Pre-expanded expandable sheath with protective cover

Abstract

Various embodiments include an expandable sheath system (300) including a radially expandable sheath (208) including a constraining member (385) that restricts expansion of the sheath, and a method of manufacturing the same.

Description

[0001] Cross-references to related applications This application claims the benefit of U.S. Provisional Application No. 63 / 522,472, filed June 22, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This application relates to a sheath for use with catheter-based technologies for repairing and / or replacing heart valves and for delivering implants such as prosthetic valves to the heart via a patient's vascular system. Background Technology

[0003] Intravascular delivery catheter assemblies are used to implant prosthetic devices, such as prosthetic valves, at locations inside the body that are not easily accessible by surgery or where access is required without invasive surgery. For example, minimally invasive surgical techniques can be used to deliver aortic, mitral, tricuspid, and / or pulmonary artery prosthetic valves to the treatment site.

[0004] Percutaneous interventional medicine uses the body's major blood vessels to reach the target site instead of surgically opening it. Many types of disease conditions can be treated with interventional methods, including coronary artery blockage, transcatheter aortic valve replacement (TAVR), and cerebral aneurysms. These techniques involve using guidewires, catheters, balloons, electrodes, and other thin devices to travel along the length of the vessel from the entry point to the target site. The device has a proximal end controlled by the clinician outside the body and a distal end inside the body responsible for treating the disease condition. Percutaneous interventional procedures offer several advantages over open surgical techniques. First, percutaneous interventional procedures require smaller incision sites, which reduces scarring and bleeding and lowers the risk of infection. Percutaneous surgery is also less traumatic to tissues, resulting in shorter recovery times. Finally, percutaneous interventional techniques can generally be performed faster and involve fewer clinicians, thus reducing overall costs. In some cases, anesthesia is also eliminated, further accelerating the recovery process and reducing risks.

[0005] A single procedure typically uses several different guidewires, catheters, and balloons to achieve the desired effect. One tool is inserted at a time, and then each tool is removed sequentially from the entry site. For example, a guidewire is used to track the correct location within the body. Next, a balloon can be used to dilate the narrowed segment of the blood vessel. Finally, the implant can be delivered to the target site. Because catheters are frequently inserted and removed, a guide sheath is used to protect local anatomy and simplify the procedure.

[0006] Guide sheaths are used to safely introduce delivery devices into a patient's vascular system (e.g., the femoral artery). A guide sheath is a conduit that seals onto the blood vessel at the entry site to reduce vascular bleeding and trauma caused by catheters with rough edges. A guide sheath typically has an elongated cannula that inserts into the vascular system, and a housing that houses one or more sealing valves that allow the delivery device to be positioned in fluid communication with the vascular system with minimal blood loss. Once the guide sheath is positioned within the vascular system, the shaft of the delivery device, carrying the prosthetic device, is advanced through the sheath into the vascular system. Inflatable guide sheaths, formed of highly elastic materials, allow for vascular dilation through the prosthetic device.

[0007] The force required to advance the delivery system / medical device through the sheath is attributed to friction between the sheath and the delivery device, the force required to radially expand the sheath, and the force required to expand adjacent patient anatomy structures (e.g., the femoral vessels). High thrust leads to physician fatigue and errors, and increases the time required to complete the procedure.

[0008] The thrust required to advance a delivery system and / or medical device through the sheath depends on a number of factors, including patient anatomy, the curled valve / delivery system profile, and sheath design / manufacturing. For example, inflatable sheaths, formed of highly elastic materials and some including one or more folds to aid expansion, expand as the implantable device is inserted through the sheath. These sheaths may include strain-relieving portions that extend along / across the outer surface of the sheath (e.g., at the proximal end) and form a smooth transition from the sheath hub to the sheath. The strain-relieving portions limit the expansion of the underlying sheath and help ensure hemostasis between the portion of the sheath inside the patient and the sheath hub (outside the patient). Because the strain-relieving portions resist expansion, higher thrust is required when the delivery device / system and implant are introduced into and advanced through the sheath / strain-relieving portions. Furthermore, recent trends regarding heart valves including thicker PVL skirts have increased the curled profile of the heart valve / delivery device and can result in higher thrust through the sheath, particularly the strain-relieving portions.

[0009] One approach to reducing the thrust required to advance the delivery device through the sheath is to pre-expand the sheath and / or strain-relief portion by passing a relatively large dilator (e.g., a 22 French dilator) through it. This is done during sheath preparation, before the sheath is inserted into the patient, and / or after the sheath is at least partially inserted. The challenge with this approach is that advancing the dilator into the sheath can be difficult given the user's physical strength (i.e., grip strength and arm strength). Additionally, it is important that the dilator completely passes through the distal end of the sheath while avoiding splitting the sheath and / or the distal end of the sheath, which can lead to difficulty or vascular injury during delivery device insertion / removal.

[0010] Therefore, there remains a need for devices, systems, and methods that include a strain-relief portion of the sheath that allows the sheath body to expand, thereby reducing initial thrust when introduced into the delivery system and implant. Summary of the Invention

[0011] Embodiments of the expandable sheath system of the present invention minimize vascular trauma and damage to the sheath and prosthetic device by reducing the thrust required to penetrate the sheath. Some embodiments ensure that the sheath is not damaged during expansion or expansion strain relief. Some embodiments may include a sheath with a smaller profile than that of existing guide sheaths. Furthermore, because less thrust is required and only one sheath is used, rather than several sheaths of different sizes, some embodiments can reduce the length of surgical procedures and decrease the risk of longitudinal or radial vascular tears or plaque displacement.

[0012] This disclosure describes an embodiment of a method for manufacturing a pre-expandable, inflatable sheath for delivering a medical device. In one of its basic configurations / implementations, this disclosure provides a method comprising: providing a radially inflatable sheath having a tubular strain-relief layer; providing a restraining member above the sheath for limiting expansion; expanding the sheath; and removing the restraining member. This basic configuration / implementation may preferably include one or more of the features described elsewhere herein, particularly those features in the examples described below. However, it should be understood that, in addition to or in lieu of the features in the examples described below, the basic configuration / implementation may also preferably include one or more of the features shown in and / or described in conjunction with the accompanying drawings.

[0013] In some embodiments, the method includes providing a radially expandable sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a body portion, and having a folded portion extending along the length of the inner layer; a tubular strain relief layer disposed above the proximal portion of the inner layer; wherein at least a portion of the sheath is configured (e.g., in response to an outwardly directed radial force applied to the lumen by an expansion element of an expander and / or medical device) to partially expand from an unexpanded configuration of the lumen having a first diameter to an expanded configuration of the lumen having a larger second diameter, and then (e.g., to at least partially partially contract back to the unexpanded configuration as the expander and / or medical device passes through the lumen).

[0014] In some embodiments, the method includes providing a constraint member positioned above the distal end of the strain-relief layer, which restricts expansion of adjacent (e.g., below) portions of at least one of the inner layer and the strain-relief layer. For example, in some embodiments, the constraint member restricts the expansion / unfolding of the folded portion, thereby preventing the seam from axially expanding or further radially opening after pre-expansion.

[0015] In some embodiments, the method includes introducing a dilator into the proximal end of the lumen of the sheath, the dilator including a dilating element disposed thereon.

[0016] In some embodiments, the method includes advancing an expander through a proximal portion of the inner layer, such that an expansion element disposed on the expander applies an outwardly radial force to the lumen, and causing the inner layer (and / or strain relief layer) near the expansion element to locally expand from the unexpanded configuration to the expanded configuration.

[0017] In some implementations, the constraint member restricts the expansion of the sheath (e.g., the inner layer and the strain relief layer) in the vicinity of the constraint member.

[0018] In some embodiments, the method includes heating the sheath. For example, in some embodiments, the method includes sterilizing the sheath and / or heat-shaping the sheath into an expanded-folded configuration.

[0019] In some implementations, as the sheath moves from an unexpanded configuration to an expanded configuration during the advance of the expander through the proximal portion of the inner layer, the restraining member restricts the unfolding of the folded portion of the inner layer near the restraining member.

[0020] In some embodiments, the restraint member is positioned across the length of the sheath at a location corresponding to the distal end of the strain relief layer, and extends along the length of the strain relief layer from the distal end toward the proximal end of the strain relief layer, and extends along a second length of the sheath from the distal end of the strain relief layer toward the distal end of the sheath.

[0021] In some embodiments, providing a restraining member above the sheath includes attaching the restraining member to (e.g., releasably attaching it to) at least one of an inner layer or a strain relief layer.

[0022] In some embodiments, the inner surface of the restraint member includes an adhesive (e.g., a temporary / releasable adhesive) for attaching the restraint member to the sheath.

[0023] In some embodiments, the constraint member includes a shrink tube, wherein attaching the constraint member to at least one of the inner layer or the strain relief layer includes providing the constraint member with a shrinkage process (e.g., a shrinkage heating process).

[0024] In some implementations, the method further includes removing the constraint members from the inner layer and the strain relief layer.

[0025] In some implementations, the restraints are removed after the heating step. For example, in some implementations, the restraints are removed just before the start of the medical procedure.

[0026] In some implementations, the constraint members are removed before the heating step.

[0027] In some embodiments, a release feature is incorporated into a package whose size and configuration are designed to receive the sheath, wherein providing a radially expandable sheath includes removing the sheath from the package, wherein removing the sheath from the package removes the restraint members from the inner layer and the strain relief layer.

[0028] In some embodiments, advancing the expander through the proximal portion of the inner layer includes aligning the expansion element of the expander with the distal end of the strain-relieving layer, such that the distal end of the strain-relieving layer is expanded. For example, in some embodiments, the proximal end of the tapered portion of the expander shaft and / or the distal end of the main body portion are aligned with the distal end of the strain-relieving layer.

[0029] In some embodiments, advancing the expander through the proximal portion of the inner layer includes advancing the expansion element of the expander beyond the distal end of the strain-relieving layer, such that the distal end of the strain-relieving layer and a portion of the body portion of the inner layer expand. For example, in some embodiments, the expansion element is used to expand / inflate the length of the body portion of the sheath, which extends 10 mm to 15 mm beyond the distal end of the strain-relieving layer.

[0030] In some embodiments, expanding a portion of the body portion beyond the strain relief layer causes the corresponding length of the folded portion to unfold at least partially. For example, in some embodiments, expanding a portion of the body portion beyond the strain relief layer causes any bonding between the folded layers of the inner layer of the sheath to separate.

[0031] In some embodiments, the method further includes removing the expander from the lumen of the sheath after the heating step is completed. In some embodiments, the expander remains within the sheath during the heating step.

[0032] In some embodiments, the method further includes removing the expander from the lumen of the sheath prior to the heating step.

[0033] In some embodiments, at least a portion of the strain relief layer is configured to (e.g., due to outward radial forces exerted on the lumen of the inner layer by the expander and / or medical device against the inner layer) partially expand from an unexpanded configuration of a first diameter to an expanded configuration of a larger second diameter, and then (e.g., as the expander and / or medical device passes through the lumen) at least partially partially contract back to the unexpanded configuration.

[0034] In some embodiments, at least a portion of the strain relief layer is configured to partially expand from an unexpanded configuration to an expanded configuration in response to an outwardly directed radial force applied to the lumen (e.g., the inner layer) by the expander, and then at least partially contract back to an unexpanded configuration as the expander moves within the lumen, wherein at least a portion of the sheath is configured to partially expand from an unexpanded configuration to an expanded configuration in response to an outwardly directed radial force applied to the lumen of the inner layer by the expander, and then at least partially contract back to an unexpanded configuration as the expander moves within the lumen.

[0035] In some embodiments, the sheath further includes an outer layer disposed above the inner layer, wherein the outer layer is discontinuous and includes an overlapping portion and a lower portion, and the overlapping portion overlaps with the lower portion, wherein at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the lower portion, and wherein the strain relief layer extends at least partially above the outer layer.

[0036] In some embodiments, in the uninflated configuration, the folded portion extends circumferentially above the outer surface of the inner and / or outer layers, wherein in the inflated configuration, the partial inflating causes the length of the folded portion to be at least partially unfolded, and wherein in the inflated configuration, the partial inflating of the sheath causes the length of the overlapping portion to be circumferentially moved relative to the underlying portion.

[0037] In some embodiments, in the expansion configuration, the partial expansion of the sheath forms a gap between the longitudinally extending edges of the outer layer, wherein at least a portion of the expanded portion extends into the gap, and wherein the restraining member limits the expansion of the sheath and the width of the gap near the restraining member.

[0038] In some embodiments, the sheath further includes a resilient outer cover extending at least partially above the sheath (e.g., at least partially above the inner, outer, and / or strain-relieving layers, and below the restraint member when included), wherein the outer cover locally expands and contracts as the medical device is advanced through the lumen, wherein the resilient outer cover applies a radially inward force on the sheath (e.g., pushing the inner, outer, and / or strain-relieving layers toward an unexpanded configuration).

[0039] In some embodiments, the sheath further includes a sheath hub fixedly coupled to a proximal end of the sheath, the sheath hub including a central lumen extending through and coaxial with the lumen of the sheath, wherein the size and configuration of the expander shaft are designed to be received (e.g., slidably received) within the central lumen of the sheath hub, wherein the expander includes an expander hub coupled to a proximal end of the expander shaft, wherein the method further includes: advancing the expander through the proximal portion until the expander hub abuts against the sheath hub; and coupling the expander hub to the sheath hub before heating the sheath. For example, in some embodiments, the expander hub is coupled to the sheath hub by press fit, interference fit, snap fit, pin, thread, bayonet fastener, clip, and / or locking key.

[0040] In some embodiments, heating the sheath includes heating the sheath at a temperature and duration corresponding to the sterilization process, wherein, during heating, the sheath is not heated to a temperature or duration sufficient to bond the layers of the folded portion.

[0041] In some embodiments, heating the sheath involves heating the sheath at a temperature of 60°C.

[0042] In some embodiments, heating the sheath includes heating the sheath for a duration longer than 12 hours (e.g., heating at 60°C for 24 hours, heating at 60°C for 26 hours).

[0043] Another embodiment of this disclosure is a sheath system comprising: a radially expandable sheath including: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a main portion, and a folded portion extending along the length of the inner layer. In some embodiments, the expandable sheath includes a tubular strain-relieving layer disposed above the proximal portion of the inner layer. In some embodiments, the expandable sheath includes a restraining member positioned above a distal end of the strain-relieving layer, the restraining member limiting the expansion of adjacent (e.g., below) portions of at least one of the inner layer and the strain-relieving layer (e.g., limiting the expansion / unfolding of the folded portion, thereby preventing axial expansion or further radial opening of the seam formed between the outer and inner layers and / or between adjacent layers of the folded portion after pre-expansion). In some embodiments, the sheath system also includes an expander sized and configured to be received within the lumen of the inner layer, the expander including an elongated expander shaft and an expansion element disposed thereon. In some embodiments, at least a portion of the sheath (e.g., the inner layer and / or strain-relieving layer) is configured to partially expand from an unexpanded configuration with a first diameter to an expanded configuration with a larger second diameter in response to an outwardly directed radial force applied to the lumen by the expansion element of the expander (and / or medical device), and then at least partially contract back to the unexpanded configuration as the expander (and / or medical device) passes through the lumen. In some embodiments, a restraining member limits the expansion of the sheath (e.g., the inner layer and / or strain-relieving layer) in the vicinity of the restraining member.

[0044] In some implementations, when the sheath moves from the unexpanded configuration to the expanded configuration, the restraining member restricts the unfolding of the inner folded portion near the restraining member.

[0045] In some embodiments, the restraint member is positioned across the length of the sheath at a location corresponding to the distal end of the strain relief layer, and extends along the length of the strain relief layer from the distal end toward the proximal end of the strain relief layer, and extends along a second length of the sheath from the distal end of the strain relief layer toward the distal end of the sheath.

[0046] In some embodiments, the restraining member includes at least one of a belt, a shrink tube, an elastic tube, or a packaging feature.

[0047] In some embodiments, the restraining member is coupled to (e.g., releasably coupled to) a sheath. For example, in some embodiments, the restraining member is coupled to an inner layer and / or a strain relief layer.

[0048] In some embodiments, the inner surface of the restraint member includes an adhesive (e.g., a temporary / releasable adhesive) for attaching the restraint member to the sheath.

[0049] In some embodiments, the restraint member includes a shrink tube, wherein the restraint member is coupled to at least one of the inner layer or the strain relief layer via a shrinkage process (e.g., a shrinkage heating process).

[0050] In some embodiments, the constraint member includes a release feature for removing the constraint member from the sheath (e.g., the inner layer and / or strain relief layer).

[0051] In some embodiments, the release feature includes at least one of a weakened portion or pull tab and / or a line integral with the restraining member. For example, in some embodiments, the release feature includes a perforation, a notch, and / or a slit.

[0052] In some implementations, the release feature is incorporated into a package whose size and configuration are designed to receive the sheath, wherein removing the sheath from the package removes the restraint member from the inner layer and strain relief layer.

[0053] In some embodiments, the expander shaft includes a main body portion adjacent to a proximal end of the expander shaft and a tapered portion extending from a distal end of the expander shaft toward the main body portion, wherein the expansion element is disposed on the main body portion.

[0054] In some implementations, the expansion element is defined by the main body portion of the expander shaft.

[0055] In some embodiments, the expansion element includes a protrusion extending from the outer surface of the expander shaft. For example, in some embodiments, the expansion element may include a regular or irregularly shaped protrusion extending from the outer surface of the expander shaft. For example, in some embodiments, the protrusion extends around all or part of the circumference of the expander shaft.

[0056] In some embodiments, the diameter of the expansion element is 22F. For example, in some embodiments, the expansion element of the expander has a diameter in the range of 12F to 24F, 14F to 24F, or 14F to 22F.

[0057] In some embodiments, at least a portion of the strain relief layer is configured to (e.g., due to outward radial forces exerted on the lumen of the inner layer by the expander and / or medical device against the inner layer) partially expand from an unexpanded configuration of a first diameter to an expanded configuration of a larger second diameter, and then (e.g., as the expander and / or medical device passes through the lumen) at least partially partially contract back to the unexpanded configuration.

[0058] In some embodiments, at least a portion of the strain relief layer is configured to locally expand from an unexpanded configuration to an expanded configuration in response to an outwardly directed radial force applied to the lumen (e.g., the inner layer) by the expander, and then at least partially contract back to the unexpanded configuration as the expander moves within the lumen.

[0059] In some embodiments, the strain relief layer includes: a proximal portion adjacent to a proximal end of the strain relief layer; a distal portion adjacent to a distal end of the strain relief layer; and a tapered portion extending between the distal portion and the proximal portion, wherein the diameter of the proximal portion is larger than the diameter of the distal portion.

[0060] In some implementations, the strain relief layer comprises a material that is harder and / or less elastic than the inner layer and restricts the expansion of the inner layer.

[0061] In some embodiments, the strain relief layer comprises a material with a higher hardness than the inner layer, such that the strain relief layer restricts the expansion of the sheath (e.g., the inner and / or outer layers).

[0062] In some embodiments, the strain-relieving layer comprises polyurethane. For example, in some embodiments, the strain-relieving layer comprises high-density polyethylene.

[0063] In some implementations, the length of the strain relief layer remains constant as it moves from the unexpanded configuration to the expanded configuration.

[0064] In some embodiments, the sheath further includes: an outer layer disposed above the inner layer; wherein the strain relief layer comprises a material that is harder and / or less elastic than the inner and outer layers, and restricts the expansion of at least one of the inner or outer layers, wherein the strain relief layer comprises a material that is harder than the inner and / or outer layers, such that the strain relief layer restricts the expansion of at least one of the inner or outer layers.

[0065] In some embodiments, the sheath further includes an outer layer disposed above the inner layer, wherein the outer layer is discontinuous and includes an overlapping portion and a lower portion, and the overlapping portion overlaps with the lower portion, wherein at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the lower portion, and wherein the strain relief layer extends at least partially above the outer layer.

[0066] In some embodiments, in the unexpanded configuration, the folded portion extends circumferentially above the outer surface of the inner and / or outer layers.

[0067] In some embodiments, in the expansion configuration, local expansion causes the length of the folded portion to expand at least partially, thereby forming the expanded portion of the inner layer, wherein in the expansion configuration, the local expansion of the sheath causes the length of the overlapping portion to move circumferentially relative to the lower portion.

[0068] In some embodiments, in the expansion configuration, the partial expansion of the sheath forms a gap between the longitudinally extending edges of the outer layer, wherein at least a portion of the expanded portion extends into the gap, and wherein the restraining member limits the expansion of the sheath and the width of the gap near the restraining member.

[0069] In some embodiments, the total length of the strain relief layer and / or sheath does not change when the sheath and / or strain relief layer move between an unexpanded configuration and an expanded configuration.

[0070] In some implementations, the inner lumen is cylindrical in both the unexpanded and expanded configurations.

[0071] In some implementations, the inner layer comprises PTFE and the outer layer comprises HDPE and / or Tecoflex.

[0072] In some implementations, the inner and outer layers are combined together.

[0073] In some implementations, the inner and outer layers are thermally bonded together.

[0074] In some implementations, the inner and outer layers are bonded together with an adhesive.

[0075] In some implementations, the strain relief layer is bonded to the outer and / or inner layers.

[0076] In some implementations, the strain relief layer is thermally bonded and / or adhesively bonded to the outer and / or inner layers.

[0077] In some implementations, the inner layer comprises woven fabric and / or braided filaments.

[0078] In some embodiments, the inner layer comprises yarn filaments of PTFE, PET, PEEK, and / or nylon.

[0079] In some implementations, the outer layer comprises polyurethane (e.g., high-density polyethylene).

[0080] In some embodiments, the sheath system further includes a resilient outer cover extending at least partially over the sheath (e.g., at least partially over the inner, outer, and / or strain-relieving layers), wherein the outer cover locally expands and contracts as the expander (and / or medical device) is advanced through the lumen. In some embodiments, the resilient outer cover applies a radially inward force to the sheath (e.g., pushing the inner, outer, and / or strain-relieving layers toward an unexpanded configuration). In some embodiments, the resilient outer cover comprises PEBAX, polyurethane, siloxane, or polyisoprene, or combinations thereof.

[0081] In some embodiments, the sheath further includes a sheath hub fixedly coupled to a proximal end of the sheath. In some embodiments, the sheath hub includes a central lumen extending through and coaxial with the lumen of the sheath, wherein the size and configuration of the expander shaft are designed to be received (e.g., slidably received) within the central lumen of the sheath hub. In some embodiments, the expander includes an expander hub coupled to a proximal end of the expander shaft, wherein the expander hub is configured to be coupled to the sheath hub. For example, in some embodiments, the expander hub is coupled to the sheath hub by press fit, interference fit, snap fit, pin, thread, bayonet fastener, clip, and / or locking key.

[0082] In some embodiments, the sheath hub includes one or more seals for forming a seal around the outer surface of a delivery device that is movable through the central lumen of the sheath hub.

[0083] Another embodiment of this disclosure provides a sheath kit system comprising: a radially expandable sheath, the radially expandable sheath including: In some embodiments, the expandable sheath includes a continuous inner layer defining a lumen passing through it, the inner layer including a proximal portion and a body portion and a folded portion extending along the length of the inner layer. In some embodiments, the expandable sheath includes a tubular strain-relieving layer disposed above the proximal portion of the inner layer and a restraining member positioned above a distal end of the strain-relieving layer, the restraining member restricting expansion of adjacent (e.g., below) portions of at least one of the inner layer and the strain-relieving layer. For example, in some embodiments, the restraining member restricts the expansion / unfolding of the folded portion, thereby preventing the seam from axially expanding or further radially opening after pre-expansion. In some embodiments, the sheath kit system also includes an expander sized and configured to be received within the lumen of the inner layer, the expander including an elongated shaft and an expansion element disposed thereon. In some embodiments, the sheath kit system includes a tray sized and configured to receive the sheath and expander. The tray includes a release mechanism coupled to a restraining member, wherein, upon removal of the sheath from the tray, the release mechanism retains the restraining member, thereby removing it from the sheath. In some embodiments, at least a portion of the sheath (e.g., the inner layer and / or strain-relieving layer) is configured to partially expand from an unexpanded configuration of the lumen having a first diameter to an expanded configuration of the lumen having a larger second diameter in response to an outwardly directed radial force applied to the lumen by the expansion element of the expander (and / or medical device), and then at least partially contract back to the unexpanded configuration as the expander (and / or medical device) passes through the lumen. In some embodiments, the restraining member limits the expansion of the sheath (e.g., the inner layer and strain-relieving layer) in the vicinity of the restraining member.

[0084] Another embodiment of this disclosure provides a method for delivering a medical device via a sheath. In some embodiments, the method includes providing a radially expandable sheath having a continuous inner layer defining a lumen passing through it, wherein the inner layer includes a proximal portion and a body portion, and a folded portion extending along the length of the inner layer. In some embodiments, the expandable sheath includes a tubular strain-relieving layer disposed above the proximal portion of the inner layer and a restraining member positioned above a distal end of the strain-relieving layer, wherein the restraining member restricts expansion of adjacent (e.g., below) portions of at least one of the inner layer and the strain-relieving layer. For example, in some embodiments, the restraining member restricts the expansion / unfolding of the folded portion, thereby preventing the seam from axially expanding or further radially opening after pre-expansion. In some embodiments, the method further includes removing an expander received from the lumen of the inner layer, wherein the restraining member restricts the expansion of the sheath (e.g., the inner layer and / or the strain-relieving layer) due to an outwardly pointing radial force applied by the expander. In some embodiments, the method includes removing the restraining member from the sheath. In some embodiments, the method includes introducing a medical device into the proximal end of the central lumen of a sheath; advancing the medical device through a proximal portion of the inner layer (e.g., a portion of the sheath corresponding to the strain-relieving layer), thereby applying an outwardly pointing radial force by the medical device to the central lumen (e.g., the inner layer), such that the strain-relieving layer near the inner layer and the medical device partially expands from an unexpanded configuration to an expanded configuration, and that the strain-relieving layer partially contracts toward the unexpanded configuration as the medical device passes through the corresponding portion of the lumen of the sheath. In some embodiments, the method includes advancing the medical device beyond the distal end of the strain-relieving layer and advancing the medical device through the body portion of the lumen of the sheath, such that the body portion of the sheath partially expands from an unexpanded configuration to an expanded configuration at a location near the medical device in response to the outwardly pointing radial force of the medical device applied to the inner layer, that the sheath at least partially contracts back to the unexpanded configuration as the medical device passes through the lumen, and advancing the medical device beyond a distal opening in the sheath.

[0085] In some embodiments, at least a portion of the sheath (e.g., the inner layer and / or strain relief layer) is configured to partially expand from an unexpanded configuration with a first diameter to an expanded configuration with a larger second diameter in response to an outwardly directed radial force applied to the lumen by the expansion element of the expander (and / or medical device), and then at least partially contract back to the unexpanded configuration as the expander (and / or medical device) passes through the lumen.

[0086] Another embodiment of this disclosure provides a method of inserting a medical device into a patient's blood vessel. In some embodiments, the method includes providing a radially expandable sheath having a continuous inner layer defining a lumen passing through it, the inner layer including a proximal portion and a body portion, and a folded portion extending along the length of the inner layer. In some embodiments, the expandable sheath includes a tubular strain-relieving layer disposed above the proximal portion of the inner layer and a restraining member positioned above a distal end of the strain-relieving layer, wherein the restraining member restricts expansion of adjacent (e.g., below) portions of at least one of the inner layer and the strain-relieving layer. For example, in some embodiments, the restraining member restricts the expansion / unfolding of the folded portion, thereby preventing the seam from axially expanding or further radially opening after pre-expansion. In some embodiments, the method further includes removing an expander received from the lumen of the inner layer, wherein the restraining member restricts the expansion of the sheath (e.g., the inner layer and / or the strain-relieving layer) due to an outwardly pointing radial force applied by the expander. In some embodiments, the method includes removing the restraining member from the sheath. In some embodiments, the method includes inserting a sheath at least partially into a patient's blood vessel; introducing a medical device into the proximal end of the central lumen of the sheath. In some embodiments, the method includes advancing the medical device through a proximal portion of the inner layer (e.g., a portion of the sheath corresponding to the strain-relieving layer), thereby applying an outwardly pointing radial force by the medical device to the central lumen (e.g., the inner layer), such that the strain-relieving layer near the inner layer and the medical device locally expands from a non-expanded configuration to an expanded configuration, and locally contracts towards the non-expanded configuration as the medical device passes through the corresponding portion of the lumen of the sheath; advancing the medical device beyond the distal end of the strain-relieving layer. In some embodiments, the method includes advancing the medical device through the lumen of the body portion of the sheath, such that the body portion of the sheath locally expands from a non-expanded configuration to an expanded configuration at a location near the medical device in response to an outwardly pointing radial force of the medical device applied to the inner layer, and at least partially contracts the sheath back to the non-expanded configuration as the medical device passes through the lumen; and advancing the medical device beyond a distal opening in the sheath to reach a treatment site within the blood vessel.

[0087] In some implementations, the expander expands the distal end of the strain relief layer.

[0088] In some embodiments, the inner layer includes at least one folded portion, wherein local expansion of the lumen of the sheath causes the length of the folded portion to unfold at least partially.

[0089] In some embodiments, the sheath further includes an outer layer disposed above the inner layer, wherein the outer layer is discontinuous and includes an overlapping portion and a lower portion.

[0090] In some embodiments, when the sheath is in its uninflated configuration, the overlapping portion overlaps with the lower portion, wherein the folded portion of the inner layer is disposed between the overlapping portion and the lower portion. In some implementations, the strain relief layer extends at least partially over the outer layer.

[0091] In some implementations, the medical device is a prosthetic device mounted on a delivery device in a radially curled state.

[0092] In some embodiments, advancing the prosthetic device through the lumen of the sheath includes advancing the delivery device through the lumen of the sheath and into the patient's vascular system.

[0093] In some embodiments, the prosthetic device includes a prosthetic heart valve, and the method further includes implanting the prosthetic heart valve into a treatment site within the patient's body.

[0094] In some implementations, the prosthetic heart valve is mounted on the balloon catheter of the delivery device as it is advanced through the sheath.

[0095] In some implementations, the sheath is inserted into the patient's femoral artery.

[0096] The various aspects of the above embodiments can be combined based on the desired sheath system characteristics. Attached Figure Description

[0097] FIG. 1 This is a front view of an expandable sheath and an intravascular delivery device for implanting prosthetic implants.

[0098] FIG. 2 It is a front view including the guide lock hub, the sheath lock sleeve, and the expandable sheath of the guide.

[0099] FIG. 3 yes FIG. 2 A front view of the expandable sheath and the intravascular delivery device for implanting prosthetic implants.

[0100] FIG. 4 yes FIG. 2 Front view of the expandable sheath, sheath hub, guide locking hub and sheath locking sleeve.

[0101] FIG. 5A yes FIG. 2 A cross-sectional view of the sheath hub, guide lock hub, and sheath lock sleeve.

[0102] FIG. 5B yes FIG. 2 A cross-sectional view of the guide cap, sheath hub, guide locking hub, and sheath locking sleeve.

[0103] FIG. 6 yes FIG. 2 A cross-sectional view of the guide cap, sheath hub, guide locking hub, and sheath locking sleeve.

[0104] FIG. 7 yes FIG. 2 Sheath locking sleeve and FIG. 5A-5B A view of the distal end of the proximal fluid seal.

[0105] FIG. 8A It is connected to the guide. FIG. 2 First front view of the guide lock hub.

[0106] FIG. 8B It is connected to the guide. FIG. 2 The second (rotated) front view of the guide lock hub.

[0107] FIG. 8C It is connected to the guide. FIG. 2 A view of the distal end of the guide lock hub.

[0108] FIG. 8D It is connected to the guide. FIG. 2 A partial side view of the guide lock hub.

[0109] FIG. 8E It is connected to the guide. FIG. 2 A partial perspective view of the guide lock hub.

[0110] FIG. 8F It is connected to the guide. FIG. 2 A partial perspective view of the guide lock hub.

[0111] FIG. 9A yes FIG. 2 A view of the distal end of the guide lock hub.

[0112] FIG. 9B yes FIG. 2 First front view of the guide lock hub.

[0113] FIG. 9C yes FIG. 2 A view of the proximal end of the guide lock hub.

[0114] FIG. 9D yes FIG. 2 First perspective view of the guide lock hub.

[0115] FIG. 9E yes FIG. 2 The second front view of the guide lock hub.

[0116] FIG. 9F yes FIG. 2 Second perspective view of the guide lock hub.

[0117] FIG. 10A yes FIG. 2 A view of the distal end of the sheath locking sleeve.

[0118] FIG. 10B yes FIG. 2 First front view of the sheath locking sleeve.

[0119] FIG. 10C yes FIG. 2 A view of the proximal end of the sheath locking sleeve.

[0120] FIG. 10D yes FIG. 2 First perspective view of the sheath locking sleeve.

[0121] FIG. 10E yes FIG. 2 The second front view of the sheath locking sleeve.

[0122] FIG. 10F yes FIG. 2 Second perspective view of the sheath locking sleeve.

[0123] FIG. 11 yes FIG. 1 and FIG. 2 A side sectional view of a portion of an expandable sheath.

[0124] FIG. 12 yes FIG. 1 and FIG. 2 An enlarged view of a portion of the expandable sheath.

[0125] FIG. 13A yes FIG. 1 and FIG. 2 An enlarged view of a portion of the expandable sheath, with the outer layer removed for illustrative purposes.

[0126] FIG. 13B yes FIG. 1 and FIG. 2 A magnified view of a portion of the woven layer of the sheath.

[0127] FIG. 14 yes FIG. 1 and FIG. 2 An enlarged view of a portion of the expandable sheath, illustrating the expansion of the sheath as the prosthetic device is advanced through it.

[0128] FIG. 15 yes FIG. 1 and FIG. 2 Side view of the expandable sheath.

[0129] FIG. 16 yes FIG. 15Enlarged sectional view of the sheath along section line 16-16.

[0130] FIG. 17 yes FIG. 16 A sectional view of the unexpanded sheath along section line 17-17.

[0131] FIG. 18 yes FIG. 15 A sectional view of the unexpanded sheath along section line 18-18.

[0132] FIG. 19 yes FIG. 15 A sectional view of the unexpanded sheath along section line 19-19.

[0133] FIG. 20 yes FIG. 15 The expansion sheath is shown in a sectional view along section line 19-19.

[0134] FIG. 21 yes FIG. 1 and FIG. 2 Side view of the expandable sheath.

[0135] FIG. 22 yes FIG. 21 A cross-sectional view of the unexpanded sheath along section line 22-22.

[0136] FIG. 23 yes FIG. 21 The expansion sheath is shown in a sectional view along section line 22-22.

[0137] FIG. 24 This is a side view of an example sheath system.

[0138] FIG. 25 This is a top view of an example sheath system included in the corresponding packaging pallet. Detailed Implementation

[0139] The following description of certain examples of the inventive concept is not intended to limit the scope of the claims. Other examples, features, aspects, embodiments, and advantages will become apparent to those skilled in the art from the following description. It will be appreciated that the apparatus and / or method can have other different and obvious aspects without departing from the spirit of the inventive concept. Therefore, the drawings and description should be considered illustrative in nature and not restrictive.

[0140] For the purposes of this description, certain aspects, advantages, and novel features of embodiments of this disclosure are described herein. The described methods, systems, and apparatuses should not be construed as limiting in any way. Rather, this disclosure relates to all novel and non-obvious features and implementations of the various disclosed embodiments, individually and in various combinations and sub-combinations with each other. The disclosed methods, systems, and apparatuses are not limited to any particular aspect, feature, or combination thereof, nor are they required to provide any one or more particular advantages or solve any one or more particular problems.

[0141] Features, integrals, properties, compounds, chemical parts, or groups described in conjunction with specific aspects or examples of this disclosure should be understood to be applicable to any other aspect or example described herein, unless incompatible with it. All features disclosed in this specification (including any appended claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except for at least some mutually exclusive combinations of such features and / or steps. This disclosure is not limited to the details of any of the foregoing embodiments. This disclosure extends to any novel feature or any combination of novel features disclosed in this specification (including any appended claims, abstract, and drawings), or to any novel step or any combination of novel steps in any method or process so disclosed.

[0142] It should be understood that any patent, publication, or other disclosure referred to as incorporated herein by reference is incorporated in whole or in part only to the extent that the incorporated material does not conflict with the existing definitions, statements, or other disclosures set forth in this disclosure. Therefore, and to the extent necessary, any conflicting material incorporated by reference shall supersede the disclosure expressly set forth herein. Any material or portion thereof referred to as incorporated herein by reference that conflicts with the existing definitions, statements, or other disclosures set forth herein shall be incorporated only to the extent that such incorporated material does not conflict with the existing disclosures.

[0143] As used in the specification and appended claims, the singular forms “a,” “an,” and “the” include plural indicators unless the context clearly specifies otherwise. A range herein may be expressed as from “about” one particular value and / or to “about” another particular value. When such a range is expressed, the other side includes from one particular value and / or to another particular value. Similarly, when a value is expressed as an approximation using the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that each endpoint of a range is significant relative to and independent of the other endpoint.

[0144] "Optional" or "optionally" means that the event or situation described below may or may not occur, and the description includes instances where the event or situation occurs and instances where the event or situation does not occur.

[0145] As used herein, the terms “proximal” and “distal” refer to the areas of the sheath, catheter, or delivery assembly. “Proximal” means the area closest to the handle of the device, while “distal” means the area furthest from the handle of the device.

[0146] As used in this article, “axial” or “axial” refers to the direction along the longitudinal axis of the sheath.

[0147] Throughout the description and claims of this specification, the word "comprise" and variations thereof, such as "comprising" or "comprises," mean "including but not limited to" and are not intended to exclude, for example, other additives, components, integers, or steps. "Exemplary" means "an instance of..." and is not intended to convey indications of preferred or ideal aspects. "Like" is not used in a limiting sense but for interpretive purposes.

[0148] The disclosed embodiment of the expandable sheath minimizes trauma to the blood vessels by allowing a portion of the guide sheath to temporarily expand to accommodate the delivery system, subsequently returning to its original diameter after the device has passed through. The disclosed embodiment of the guide sheath prevents the guide from separating from the sheath during insertion by locking the proximal hub of the guide to the proximal hub of the sheath. Fixing the guide and sheath prevents posterior movement of the guide during insertion, thereby maintaining a tight fit and smooth transition between the distal ends of the guide and sheath. Furthermore, since only one sheath is required, rather than several sheaths of different sizes, embodiments of the invention can reduce the length of surgical procedures and decrease the risk of longitudinal or radial vascular tears or plaque displacement. Embodiments of the expandable sheath of the present invention can avoid the need for multiple insertions for vascular dilation.

[0149] Exemplary expandable guide sheaths are disclosed in, for example, U.S. Patent No. 8,690,936 entitled "Expandable Sheath for Introducing an Endovascular Delivery Device into a Body," U.S. Patent No. 8,790,387 entitled "Expandable Sheath for Introducing an Endovascular Delivery Device into a Body," U.S. Patent No. 10,639,152 entitled "Expandable Sheath and Methods of Using the Same," U.S. Patent No. 10,792,471 entitled "Expandable Sheath," U.S. Patent Application No. 16 / 407,057 entitled "Expandable Sheath with Elastomeric Cross Sectional Portions," U.S. Patent No. 10,327,896 entitled "Expandable Sheath with Elastomeric Cross Sectional Portions," and U.S. Patent No. 11,273,062 entitled "Expandable Sheath." Applications for the purpose of introducing an endovascular delivery device into a body include: PCT / US2021 / 019514 ("Expandable sheath for introducing an endovascular delivery device into a body"), PCT / US2021 / 031227 ("Expandable sheath for introducing an endovascular delivery device into a body"), PCT / US2021 / 031275 ("Expandable sheath for introducing an endovascular delivery device into a body"), and US Application No. 17 / 113,268 ("Expandable Sheath and Method of Using the Same"). The application also includes applications for the purpose of self-expanding...The following patent applications are listed: PCT / US2021 / 058247, entitled "Two Component Sheath"; PCT / US2022 / 012785, entitled "Expandable Sheath"; US Patent No. 11,051,939, entitled "Active Introducer Sheath System"; PCT / US2022 / 012684, entitled "Introducer with Sheath Tip Expander"; US Patent No. 17 / 078,556, entitled "Advanced Sheath Patterns"; PCT / US2021 / 025038, entitled "Low temperature hydrophilic adhesive for use in expandable sheath for introducing an endovascular delivery device into a body"; PCT / US2021 / 050006, entitled "Expandable Sheath Including Reversible Bayonet Locking Hub"; and PCT / US2021 / 050006, entitled "Expandable Sheath Gasket to Provide...". The disclosures of U.S. Provisional Application No. 63 / 280,251 entitled “Hemostasis”, U.S. Provisional Application No. 63 / 530,144 entitled “Introducer / Dilator with Folded Balloon”, and U.S. Provisional Application No. 63 / 502,907 entitled “Lead Screw Driven Sheath Dilator” are incorporated herein by reference.

[0150] The elongated guide sheath disclosed herein is particularly suitable for delivering implantable heart valves, such as balloon-inflatable implantable heart valves. Balloon-inflatable implantable heart valves are well-known and will not be described in detail here. Examples of such implantable heart valves are described in U.S. Patent Nos. 5,411,552 and 9,393,110, which are incorporated herein by reference. The expandable guide sheath disclosed herein can also be used to deliver negotiated implantable medical devices, such as self-expanding and mechanically expandable implantable heart valves, stents, or filters. In addition to transcatheter heart valves, the guide sheath system can be used in other types of minimally invasive procedures, such as any surgical procedure requiring the introduction of a device into a patient's blood vessel. For example, guide sheath systems can be used to introduce other types of delivery devices to place various types of endovascular devices (e.g., stents, stent-supported grafts, balloon catheters for angioplasty, etc.) into various types of vascular and non-vascular lumens (e.g., veins, arteries, esophagus, bile ducts, intestines, urethra, fallopian tubes, other endocrine or exocrine ducts, etc.). As used herein, the term "implantable" is broadly defined to mean anything delivered to a site within the body, whether or not it is a prosthesis. For example, diagnostic devices can be implantable.

[0151] FIG. 1 An exemplary sheath 8 is illustrated for use with a representative delivery device 10 for delivering an implant 12 or other types of implantable devices (e.g., tissue heart valves) to a patient. The delivery device 10 may include a steerable guiding catheter 14 (also referred to as a flexible catheter) and a balloon catheter 16 extending through the guiding catheter 14, and a nasal cannula 15 extending through the balloon catheter 16. In the illustrated example, the guiding catheter 14, balloon catheter 16, and nasal cannula 15 are adapted to slide longitudinally relative to each other to facilitate the delivery and positioning of the implant 12 within the patient's body at an implantation site, as described in detail herein. It is envisioned that the sheath 8 can be used with any type of elongated delivery device for implanting balloon-expandable prosthetic valves, self-expanding prosthetic valves, and other prosthetic devices.

[0152] As described in more detail herein, generally speaking, the sheath 8 includes an elongated, expandable tube that, in use, is inserted into a blood vessel (e.g., via the femoral vessel, femoral artery, or iliac artery) through the patient's skin, such that the distal end of the sheath 8 is inserted into the blood vessel. At the proximal end of the sheath 8, for example in the sheath hub 20, a hemostatic valve and / or sealing feature is included, which provides hemostasis and prevents blood leakage from the patient through the sheath 8. The sheath 8, including the guide 6, is advanced into the patient's vascular system. Once positioned, the guide 6 is removed and the delivery device 10 is inserted / through the sheath 8, and then the prosthetic device (implant 12) is delivered and implanted into the patient.

[0153] like FIG. 2 and FIG. 3 As provided, the guide device / sheath assembly includes a sheath hub 20 at a proximal end of the device and an expandable sheath 8 extending distally from the sheath hub 20. The sheath 8 is coupled to the sheath hub 20, which is then removably coupled to an optional sheath locking system 18. The sheath locking system 18 allows the guide 6 or other desired device to be removably (axially and rotatably) coupled to the sheath 8.

[0154] like FIG. 2-6 As shown, the sheath hub 20 can optionally be used as the handle of the device. The sheath hub 20 also provides a housing for necessary sealing components and an inlet for a secondary lumen (e.g., a fluid lumen) in fluid communication with the central lumen of the sheath hub 20. In some instances, as described herein and as... FIG. 5A , FIG. 5B and FIG. 7 The sealing assembly 24 shown is included within the sheath hub 20. The sealing assembly 24 includes a proximal seal 24a, an intermediate seal 24b, and a distal seal 24c. When assembled, the guide 6 passes through the sealing assembly and extends distally to the sheath 8. The proximal seal 24a, intermediate seal 24b, and distal seal 24c are each configured to prevent unwanted fluid from passing through the sheath hub 20 in a proximal direction and from advancing proximally into the sealing assembly 24. Each seal is openable and closable to provide pressure variations that affect the desired fluid flow from a physician or technician.

[0155] In some embodiments, the distal end of the sheath hub 20 includes threads 21 for engagement with a threaded sheath hub cap 22. A sheath 8 is disposed between the sheath hub 20 and the sheath hub cap 22 such that engaging the sheath hub cap 22 to the sheath hub 20 secures the sheath 8 to the sheath hub 20. The sheath hub cap 22 is a cylindrical cap having a cap body with a proximal end and a distal end, defining a longitudinally extending central lumen between the proximal and distal ends. The diameter of the sheath hub cap 22 at its proximal end is larger than its diameter at its distal end.

[0156] In some embodiments, the sheath hub 20 further includes a receiving slot 48 for engaging the sheath locking system 18, particularly the locking sleeve 28, to the sheath hub 20. In some embodiments, the example receiving slot 48 includes an opening extending around a portion of the diameter of the sheath hub 20, and its size and configuration are designed to receive an interference diameter 66 of the locking sleeve 28. The engagement between the receiving slot 48 and the interference diameter 66 secures the locking sleeve 28 and the sheath hub 20 axially and rotatably relative to each other.

[0157] FIG. 2 ExamplesFIG. 1 The sheath 8 includes an optional sheath locking system 18 for preventing axial and rotational translation of the guide 6 relative to the sheath 8. An example locking system is disclosed in PCT / US2021 / 050006 entitled “Expandable SheathIncluding Reverse Bayonet Locking Hub,” the disclosure of which is incorporated herein by reference. It is contemplated that the locking system 18 disclosed herein may also be optionally used to connect the sheath 8 / sheath hub 20 to other delivery system components, catheters, dilators, etc., including those with the same mating features.

[0158] As described herein, in some embodiments, the sheath locking system 18 is used to secure the guide 6 relative to the sheath 8 during insertion, without requiring a physician or technician to hold the guide 6 and sheath 8 in proper position at the distal end. FIG. 8A-8B As shown, the sheath locking system 18 includes a locking sleeve 28 and a guide locking hub 30 (including a corresponding guide 6). In some embodiments, the locking sleeve 28 is coupled to the sheath 8 via the sheath hub 20. The locking sleeve 28 engages the guide locking hub 30 and is movable between a locked position and an unlocked position, thereby securing the positions of the guide 6 and the sheath 8 and preventing movement between them, particularly during insertion into the patient. As will be described in more detail herein, the sheath locking system 18 can be used to prevent the guide 6 from separating from the sheath 8 and to prevent the formation of gaps that could cause patient abrasions and unintended fluid flow between the guide 6 and the sheath 8 during insertion.

[0159] FIG. 2 , FIG. 5A-5B and FIG. 6 An example is illustrated of a sheath locking sleeve 28 coupled to a guide locking hub 30 and a sheath hub 20. As will be described in more detail herein, in some embodiments, the locking sleeve 28 includes a guide 31 that engages a locking channel 38 disposed on the guide locking hub 30. The guide 31 is configurable within the locking channel 38 in both an unlocked and locked position (in... FIG. 2 (as shown in the figure) can move between, in the unlocked position, the sheath locking sleeve 28 can rotate relative to the guide locking hub 30 and can move axially, in the locked position, the locking sleeve 28 is axially fixed relative to the guide locking hub 30.

[0160] For example in FIG. 10A-10F A locking sleeve 28 is illustrated. The locking sleeve 28 includes an elongated sleeve body 29 having a central lumen 56 extending longitudinally between a proximal end 58 and a distal end 60 of the sleeve body 29. (See illustration.) FIG. 6As shown in the cross-sectional view of the sheath locking system 18, the central lumen 56 defines a generally cylindrical inner surface 62 of the sheath locking sleeve 28. In some embodiments, the central lumen 56 has a diameter of at least 0.3″. In some instances, the diameter ranges between 0.3″ and 0.6″. Preferably, the diameter is about 0.40″. The distal end 60 of the sleeve body 29 optionally has a truncated conical outer surface 64 that tapers around the distal end 60 to help position the locking sleeve 28 within the sheath hub 20 and abut against the sealing assembly 24, such as... FIG. 5A and FIG. 5B (As shown). In some embodiments, the locking sleeve 28 also has a plurality of interference diameters 66 extending radially from all or a portion of the circumference of the locking sleeve 28 around the outer surface of the sleeve body 29. (As shown) FIG. 5A and FIG. 6 As shown, the size and configuration of the interference diameter 66, positioned distally, are designed to engage with corresponding recesses and / or slots 48 provided in the sheath hub 20 for securing the locking sleeve 28 to the sheath hub 20. In some embodiments, such as FIG. 6 As shown, the interference diameter 66, positioned proximally, optionally abuts against the proximal end of the sheath hub 20.

[0161] like FIG. 10B As shown, the locking sleeve 28 includes a guide 31 protruding from the outer surface 68 of the locking sleeve 28. As described herein, the guide 31 is sized to engage a corresponding shaped locking channel 38 in the guide locking hub 30, such as... FIG. 9B As shown. The guide 31 extends radially from the outer surface 68 and at least partially around the circumference of the outer surface 68. FIG. 6 As provided, in some embodiments, when the locking sleeve 28 and the guide locking hub 30 are engaged, the top surface of the guide 31 does not extend beyond the outer surface of the guide locking hub 30. For example, when the sheath locking sleeve 28 and the guide locking hub 30 are engaged, the height of the guide 31 may optionally be designed to correspond to the wall thickness of the guide locking hub 30 near the guide. In another example, the top surface of the guide 31 may optionally be recessed relative to the outer surface of the guide locking hub 30. That is, the height of the guide 31 is less than the wall thickness of the guide locking hub 30. In other examples, the height of the guide 31 may optionally be greater than the wall thickness of the guide locking hub 30, such that when the sheath locking sleeve 28 and the guide locking hub 30 are engaged, the top surface of the guide 31 extends beyond the outer surface of the guide locking hub 30. In some examples, the height / axial length of the guide 31 is between about 0.050″ and about 0.10″. In some instances, the height / axial length of guide 31 is approximately 0.075″.

[0162] likeFIG. 10D-10F As shown, the guide 31 is optionally defined as a cylindrical protrusion. However, it is contemplated that the guide 31 may have any other regular or irregular shape, which would facilitate movement of the guide 31 within the locking channel 38 of the guide locking hub 30. For example, the guide 31 may optionally have an elongated hexagonal shape. The diameter / width of the guide 31 may range from about 0.05″ to about 0.20″. Preferably, the guide 31 has a diameter / width of about 0.100″.

[0163] Generally, the locking sleeve 28 may optionally be formed of polycarbonate. In other embodiments, the locking sleeve 28 may be formed of rigid plastic or any other material suitable for providing a robust locking connector for the guide 6, including, for example, metal, composite material or other suitable material.

[0164] FIG. 2-6 An example is shown of a guide locking hub 30 connected to a locking sleeve 28. FIG. 8A-8F The guide locking hub 30, which is connected to the guide 6, is shown. FIG. 9A-9F Several views of the guide locking hub 30 are provided. As described herein, the guide 6 can be fixedly coupled to the guide locking hub 30. For example, in some embodiments, the guide locking hub 30 is coupled to a locking sleeve 28 to fix the position of the guide 6 (axially and rotatably) relative to the locking sleeve 28 / sheath 8. Each of the guide 6 and the guide locking hub 30 is described in more detail herein.

[0165] FIG. 8A-8F An example is shown of a guide locking hub 30, to which an example guide 6 is coupled. FIG. 5A and FIG. 5B As shown in the cross-sectional view, the guide 6 is coupled to the guide locking hub 30 and extends beyond the distal end of the guide locking hub 30 body. When coupled to the sheath hub 20, the guide 6 extends through the central lumen 56 of the sheath locking cannula 28, the sheath hub 20, and the central lumen of the sheath 8. As described herein, the sheath 8 generally comprises a radially expandable tubular structure. The guide 6 passing through the sheath 8 positioned in the patient's vascular system causes the sheath 8 to expand, and consequently causes the blood vessel to expand radially to the diameter of the sheath 8. That is, the diameter of the central lumen of the sheath 8 generally corresponds to the outer diameter of the guide 6, such that the guide 6 provides a mechanism for expanding / pre-dilatating the patient's blood vessel to receive the medical device / implant 12.

[0166] like FIG. 8A-8F As provided, the guide 6 is formed as an elongated body and optionally includes a central lumen extending therethrough. FIG. 5A and FIG. 5BAs shown, during assembly, the central cavity of the guide 6 is aligned with the central cavity of the guide locking hub 30, the sheath hub 20, and the sheath 8. In some embodiments, such as FIG. 5A and FIG. 5B As provided, the guide 6 is received within a recessed opening 39 on the inner surface of the guide locking hub 30, wherein the recessed opening 39 is axially aligned with the central cavity 45 of the guide locking hub 30. In some embodiments, the guide 6 is fixedly or releasably coupled to the guide locking hub 30 at the recessed opening 39. In some instances, the guide 6 is fixedly coupled to the guide locking hub 30 at the recessed opening 39. In some embodiments, the guide 6 has a diameter corresponding to or smaller than the diameter of the recessed opening 39. The guide 6 can be coupled to the recessed opening 39 of the guide locking hub 30 by at least one of the following coupling processes: press fit, interference fit, snap fit, mechanical fasteners, chemical fasteners (e.g., adhesives), welding, heat treatment, and / or any other suitable coupling process known in the art.

[0167] As described herein, the guide 6 optionally includes a central lumen aligned with a central lumen 45 of the guide locking hub 30. When coupled, this engaged lumen allows surgical instruments and / or medical devices (e.g., guidewires) to pass through and reach the treatment site. In the example system, and as... FIG. 5A and FIG. 5B As provided, the central lumen of the guide 6 has a diameter corresponding to at least a portion of the diameter of the central lumen 45 of the guide locking hub 30. Generally, the corresponding diameter portion is adjacent to the distal end of the central lumen 45. In other embodiments, the diameter of the central lumen 45 at the distal end of the guide locking hub 30 is slightly larger than the diameter through the central lumen of the guide 6. The central lumen 45 may optionally define a tapered portion 41 extending between the proximal and distal ends of the guide locking hub 30, such as... FIG. 6 As shown. The corresponding diameter portion and tapered tapered portion 41 allow for a smooth transition and delivery of surgical instruments and / or medical devices through the guide locking hub 30 and into the central lumen of the guide 6.

[0168] like FIG. 9A-9FAs shown, the guide locking hub 30 includes a hub body 32 having a proximal end 70 and a distal end 72, and optionally defines a central lumen 45 extending therethrough. The hub body 32 has a first (intermediate) portion 33, a second (distal) portion 35 extending distally from the first portion 33, and a third (proximal) portion 37 extending proximally from the first portion 33. The first portion 33 may optionally include a cylindrical recessed opening 39 for receiving and retaining the guide 6 and an outer surface 43. In some examples, the diameter of the recessed opening 39 is between 0.15″ and about 0.25″. In some examples, the diameter of the recessed opening 39 is between 0.17″ and about 0.20″. In some examples, the recessed opening has a diameter of about 0.194″.

[0169] In some embodiments, the third (proximal) portion 37 of the guide locking hub 30 includes a tapered, tapered portion 41 of the central lumen 45. For example... FIG. 6 As shown, the tapered portion 41 is defined as a truncated cone with a gradually decreasing taper / diameter in the direction extending from the proximal end to the distal end of the sheath 8. The tapered portion 41 is envisioned to have a minimum diameter of approximately 0.007” and a maximum diameter of approximately 0.194”.

[0170] like FIG. 5A and FIG. 5B As shown, when engaged, the central cavity 56 of the locking sleeve 28 is aligned with the central cavity 45 of the guide locking hub 30. In some embodiments, the central cavity 56 of the locking sleeve 28 is coaxial with the central cavity 45 of the guide locking hub 30. When engaged, the proximal end of the locking sleeve 28 is received within the central cavity 45 of the guide locking hub 30. Therefore, in some embodiments, the proximal end surface of the locking sleeve 28 is positioned adjacent to a shoulder 50 disposed on the inner surface of the central cavity 45 of the guide locking hub 30. FIG. 5A and FIG. 5BAs shown, the central cavity 45 of the guide lock hub 30 includes a first portion 52 and a second portion 54. The first portion 52 is located near the proximal end of the guide lock hub 30 and defines a first diameter, while the second portion 54 is located near the distal end of the guide lock hub 30 and defines a larger second diameter. The recessed opening 39 of the guide lock hub 30 may optionally be considered as a component of the first portion 52 of the central cavity 45, or as a separate component of the central cavity 45 located between the first (proximal) portion 52 and the second (distal) portion 54. When the locking sleeve 28 and the guide lock hub 30 are engaged, at least a portion of the sleeve body 29 of the sheath locking sleeve 28 is received within the second portion 54 (the larger diameter portion) of the central cavity 45 of the guide lock hub 30. In some embodiments, the central cavity 56 of the sheath locking sleeve 28 is aligned with the central cavity 45 of the guide locking hub 30 such that they are coaxial and form a smooth inner surface along the central cavity of the combination of the guide locking hub 30 and the sheath locking sleeve 28.

[0171] As described herein, the locking sleeve 28 can be coupled to the guide locking hub 30 via an engagement between a guide 31 disposed on the locking sleeve 28 and a locking channel 38 disposed in the guide locking hub 30. FIG. 9A-9F As shown, the guide locking hub 30 optionally includes two locking channels 38. However, it is contemplated that the guide locking hub 30 may include one locking channel 38 or more than two locking channels 38. The locking channel 38 may optionally be shaped as a recess or groove in the surface of the guide locking hub 30, or formed as a slotted opening, a clip, or any other feature capable of receiving and securing the guide 31 / locking sleeve 28 together with the guide locking hub 30. FIG. 9B As shown, the locking channel 38 provides an interface to secure the sheath locking sleeve 28 to the guide locking hub 30 and ensures a fixed axial position between the guide 6 and the sheath 8.

[0172] like FIG. 9B As shown, a locking channel 38 is formed on or near the distal end of the guide locking hub 30. In some embodiments, the locking channel 38 includes an opening on the distal end surface of the guide locking hub 30. The opening extends into the locking channel 38 and into an angled guide portion 40 that transitions / extends into a locking portion 42. In some embodiments, the guide portion 40 is configured to guide a guide 31 disposed on the locking sleeve 28 along the sidewall of the guide portion 40 in the axial and / or circumferential directions toward the locking portion 42 as the guide locking hub 30 and / or the sheath locking sleeve 28 rotate. In some embodiments, the locking portion 42 is configured to securely engage the guide 31, thereby fixing the axial position of the guide locking hub 30 relative to the sheath locking sleeve 28. FIG. 9BAs shown, the guide portion 40 of the locking channel 38 extends axially from the distal end of the guide locking hub 30 toward the proximal end of the guide locking hub 30 and also circumferentially around the guide locking hub 30. For example, in some embodiments, the guide portion 40 of the locking channel 38 may be described as extending spirally around / along the length of the guide locking hub 30 or extending at an angle to the distal end of the guide locking hub 30.

[0173] like FIG. 9B and FIG. 9D As shown, the locking portion 42 of the locking channel 38 extends from the end of the guide portion 40. In some embodiments, the locking portion 42 extends from the end of the guide portion 40 at an angle. FIG. 9B As provided, the angle between the centerline of the guide portion 40 and the centerline of the locking portion 42 is greater than 90 degrees. In another example, the angle between the centerline of the guide portion 40 and the centerline of the locking portion 42 is approximately 120 degrees. In the example system, the locking portion 42 extends around a portion of the circumference of the guide locking hub 30. The locking portion 42 may optionally extend substantially parallel to the distal end surface of the guide locking hub 30. In some embodiments, the locking portion 42 may optionally extend circumferentially around the guide locking hub 30 in a direction substantially perpendicular to the longitudinal axis of the guide locking hub 30 and / or the guide 6. In the example system, the length of the guide portion 40 (measured along its centerline) is greater than the length of the locking portion 42 (measured along its centerline). In another example, the length of the guide portion 40 is equal to or less than the length of the locking portion 42.

[0174] The locking portion 42 may optionally include a snap 44 for securing the guide 31 within the locking portion 42 of the locking channel 38 and forming a partial barrier for retaining the guide 31 within the locking portion 42. FIG. 9B As shown, the latch 44 includes a protrusion extending from the sidewall 74 of the locking portion 42, and its size and configuration are designed to releasably secure the guide 31 within the locking channel 38. In some embodiments, the latch 44 extends from the sidewall 42a of the locking portion 42 in a proximal direction toward the centerline of the locking portion 42, and has a height sufficient to hold the guide 31 between the latch 44 and the end of the locking portion 42.

[0175] In some embodiments, the distal end surface 72 of the guide locking hub 30 optionally includes features for biasing the guide 31 toward and / or into the locking channel 38. For example, in some embodiments, the distal end of the guide locking hub 30 may include a tapered surface angled toward the opening of the locking channel 38. For example, as... FIG. 9BAs shown, the distal end 72 of the guide locking hub 30 includes a first tapered surface 76 angled toward the leading edge of the opening toward the locking channel 38 and a second tapered surface 78 angled toward the trailing edge of the opening toward the locking channel 38. The angle between the first tapered surface 76 and the second tapered surface 78 facilitates pushing the guide 31 in the proximal direction and into the locking channel 38.

[0176] In use, the engagement between the guide 31 and the guide portion 40 of the locking channel 38 is configured such that when the sheath locking sleeve 28 rotates in a first axial direction, it biases the locking sleeve 28 toward the proximal end 70 of the guide locking hub 30 (towards the locked position) in a proximal direction. In this direction, the guide 31 advances toward the locking portion 42 of the locking channel 38 to the locked position. Alternatively, when the sheath locking sleeve 28 rotates in a second (opposite) axial direction, the engagement between the guide 31 and the locking portion 42 of the locking channel 38 is configured such that it biases the locking sleeve 28 toward the distal end of the guide locking hub 30 (towards the unlocked position) in a distal axial direction. In the second direction, the guide 31 moves away from the locking portion 42 of the locking channel 38 to the unlocked position / towards the unlocked position. For example, when the guide 31 is in the locked position and held within the locking portion 42 by the latch 44, rotation in the second direction causes the guide 31 to overcome the opposing force of the latch 44 and be biased against the latch 44. Further rotation in the second direction causes the guide 31 to move from the locked position to the unlocked position beyond the latch 44 and into / through the guide portion 40.

[0177] like FIG. 8A-9F As shown, the outer surface of the guide lock hub body 32 optionally includes gripping features and / or surfaces for use by a physician or technician when manipulating the guide lock hub 30. FIG. 9B As provided, the guide lock hub body 32 may optionally include two recessed gripping surfaces 34 located on opposite sides of the longitudinal axis of the guide lock hub 30. In some embodiments, when viewed from the side, the gripping surfaces 34 define a dog bone / barbell shaped hub body 32, i.e., a shape having a smaller diameter / width central portion and a larger diameter / width end portion. In the example system, the gripping surfaces 34 are optionally positioned along at least 40% of the length of the guide lock hub body 32. In another example, the gripping surfaces 34 are positioned along at least 50% of the length of the guide lock hub body 32.

[0178] Generally, the guide locking hub 30 can be formed of polycarbonate. In other embodiments, the guide locking hub 30 can be formed of rigid plastic or any other material suitable for providing a locking mechanism for the guide 6, including, for example, metal, composite material or other suitable material.

[0179] As described herein, the guide device / sheath assembly includes an inflatable sheath 8 extending distally from a sheath hub 20. The inflatable sheath 8 has a central lumen to guide a channel for the delivery device 10 for a medical device / implant 12 (artificial heart valve). In some embodiments, the guide device / sheath assembly does not need to include a sheath hub 20. For example, the sheath 8 may be an integral part of a component of the sheath assembly, such as a guide catheter.

[0180] As described herein, the expandable sheath 8 can have a natural, unexpanded outer diameter that will locally expand as a medical device passes through it. For example, the expandable sheath 8 can be formed of a highly elastic material, wherein vasodilation is performed by the prosthetic device passing through it.

[0181] In some embodiments, the expandable sheath 8 may include a plurality of coaxial layers extending along at least a portion of the length of the sheath 8. (References herein) FIG. 11-23 The structure of the coaxial layer is described in more detail. Examples of expandable sheaths including coaxial layers are described in, for example, U.S. Patent Application No. 16 / 378,417 entitled "Expandable Sheath" and U.S. Patent Application No. 17 / 716,882 entitled "Expandable Sheath", the disclosures of which are incorporated herein by reference.

[0182] This article describes various embodiments of the coaxial layered structure of the sheath 8. For example, refer to FIG. 11-14 The example sheath 8 shown may include multiple layers, including an inner layer 102 (also referred to as the inner layer), a second layer 104 disposed around the inner layer 102 and radially outward. In some embodiments, the sheath 8 includes a third layer 106 disposed around the second layer 104 and radially outward, and a fourth outer layer 108 disposed around the third layer 106 and radially outward. In the illustrated configuration, the inner layer 102 may define a lumen 112 of the sheath extending along a central axis 114 through which a delivery device travels into the patient's blood vessels to deliver, remove, repair, and / or replace a prosthetic device, thereby moving in a direction along the longitudinal axis of the sheath 8.

[0183] refer to FIG. 12When the sheath 8 is in its uninflated state, the various layers of the sheath (e.g., inner layer 102 and / or outer layer 108) may optionally form longitudinally extending folds or creases, such that the surface of the sheath includes a plurality of ridges 126 (also referred to herein as “folds”). The ridges 126 may be circumferentially spaced from each other by longitudinally extending valleys 128. When the sheath 8 expands beyond its natural diameter D1, the ridges 126 and valleys 128 may tend to flatten or be absorbed as the surface expands radially and the circumference of the sheath 8 increases, as further described herein. When the sheath 8 collapses back to its natural diameter, the ridges 126 and valleys 128 may reform.

[0184] In some embodiments, the inner layer 102 and / or the outer layer 108 may comprise relatively thin layers of polymer material. For example, in some embodiments, the thickness of the inner layer 102 may be 0.01 mm to 0.5 mm, 0.02 mm to 0.4 mm, or 0.03 mm to 0.25 mm. In some embodiments, the thickness of the outer layer 108 may be 0.01 mm to 0.5 mm, 0.02 mm to 0.4 mm, or 0.03 mm to 0.25 mm.

[0185] In some instances, the inner layer 102 and / or the outer layer 108 may comprise a lubricated, low-friction, and / or relatively inelastic material. In certain embodiments, the inner layer 102 and / or the outer layer 108 may comprise a polymeric material with an elastic modulus of 400 MPa or greater. Exemplary materials may include ultra-high molecular weight polyethylene (UHMWPE) (e.g., Dyneema®), high molecular weight polyethylene (HMWPE), or polyether ether ketone (PEEK). Particularly for the inner layer 102, such low-friction materials can facilitate the passage of the prosthetic device through the lumen 112. Other suitable materials for the inner layer 102 and the outer layer 108 may include polyimide, polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), ethylene tetrafluoroethylene (ETFE), nylon, polyethylene, polyamide, polyether block amide (e.g., Pebax), and / or any combination of materials described herein. In some embodiments, the sheath 8 may optionally include a lubricating liner on the inner surface of the inner layer 102. Examples of suitable lubrication liners include materials that can further reduce the coefficient of friction of the inner layer 102, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Other materials suitable for lubrication liners also include those with a coefficient of friction ideally of 0.1 or less.

[0186] Additionally, some embodiments of the sheath 8 may optionally include an external hydrophilic coating on the outer surface of the outer layer 108. Such a hydrophilic coating can facilitate insertion of the sheath 8 into a patient's blood vessel, thereby reducing potential injury. Examples of suitable hydrophilic coatings include Harmony. TMAdvanced lubricating coatings, as well as other advanced hydrophilic coatings available from SurModics, Inc., Eden Prairie, MN. DSM medical coatings (available from Koninklijke DSM NV, Heerlen, the Netherlands) and other hydrophilic coatings (e.g., PTFE, polyethylene, polyvinylidene fluoride) are also suitable for use with the sheath 8. Such hydrophilic coatings may also be included on the inner surface of the inner layer 102 to reduce friction between the sheath 8 and the delivery system, thereby facilitating use and improving safety. In some embodiments, hydrophobic coatings, such as perylene, may be used on the outer surface of the outer layer 108 or the inner surface of the inner layer 102 to reduce friction.

[0187] In some implementations, the second layer 104 may be a braided layer. FIG. 13A and FIG. 13B This example illustrates the removal of the outer layer 108 to expose the sheath 8 of the elastic third layer 106. (See reference...) FIG. 13A and FIG. 13B The second braided layer 104 may include multiple components or filaments 110 (e.g., metal or synthetic wires or fibers) woven together. The second braided layer 104 may have any desired number of filaments 110, which may be oriented and woven together along any suitable number of axes. For example, see reference... FIG. 13B The filament 110 may include a first set of filaments 110A oriented parallel to a first axis A, and a second set of filaments 110B oriented parallel to a second axis B. The first set of filaments 110A and the second set of filaments 110B may be woven together in a biaxial knit such that the filaments 110A oriented along axis A and the filaments 110B oriented along axis B form an angle θ. In some embodiments, the angle θ may be 5° to 70°, 10° to 60°, 10° to 50°, or 10° to 45°. In the example shown, the angle θ is 45°. In other embodiments, the filaments 110 may also be shaped along three axes and woven in a triaxial knit, or oriented along any number of axes and woven in any suitable knit pattern. The second layer 104 may be woven along substantially the entire length of the sheath 8. LThe filament 110 may extend, or alternatively, only a portion of the length of the sheath. In certain embodiments, the filament 110 may be a wire made of a metal (e.g., nitinol, stainless steel, etc.) or any of a variety of polymers or polymer composites (such as carbon fiber). In some embodiments, the filament 110 may be circular and may have a diameter of 0.01 mm to 0.5 mm, 0.03 mm to 0.4 mm, or 0.05 mm to 0.25 mm. In other embodiments, the filament 110 may have a flat cross-section with dimensions of 0.01 mm x 0.01 mm to 0.5 mm x 0.5 mm or 0.05 mm x 0.05 mm to 0.25 mm x 0.25 mm. In one aspect, the filament 110 with a flat cross-section may have dimensions of 0.1 mm x 0.2 mm. However, other geometries and sizes are also suitable for some embodiments. If braided wire is used, the braiding density may optionally vary along the length of the sheath 8. Some embodiments have a weave density of ten to eighty threads per inch, and may include eight, sixteen, or up to fifty-two threads in various weave patterns. In other embodiments, the second layer 104 may be cut from the tube by laser, or cut from the sheet by laser cutting, punching, perforation, etc., and then rolled into a tubular configuration. The second layer 104 may also be woven or knitted, depending on the requirements.

[0188] The third layer 106 may be a resilient layer (also referred to as a layer of elastic material). In some embodiments, the resilient third layer 106 may be configured to exert a radially inward force on the underlying layers 102, 104 in the radial direction (e.g., toward the central axis 114 of the sheath) as the sheath 8 expands beyond its natural diameter through the delivery device. In other words, the resilient third layer 106 may be configured to exert circumferential / radially inward pressure on the layers of the sheath 8 below the resilient third layer 106 (e.g., layers 102 and 104) to counteract the expansion of the sheath 8. The radially inward force is sufficient to cause the sheath 8 to radially collapse back to its unexpanded state after the delivery device has passed through the sheath 8.

[0189] In some embodiments, the elastic third layer 106 may optionally include one or more components configured as strands, strips, or elastic bands 116 spirally wound around the braided second layer 104. For example, in the illustrated aspect, the elastic third layer 106 includes two elastic bands 116A and 116B wound around the braided second layer 104 with opposite helical degrees, but the elastic third layer 106 may include any number of bands depending on desired properties. Elastic bands 116A and 116B may be made from, for example, any of a variety of natural or synthetic elastomers, including silicone rubber, natural rubber; any of a variety of thermoplastic elastomers; polyurethanes, such as polyurethane silicone copolymers, urethane, plasticized polyvinyl chloride (PVC), styrene block copolymers, polyolefin elastomers, etc. In some embodiments, the elastic third layer 106 may include an elastomer material with an elastic modulus of 200 MPa or less. In some embodiments, the elastic third layer 106 may include a material exhibiting an elongation at break of 200% or greater, or 400% or greater. The elastic third layer 106 may also take other forms, such as a tubular layer comprising an elastomeric material, a mesh, a shrinkable polymer layer, such as a heat-shrinkable tubular layer, etc. Instead of or in addition to the elastic third layer 106, the sheath 8 may also include an elastomeric or heat-shrinkable tubular layer surrounding the outer layer 108. Examples of such elastomeric layers are disclosed in U.S. Publication Nos. 2014 / 0379067, 2016 / 0296730, and 2018 / 0008407, which are incorporated herein by reference. In other embodiments, the elastic third layer 106 may also be radially outside the polymer outer layer 108.

[0190] In some embodiments, one or both of the inner layer 102 and / or the outer layer 108 may be configured to resist axial elongation of the sheath 8 when it expands. More specifically, one or both of the inner layer 102 and / or the outer layer 108 may resist the stretching of longitudinal forces caused by friction between the prosthetic device and the inner surface of the sheath 8, such that the length... L The length of the sheath 8 remains substantially constant during expansion and contraction. (See the description of the length of the sheath 8 in this text.) L The term "substantially constant" refers to the length of the sheath 8. L Increases may not exceed 1%, 5%, 10%, 15%, or 20%. Meanwhile, refer to... FIG. 13B This allows the filaments 110A and 110B of the second layer 104 to move at an angle relative to each other, such that the angle θ changes as the sheath 8 expands and contracts. This, combined with the longitudinal folds / ridges 126 in the inner layer 102 and the outer layer 108, allows the lumen 112 of the sheath 8 to expand as the prosthesis / implant 12 is advanced through it.

[0191] In some embodiments, the inner layer 102 and the outer layer 108 may be thermally bonded during the manufacturing process, such that the braided second layer 104 and the elastic third layer 106 are encapsulated between the layers 102 and the outer layer 108. More specifically, in some embodiments, the inner layer 102 and the outer layer 108 may be adhered to each other through the space between the filaments 110 of the braided second layer 104 and / or the space between the elastic bands 116. The layers 102 and the outer layer 108 may also be bonded or adhered together at the proximal and / or distal ends of the sheath 8. In some embodiments, the layers 102 and the outer layer 108 are not adhered to the filaments 110. This allows the filaments 110 to move at an angle relative to each other and relative to the layers 102 and the outer layer 108, thereby allowing the diameter of the braided second layer 104 to increase or decrease, and thus the diameter of the sheath 8 to increase or decrease. The length of the braided second layer 104 may also change when the angle θ between the filaments 110A and 110B changes. For example, as the angle θ increases, the second braided layer 104 can shorten, and as the angle θ decreases, the second braided layer 104 can stretch to the extent permitted by the area where layer 102 and outer layer 108 are joined. However, since the second braided layer 104 does not adhere to layer 102 and outer layer 108, the change in the length of the braided layer with the change in the angle θ between filaments 110A and 110B does not affect the length of the sheath 8. L Significant changes.

[0192] FIG. 14 The radial expansion of the sheath 8 is illustrated when the prosthetic device (e.g., implant 12) passes through the sheath 8 in the direction of arrow 132 (e.g., distally). As the prosthetic device / implant 12 is advanced through the sheath 8, the sheath can elastically expand to a second diameter D2 corresponding to the size or diameter of the prosthetic device / implant 12. As the prosthetic device / implant 12 is advanced through the sheath 8, the prosthetic device / implant 12 can exert a longitudinal force on the sheath 8 in the direction of movement by means of frictional contact between the prosthetic device and the inner surface of the sheath 8. However, as described herein, in some embodiments, the inner layer 102 and / or the outer layer 108 can resist axial elongation, such that the length of the sheath 8... L Keep it constant or substantially constant. This reduces or prevents the elongation of the second braided layer 104, thereby shrinking the lumen 112.

[0193] Simultaneously, the angle θ between filaments 110A and 110B can be increased as the sheath 8 expands to the second diameter D2 to accommodate the prosthetic device / implant 12. This can result in a shortening of the braided second layer 104. However, in some embodiments, because the filaments 110 do not bond or adhere to the inner layer 102 or the outer layer 108, the shortening of the braided second layer 104 with increasing angle θ does not affect the overall length of the sheath 8.L Furthermore, due to the longitudinally extending folds / ridges 126 formed in the inner layer 102 and the outer layer 108, the inner layer 102 and the outer layer 108, despite being relatively thin and relatively inelastic, can expand to a second diameter D2 without rupturing. In this way, when the prosthetic device / implant 12 is advanced through the sheath 8, the sheath 8 can elastically expand from its natural diameter D1 to a second diameter D2 greater than D1 without elongating and / or shrinking. Therefore, the force required to push the prosthetic implant 12 through the sheath 8 is significantly reduced.

[0194] Furthermore, due to the radial force applied by the elastic third layer 106, the radial expansion of the sheath 8 can be limited to a specific portion of the sheath 8 occupied by the prosthetic device. For example, see reference... FIG. 14 As the prosthetic device / implant 12 moves distally through the sheath 8, the portion of the sheath 8 immediately adjacent to the prosthetic device (e.g., the implant 12) can radially collapse back to its initial diameter D1 under the influence of the elastic third layer 106. The inner layer 102 and outer layer 108 can also bend as the circumference of the sheath 8 decreases, resulting in the reformation of the ridges 126 and valleys 128. This reduces the size of the sheath 8 required to introduce a prosthetic device of a given size. Furthermore, the temporary, localized nature of the expansion reduces trauma to the vessel into which the sheath 8 is inserted and to surrounding tissues, because only the portion of the sheath 8 occupied by the prosthetic device expands beyond the natural diameter of the sheath, and the sheath 8 collapses back to its initial diameter once the device has passed. This limits the amount of tissue that must be stretched for the introduction of the prosthetic device, and the amount of time a given portion of the vessel must dilate.

[0195] In another example of the layered sheath 208 structure, FIG. 15-23 An example is given based on another aspect. FIG. 1 Various features of the coaxial layered structure of the expandable sheath 8. Similar reference numerals are used to describe similar elements. It should be understood that this document refers to... FIG. 11-14 The described variations (e.g., materials and alternative configurations) can also be applied. FIG. 15-23 The example shown. Furthermore, this article references... FIG. 15-23 The described variant can also be applied to FIG. 11-14 The sheath described in the text.

[0196] Similar to the references in this article FIG. 11-14 Various embodiments of the sheath 8 described, FIG. 15-23 The sheath 208 comprises multiple layers. For example, FIG. 15-23 The sheath 208 shown also includes an inner layer 202 and an outer layer 204 disposed around the inner layer 202. The inner layer 202 may define a lumen 212 through which the delivery device / implant 12 travels into the patient's blood vessels for delivery, removal, repair, and / or replacement of the prosthetic device, moving in a direction along the longitudinal axis X. Similar toFIG. 11-14 The sheath 208 shown expands partially from a first resting / uninflated diameter to a second inflated diameter to accommodate the prosthetic device as it passes through the sheath 208. After the prosthetic device has passed through a specific point in the sheath 208, each successive inflated portion or segment of the sheath 208 returns at least partially to the smaller resting / uninflated diameter. In this way, the sheath 208 can be considered self-expanding because it does not require the use of a balloon, dilator, and / or occluder for inflation.

[0197] Similar to the examples described herein, the inner layer 202 and outer layer 204 may comprise any suitable materials. Suitable materials for the inner layer 202 include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), nylon, polyethylene, polyether block amides (e.g., Pebax), and / or combinations thereof. In some embodiments, the inner layer 202 may optionally comprise a lubricating, low-friction, or hydrophilic material, such as PTFE. Such a low-friction material can facilitate the passage of the prosthetic device through the lumen defined by the inner layer 202. In some instances, the inner layer 202 may have a coefficient of friction of less than about 0.1. Some examples of the sheath 208 may optionally include a lubricating liner on the inner surface of the inner layer 202. Examples of suitable lubricating liners include materials that can further reduce the coefficient of friction of the inner layer 202, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Other materials suitable for lubricating liners also include those with a coefficient of friction ideally of about 0.1 or less.

[0198] Suitable materials for the outer layer 204 include nylon, polyethylene, Pebax, HDPE, polyurethane (e.g., Tecoflex), and other medical-grade materials. In one embodiment, the outer layer 204 may comprise high-density polyethylene (HDPE) extruded as a composite material and Tecoflex (or other polyurethane material). In some embodiments, Tecoflex may be used as an adhesive between the inner layer 202 and the outer layer 204, and may be present only along a portion of the inner surface of the outer layer 204. Other suitable materials for the inner layer 202 and the outer layer 204 are also disclosed in U.S. Patent Nos. 8,690,936 and 8,790,387, which are incorporated herein by reference.

[0199] Additionally, some examples of the sheath 208 include an optional external hydrophilic coating on the outer surface of the outer layer 204. Such a hydrophilic coating can facilitate insertion of the sheath 208 into a patient's blood vessel. Examples of suitable hydrophilic coatings include Harmony. TMAdvanced lubricating coatings, as well as other advanced hydrophilic coatings available from SurModics, Inc., Eden Prairie, MN. DSM medical coatings (available from Koninklijke DSM NV, Heerlen, the Netherlands) and other hydrophilic coatings (e.g., PTFE, polyethylene, polyvinylidene fluoride) are also suitable for use with the sheath 8.

[0200] FIG. 16 The distal end of the sheath 208 is provided along FIG. 15 The partial cross-section is indicated by section line 16-16. As described herein, the sheath 208 can be inserted into a blood vessel (e.g., the femoral artery or iliac artery) through the patient's skin, such that the soft tip portion 206 at the distal end 210 of the sheath 208 is the first portion of the sheath 208 inserted into the blood vessel. FIG. 16 As best seen in some instances, the soft tip portion 206 may comprise low-density polyethylene (LDPE) and may be configured to minimize trauma or damage to the patient's blood vessels as the sheath 208 navigates through the vascular system. For example, in some embodiments, the soft tip portion 206 may be slightly tapered to facilitate passage through blood vessels. In some embodiments, the soft tip portion 206 may be secured to the distal end 210 of the sheath 208, such as by thermally bonding the soft tip portion 206 to the inner layer 202 and outer layer 204 of the sheath 208. Such a soft tip portion 206 may be configured to have a lower stiffness than other portions of the sheath 208. In some instances, the soft tip portion 206 may have a Shore hardness of about 25D to about 40D. The soft tip 206 is configured to expand radially to allow the prosthetic device to pass through the distal opening of the sheath 208. For example, in some embodiments, the soft tip portion 206 may be formed with weakened portions, such as axially extending score lines or perforation lines, which are configured to separate as the prosthesis device passes through the soft tip portion 206 and allow the soft tip portion to expand radially.

[0201] FIG. 17 A cross-sectional view of the sheath 208 taken near the distal end 210 of the sheath 208 is shown, as follows. FIG. 16 The cross-section line in Figure 17-17 is shown. FIG. 16 and FIG. 17As shown, the sheath 208 may optionally include at least one radiopaque filler or marker. In some embodiments, the radiopaque filler or marker may include a discontinuous or C-shaped band (marker 216) positioned near the distal end 210 of the sheath 208. The marker 216 may be associated with the inner layer 202 and / or the outer layer 204 of the sheath 208. For example, in some embodiments, such as FIG. 17 As shown, marker 216 can be positioned between inner layer 202 and outer layer 204. In other instances, marker 216 can be associated with the outer surface of outer layer 204. In some instances, marker 216 can be embedded or integrated within inner layer 202 and / or outer layer 204.

[0202] FIG. 18 and FIG. 19 Additional cross-sections taken at different points along the sheath 208 are shown. FIG. 18 A cross-section of a section of the sheath 208 near the proximal end 214 of the sheath 208 is shown, as follows: FIG. 15 Section line 18-18 is shown in the diagram. At this location, the sheath 208 comprises an inner layer 202, an outer layer 204, an elastic outer layer 250 / outer sheath, and a strain-relieving layer 26. At this location, near the proximal end of the sheath 208, the inner layer 202 and outer layer 204 are generally tubular. Here, the inner layer 202 and outer layer 204 can be formed without any slits or folds in the layers. In contrast, as described herein, the inner layer 202 and outer layer 204 at different locations along the sheath 208, for example, in… FIG. 15 The points indicated by the mid-section line 19-19 and / or FIG. 21 Different configurations can be found at the point indicated by the midsection line 22-22.

[0203] like FIG. 19 As shown, the inner layer 202 can be arranged to form a generally cylindrical inner cavity 212 passing through it. The inner layer 202 may include one or more folded portions 218. FIG. 19 In the illustrated embodiment, the inner layer 202 is arranged to have a folded portion 218, which can be positioned on either side of the inner layer 202. The inner layer 202 can be continuous because there are no breaks, slits, or perforations in the inner layer 202. The outer layer 204 can be arranged in an overlapping manner such that the overlapping portion 220 overlaps with at least a portion of the folded portion 218 of the inner layer 202. FIG. 19As shown, the overlapping portion 220 also overlaps with the lower portion 222 of the outer layer 204. The lower portion 222 can be positioned below the overlapping portion 220 of the outer layer 204 and the folded portion 218 of the inner layer 202. Therefore, the outer layer 204 can be discontinuous because it includes slits or cuts to form the overlapping portion 220 and the lower portion 222. In other words, the first edge 224 of the outer layer 204 is spaced apart from the second edge 225 of the outer layer 204 so as not to form a continuous layer.

[0204] like FIG. 19 As shown, the sheath 208 may optionally include a thin layer 228 of bonding or adhesive material positioned between the inner layer 202 and the outer layer 204. In some embodiments, the adhesive material 228 may include a polyurethane material, such as Tecoflex. The adhesive material 228 may be positioned on at least a portion of the inner surface of the outer layer 204 to provide adhesion between selected portions of the inner layer 202 and the outer layer 204. For example, in some embodiments, the outer layer 204 may include only a Tecoflex layer (adhesive material 228) surrounding the portion of the lumen-forming portion of the inner layer 202 facing the inner surface 230. In other words, in some embodiments, the Tecoflex layer may be positioned such that it does not contact the folded portion 218 of the inner layer 202. In other embodiments, the Tecoflex layer may be positioned in different configurations depending on the needs of a particular application. For example, as FIG. 19 As shown, the Tecoflex layer can be positioned along the entire inner surface 230 of the outer layer 204. In an alternative embodiment, the Tecoflex layer can be applied to the outer surface of the inner layer 202 instead of the inner surface of the outer layer 204. The Tecoflex layer can be applied to all or selected portions of the inner layer 202; for example, the Tecoflex layer can be formed only on the portion of the inner layer 202 facing the lumen-forming portion of the outer layer 204, and not on the folded portion 218. FIG. 19 The configuration allows the sheath 8 to expand radially when an outward radial force is applied from the inside (e.g., by passing a medical device such as an artificial heart valve through the lumen 212). When the radial force is applied, the folded portion 218 can at least partially separate, straighten, and / or unfold, and / or the overlapping portion 220 of the outer layer 204 and the lower portion 222 can slide circumferentially relative to each other, thereby allowing the diameter of the lumen 212 to increase.

[0205] In this way, the sheath 208 is configured from a static / unexpanded configuration ( FIG. 19 ) Expand to FIG. 20 The expansion configuration is shown in the figure. In the expansion configuration, as... FIG. 20As shown, an annular gap 232 can be formed between the longitudinal edge of the overlapping portion 220 and the lower portion 222 of the outer layer 204. When the sheath 208 expands at a specific location, the overlapping portion 220 of the outer layer 204 can move circumferentially relative to the lower portion 222 when the folded portion 218 of the inner layer 202 unfolds. Such movement can be facilitated by using a low-friction material such as PTFE for the inner layer 202. Furthermore, the folded portion 218 can at least partially separate and / or unfold to accommodate a medical device with a diameter larger than the diameter of the lumen 212 in its resting / unexpanded configuration. FIG. 20 As shown, in some embodiments, the folded portion of the inner layer 202 can be fully unfolded, so that the inner layer 202 forms a cylindrical tube at the location of the expanded configuration.

[0206] Similar to FIG. 14 In the example sheath 8 described herein, sheath 208 is configured to locally expand at a specific location corresponding to the position of the medical device along the length of lumen 212, and then locally contract as the medical device has passed that specific location. Thus, a protrusion may be visible as the medical device is introduced through sheath 208, extending longitudinally along the length of sheath 208, representing continuous local expansion and contraction as the device travels along the length of sheath 208. After any radially outward force is removed, each segment of sheath 208 will locally contract such that sheath 208 returns at least partially to the original rest / unexpanded diameter of lumen 212. Similar to the example sheath 8 described herein, an elastic outer layer 250 may (optionally) be provided along sheath 208 to push inner layer 202 and outer layer 204 back into the unexpanded configuration.

[0207] The layers 202 and 204 of the sheath 208 can be configured to have, for example, FIG. 19 The folded portion 218 shown is at least a portion of the length of the sheath 208. In some instances, the inner layer 202 and the outer layer 204 can be as follows: FIG. 19 The figure shows along length A ( FIG. 15 The sheath 208 is constructed such that the folded portion 218 extends from a position adjacent to the soft tip portion 206 to a position closer to the proximal end 214 of the sheath 208, adjacent to the distal end of the strain relief layer 26 and / or below the distal end of the strain relief layer. In this configuration, the sheath 208 is expandable and contractible only along a portion of its length corresponding to length A. In some embodiments, this portion of the sheath 208 corresponds to the section of the sheath 208 inserted into the narrowest segment of the patient's vascular system.

[0208] In some instances, the folded portion 218 extends from a location adjacent to the soft tip portion 206 below the strain-relieving layer 26, such as... FIG. 21As shown. In this example, the folded structure of the inner layer 202 extends from the soft tip portion 206 below the strain relief layer 26 along the tapered portion 248 of the strain relief layer 26.

[0209] FIG. 22 and FIG. 23 Provided along FIG. 21 The cross-sectional view of the sheath 208 taken at section line 22-22 of the strain relief layer 26. In this example, the folded portion 218 of the inner layer 202 extends below the strain relief layer 26. FIG. 22 A cross-section of a sheath 208 in a stationary / unexpanded configuration with an inner diameter D1 is shown. FIG. 23 A cross-section of the sheath 208 in a (partially) inflated configuration is shown, having an inner diameter D2, where D2 is greater than D1.

[0210] like FIG. 22 and FIG. 23 As shown, in some instances, the overlapping portion 220 does not overlap with the entire folded portion 218 of the inner layer 202, such that a portion of the folded portion 218 can be adjacent to / aligned with the strain relief layer 26 where it is present. In locations where the strain relief layer 26 is absent, a portion of the folded portion 218 can be seen from the outside of the sheath 208, as... FIG. 21 As shown (and / or visible through the resilient outer layer 250 described in more detail herein). In some embodiments, the sheath 208 may include a longitudinal seam 234, wherein the overlapping portion 220 terminates at the folded portion 218. In use, the sheath 208 may be positioned such that the seam 234 is behind a point on the sheath 208 that is 180 degrees to the seam 234 (e.g., at...). FIG. 21 (In the view facing downwards). For example... FIG. 21 As shown, in some embodiments, the seam 234 does not need to extend the entire length of the sheath 208 and terminates at the transition point between the portion of the sheath 208 with the folded inner layer and the portion of the sheath 208 without the folded inner layer.

[0211] In some instances, the folded portion 218 may include a weakened portion 236. In some embodiments, the weakened portion 236 includes longitudinal perforations, notches, and / or slits along at least a portion of the length of the inner layer 202. The weakened portion 236 / slit allows two adjacent ends 238, 240 of the folded portion 218 / inner layer 202 to expand / move within the sheath 208. FIG. 23 The expansion configurations shown move relative to each other. For example, in some embodiments, when a medical device is inserted through the sheath 208, the sheath partially expands, thereby causing the weakened portion 236 to separate / dissociate.

[0212] In each of the example sheaths described herein (e.g., sheath 8 and sheath 208), sheath 208 may include an elastic outer layer 250 that expands together with sheath 208. Although references... FIG. 15-23 The sheath 208 provided describes an elastic outer layer 250, but it is envisioned that the elastic outer layer 250 may also be provided with... FIG. 11-14 The sheath 8 provided herein and any other sheaths described herein. The elastic outer layer 250 can provide an inwardly pointing radial force that guides the sheath 208 toward a folded / unexpanded configuration. Similar to the strain relief layer 26, the elastic outer layer 250 can also provide hemostasis to help prevent blood loss during implantation of the prosthetic device and / or placement of the sheath 208 within a blood vessel.

[0213] The elastic outer layer 250 may be positioned around at least a portion of the strain-relieving layer 26, outer layer 204, and / or inner layer 202 (and / or outer layer 108, inner layer 102) of the sheath 208. FIG. 21-23 As shown, the outer layer 250 may surround the entire circumference of the outer layer 204 and may extend longitudinally along any portion of the length of the sheath 208, including extending longitudinally along the strain-relieving layer 26 (above and / or below). The resilient outer layer 250 extends a certain length along at least a portion of the body of the sheath 208. In some instances, the resilient outer layer 250 extends to a point adjacent to the distal end 210 of the sheath 208. In some embodiments, the resilient outer layer 250 may extend all the way to the distal end 210 of the sheath 208. In some embodiments, the resilient outer layer 250 extends over the entire length of the sheath 208.

[0214] like FIG. 17-20 , FIG. 22 and FIG. 23 As shown, the elastic outer layer 250 can be a continuous tubular layer without slits or other discontinuities. The elastic outer layer 250 extends between the strain-relieving layer 26 and the outer surface of the outer layer 204. In other embodiments, the elastic outer layer 250 extends above the outer surface of the strain-relieving layer 26 and the outer surface of the outer layer 204. In some embodiments, the elastic outer layer 250 extends above the strain-relieving layer 26 and / or between the outer layer 204 and the strain-relieving layer 26 of the sheath 208.

[0215] The elastic outer layer 250 may comprise any flexible, elastic material that expands and contracts, preferably having a high expansion ratio. Preferably, the material used may comprise a low-stiffness polymer with high elasticity, such as Pebax, polyurethane, siloxane, and / or polyisoprene. The material used for the elastic outer layer 250 may be selected such that it does not impede the expansion of the inner layer 202 and outer layer 204 of the sheath 208. The elastic outer layer 250 may have a thickness in the range of, for example, from about 0.001″ to about 0.010″. In some embodiments, the elastic outer layer 250 may have a thickness in the range of from about 0.003″ to about 0.006″. The elastic outer layer 250 may be configured to stretch and expand when the sheath 208 expands, such as... FIG. 20 As shown in the expansion configuration in the figure.

[0216] like FIG. 2 , FIG. 15 and FIG. 21 As shown, sheath 8 and sheath 208 include a strain-relieving layer 26. Although reference... FIG. 15-23 The sheath 208 provided describes a strain relief layer 26, but it is envisioned that the strain relief layer 26 may also include... FIG. 11-14 The sheath 8 provided herein and any other sheath described herein.

[0217] The strain relief layer 26 / tube is disposed near the proximal end of the sheath 208 and extends along / above the outer surface of the sheath 208. In some embodiments, the strain relief layer 26 is disposed above the outer layer 204 (and / or the outer layer 208) of the sheath 208. The strain relief layer 26 forms a smooth transition between the sheath hub 20 and the sheath 208 and facilitates the fit between the sheath 208 and the sheath hub 20.

[0218] Additionally, and as will be described in more detail herein, the strain relief layer 26 provides a region of higher stiffness or rigidity that restricts the expansion of the underlying sheath layer. This helps ensure hemostasis between the portion of the sheath 8, 208 inside the patient and the sheath hub (outside the patient). The increased stiffness and / or rigidity along the strain relief layer 26 prevents blood from flowing between the various layers of the sheath 208 outside the patient during the procedure, which helps withstand blood pressure that would otherwise cause the sheath 208 to “swell” due to body fluid / blood. Furthermore, in some embodiments, the size and configuration of the strain relief layer 26 may be designed to form a seal with the patient’s artery upon insertion, thereby substantially preventing blood flow between the strain relief layer 26 and the vessel wall. For example, although the strain relief layer 26 does not extend all the way to the distal end 210 of the sheath 208, it may extend distally along the sheath 208 sufficiently such that when the sheath 208 is inserted into the patient’s vessel, a portion of the strain relief layer 26 extends through the arterial incision site and seals against the arterial incision site.

[0219] As described herein, a strain relief layer 26 is disposed over the outer layer 204 (and / or outer layer 108) of the sheath 208. In some embodiments, the strain relief layer 26 may be bonded to the outer layer 204 to prevent the strain relief layer 26 from sliding over the outer layer 204 and from “aggregating” in response to frictional forces exerted by surrounding tissues during insertion of the sheath 208 into the patient’s vascular system. For example, the strain relief layer 26 may be bonded to the proximal and / or distal ends of the outer layer 204. In some embodiments, at the proximal and distal ends, the strain relief layer 26 may be bonded to the outer layer 204 around its entire circumference. In some embodiments, at the distal end of the sheath 208, the strain relief layer 26 may alternatively be bonded to the inner layer of the sheath 208. For example, the strain relief layer 26 may be bonded to the distal end surface of the inner layer 202.

[0220] FIG. 18 , FIG. 22 and FIG. 23 A cross-sectional view of the sheath 208 along the strain relief layer 26 is shown. FIG. 18 A cross-section of a section of the sheath 208 near the proximal end 214 of the sheath 208 is shown, as follows: FIG. 15 Line 18-18 is shown in the diagram. Similarly, FIG. 22 and FIG. 23 Cross-sectional sections of various example sheaths are shown near the proximal end 214 of the sheath 208 and closer to the distal end of the strain-relieving layer 26, such as FIG. 21 The cross-section line 22-22 is shown in the figure. FIG. 15-23 As shown in each figure, the sheath 208 at this location may include an inner layer (lining) 202, an outer layer 204, an adhesive material layer 228, an optional elastic outer layer 250, and a strain relief layer 26.

[0221] The strain-relieving layer 26 extends circumferentially around at least a portion of the inner layer 202 and the outer layer 204. The strain-relieving layer 26 extends from the proximal end 214 of the sheath 208 in a direction toward the distal end 210 of the sheath 208. FIG. 21 (and FIG. 15 As shown, the strain-relieving layer 26 extends for a length L along at least a portion of the body of the sheath 208. In some examples, the strain-relieving layer 26 extends to a point adjacent to the distal end 210. In other examples, the strain-relieving layer 26 extends all the way to the distal end 210 of the sheath 208. In some examples, the longitudinal length L of the strain-relieving layer 26 can range from about 10 cm to the entire length of the sheath 208.

[0222] In some embodiments, the strain-relieving layer 26 extends to / adjacent to the proximal end 214 of the sheath 208 and provides a compression fit over the distal end of the sheath hub 20, thereby engaging the sheath 208 to the sheath hub 20. Alternatively or additionally, the strain-relieving layer 26 may be secured between the sheath hub 20 and the sheath hub cap 22 (or other fastening means for engaging the proximal end of the sheath 208 to the sheath hub 20), such as... FIG. 5A and FIG. 5B As shown. In some instances, the strain relief layer 26 does not extend all the way to the proximal end 214 of the sheath 208.

[0223] It should be understood that, as shown herein, the strain relief layer 26 may have a similar composition and properties to the inner layer 202 and outer layer 204 disclosed herein. Various compositions are disclosed, for example, in application number PCT / US2021 / 301275 entitled “Expandable sheath for introducing an endovascular delivery device into a body,” the disclosure of which is incorporated herein by reference.

[0224] In some embodiments, the strain-relieving layer 26 may comprise a lubricating, low-friction, and / or relatively inelastic material. Preferably, the material used may comprise a high-hardness polymer with low elasticity. In some instances, the strain-relieving layer 26 is composed of the same and / or similar material as the inner layer 202 and / or the outer layer 204 (including the inner layer 102 and / or the outer layer 108). For example, as described herein with respect to the inner layer 102 and the outer layer 108, exemplary materials may include polyurethane (e.g., high-density polyethylene), ultra-high molecular weight polyethylene (UHMWPE) (e.g., Dyneema®), high molecular weight polyethylene (HMWPE), or polyether ether ketone (PEEK). Other suitable materials for the strain-relieving layer 26 may include polyimide, polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), ethylene tetrafluoroethylene (ETFE), nylon, polyethylene, polyamide, polyether block amide (e.g., Pebax), and / or combinations of any of the above materials. The material used for the strain relief layer 26 can be selected such that its material properties help prevent expansion of the layer beneath the sheath 208.

[0225] The strain relief layer 26 may have a thickness in the range of, for example, from about 0.001″ to about 0.010″. In some embodiments, the strain relief layer 26 may have a thickness of from about 0.003″ to about 0.006″. The wall thickness is measured radially between the inner surface and the outer surface of the strain relief layer 26.

[0226] In an alternative embodiment, the material composition and / or wall thickness may vary along the length of the strain-relieving layer 26. For example, the strain-relieving layer 26 may be provided with one or more segments, wherein the composition and / or thickness vary with each segment. In an example embodiment, the hardness rating of the composition varies along the length of the strain-relieving layer 26, such that segments near the proximal end comprise a harder material or combination of materials, while segments near the distal end comprise a softer material or combination of materials. Similarly, the wall thickness of the strain-relieving layer 26 in the segments near the proximal end may be thicker / greater than the wall thickness of the elastic outer layer 250 near the distal end.

[0227] like FIG. 15 , FIG. 21 and FIG. 24 As shown, the strain relief layer 26 has a proximal end and a distal end, as well as a central lumen extending longitudinally therethrough. The strain relief layer 26 includes a generally tubular proximal portion 242 adjacent to the proximal end of the strain relief layer 26 and a generally tubular distal portion 246 adjacent to the distal end of the strain relief layer 26. In some embodiments, the strain relief layer 26 includes a truncated conical tapered portion 248 extending between the proximal and distal portions of the strain relief layer 26, such that the diameter of the strain relief layer 26 at the proximal portion 242 is larger than the diameter of the strain relief layer 26 at the distal portion 246. The tapered portion 248 and the flared proximal portion 242 facilitate a smooth transition when the medical device / delivery system passes between a larger diameter sheath hub 20 and a smaller diameter sheath 208. As described herein, in some embodiments, the tapered portion 248 and / or the flared portion 242 provide a radially inward compressive force against the medical device / delivery system as it is advanced through the sheath hub 20 and into the sheath 208, thereby helping to compress the medical device / delivery system to a smaller diameter. Therefore, the thrust required to advance the medical device / delivery system into the sheath 208 is reduced, thereby reducing the likelihood of damage to the sheath 208 and / or the medical device / delivery system.

[0228] As described herein, the strain relief layer 26 is made of a harder material than the other layers of the sheath 208, such that the strain relief layer 26 inhibits expansion along the portion of the strain relief layer 26 / the portion of the sheath disposed below it. Because radial expansion along the strain relief layer 26 is restricted, a higher thrust is required to propel the medical device (implant 12) through the central lumen of the sheath 208 corresponding to the portion of the strain relief layer 26. In some instances, the highest thrust through the sheath 208 is experienced near the ends of the strain relief layer 26 (e.g., the proximal and distal ends).

[0229] In some embodiments, the thickness and / or composition of the strain relief layer 26 can be adjusted to improve the performance of the strain relief layer 26 and reduce thrust. While the steps and benefits of a pre-expanded sheath are described with reference to sheath 208, it is contemplated that corresponding steps and benefits may also be provided with respect to sheath 8 and any other sheath described herein. As described herein, a pre-expanded sheath 208 or a portion thereof may help reduce the thrust required to insert a medical device / delivery system through the central lumen of sheath 208.

[0230] The pre-expanded sheath 208 will release and / or loosen any bonds or adhesions that occur during the manufacturing process between the sheath 208 layers, such as bonds between the inner layers 102, 202 and the outer layers 108, 204, bonds between adjacent ridges 126, bonds between the folded portion 218 and the outer layer 204, bonds between the inner layers 102, 202 and the outer layers 108, 204 and the strain relief layer 26, bonds along the strain relief layer 26 or at the distal tip, or bonds that resist expansion. In some embodiments, the pre-expanded strain relief layer 26 may also cause the weakened portion 236 of the folded portion 218 of the inner layer 202 to break or separate, thereby separating adjacent ends 238, 240 of the folded portion 218 as described herein. FIG. 23 As shown in the diagram. With layer 208 able to move freely relative to the other layer, the medical device / delivery system is pushed through the lumen of sheath 208 with much less force.

[0231] In some cases, the sheath 208 is pre-dilated by passing a relatively large dilator (e.g., a 22-French dilator) through it. Pre-dilation may include passing the dilator through the strain relief layer 26 and / or the distal tip of the sheath 208. The pre-dilation step may be performed during manufacturing and / or during sheath 208 preparation, before the sheath 208 is inserted into the patient, and / or after the sheath 208 is at least partially inserted into the patient. However, in some cases, pre-dilation of the sheath 208 may result in a seam or edge with a partial opening between the now-released layers of the sheath 208, which may introduce the possibility of vascular complications, such as difficulty in inserting, moving, and / or withdrawing the pre-dilated sheath 208 or the possibility of vascular injury, and may also be aesthetically unacceptable to the physician.

[0232] The apparatus, systems, and methods described herein provide systems and methods for pre-expanding the sheath 208 while also preventing longitudinal seams or opening edges of the expanded sheath 208 layers (e.g., referenced herein) FIG. 21The described seam 234 expands axially after pre-expansion or prevents further radial opening during, for example, sterilization or aging of the sheath 208. The system described herein allows the sheath 208 to expand during manufacturing without requiring expansion by medical personnel during sheath preparation, thereby reducing preparation time and eliminating the unnecessary possibility of error and / or accidental damage to the sheath 208.

[0233] FIG. 24 An example system 300 including a sheath 208 and an expander 350 is shown. (Although reference...) FIG. 15-23 The sheath 208 provided describes the corresponding method of system 300 and pre-expanded sheath, but it is contemplated that system 300 and the corresponding method may also be consistent with the reference. FIG. 11-14 Use with the provided sheath 8 or any other expandable sheath described herein.

[0234] At least a portion of the sheath 208 (e.g., inner layers 102, 202 and / or strain-relieving layer 26) is configured to extend from the lumen 212 into an unexpanded configuration having a first diameter (e.g., FIG. 18-19 The expansion configuration, which partially expands into the lumen 212 to have a larger second diameter (e.g., FIG. 20 The expansion of the sheath 208 is guided by an outwardly directed radial force applied to the lumen 212 by the expansion element 365 of the expander 350 (and / or medical device) received within the sheath 208. The sheath 208 then partially contracts back to its unexpanded configuration as the expander 350 (and / or medical device) passes through the lumen 212. As will be described in more detail herein, a restraint member 385 restricts the expansion of the sheath 208 (e.g., the inner layer 202 and / or strain-relieving layer 26) in the vicinity of the restraint member 385. By restricting the expansion / unfolding of the sheath 208, the use of the restraint member 385 prevents the longitudinal seam 234 or the opening edge between adjacent layers of the expanded sheath 208 from axially expanding and / or further radially opening after pre-expansion.

[0235] FIG. 24 (and FIG. 25 The representative sheath shown corresponds to the expandable sheath configuration described herein, for example... FIG. 11-14 and / or FIG. 15-23 The layered configuration is shown. The sheath 208 includes a continuous inner layer (e.g., inner layer 202) defining a central lumen extending therethrough and a corresponding outer layer (e.g., outer layer 204). Reference will be made to the following description. FIG. 15-23 The layered structure of the sheath 208 can be used to describe the sheath 208. However, it is conceivable that the sheath 208 can be described using... FIG. 11-14The sheath 208 has a layered sheath structure. For example, in some embodiments, the sheath 208 includes a continuous inner layer 202 defining a lumen 212 therethrough. The inner layer 202 includes a proximal portion 320 and a body portion 330, as well as a folded portion 218 extending along the length of the inner layer 202. In some embodiments, the sheath 208 includes an outer layer (e.g., an outer layer 204) disposed above the inner layer 202 and below or above the tubular strain relief layer 26. The sheath 208 includes a tubular strain relief layer 26 disposed above the inner layer 202 at a proximal end of the sheath 208 and extending along at least a portion of the length of the sheath 208. As described herein, the strain relief layer 26 provides a region of higher stiffness or rigidity that restricts the expansion of the underlying sheath layer. The strain relief layer 26 is disposed at the proximal end of the sheath 208 and extends along at least a portion of the length of the sheath 208. Similar to the inner layer 202 and the outer layer 204, at least a portion of the strain relief layer 26 is configured to partially expand from an unexpanded configuration of a first diameter to an expanded configuration of a larger second diameter due to the outward radial force exerted on the lumen 212 of the inner layer 202 by the expander 350 (or medical device) against the inner layer 202, and then at least partially contract back to the unexpanded configuration as the expander 350 (or medical device) passes through the lumen 212.

[0236] like FIG. 24 As shown, the sheath 208 includes a constraint member 385 disposed above the sheath 208 for restricting the expansion / deployment of adjacent / below portions of the sheath 208. In some embodiments, when the sheath moves from an unexpanded configuration to an expanded configuration, the constraint member 385 restricts the expansion / deployment of the folded portion 218 of the inner layer 202 and / or movement between the inner layer 202 and the outer layer 204. Therefore, this prevents the longitudinal seam 234 from forming / opening between the overlapping portion 220 of the outer layer 202 and the folded portion 218 of the inner layer 202. FIG. 21 This also helps prevent the openings / gap formed between adjacent layers of the folded portion 218 from expanding axially (e.g., proximal or distal along the length of the sheath 8). It also helps prevent any openings / gap formed between adjacent layers of the folded portion 218 from opening further radially after pre-expansion.

[0237] In some implementations, such as FIG. 24As shown, the restraining member 385 is positioned above the distal end 342 of the strain-relieving layer 26. Therefore, the restraining member 385 restricts the expansion of the lower portion and / or adjacent portion of at least one of the inner layer 202 and the strain-relieving layer 26. For example, in some embodiments, the restraining member 385 is disposed across the length of the sheath 208 at a position corresponding to the distal end 342 of the strain-relieving layer 26, and extends along a length (part A) of the strain-relieving layer 26 extending from the distal end 342 toward the proximal end of the strain-relieving layer 26. FIG. 24 As provided in some embodiments, the restraint member 385 extends along a second length (part B) of the sheath 208 extending from the distal end 342 of the strain relief layer 26 toward the distal end of the sheath 208.

[0238] The restraint member 385 may be made of a material with lower elasticity than the layer below the sheath 208 and / or strain-relieving layer 26, such that the restraint member 385 restricts and / or prevents radial expansion of the sheath 208 / strain-relieving layer 26. In some embodiments, the restraint member 385 is made of a band, shrink tube, elastic tube, packaging feature, or other structure or material disposed above the sheath 208 to restrict radial expansion. In some embodiments, the restraint member 385 is coupled to the sheath 208. For example, in some embodiments, the restraint member 385 is coupled to the outer surface of the inner layer 202 and / or strain-relieving layer 26. In some embodiments, the restraint member 385 is releasably coupled to the sheath 208. For example, in some embodiments, the inner surface of the restraint member 385 may include an adhesive (e.g., a temporary / releasable adhesive and / or a resealable adhesive) for coupling the restraint member 385 to the sheath 208. In some embodiments, the restraint member 385 includes a shrink tube coupled to at least one of the inner layer 202 or strain-relieving layer 26 via a shrinkage process (e.g., a shrinkage heating process). In some embodiments, the restraint member 385 includes a release feature 386 for removing the restraint member 385 from the sheath 208. For example, the release feature 386 can be used to partially or completely remove the restraint member 385 from the inner layer 202 and / or the strain relief layer 26. In some embodiments, the release feature 386 may include at least one of a weakened portion (e.g., a perforation, a notch, a slit, etc.) or a tab and / or a line integral with the restraint member 385, which, when at least one of these items is activated, at least partially separate the restraint member 385 from or along the sheath 208.

[0239] In some implementations, such as FIG. 25 As shown, release feature 386 is incorporated into a package whose size and configuration are designed to receive sheath 208. FIG. 25A sheath system 300 is shown included in its corresponding packaging pallet 400. The pallet 400 includes notches / recesses sized and configured to securely receive components of the sheath system 300. Removing the sheath 208 from the pallet 400 when the release feature 386 is engaged in the pallet 400 also removes the restraint member 385 from the inner layer 202 and / or strain relief layer 26. For example, in some embodiments, a portion of the restraint member 385 and / or the release feature 386 (e.g., a pull tab or thread) is fixedly coupled to the pallet 400 such that when the sheath 208 is removed from the pallet 400, the restraint member 385 is at least partially separated from and / or separated along the sheath 208. In some embodiments, at least a portion of the restraint member 385 may remain coupled to the pallet 400 when separated from the sheath 208. In some embodiments, the restraint member 385 may be separated from both the sheath 208 and the pallet 400 when separated from the sheath 208. In some embodiments, when the sheath 208 is removed from the tray 400, the release feature 386 is activated and the restraint member 385 separates from and / or along the sheath 208. For example, in some embodiments, the release feature 386 includes a weakened portion along the restraint member 385. When the sheath 208 is removed from the tray 400, separation or tearing along the weakened portion is triggered, and the restraint member 385 is removed from or separates from the sheath 208.

[0240] System 300 includes an expander 350 whose size and configuration are designed to be received within a central lumen 212 of the inner layer 202. For example... FIG. 24 As shown, the dilator 350 includes an elongated dilator shaft 360, above which an expansion element 365 is disposed. As described herein, in response to an outwardly directed radial force applied to the central lumen 212 by the expansion element 365 of the dilator 350 (and / or medical device), the sheath 208 partially expands from an unexpanded configuration to an expanded configuration.

[0241] In some embodiments, the expander shaft 360 includes a body portion 363 adjacent to a proximal end 364 of the expander shaft 360 and a tapered portion 366 extending from a distal end 362 of the expander shaft 360 toward the body portion 363. In some embodiments, the length of the expander shaft 360 received within the hub opening 376 is adjustable to change the length 380 of the expander 350, i.e., the length by which the expander 350 extends from the expander hub 370. The proximal end 364 of the expander shaft 360 is coupled to the expander hub 370 at the hub opening 376. In some embodiments, the hub opening 376 extends from the distal end 372 of the hub toward the proximal end 374 of the hub, and the expander shaft 360 is fixedly coupled within the hub opening 376. In use, the expander shaft 360 is inserted from the proximal end 306 of the sheath hub 20, passes through the central lumen 308 of the sheath hub 20, and enters the central lumen 212 of the sheath 208. In some embodiments, the expander hub 370 is coupled to the proximal end 306 of the sheath hub 20.

[0242] In some embodiments, the expansion element 365 is disposed on the main body portion 363 of the expander 350. In some embodiments, such as FIG. 24 As shown, the expansion element 365 is defined by the main body portion 363 of the expander shaft 360. In other embodiments, the expansion element 365 includes a protrusion extending radially from the outer surface of the expander shaft 360. For example, the expansion element 365 may include a protrusion of regular or irregular shape that extends from the outer surface of the expander shaft 360 and surrounds all or part of the circumference of the expander 350.

[0243] In some embodiments, the diameter of the expansion element 365 is larger than the unexpanded diameter of the sheath 208, such that movement of the expansion element 365 through the lumen 212 of the sheath 208 causes the sheath 208 to expand radially to a diameter larger than its unexpanded diameter. In some embodiments, the diameter of the expansion element 365 is 22F. For example, in some embodiments, the expansion element 365 has a diameter in the range of 12F to 24F. In another example, the expansion element 365 has a diameter in the range of 14F to 24F. In some examples, the expansion element 365 has a diameter in the range of 14F to 22F. The diameter of the expansion element 365 can be selected based on the unexpanded diameter of the sheath 208 and / or the diameter of the delivery system / medical device and the corresponding desired pre-expansion amount of the sheath 208.

[0244] This document describes a method for producing and / or manufacturing a pre-expandable, inflatable sheath for delivery of a medical device. The method includes providing a radially inflatable sheath according to any of the examples described herein. (Although references...) FIG. 15-23 The sheath 208 provided in the document describes a method for producing a pre-expanded sheath, but it is envisioned that this method can also be used in conjunction with the reference.FIG. 11-14 The provided sheath 8 or any other expandable sheath described herein may be used together. In some embodiments, the sheath 208 includes a continuous inner layer 202 defining a lumen 212 of the sheath 8. The inner layer 202 includes a proximal portion 320 and a body portion 330. In some embodiments, the inner layer 202 includes a folded portion 218 extending along the length of the sheath 208 corresponding to the proximal portion 320 and / or the body portion 330. In some embodiments, the sheath 208 includes a tubular strain-relieving layer 26 disposed above the proximal portion 320 of the inner layer 202.

[0245] The method includes positioning a restraining member 385 over a portion of the sheath 208. In some embodiments, the restraining member 385 is positioned at least over the distal end 342 of the strain-relieving layer 26. The restraining member 385 provides an inwardly pointing radial force that restricts the expansion of adjacent portions of the inner layer 202 and / or the strain-relieving layer 26, thereby preventing the longitudinal seam 234 and / or other opening edges formed between adjacent layers of the expanded sheath 208 from axially expanding or further radially opening after pre-expansion. For example, when the sheath 208 moves from an unexpanded configuration to an expanded configuration during the advancement of the expander 350, the inwardly pointing radial force provided by the restraining member 385 restricts the unfolding of the folded portion 218 of the inner layer 202 near the restraining member 385.

[0246] By positioning the restraint member 385 above the distal end 342 of the strain relief layer 26, the restraint member 385 is positioned above a portion of the sheath 208, including the beginning of the exposed portion of the seam 234. For example... FIG. 21 As shown, the proximal portion of joint 234 extends below strain relief layer 26, and the distal portion of joint 234 extends along sheath 208 beyond strain relief layer 26. In some embodiments, such as FIG. 24 As shown, the constraint member 385 is disposed above the sheath 208 at the distal end 342 of the strain relief layer 26, and also extends distally over the first length (part A) of the sheath 208 toward the proximal end of the strain relief layer 26 and also extends distally along the second length (part B) toward the distal end 210 of the sheath 208.

[0247] In some embodiments, the restraint member 385 is releasably coupled to the sheath 208. For example, the restraint member 385 can be releasably coupled to the sheath 208 using a temporary adhesive applied to the inner surface of the restraint member 385 or a corresponding portion of the sheath 208 (e.g., a corresponding portion of the outer surface of the inner layer 202 and / or the strain relief layer 26). In some embodiments, the restraint member 385 includes tape applied to the outer surface of the sheath 208. In some instances, the restraint member 385 includes a shrink tube disposed above the sheath 208 and a shrinkage process, such as a shrinkage heating process, is applied.

[0248] The method also includes introducing an expander 350 into the proximal end 214 of the central lumen 212 of the sheath 208 and advancing the expander 350 through the sheath 208 for the desired length. In some embodiments, the expander 350 is advanced through the proximal portion 320 of the inner layer 202 corresponding to the strain-relieving layer 26. Thus, the expansion element 365 applies an outwardly pointing radial force to the central lumen 212 of the sheath 208, and causes the inner layer 202 and the strain-relieving layer 26 near the expansion element 365 to partially expand from an unexpanded configuration to an expanded configuration. As the expander 350 moves through the central lumen 212, the inwardly pointing radial force applied by the restraining member 385 restricts the expansion and / or unfolding of the lower portion of the sheath 208; that is, the restraining member 385 restricts the expansion / unfolding of the inner layer 202, the outer layer 204, and / or the strain-relieving layer 26 to prevent unnecessary expansion of the longitudinal seam 234 or other openings.

[0249] In some embodiments, the expander 350 is advanced through the proximal portion 320 of the inner layer 202 such that the expansion element 365 of the expander 350 is aligned with the distal end 342 of the strain relief layer 26, causing the distal end 342 of the strain relief layer 26 to expand. For example, the expander 350 may be advanced within the lumen 212 of the sheath 208 until the proximal end 368 of the tapered portion 366 of the expander 350 and / or the distal end of the body portion 363 of the expander shaft 360 is aligned with the distal end 342 of the strain relief layer 26.

[0250] In some embodiments, the expander 350 is advanced through the proximal portion 320 of the inner layer 202 such that the expansion element 365 of the expander 350 is located outside the distal end 342 of the strain-relieving layer 26. Therefore, the distal end 342 of the strain-relieving layer 26 and a portion of the body portion 330 of the inner layer 202 are at least partially expanded. For example, the expander 350 may be advanced within the lumen 212 of the sheath 208 until the proximal end 368 of the tapered portion 366 of the expander shaft 360 and / or the distal end of the body portion 363 are located outside the distal end 342 of the strain-relieving layer 26. In some instances, the expansion element 365 is used to expand / inflate the length of the body portion 330 of the sheath, which extends 10 mm to 15 mm beyond the distal end 342 of the strain-relieving layer 26. In this example, expanding the length of the main body portion 330 of the sheath 208 beyond the distal end 342 of the strain-relieving layer 26 causes the corresponding length of the folded portion 218 to be released from the bond between the folded layers of the inner layer 202 and thus at least partially unfolded. A restraining member 385 is provided above this portion of the sheath 208 to limit any undesirable separation from the unfolding and any other openings along the seam 234 or between adjacent layers of the expanded sheath 208.

[0251] In some embodiments, the method further includes heating the sheath 208. In some embodiments, heating the sheath 208 in a partially expanded configuration heat-sets the size (e.g., width and / or length) of the seam 234 or opening edge between adjacent layers of the expanded sheath 208. For example, the heating step can be provided by a heat sterilization process and / or heat-setting process applied to the sheath 208 in an expanded / expanded configuration. However, during the heating step, the sheath 208 is not heated to a temperature or duration sufficient to bond the layers of the folded portion 218. In some embodiments, the heating step includes heating the sheath 208 at a temperature and duration corresponding to the sterilization process. For example, in some embodiments, the sheath 208 is heated at a temperature of 60°C. In some embodiments, the sheath 208 is heated for a duration exceeding 12 hours. For example, the sheath 208 is heated at 60°C for 24 hours. In some instances, the sheath 208 is heated at 60°C for 26 hours.

[0252] In some embodiments, the expander 350 is coupled to the sheath hub 20 and / or the expander hub 370 prior to the heating step. The expander 350 can be advanced through the proximal portion 320 of the sheath 208 until the expander hub 370 abuts against the sheath hub 20. In some embodiments, the expander hub 370 is then coupled to the sheath hub 20, thereby securing the position of the expander 350 within the lumen 212 of the sheath 208. In some instances, the expander hub 370 is releasably coupled to the sheath hub 20 via a mechanical connection, including, for example, a press fit, interference fit, snap fit, pin, thread, bayonet fastener, clip, and / or locking key. With the expander hub 370 fixed relative to the sheath hub 20, the user can be assured that no further advancement (or retraction) of the expansion element 365 will occur during the heating steps, including preparation and cooling.

[0253] In some embodiments, the method further includes removing the expander 350 from the lumen 212 of the sheath 208 after the heating step is completed. That is, in some embodiments, the expander 350 remains within the sheath 208 during the heating step. In other embodiments, the expander 350 is removed from the lumen 212 of the sheath 208 before the heating step.

[0254] In some embodiments, the method further includes removing the restraint member 385 from the sheath 208. For example, the restraint member 385 may be removed from the inner layer 202 and / or the strain relief layer 26 after the heating step is completed and before the medical procedure. In some instances, the restraint member 385 is removed from the sheath 208 before the heating step. In some embodiments, the restraint member 385 is removed before the expander 350 is removed from the sheath 208. In some embodiments, the restraint member 385 is removed after the expander 350 is removed from the sheath 208.

[0255] In some embodiments, the restraint member 385 includes a release feature 386 as described herein. When the release feature 386 includes a weakened portion (e.g., a perforation, score line, slit, etc.), the restraint member 385 can be removed from the sheath 208 by applying an outward force to the restraint member 385 in a direction away from the sheath 208. The outward force causes the restraint member 385 to separate along the weakened portion. When the release feature 386 includes a pull tab or pull cord integral with the restraint member 385, the restraint member 385 is removed from the sheath 208 when the pull tab / pull cord is activated and pulled away from the sheath 208. In some instances, the restraint member 385 is removed from the sheath 208 by cutting or tearing it. For example, when the restraint member 385 includes a heat shrink tube, the restraint member 385 can be removed from the sheath 208 by cutting the heat shrink tube from the sheath 208.

[0256] In some embodiments, as described herein, the restraint member 385 is incorporated into the packaging pallet 400 such that removing the sheath 208 from the pallet 400 at least partially removes the restraint member 385 from the sheath 208, including at least partially removing the restraint member 385 from the inner layer 202 and / or the strain relief layer 26.

[0257] With restraint member 385 removed, sheath 208 can be used to deliver a medical device to the surgical site within a patient's blood vessel. (See reference...) FIG. 15-23 The sheath 208 provided in the document describes a method for delivering a medical device using a pre-expanded sheath, but it is envisioned that this method can also be used with the reference FIG. 11-14 Use with the provided sheath 8 or any other expandable sheath described herein.

[0258] This document describes a method for delivering a medical device using a pre-dilated sheath 208. The method involves at least partially inserting the pre-dilated sheath 208 into a patient's blood vessel, such that the distal end of the sheath 208 is positioned near the treatment site. The sheath 208 can be pre-dilated using the dilator 350 and method described herein. Because the sheath 208 is pre-dilated, the medical device can be introduced more easily and with less thrust into the central lumen 212 of the (pre-dilated) sheath 208 and into the patient's blood vessel.

[0259] The method also includes advancing the medical device through the portion of the sheath 208 corresponding to the strain-relieving layer 26, applying an outwardly pointing radial force to the central lumen (e.g., the inner layer) of the sheath 208, and ensuring that the sheath 208 (including the inner layer and / or the strain-relieving layer 26) near the medical device remains in a never-expanded configuration. FIG. 17-19 and FIG. 22 Local expansion to expansion configuration ( FIG. 20 and FIG. 23 In some instances, the medical device radially contracts or compresses as it passes from the proximal portion 242 through the strain-relieving layer 20, through the tapering portion 248, and into the smaller diameter distal portion 246. As the medical device passes through the corresponding portion of the lumen of the sheath 208, the sheath 208 and the strain-relieving layer 26 locally contract toward the unexpanded configuration.

[0260] The method also includes advancing the medical device beyond the distal end 342 of the strain relief layer 26 and into the lumen of the main body portion of the sheath 208 (beyond the strain relief layer 26) and ultimately beyond the distal end opening in the sheath 208 to reach the treatment site. As the medical device is advanced through the sheath 208 beyond the strain relief layer 26 and through the distal opening, the sheath 208 remains in a non-expanded configuration near the medical device in response to an outwardly pointing radial force applied to the inner layer / central lumen of the sheath 208. FIG. 11-13Aand FIG. 17-19 Local expansion to expansion configuration ( FIG. 14 , FIG. 20 Because the sheath 208 has been pre-expanded as described herein, the unfolding of other openings along the seam 234 or between adjacent layers of the expanded sheath 208 and any undesirable separation are restricted.

[0261] In some embodiments, at least one of the inner and / or outer layers includes at least one folded portion. For example, in some embodiments, the sheath includes... FIG. 11-14 The ridges 126 and valleys 128 of the fourth (outer) layer 108 of the sheath 8 shown, and FIG. 15-23 The inner layer 202 of the sheath 208 shown has a folded portion 218. Locally expanding the lumen of the sheath causes the length of the folded portion to unfold at least partially. Similarly, partially contracting the sheath back to its unexpanded configuration causes the length of the folded portion to be pushed back into the folded configuration.

[0262] In some embodiments, the outer layer 204 is a discontinuous outer layer and includes an overlapping portion (e.g., overlapping portion 220) and a lower portion (e.g., lower portion 222). When the sheath 208 is in an uninflated configuration, the overlapping portion 220 overlaps with the lower portion 222, wherein a folded portion 218 of the inner layer is disposed between the overlapping portion 220 and the lower portion 222. FIG. 17 , FIG. 19 , FIG. 22 , FIG. 23 When the sheath 208 partially expands to the expanded configuration / towards the expanded configuration, the length of the overlapping portion 220 shifts circumferentially relative to the unfolded lower portion 222. (e.g.) FIG. 20 As shown, when the sheath 208 is fully expanded, the inner layer 202 extends into the gap 232 formed between the longitudinal edge of the overlapping portion 220 and the lower portion 222 of the outer layer 204.

[0263] When the medical device passes through the lumen of the sheath 208, the sheath 208 at least partially contracts back to its unexpanded configuration. FIG. 11-13A and FIG. 17-19 ).

[0264] The method also includes advancing the medical device through the distal tip 9 / distal opening of the sheath 208 and delivering the medical device to the treatment site. The position of the medical device can be moved or adjusted until the medical device is properly positioned within the patient. Once the medical device has been delivered to the treatment site, any delivery system / component coupled to the medical device is then removed from the medical device and withdrawn from the lumen of the sheath 208. The sheath 208 is removed from the opening in the patient and blood vessel, and the skin is closed.

[0265] The medical device described herein may include a prosthetic device mounted on a delivery device in a radially coiled state, and the action of advancing the prosthetic device through the lumen of sheath 208 includes advancing the delivery device and the prosthetic device through the lumen of sheath 208 and into the patient's vascular system. In some instances, the prosthetic device includes a prosthetic heart valve, and the method further includes implanting the prosthetic heart valve at a treatment site within the patient's body. As described herein, when the prosthetic heart valve is advanced through sheath 208, the prosthetic heart valve is mounted on the balloon catheter of the delivery device.

[0266] Given the many possible implementations to which the principles of the disclosed content can be applied, it should be recognized that the illustrated embodiments are merely preferred examples of this disclosure and should not be considered as limiting the scope of this disclosure. Rather, the scope of this disclosure is defined by the following claims. Therefore, we claim protection for all content within the scope and spirit of these claims as part of our disclosure.

[0267] Exemplary Aspects Given the many possible aspects to which the principles of the disclosed content can be applied, it should be recognized that the aspects shown are merely preferred examples of this disclosure and should not be considered as limiting the scope of this disclosure. Rather, the scope of this disclosure is defined by the following claims. Therefore, we claim protection for all content within the scope and spirit of these claims as part of our disclosure.

[0268] Example 1. A method of manufacturing a pre-expandable inflatable sheath for delivery of a medical device, the method comprising: providing a radially inflatable sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a body portion, and having a folded portion extending along the length of the inner layer; a tubular strain relief layer disposed above the proximal portion of the inner layer; wherein at least a portion of the sheath is configured to partially expand from an unexpanded configuration of the lumen having a first diameter to an expanded configuration of the lumen having a larger second diameter, and then at least partially partially contract back to the unexpanded configuration; providing A constraint member positioned above the distal end of the strain-relieving layer, the constraint member restricting the expansion of adjacent portions including at least one of the inner layer and the strain-relieving layer; an expander introduced into the proximal end of the lumen of the sheath, the expander including an expansion element disposed thereon; advancing the expander through the proximal portion of the inner layer such that the expansion element disposed on the expander applies an outwardly radial force to the lumen and causes the inner layer near the expansion element to partially expand from an unexpanded configuration to an expanded configuration, wherein the constraint member restricts the expansion of the sheath near the constraint member; and heating the sheath.

[0269] Example 2. The method according to any embodiment herein, particularly Example 1, wherein when the sheath moves from the uninflated configuration to the inflated configuration during the advance of the expander through the proximal portion of the inner layer, the constraint member restricts the unfolding of the folded portion of the inner layer near the constraint member.

[0270] Example 3. The method according to any embodiment herein, particularly Examples 1 to 2, wherein the constraint member is disposed across the length of the sheath at a position corresponding to the distal end of the strain relief layer, and extends along the length of the strain relief layer from the distal end toward the proximal end of the strain relief layer, and extends along a second length of the sheath from the distal end of the strain relief layer toward the distal end of the sheath.

[0271] Example 4. The method according to any embodiment herein, particularly Examples 1 to 3, wherein providing the constraint member above the sheath includes connecting the constraint member to at least one of the inner layer or the strain relief layer.

[0272] Example 5. The method according to any embodiment herein, particularly Example 4, wherein the inner surface of the constraint member includes an adhesive for attaching the constraint member to the sheath.

[0273] Example 6. The method according to any embodiment herein, particularly Example 4, wherein the constraint member includes a shrink tube, and connecting the constraint member to at least one of the inner layer or the strain relief layer includes providing a shrinkage process to the constraint member.

[0274] Example 7. The method according to any embodiment herein, particularly Examples 1 to 6, further comprising: removing the constraint member from the inner layer and the strain relief layer.

[0275] Example 8. The method according to any embodiment herein, particularly Example 7, wherein the constraint member is removed after the heating step.

[0276] Example 9. The method according to any embodiment herein, particularly Example 7, wherein the constraint member is removed prior to the heating step.

[0277] Example 10. The method according to any embodiment herein, particularly Example 9, wherein a release feature is incorporated into a package whose size and configuration are designed to receive the sheath, wherein providing a radially expandable sheath includes removing the sheath from the package, wherein removing the sheath from the package removes the restraint member from the inner layer and the strain relief layer.

[0278] Example 11. The method according to any embodiment herein, particularly Examples 1 to 10, wherein advancing the expander through the proximal portion of the inner layer comprises advancing the expansion element of the expander toward the distal end of the strain relief layer, such that the distal end of the strain relief layer expands.

[0279] Example 12. The method according to any embodiment herein, particularly Examples 1 to 11, wherein advancing the expander through the proximal portion of the inner layer includes advancing the expansion element of the expander beyond the distal end of the strain relief layer, such that the distal end of the strain relief layer and a portion of the main body portion of the inner layer expand.

[0280] Example 13. The method according to any embodiment herein, particularly Example 12, wherein the portion of the main body is expanded beyond the strain relief layer such that the corresponding length of the folded portion is at least partially unfolded.

[0281] Example 14. The method according to any embodiment herein, particularly Examples 1 to 13, further comprising: removing the expander from the lumen of the sheath after the heating step is completed.

[0282] Example 15. The method according to any of the embodiments herein, particularly Examples 1 to 14, further comprising: removing the dilator from the lumen of the sheath prior to the heating step.

[0283] Example 16. According to any of the embodiments herein, particularly Examples 1 to 15, at least a portion of the strain relief layer is configured to locally expand from an unexpanded configuration of a first diameter to an expanded configuration of a larger second diameter, and then at least partially shrink back to the unexpanded configuration.

[0284] Example 17. The method according to any embodiment herein, particularly Example 16, wherein at least a portion of the strain relief layer is configured to partially expand from the unexpanded configuration to the expanded configuration in response to an outwardly pointing radial force applied to the lumen by the expander, and then at least partially contract back to the unexpanded configuration as the expander moves within the lumen, wherein at least a portion of the sheath is configured to partially expand from the unexpanded configuration to the expanded configuration in response to an outwardly pointing radial force applied to the lumen of the inner layer by the expander, and then at least partially contract back to the unexpanded configuration as the expander moves within the lumen.

[0285] Example 18. According to any embodiment herein, particularly Examples 1 to 17, the sheath further includes: an outer layer disposed above the inner layer, wherein the outer layer is discontinuous and includes an overlapping portion and a lower portion, and the overlapping portion overlaps with the lower portion, wherein at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the lower portion, wherein the strain relief layer extends at least partially above the outer layer.

[0286] Example 19. The method according to any embodiment herein, particularly Example 18, wherein, in the unexpanded configuration, the folded portion extends circumferentially above the outer surface of the inner and / or outer layers, wherein, in the expanded configuration, partial expansion causes the length of the folded portion to at least partially unfold, and wherein, in the expanded configuration, partial expansion of the sheath causes the length of the overlapping portion to move circumferentially relative to the lower portion.

[0287] Example 20. The method according to any embodiment herein, particularly Example 19, wherein, in the expansion configuration, the partial expansion of the sheath forms a gap between the longitudinally extending edges of the outer layer, wherein at least a portion of the expanded portion extends into the gap, and wherein the restraining member restricts the expansion of the sheath and the width of the gap in the vicinity of the restraining member.

[0288] Example 21. The method according to any embodiment herein, particularly Examples 1 to 20, wherein the sheath further includes an elastic outer cover that extends at least partially over the sheath, wherein the outer cover locally expands and contracts as the medical device is advanced through the lumen, wherein the elastic outer cover applies a radially inward force on the sheath.

[0289] Example 22. The method according to any embodiment herein, particularly Examples 1 to 20, wherein the sheath further includes a sheath hub fixedly coupled to the proximal end of the sheath, the sheath hub including a central lumen extending through the lumen of the sheath and coaxial with the lumen of the sheath, wherein the size and configuration of the expander shaft are designed to be received within the central lumen of the sheath hub, wherein the expander includes an expander hub coupled to the proximal end of the expander shaft, wherein the method further includes: advancing the expander through the proximal portion until the expander hub abuts the sheath hub; and coupling the expander hub to the sheath hub before heating the sheath.

[0290] Example 23. The method according to any embodiment herein, particularly Examples 1 to 21, wherein heating the sheath comprises heating the sheath at a temperature and duration corresponding to the sterilization process, wherein, during the heating, the sheath is not heated to a temperature or duration sufficient to bond the layers of the folded portion.

[0291] Example 24. The method according to any of the embodiments herein, particularly Examples 1 to 23, wherein heating the sheath comprises heating the sheath at a temperature of 60°C.

[0292] Example 25. The method according to any of the embodiments herein, particularly Examples 1 to 24, wherein heating the sheath includes heating the sheath for a duration longer than 12 hours.

[0293] Example 26. A sheath system comprising: a radially expandable sheath, the radially expandable sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a main portion and a folded portion extending along the length of the inner layer; a tubular strain relief layer disposed above the proximal portion of the inner layer; a restraining member positioned above a distal end of the strain relief layer, the restraining member restricting the expansion of adjacent portions of at least one of the inner layer and the strain relief layer; and an expander, the expander... The size and configuration are designed to be received within the lumen of the inner layer, the expander including an elongated expander shaft and an expansion element disposed thereon; wherein at least a portion of the sheath is configured to partially expand from an unexpanded configuration of the lumen having a first diameter to an expanded configuration of the lumen having a larger second diameter in response to an outwardly directed radial force applied to the lumen by the expansion element of the expander, and then at least partially contract back to the unexpanded configuration as the expander passes through the lumen, wherein the constraint member restricts the expansion of the sheath in the vicinity of the constraint member.

[0294] Example 27. A sheath system according to any embodiment herein, particularly Example 26, wherein when the sheath moves from the uninflated configuration to the inflated configuration, the constraint member restricts the unfolding of the folded portion of the inner layer near the constraint member.

[0295] Example 28. A sheath system according to any embodiment herein, particularly Examples 26 to 27, wherein the restraining member is disposed across the length of the sheath at a position corresponding to the distal end of the strain relief layer, and extends along the length of the strain relief layer from the distal end toward the proximal end of the strain relief layer, and extends along a second length of the sheath from the distal end of the strain relief layer toward the distal end of the sheath.

[0296] Example 29. A sheath system according to any embodiment herein, particularly Examples 26 to 28, wherein the restraining member comprises at least one of a strap, a shrink tube, an elastic tube, or a packaging feature.

[0297] Example 30. A sheath system according to any embodiment herein, particularly Examples 26 to 29, wherein the constraint member is coupled to the sheath.

[0298] Example 31. A sheath system according to any embodiment herein, particularly Example 30, wherein the inner surface of the restraint member includes an adhesive for attaching the restraint member to the sheath.

[0299] Example 32. A sheath system according to any embodiment herein, particularly Example 30, wherein the restraining member includes a shrink tube, wherein the restraining member is coupled to at least one of the inner layer or the strain relief layer by a shrink process.

[0300] Example 33. A sheath system according to any embodiment herein, particularly Examples 26 to 32, wherein the restraining member includes a release feature for removing the restraining member from the sheath.

[0301] Example 34. A sheath system according to any embodiment herein, particularly Example 33, wherein the release feature includes at least one of a weakened portion or a pull tab and / or a line integral with the restraining member.

[0302] Example 35. A sheath system according to any embodiment herein, particularly Examples 33 to 34, wherein the release feature is incorporated into a package whose size and configuration are designed to receive the sheath, wherein removing the sheath from the package removes the restraint member from the inner layer and the strain relief layer.

[0303] Example 36. A sheath system according to any embodiment herein, particularly Examples 26 to 35, wherein the expander shaft includes a body portion adjacent to a proximal end of the expander shaft and a tapered portion extending from a distal end of the expander shaft toward the body portion, wherein the expansion element is disposed on the body portion.

[0304] Example 37. A sheath system according to any embodiment herein, particularly Examples 26 to 36, wherein the expansion element is defined by the main body portion of the expander shaft.

[0305] Example 38. A sheath system according to any embodiment herein, particularly Examples 26 to 37, wherein the expansion element includes a protrusion extending from the outer surface of the expander shaft.

[0306] Example 39. A sheath system according to any embodiment herein, particularly Examples 26 to 38, wherein the diameter of the expansion element is 22F.

[0307] Example 40. A sheath system according to any embodiment herein, particularly Examples 26 to 39, wherein at least a portion of the strain relief layer is configured to locally expand from an unexpanded configuration of a first diameter to an expanded configuration of a larger second diameter, and then at least partially shrink back to the unexpanded configuration.

[0308] Example 41. A sheath system according to any embodiment herein, particularly Example 40, wherein at least a portion of the strain relief layer is configured to partially expand from the unexpanded configuration to the expanded configuration in response to an outwardly directed radial force applied to the lumen by the expander, and then at least partially contract back to the unexpanded configuration as the expander 350 moves within the lumen.

[0309] Example 42. A sheath system according to any embodiment herein, particularly Examples 26 to 41, wherein the strain relief layer comprises: a proximal portion adjacent to a proximal end of the strain relief layer; a distal portion adjacent to a distal end of the strain relief layer; and a tapered portion extending between the distal portion and the proximal portion, wherein the diameter of the proximal portion is larger than the diameter of the distal portion.

[0310] Example 43. A sheath system according to any embodiment herein, particularly Examples 26 to 42, wherein the strain relief layer comprises a material that is harder and / or less elastic than the inner layer and restricts the expansion of the inner layer.

[0311] Example 44. A sheath system according to any embodiment herein, particularly Examples 26 to 43, wherein the strain relief layer comprises a material with a higher hardness than the inner layer, such that the strain relief layer restricts the expansion of the sheath.

[0312] Example 45. A sheath system according to any of the embodiments herein, particularly Examples 26 to 44, wherein the strain relief layer comprises polyurethane.

[0313] Example 46. A sheath system according to any embodiment herein, particularly Examples 26 to 45, wherein the length of the strain relief layer remains constant as the strain relief layer moves from the unexpanded configuration to the expanded configuration.

[0314] Example 47. A sheath system according to any embodiment herein, particularly Examples 26 to 46, wherein the sheath further comprises: an outer layer disposed above the inner layer; wherein the strain relief layer comprises a material that is harder and / or less elastic than the inner layer and the outer layer, and restricts the expansion of at least one of the inner layer or the outer layer, wherein the strain relief layer comprises a material that is harder than the inner layer and / or the outer layer, such that the strain relief layer restricts the expansion of at least one of the inner layer or the outer layer.

[0315] Example 48. A sheath system according to any embodiment herein, particularly Examples 26 to 46, wherein the sheath further comprises: an outer layer disposed above the inner layer, wherein the outer layer is discontinuous and includes an overlapping portion and a lower portion, and the overlapping portion overlaps with the lower portion, wherein at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the lower portion, wherein the strain relief layer extends at least partially above the outer layer.

[0316] Example 49. A sheath system according to any embodiment herein, particularly Example 48, wherein, in the uninflated configuration, the folded portion extends circumferentially above the outer surface of the inner and / or outer layers.

[0317] Example 50. A sheath system according to any embodiment herein, particularly Examples 48 to 49, wherein, in the expansion configuration, partial expansion causes the length of the folded portion to unfold at least partially, thereby forming the unfolded portion of the inner layer, wherein, in the expansion configuration, the partial expansion of the sheath causes the length of the overlapping portion to move circumferentially relative to the lower portion.

[0318] Example 51. A sheath system according to any embodiment herein, particularly Example 50, wherein, in the expansion configuration, a partial expansion of the sheath forms a gap between the longitudinally extending edges of the outer layer, wherein at least a portion of the expanded portion extends into the gap, and wherein the restraining member limits the expansion of the sheath and the width of the gap near the restraining member.

[0319] Example 52. A sheath system according to any embodiment herein, particularly Examples 26 to 51, wherein the total length of the strain relief layer and / or sheath does not change when the sheath and / or strain relief layer moves between the unexpanded configuration and the expanded configuration.

[0320] Example 53. A sheath system according to any embodiment herein, particularly Examples 26 to 52, wherein the lumen of the inner layer is cylindrical in both the unexpanded and expanded configurations.

[0321] Example 54. A sheath system according to any of the embodiments herein, particularly Examples 26 to 53, wherein the inner layer comprises PTFE and the outer layer comprises HDPE and / or Tecoflex.

[0322] Example 55. A sheath system according to any of the embodiments herein, particularly Examples 47 to 57, wherein the inner layer and the outer layer are joined together.

[0323] Example 56. A sheath system according to any embodiment herein, particularly Examples 47 to 55, wherein the inner layer and the outer layer are thermally bonded together.

[0324] Example 57. A sheath system according to any of the embodiments herein, particularly Examples 47 to 56, wherein the inner layer and the outer layer are bonded together by an adhesive.

[0325] Example 58. A sheath system according to any embodiment herein, particularly Examples 47 to 57, wherein the strain relief layer is bonded to the outer layer and / or the inner layer.

[0326] Example 59. A sheath system according to any embodiment herein, particularly Examples 47 to 58, wherein the strain relief layer is thermally bonded and / or adhesively bonded to the outer layer and / or the inner layer.

[0327] Example 60. A sheath system according to any of the embodiments herein, particularly Examples 47 to 59, wherein the inner layer comprises woven fabric and / or braided filaments.

[0328] Example 61. A sheath system according to any of the embodiments herein, particularly Examples 47 to 60, wherein the inner layer comprises yarn filaments of PTFE, PET, PEEK and / or nylon.

[0329] Example 62. A sheath system according to any of the embodiments herein, particularly Examples 47 to 61, wherein the outer layer comprises polyurethane.

[0330] Example 63. A sheath system according to any embodiment herein, particularly Examples 26 to 62, the sheath system further comprising a resilient outer cover extending at least partially over the sheath, wherein the outer cover partially expands and contracts as the expander is advanced through the lumen, wherein the resilient outer cover applies a radially inward force on the sheath, wherein the resilient outer cover comprises PEBAX, polyurethane, siloxane, or polyisoprene, or combinations thereof.

[0331] Example 64. A sheath system according to any embodiment herein, particularly Examples 26 to 63, wherein the sheath further includes a sheath hub fixedly coupled to the proximal end of the sheath, the sheath hub including a central lumen extending through the lumen of the sheath and coaxial with the lumen of the sheath, wherein the size and configuration of the expander shaft are designed to be received within the central lumen of the sheath hub, wherein the expander includes an expander hub coupled to the proximal end of the expander shaft, wherein the expander hub is configured to be coupled to the sheath hub.

[0332] Example 65. A sheath system according to any embodiment herein, particularly Example 64, wherein the sheath hub includes one or more seals for forming a seal around the outer surface of a delivery device movable through the central lumen of the sheath hub.

[0333] Example 66. A sheath system kit comprising: a radially expandable sheath including: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a body portion and a folded portion extending along the length of the inner layer; a tubular strain relief layer disposed above the proximal portion of the inner layer; a restraining member positioned above a distal end of the strain relief layer, the restraining member restricting expansion of adjacent portions of at least one of the inner layer and the strain relief layer; an expander sized and configured to be received within the lumen of the inner layer, the expander including an elongated shaft and an expansion element disposed thereon; and a tray. The tray is sized and configured to receive the sheath and the expander, the tray including a release mechanism coupled to the restraining member, wherein, when the sheath is removed from the tray, the release mechanism retains the restraining member, thereby removing it from the sheath; wherein at least a portion of the sheath is configured to partially expand from an unexpanded configuration of the lumen having a first diameter to an expanded configuration of the lumen having a larger second diameter in response to an outwardly directed radial force applied to the lumen by the expansion element of the expander, and then at least partially partially contract back to the unexpanded configuration as the expander passes through the lumen, wherein the restraining member restricts the expansion of the sheath in the vicinity of the restraining member.

[0334] Example 67. A method of delivering a medical device through a sheath, the method comprising: providing a radially expandable sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a body portion and a folded portion extending along the length of the inner layer; a tubular strain relief layer disposed above the proximal portion of the inner layer; and a restraining member positioned above a distal end of the strain relief layer, the restraining member restricting expansion of adjacent portions of at least one of the inner layer and the strain relief layer; removing an expander received from the lumen of the inner layer, wherein the restraining member restricts the expansion of the sheath due to an outwardly directed radial force applied by the expander; removing the restraining member from the sheath; introducing a medical device into the proximal end of a central lumen of the sheath; and placing the medical device into the proximal end of the sheath. The medical device is advanced through the proximal portion of the inner layer, causing the inner layer and the strain-relieving layer near the medical device to locally expand from an unexpanded configuration to an expanded configuration, and causing the strain-relieving layer to locally contract toward the unexpanded configuration as the medical device passes through the corresponding portion of the sheath lumen; the medical device is advanced beyond the distal end of the strain-relieving layer; the medical device is advanced through the main body portion of the lumen of the sheath, causing the main body portion of the sheath to locally expand from the unexpanded configuration to the expanded configuration at a location near the medical device in response to the outwardly pointing radial force of the medical device applied to the inner layer, and causing the sheath to at least partially contract back to the unexpanded configuration as the medical device passes through the lumen; and the medical device is advanced beyond the distal opening in the sheath.

[0335] Example 68. The method according to any embodiment herein, particularly Example 67, wherein at least a portion of the sheath is configured to partially expand from an unexpanded configuration of the lumen having a first diameter to an expanded configuration of the lumen having a larger second diameter in response to an outwardly directed radial force applied to the lumen by the expansion element of the expander, and then at least partially contract back to the unexpanded configuration as the expander passes through the lumen.

[0336] Example 69. A method of inserting a medical device into a patient's blood vessel, the method comprising: providing a radially expandable sheath, the sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a body portion and a folded portion extending along the length of the inner layer; a tubular strain relief layer disposed above the proximal portion of the inner layer; and a restraining member positioned above a distal end of the strain relief layer, the restraining member restricting expansion of adjacent portions of at least one of the inner layer and the strain relief layer; removing an expander received from the lumen of the inner layer, wherein the restraining member restricts the expansion of the sheath due to an outwardly directed radial force applied by the expander; removing the restraining member from the sheath; inserting the sheath at least partially into the patient's blood vessel; introducing a medical device into the proximal end of the central lumen of the sheath; advancing the medical device through the... The medical device applies an outward radial force to the central lumen of the proximal portion of the inner layer, causing the strain-relieving layer near the medical device to locally expand from an unexpanded configuration to an expanded configuration, and causing the strain-relieving layer to locally contract toward the unexpanded configuration as the medical device passes through the corresponding portion of the sheath lumen; advances the medical device beyond the distal end of the strain-relieving layer; advances the medical device through the main portion of the sheath lumen, causing the main portion of the sheath to locally expand from an unexpanded configuration to an expanded configuration at a location near the medical device in response to the outward radial force applied to the inner layer, and at least partially contracts the sheath back to the unexpanded configuration as the medical device passes through the lumen; and advances the medical device beyond the distal opening in the sheath to reach the treatment site within the blood vessel.

[0337] Example 70. The method according to any embodiment herein, particularly Example 69, wherein the expander expands the distal end of the strain relief layer.

[0338] Example 71. The method according to any embodiment herein, particularly Examples 69 to 70, wherein the inner layer includes at least one folded portion, wherein partially expanding the lumen of the sheath causes the length of the folded portion to unfold at least partially.

[0339] Example 72. The method according to any embodiment herein, particularly Examples 69 to 71, wherein the sheath further comprises: an outer layer disposed above the inner layer, wherein the outer layer is discontinuous and includes an overlapping portion and a lower portion, wherein when the sheath is in the uninflated configuration, the overlapping portion overlaps the lower portion, wherein the folded portion of the inner layer is disposed between the overlapping portion and the lower portion, wherein the strain relief layer extends at least partially above the outer layer, and wherein the medical device is a prosthetic device mounted on a delivery device in a radially curled state.

[0340] Example 73. The method according to any embodiment herein, particularly Example 72, wherein advancing the prosthetic device through the lumen of the sheath comprises advancing the delivery device and the prosthetic device through the lumen of the sheath and into the patient's vascular system.

[0341] Example 74. The method according to any embodiment herein, particularly Example 73, wherein the prosthetic device includes a prosthetic heart valve, and the method further includes implanting the prosthetic heart valve into the treatment site in the patient.

[0342] Example 75. The method according to any of the embodiments herein, particularly Examples 73 to 74, wherein the prosthetic heart valve is mounted on the balloon catheter of the delivery device as the prosthetic heart valve is advanced through the sheath.

[0343] Example 76. The method according to any of the embodiments herein, particularly Examples 69 to 75, wherein the sheath is inserted into the patient's femoral artery.

Claims

1. A method of manufacturing a pre-dilated inflatable sheath for delivering a medical device, the method comprising: providing a radially expandable sheath, the radially expandable sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer comprising a proximal portion and a body portion, and having a folded portion extending along a length of the inner layer; a tubular strain relief layer disposed over the proximal portion of the inner layer; wherein at least a portion of the sheath is configured to be locally expanded from an unexpanded configuration in which the lumen has a first diameter to an expanded configuration in which the lumen has a second, greater diameter, and then at least partially locally contracted back to the unexpanded configuration; providing a constraining member positioned over a distal end of the strain relief layer, the constraining member limiting expansion of adjacent portions comprising at least one of the inner layer and strain relief layer; introducing an expander into a proximal end of the lumen of the sheath, the expander comprising an expansion element disposed thereon; advancing the expander through the proximal portion of the inner layer such that the expansion element disposed on the expander exerts an outwardly directed radial force on the lumen and locally expands the inner layer proximate the expansion element from an unexpanded configuration to an expanded configuration, wherein the constraining member limits expansion of the sheath proximate the constraining member; and heating the sheath.

2. The method of claim 1, wherein the constraining member limits unfolding of the folded portion of the inner layer proximate the constraining member as the sheath moves from the unexpanded configuration to the expanded configuration during the advancing of the expander through the proximal portion of the inner layer.

3. The method of claim 1, wherein the constraining member is disposed across a length of the sheath at a location corresponding to the distal end of the strain relief layer, and extends along a length of the strain relief layer from the distal end toward a proximal end of the strain relief layer, and along a second length of the sheath from the distal end of the strain relief layer toward a distal end of the sheath.

4. The method of claim 1, wherein providing the constraining member over the sheath comprises coupling the constraining member to at least one of the inner layer or the strain relief layer.

5. The method of claim 4, wherein the constraining member comprises at least one of an adhesive or a shrink tube, wherein when the constraining member comprises an adhesive, an inner surface of the constraining member comprises the adhesive for coupling the constraining member to the sheath, wherein, when the constraining member comprises the shrink tube, coupling the constraining member to at least one of the inner layer or the strain relief layer comprises providing a shrink process to the constraining member.

6. The method of claim 1, further comprising: removing the constraining member from the inner layer and the strain relief layer, wherein a release feature is incorporated into a package sized and configured to receive the sheath, wherein providing the radially expandable sheath includes removing the sheath from the package, wherein removing the sheath from the package removes the constraining member from the inner layer and the strain relief layer.

7. The method of claim 1, wherein advancing the dilator through the proximal portion of the inner layer includes advancing the expansion element of the dilator toward the distal end of the strain relief layer such that the distal end of the strain relief layer expands.

8. The method of claim 1, wherein advancing the dilator through the proximal portion of the inner layer includes advancing the expansion element of the dilator beyond the distal end of the strain relief layer such that the distal end of the strain relief layer and a portion of the main portion of the inner layer expand, wherein expanding the portion of the main portion beyond the strain relief layer causes a corresponding length of the folded portion to at least partially unfold.

9. The method of claim 1, wherein the sheath further comprises: an outer layer disposed over the inner layer, wherein the outer layer is discontinuous and includes an overlapping portion and an underlying portion, and the overlapping portion overlaps the underlying portion, wherein at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlying portion, wherein the strain relief layer extends at least partially over the outer layer, wherein, in the unexpanded configuration, the folded portion extends circumferentially over an outer surface of the inner and / or outer layer, wherein, in the expanded configuration, the local expansion is such that the length of the folded portion is at least partially unfolds , wherein, in the expanded configuration, the local expansion of the sheath causes a length of the overlapping portion to move circumferentially relative to the underlying portion and form a gap between longitudinally extending edges of the outer layer, wherein at least a portion of the unfolded portion extends into the gap, wherein the limiting member limits expansion of the sheath and a width of the gap adjacent the limiting member.

10. The method of claim 1, wherein heating the sheath includes heating the sheath at a temperature and for a duration corresponding to a sterilization process, wherein during the heating, the sheath is not heated to a temperature or for a duration sufficient to bond the layers of the folded portion.

11. A sheath system, the sheath system comprising: a radially expandable sheath, the radially expandable sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a main portion and a folded portion extending along a length of the inner layer; a tubular strain relief layer disposed over the proximal portion of the inner layer; and a constraining member positioned over a distal end of the strain relief layer, the constraining member limiting expansion of adjacent portions of at least one of the inner layer and strain relief layer; and a dilator sized and configured to be received within the lumen of the inner layer, the dilator including an elongate dilator shaft and an expansion element disposed thereon; a radially expandable sheath, the radially expandable sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer including a proximal portion and a main portion and a folded portion extending along a length of the inner layer; a tubular strain relief layer disposed over the proximal portion of the inner layer; and a constraining member positioned over a distal end of the strain relief layer, the constraining member limiting expansion of adjacent portions of at least one of the inner layer and strain relief layer; and a dilator sized and configured to be received within the lumen of the inner layer, the dilator including an elongate dilator shaft and an expansion element disposed thereon; wherein at least a portion of the sheath is configured to locally expand from an unexpanded configuration having a first diameter of the lumen to an expanded configuration having a second, greater diameter of the lumen in response to an outwardly directed radial force exerted on the lumen by the expansion element of the dilator, and then at least partially locally contract back to the unexpanded configuration as the dilator is moved through the lumen, wherein the constraining member limits expansion of the sheath proximate the constraining member.

12. The system of claim 11, wherein the constraining member is coupled to the sheath and limits unfolding of the folded portion of the inner layer proximate the constraining member as the sheath moves from the unexpanded configuration to the expanded configuration.

13. The system of claim 11, wherein the constraining member includes a release feature comprising at least one of a weakened portion or a pull tab and / or a string integral to the constraining member for removing the constraining member from the sheath, wherein the release feature is incorporated into a package sized and configured to receive the sheath, and wherein removal of the sheath from the package removes the constraining member from the inner layer and the strain relief layer.

14. The system of claim 11, wherein the dilator shaft includes a body portion adjacent a proximal end of the dilator shaft, and a tapered portion extending from a distal end of the dilator shaft toward the body portion, wherein the expansion element is disposed on the body portion and includes a protrusion extending from an outer surface of the dilator shaft.

15. The system of claim 11, wherein at least a portion of the strain relief layer is configured to locally expand from an unexpanded configuration having a first diameter to an expanded configuration having a second, greater diameter, and then at least partially locally contract back to the unexpanded configuration, wherein at least a portion of the strain relief layer is configured to locally expand from the unexpanded configuration to the expanded configuration in response to an outwardly directed radial force exerted on the lumen by the dilator, and then at least partially locally contract back to the unexpanded configuration as the dilator is moved within the lumen.

16. The system of claim 11, wherein the sheath further comprises: an outer layer disposed over the inner layer and integral to the inner layer; wherein the strain relief layer comprises a material that is stiffer and / or less elastic than the inner layer and the outer layer, and limits expansion of at least one of the inner layer or outer layer, wherein the strain relief layer comprises a material that is stiffer than the inner layer and / or the outer layer, such that the strain relief layer limits expansion of at least one of the inner layer or outer layer.

17. The system of claim 11, wherein the sheath further comprises: an outer layer disposed over the inner layer, wherein the outer layer is discontinuous and comprises an overlapping portion and an underlying portion, and the overlapping portion overlaps the underlying portion, wherein at least a portion of the folded portion of the inner layer is positioned between the overlapping portion and the underlying portion, wherein the strain relief layer extends at least partially over the outer layer.

18. The system of claim 17, wherein, In the inflated configuration, the local inflation causes the length of the folded portion to at least partially unfold, thereby forming an unfolded portion of the inner layer, wherein, in the inflated configuration, the local inflation of the sheath causes the length of the overlapping portion to move circumferentially relative to the underlying portion and form a gap between longitudinally extending edges of the outer layer, wherein at least a portion of the unfolded portion extends into the gap, wherein the restriction member limits the inflation of the sheath and the width of the gap adjacent to the restriction member.

19. The system of claim 11, wherein the total length of the strain relief layer and / or sheath does not change when the sheath and / or strain relief layer moves between the uninflated and inflated configurations.

20. A sheath system kit, the sheath system kit comprising: a radially inflatable sheath, the radially inflatable sheath comprising: a continuous inner layer defining a lumen therethrough, the inner layer comprising a proximal portion and a body portion and a folded portion extending along a length of the inner layer; a tubular strain relief layer disposed over the proximal portion of the inner layer; a restriction member positioned over a distal end of the strain relief layer, the restriction member limiting inflation of adjacent portions of at least one of the inner layer and strain relief layer; a dilator sized and configured to be received within the lumen of the inner layer, the dilator comprising an elongate shaft and an inflation element disposed thereon; and a tray sized and configured to receive the sheath and the dilator, the tray comprising a release mechanism coupled to the restriction member, wherein upon removal of the sheath from the tray, the release mechanism retains the restriction member, thereby removing it from the sheath; wherein at least a portion of the sheath is configured to locally inflate from an uninflated configuration in which the lumen has a first diameter to an inflated configuration in which the lumen has a second, greater diameter in response to an outwardly directed radial force exerted on the lumen by the inflation element of the dilator, and then at least partially locally deflate back to the uninflated configuration as the dilator is passed through the lumen, wherein the restriction member limits the inflation of the sheath adjacent to the restriction member.

21. The sheath system kit of claim 20, wherein the restriction member comprises a ring.

22. The sheath system kit of claim 20, wherein the restriction member comprises a sleeve.

23. The sheath system kit of claim 20, wherein the restriction member comprises a wire.

24. The sheath system kit of claim 20, wherein the restriction member comprises a band.

25. The sheath system kit of claim 20, wherein the restriction member comprises a clamp.

26. The sheath system kit of claim 20, wherein the restriction member comprises a clip.

27. The sheath system kit of claim 20, wherein the restriction member comprises a pin.

28. The sheath system kit of claim 20, wherein the restriction member comprises a ring and a sleeve.

29. The sheath system kit of claim 20, wherein the restriction member comprises a ring and a wire.

30. The sheath system kit of claim 20, wherein the restriction member comprises a ring and a band.

31. The sheath system kit of claim 20, wherein the restriction member comprises a ring and a clamp.

32. The sheath system kit of claim 20, wherein the restriction member comprises a ring and a clip.

33. The sheath system kit of claim 20, wherein the restriction member comprises a ring and a pin.

34. The sheath system kit of claim 20, wherein the restriction member comprises a sleeve and a wire.

35. The sheath system kit of claim 20, wherein the restriction member comprises a sleeve and a band.

36. The sheath system kit of claim 20, wherein the restriction member comprises a sleeve and a clamp.

37. The sheath system kit of claim 20, wherein the restriction member comprises a sleeve and a clip.

38. The sheath system kit of claim 20, wherein the restriction member comprises a sleeve and a pin.

39. The sheath system kit of claim 20, wherein the restriction member comprises a wire and a band.

40. The sheath system kit of claim 20, wherein the restriction member comprises a wire and a clamp.

41. The sheath system kit of claim 20, wherein the restriction member comprises a wire and a clip.

42. The sheath system kit of claim 20, wherein the restriction member comprises a wire and a pin.

43. The sheath system kit of claim 20, wherein the restriction member comprises a band and a clamp.

44. The sheath system kit of claim 20, wherein the restriction member comprises a band and a clip.

45. The sheath system kit of claim 20, wherein the restriction member comprises a band and a pin.

46. The sheath system kit of claim 20, wherein the restriction member comprises a clamp and a clip.

47. The sheath system kit of claim 20, wherein the restriction member comprises a clamp and a pin.

48. The sheath system kit of claim 20, wherein the restriction member comprises a clip and a pin.

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