Expandable Sheath

Abstract

To provide a favorable medical device.SOLUTION: Described embodiments include a medical device having a frame including a plurality of strut elements arranged to form a tubular framework, and a covering extending along a portion of the frame such that the frame and the covering define a sheath having a lumen extending therethrough.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Provisional Application No. 62 / 837,060, filed April 22, 2019, and also claims the benefit of Provisional Application No. 62 / 876,466, filed July 19, 2019, both of which are incorporated by reference in their entireties for all purposes.

[0002] Field SUMMARY The present disclosure relates to introducer sheaths for medical procedures involving the delivery of endoprostheses and other medical devices to treatment areas of a patient's vasculature. [Background technology]

[0003] background Current methods for providing medical treatments to the human vasculature include the use of catheters and endovascularly deliverable medical devices, non-limiting examples of which include endoprostheses such as stents and stent-grafts (self-expanding or otherwise), bifurcated stents and stent-grafts, drug-eluting stents and vascular filters, as well as the endovascular delivery of intraluminal imaging devices.

[0004] Such catheters and other medical devices sometimes enter the body through an orifice or incision. In some instances, a medical conduit is inserted through the orifice or incision and the catheter and other medical device is threaded through the medical conduit. Such medical conduits are sometimes referred to as introducer sheaths. Advances continue to be made to minimize the size of the incision required for a catheter or other medical device to be advanced into the body and to minimize trauma to the patient as the catheter or medical device is advanced through the patient's vasculature. However, in some instances, to effectively treat a patient's condition, a relatively large object must be inserted through the incision and advanced through the vasculature to the treatment site. In such instances, it may not be possible to reduce the profile or cross-section of the medical device, but it may be possible to configure an introducer sheath that helps minimize trauma to the patient's anatomy during a medical procedure.

[0005] Definitions and Terminology This disclosure is not intended to be read in a restrictive manner, for example, the terms used in this application should be read broadly with respect to the meaning that terms of the art ascribe to such terms.

[0006] With respect to the term imprecision, "about" and "approximately" are used interchangeably to refer to measurements, including the stated measurements, and may include measurements that are reasonably close to the stated measurements. Measurements that are reasonably close to the stated measurements deviate from the stated measurements by a reasonably small amount, as would be understood and readily ascertained by one of ordinary skill in the relevant art. Such deviations may result from measurement errors, differences in calibration of measuring and / or manufacturing equipment, human error in reading and / or setting measurements, minor adjustments made to optimize performance and / or construction parameters given differences in measurements relative to other components, specific implementation scenarios, imprecise adjustment and / or manipulation of objects by humans or machines, and the like. In cases where it is determined that such reasonably small differences cannot be readily ascertained by one of ordinary skill in the relevant art, the terms "about" and "approximately" may be understood to mean ±10% of the stated value.

[0007] As used herein, the term "controlled shrinkage" refers to shortening the length of an article in at least one direction by application of heat, wetting with a solvent, or other suitable means or a combination thereof, in a manner that inhibits folds, pleats, or wrinkles in the resulting article that are visible to the naked eye.

[0008] As used herein, the term "elastic" refers to the ability of a material or article to spontaneously recover or return to approximately its original dimensions after contraction, expansion, elongation, or other strain upon removal of the contraction, expansion, elongation, or other straining force. As used herein, the term "inelastic" refers to the inability of a material or article to spontaneously recover or return to approximately its original dimensions after contraction, expansion, elongation, or other strain upon removal of the contraction, expansion, elongation, or other straining force.

[0009] The term "smooth" as used herein in the context of texture or surface features means free of wrinkles, folds, creases, pleats, and similar surface features that are visible to the naked eye without the aid of magnification along a particular portion or region of the surface. A "major portion" of a surface of an article (e.g., an inner or outer surface of a tubular member) is smooth when more than 50% of the surface is smooth. "Substantially all" of a surface of an article (e.g., an inner or outer surface) is smooth when 90% or more of the surface is smooth. And an "entire surface" of an article (e.g., an inner or outer surface) is smooth when the entire surface is smooth. As a non-limiting example, a major portion of a surface is smooth, where more than 50% of the surface is smooth when measured along a major dimension (e.g., length) of the article (e.g., a tubular member 10 cm long is free of wrinkles along more than 5 cm of the length of the tubular member). Similarly, and as another non-limiting example, substantially all surfaces of the article are smooth, where 90% or more of the surface is smooth when measured along a major dimension (e.g., length) of the article (e.g., a tubular member having a length of 10 cm is wrinkle-free along at least 9 cm of the length of the tubular member).

[0010] For purposes of this disclosure, a component is considered "wrinkle-free" if, within a 1 cm length of the component, the surface of the component is devoid of wrinkles, folds, creases, pleats, and similar surface features that are visible to the naked eye without the aid of magnification. Note that the terms "free of folds," "devoid of folds," and "fold free" are used interchangeably herein. Summary of the Invention

[0011] Abstract According to one example ("Example 1"), a medical device includes a frame including a plurality of strut elements arranged to form a tubular framework, and a covering extending along a portion of the frame, the frame and the covering extending to define a sheath having a lumen extending therethrough, the strut elements of the frame interacting with each other to provide the sheath with axial compression resistance and hoop strength, the lumen having a length, the sheath being radially expandable such that a diameter of the lumen is operable to expand from an initial diameter to an expanded diameter greater than the initial diameter to accommodate passage of one or more devices therethrough, and the sheath further configured to self-recover the diameter of the lumen along the length of the sheath to a post-delivery diameter less than the expanded diameter in response to the one or more devices being removed from the lumen.

[0012] According to another example ("Example 2"), in addition to the medical device of Example 1, the covering is configured to stretch such that the sheath is radially expandable, the covering stores potential energy when the lumen of the sheath is expanded to the expanded diameter, and the potential energy of the covering can be converted to kinetic energy, thereby causing the sheath to self-restore the diameter of the lumen to a post-delivery diameter.

[0013] According to another example ("Example 3"), in addition to any of the medical devices of the above examples, the medical device includes one of an elastomeric material and an elastomer present within the pores of the covering, whereby the elastomeric material or elastomer stores potential energy when the lumen of the sheath is expanded to an expanded diameter, and the potential energy of the elastomeric material or elastomer is convertible to kinetic energy, whereby the sheath self-restores the diameter of the lumen to a post-delivery diameter. According to another example ("Example 4"), in addition to any of the examples above, the frame is configured to store potential energy when the sheath is expanded to an expanded diameter, and the potential energy of the frame can be converted to kinetic energy, thereby causing the sheath to self-restore the diameter of the lumen to a post-delivery diameter.

[0014] According to another example ("Example 5"), in addition to the medical device of Example 4, the frame is configured to an initial configuration in which the lumen of the sheath has an initial diameter.

[0015] According to another example ("Example 6"), in addition to the medical devices of Examples 1-4, the frame is shaped into an initial configuration in which the diameter of the lumen of the sheath is greater than the initial diameter, such that when the lumen of the sheath has the initial diameter, the frame stores potential energy.

[0016] According to another example ("Example 7"), in addition to the medical device of Example 6, the covering stores potential energy when the lumen of the sheath has an initial diameter, and wherein a first force associated with the potential energy of the covering and a second force associated with the potential energy of the frame are in equilibrium with each other when the lumen of the sheath has the initial diameter and when the lumen of the sheath has a post-delivery diameter.

[0017] According to another example ("Example 8"), further to any of the medical devices of the above examples, the post-delivery diameter and the initial diameter are substantially the same.

[0018] According to another example ("Example 9"), further to any of the medical devices of the above examples, said post-delivery diameter is 115% or less of the initial diameter.

[0019] According to another example ("Example 10"), in addition to the medical device of any of Examples 5-9, the frame is heat set into an initial configuration.

[0020] According to another example ("Example 11"), in addition to any of the medical devices of Examples 6-10, when the lumen of the sheath has an initial diameter, the frame biases the sheath with a radially outward vector.

[0021] According to another example ("Example 12"), in addition to any of the medical devices of Examples 6-10, when the lumen of the sheath has an initial diameter, the covering biases the sheath with a radially inward vector.

[0022] According to another example ("Example 13"), in addition to any of the medical devices of the above examples, the frame is blood-permeable and the covering is blood-impermeable, such that the sheath is blood-impermeable.

[0023] According to another example ("Example 14"), in addition to any of the medical devices of the previous examples, the sheath is configured to expand uniformly in a radial direction.

[0024] According to another example ("Example 15"), in addition to any of the medical devices of the previous examples, the covering extends along an interior of the frame to define a luminal wall of the lumen.

[0025] According to another example ("Example 16"), in addition to any of the medical devices of the previous examples, the covering comprises ePTFE.

[0026] According to another example ("Example 17"), in addition to any of the medical devices of the above examples, the covering is an ePTFE tube that is everted over the end of the frame such that the ePTFE tube extends along the inside and outside of the frame to the proximal end of the frame.

[0027] According to another example ("Example 18"), in addition to any of the medical devices of the above examples, the sheath is configured such that when the lumen is at an initial diameter, the sheath has a smooth outer surface.

[0028] According to another example ("Example 19"), in addition to any of the medical devices of the above examples, the sheath is configured such that when the lumen is expanded to an expanded diameter, the sheath has a smooth outer surface.

[0029] According to another example ("Example 20"), in addition to any of the medical devices of the above examples, the sheath is configured to have a smooth outer surface when the sheath self-recovers the diameter of the lumen to a post-delivery diameter.

[0030] According to another example ("Example 21"), further to any of the medical devices of the previous examples, a plurality of struts of the frame form one or more helical and diamond apertures.

[0031] According to another example ("Example 22"), in addition to any of the medical devices of the previous examples, the plurality of struts of the frame define at least two circumferentially adjacent closed cells.

[0032] According to another example ("Example 23"), in addition to any of the medical devices of the previous examples, the frame comprises a metal alloy.

[0033] According to another example ("Example 24"), in addition to the medical device of Example 23, the frame includes Nitinol.

[0034] According to another example ("Example 25"), in addition to any of the medical devices of Examples 1-22, the frame comprises a polymer.

[0035] According to another example ("Example 26"), in addition to any of the medical devices of the previous examples, the frame is monolithic.

[0036] According to another example ("Example 27"), in addition to any of the medical devices of the previous examples, the frame is a laser cut tube.

[0037] According to another example ("Example 28"), in addition to any of the above examples of the medical device, the covering forms a lubricious impermeable layer of the sheath.

[0038] According to another example ("Example 29"), in addition to any of the medical devices of the previous examples, the kinkability of the frame is less than the kinkability of the covering.

[0039] According to another example ("Example 30"), in addition to any of the medical devices of the above examples, the sheath is an introducer sheath and the lumen is a working lumen configured to provide passage of one or more devices through the introducer sheath.

[0040] According to another example ("Example 31"), in addition to any of the medical devices of the above examples, the sheath is configured such that the expanded diameter of the lumen is within the range of one hundred percent (100%) to two hundred percent (200%) of the initial diameter.

[0041] According to another example ("Example 32"), in addition to any of the medical devices of the above examples, a plurality of distinct zones are defined along an axial length of the sheath, and the sheath is configured to progressively expand and self-recover such that a diameter of the lumen at a first zone of the plurality of distinct zones is expandable relative to a diameter of the lumen at a second zone of the plurality of distinct zones, and a diameter of the lumen at the first zone is self-recoverable to a post-delivery diameter relative to the second zone.

[0042] According to another example ("Example 33"), in addition to any of the medical devices of Examples 1-32, the diameter of the lumen is configured to be expandable to an expanded diameter at a first cross-section along the axial length of the sheath without causing an expansion of the diameter of the lumen from an initial diameter at a second cross-section along the axial length of the sheath, and the diameter of the lumen is configured to be self-recoverable to a post-delivery diameter at the first cross-section without causing a decrease in the diameter of the lumen at the second cross-section.

[0043] According to another example ("Example 34"), in addition to the medical device of any of Examples 1-33, the sheath includes a lubricious liner layer configured to provide a lubricious inner surface when the sheath lumen is at an initial diameter and when the sheath lumen is expanded to an expanded diameter.

[0044] According to another example ("Example 35"), in addition to any of the medical devices of Examples 1 to 33, the sheath is configured such that an inner surface of the sheath is smooth and an outer surface of the sheath is smooth both when the sheath is at an initial diameter and when the sheath is expanded to an expanded diameter.

[0045] According to another example ("Example 36"), a delivery system includes a delivery catheter having a distal end portion, an expandable sheath having a lumen extending through the expandable sheath, where the lumen has a length and the expandable sheath is radially expandable such that a diameter of the lumen is operable to expand from an initial diameter to an expanded diameter greater than the initial diameter, and an in-line sheath dilator configured to receive the delivery catheter and releasably couple to a distal end portion of the delivery catheter, where the in-line sheath dilator and the delivery catheter are slidably insertable through a lumen of the expandable sheath and configured to expand the expandable sheath from the initial diameter to an expanded diameter, where the distal end portion of the delivery catheter is extendable from the in-line sheath dilator after the expandable sheath is expanded to an expanded diameter by the in-line sheath dilator and maintaining the expandable sheath at the expanded diameter.

[0046] According to another example ("Example 37"), in addition to the delivery system of Example 36, the expandable sheath includes a frame including a plurality of strut elements arranged to form a tubular framework, and a covering extending along a portion of the frame, the strut elements of the frame interacting with each other to provide the expandable sheath with axial compression resistance and hoop strength.

[0047] According to another example ("Example 38"), in addition to the delivery system of Examples 36 or 37, the in-line sheath expander is configured to reconnect with the distal end portion of the delivery catheter after extending the distal end portion of the delivery catheter from the in-line sheath expander after expanding the expandable sheath to an expanded diameter.

[0048] According to another example ("Example 39"), in addition to the delivery system of any one of Examples 36-38, the expandable sheath is further configured to self-restore the diameter of the lumen along a length of the expandable sheath to a post-delivery diameter smaller than the expanded diameter in response to the in-line sheath expander and the delivery catheter being removed from the lumen.

[0049] According to another example ("Example 40"), in addition to the delivery system of any one of Examples 36-39, the delivery system includes one or more devices coupled to the delivery catheter proximate a distal end portion of the delivery catheter.

[0050] According to another example ("Example 41"), in addition to the delivery system of Example 40, the one or more devices include a mitral valve or an aortic valve prosthesis.

[0051] According to another example ("Example 42"), in addition to the delivery system of any one of Examples 36-41, the in-line sheath dilator includes a proximal opening, a distal opening, and a dilator lumen extending therethrough, the dilator lumen configured to slidably receive the delivery catheter, and the distal opening has a larger diameter than the proximal opening.

[0052] According to another example ("Example 43"), in addition to the delivery system of any one of Examples 36-42, an outer surface of the in-line sheath expander comprises a lubricious material and an inner surface of the expandable sheath comprises a radially expandable elastomer.

[0053] According to another example ("Example 44"), in addition to the delivery system of Example 43, the lubricious material includes PTFE, high density polyethylene (HDPE), polyimide, or a thermoplastic with a hydrophilic coating.

[0054] According to another example ("Example 45"), in addition to the delivery system of Examples 43 or 44, the radially expandable elastomer comprises silicone, polyurethane, thermoplastic elastomer (TPE), or thermoplastic vulcanizate (TPV).

[0055] According to another example ("Example 46"), in addition to the delivery system of any one of Examples 36 to 45, the sheath includes a lubricious liner layer configured to reduce friction between an outer surface of the in-line sheath expander and an inner surface of the expandable sheath.

[0056] According to another example ("Example 47"), in addition to the delivery system of Example 46, the lubricious liner layer is configured to provide a lubricious inner surface when the lumen is at its initial diameter and when the lumen is expanded to its expanded diameter.

[0057] According to another example ("Example 48"), in addition to the delivery system of any one of Examples 36 to 47, the sheath is configured to provide a smooth inner surface and a smooth outer surface both when the sheath is at an initial diameter and when the sheath is expanded to an expanded diameter.

[0058] According to another example ("Example 49"), in addition to the delivery system of Example 46, the lubricious liner layer is formed as an inelastic pleated elongated tubular member.

[0059] According to another example ("Example 50"), in addition to the delivery system of Example 39 or any one of Examples 40 to 49 in addition to Example 39, the covering is configured to stretch the expandable sheath so that it is radially expandable, wherein the covering stores potential energy when the lumen of the expandable sheath is expanded to an expanded diameter, and the potential energy of the covering is convertible into kinetic energy that causes the expandable sheath to self-restore the diameter of the lumen to a post-delivery diameter.

[0060] According to another example ("Example 51"), in addition to the delivery system of Example 39 or any one of Examples 40 to 51 in addition to Example 39, one of an elastomeric material and an elastomer is present within the pores of the covering such that when the lumen of the expandable sheath is expanded to an expanded diameter, the elastomeric material or elastomer stores potential energy, and the potential energy of the elastomeric material or elastomer can be converted into kinetic energy that causes the expandable sheath to self-restore the diameter of the lumen to a post-delivery diameter.

[0061] According to another example ("Example 52"), the delivery system of Example 39, or any one of Examples 40 to 51 in addition to Example 39, the frame is configured to store potential energy when the expandable sheath is expanded to an expanded diameter, and the potential energy of the frame can be converted into kinetic energy that causes the expandable sheath to self-restore the diameter of the lumen to a post-delivery diameter.

[0062] According to another example ("Example 53"), in addition to the delivery system of Example 52, the frame is configured to an initial configuration in which the lumen of the expandable sheath has an initial diameter.

[0063] According to another example ("Example 54"), in addition to the delivery system of Example 39, or any one of Examples 40 to 52 in addition to Example 39, the frame is shaped into an initial configuration in which the diameter of the lumen of the expandable sheath is larger than the initial diameter, such that the frame stores potential energy when the lumen of the expandable sheath has the initial diameter.

[0064] According to another example ("Example 55"), in addition to the delivery system of Example 54, the covering stores potential energy when the lumen of the expandable sheath has an initial diameter, and a first force associated with the potential energy of the covering and a second force associated with the potential energy of the frame are in equilibrium with each other when the lumen of the expandable sheath has an initial diameter and when the lumen of the expandable sheath has a post-delivery diameter.

[0065] According to another example ("Example 56"), in addition to the delivery system of any one of Examples 39-55, the post-delivery diameter and the initial diameter are substantially the same.

[0066] According to another example ("Example 57"), in addition to the delivery system of any one of Examples 39-56, the post-delivery diameter is 115% or less of the initial diameter.

[0067] According to another example ("Example 58"), in addition to the delivery system of any one of Examples 53-57, the frame is heat set in the initial configuration.

[0068] According to another example ("Example 59"), in addition to the delivery system of Example 37, any one of Examples 51 to 58, when the lumen of the expandable sheath has an initial diameter, the frame biases the expandable sheath in a radially outward vector.

[0069] According to another example ("Example 60"), in addition to Example 37, in addition to any one of Examples 51 to 58, when the lumen of the expandable sheath has an initial diameter, the covering biases the expandable sheath in a radially inward vector.

[0070] According to another example ("Example 61"), in addition to the delivery system of Example 37, any one of Examples 51 to 60, the frame is blood-permeable and the covering is blood-impermeable such that the expandable sheath is blood-impermeable.

[0071] According to another example ("Example 62"), in addition to the delivery system of any one of Examples 36-61, the expandable sheath is configured to expand uniformly in a radial direction.

[0072] According to another example ("Example 63"), in addition to the delivery system of Example 37, or in addition to Example 37 and any one of Examples 38-62, the covering extends along the interior of the frame to define a lumen wall.

[0073] According to another example ("Example 64"), in addition to the delivery system of Example 37, or in addition to Example 37 and any one of Examples 38-63, the covering comprises ePTFE.

[0074] According to another example ("Example 65"), in addition to the delivery system of Example 63, the covering is an ePTFE tube that is inverted over the end of the frame so that the ePTFE tube extends along the inside and outside of the frame to the proximal end of the frame.

[0075] According to another example ("Example 66"), in addition to any one of the delivery systems of Examples 36 to 65, the expandable sheath is configured such that when the lumen is at an initial diameter, the expandable sheath has a smooth outer surface.

[0076] According to another example ("Example 67"), in addition to any one of the delivery systems of Examples 36 to 66, the expandable sheath is configured such that when the lumen is expanded to an expanded diameter, the expandable sheath has a smooth outer surface.

[0077] According to another example ("Example 68"), in addition to any one of the delivery systems of Examples 39 to 67, the expandable sheath is configured such that when the expandable sheath self-recovers the diameter of the lumen to a post-delivery diameter, the expandable sheath has a smooth outer surface.

[0078] According to another example ("Example 69"), in addition to the delivery system of Example 37, or in addition to Example 37, any one of Examples 38 to 68, a plurality of struts of the frame form one or more spiral and diamond openings.

[0079] According to another example ("Example 70"), in addition to the delivery system of Example 37, or in addition to Example 37 and any one of Examples 38-69, the struts of the frame define at least two circumferentially adjacent closed cells.

[0080] According to another example ("Example 71"), in addition to the delivery system of Example 37, or Example 37 plus any one of Examples 38-70, the frame comprises a metal alloy.

[0081] According to another example ("Example 72"), in addition to the delivery system of Example 71, the frame includes Nitinol.

[0082] According to another example ("Example 73"), in addition to the delivery system of Example 37, or Example 37 plus any one of Examples 38-70, the frame comprises a polymer.

[0083] According to another example ("Example 74"), in addition to the delivery system of Example 37, or Example 37 plus any one of Examples 38-73, the frame is monolithic.

[0084] According to another example ("Example 75"), in addition to the delivery system of Example 37, or Example 37 plus any one of Examples 38-74, the frame is a laser cut tube.

[0085] According to another example ("Example 76"), in addition to the delivery system of Example 37, or in addition to Example 37, to the delivery system of any one of Examples 38-75, the covering forms a lubricious, impermeable layer of the sheath.

[0086] According to another example ("Example 77"), in addition to the delivery system of Example 37, or in addition to Example 37, any one of Examples 38 to 76, the kinkability of the frame is less than the kinkability of the covering.

[0087] According to another example ("Example 78"), in addition to the delivery system of any one of Examples 36 to 77, the expandable sheath is an introducer sheath, and the lumen is a working lumen configured to provide passage of one or more devices through the introducer sheath.

[0088] According to another example ("Example 79"), in addition to any one of the delivery systems of Examples 36-78, the expandable sheath is configured such that the expanded diameter of the lumen is within the range of one hundred percent (100%) to two hundred percent (200%) of the initial diameter.

[0089] According to another example ("Example 80"), in addition to the delivery system of any one of Examples 39 to 79, a plurality of distinct zones are defined along an axial length of the expandable sheath, and the expandable sheath is configured to progressively expand and self-recover such that a diameter of the lumen at a first zone of the plurality of distinct zones is expandable relative to a diameter of the lumen at a second zone of the plurality of distinct zones, and a diameter of the lumen at the first zone is self-recoverable to a post-delivery diameter relative to the second zone.

[0090] According to another example ("Example 81"), in addition to any one of Examples 39 to 80, the diameter of the lumen is configured to be expandable to an expanded diameter at a first cross-section along the axial length of the expandable sheath without causing an expansion of the diameter of the lumen from an initial diameter at a second cross-section along the axial length of the expandable sheath, and the diameter of the lumen is configured to be self-recoverable to a post-delivery diameter at the first cross-section without causing a decrease in the diameter of the lumen at the second cross-section.

[0091] According to another example ("Example 82"), a method of placing a transcatheter medical device within a body includes advancing an in-line sheath dilator over at least a portion of a delivery catheter with one or more devices restrained in a distal end portion of the delivery catheter; coupling the in-line sheath dilator to the distal end portion of the delivery catheter to cover the one or more devices; advancing an expandable sheath into a body vasculature; advancing the delivery catheter and the in-line sheath dilator into the expandable sheath such that the distal end portion of the delivery catheter is adjacent to the distal end of the expandable sheath, wherein advancing the in-line sheath dilator into the expandable sheath causes the expandable sheath to expand from an initial diameter to an expanded diameter that is greater than the initial diameter; and decoupling the in-line sheath dilator from the distal end portion of the delivery catheter and extending the delivery catheter from the in-line sheath dilator while maintaining the expandable sheath at the expanded diameter with the in-line sheath dilator.

[0092] According to another example ("Example 83"), further to Example 82, the method includes advancing the delivery catheter into the vasculature to deliver the one or more devices to a desired location, positioning the one or more devices at the desired location, then retracting the delivery catheter from the vasculature, and decoupling the in-line sheath expander from the expandable sheath, and then recoupling the in-line sheath expander to a distal end portion of the delivery catheter.

[0093] According to another example ("Example 84"), further to Example 83, the method includes retracting the in-line sheath expander and the delivery catheter from the lumen of the expandable sheath and causing the expandable sheath to self-restore the diameter of the lumen along a length of the expandable sheath to a post-delivery diameter that is smaller than the expanded diameter.

[0094] According to another example ("Example 85"), in addition to any one of Examples 82-84, an outer surface of the in-line sheath expander is smoother than an inner surface of the expandable sheath.

[0095] According to another example ("Example 86"), in addition to any one of Examples 82-85, friction between an outer surface of the in-line sheath expander and an inner surface of the expandable sheath is reduced by a lubricious liner layer bonded to the inner surface of the expandable sheath, and further, advancing the delivery catheter and the in-line sheath expander into the expandable sheath includes expanding the lubricious liner layer from an initial diameter to an expanded diameter greater than the initial diameter.

[0096] According to another example ("Example 87"), in addition to Example 86, the lubricious liner layer is formed as an elastic elongated tubular member.

[0097] According to another example ("Example 88"), in addition to Example 86, the lubricious liner layer is formed as a pleated elongated tubular member.

[0098] While multiple embodiments are disclosed, still other embodiments will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. [Brief description of the drawings]

[0099] BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate embodiments and, together with the description, serve to explain the principles of the disclosure.

[0100] [Figure 1] FIG. 1 is an illustration of a medical system including an expandable introducer sheath according to one embodiment.

[0101] [Diagram 2]FIG. 2 is a detailed view of a distal end of an expandable introducer sheath of the medical system of FIG. 1 according to one embodiment.

[0102] [Diagram 3] FIG. 3 is a detailed view of a distal end of the expandable introducer sheath of the medical system of FIG. 1 according to one embodiment.

[0103] [Figure 3A] 3A is a cross-sectional view of the expandable introducer sheath of FIG. 3 taken along line 3A-3A.

[0104] [Figure 4] FIG. 4 is a diagram of a support framework of an expandable introducer sheath according to one embodiment.

[0105] [Diagram 5] FIG. 5 is a diagram of a support framework of an expandable introducer sheath according to one embodiment.

[0106] [Figure 6] FIG. 6 is an illustration of a medical system including a partially expanded expandable introducer sheath according to one embodiment.

[0107] [Figure 7] FIG. 7 is an illustration of a medical instrument including an in-line sheath expander disposed on a delivery catheter carrying a medical device mounted proximate a distal end portion of the delivery catheter according to one embodiment.

[0108] [Figure 8] FIG. 8 is a diagram of the medical instrument of FIG. 7 with the medical device in a compacted configuration.

[0109] [Figure 9] FIG. 9 is an illustration of the medical device of FIG. 8 with an in-line sheath dilator positioned over the medical device.

[0110] [Figure 10] FIG. 10 is an illustration of a medical device including an expandable sheath positioned along a guidewire with the aid of a dilator, according to one embodiment.

[0111] [Figure 11] FIG. 11 is a diagram of the medical device of FIG. 10 with the dilator removed.

[0112] [Figure 12] 12 is a diagram of the medical device of FIG. 11, the medical device shown in FIG. 9 being advanced along a guidewire toward an expandable sheath.

[0113] [Figure 13] FIG. 13 is a diagram of the medical device of FIG. 12 with an in-line sheath expander inserted into the expandable sheath to expand the expandable sheath.

[0114] [Figure 14] FIG. 14 is a diagram of the medical device of FIG. 13 with the delivery catheter extended from the in-line sheath dilator.

[0115] [Figure 15] FIG. 15 is a diagram of the medical apparatus of FIG. 14 according to one embodiment, with the distal end portion of the delivery catheter shown carrying a medical device for placement at a target site in a patient's body.

[0116] [Figure 16] FIG. 16 is a diagram of the medical apparatus of FIG. 14 after deployment of the medical device.

[0117] [Figure 17] FIG. 17 is a diagram of the medical device of FIG. 16 with the delivery catheter retracted into the in-line sheath dilator.

[0118] [Figure 18] FIG. 18 is a diagram of the medical device of FIG. 17 with the in-line sheath dilator retracted from the expandable sheath.

[0119] [Figure 19] FIG. 19 is a diagram of the medical device of FIG. 18 after the expandable sheath has been retracted from the patient's body, according to one embodiment.

[0120] [Figure 20A] FIG. 20A is a diagram of an expandable sheath with a non-elastic lubricious liner in pleated and non-pleated configurations, according to one embodiment. [Figure 20B] FIG. 20B is a diagram of an expandable sheath with a non-elastic lubricious liner in pleated and non-pleated configurations, according to one embodiment.

[0121] [Figure 21A] 21A and 21B are diagrams of an expandable sheath with a non-elastic lubricious liner in pleated and non-pleated configurations, according to one embodiment. [Figure 21B] FIG. 21B is a diagram of an expandable sheath with a non-elastic lubricious liner in pleated and non-pleated configurations, according to one embodiment.

[0122] [Figure 22A] FIG. 22A is a diagram of an expandable sheath in a compressed configuration and an expanded configuration, according to one embodiment. [Figure 22B] FIG. 22B is a diagram of an expandable sheath in a compressed configuration and an expanded configuration, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0123] Detailed Description Those skilled in the art will readily appreciate that the various aspects of the present disclosure may be implemented by any number of methods and devices configured to perform the intended functions. In other words, other methods and devices may be incorporated herein to perform the intended functions. It should also be noted that the accompanying drawings referenced herein are not necessarily drawn to scale and may be exaggerated to illustrate various aspects of the present disclosure, and in that regard, the drawings should not be construed as limiting.

[0124] The embodiments herein include various devices, systems, and methods for an expandable introducer sheath, including, but not limited to, an introducer sheath for use in connection with a medical procedure, such as an endovascular procedure. Thus, the embodiments discussed herein include an endovascular introducer sheath for providing minimally invasive access to various regions of a patient's vasculature, such as the aorta. The introducer sheath is generally tubular and includes a proximal end, a distal end, and a central through lumen. The introducer sheath is configured to be expandable in situ (e.g., while stretching within the patient's anatomy) and adapted to contract in situ (e.g., self-heal) after expansion. For example, in various embodiments, the introducer sheath is adapted to be expanded from an initial diameter to a larger expanded diameter (also referred to herein as an expanded diameter) to accommodate the passage of one or more medical devices through the lumen of the introducer sheath. The introducer sheath is also adapted to be capable of self-healing from the larger expanded diameter to a diameter smaller than the larger expanded diameter. That is, in various embodiments, the introducer sheath of the present disclosure is adapted to self-recover from a larger expanded diameter to a smaller diameter without requiring an external force for such recovery.

[0125] In various examples, the introducer sheath is circumferentially expandable in response to outward pressure applied from within the lumen of the introducer sheath. By so expanding and contracting, the introducer sheath of the present disclosure is operable to maintain a reduced profile or cross-sectional area, thereby minimizing trauma to the surrounding anatomical structures within which it is located. The operation of the introducer sheath of the present disclosure is also such that the introducer sheath serves as a support surface between a medical device and the patient's anatomical structure, such as the patient's vessel wall in which the introducer sheath is disposed. As such a support surface, a medical device passing through the lumen of the introducer sheath does not, for example, directly contact the vessel wall. Although some conventional introducer sheaths may be configured to deploy to a larger diameter, for example, such conventional devices do not recover to a smaller diameter than the deployed, larger diameter after expansion.

[0126] 1 is a perspective view of a medical system 10. As shown, the medical system 10 includes an introducer sheath 1000. In various examples, the medical system 10 can optionally include one or more auxiliary components 2000, which can include, but are not limited to, control handles, valves such as hemostasis valves, hubs configured to facilitate passage of instruments, and connectors, such as luer fittings (e.g., Tuohy-Borst connectors), that are used to control backflow of fluids through one or more components of the medical system 10.

[0127] The introducer sheath 1000 of the medical system 10 is an elongate element having a proximal end 1002, a distal end 1004, and a lumen 1006. The lumen 1006 extends through the introducer sheath 1000 from the proximal end 1002 to the distal end 1004, such that the proximal and distal ends 1002 and 1004, respectively, are open to the lumen 1006. FIG. 2 is a detailed view of a distal portion of the introducer sheath 1000, showing the lumen 1006 being open at the distal end 1004 of the introducer sheath 1000. In various embodiments, the lumen 1006 is configured to facilitate the passage of one or more medical devices through the introducer sheath 1000. Thus, the lumen 1006 is configured to accommodate such medical devices. In various examples, as discussed further below, the introducer sheath 1000 is configured such that the diameter of the lumen 1006 can be expanded to accommodate such medical device. In some examples, the lumen 1006 is configured to expand incrementally along the length of the introducer sheath 1000 to accommodate the medical device as it advances distally through the lumen 1006. This incremental expansion of the lumen 1006 can be continuous or stepwise, as discussed further below. For example, the introducer sheath 1000 can have an outer introducing diameter in the range of 3 to 20 French (Fr) and a working length in the range of 40 cm to 200 cm. For example, the introducer sheath 1000 can have a working length of 75 cm to 150 cm. In some examples, the outer introducing diameter can be 5 Fr to 10 Fr. In some such instances, the introducer sheath 1000 is configured to expand to allow instruments ranging up to 30 Fr to pass through the lumen 1006 of the introducer sheath 1000. It is understood, therefore, that the outer diameter of the introducer sheath 1000 will expand to diameters greater than 30 Fr under such conditions. In some instances, the introducer sheath 1000 can be expandable to outer diameters of 3 Fr to 30 Fr or more.

[0128] 3 , the introducer sheath 1000 generally includes a support framework 1100 and a covering 1200. The support framework 1100 is adapted to support the covering 1200 and provide one or more of axial compressive strength and hoop strength to the introducer sheath 1000. In some instances, the support framework 1100 operates to minimize kinking of the introducer sheath 1000. For example, in some instances, the kinking of the support framework is less than the kinking of the covering 1200.

[0129] The covering 1200 is configured to isolate the lumen 1006 of the introducer sheath 1000 and help at least partially define a barrier between the interior of the introducer sheath 1000 and the exterior of the introducer sheath 1000. In some instances, the covering 1200 helps isolate the support framework 1100 from one or more of the patient's vasculature through which the medical device is advanced. Such isolation helps minimize the likelihood that a medical device being advanced through the lumen 1006 of the introducer 1000 will become entangled with the support framework 1100. In some instances, the covering 1200 optionally defines a lubricious layer that helps reduce friction between the introducer sheath 1000 and one or more of the patient's vasculature through which the medical device is advanced.

[0130] 4 provides an exemplary diagram of the support framework 1100. The support framework 1100, in combination with the covering 1200, may be configured to cause the introducer sheath 1000 to adopt an initial profile or configuration in which the lumen 1006 of the introducer sheath 1000 has an initial diameter when no external forces are acting on the introducer sheath 1000. In such an example, the initial outer diameter of the introducer sheath 1000 is generally one that is configured for insertion into a patient's vasculature (e.g., 3 Fr to 20 Fr).

[0131] The support framework 1100 is also configured to be expandable to facilitate expansion of one or more portions of the introducer sheath 1000 from an initial configuration to an expanded configuration in which the lumen of the introducer sheath 1000 has a diameter greater than the initial diameter. These initial or contracted configurations and expanded or expanded configurations can include a variety of shapes, including circular and non-circular profiles (e.g., elliptical, etc.). The support framework 1100 can be formed from an elastic or resilient material that allows the framework to elastically deform according to the initial and expanded configurations described above.

[0132] As shown, the support framework 1100 generally comprises a tubular member having a proximal end 1102 and a distal end 1104 and a through lumen 1106. The support framework includes a plurality of strut elements 1108 located between the proximal and distal ends 1102 and 1104. In various examples, one or more strut elements 1108 intersect one another at intersections or nodes 1110. As shown, the interconnected strut elements 1108 define one or more closed cells 1112. In some examples, the closed cells are diamond shaped, although other shapes are contemplated. In some examples, adjacent closed cells 1112 share a common intersection or node 1110, as shown in FIG. 4. In some examples, the intersections or nodes 1110 at the respective proximal and distal ends of each cell define vertices 1116.

[0133] In some examples, the closed cells 1112 can define one or more rows 1114 of cells. When the support framework 1100 includes multiple rows of closed cells 1112, adjacent rows of closed cells (e.g., longitudinally adjacent rows) can be directly or indirectly coupled to one another. Direct couplings between adjacent rows 1114 generally occur at vertices 1116 where adjacent rows 1114 intersect one another. Indirect couplings can include one or more longitudinal connectors that operate to couple adjacent rows 1114 together. In various examples, such longitudinal connectors can extend between vertices of adjacent rows 1114 or can extend between other portions of the strut elements 1108, such as midpoints between the ends of the strut elements 1108.

[0134] In some examples, in addition to or instead of the closed cells 1112, the interconnected struts can define one or more circumferential members and / or helical elements having undulations, as shown in FIG. 5. The undulations can be formed by the interconnected struts at bends or vertices and can be arranged in a wave-like configuration. The undulations can form a variety of patterns, such as a sinusoidal pattern, a zigzag pattern, or similar geometric patterns. The undulations of the helical elements can form a series of rows or turns along the length of the support framework.

[0135] 5 shows a support framework 1300 comprising a tubular body 1302, according to one embodiment. The support framework 1300 can be manufactured in a variety of configurations, including a variety of lengths and inner diameters.

[0136] The continuous pattern of undulations 1306 forms a series of helical turns about the longitudinal axis along line BB shown in Figures 3 and 5. The helical turns 1321, 1322 can form a substantially cylindrical tubular helical element 1320. The helical turns 1321, 1322 have several vertices 1323. These vertices 1323 are formed where two or more struts 1324 interconnect. In Figure 5, the helical element 1320 can be axially inserted between and directly connected to the proximal and distal rows of closed cells (see, e.g., Figure 4). Various connecting struts 1325 can be provided to contribute to the longitudinal stability of the stent. For example, these connecting struts or connectors can connect adjacent structures, turns or rows of the support framework 1300, as similarly described above with reference to the support framework 1100.

[0137] The support framework (e.g., 1100 and / or 1300) can be made from a wide variety of materials or combinations of materials, including metals and plastics. Metals that can be used include stainless steel, titanium, tantalum, alloys such as Elgiloy® and Phynox® spring alloys, 316 stainless steel, MP35N® alloy, and Nitinol nickel-titanium alloy. Superelastic or shape memory forms of the above alloys can also be used. The use of Nitinol alloys can impart biasing properties to the support framework. In such Nitinol support frameworks, the phase behavior of the material can be selected and the support framework is treated to tend to influence the introducer sheath 1000 to adopt an initial configuration, one or more expanded configurations, or some configuration in between. Suitable plastics can include PEEK, PEBAX, PTFE, nylon, polyethylene, and the like.

[0138] In various examples, any technique that produces a support framework (e.g., 1100 and / or 1300) with the required characteristics can be used. For example, the support framework can be cut into the desired pattern from a continuous tube of material (e.g., Nitinol), such as by using a laser. Thus, in some such examples, the support framework forms a monolithic structure or unibody. The support framework can also be manufactured by various known techniques, such as machining, chemical etching, laser ablation, die cutting, plasma etching, stamping, water jet cutting, or other suitable means, so long as the required support framework and associated material properties can be achieved. The support framework can also be formed from flat sheets of material that are cut into the desired pattern and then bonded together to form a tube with a seam. Finally, the support framework can be manufactured from wires or ribbons that are processed into the desired shape and then bonded together, such as by welding, into the final pattern.

[0139] As described above, in various embodiments, the introducer sheath 1000 includes a covering 1200. The covering 1200 may be provided on the inner or outer surface, or both, of the support framework 1100, as shown in FIG. 2. In various examples, the covering 1200 generally includes a membrane that is reinforced with one or more materials to provide the covering 1200 with elastomeric properties. Such elastomeric properties provide that the covering 1200 is adapted to elastically stretch upon expansion of the introducer sheath 1000. In some examples, the membrane 1200 is porous or otherwise includes a plurality of void spaces. In some examples, the covering 1200 includes one layer of a reinforced membrane and another layer that is not reinforced.

[0140] Suitable membrane materials for covering 1200 include, but are not limited to, polymers such as olefins, PEEK, polyamides, polyurethanes, polyesters, e.g., polyethylene terephthalate (PET), polyethylene, polypropylene, polyurethanes, silicones, fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), and fluoroelastomers such as tetrafluoroethylene / polymethylvinylether (TFE / PMVE) copolymers. In a preferred embodiment, the membrane of covering 1200 can be anisotropic so that it is highly oriented in one direction.

[0141] Membrane material composites can be incorporated that result in relatively unfolded articles (e.g., tubular morphology) at both the initial smaller diameter and the expanded larger diameter. Such materials can be configured to exhibit a high degree of elongation (longitudinal and / or radial). Such high elongation capabilities can be promoted by processing relatively straight fibrils into serpentine fibrils (or otherwise bent or compressed fibrils), which become substantially straight upon application of a force in a direction opposite to the direction of compression. Creation of serpentine fibrils can be achieved by thermally induced controlled shrinkage of expanded polytetrafluoroethylene (ePTFE) membranes by wetting the membrane with a solvent such as, but not limited to, isopropyl alcohol or Fluorinert® (a perfluorinated solvent, commercially available from 3M, Inc., St. Paul, Minnesota), or by a combination of such techniques. Shrinkage of the article does not result in visible pleats, folds, or wrinkles of the ePTFE, unlike that which occurs during mechanical compression. Such shrinking can be applied to very thin membranes, which can then be combined with one or more other materials (e.g., elastomers and / or lubricious materials) to form a composite membrane that is smooth (e.g., has few or no wrinkles, folds, pleats, etc. over a major portion, substantially all, or entirety of its surface) and has a high degree of extensibility from an initial, smaller diameter, which is also smooth at the expanded, larger diameter. Additional examples of shrinkable membranes and related forming techniques can be found in U.S. Patent Application Publication No. 2018 / 0177583, filed February 22, 2018, to Cully et al.

[0142] Suitable reinforcing materials include, but are not limited to, aromatic and aliphatic polyurethanes, including copolymers, styrene block copolymers, silicones, thermoplastic elastomers, fluorosilicones, fluoroelastomers, THVs, and latexes. In some examples, the reinforcing material includes an aromatic polyester-based thermoplastic polyurethane (TPU), such as Tecothane™.

[0143] In various examples, the membrane of the covering 1200 can be reinforced with a reinforcing material by absorption or other known processes to form the covering 1200 with elastomeric properties. In various examples, the covering 1200 can be blood impermeable, such that the introducer sheath 1000 is blood impermeable (even if the support framework is otherwise permeable to blood). Such a configuration can minimize leakage of blood from the introducer sheath 1000. In some examples, the covering 1200 forms a lubricious and / or impermeable portion (e.g., one or more layers) of the sheath 1000.

[0144] The reinforcing material may be applied to the membrane of the covering 1200 via any number of conventional methods, including, but not limited to, lamination, transfer roll coating, wire wound bar coating, reverse roll coating, solution coating, or other known processes that operate to at least partially fill (e.g., absorb) some of the pores of the membrane material with the reinforcing material. For example, in some instances, the reinforcing material is solution absorbed into the membrane material of the covering 1200. In some such instances, a continuous polymer layer is dissolved in a suitable solvent and coated onto and throughout the membrane material using a wire wound rod process. The coated membrane material is then passed through a solvent oven and the solvent is removed, leaving a continuous polymer layer of the reinforcing material coated onto and throughout the membrane material. Thus, in some instances, the reinforcing material may be absorbed into the membrane material such that the absorbed reinforcing material fills the pores of the membrane material.

[0145] In some instances, such as when silicone is used as the reinforcing material, the coated membrane material may not require removal of the solvent. In another embodiment, the reinforcing material is coated onto at least one side of the membrane material and then cured. For example, an ultraviolet (UV) curable urethane can be applied to the membrane material and subsequently exposed to UV light and cured to form the covering 1200.

[0146] The reinforcing material can be coated on one or both sides of the membrane material to form the covering 1200. The membrane and / or reinforcing material can be configured such that the covering 1200 forms a lubricious layer on the introducer sheath 1000. Such a lubricious layer operates to reduce friction between the introducer sheath 1000 and one or more medical devices and the vasculature.

[0147] In various examples, the covering 1200 can be coupled to the support framework (e.g., 1100 and / or 1300) over the entire length of the support framework (e.g., 1100 and / or 1300) or over only a portion of the length of the support framework. The covering 1200 can be intermittently joined (e.g., at the proximal and distal ends of the support framework, at one or more nodes 1110 of the strut elements 1108, and / or along one or more strut elements 1108). Alternatively, the covering 1200 can be joined to substantially all of the outward and / or inward portions of the strut elements 1108. Thus, it should be understood that the covering 1200 can be disposed on the outside of the framework (e.g., 1100 and / or 1300), the inside of the framework (e.g., 1100 and / or 1300), or both. In some instances where the covering 1200 extends along both the inside and outside of the framework (e.g., 1100 and / or 1300), the covering 1200 may include a continuous tube that is everted on itself to form the inner portion 1202 and the outer portion 1204 with the framework (e.g., 1100 and / or 1300) located therebetween (see, e.g., FIG. 3A). In some instances, the inner portion and the outer portion 1202 and 1204 may be bonded together according to a manufacturing process disclosed herein. In some such instances, the covering 1200 may be everted (and thus include a transition between the inner portion and the outer portion) at either the proximal end 1002 or the distal end 1004 of the introducer sheath 1000 such that the distance between the proximal end 1002 and the distal end 1004 defines the axial length of the introducer sheath 1000. In some examples where covering 1200 is inverted and extends along both the outside and inside of a framework (e.g., 1100 and / or 1300), the free ends of covering 1200 (e.g., ends opposite a transition) can be joined to one another such that covering 1200 is substantially continuous (e.g., does not include gaps that would otherwise expose the supporting framework).In some examples, covering 1200 may additionally or alternatively comprise or be formed from one or more wraps or windings of material forming covering 1200 as described herein around one or more portions of the support framework (e.g., 1100 and / or 1300).

[0148] In some instances, attachment of the covering 1200 to the framework (e.g., 1100 and / or 1300) can be accomplished by mechanical means such as fibers, adhesives, or separate mechanical attachment points (e.g., clips). These components can also be bonded together by heat treatment (e.g., sintering a material) or by using a wrap (e.g., tube, tape, membrane, etc.) around the outside of the framework (e.g., 1100 and / or 1300) and the covering 1200 (continuous or discontinuous) attached via either a thermoplastic or thermosetting adhesive. A combination of these methods can also be used.

[0149] Suitable biocompatible adhesives include thermoplastic adhesives such as fluorinated ethylene propylene (FEP), polyurethanes, cyanoacrylates, thermoplastic fluoropolymers including fluoroelastomers, etc. Thermosetting adhesives such as urethanes or silicones including room temperature vulcanizing (RTV) silicones are also useful.

[0150] 1 and 6, the introducer sheath 1000 is operable to expand and contract to facilitate delivery of one or more medical devices through a lumen 1006 of the introducer sheath 1000. FIG. 6 provides an illustration of the introducer sheath 1000 having a medical device 1400 extending from the lumen 1006 of the introducer sheath 1000 at a proximal end 1002 of the introducer sheath 1000. As shown, the proximal end 1002 of the introducer sheath 1000 is expanded (e.g., diameter d2) relative to a distal end 1004 of the introducer sheath 1000 (e.g., post-delivery diameter d1). Similarly, the proximal end 1002 of the introducer sheath 1000 is expanded relative to an intermediate portion 1008 of the introducer sheath 1000 between the proximal end 1002 and the distal end 1004. This expansion of the proximal end 1002 of the introducer sheath 1000 is in response to the profile of the medical device 1400 expanding beyond its initial diameter (eg, FIG. 2d0).

[0151] 6, it should be understood that the medical device 1400 is in the process of being withdrawn proximally from the lumen 1006 of the introducer sheath 1000 in the direction of arrow 1401 after having been advanced distally through the lumen 1006 of the introducer sheath 1000 and out of the distal end 1004 of the introducer sheath 1000. It should also be understood that, therefore, the intermediate portion 1008 and the distal end 1004 of the introducer sheath 1000 have each contracted from an expanded diameter d2 to a post-delivery diameter shown as d1. That is, the intermediate portion 1008 and the distal end 1004 were pre-expanded in diameter to accommodate the profile of the medical device 1400, but the intermediate portion 1008 and the distal end 1004, respectively, contracted to a diameter d1 after delivery as a result of the distal end 1403 of the medical device 1400 being proximal to the intermediate portion 1008 and the distal end 1004, respectively.

[0152] As shown in FIG. 6, the closed cells in the expanded region of the introducer sheath 1000 (e.g., closed cell 1112a in row 1114a shown in dashed lines) are expanded relative to the closed cells in the non-expanded region of the introducer sheath 1000 (e.g., closed cell 1112b in row 1114b shown in dashed lines).

[0153] As noted above, in various embodiments, the introducer sheath 1000 is configured to allow the introducer sheath 1000 to self-recover from a larger expanded diameter to a diameter smaller than the larger expanded diameter, without requiring an external force for such recovery. Thus, this expansion and contraction of the introducer sheath 1000 can be gradual along the length of the introducer sheath 1000. Thus, it should be understood that the entire length of the introducer sheath 1000 is not configured to have to be in either the expanded configuration or the contracted / initial configuration. Instead, it should be understood that the introducer sheath 1000 is configured such that one or more portions (e.g., regions, lengths, or sections) are expandable relative to one or more other portions of the introducer sheath 1000. Thus, a first portion of the introducer sheath 1000 can be in an initial configuration (e.g., d0, see FIG. 1 ), while a second portion of the introducer sheath 1000 is in an expanded configuration (e.g., diameter d2), and / or while a third portion of the introducer sheath 1000 is in a restored configuration (e.g., diameter d1). Similarly, a portion of the introducer sheath 1000 can be in an expanded configuration (e.g., diameter d2), while another portion of the introducer sheath 1000 is in a restored configuration (e.g., diameter d1). It should be understood that one or more portions (e.g., regions, lengths, or sections) of the introducer sheath 1000 can be any length and thus are not limited to a discreet length or a discreet section.

[0154] In various examples, the expanded diameter (e.g., d2) is generally any diameter of the lumen 1006 that is greater than the initial diameter of the lumen 1006 that results in response to an outward force applied to a given portion of the introducer sheath 1000. In various examples, when a medical device having a profile (e.g., diameter) that exceeds the initial diameter of the lumen 1006 advances through the lumen 1006 of the introducer sheath 1000, such medical device contacts the introducer sheath 1000 (e.g., along the luminal wall of the lumen) and thereby applies an outward force to the introducer sheath 1000, causing the lumen 1006 of the introducer sheath 1000 to expand the area of ​​contact to accommodate the profile of the medical device.

[0155] In some instances, the introducer sheath 1000 is operable to expand the lumen diameter up to 300 percent of the initial diameter while maintaining the ability of the introducer sheath 1000 to self-restore the lumen diameter to the post-delivery diameter. In some instances, the introducer sheath 1000 is operable to expand the lumen diameter 25-100 percent, 100-125, 125-200, or 200-300 percent of the initial diameter while maintaining the ability of the introducer sheath 1000 to self-restore the lumen diameter to the post-delivery diameter.

[0156] In various examples, the post-delivery diameter (e.g., d1) generally refers to the diameter of the lumen 1006 after the introducer sheath 1000 has self-recovered the diameter of the lumen (e.g., in a restored configuration) in response to removal of an outward force. That is, in various examples, the introducer sheath is configured to automatically recover to the post-delivery diameter without the influence of an external force. As discussed herein, such ability is based on an internal bias of the introducer sheath 1000 that is the result of the interaction between the support framework (e.g., 1100 and / or 1300) and the covering 1200. Thus, the post-delivery diameter will be smaller than the expanded diameter.

[0157] In some instances, the post-delivery diameter and the initial diameter are the same diameter. In some instances, the post-delivery diameter is no more than 10 percent greater than the initial diameter (e.g., no more than 1, 2, 3, 4, 5, 6, 7, 8, or 9 percent greater than the initial diameter) and is less than the expanded diameter. In some instances, the post-delivery diameter is in the range of 10-15 percent of the initial diameter. In some instances, the introducer sheath 1000 is configured to have a resting diameter (e.g., the initial diameter or the post-delivery diameter) that is less than the diameter of the anatomical structure in which the introducer sheath 1000 is disposed. For example, the combined internal forces of the support framework (e.g., 1100 and / or 1300) and covering 1200 are configured to maintain the introducer sheath 1000 at a diameter smaller than the diameter of the surrounding anatomical structure when no external forces (i.e., forces other than the internal forces of the support framework of the covering) (e.g., forces applied by a device disposed within the lumen 1006 of the introducer sheath 1000) are applied to the introducer sheath 1000. Thus, the introducer sheath 1000 is configured to reduce or minimize contact with the surrounding tissue when not subject to an external force.

[0158] In some instances, the introducer sheath 1000 includes one or more lubricious liner layers to provide a lubricious interface that reduces friction between a medical device or instrument to be delivered and the introducer sheath 1000 to facilitate delivery of the medical device or instrument through the introducer sheath 1000. For example, a lubricious liner layer can be disposed on, define, or otherwise included in an interior surface, such as the interior portion 1202 of the introducer sheath 1000, such that the lubricity provided by the lubricious liner layer reduces friction between the medical device and the interior portion 1202 during delivery. The lubricious liner layer has a lubricious interior surface (e.g., a majority of, substantially all, or the entire surface) when the lumen 1006 of the introducer sheath 1000 is at an initial diameter and when the lumen 1006 is expanded to an expanded diameter. In some examples, a lubricious liner layer can be disposed about, defining, or otherwise included in an outer surface, such as the outer portion 1204 of the introducer sheath 1000, so that, for example, the introducer sheath 1000 can be advanced through another lumen, such as within a separate catheter that is coupled to the introducer sheath 1000 during a procedure. In some examples, the introducer sheath 1000 has a smooth continuous inner surface and a smooth continuous outer surface (e.g., a majority of, substantially all, or the entire surface) both when the sheath 1000 is at its initial diameter and when the sheath 1000 is expanded to its expanded diameter.

[0159] In some instances, the elasticity of the sheath 1000 maintains a smooth surface. This can be contrasted with less elastic or non-elastic designs that, for example, fold, wrinkle, crease, pleat, or otherwise become non-smooth when collapsed from the expanded diameter to the initial diameter. Various embodiments are particularly advantageous in that they incorporate a hydrogel coating or any other suitable lubricant or lubricous surface treatment, while also incorporating the elasticity necessary to transition between the initial diameter and the expanded diameter to remain smooth. Various examples of lubricious liner layer materials and configurations are described further herein.

[0160] The ability of the introducer sheath 1000 to self-heal provides that such regions of the introducer sheath 1000 that are not expanded as a result of the presence of a medical device in those regions are operable to maintain a minimal profile within the vasculature, reducing occlusion of the blood vessel and reducing trauma to the blood vessel.

[0161] As noted above, the self-healing ability of the introducer sheath 1000 is based on a bias present in one or more of the support frameworks (e.g., 1100 and / or 1300) and the covering 1200. In various examples, such bias is in the form of potential energy stored in one or more of the support frameworks (e.g., 1100 and / or 1300) and the covering 1200, which is converted to kinetic energy to enable the introducer sheath 1000 to self-heal the diameter of the lumen 1006. In some examples, one or more of the support frameworks (1100 and / or 1300) and the covering 1200 are elastically deformable. Thus, in various examples, the introducer sheath 1000 is elastically deformable, at least in part, due to the elasticity of one or more of the support frameworks (e.g., 1100 and / or 1300) and the covering 1200 when elastically deformed.

[0162] In some examples, the covering 1200 is configured to stretch with the expanded introducer sheath 1000, where the covering 1200 stores potential energy when it is stretched (e.g., the covering 1200 is elastically deformed). In some examples, the covering 1200 is stretched or elastically deformed when the lumen 1006 of the introducer sheath 1000 is at an initial diameter. Thus, in some such examples, the covering 1200 is configured to store potential energy when the introducer sheath 1000 is in an initial configuration in which the lumen 1006 is at the initial diameter. In various examples, the potential energy of the covering 1200 can be converted to kinetic energy to help self-restore the diameter of the lumen 1006 to a post-delivery diameter after the introducer sheath 1000 is expanded to a diameter greater than each of the initial and post-delivery diameters. In some instances, the potential energy is stored in the membrane material of the covering 1200. In some instances, the potential energy is additionally or alternatively stored in a reinforcement material of the covering 1200.

[0163] Additionally or alternatively, in some examples, the support framework (e.g., 1100 and / or 1300) is configured to store potential energy in one or more of the above configurations of the introducer sheath 1000. For example, in some examples, the support framework (1100 and / or 1300) stores potential energy when the lumen 1006 of the introducer sheath 1000 is expanded to a diameter greater than each of the initial diameter and the post-delivery diameter. In some such examples, the support framework may be shaped to a profile that the support framework adopts when the lumen 1006 of the introducer sheath 1000 is at an initial diameter (e.g., d0). That is, in some examples, the support framework may be shaped to a profile that the support framework adopts when the introducer sheath 1000 is in an initial configuration. Thus, the support framework (1100 and / or 1300) may include a shape memory material that is shape-set to a configuration different from the configuration adopted by the support framework when the introducer sheath 1000 is expanded.

[0164] However, in other examples, the support framework (1100 and / or 1300) may be shaped to a configuration different than the configuration adopted by the support framework when the introducer sheath 1000 is in an initial configuration in which the lumen 1006 is at an initial diameter. In some such examples, the support framework (1100 and / or 1300) stores potential energy when the lumen 1006 of the introducer sheath 1000 is at one or more of the initial diameter and the post-delivery diameter. In some examples, the support framework may be shaped to a profile that the support framework adopts when the introducer sheath 1000 is in a configuration between the initial configuration and the expanded configuration (e.g., an intermediate configuration in which the lumen diameter exceeds the initial diameter and the lumen diameter is less than the expanded diameter). In various examples, the potential energy of the support framework can be converted into kinetic energy, helping the diameter of the lumen 1006 to self-restore to a post-delivery diameter after the introducer sheath 1000 is expanded to a diameter larger than each of the initial diameter and the post-delivery diameter.

[0165] In examples where the support framework (e.g., 1100 and / or 1300) is shaped to an intermediate configuration, it should be understood that the support framework stores potential energy when the lumen of the introducer sheath 1000 has an initial diameter and when the introducer sheath 1000 is in an expanded configuration. Thus, it should be understood that in some examples, the introducer sheath 1000 may be configured such that the support framework (e.g., 1100 and / or 1300) and the covering 1200 each store potential energy when the introducer sheath 1000 is in the initial configuration. For example, the support framework (e.g., 1100 and / or 1300) may be shaped to the intermediate configuration described above, and the covering 1200 may be applied to the support framework such that the covering 1200 biases the introducer sheath 1000 toward a contracted configuration in which the lumen diameter is smaller than the initial diameter. Under such conditions, when the lumen 1006 of the introducer sheath 1000 has an initial diameter, the support framework (eg, 1100 and / or 1300) and covering 1200 are elastically tensioned.

[0166] Thus, the elastically radially contracted support framework (1100 and / or 1300) biases the introducer sheath 1000 radially outward (e.g., with a radially outward vector), and the covering 1200 thus biases the introducer sheath 1000 radially inward (e.g., with a radially inward vector). In some such instances, the radially outward bias of the support framework (1100 or 1300) and the radially inward bias of the covering 1200 are in equilibrium when the lumen 1006 of the introducer sheath 1000 has an initial diameter. In other words, in some examples, the introducer sheath 1000 can be configured such that a first force associated with the potential energy of the covering 1200 and a second force associated with the potential energy of the support framework (e.g., 1100 and / or 1300) are in equilibrium with one another when the lumen 1006 of the introducer sheath 1000 has an initial diameter. It should be appreciated that in various examples, such an equilibrium between the first and second forces also occurs when the lumen 1006 of the introducer sheath 1000 has a post-delivery diameter.

[0167] The various configurations of the introducer sheath 1000 described herein are such that the introducer sheath is configured to expand uniformly in a radial direction, such as relative to a longitudinal axis of the introducer sheath 1000. For example, unlike some conventional systems, the introducer sheath 1000 of the present disclosure does not include flaps or folds or reliefs that operate to facilitate the expansion of the introducer sheath 1000. Instead, as described herein, the introducer sheath 1000 of the present disclosure includes a framework (e.g., 1100 and / or 1300) and coverings that are arranged such that the covering 1200 stretches to accommodate the expansion of the introducer sheath 1000. The configuration of the support framework is also such that the support framework expands uniformly in a radial direction. In other words, the introducer sheath 1000 does not include folds, flaps, reliefs, or other features that facilitate an increase in the diameter of the lumen of the introducer sheath 1000.

[0168] In various examples, in addition to expanding radially uniformly, the introducer sheath 1000 is configured to maintain a smooth outer surface (e.g., a majority of, substantially all, or the entire surface) when the lumen is at the initial diameter, the expanded diameter (or expanded diameter), and the post-delivery diameter. For example, the outer surface of the introducer sheath 1000 can remain smooth and wrinkle-free when radially expanded at about 50% or more of the initial diameter, and the introducer sheath 1000 can radially expand and contract after the introducer sheath 1000 is deployed in a vessel within the body without folding or otherwise deflecting inwardly within the lumen of the introducer sheath 1000. In some examples, the covering 1200 is applied to the support framework (e.g., 1100 and / or 1300) such that the covering 1200 is tensioned (e.g., stores potential energy) around the support framework at each of the introduction diameter, the expanded diameter, and the post-delivery diameter, as described above. At a minimum, covering 1200 is applied to the support framework such that covering 1200 is wrinkle-free at each of the introduction diameter, the expanded diameter, and the post-delivery diameter, as described above.

[0169] In various examples, introducer sheath 1000 can be formed by providing a frame including a plurality of strut elements arranged to form a tubular framework, and coupling covering 1200 to the frame such that the frame and covering 1200 define a sheath having a lumen extending therethrough. The frame corresponds to any of the support frameworks (e.g., 1100 and / or 1300) described herein. Covering 1200 corresponds to any of the coverings 1200 described herein.

[0170] In some examples, the method includes shaping the frame to an initial configuration having an initial diameter. In some examples, the frame is shaped to an initial configuration in which the lumen of the sheath is at an initial diameter (e.g., d0) referred to herein. In some other examples, the frame is shaped to a configuration in which the lumen of the sheath is at a diameter greater than the initial diameter. In other such examples, the covering 1200 can be coupled to the frame such that the frame is radially compressed to a contracted configuration such that potential energy is stored in the frame when the lumen of the sheath is at an initial diameter (e.g., d0) referred to herein. Additionally or alternatively, coupling the covering 1200 to the frame can include coupling the covering 1200 to the frame such that the covering 1200 stores potential energy when the lumen of the sheath has an initial diameter (e.g., d0) referred to herein. In some such examples, the covering 1200 can be stretched when it is coupled to the frame.

[0171] In various examples, the frame may be shaped to an initial configuration before or after the covering 1200 is coupled to the frame. In some examples, coupling the covering 1200 to the frame to define the sheath includes the use of a forming mandrel. In some such examples, the covering 1200 is placed around the mandrel and then the frame is placed around the covering 1200. In some examples, the covering 1200 may be placed around the covering 1200 on the mandrel such that the first portion of the covering 1200 is positioned between the first end and the second end of the frame and the second portion of the covering 1200 extends beyond one of the first end and the second end of the frame. In such examples, the second portion of the covering 1200 may be trimmed. Alternatively, the second portion may be inverted onto the frame such that the frame is positioned between the first and second portions of the covering 1200.

[0172] 7-19 illustrate a process of using the introducer sheath 1000 to deploy one or more medical devices 2100, including, but not limited to, valve prostheses such as transcatheter mitral valve replacement (TMVR) prostheses and transcatheter aortic valve replacement (TAVR) prostheses, as well as other types of suitable medical devices.

[0173] 7, the medical device 2100 is attached to the delivery catheter 1500 proximate the distal end portion 1502 of the delivery catheter 1500. The delivery catheter 1500 as described herein may be formed using polymers such as silicone rubber, nylon, polyurethane, polyethylene terephthalate (PET), latex, and thermoplastic elastomers, among others. In some examples, the delivery catheter may also include laser cut hypotubes formed using materials including metals such as, but not limited to, medical grade stainless steel, for example, AISI 300 series stainless steel alloys, titanium, tantalum, alloys such as Elgiloy® and Phynox® spring alloys, MP35N® alloy, and Nitinol nickel-titanium alloy, whereby the mechanical properties of the catheter are improved, for example, to achieve increased flexibility and / or better torque characteristics. Examples of suitable delivery catheters 1500 and associated implantable medical devices can be found in U.S. Patent Application Publication No. 2019 / 0125534, entitled "Transcatheter Deployment Systems and Associated Methods," filed September 12, 2018.

[0174] In the illustration of Figure 7, the medical device 2100 (e.g., a prosthetic heart valve) is shown in an expanded or delivery configuration. An in-line sheath dilator 1504 is disposed on the exterior of the delivery catheter 1500 such that the delivery catheter 1500 passes through the lumen of the in-line sheath dilator 1504. The in-line sheath dilator 1504 has a proximal opening 1514, a distal opening 1516, and a dilator lumen 1518 extending therethrough. In some instances, the dilator lumen 1518 slidably receives the delivery catheter 1500, and the distal opening 1516 has a larger diameter than the proximal opening 1514.

[0175] 8 shows the medical device 2100 in a compacted or delivery configuration. In some instances, the medical device 2100 has an initial or compacted diameter, for example, in the range of 6 Fr to 16 Fr. The diameter of the medical device 2100 in the compacted configuration can be equal to or less than about the diameter of the lumen of the in-line sheath expander 1504.

[0176] 9 shows an in-line sheath dilator 1504 being advanced over the compacted medical device 2100 toward the distal end portion 1502 to cover the medical device 2100, according to some delivery methods. As shown, the in-line sheath dilator 1504 is configured to engage the distal end portion 1502 (e.g., the distal end portion 1502 optionally has a diameter equal to or greater than about the inner diameter of the in-line sheath dilator 1504).

[0177] Figure 10 illustrates an introducer sheath 1000 in an initial, unexpanded state. As shown in Figure 10, an elastic dilator 1508 is inserted through a lumen of the sheath 1000 (e.g., to facilitate introduction of the sheath 1000 into a patient's body). As shown, a guidewire 1506 is received through the sheath 1000. As shown, the dilator 1508 can be retracted to leave the sheath 1000 receiving the guidewire 1506.

[0178] Thereafter, as shown in Figure 12, a delivery catheter 1500 with an in-line sheath expander 1504, as shown in Figure 9, is advanced over the guidewire 1506 towards the introducer sheath 1000. For example, the delivery catheter 1500 is optionally passed through an auxiliary component 2000 (e.g., a hemostasis valve hub).

[0179] 13, the delivery catheter 1500 and the in-line sheath expander 1504 are inserted through the introducer sheath 1000 until the proximal engagement portion 1510 of the in-line sheath expander 1504 contacts a proximal portion of the introducer sheath 1000 (e.g., auxiliary component 2000). At this stage, the distal end portion 1502 of the delivery catheter 1500 protrudes from the introducer sheath 1000 and the in-line sheath expander 1504. In some instances, the proximal engagement portion 1510 is coupled (e.g., releasably engaged) to the proximal portion of the introducer sheath 1000. When the in-line sheath dilator 1504 is extended through the introducer sheath 1000, the in-line sheath dilator expands the sheath 1000 to an expanded diameter that is larger than the initial diameter when the introducer sheath 1000 conforms to the shape and size of the in-line sheath dilator 1504. For visualization purposes, the position of the in-line sheath dilator 1504 is shown with a dotted line in Figures 13, 14, 16 and 17.

[0180] As shown in Figure 14, after the distal end of the delivery catheter 1500 is positioned near a desired delivery site within a patient's body, the delivery catheter 1500 can be decoupled from the in-line sheath expander 1504 or otherwise extended from the distal end portion 1502 of the in-line sheath expander 1504 such that the delivery catheter 1500 can be advanced forward with the medical device 2100 in the compacted configuration. As shown in Figure 14, the in-line sheath expander 1504 is secured to maintain the introducer sheath 1000 in an expanded state.

[0181] 15 illustrates one example of how a medical device 2100 may be delivered to a desired location through the body's vasculature. As shown, an introducer sheath 1000 is introduced through a percutaneous access site 1512, which may be a surgically opened opening for inserting a delivery catheter 1500. A guidewire 1506 guides the distal end portion 1502 of the delivery catheter 1500, thus helping to guide the medical device 2100 to a desired location within the vasculature 1515 where the medical device 2100 may be deployed or other operations may be performed.

[0182] Figure 16 shows the delivery catheter 1500 after deployment of the medical device 2100 within the vasculature 1515. In some instances, following device delivery, the delivery catheter 1500 is retracted such that the distal end portion 1502 reconnects with the in-line sheath expander 1504, as shown in Figure 17. For example, such connection can provide a smooth outer profile (e.g., a majority, substantially all, or the entire surface) for removal of the delivery catheter 1500 and in-line sheath expander 1504 from the body.

[0183] 18 shows the delivery catheter 1500 coupled with the in-line sheath dilator 1504 and further retracted along the guidewire 1506 so that they are withdrawn in unison from the introducer sheath 1000. After the delivery catheter 1500 and the in-line sheath dilator 1504 are retracted, the introducer sheath 1000 is withdrawn from the vasculature 1515, as shown in FIG.

[0184] In the above examples, to facilitate easy insertion of the in-line sheath dilator 1504 through the introducer sheath 1000, a lubricious interface (e.g., one or more lubricious layers) can be disposed between the in-line sheath dilator 1504 and the introducer sheath 1000 to reduce friction therebetween. In some examples, the lubricious interface is relatively non-distancing or relatively inelastic.

[0185] 20A, 20B, 21A and 21B, the lubricious interface includes a tubular member defining a non-elastic lubricious liner 1602 coupled to another tubular member, an introducer sheath 1000. The introducer sheath 1000 can be either non-elastic (e.g., FIGS. 20A and 20B) or elastic (e.g., FIGS. 21A and 21B).

[0186] 20A illustrates an example where the introducer sheath 1000 includes a non-elastic sheath 1600 with a non-elastic lubricious liner 1602. As shown, the non-elastic sheath 1600 is coupled with the non-elastic lubricious liner 1602 such that both the non-elastic sheath 1600 and the non-elastic lubricious liner 1602 have a pleated configuration when collapsed to have an initial diameter. The pleats 1604 are formed by folding back a portion of both the non-elastic sheath 1600 and the non-elastic lubricious liner 1602 to overlap another portion within the non-elastic sheath 1600 and the non-elastic lubricious liner 1602. The amount of overlap can be adjusted to achieve various diameters and expansion capabilities. In particular, when the inelastic sheath 1600 and the inelastic lubricious liner 1602 are expanded to an expanded diameter greater than the initial diameter, the pleats 1604 are released and the inelastic sheath 1600 and the inelastic lubricious liner 1602 become unpleated, as shown in Figure 20B. Although a single pleat is shown, any number of pleats may be incorporated as desired (e.g., 2, 3, 4, 6, 12, etc.).

[0187] 21A illustrates an example where the introducer sheath 1000 includes an elastic sheath 1606 configured to be elastically expanded and a non-elastic lubricious liner 1602. As shown, pleats 1608 are formed in the non-elastic lubricious liner 1602, where one portion of the non-elastic lubricious liner 1602 is folded over another portion in an overlapping configuration. Although a single pleat is shown, any number of pleats can be incorporated as desired (e.g., two, three, four, six, twelve, etc.). The elastic sheath 1606 remains in an unpleated configuration (e.g., relatively wrinkle-free) regardless of whether the elastic sheath 1606 is at an initial diameter or an expanded diameter. On the other hand, as shown in FIG. 21B, when the non-elastomeric lubricious liner 1602 is expanded to an expanded diameter (e.g., corresponding to the state when the in-line sheath expander 1504 and / or delivery catheter 1500 is passed through the sheath), the pleats 1608 of the non-elastomeric lubricious liner 1602 are released and the non-elastomeric lubricious liner 1602 becomes unpleated.

[0188] In yet another embodiment, the in-line sheath expander 1504 has a lubricious interface. In some examples, the outer surface of the in-line sheath expander 1504 comprises a lubricious material, including but not limited to PTFE, high density polyethylene (HDPE), polyimide, or a thermoplastic with a hydrophilic coating. In some examples, the inner surface of the elastic sheath 1606 comprises a radially expandable elastomer, including but not limited to silicone, polyurethane, thermoplastic elastomer (TPE), or thermoplastic vulcanizate (TPV).

[0189] As one example, Figure 22A shows a sheath 1000 that includes an elastic sheath 1606 without an associated lubricious liner. In some examples, a lubricious layer, such as a non-elastic lubricious liner 1602, is coupled to the outer surface of the in-line sheath expander 1504. In some examples, the lubricious layer is a hydrogel coating applied onto the outer surface of the in-line sheath expander 1504 such that the elastic sheath 1606 can slide more easily along the outer surface of the in-line sheath expander 1504 when the in-line sheath expander 1504 is inserted into the elastic sheath 1606 to expand the elastic sheath 1606 to achieve an expanded diameter.

[0190] Although lubricious coatings or other types of liners and interfaces are contemplated, in some instances, the elastic sheath 1606 has an inner surface that is lubricious so as to not require additional or supplemental lubricious liners within the elastic sheath 1606. For example, the elastic sheath can include an inner surface formed from a polymer, including but not limited to, PTFE or ePTFE, that has been imbibed with a lubricious hydrogel. In one example, the lubricious hydrogel is an organic compound, including but not limited to, polyols, polyvinylpyrrolidone (PVP), isocyanates, or any other suitable lubricant. Incorporating a lubricious inner surface or liner layer can help reduce friction between the outer surface of the in-line sheath expander 1504 and the inner surface of the elastic sheath 1606. In some instances, the lubricious liner layer provides a lubricious inner surface when the lumen of the elastic sheath 1606 is at its initial smaller diameter and also provides a lubricious inner surface when the lumen of the elastic sheath 1606 is at its expanded larger diameter. Various materials can be implemented to achieve a smooth configuration (e.g., a majority, substantially all, or the entire surface) at both the initial smaller diameter and the expanded larger diameter, such as the shrink membranes and shrink membrane composites described above.

[0191] The incorporation of an expandable lubricious liner provides the ability to provide a continuous, smooth surface (e.g., a majority, substantially all, or the entire surface) to allow expansion from an initial diameter to a larger diameter without having to split, unfold, form releasable pleats, or otherwise incorporate features to accommodate a relatively non-extensible material in the liner.

[0192] In some instances, when the inner surface of the elastic sheath 1606 is lubricious, the outer surface of the elastic sheath 1606 is not lubricious. In some instances, the elastic sheath 1606 is formed by fusing or adhering together two or more layers of different polymeric membranes, where one or more outer membrane layers define the properties of the outer surface of the elastic sheath 1606 and one or more inner layers define the properties of the inner surface of the elastic sheath 1606. In some instances, the outer layer is a polymer that has not been imbibed with a lubricious hydrogel material (e.g., is relatively free of lubricious components), while the inner layer is a polymer that has been imbibed with a lubricious hydrogel material (or other lubricious components), such that the elastic sheath 1606 has a lubricious inner surface and a non-lubricious outer surface. EXAMPLES

[0193] example The expandable introducer sheath was fabricated according to the following method: An unabsorbed polymeric tape was wrapped around a cylindrical mandrel with 20 cigarette turns (e.g., wrapped longitudinally with the transverse direction of the tape perpendicular to the length of the mandrel). The mandrel and tape were then heated for about 10 minutes. After cooling, 15 layers of the polymeric tape imbibed with a reinforcing material were wrapped with cigarette turns over the existing 20 layers of unabsorbed polymeric tape with the reinforcing material facing the mandrel. The mandrel and tape were then heated for about 5 minutes. A support framework consistent with the disclosure herein was then placed around the wrapped polymeric tape. The excess length of the polymeric tape extending beyond the end of the support framework was then turned over to the outside of the support framework. Another polymeric tape was then wrapped around a portion of the structure to maintain the relative positions of the tape and the support framework. The structure was then heated for 5 minutes. After cooling, the structure was removed from the mandrel.

[0194] Numerous features and advantages, including various alternatives as well as details of the structure and function of the device and / or method, have been described in the above description. The present disclosure is for illustrative purposes only and is not intended to be exhaustive as such. It will be apparent to those skilled in the art that various modifications may be made, particularly with respect to the structure, materials, elements, components, shapes, sizes and arrangements of parts, including combinations within the principles of the disclosure, within the full scope indicated, according to the broad and general meaning of the terms in which the appended claims are expressed. It is intended that these various modifications are included therein unless they depart from the spirit and scope of the appended claims. (Aspect) (Aspect 1) a frame including a plurality of strut elements arranged to form a tubular framework; and a covering extending along a portion of the frame, the frame and the covering extending such that they define a sheath having a lumen extending therethrough; Including, A medical device, wherein the strut elements of the frame interact with each other to provide the sheath with axial compression resistance and hoop strength, the lumen has a length, the sheath is radially expandable such that a diameter of the lumen expands from an initial diameter to an expanded diameter larger than the initial diameter to accommodate passage of one or more devices therethrough, and the sheath is further configured to self-restore the diameter of the lumen to a post-delivery diameter smaller than the expanded diameter along the length of the sheath in response to the one or more devices being removed from the lumen. (Aspect 2) The medical device of embodiment 1, wherein the covering is configured to stretch so that the sheath is radially expandable, the covering stores potential energy when the lumen of the sheath is expanded to the expanded diameter, and the potential energy of the covering can be converted to kinetic energy, thereby causing the sheath to self-restore the diameter of the lumen to a post-delivery diameter. (Aspect 3) The medical device of any one of the preceding aspects, wherein the frame is configured to store potential energy when the sheath is expanded to an expanded diameter, and the potential energy of the frame is convertible to kinetic energy, thereby causing the sheath to self-restore the diameter of the lumen to a post-delivery diameter. (Aspect 4) The medical device of any one of aspects 1 to 3, wherein the frame is shaped into an initial configuration in which a diameter of the lumen of the sheath is greater than an initial diameter, such that when the lumen of the sheath has the initial diameter, the frame stores potential energy. (Aspect 5) 2. The medical device of any one of the preceding embodiments, wherein the post-delivery diameter is no more than 115% of the initial diameter. (Aspect 6) 20. The medical device of any one of the previous aspects, wherein the sheath is configured to have a smooth outer surface when the sheath self-recovers the diameter of the lumen to a post-delivery diameter. (Aspect 7) 2. The medical device of any one of the preceding aspects, wherein the covering forms a lubricious, impermeable layer of the sheath. (Aspect 8) The medical device of any one of the previous aspects, wherein a plurality of distinct zones are defined along an axial length of the sheath, and the sheath is configured to progressively expand and self-recover such that a diameter of the lumen at a first zone of the plurality of distinct zones is expandable relative to a diameter of the lumen at a second zone of the plurality of distinct zones, and a diameter of the lumen at the first zone is self-recoverable to the post-delivery diameter. (Aspect 9) The medical device of any one of the preceding aspects, wherein the diameter of the lumen is configured to be expandable to an expanded diameter at a first cross-section along the axial length of the sheath without causing an expansion of the diameter of the lumen from an initial diameter at a second cross-section along the axial length of the sheath, and the diameter of the lumen is configured to be self-recoverable to a post-delivery diameter at the first cross-section without causing a decrease in the diameter of the lumen at the second cross-section. (Aspect 10) a delivery catheter having a distal end portion; an expandable sheath having a lumen extending therethrough, the lumen having a length, and the expandable sheath being radially expandable such that a diameter of the lumen is operable to expand from an initial diameter to an expanded diameter that is greater than the initial diameter; and an in-line sheath expander configured to receive the delivery catheter and releasably couple to a distal end portion of the delivery catheter, the in-line sheath expander and the delivery catheter being slidably insertable through a lumen of the expandable sheath, the in-line sheath expander configured to expand the expandable sheath from an initial diameter to an expanded diameter; Including, A delivery system, wherein a distal end portion of the delivery catheter is extendable from the in-line sheath expander after the expandable sheath is expanded to an expanded diameter by the in-line sheath expander and the expandable sheath is maintained at the expanded diameter. (Aspect 11) The delivery system of embodiment 10, wherein the expandable sheath includes a frame including a plurality of strut elements arranged to form a tubular framework, and a covering extending along a portion of the frame, the strut elements of the frame interacting with each other to provide the expandable sheath with axial compression resistance and hoop strength. (Aspect 12) The delivery system of aspect 10 or 11, wherein the in-line sheath expander is configured to reconnect with the distal end portion of the delivery catheter after extending the distal end portion of the delivery catheter from the in-line sheath expander after expanding the expandable sheath to an expanded diameter. (Aspect 13) The delivery system of any one of aspects 10 to 12, wherein the expandable sheath is further configured to self-restore the diameter of the lumen along the length of the expandable sheath to a post-delivery diameter smaller than the expanded diameter in response to the in-line sheath expander and the delivery catheter being removed from the lumen. (Aspect 14) 14. The delivery system of any one of aspects 10 to 13, further comprising one or more devices coupled to the delivery catheter proximate a distal end portion of the delivery catheter, the one or more devices comprising a mitral valve or an aortic valve prosthesis. (Aspect 15) 15. The delivery system of any one of aspects 12-14, wherein the in-line sheath dilator includes a proximal opening, a distal opening, and a dilator lumen extending therethrough, the dilator lumen configured to slidably receive the delivery catheter, and the distal opening has a larger diameter than the proximal opening. (Aspect 16) 16. The delivery system of any one of aspects 10 to 15, wherein a plurality of distinct zones are defined along an axial length of the expandable sheath, and the expandable sheath is configured to progressively expand and self-recover such that a diameter of the lumen at a first zone of the plurality of distinct zones is expandable relative to a diameter of the lumen at a second zone of the plurality of distinct zones, and a diameter of the lumen at the first zone is self-recoverable to a post-delivery diameter relative to the second zone. (Aspect 17) The delivery system of any one of aspects 10 to 16, wherein the diameter of the lumen is configured to be expandable to an expanded diameter at a first cross-section along the axial length of the expandable sheath without causing an expansion of the diameter of the lumen from an initial diameter at a second cross-section along the axial length of the expandable sheath, and the diameter of the lumen is configured to be self-recoverable to a post-delivery diameter at the first cross-section without causing a decrease in the diameter of the lumen at the second cross-section. (Aspect 18) 1. A method for placing a transcatheter medical device within a body, comprising: advancing an in-line sheath dilator over at least a portion of the delivery catheter while the one or more devices are constrained in a distal end portion of the delivery catheter; coupling the in-line sheath dilator to a distal end portion of the delivery catheter to cover the one or more devices; advancing an expandable sheath into the body's vascular system; advancing the delivery catheter and the in-line sheath expander into the expandable sheath such that a distal end portion of the delivery catheter is adjacent to a distal end of the expandable sheath, wherein advancing the in-line sheath expander into the expandable sheath causes the expandable sheath to expand from an initial diameter to an expanded diameter that is greater than the initial diameter; and decoupling the in-line sheath dilator from a distal end portion of the delivery catheter and extending the delivery catheter from the in-line sheath dilator while maintaining the expandable sheath at an expanded diameter with the in-line sheath dilator; A method comprising: (Aspect 19) advancing the delivery catheter into the vascular system to deliver the one or more devices to a desired location; placing the one or more devices at a desired location and then withdrawing the delivery catheter from the vascular system; and decoupling the in-line sheath expander from the expandable sheath and then recoupling the in-line sheath expander to a distal end portion of the delivery catheter; 20. The method of embodiment 18, further comprising: (Aspect 20) The method of embodiment 19, further comprising retracting the in-line sheath expander and the delivery catheter from the lumen of the expandable sheath and allowing the expandable sheath to self-restore the diameter of the lumen along the length of the expandable sheath to a post-delivery diameter that is smaller than the expanded diameter.

Claims

1. a delivery catheter having a distal end portion; an expandable sheath having a lumen extending therethrough, the lumen having a length, and the expandable sheath being radially expandable such that a diameter of the lumen is operable to expand from an initial diameter to an expanded diameter that is greater than the initial diameter; and an in-line sheath expander configured to receive the delivery catheter and releasably couple to a distal end portion of the delivery catheter, the in-line sheath expander and the delivery catheter being slidably insertable through a lumen of the expandable sheath, the in-line sheath expander configured to expand the expandable sheath from the initial diameter to the expanded diameter; Including, A delivery system, wherein a distal end portion of the delivery catheter is extendable from the in-line sheath expander after the expandable sheath is expanded to the expanded diameter by the in-line sheath expander and the expandable sheath is maintained at the expanded diameter.

2. 2. The delivery system of claim 1, wherein the expandable sheath includes a frame including a plurality of strut elements arranged to form a tubular framework, and a covering extending along a portion of the frame, the strut elements of the frame interacting with each other to provide the expandable sheath with axial compression resistance and hoop strength.

3. 3. The delivery system of claim 1 or 2, wherein the in-line sheath expander is configured to reconnect with the distal end portion of the delivery catheter after extending the distal end portion of the delivery catheter from the in-line sheath expander after expanding the expandable sheath to the expanded diameter.

4. The delivery system of any one of claims 1 to 3, wherein the expandable sheath is further configured to self-restore a diameter of the lumen along a length of the expandable sheath to a post-delivery diameter smaller than the expanded diameter in response to removal of the in-line sheath expander and the delivery catheter from the lumen.

5. The delivery system of any one of claims 1 to 4, further comprising one or more devices coupled to the delivery catheter proximate a distal end portion of the delivery catheter, the one or more devices including a mitral valve or an aortic valve prosthesis.

6. 6. The delivery system of claim 3, wherein the in-line sheath dilator includes a proximal opening, a distal opening and a dilator lumen extending therethrough, the dilator lumen configured to slidably receive the delivery catheter, and the distal opening has a larger diameter than the proximal opening.

7. 7. The delivery system of claim 1, wherein a plurality of distinct zones can be defined along an axial length of the expandable sheath, the expandable sheath being configured to progressively expand and self-recover such that a diameter of the lumen at a first zone of the plurality of distinct zones is expandable relative to a diameter of the lumen at a second zone of the plurality of distinct zones, and a diameter of the lumen at the first zone is self-recoverable to a post-delivery diameter relative to the second zone.

8. 8. The delivery system of claim 1, wherein the lumen diameter is configured to be expandable to the expanded diameter at a first cross-section along the axial length of the expandable sheath without causing an expansion of the lumen diameter from the initial diameter at a second cross-section along the axial length of the expandable sheath, and the lumen diameter is configured to be self-recoverable to a post-delivery diameter at the first cross-section without causing a decrease in the lumen diameter at the second cross-section.

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