacturing more cost-effective by reducing the amount of lubricant and the number of sheaths that may be discarded due to inaccurate application of lubricant, which can affect overall sheath performance.

[0310] In yet another aspect, the lubricant can be applied by spray coating. In such a method, the lubricant is loaded into a sprayer. The sheath, or more specifically, the inner liner, is mounted on a mandrel that can rotate about the longitudinal axis of the sheath. The lubricant is then sprayed onto the rotating sheath and translated from a desired portion of the length of the inner liner to ensure substantially uniform coverage. The amount of lubricant sprayed onto the inner liner, the speed at which the nozzle moves along the sheath, and the rotational speed of the sheath can all be specified to optimize this application process.

[0311] In certain embodiments, any of the lubricants disclosed above may be used. In embodiments where spray coating is utilized, the viscosity of the lubricant is 600 cP or less. Spray coating uses equipment that atomizes a solution introduced into a spray coater. The resulting spray can be used to coat a variety of devices. In the case of expandable sheath devices, the lubricant is mixed and fully prepared before being introduced into the spray coater.

[0312] To apply the lubricant to the inner liner in a substantially uniform manner, the inner liner is mounted on a mandrel configured to rotate along the longitudinal axis of the sheath at a specified speed. A sprayer nozzle then sprays atomized droplets of the lubricant solution onto the inner liner. The nozzle translates, moving horizontally along the length of the sheath as it rotates. The speed can be adjusted to optimize the amount of lubricant sprayed onto the inner liner. It is understood that if more lubricant is needed, the speed is slowed so the nozzle can remain at a given position along the surface of the inner liner for a longer period of time, and vice versa. Similar to pad printing, the lubricant can be composed of fluorescent components so that it is clearly visible under black light, revealing the areas of the sheath coated with the lubricant.

[0313] In yet another embodiment, after the lubricant is applied to the surface of the inner liner, the lubricant is cured. It is understood that curing can occur under any conditions effective to provide the desired results. In certain exemplary, non-limiting embodiments, curing occurs in an oven. The curing temperature and timing can be dictated by the particular lubricant used in the method described above.

[0314] In yet another aspect, the method further includes disposing an outer layer over at least a portion of the outer layer of the inner liner, and sliding a first longitudinal edge of the sheet along at least a portion of the inner surface and a second longitudinal edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner, thereby achieving a predetermined rest diameter d. r to expansion diameter d eThe method can include forming a sheath configured to expand into the catheter.

[0315] In certain embodiments, the outer layer can be fabricated by extruding a tubular body to form an elongated tube comprising a first polymer layer, the first polymer layer comprising a first composite composition comprising from greater than 0 wt % to less than 100 wt % of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65 wt % of an inorganic filler, based on the total weight of the first composite composition; and up to about 20 wt % of a solid lubricant filler, based on the total weight of the first composite composition. This elongated tube can then be placed into any of the above-disclosed inner liners to form the outer layer of the sheath. It is understood that any of the above-disclosed additional layers can also be present between the inner liner and the outer layer.

[0316] In yet another aspect, an outer layer as provided herein can be made by coextruding an elongated bump tubing comprising a first polymer layer and a second polymer layer, and then disposing such tubing on the surface of any one of the inner liners disclosed herein, wherein the first polymer layer comprises a first composite composition, the first composite composition comprising, based on the total weight of the first composite composition, from greater than 0 wt% to less than 100 wt% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof, less than about 65% of an inorganic filler, based on the total weight of the first composite composition, and up to about 20% of a solid lubricant filler, based on the total weight of the first composite composition, the second polymer layer comprising polyurethane, the first polymer layer defining the inner surface of the tubing, and the second polymer layer defining the outer surface of the tubing. It is understood that any of the above-disclosed additional layers can also be present between the inner liner and the outer layer.

[0317] In yet another aspect, the method also includes: a) forming an inner liner by any of the above-disclosed methods; and then b) disposing a first polymer layer comprising a first composite composition, the first composite composition comprising, based on the total weight of the first composite composition, greater than 0% to less than 100% polymer comprising a polyether block amide, a polyurethane, or a combination thereof; less than about 65% inorganic filler, based on the total weight of the first composite composition; and up to about 20% solid lubricant filler, based on the total weight of the first composite composition, the first polymer layer being disposed on a proximal portion of the inner liner and having a length of about 5 cm to about 15 cm; and c) disposing a second polymer layer comprising polyurethane on the first polymer layer, the second polymer layer extending along the length of the sheath, the first polymer layer and the second polymer layer together forming the outer layer of the sheath.

[0318] It is understood that any method known in the art can be utilized to form any of the compositions disclosed herein. In certain embodiments, the components present in any of the elongated tubes disclosed herein are provided to form a composite. The compounds are then mixed to form a substantially homogeneous mixture. In yet other embodiments, the mixture is homogeneous. In still other embodiments, the mixture is extruded to form an elongated tube having a first polymer layer. The formed first polymer layer can include any (and any combination of) the compositions and properties disclosed above.

[0319] In yet other embodiments, the method also includes forming an elongated tube comprising two or more layers, as disclosed above. In such embodiments, for example, when the elongated tube comprises any of the first and second polymer layers disclosed above, such layers can be coextruded to form the elongated tube as disclosed. Any extrusion device known in the art can be used to obtain any desired elongated tube.

[0320] Also disclosed herein are methods for bonding the outer layer and inner liner, if desired. It is understood that any method known in the art may be used to form the bond. In certain embodiments, heat treatment may be utilized. For example, the sheath may be inserted into heat-shrink tubing and heated together to a temperature that allows for at least a partial bond between the inner liner and outer layer.

[0321] Some additional exemplary embodiments can include laser welding, compression head welding, or ultrasonic welding, as shown in Figures 28A-28C.

[0322] In yet other embodiments, laser welding may be utilized. In such embodiments, an inner liner may be formed by any of the methods disclosed above. An outer layer comprising any of the compositions disclosed above and formed by any of the methods disclosed above is then placed on the inner liner to form a sheath. It is understood that any of the layers disclosed above may also be provided between the inner liner and the outer surface. The sheath is then positioned on a mandrel configured to rotate. Laser welding uses a focused laser to heat the components at selected locations. The mandrel is aligned with a laser beam configured to move along the longitudinal axis of the sheath a predetermined distance under conditions effective to form a bond (FIG. 28A). In such embodiments, the head of a laser bonder is positioned directly above the center of the sheath, and the sheath may be rotated to align the laser with any desired point on the diameter of the sheath. The laser bonder then moves horizontally across the sheath.

[0323] The bond may be formed at a predetermined portion of the sheath between at least a portion of the outermost surface of the inner liner and at least a portion of the innermost surface of the outer layer, however, it is understood that while other additional layers, such as lubricant or tie layers, may be present, the predetermined location where the bond is formed will be substantially free of lubricant and / or tie layers.

[0324] It is understood that settings on the laser welder can be changed to optimize both the heating level of the device and the bond area. The laser power in watts varies the heat imparted onto the sheath, while the feed rate adjusts the length of time the laser is focused on a given portion of the sheath. The focus position, weld start angle, and weld distance can be used to control the area of ​​the laser, fine-tuned to create the right size bond.

[0325] Additional methods of forming bonds are also disclosed herein, such as the use of a compression head bonder (FIG. 28B). In such methods, inner and outer layers are formed by any of the methods disclosed above and combined to form a sheath. The sheath is then positioned on a mandrel and placed in a radial compression head bonder. Any compression head bonder known in the art may be used. In certain embodiments, the compression head bonder may include a collapsible opening configured to compress the sheath to a predetermined diameter. The radial compression head bonder may include multiple dies, at least one of which may be heated to form a bond at a predetermined portion of the sheath.

[0326] An exemplary, non-limiting bonder, such as that shown in FIG. 28B, can include a total of nine separate dies, eight made from PEEK plastic, and one metal die. The metal die can be heated before use. The machine collapses the jaws of the opening into a smaller diameter and then compresses around the device inserted through the block. The heated die then melts the portion of the inserted component that contacts the die. For use with expandable sheaths, a mandrel is inserted into the lumen of the device to prevent compression of the sheath shaft under the load of the bonder. In certain embodiments, fluorinated ethylene propylene can be placed over the desired bonding area of ​​the sheath to ensure uniform heat transfer and prevent the metal from burning directly through the outer layer. The sheath can be supported laterally in the machine using separate channels. In certain embodiments, the width of the bonding die can be shorter than the length of the sheath; therefore, to lengthen the bonding area, the sheath can be moved horizontally after each run, allowing bonding to be repeated at the desired length along the sheath.

[0327] It is understood that the specific bond and its location can be controlled as desired. For example, the temperature of the metal die can be determined to ensure that it is set at a temperature effective to at least partially melt both the outer layer and inner liner components. In yet another aspect, the compressive force applied to the parts can be adjusted to obtain at least partial melting without substantial damage to the remaining components of the sheath. The final diameter that the opening reaches during bonding can also be predetermined. It is understood that the larger the diameter, the more exposed the metal die is to the parts and the larger the bond area. Furthermore, the length of time that the die is compressed against the sheath can also affect the degree of melting of the components and the strength of the bond.

[0328] In yet other aspects, the method can include ultrasonic welding. In such aspects, the sheath components to be joined are placed in a welding machine and a load is applied from a movable horn. The horn moves at very high speeds and emits a large amount of vibrational energy. This energy is absorbed by the material, which can melt in place. The molten material flows together and achieves a bond when cooled. In some aspects, ultrasonic welding can be used prior to forming the fully assembled sheath. In such aspects, for example, ultrasonic welding can be used to join any desired parts at any stage of manufacture.

[0329] Also disclosed is a method of making a sheath with a reinforcing jacket. In such a method, sheath components, such as an inner liner and an outer layer, are formed by any of the above-disclosed methods and assembled together to form a sheath. Here, a reinforcing jacket having a proximal end and a distal end is positioned to overlap at least a portion of the outer layer. The method further includes substantially seamlessly bonding the distal end of the reinforcing jacket to at least a portion of the outer layer. It is understood that any bonding method disclosed above or generally known in the art may be used.

[0330] The reinforcing jacket may include any of the components disclosed above, the reinforcing jacket including any of the elastomers disclosed above and any of the reinforcing elements disclosed above.

[0331] In yet other embodiments, the reinforcing jacket may be formed by any method known in the art. For example, the reinforcing jacket may be formed by injection molding, extrusion, or a reflow process. In yet other embodiments, any of the reinforcing members disclosed herein may be embedded in a soft polymer to form the reinforcing jacket. For example, without limitation, during a reflow process, the reinforcing element may be placed on a polymer layer and exposed to heat to allow the reinforcing element and polymer to fuse together. In yet other exemplary embodiments, the reinforcing jacket may be formed by injection molding. In such embodiments, the reinforcing element may be positioned in a mold and the polymer injected thereover. In yet other exemplary, non-limiting embodiments, the reinforcing jacket may be formed by an extrusion process. In such exemplary embodiments, a heated polymer may be extruded into a tube to allow the polymer and reinforcing element to combine during parallel feeding of the reinforcing element.

[0332] There is also a method of making a sheath with a ballooning guard. In such a method, sheath components, such as an inner liner and an outer layer, are formed by any of the above-disclosed methods and assembled together to form a sheath. Here, a ballooning guard having a proximal end and a distal end is positioned to overlap at least a portion of the outer layer, the ballooning guard configured to remain outside the subject's blood vessel and maintain hemostasis. The method further includes connecting the proximal end of the ballooning guard to a proximal-most portion of the outer layer and / or a hub of the sheath, the distal end of the ballooning guard radially surrounding at least a portion of the outer layer, the distal end not being attached to the outer layer. The ballooning guard is configured to adjust its length as a function of insertion depth of the inner liner and outer layer of the sheath relative to the subject's blood vessel, as described herein.

[0333] In yet another aspect, the methods disclosed herein can include disposing a hydrophilic coating layer on the outer surface of the layer of elastomeric polymer. Any of the hydrophilic coatings disclosed herein can be used.

[0334] The sheaths of the present disclosure can be used with various methods of introducing a prosthetic device into a patient's vasculature. One such method includes positioning an expandable sheath within a patient's blood vessel, passing the device through an introducer sheath, whereby a portion of the sheath surrounding the device expands to accommodate the device's contours, and automatically returning the expanded portion of the sheath to its original size after the device has passed through the expanded portion. In some methods, the expandable sheath is sutured to the patient's skin at the insertion site so that, once the sheath has been inserted an appropriate distance into the patient's vasculature, the sheath can be prevented from moving once the implantable device begins to move through the sheath.

[0335] The disclosed embodiments of the expandable sheath can be used with other delivery and minimally invasive surgical components, such as introducers and loaders. The introducer can be inserted into the expandable sheath, and the introducer / sheath combination can be fully inserted into the vasculature over a guide device, such as a 0.35" guidewire. Once the sheath and introducer are fully inserted into the patient's vasculature, in some embodiments, the expandable sheath can be sutured in place at the insertion site. In this way, the expandable sheath can be substantially prevented from migrating once positioned within the patient.

[0336] The introducer can then be removed, and a medical device, such as a transcatheter heart valve, can be inserted into the sheath, optionally using a loader. Such methods can further include placing the tissue heart valve in a crimped state on a distal end portion of an elongate delivery device, and inserting the elongate delivery device with the crimped valve through an expandable sheath. The delivery device can then be advanced through the patient's vasculature to the treatment site, where the valve can be implanted.

[0337] Typically, the medical device has an outer diameter larger than the diameter of the sheath in its original configuration. The medical device can be advanced to the implantation site through the expandable sheath, and the expandable sheath can locally expand to accommodate the medical device as the device passes. The radial force applied by the medical device can be sufficient to locally expand the sheath to an expanded diameter (e.g., expanded configuration) only in the area where the medical device is currently located. Once the medical device passes a specific location in the sheath, the sheath can at least partially contract to the smaller diameter of its original configuration. Thus, the expandable sheath can be expanded without the use of an inflatable balloon or other dilator. Once the medical device is implanted, the sheath and the sutures holding it in place can be removed. In some exemplary embodiments, the sheath is removed without rotating it.

[0338] (Example) The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices, and / or methods claimed herein are made and evaluated, and are intended to be purely illustrative and not intended to limit the disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperatures, etc.), but some errors and deviations should be accounted for.

[0339] Unless indicated otherwise, parts are parts by weight, temperature is in degrees Celsius or at ambient temperature, and pressure is at or near atmospheric or full vacuum.

[0340] FIG. 16 shows experimental data measured for the insertion force required to insert a medical device into the disclosed sheath 3 compared to commercially available sheaths 1 and 2. The forces were measured using a typical delivery system on a ZwickRoell push-through tester. It can be seen that the required insertion force measured at the tapered portion of this sheath is less than the insertion force required for the commercially available sheaths 1 and 2. Similarly, the insertion force measured at the constricted body peak shows better results for the disclosed sheath 3 compared to the commercially available sheaths 1 and 2.

[0341] 17 shows experimental data of measured load as a function of expansion for Sheath 3 disclosed herein and commercially available Sheaths 1 and 2. It can be seen that the disclosed sheaths show comparable results to the clinically acceptable commercially available sheaths.

[0342] Exemplary Embodiments Example 1 a sheath for delivering a medical device, the sheath having proximal and distal ends, the variable diameter inner liner comprising a sheet, the sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a cylindrical lumen having a longitudinal axis; and an outer layer having an inner surface and an outer surface, the outer layer extending around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is disposed adjacent to the outer surface of the inner liner, the outer layer comprising a braid or coil and a layer of an elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface, wherein the variable diameter inner liner is configured to have a predetermined rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to expansion diameter d e The sheath is configured to expand.

[0343] Example 2 Rest diameter d r The sheath of any embodiment herein, particularly embodiment Error! Reference source not found., wherein the thickness of the sheath is substantially uniform along the longitudinal axis of the lumen.

[0344] Example 3 Rest diameter d r is variable along the longitudinal axis of the lumen, and the rest diameter d at the proximal end r is the rest diameter d at the distal end r The larger sheath of any of the examples herein, particularly Example Error! Reference source not found.

[0345] Example 4 Expanded diameter d e The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein the sheath is configured to accommodate a medical device passing through the lumen.

[0346] Example 5 The sheath has a predetermined rest diameter d after passage of the medical device through the lumen. r The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., which shrinks to

[0347] Example 6 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the sheet comprises high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or mixtures thereof.

[0348] Example 7 The sheath of any of the examples herein, particularly example Error! Reference source not found., wherein the sheet has a multi-layer structure.

[0349] Example 8 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the inner surface of the sheet is at least partially ribbed.

[0350] Example 9 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. to Error! Reference source not found., wherein the sheet is lubricious and has a coefficient of friction of less than about 0.5.

[0351] Example 10 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein an amount of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer layer.

[0352] Example 11 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein an amount of a second lubricant is disposed between at least a portion of the overlapping portion of the sheet and at least a portion of the sliding portion of the sheet.

[0353] Example 12 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein the outer surface of the layer of elastomeric polymer defines at least a portion of the outer surface of the outer layer.

[0354] Example 13 The sheath of any of the embodiments herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein at least a portion of the inner surface of the layer of elastomeric polymer is partially bonded to at least a portion of the outer surface of the inner liner sheet.

[0355] Example 14 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein at least a portion of the inner surface of the layer of elastomeric polymer defines at least a portion of the inner surface of the outer layer.

[0356] Example 15 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein at least a portion of the braid or coil defines at least a portion of the inner surface of the outer layer.

[0357] Example 16 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., further comprising a first strip of elastomeric polymer disposed along at least a portion of the longitudinal axis of the lumen between at least a portion of the outer surface of the sheet, not including the overlapping portion of the sheet, and the inner surface of the outer layer.

[0358] Example 17 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. to Error! Reference source not found., further comprising a second strip of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the proximal end of the sheath and the inner surface of the outer layer.

[0359] Example 18 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. to Error! Reference source not found., further comprising a third strip of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the distal end of the sheath and the inner surface of the outer layer.

[0360] Example 19 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the braid or coil is an expandable braid or an expandable coil.

[0361] Example 20 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the braid or coil comprises at least one filament comprising stainless steel, nitinol, a polymeric material, or a synthetic material.

[0362] Example 21 The sheath of any example herein, particularly example Error! Reference source not found., wherein the filaments are round filaments or flat filaments.

[0363] Example 22 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. or Error! Reference source not found., wherein the polymeric material is polyester or nylon.

[0364] Example 23 The sheath of any example herein, particularly Example 21, wherein the rounded filaments have a diameter of less than about 0.015 inches.

[0365] Example 24 The sheath of any example herein, particularly Examples 21-22, wherein the flat filaments have a height of less than about 0.006 inches and a width of greater than about 0.003 inches to about 0.015 inches.

[0366] Example 25 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the braid has a crosses per inch (PIC) count of less than 50.

[0367] Example 26 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found., wherein the PIC is variable along the longitudinal axis of the lumen.

[0368] Example 27 The filament is Nitinol, and Nitinol is d e The sheath of any of the examples herein, particularly examples Error! Reference source not found. to Error! Reference source not found., which is heat set at 100°C.

[0369] Example 28 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the filament comprises stainless steel or nitinol, and the filament is configured to be atraumatic at least at the distal end of the sheath.

[0370] Example 29 The sheath of any example herein, particularly example Error! Reference source not found. ~ Error! Reference source not found., wherein the elastomeric polymer comprises a styrenic elastomer, a polyurethane, a latex, a copolymer thereof, a blend thereof, or a coextrusion thereof.

[0371] Example 30 The sheath of any example herein, particularly example Error! Reference source not found., wherein the elastomeric polymer has a Shore A durometer of less than 90.

[0372] Example 31 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein the braid or coil is at least partially embedded within at least a portion of the layer of elastomeric polymer.

[0373] Example 32 The sheath of any of the embodiments herein, particularly embodiments Error! Reference source not found. to Error! Reference source not found., wherein a hydrophilic coating layer is disposed on the outer surface of the outer layer.

[0374] Example 33 A method of making a sheath having proximal and distal ends, comprising the steps of forming a variable diameter inner liner by winding a sheet having a first edge and a second edge, the sheet being defined by inner and outer surfaces in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, thereby forming an overlapping portion, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of a cylinder having a longitudinal axis; forming a side layer, the outer layer having an inner surface and an outer surface and extending around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is disposed adjacent to the outer surface of the inner liner, the outer layer including a braid or coil and a layer of elastomeric polymer having a predetermined thickness and having an inner surface and an outer surface, wherein the variable diameter inner liner is configured to have a predetermined rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to expansion diameter d e The method is configured to extend

[0375] Example 34 The step of forming a variable diameter inner liner includes winding the sheet on a mandrel having a predetermined diameter to form a spiral configuration, the predetermined diameter of the mandrel being equal to the predetermined diameter d of the inner liner. r The method of any example herein, particularly example Error! Reference source not found., being substantially identical to the method of any example herein, particularly example Error! Reference source not found.

[0376] Example 35 Rest diameter d rThe method of any embodiment herein, particularly embodiment Error! Reference source not found. to Error! Reference source not found., wherein the thickness of the lumen is substantially uniform along the longitudinal axis of the lumen.

[0377] Example 36 Rest diameter d r is variable along the longitudinal axis of the lumen, and the rest diameter d at the proximal end r is the rest diameter d at the distal end r Any method of any of the embodiments herein, particularly any of the embodiments Error! Reference source not found. to Error! Reference source not found.

[0378] Example 37 The method of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the step of forming the outer layer includes mounting a braid or coil on the inner liner.

[0379] Example 38 The method of any example herein, particularly example Error! Reference source not found., wherein the step of forming the outer layer further comprises applying an elastomeric polymer onto the blade.

[0380] Example 39 The method of any example herein, particularly example Error! Reference source not found. to Error! Reference source not found., further comprising at least partially embedding a braid or coil within at least a portion of the layer of elastomeric polymer.

[0381] Example 40 The method of any example herein, particularly example Error! Reference source not found. ~ Error! Reference source not found., wherein the step of forming the outer layer includes applying a layer of elastomeric polymer onto a braid or coil, and then applying the layer of elastomeric polymer and the braid or coil onto an inner liner disposed on a mandrel.

[0382] Example 41 The method of any of the embodiments herein, particularly embodiment Error! Reference source not found., further comprising the step of at least partially embedding the braid or coil within at least a portion of the layer of elastomeric polymer before mounting on the inner liner.

[0383] Example 42 The method of any of the embodiments herein, particularly embodiment Error! Reference source not found., further comprising the step of at least partially embedding the braid or coil within at least a portion of the layer of elastomeric polymer after mounting on the inner liner.

[0384] Example 43 The method of any embodiment herein, particularly embodiment Error! Reference source not found. to Error! Reference source not found., wherein the outer surface of the layer of elastomeric polymer defines at least a portion of the outer surface of the outer layer.

[0385] Example 44 The method of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein at least a portion of the inner surface of the layer of elastomeric polymer defines at least a portion of the inner surface of the outer layer.

[0386] Example 45 The method of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein at least a portion of the braid or coil defines at least a portion of the inner surface of the outer layer.

[0387] Example 46 The method of any example herein, particularly example Error! Reference source not found. to Error! Reference source not found., further comprising bonding at least a portion of the inner surface of the layer of elastomeric polymer to at least a portion of the outer surface of the inner liner sheet.

[0388] Example 47 The method of any embodiment herein, particularly embodiment Error! Reference source not found., wherein the bonding step is carried out by heating at a temperature of from about 350°F to about 550°F for a period of time effective to form a bond between at least a portion of the outer layer and at least a portion of the inner liner.

[0389] Example 48 Any of the embodiments herein, particularly the method of embodiment Error! Reference source not found. or Error! Reference source not found., wherein a first strip of elastomeric polymer is applied to at least a portion of the outer surface of the sheet, not including the overlapping portion, along at least a portion of the longitudinal axis of the lumen before or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the inner liner sheet.

[0390] Example 49 Any of the methods herein, particularly examples, particularly examples, Error! Reference source not found. to Error! Reference source not found., wherein a second strip of elastomeric polymer is applied to at least a portion of the outer surface of the sheet at the proximal end of the sheath before or during the step of bonding at least a portion of the inner surface of the layer of elastomeric polymer to at least a portion of the outer surface of the sheet of inner liner.

[0391] Example 50 Any of the methods herein, particularly examples, particularly examples, wherein a third strip of elastomeric polymer is applied to at least a portion of the outer surface of the sheet at the distal end of the sheath before or during the step of bonding at least a portion of the inner surface of the layer of elastomeric polymer to at least a portion of the outer surface of the sheet of inner liner.

[0392] Example 51 The method of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein an amount of a first lubricant is applied to at least a portion of the inner liner such that the first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer liner within the sheath prior to the step of forming the outer layer.

[0393] Example 52 Any of the embodiments herein, particularly the method of embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein an amount of a second lubricant is applied to at least a portion of the overlapping and sliding portions of the sheets prior to the step of forming the outer layer.

[0394] Example 53 The method of any example herein, particularly example Error! Reference source not found.~Error! Reference source not found., wherein the sheet comprises high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or mixtures thereof.

[0395] Example 54 The method of any example herein, particularly example Error! Reference source not found., wherein the sheet has a multi-layer structure.

[0396] Example 55 The method of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the inner surface of the sheet is at least partially ribbed.

[0397] Example 56 The method of any example herein, particularly example Error! Reference source not found. to Error! Reference source not found., wherein the sheet is lubricious and has a coefficient of friction of less than about 0.5.

[0398] Example 57 The method of any embodiment herein, particularly embodiment Error! Reference source not found. to Error! Reference source not found., wherein the blade or coil is an expandable blade or an expandable coil.

[0399] Example 58 The method of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the braid or coil comprises at least one filament comprising stainless steel, nitinol, a polymeric material, or a synthetic material.

[0400] Example 59 The method of any example herein, particularly example Error! Reference source not found., wherein the filament is a round filament or a flat filament.

[0401] Example 60 The method of any example herein, particularly example Error! Reference source not found. or Error! Reference source not found., wherein the polymeric material is polyester or nylon.

[0402] Example 61 The method of any example herein, particularly example Error! Reference source not found. ~ Error! Reference source not found., wherein the rounded filament has a diameter of less than about 0.015 inches.

[0403] Example 62 The method of any example herein, particularly example Error! Reference source not found. to Error! Reference source not found., wherein the flat filament has a height of less than about 0.006 inches and a width of greater than about 0.003 inches to about 0.015 inches.

[0404] Example 63 The method of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the blade has a crosses per inch (PIC) count of less than 50.

[0405] Example 64 The method of any embodiment herein, particularly embodiment Error! Reference source not found., wherein the PIC is variable along the longitudinal axis of the lumen.

[0406] Example 65 The filament is Nitinol, and Nitinol is d e The method of any of the examples herein, particularly examples Error! Reference source not found. to Error! Reference source not found., wherein the material is heat set in the presence of a solvent.

[0407] Example 66 The method of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the filament comprises stainless steel or nitinol, and the filament is configured to be atraumatic at least at the distal end of the sheath.

[0408] Example 67 The method of any example herein, particularly example Error! Reference source not found. ~ Error! Reference source not found., wherein the elastomeric polymer comprises a styrenic elastomer, a polyurethane, a latex, a copolymer thereof, a blend thereof, or a coextrusion thereof.

[0409] Example 68 The method of any example herein, particularly example Error! Reference source not found., wherein the elastomeric polymer has a Shore A durometer of less than 90.

[0410] Example 69 The method of any example herein, particularly example Error! Reference source not found. to Error! Reference source not found., further comprising disposing a hydrophilic coating layer on the outer surface of the layer of elastomeric polymer.

[0411] Example 70 1. A sheath for delivering a medical device, the sheath having proximal and distal ends, the variable diameter inner liner comprising a sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet being wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a cylindrical lumen having a longitudinal axis; and an outer layer having an inner surface and an outer surface, the outer layer extending around at least a portion of the variable diameter inner liner such that the inner surface of the outer layer is disposed adjacent to the outer surface of the inner liner, the outer layer having a predetermined thickness and comprising at least one layer of a first elastomeric polymer having an inner surface and an outer surface, wherein the variable diameter inner liner is configured to have a predetermined rest diameter d by sliding a first edge of the sheet along at least a portion of the inner surface and sliding a second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the inner liner. r to expansion diameter d e The sheath is configured to expand.

[0412] Example 71 Rest diameter d r The sheath of any embodiment herein, particularly embodiment Error! Reference source not found., wherein the thickness of the sheath is substantially uniform along the longitudinal axis of the lumen.

[0413] Example 72 Rest diameter d r is variable along the longitudinal axis of the lumen, and the rest diameter d at the proximal end r is the rest diameter d at the distal end r The larger sheath of any of the examples herein, particularly Example Error! Reference source not found.

[0414] Example 73 Expanded diameter d e The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein the sheath is configured to accommodate a medical device passing through the lumen.

[0415] Example 74 The sheath has a predetermined rest diameter d after passage of the medical device through the lumen. r The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., which shrinks to

[0416] Example 75 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the sheet comprises high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or mixtures thereof.

[0417] Example 76 The sheath of any of the examples herein, particularly example Error! Reference source not found., wherein the sheet has a multi-layer structure.

[0418] Example 77 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the inner surface of the sheet is at least partially ribbed.

[0419] Example 78 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. to Error! Reference source not found., wherein the sheet is lubricious and has a coefficient of friction of less than about 0.5.

[0420] Example 79 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein an amount of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer layer.

[0421] (Example 80) The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein an amount of a second lubricant is disposed between at least a portion of the overlapping portion of the sheet and at least a portion of the sliding portion of the sheet.

[0422] Example 81 The first and second lubricants may be the same or different in any of the examples herein, particularly in example Error! Reference source not found.

[0423] Example 82 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found. ~ Error! Reference source not found., wherein the outer surface of the at least one layer of first elastomeric polymer defines at least a portion of the outer surface of the outer layer.

[0424] Example 83 The sheath of any of the embodiments herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein at least a portion of the inner surface of the at least one layer of first elastomeric polymer is at least partially bonded to at least a portion of the outer surface of the inner liner sheet.

[0425] Example 84 The sheath of any of the embodiments herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., wherein at least a portion of the inner surface of the at least one layer of the first elastomeric polymer defines at least a portion of the inner surface of the outer layer.

[0426] Example 85 The sheath of any embodiment herein, particularly embodiment Error! Reference source not found.~Error! Reference source not found., further comprising a braid or coil arranged to cover at least a portion of the inn...

Claims

1. 1. A sheath for delivering a medical device having a proximal end and a distal end, comprising: a variable diameter inner liner comprising a sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet being wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis, the sheet comprising a polymer layer; an outer layer having a predetermined thickness and having an inner surface and an outer surface; At least one bonding layer and Equipped with The variable diameter inner liner has a first rest diameter d by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the variable diameter inner liner. r to the second expansion diameter d e configured to extend to the tie layer is disposed on the inner surface of the sheet such that when the sheet is in a spiral configuration, the tie layer is disposed between overlapping portions and on at least the inner surface of the lumen; or A pre-tie layer is disposed on the outer surface of the sheet such that when the sheet is in a spiral configuration, the tie layer is disposed between overlapping portions and on the outermost surface of the variable diameter inner liner, sheath.

2. 10. The sheath of claim 1, wherein when the sheath is in an unexpanded rest state, the first edge and the second edge of the sheath are aligned in a spaced-apart relationship along a vertical axis passing through a thickness of the sheath.

3. 10. The sheath of claim 1, wherein the variable diameter inner liner comprises at least two layers of the sheet that overlap each other around at least a portion of the circumference of the sheath when the sheet is in an unexpanded rest state.

4. 2. The sheath of claim 1, wherein when the sheath is in a rest state, the first edge of the sheet is aligned with a vertical axis passing through a thickness of the sheath, and the second edge is circumferentially offset from the vertical axis.

5. The sheath of claim 4 , wherein around at least a portion of the circumference of the sheath, the variable diameter inner liner comprises one layer of the sheet with no overlapping portions.

6. The sheath of claim 1 , wherein an amount of lubricant is disposed between at least a portion of the overlapping portion of the sheet and at least a portion of the sliding portion of the sheet.

7. 10. The sheath of claim 1, wherein the polymer layer of the sheet comprises a composite material including a polyolefin and a lubricious filler.

8. 2. The sheath of claim 1, wherein the tie layer is disposed on the outer surface of the sheet such that when the sheet is in the spiral configuration, the tie layer is disposed on the outermost surface of the variable diameter inner liner between overlapping portions.

9. A sheath for delivering a medical device, having a proximal end and a distal end, comprising: a variable diameter inner liner comprising a sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet being wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis, the sheet comprising a polymer layer; an outer layer having a predetermined thickness and having an inner surface and an outer surface; At least one bonding layer and Equipped with the variable diameter inner liner is configured to expand from a first rest diameter dr to a second expanded diameter de by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the variable diameter inner liner; The tie layer is coextruded with the sheet, sheath.

10. A sheath for delivering a medical device, having a proximal end and a distal end, comprising: a variable diameter inner liner comprising a sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet being wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis, the sheet comprising a polymer layer; an outer layer having a predetermined thickness and having an inner surface and an outer surface; At least one bonding layer and Equipped with the variable diameter inner liner is configured to expand from a first rest diameter dr to a second expanded diameter de by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the variable diameter inner liner; The sheath further comprises at least one lubricious liner disposed on the bonding layer.

11. The sheath of claim 1 , wherein the outer layer comprises polyurethane.

12. A sheath for delivering a medical device, having a proximal end and a distal end, comprising: a variable diameter inner liner comprising a sheet having a first edge and a second edge and defined by an inner surface and an outer surface, the sheet being wound in a spiral configuration such that at least a portion of the inner surface of the sheet overlaps at least a portion of the outer surface of the sheet, the first edge of the sheet being slidable along at least a portion of the inner surface of the sheet and the second edge being slidable along at least a portion of the outer surface of the sheet, the inner surface of the sheet defining a lumen of the sheath having a longitudinal axis, the sheet comprising a polymer layer; an outer layer having a predetermined thickness and having an inner surface and an outer surface; Equipped with the variable diameter inner liner is configured to expand from a first rest diameter dr to a second expanded diameter de by sliding the first edge of the sheet along at least a portion of the inner surface and sliding the second edge of the sheet along at least a portion of the outer surface during application of a radially outward force by passage of a medical device through the lumen of the variable diameter inner liner; The outer layer further comprises a first polymer layer comprising a first composite composition, the first composite composition comprising: a polymer comprising a polyether block amide, a polyurethane, or a combination thereof, the polymer being from greater than 0 wt % to less than 100 wt %, based on the total weight of the first composite composition; less than 65% inorganic filler, based on the total weight of the first composite composition; up to 20% solid lubricant filler, based on the total weight of the first composite composition; Including the sheath.

13. The sheath of claim 12 , wherein the first composite composition further comprises at least one adhesion-reducing compound.

14. 13. The sheath of claim 12, wherein the outer layer comprises a second polymer layer comprising a second composite composition comprising from greater than 0 wt% to 100 wt% of a second polymer comprising a polyether block amide, a polyurethane, or a composition thereof.

15. The sheath of claim 1 , further comprising a hydrophilic coating disposed on an outermost surface of the sheath.

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