Patent Publication Number: US-2022218355-A1

Title: Medical system for treating a left atrial appendage

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority of U.S. Provisional Application No. 63/137,387 filed Jan. 14, 2021, the entire disclosure of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The disclosure relates generally to medical devices and more particularly to medical devices that are adapted for use in percutaneous medical procedures including implantation into the left atrial appendage (LAA) of a heart. 
     BACKGROUND 
     The left atrial appendage is a small organ attached to the left atrium of the heart. During normal heart function, as the left atrium constricts and forces blood into the left ventricle, the left atrial appendage constricts and forces blood into the left atrium. The ability of the left atrial appendage to contract assists with improved filling of the left ventricle, thereby playing a role in maintaining cardiac output. However, in patients suffering from atrial fibrillation, the left atrial appendage may not properly contract or empty, causing stagnant blood to pool within its interior, which can lead to the undesirable formation of thrombi within the left atrial appendage. 
     Thrombi forming in the left atrial appendage may break loose from this area and enter the blood stream. Thrombi that migrate through the blood vessels may eventually plug a smaller vessel downstream and thereby contribute to stroke or heart attack. Clinical studies have shown that the majority of blood clots in patients with atrial fibrillation originate in the left atrial appendage. As a treatment, medical devices have been developed which are deployed to close off the left atrial appendage. Of the known medical devices and methods, each has certain advantages and disadvantages. There is an ongoing need to provide alternative medical devices and introducers as well as alternative methods for manufacturing and using medical devices and introducers. 
     SUMMARY 
     In one example, a medical system may comprise a left atrial appendage closure device including an expandable framework and a proximal hub disposed along a central longitudinal axis of the expandable framework, the expandable framework being configured to shift between a collapsed delivery configuration and an expanded deployed configuration; wherein the left atrial appendage closure device includes a sensor at least partially disposed within an interior of the expandable framework and axially movable relative to the proximal hub; wherein the proximal hub includes a first threaded connection structure; and a delivery catheter including a core wire extending axially within a lumen of the delivery catheter, the core wire having a second threaded connection structure at a distal end thereof configured to releasably engage the first threaded connection structure in an unreleased configuration. 
     In addition or alternatively to any example disclosed herein, the sensor is a pressure sensor configured to sense a fluid pressure within a space facing a proximal end of the sensor when the left atrial appendage closure device is in a released configuration. 
     In addition or alternatively to any example disclosed herein, when the second threaded connection structure is engaged with the first threaded connection structure, a distal end of the second threaded connection structure engages a proximal end of the sensor. 
     In addition or alternatively to any example disclosed herein, when the second threaded connection structure is disengaged from the first threaded connection structure, the sensor is at least partially disposed within the proximal hub. 
     In addition or alternatively to any example disclosed herein, when the second threaded connection structure is disengaged from the first threaded connection structure, a proximal end of the sensor extends proximal of the proximal hub. 
     In addition or alternatively to any example disclosed herein, the left atrial appendage closure device includes at least one spring engaged with the proximal hub and the sensor. 
     In addition or alternatively to any example disclosed herein, the at least one spring is one coil spring disposed coaxially about the sensor. 
     In addition or alternatively to any example disclosed herein, the at least one spring includes a plurality of springs spaced circumferentially around the sensor. 
     In addition or alternatively to any example disclosed herein, the at least one spring is fixedly attached to an inner surface of the proximal hub. 
     In addition or alternatively to any example disclosed herein, the sensor includes a third threaded connection structure configured to threadably couple the sensor to the first threaded connection structure. 
     In addition or alternatively to any example disclosed herein, when the left atrial appendage closure device is not in a released configuration, rotation of the core wire relative to the proximal hub rotates the sensor relative to the proximal hub. 
     In addition or alternatively to any example disclosed herein, a medical system may comprise a left atrial appendage closure device including an expandable framework and a proximal hub disposed along a central longitudinal axis of the expandable framework, the expandable framework being configured to shift between a collapsed delivery configuration and an expanded deployed configuration; wherein the left atrial appendage closure device includes a sensor at least partially disposed within an interior of the expandable framework and axially movable relative to the proximal hub; wherein the proximal hub includes a first threaded connection structure; and a delivery catheter including a core wire extending axially within a lumen of the delivery catheter, the core wire having a second threaded connection structure at a distal end thereof configured to releasably engage the first threaded connection structure in an unreleased configuration; wherein the sensor includes an annular ledge extending radially outward from an outer surface of the sensor. 
     In addition or alternatively to any example disclosed herein, the annular ledge is axially closer to a distal end of the proximal hub in a released configuration than in the unreleased configuration. 
     In addition or alternatively to any example disclosed herein, the annular ledge is configured to engage the proximal hub when the left atrial appendage closure device is in a released configuration. 
     In addition or alternatively to any example disclosed herein, in a released configuration, the sensor occupies at least 70% of a volume defined by the first threaded connection structure. 
     In addition or alternatively to any example disclosed herein, a medical system may comprise a left atrial appendage closure device including an expandable framework and a proximal hub disposed along a central longitudinal axis of the expandable framework, the expandable framework being configured to shift between a collapsed delivery configuration and an expanded deployed configuration; wherein the left atrial appendage closure device includes a sensor at least partially disposed within an interior of the expandable framework and axially movable relative to the proximal hub; wherein the proximal hub includes a first connection structure; and a delivery catheter including a core wire extending axially within a lumen of the delivery catheter, the core wire having a second connection structure at a distal end thereof configured to releasably engage the first connection structure in an unreleased configuration; wherein an occlusive element is disposed over at least a portion of the expandable framework. 
     In addition or alternatively to any example disclosed herein, the expandable framework includes a plurality of interconnected struts joined together at the proximal hub. 
     In addition or alternatively to any example disclosed herein, the first connection structure is formed on an inside surface of the proximal hub the second connection structure is formed on an outside surface of the core wire. 
     In addition or alternatively to any example disclosed herein, at least one spring is disposed between the proximal hub and the sensor in tension. 
     In addition or alternatively to any example disclosed herein, at least one spring is disposed between the proximal hub and the sensor in compression. 
     The above summary of some embodiments, aspects, and/or examples is not intended to describe each embodiment or every implementation of the present disclosure. The figures and the detailed description which follows more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which: 
         FIGS. 1-2  are side views of an example medical system; 
         FIGS. 3-4  illustrate aspects of a left atrial appendage closure device; 
         FIG. 5  is a partial cutaway view of an example configuration of the left atrial appendage closure device in a released configuration; 
         FIG. 6  is a partial cutaway view of the example configuration of the left atrial appendage closure device of  FIG. 5  in an unreleased configuration; 
         FIG. 7  is a partial cutaway view of an example configuration of the left atrial appendage closure device in a released configuration; 
         FIG. 8  is a partial cutaway view of the example configuration of the left atrial appendage closure device of  FIG. 7  in an unreleased configuration; 
         FIG. 9  is a partial cutaway view of an example configuration of the left atrial appendage closure device in a released configuration; 
         FIG. 10  is a partial cutaway view of the example configuration of the left atrial appendage closure device of  FIG. 9  in an unreleased configuration; 
         FIG. 11  is a partial cutaway view of an example configuration of the left atrial appendage closure device in a released configuration; 
         FIG. 12  is a partial cutaway view of the example configuration of the left atrial appendage closure device of  FIG. 11  in an unreleased configuration; 
         FIG. 13A-13C  illustrate aspects of the medical system associated with the example configuration of the left atrial appendage closure device of  FIG. 11 ; and 
         FIG. 14  illustrates the left atrial appendage closure device disposed within the ostium of a left atrial appendage of a patient&#39;s heart. 
     
    
    
     While aspects of the disclosure are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. 
     DETAILED DESCRIPTION 
     The following description should be read with reference to the drawings, which are not necessarily to scale, wherein like reference numerals indicate like elements throughout the several views. The detailed description and drawings are intended to illustrate but not limit the current disclosure. Those skilled in the art will recognize that the various elements described and/or shown may be arranged in various combinations and configurations without departing from the scope of the disclosure. The detailed description and drawings illustrate example embodiments of the current disclosure. However, in the interest of clarity and ease of understanding, while every feature and/or element may not be shown in each drawing, the feature(s) and/or element(s) may be understood to be present regardless, unless otherwise specified. 
     For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. 
     All numeric values are herein assumed to be modified by the term “about,” whether or not explicitly indicated. The term “about”, in the context of numeric values, generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the term “about” may include numbers that are rounded to the nearest significant figure. Other uses of the term “about” (e.g., in a context other than numeric values) may be assumed to have their ordinary and customary definition(s), as understood from and consistent with the context of the specification, unless otherwise specified. 
     The recitation of numerical ranges by endpoints includes all numbers within that range, including the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). 
     Although some suitable dimensions, ranges, and/or values pertaining to various components, features and/or specifications are disclosed, one of skill in the art, incited by the present disclosure, would understand desired dimensions, ranges, and/or values may deviate from those expressly disclosed. 
     As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. It is to be noted that in order to facilitate understanding, certain features of the disclosure may be described in the singular, even though those features may be plural or recurring within the disclosed example(s). Each instance of the features may include and/or be encompassed by the singular disclosure(s), unless expressly stated to the contrary. For simplicity and clarity purposes, not all elements of the current disclosure are necessarily shown in each figure or discussed in detail below. However, it will be understood that the following discussion may apply equally to any and/or all of the components for which there are more than one, unless explicitly stated to the contrary. Additionally, not all instances of some elements or features may be shown in each figure for clarity. 
     Relative terms such as “proximal”, “distal”, “advance”, “retract”, variants thereof, and the like, may be generally considered with respect to the positioning, direction, and/or operation of various elements relative to a user/operator/manipulator of the device, wherein “proximal” and “retract” indicate or refer to closer to or toward the user and “distal” and “advance” indicate or refer to farther from or away from the user. In some instances, the terms “proximal” and “distal” may be arbitrarily assigned in an effort to facilitate understanding of the disclosure, and such instances will be readily apparent to the skilled artisan. Other relative terms, such as “upstream”, “downstream”, “inflow”, and “outflow” refer to a direction of fluid flow within a lumen, such as a body lumen, a blood vessel, or within a device. Still other relative terms, such as “axial”, “circumferential”, “longitudinal”, “lateral”, “radial”, etc. and/or variants thereof generally refer to direction and/or orientation relative to a central longitudinal axis of the disclosed structure or device. 
     The term “extent” may be understood to mean a greatest measurement of a stated or identified dimension, unless the extent or dimension in question is preceded by or identified as a “minimum”, which may be understood to mean a smallest measurement of the stated or identified dimension. For example, “outer extent” may be understood to mean an outer dimension, “radial extent” may be understood to mean a radial dimension, “longitudinal extent” may be understood to mean a longitudinal dimension, etc. Each instance of an “extent” may be different (e.g., axial, longitudinal, lateral, radial, circumferential, etc.) and will be apparent to the skilled person from the context of the individual usage. Generally, an “extent” may be considered a greatest possible dimension measured according to the intended usage, while a “minimum extent” may be considered a smallest possible dimension measured according to the intended usage. In some instances, an “extent” may generally be measured orthogonally within a plane and/or cross-section, but may be, as will be apparent from the particular context, measured differently—such as, but not limited to, angularly, radially, circumferentially (e.g., along an arc), etc. 
     The terms “monolithic” and “unitary” shall generally refer to an element or elements made from or consisting of a single structure or base unit/element. A monolithic and/or unitary element shall exclude structure and/or features made by assembling or otherwise joining multiple discrete structures or elements together. 
     It is noted that references in the specification to “an embodiment”, “some embodiments”, “other embodiments”, etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of one skilled in the art to implement the particular feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described, unless clearly stated to the contrary. That is, the various individual elements described below, even if not explicitly shown in a particular combination, are nevertheless contemplated as being combinable or arrangeable with each other to form other additional embodiments or to complement and/or enrich the described embodiment(s), as would be understood by one of ordinary skill in the art. 
     For the purpose of clarity, certain identifying numerical nomenclature (e.g., first, second, third, fourth, etc.) may be used throughout the description and/or claims to name and/or differentiate between various described and/or claimed features. It is to be understood that the numerical nomenclature is not intended to be limiting and is exemplary only. In some embodiments, alterations of and deviations from previously used numerical nomenclature may be made in the interest of brevity and clarity. That is, a feature identified as a “first” element may later be referred to as a “second” element, a “third” element, etc. or may be omitted entirely, and/or a different feature may be referred to as the “first” element. The meaning and/or designation in each instance will be apparent to the skilled practitioner. 
     The following figures illustrate selected components and/or arrangements of an implant for occluding the left atrial appendage, a medical system for occluding the left atrial appendage, and/or methods of using the implant and/or the medical system. It should be noted that in any given figure, some features may not be shown, or may be shown schematically, for simplicity. Additional details regarding some of the components of the implant and/or the system may be illustrated in other figures in greater detail. While discussed in the context of occluding the left atrial appendage, the implant and/or the system may also be used for other interventions and/or percutaneous medical procedures within a patient. Similarly, the devices and methods described herein with respect to percutaneous deployment may be used in other types of surgical procedures, as appropriate. For example, in some examples, the devices may be used in a non-percutaneous procedure. Devices and methods in accordance with the disclosure may also be adapted and configured for other uses within the anatomy. 
     Turning now to the figures,  FIGS. 1-2  illustrate a medical system  10  including an delivery catheter  40  having a lumen  42  extending from a proximal opening to a distal opening, a core wire  30  slidably disposed and/or extending axially within the lumen  42  of the delivery catheter  40 , and a left atrial appendage closure device  100  having an expandable framework  110  configured to shift between a collapsed delivery configuration (e.g.,  FIG. 1 ), wherein the left atrial appendage closure device  100  is disposed within the lumen  42  proximate the distal opening in the collapsed delivery configuration, and an expanded deployed configuration (e.g.,  FIG. 2 ). The left atrial appendage closure device  100  and/or the expandable framework  110  may be configured to shift between the collapsed delivery configuration and the expanded deployed configuration when the left atrial appendage closure device  100  is disposed distal of the distal opening of the lumen  42  and/or the delivery catheter  40 , and/or when the left atrial appendage closure device  100  is unconstrained by the delivery catheter  40 . The left atrial appendage closure device  100  may be disposed at and/or releasably connected to a distal portion of the core wire  30 . The core wire  30  may be slidably and/or rotatably disposed within the lumen  42  of the delivery catheter  40 . In some embodiments, a proximal end of the core wire  30  may extend proximally of a proximal end of the delivery catheter  40  and/or the proximal opening of the lumen  42  for manual manipulation by a clinician or practitioner. In some embodiments, the example left atrial appendage closure device  100  may be releasably engaged with, removably attached to, or otherwise releasably connected to the distal end of the core wire  30 . Some suitable, but non-limiting, examples of materials for the medical system  10 , the core wire  30 , the delivery catheter  40 , and/or the left atrial appendage closure device  100 , etc. are discussed below. It is contemplated that any and/or all example occlusive implants disclosed herein may be used in accordance with and/or be associated with the example medical system  10  described above. 
       FIGS. 3-4  illustrate an example configuration of the left atrial appendage closure device  100  comprising the expandable framework  110  configured to shift between the collapsed delivery configuration and the expanded deployed configuration. In some embodiments, the left atrial appendage closure device  100  may include a proximal hub  130  disposed along a central longitudinal axis of the expandable framework  110 . In some embodiments, the proximal hub  130  may be centered on the central longitudinal axis of the expandable framework  110 . For example, the proximal hub  130  may be coaxial with the central longitudinal axis of the expandable framework  110 . In some embodiments, the expandable framework  110  may include a plurality of interconnected struts joined together at the proximal hub  130 . In some embodiments, the proximal hub  130  may be integrally formed with and/or may be monolithically formed with the expandable framework  110  and/or the plurality of interconnected struts. In some embodiments, the left atrial appendage closure device  100  may include, and/or the expandable framework  110  may be, a self-expanding framework. 
     The expandable framework  110  may be compliant and substantially conform to and/or be in sealing engagement with the shape and/or geometry of a lateral wall and/or an ostium of a left atrial appendage in the expanded deployed configuration. In some embodiments, the left atrial appendage closure device  100  may expand to a size, extent, or shape less than or different from a maximum unconstrained extent, as determined by the surrounding tissue and/or lateral wall of the left atrial appendage. In some embodiments, reducing a thickness of various elements of the expandable framework  110  may increase the flexibility and compliance of the expandable framework  110  and/or the left atrial appendage closure device  100 , thereby permitting the expandable framework  110  and/or the left atrial appendage closure device  100  to conform to the tissue around it, rather than forcing the tissue to conform to the expandable framework  110  and/or the left atrial appendage closure device  100 . 
     In some embodiments, the left atrial appendage closure device  100  may optionally include an occlusive element  120  (e.g., a mesh, a fabric, a membrane, and/or other surface treatment) disposed on, disposed over, disposed about, or covering at least a portion of the expandable framework  110 , as seen in  FIG. 3 . In some embodiments, the occlusive element  120  may be disposed on, disposed over, disposed about or cover at least a portion of an outer (or outwardly facing) surface of the expandable framework  110 . In some embodiments, the occlusive element  120  may be secured to and/or may extend radially outward from the proximal hub  130 . For reference, the occlusive element  120  has been removed from  FIG. 4  to show selected aspects of the left atrial appendage closure device  100  otherwise hidden from view by the occlusive element  120 . 
     In some embodiments, the expandable framework  110  may include a plurality of anchor members  112  disposed about a periphery of the expandable framework  110  in the expanded deployed configuration. The plurality of anchor members  112  may extend radially outward from the expandable framework  110 . In some embodiments, at least some of the plurality of anchor members  112  may each have and/or include a body portion, a tip portion, and a barb projecting circumferentially therefrom. In some embodiments, some and/or each of the plurality of anchor members  112  have at least one barb projecting circumferentially therefrom. Some suitable, but non-limiting, examples of materials for the expandable framework  110 , the plurality of anchor members  112 , etc. are discussed below. 
     In some embodiments, the plurality of anchor members  112  may provide an anchoring mechanism to aid in retaining the left atrial appendage closure device  100  at a target site within a patient&#39;s anatomy (i.e., the left atrial appendage, for example) in the expanded deployed configuration. However, the barb(s) may be configured, positioned, and/or arranged such that engagement of the barb(s) with surrounding tissue at the target site is minimized or avoided. For example, the barb(s) may not puncture, pierce, and/or extend into the surrounding tissue in the expanded deployed configuration. Additionally, in some embodiments, the plurality of anchor members  112  may provide an attachment mechanism for securing the occlusive element  120  to the expandable framework  110 . 
     In some embodiments, the occlusive element  120  may extend distally past at least some of the plurality of anchor members  112 . In some embodiments, the occlusive element  120  may extend distally past each and/or all of the plurality of anchor members  112 . In at least some embodiments, at least a distal portion of the occlusive element  120  may be attached to the expandable framework  110 . In some embodiments, at least some of the plurality of anchor members  112  extend and/or project through the occlusive element  120 . In some embodiments, each and/or all of the plurality of anchor members  112  extend and/or project through the occlusive element  120 . In some embodiments, the occlusive element  120  may be attached to the expandable framework  110  at some and/or each of the plurality of anchor members  112 , for example, by passing some and/or each of the plurality of anchor members  112  through the occlusive element  120 . 
     In some embodiments, the barb and/or the tip portion on some and/or each of the at least some of the plurality of anchor members  112  may be disposed radially outward of the occlusive element  120  and/or exterior of the occlusive element  120  while the base of its respective anchor member is disposed radially inward of and/or interior of the occlusive element  120 . The barb may serve to retain the occlusive element  120  on the expandable framework  110 , thereby preventing the occlusive element  120  from working loose and/or releasing from the expandable framework  110  as the expandable framework  110  is shifted between the collapsed delivery configuration and the expanded deployed configuration. In some embodiments, attachment of the distal portion of the occlusive element  120  to the expandable framework  110  is devoid of sutures and/or adhesives. 
     In some embodiments, the occlusive element  120  may be permeable, semi-permeable, or impermeable to blood and/or other fluids, such as water. In some embodiments, the occlusive element  120  may include a polymeric membrane, a metallic or polymeric mesh, a porous filter-like material, or other suitable construction. In some embodiments, the occlusive element  120  may be configured to prevent thrombi (i.e. blood clots, etc.) from passing through the occlusive element  120  and/or exiting the left atrial appendage into the blood stream when the left atrial appendage closure device  100  and/or the expandable framework  110  is disposed within an ostium of the left atrial appendage in the expanded deployed configuration. In some embodiments, the occlusive element  120  may be configured to promote endothelization across the ostium of the left atrial appendage after implantation of the left atrial appendage closure device  100 , thereby effectively removing the left atrial appendage from the patient&#39;s circulatory system. Some suitable, but non-limiting, examples of materials for the occlusive element  120  are discussed below. 
     In some embodiments, the left atrial appendage closure device  100  may include a sensor  140  at least partially disposed within an interior of the expandable framework  110  and axially movable relative to the proximal hub  130  and/or the expandable framework  110 . In some alternative embodiments, the left atrial appendage closure device  100  may include a plug and/or a stopper in place of the sensor  140 , wherein the plug and/or the stopper is at least partially disposed within the interior of the expandable framework  110  and axially movable relative to the proximal hub  130  and/or the expandable framework  110 . In some embodiments, the sensor  140 , and/or the plug and/or the stopper, as described and/or positioned as described herein, may be useful for reducing exposed surface area of the proximal hub  130  and/or reducing the risk of thrombus formation. 
     In at least some embodiments, the sensor  140 , and/or the plug and/or the stopper, may be at least partially disposed within the proximal hub  130  in a released configuration of the medical system  10  and/or the left atrial appendage closure device  100 , as seen in  FIGS. 3 and 4 . In the released configuration, the core wire  30  may be disengaged from and/or detached from the left atrial appendage closure device  100  and/or the proximal hub  130 , as discussed herein. In some embodiments, a proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may be disposed substantially flush with a proximalmost extent of the proximal hub  130  in the released configuration. In some embodiments, the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may extend proximal of the proximalmost extent of the proximal hub  130  in the released configuration. For example, in some embodiments, the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may extend about 1 millimeter (mm), about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, or about 10 mm proximal of the proximalmost extent of the proximal hub  130  in the released configuration. In one example, the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may extend about 4 mm to about 5 mm proximal of the proximalmost extent of the proximal hub  130  in the released configuration. Other ranges and/or dimensions are also contemplated. In some embodiments, the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may have a convex shape extending in the proximal direction. In some embodiments having the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, with a convex shape, a proximalmost extent of the sensor  140 , and/or the plug and/or the stopper, may be substantially flush with the proximalmost extent of the proximal hub  130  in the released configuration. In some embodiments having the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, with a convex shape, the proximalmost extent of the sensor  140 , and/or the plug and/or the stopper, may extend proximal of the proximalmost extent of the proximal hub  130  in the released configuration. 
     In some embodiments, having the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, extend proximal of the proximalmost extent of the proximal hub  130  in the released configuration may permit endothelial growth over the occlusive element  120  and/or the ostium of the left atrial appendage without obstructing and/or obscuring the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper. In some embodiments, the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may be disposed distal of the proximalmost extent of the proximal hub  130  and proximal of a distal end of the proximal hub  130  in the released configuration such that the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, is recessed within the proximal hub  130  to permit and/or promote endothelial growth thereover. The skilled artisan will recognize that the type, construction, and capabilities of the sensor  140 , and/or the plug and/or the stopper, may be used to determine whether or not endothelial overgrowth should be permitted and/or promoted. 
     As shown in  FIG. 4 , the sensor  140 , and/or the plug and/or the stopper, may extend distally into the interior of the left atrial appendage closure device  100  and/or the expandable framework  110 . In some embodiments, the sensor  140 , and/or the plug and/or the stopper, may have a substantially cylindrical outer surface. In some embodiments, the sensor  140 , and/or the plug and/or the stopper, may be hollow and/or may include an interior space configured to house components of the sensor  140 , and/or the plug and/or the stopper. An overall length of the sensor  140 , and/or the plug and/or the stopper, may vary depending on the construction of the sensor  140 , and/or the plug and/or the stopper, and/or components disposed within the interior space of the sensor  140 , and/or the plug and/or the stopper. 
     In one example configuration, the sensor  140 , and/or the plug and/or the stopper, may include one or more internal components disposed within the interior space. In some embodiments, the sensor  140 , and/or the plug and/or the stopper, may be devoid of any internal components. As such, any and/or all of the internal components may be considered optional in any particular example. In some embodiments, the sensor  140  may include a sensing element disposed within the sensor  140 , the sensing element being in communication with the proximal end  142  of the sensor  140 . In some embodiments, the sensor  140  may be a pressure sensor and/or may include a pressure sensing element. In some embodiments, the proximal end  142  of the sensor  140  may include a diaphragm extending across the proximal end  142  of the sensor  140 , and a pressure transfer fluid may be disposed within the proximal end  142  of the sensor  140  between the diaphragm and the sensing element. The sensor  140  may be configured to sense a fluid pressure within a space facing the proximal end  142  of the sensor  140  (e.g., a left atrium) and/or adjacent the proximal end  142  of the sensor  140  when the expandable framework  110  and/or the left atrial appendage closure device  100  is disposed within an ostium of the left atrial appendage in the delivery configuration and/or in the released configuration. In some embodiments, the sensor  140  may be configured to sense and/or detect (and/or the sensor  140  may include a sensing element configured to sense and/or detect) temperature, flow rate, heart rate, electrical signals in the heart, heart rhythm, or other characteristics. 
     In some embodiments, the sensor  140  may include an integrated circuit board for controlling the sensor  140  and/or other internal components of the sensor  140 . In some embodiments, the sensor  140  may include a communication coil disposed within the interior space of the sensor  140 . In some embodiments, the communication coil may be configured for bi-directional wireless communication and/or energy transfer. In some embodiments, the sensor  140  may optionally include a battery. In some embodiments, the sensor  140  may be powered “on-demand” via an inductive link. In some embodiments, the communication coil may be and/or may form a part of the inductive link. In some embodiments, the sensor  140  may include a capacitor disposed within the interior space configured to act as a temporary power source for the sensor  140  and/or other internal components of the sensor  140  (during “on-demand” energy transfer to the sensor  140  and/or the left atrial appendage closure device  100 , for example). In some embodiments, the communication coil may be wrapped around the battery. In some embodiments, the communication coil may be wrapped around the capacitor. In some embodiments, the communication coil may be a stand-alone feature and/or may be wrapped around an inert and/or non-functional structure to maintain shape and/or form. Other configurations are also contemplated. 
     In some embodiments utilizing the battery, the battery may be rechargeable. While a direct connection may be used to recharge the battery, such a configuration may be rather invasive to the patient. Accordingly, a wireless (e.g., inductive) recharging capability may be more desirable and far less invasive to the patient. In some embodiments, utilizing the battery, the battery may not be rechargeable. When using a non-rechargeable battery, it may be desirable to use a battery having a lifetime at least as long as the expected remaining lifetime of the patient to avoid needing to replace the battery during a patient&#39;s later years when surgical procedures may be more challenging. 
       FIGS. 5-12  illustrate aspects of an example configuration of the medical system  10 .  FIGS. 5, 7, 9, and 11  illustrate the medical system  10  and/or the left atrial appendage closure device  100  in the released configuration. In the released configuration, the core wire  30  (not shown) may be disengaged and/or detached from the left atrial appendage closure device  100  and/or the proximal hub  130 .  FIGS. 6, 8, 10, and 12  illustrate the medical system  10  and/or the left atrial appendage closure device  100  in the unreleased configuration. In the unreleased configuration, the core wire  30  may be at least partially releasably engaged with, attached to, and/or connected to the left atrial appendage closure device  100  and/or the proximal hub  130 . In at least some embodiments, the collapsed delivery configuration and/or the expanded deployed configuration may be used and/or applied concurrently and/or interchangeably with the unreleased configuration. For the purpose of this disclosure, any configuration where the core wire  30  is at least partially engaged with the left atrial appendage closure device  100  and/or the proximal hub  130  may be considered an unreleased configuration. 
     In some embodiments, the proximal hub  130  of the expandable framework  110  may be configured to releasably attach, join, couple, engage, or otherwise connect to the distal end of the core wire  30 . In some embodiments, the proximal hub  130  may include a first threaded connection structure  170  configured to and/or adapted to releasably couple with, join to, mate with, or otherwise engage with a second threaded connection structure  180  at the distal end of the core wire  30  in the unreleased configuration of the medical system  10  and/or the left atrial appendage closure device  100 , as shown in  FIGS. 6, 8, 10, and 12 . In some embodiments, the first threaded connection structure  170  may be formed on an inside surface of the proximal hub  130 . In some embodiments, the second threaded connection structure  180  may be formed on an outside surface of the core wire  30 . Additionally, in some embodiments, the first and/or second connection structure(s) need not be threaded. Other configurations are also contemplated, including but not limited to snap fits, engagement clips, spring features, cooperating protrusions and recesses, etc. 
     In some embodiments, when the second threaded connection structure  180  is disengaged from the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration, the sensor  140  is at least partially disposed within the proximal hub  130 . As may be seen in  FIGS. 5-12 , the sensor  140 , and/or the plug and/or the stopper, may be axially movable relative to the proximal hub  130  and/or the expandable framework  110 . In some embodiments, when the second threaded connection structure  180  is disengaged from the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration, the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may be substantially flush with the proximalmost extent of the proximal hub  130  in the released configuration, as generally shown in  FIGS. 5, 7, 9, and 11 . In some embodiments, when the second threaded connection structure  180  is disengaged from the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration, the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may extend proximal of the proximalmost extent of the proximal hub  130  in the released configuration, as shown in phantom at reference number  143  in  FIGS. 5, 7, 9, and 11 . When the second threaded connection structure  180  is engaged with the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the unreleased configuration, a distal end of the second threaded connection structure  180  and/or the distal end of the core wire  30  may engage the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, as seen in  FIGS. 6, 8, 10, and 12 . 
     In some embodiments, the distal end of the second threaded connection structure  180  and/or the distal end of the core wire  30  may have a concave shape extending proximally. The concave shape may be configured to engage, abut, and/or mate with the convex shape of the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, when the second threaded connection structure  180  is engaged with the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the unreleased configuration. In some embodiments, the distal end of the second threaded connection structure  180  and/or the distal end of the core wire  30  may be in direct contact with the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, when the second threaded connection structure  180  is engaged with the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the unreleased configuration. 
     In some embodiments, when the second threaded connection structure  180  is disengaged from the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration, the sensor  140 , and/or the plug and/or the stopper, may occupy at least 50% of a volume defined by the first threaded connection structure  170 . In some embodiments, when the second threaded connection structure  180  is disengaged from the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration, the sensor  140 , and/or the plug and/or the stopper, may occupy at least 60% of the volume defined by the first threaded connection structure  170 . In some embodiments, when the second threaded connection structure  180  is disengaged from the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration, the sensor  140 , and/or the plug and/or the stopper, may occupy at least 70% of the volume defined by the first threaded connection structure  170 . In some embodiments, when the second threaded connection structure  180  is disengaged from the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration, the sensor  140 , and/or the plug and/or the stopper, may occupy at least 80% of the volume defined by the first threaded connection structure  170 . In some embodiments, when the second threaded connection structure  180  is disengaged from the first threaded connection structure  170 , and/or when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration, the sensor  140 , and/or the plug and/or the stopper, may occupy at least 90% of the volume defined by the first threaded connection structure  170 . 
     In some embodiments, the sensor  140 , and/or the plug and/or the stopper, may include an annular ledge  144  extending radially outward from the outer surface of the sensor  140 , and/or the plug and/or the stopper. In some embodiments, the annular ledge  144  may be oriented substantially perpendicular to the central longitudinal axis and/or to the outer surface of the sensor  140 , and/or the plug and/or the stopper. In at least some embodiments, the outer surface of the sensor  140 , and/or the plug and/or the stopper, may be substantially cylindrical in shape. The annular ledge  144  may extend circumferentially about and/or around the outer surface of the sensor  140 , and/or the plug and/or the stopper. The annular ledge  144  may be disposed between and axially spaced apart from the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, and a distal end of the sensor  140 , and/or the plug and/or the stopper. In some embodiments, the annular ledge  144  may be axially closer to the distal end and/or the distalmost extent of the proximal hub  130  in the released configuration than in the unreleased configuration. In some embodiments, the annular ledge  144  may be configured to engage and/or abut the proximal hub  130  when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration. In some embodiments, the annular ledge  144  may be configured to engage and/or abut the distal end of the proximal hub  130  when the left atrial appendage closure device  100  and/or the medical system  10  is in the released configuration. In some embodiments, the annular ledge  144  may be discontinuous about and/or around the outer surface of the sensor  140 , and/or the plug and/or the stopper. For example, in some embodiments, the annular ledge  144  may comprise a plurality of individual ledges spaced circumferentially about and/or around the outer surface of the sensor  140 , and/or the plug and/or the stopper, at a common axial location between the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, and the distal end of the sensor  140 , and/or the plug and/or the stopper. In some embodiments, the annular ledge  144  may include a proximal taper, a distal taper, or both to facilitate axial movement of the sensor  140 , and/or the plug and/or the stopper, relative to the proximal hub  130  and/or to aid in aligning the sensor  140 , and/or the plug and/or the stopper, 40 with the first threaded connection structure  170  and/or the volume defined by the first threaded connection structure  170 . In some embodiments, the annular ledge  144  may include the proximal taper, the distal taper, or both to urge the sensor  140 , and/or the plug and/or the stopper, into coaxial alignment with the central longitudinal axis of the left atrial appendage closure device  100  and/or the expandable framework  110 . 
     In some embodiments, the left atrial appendage closure device  100  may include at least one spring  150  engaged with the proximal hub  130  and the sensor  140 , and/or the plug and/or the stopper. In some embodiments, the at least one spring  150  may be coupled to the proximal hub  130  and/or the sensor  140 , and/or the plug and/or the stopper. In some embodiments, the at least one spring  150  may be fixedly attached to an inner surface of the proximal hub  130 . In some embodiments, the at least one spring may be fixedly attached to the sensor  140 , and/or the plug and/or the stopper, and/or the annular ledge  144 . In some embodiments, the at least one spring  150  may include a plurality of springs spaced circumferentially about and/or around the sensor  140 , and/or the plug and/or the stopper, and/or the outer surface of the sensor  140 . In some embodiments, the at least one spring  150  may each include and/or be formed as a coil spring, a mesh network with a spring function, or other suitable structure capable of providing a spring-like function. In some embodiments, the at least one spring  150  may include one coil spring disposed coaxially about the sensor  140 , and/or the plug and/or the stopper, as seen in  FIGS. 9 and 10 . In some embodiments, the at least one spring  150  may be disposed between the proximal hub  130  and the sensor  140 , and/or the plug and/or the stopper, in tension, as seen in  FIGS. 5 and 6 . In some embodiments, the at least one spring  150  may be disposed between the proximal hub  130  and the annular ledge  144  of the sensor  140 , and/or the plug and/or the stopper, in tension. In some embodiments, the at least one spring  150  may be disposed between the proximal hub  130  and the sensor  140 , and/or the plug and/or the stopper, in compression, as seen in  FIGS. 7-10 . In some embodiments, the at least one spring  150  may be disposed between the proximal hub  130  and the annular ledge  144  of the sensor  140 , and/or the plug and/or the stopper, in compression. In some embodiments, the at least one spring  150  may be disposed between the proximal hub  130  and a proximal flange  146  disposed at the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, as seen in  FIGS. 9 and 10 . The proximal flange  146  may extend radially outward from the outer surface of the sensor  140 , and/or the plug and/or the stopper, in a manner similar to the annular ledge  144 . In some embodiments, the proximal flange  146  may extend substantially perpendicular to the central longitudinal axis and/or to the outer surface of the sensor  140 , and/or the plug and/or the stopper. 
     In some embodiments, the sensor  140 , and/or the plug and/or the stopper, may include a third threaded connection structure  148  formed on the outside surface of the sensor  140 , and/or the plug and/or the stopper, proximate the proximal end  142  and configured to threadably couple the sensor  140 , and/or the plug and/or the stopper, to the first threaded connection structure  170 , as seen in  FIG. 11 . In some embodiments, when the left atrial appendage closure device  100  is not in the released configuration, rotation of the core wire  30  relative to the proximal hub  130  may rotate the sensor  140 , and/or the plug and/or the stopper, relative to the proximal hub  130  to axially move the sensor  140 , and/or the plug and/or the stopper, relative to the proximal hub  130  and/or the expandable framework  110 , as seen in  FIG. 12 . In some embodiments, the first threaded connection structure  170  and the second threaded connection structure  180  may be configured such that when the left atrial appendage closure device  100  is not in the released configuration, clockwise rotation of the core wire  30  relative to the proximal hub  130  may advance the second threaded connection structure  180  distally within and with respect to the proximal hub  130  and the first threaded connection structure  170 , and counterclockwise rotation of the core wire  30  relative to the proximal hub  130  may withdraw the second threaded connection structure  180  proximally within and with respect to the proximal hub  130  and the first threaded connection structure  170 . In an alternative configuration, the first threaded connection structure  170  and the second threaded connection structure  180  may be configured such that when the left atrial appendage closure device  100  is not in the released configuration, counterclockwise rotation of the core wire  30  relative to the proximal hub  130  may advance the second threaded connection structure  180  distally within and with respect to the proximal hub  130  and the first threaded connection structure  170 , and clockwise rotation of the core wire  30  relative to the proximal hub  130  may withdraw the second threaded connection structure  180  proximally within and with respect to the proximal hub  130  and the first threaded connection structure  170 . 
     In some embodiments, the distal end of the core wire  30  and/or the second threaded connection structure  180  may include a first locking element  190  formed thereon, as seen in  FIGS. 13A-13C . In at least some embodiments, the first locking element  190  may extend distally from the second threaded connection structure  180 . In some embodiments, the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, may include a second locking element  192  formed thereon. In some embodiments, the second locking element  192  may extend distally into the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, and/or the second locking element  192  may be recessed into the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper. 
     In one example configuration shown in  FIG. 13A , the first locking element  190  may be a projection key extending axially parallel to the central longitudinal axis. The projection key may be disposed along a perimeter of the second threaded connection structure  180 . The second locking element  192  may be a notch formed in the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, proximate the outside surface of the sensor  140 , and/or the plug and/or the stopper. The projection key and the notch may be complimentary shapes configured such that the projection key is able to engage with and nest inside of the notch while preventing relative rotation therebetween. The projection key and the notch may each include flat sides configured to transmit rotational force therebetween such that rotational force applied to the core wire  30  is transmitted through the projection key and the notch to the sensor  140 , and/or the plug and/or the stopper. Accordingly, when the left atrial appendage closure device  100  is not in the released configuration, rotation applied to the core wire  30  results in corresponding rotation and axial movement of the sensor  140 , and/or the plug and/or the stopper, relative to the proximal hub  130 . 
     In another example configuration shown in  FIG. 13B , the first locking element  190  may be a hex key extending axially parallel to the central longitudinal axis. The hex key may be disposed coaxially with second threaded connection structure  180  and/or the core wire  30 . The second locking element  192  may be a hex recess formed in the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, coaxially with the sensor  140 , and/or the plug and/or the stopper. The hex key and the hex recess may be complimentary shapes configured such that the hex key is able to engage with and nest inside of the hex recess while preventing relative rotation therebetween. The hex key and the hex recess may each include straight sides (e.g., parallel to the central longitudinal axis) configured to transmit rotational force therebetween such that rotational force applied to the core wire  30  is transmitted through the hex key and the hex recess to the sensor  140 , and/or the plug and/or the stopper. Accordingly, when the left atrial appendage closure device  100  is not in the released configuration, rotation applied to the core wire  30  results in corresponding rotation and axial movement of the sensor  140 , and/or the plug and/or the stopper, relative to the proximal hub  130 . 
     In another example configuration shown in  FIG. 13C , the first locking element  190  may be a wave key extending axially parallel to the central longitudinal axis. The wave key may be disposed coaxially with second threaded connection structure  180  and/or the core wire  30 . The second locking element  192  may be a wave recess formed in the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper, coaxially with the sensor  140 , and/or the plug and/or the stopper. The wave key and the wave recess may be complimentary shapes configured such that the wave key is able to engage with and nest inside of the wave recess while preventing relative rotation therebetween. The wave key and the wave recess may each include straight sides (e.g., parallel to the central longitudinal axis) configured to transmit rotational force therebetween such that rotational force applied to the core wire  30  is transmitted through the wave key and the wave recess to the sensor  140 , and/or the plug and/or the stopper. Accordingly, when the left atrial appendage closure device  100  is not in the released configuration, rotation applied to the core wire  30  results in corresponding rotation and axial movement of the sensor  140 , and/or the plug and/or the stopper, relative to the proximal hub  130 . 
     The configurations shown in  FIGS. 13A-13C  are only examples and are not intended to be limiting. Other configurations and/or complimentary shapes including but not limited to a star shape, a square or rectangular shape, a triangular shape, a polygonal shape having a number sides not already mentioned here, an oval shape, irregular shapes, and/or other shapes that may prevent relative rotation between the first locking element  190  and the second locking element  192  are also contemplated for use as the first locking element  190  and the second locking element  192 . 
     In addition or alternatively to any configuration described herein, the core wire  30  may include at least one aperture extending through a side wall of the core wire into a hollow portion extending to the distal end of the core wire  30 . In the unreleased configuration, the at least one aperture may be disposed proximal of the sensor  140 , and/or the plug and/or the stopper. The at least one aperture may permit fluid communication between an exterior of the core wire  30  and the proximal end  142  of the sensor  140 , and/or the plug and/or the stopper. This may be useful when the practitioner wants to detect and/or measure left atrial pressure and/or other characteristics with the sensor  140  prior to releasing the left atrial appendage closure device  100 . 
       FIG. 14  is a partial cross-sectional view of an example left atrial appendage  50 , which may be attached to and in fluid communication with a left atrium  60  of a patient&#39;s heart. In some patients, the left atrial appendage  50  may have a complex geometry and/or irregular surface area. Skilled artisans will recognize that the illustrated left atrial appendage is merely one of many possible shapes and sizes for the left atrial appendage  50 , which may vary from patient to patient. Skilled artisans will also recognize that the medical devices, systems, and methods disclosed herein may be adapted for various sizes and shapes of the left atrial appendage  50 , as necessary. The left atrial appendage  50  may include a generally longitudinal axis arranged along a depth of a main body  52  of the left atrial appendage  50 . The main body  52  may include a wall  54  and an ostium  56  forming a proximal mouth  58 . In some embodiments, a lateral extent of the ostium  56  and/or the wall  54  may be smaller or less than a depth of the main body  52  along the longitudinal axis, or a depth of the main body  52  may be greater than a lateral extent of the ostium  56  and/or the wall  54 . In some embodiments, the left atrial appendage  50  may include a tail-like element associated with a distal portion of the main body  52 , which element may protrude radially or laterally away from the main body  52 . 
     As shown in  FIG. 14 , the left atrial appendage closure device  100  may be implanted within the ostium  56  of the left atrial appendage  50  to close off the proximal mouth  58  and substantially and/or completely sealing off the left atrial appendage  50  from the left atrium  60  and/or the patient&#39;s circulatory system. As noted herein, the sensor  140 , and/or the plug and/or the stopper, may face toward the left atrium  60 . In at least some embodiments, the sensor  140  may be a pressure sensor configured to sense fluid pressure within the left atrium  60  when the left atrial appendage closure device  100  is disposed within the ostium  56  of the left atrial appendage  50  in the released configuration. 
     The materials that can be used for the various components of the medical system  10  and/or the left atrial appendage closure device  100  and the various elements thereof disclosed herein may include those commonly associated with medical devices. For simplicity purposes, the following discussion refers to the medical system. However, this is not intended to limit the devices and methods described herein, as the discussion may be applied to other elements, members, components, or devices disclosed herein, such as, but not limited to, the core wire  30 , the delivery catheter  40 , the left atrial appendage closure device  100 , the expandable framework  110 , the occlusive element  120 , the proximal hub  130 , the sensor  140 , and/or elements or components thereof. 
     In some embodiments, the medical system and/or components thereof may be made from a metal, metal alloy, polymer (some examples of which are disclosed below), a metal-polymer composite, ceramics, combinations thereof, and the like, or other suitable material. 
     Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane (for example, Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), MARLEX® high-density polyethylene, MARLEX® low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS 50A), polycarbonates, polyurethane silicone copolymers (for example, ElastEon® from Aortech Biomaterials or ChronoSil® from AdvanSource Biomaterials), biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like. In some embodiments the sheath can be blended with a liquid crystal polymer (LCP). For example, the mixture can contain up to about 6 percent LCP. 
     Some examples of suitable metals and metal alloys include stainless steel, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY® C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; platinum; palladium; gold; combinations thereof; or any other suitable material. 
     In some embodiments, a linear elastic and/or non-super-elastic nickel-titanium alloy may be in the range of about 50 to about 60 weight percent nickel, with the remainder being essentially titanium. In some embodiments, the composition is in the range of about 54 to about 57 weight percent nickel. One example of a suitable nickel-titanium alloy is FHP-NT alloy commercially available from Furukawa Techno Material Co. of Kanagawa, Japan. Other suitable materials may include ULTANIUM™ (available from Neo-Metrics) and GUM METAL™ (available from Toyota). In some other embodiments, a superelastic alloy, for example a superelastic nitinol can be used to achieve desired properties. 
     In at least some embodiments, portions or all of the medical system and/or components thereof, may also be doped with, made of, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids the user of the medical system in determining its location. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloy, polymer material loaded with a radiopaque filler, and the like. Additionally, other radiopaque marker bands and/or coils may also be incorporated into the design of the medical system to achieve the same result. 
     In some embodiments, a degree of Magnetic Resonance Imaging (Mill) compatibility is imparted into the medical system and/or other elements disclosed herein. For example, the medical system and/or components or portions thereof may be made of a material that does not substantially distort the image and create substantial artifacts (i.e., gaps in the image). Certain ferromagnetic materials, for example, may not be suitable because they may create artifacts in an MRI image. The medical system or portions thereof may also be made from a material that the Mill machine can image. Some materials that exhibit these characteristics include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nitinol, and the like, and others. 
     In some embodiments, the medical system and/or other elements disclosed herein may include a fabric material disposed over or within the structure. The fabric material may be composed of a biocompatible material, such a polymeric material or biomaterial, adapted to promote tissue ingrowth. In some embodiments, the fabric material may include a bioabsorbable material. Some examples of suitable fabric materials include, but are not limited to, polyethylene glycol (PEG), nylon, polytetrafluoroethylene (PTFE, ePTFE), a polyolefinic material such as a polyethylene, a polypropylene, polyester, polyurethane, and/or blends or combinations thereof. 
     In some embodiments, the medical system and/or other elements disclosed herein may include and/or be formed from a textile material. Some examples of suitable textile materials may include synthetic yarns that may be flat, shaped, twisted, textured, pre-shrunk or un-shrunk. Synthetic biocompatible yarns suitable for use in the present disclosure include, but are not limited to, polyesters, including polyethylene terephthalate (PET) polyesters, polypropylenes, polyethylenes, polyurethanes, polyolefins, polyvinyls, polymethylacetates, polyamides, naphthalene dicarboxylene derivatives, natural silk, and polytetrafluoroethylenes. Moreover, at least one of the synthetic yarns may be a metallic yarn or a glass or ceramic yarn or fiber. Useful metallic yarns include those yarns made from or containing stainless steel, platinum, gold, titanium, tantalum or a Ni—Co—Cr-based alloy. The yarns may further include carbon, glass or ceramic fibers. Desirably, the yarns are made from thermoplastic materials including, but not limited to, polyesters, polypropylenes, polyethylenes, polyurethanes, polynaphthalenes, polytetrafluoroethylenes, and the like. The yarns may be of the multifilament, monofilament, or spun types. The type and denier of the yarn chosen may be selected in a manner which forms a biocompatible and implantable prosthesis and, more particularly, a vascular structure having desirable properties. 
     In some embodiments, the medical system and/or other elements disclosed herein may include and/or be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents may include anti-thrombogenic agents (such as heparin, heparin derivatives, urokinase, and PPack (dextrophenylalanine proline arginine chloromethylketone)); anti-proliferative agents (such as enoxaparin, angiopeptin, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory agents (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine); antineoplastic/antiproliferative/anti-mitotic agents (such as paclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin and thymidine kinase inhibitors); anesthetic agents (such as lidocaine, bupivacaine, and ropivacaine); anti-coagulants (such as D-Phe-Pro-Arg chloromethyl keton, an RGD peptide-containing compound, heparin, anti-thrombin compounds, platelet receptor antagonists, anti-thrombin antibodies, anti-platelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick antiplatelet peptides); vascular cell growth promoters (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional activators, and translational promoters); vascular cell growth inhibitors (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional repressors, translational repressors, replication inhibitors, inhibitory antibodies, antibodies directed against growth factors, bifunctional molecules consisting of a growth factor and a cytotoxin, bifunctional molecules consisting of an antibody and a cytotoxin); cholesterol-lowering agents; vasodilating agents; and agents which interfere with endogenous vasoactive mechanisms. 
     It should be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps without exceeding the scope of the disclosure. This may include, to the extent that it is appropriate, the use of any of the features of one example embodiment being used in other embodiments. The disclosure&#39;s scope is, of course, defined in the language in which the appended claims are expressed.