Patent Publication Number: US-2023142374-A1

Title: Twisted tip soft tissue anchors

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority of U.S. Provisional Application No. 63/277,406 filed Nov. 9, 2021, the entire disclosure of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The disclosure relates generally to medical devices and more particularly to occlusive implants 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. Soft tissue anchors for medical devices often are formed from wire barbs that have little flexibility in design. Barb height and angle are usually the main design parameters. These types of anchors may not fully retain and/or anchor the medical device or implant in all clinical situations, possibly leading to device embolization, shifting, etc. There is an ongoing need to provide alternative medical devices and methods for manufacturing and using medical devices. 
     SUMMARY 
     In one example, an occlusive implant may comprise an expandable framework having a central longitudinal axis extending from a proximal end to a distal end, the expandable framework being configured to shift between a collapsed configuration and an expanded configuration. The expandable framework includes a plurality of anchor members extending radially outward from the expandable framework in the expanded configuration, each anchor member including at least one base portion fixedly secured to the expandable framework and a plurality of anchor tips extending from each base portion. Each base portion extends longitudinally along the expandable framework. 
     In addition or alternatively to any example described herein, each of the plurality of anchor members includes at least two twisted filaments. 
     In addition or alternatively to any example described herein, each of the at least two twisted filaments forms one of the plurality of anchor tips. 
     In addition or alternatively to any example described herein, each of the plurality of anchor members includes at least three twisted filaments. 
     In addition or alternatively to any example described herein, each of the at least three twisted filaments forms one of the plurality of anchor tips. 
     In addition or alternatively to any example described herein, each anchor tip of the plurality of anchor tips is configured to penetrate tissue. 
     In addition or alternatively to any example described herein, the plurality of anchor tips extending from each base portion collectively form a tissue shelf configured to limit penetration of the plurality of anchor tips into tissue. 
     In addition or alternatively to any example described herein, each anchor member includes a pedestal portion disposed between each base portion and the plurality of anchor tips extending from each base portion such that the pedestal portion extends outward from the base portion and the plurality of anchor tips extends outward from the pedestal portion. 
     In addition or alternatively to any example described herein, each anchor member includes a bridge portion connecting two base portions fixedly secured to the expandable framework and a plurality of anchor tips extending from each base portion. 
     In addition or alternatively to any example described herein, a method of making an occlusive implant may comprise forming an expandable framework having a central longitudinal axis extending from a proximal end to a distal end, the expandable framework being configured to shift between a collapsed configuration and an expanded configuration; forming a plurality of anchor members, wherein each anchor member includes at least one base portion and a plurality of anchor tips extending from each base portion; and fixedly attaching each base portion to the expandable framework. Each anchor member extends radially outward from the expandable framework in the expanded configuration. Each base portion extends longitudinally along the expandable framework. 
     In addition or alternatively to any example described herein, forming the plurality of anchor members includes twisting at least two filaments together to form each anchor member, each filament having a first end and a second end. 
     In addition or alternatively to any example described herein, forming the plurality of anchor members includes separating and/or splaying apart the first ends of the at least two filaments to form the plurality of anchor tips of a first base portion of the at least one base portion and separating and/or splaying apart the second ends of the at least two filaments to form the plurality of anchor tips of a second base portion of the at least one base portion, wherein portions of the at least two filaments that remain twisted together form each base portion and a bridge portion connecting each anchor member of the plurality of anchor members. 
     In addition or alternatively to any example described herein, each base portion is formed from twisting the first ends of the at least two filaments together and the second ends of the at least two filaments each form one of the plurality of anchor tips. 
     In addition or alternatively to any example described herein, forming the plurality of anchor members includes twisting at least three filaments together to form each anchor member, each filament having a first end and a second end. 
     In addition or alternatively to any example described herein, each base portion is formed from twisting the first ends of the at least three filaments together and the second ends of the at least three filaments each form one of the plurality of anchor tips. 
     In addition or alternatively to any example described herein, a method of making an occlusive implant may comprise forming an expandable framework having a central longitudinal axis extending from a proximal end to a distal end, the expandable framework being configured to shift between a collapsed configuration and an expanded configuration; twisting at least two first filaments together to form a first anchor member including at least one base portion and a plurality of first anchor tips extending from each base portion of the first anchor member; twisting at least two second filaments together to form a second anchor member including at least one base portion and a plurality of second anchor tips extending from each base portion of the second anchor member; fixedly attaching the first anchor member to the expandable framework such that each base portion of the first anchor member extends longitudinally along the expandable framework; and fixedly attaching the second anchor member to the expandable framework such that each base portion of the second anchor member extends longitudinally along the expandable framework. 
     In addition or alternatively to any example described herein, each of the at least two first filaments and each of the at least two second filaments are formed from a metallic material. 
     In addition or alternatively to any example described herein, the plurality of first anchor tips extending from each base portion of the first anchor member is spaced apart from each other in the expanded configuration. 
     In addition or alternatively to any example described herein, the plurality of second anchor tips extending from each base portion of the second anchor member is spaced apart from each other in the expanded configuration. 
     In addition or alternatively to any example described herein, the plurality of first anchor tips collectively forms a first tissue shelf configured to limit penetration of the plurality of first anchor tips into tissue. The plurality of second anchor tips collectively forms a second tissue shelf configured to limit penetration of the plurality of second anchor tips into tissue. 
     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 more particularly exemplify aspects of these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure may be more completely understood in consideration of the following detailed description in connection with the accompanying drawings, in which: 
         FIGS.  1 - 2    schematically illustrate prior art medical devices having soft tissue anchors formed from a wire barb; 
         FIGS.  3 - 3 A  illustrate penetration of the prior art soft tissue anchors into tissue; 
         FIGS.  4 - 5    are side views of an occlusive implant system; 
         FIG.  6    illustrates selected aspects of an occlusive implant; 
         FIG.  7    is a perspective view illustrating an example anchor member according to the disclosure; 
         FIGS.  8 - 8 A  illustrate penetration of the example anchor member into tissue; 
         FIGS.  9 - 9 A  illustrate penetration of the example anchor member into tissue; and 
         FIG.  10    is a perspective view illustrating an alternative configuration of an anchor member according to the disclosure. 
     
    
    
     While aspects of the disclosure are amenable to various modifications and alternative forms, examples are shown in the drawings and described herein. 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 disclosure shall cover all modifications, equivalents, and alternatives falling within the spirit and scope thereof. 
     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 present 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 exemplary aspects of the 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 embodiment(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, all elements of the present disclosure are not 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 the 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 the 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 the greatest possible dimension measured according to the intended usage, while a “minimum extent” may be considered the 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 use 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 left atrial appendage may be attached to and in fluid communication with a left atrium of a patient&#39;s heart. In some patients, the left atrial appendage may have a complex geometry and/or irregular surface area. Those of skill in the art will also recognize that the medical devices and methods disclosed herein may be adapted for various sizes and shapes of the left atrial appendage, as necessary. The left atrial appendage may include a generally longitudinal axis arranged along a depth of a main body of the left atrial appendage. The main body may include a wall and an ostium forming a proximal mouth. In some embodiments, a lateral extent of the ostium and/or the wall may be smaller or less than a depth of the main body along the longitudinal axis, or a depth of the main body may be greater than a lateral extent of the ostium and/or the wall. In some embodiments, the left atrial appendage may include a tail-like element associated with a distal portion of the main body, which element may protrude radially or laterally away from the main body. 
       FIG.  1    illustrates an occlusive implant  10  having a plurality of wire barbs  12  as anchoring elements. The plurality of wire barbs  12  have a single anchoring tip  14  at the ends of the plurality of wire barbs  12 .  FIG.  2    illustrates an occlusive implant  20  having a plurality of wire barbs  22  as anchoring elements. The plurality of wire barbs  22  have a single anchoring tip  24  at the ends of the plurality of wire barbs  22 . Anchoring provided by the wire barbs may not be consistent in all clinical situations.  FIG.  3    illustrates an example of the depth of penetration P 1  of the plurality of wire barbs  12 / 22  into tissue  50  and the extension distance D 1  of the outermost extent of the plurality of wire barbs  12 / 22  from the occlusive implant  10 / 20 . In some situations, the thickness of the tissue  50  may vary. For example, the left atrial appendage may have varying tissue thickness about its circumference and/or length. As such, in some situations, the thickness of the tissue  50  may be insufficient for the depth of penetration of the plurality of wire barbs  12 / 22  to avoid completely passing through the tissue  50  and creating a puncture, as seen in  FIG.  3 A . Depth of penetration may be desirable for anchoring but may also be a detriment to repositioning and/or recapture of the occlusive implant. Additionally, completely penetrating the tissue  50  is undesirable for several reasons, including but not limited to leakage through the puncture and potential damage to adjacent tissues and/or body structures. 
     The following figures illustrate selected components and/or arrangements of an occlusive implant, an occlusive implant system, and/or methods of making and/or using the occlusive implant and/or the occlusive implant 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 occlusive 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 occlusive implant 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. Additionally, while some elements may be shown and/or described in the singular, the figures and/or description shall apply to each instance of said element(s) present in the occlusive implant. 
     The figures illustrate selected components and/or arrangements of an occlusive implant system  100 , shown schematically in  FIGS.  4 - 5    for example. In some embodiments, the occlusive implant system  100  may include a delivery device that can be used for percutaneous delivery of an occlusive implant to an area of interest in the anatomy, such as a left atrial appendage. This, however, is not intended to be limiting as the occlusive implant system  100  and/or the delivery device may also be used for other interventions. 
     The occlusive implant system  100  may include a sheath  140  having a lumen  142  extending from a proximal opening to a distal opening, a core wire  130  slidably disposed within the lumen  142 , and an occlusive implant  200  having an expandable framework  210  configure to shift between a collapsed configuration (e.g.,  FIG.  4   ), wherein the occlusive implant  200  is disposed within an implant containment area of the sheath  140  proximate a distal end of the sheath  140  and/or the distal opening in the collapsed configuration, and an expanded configuration (e.g.,  FIG.  5   ), wherein the occlusive implant  200  and/or the expandable framework  210  is configured to shift between the collapsed configuration and the expanded configuration when the occlusive implant  200  is disposed distal of the distal end of the sheath  140  and/or the distal opening, and/or when the occlusive implant  200  is distal of and/or outside of the implant containment area of the sheath  140 . The occlusive implant  200  may be disposed at and/or releasably connected to a distal portion of the core wire  130 . The core wire  130  may be slidably and/or rotatably disposed within the lumen  142  of the sheath  140  and/or the implant containment area of the sheath  140 . In some embodiments, a proximal end of the core wire  130  may extend proximally of a proximal end of the sheath  140  and/or the proximal opening of the lumen  142  for manual manipulation by a clinician or practitioner. In some embodiments, the occlusive implant  200  may be removably attached, joined, or otherwise connected to the distal end of the core wire  130 . The core wire  130  may be configured to and/or may be capable of axially translating the occlusive implant  200  relative to the sheath  140  and/or the implant containment area of the sheath  140 . In one example, the core wire  130  may be advanced distally while the sheath  140  is held in a constant position. In another example, the core wire  130  may be advanced distally while the sheath  140  is retracted proximally. In yet another example, the core wire  130  may be held in a constant position while the sheath  140  is retracted proximally relative to the core wire  130  and/or the occlusive implant  200 . Other configurations are also contemplated. The sheath  140  and/or the core wire  130  may have a selected level of axial stiffness and/or pushability characteristics while also having a selected level of flexibility to permit navigation through the patient&#39;s vasculature. Some suitable, but non-limiting, examples of materials for the occlusive implant system  100 , the core wire  130 , the sheath  140 , and/or the occlusive implant  200 , etc. are discussed below. 
       FIG.  6    illustrates selected aspects of an occlusive implant  200 . In some embodiments, the occlusive implant  200  comprising the expandable framework  210  may be configured to shift axially and/or radially along a central longitudinal axis between the collapsed configuration and the expanded configuration. The expandable framework  210  may comprise a plurality of interconnected struts defining a plurality of cells. In some embodiments, the plurality of cells may be a plurality of closed cells. In some embodiments, the plurality of cells may be a plurality of open cells. In some embodiments, the plurality of cells may include a plurality of open cells and a plurality of closed cells in various combinations and/or arrangements. The expandable framework  210  may be compliant and substantially conform to and/or be in sealing engagement with the shape and/or geometry of an ostium and/or a lateral wall of a left atrial appendage in the expanded configuration. In some embodiments, the occlusive implant  200  may expand to a size, extent, or shape less than or different from a maximum unconstrained extent, as determined by the surrounding tissue, the ostium, and/or the lateral wall of the left atrial appendage. In some embodiments, reducing a thickness of various elements of the expandable framework  210  may increase the flexibility and compliance of the expandable framework  210  and/or the occlusive implant  200 , thereby permitting the expandable framework  210  and/or the occlusive implant  200  to conform to the tissue around it, rather than forcing the tissue to conform to the expandable framework  210  and/or the occlusive implant  200 . 
     The expandable framework  210  may include a proximal end and a distal end. In some embodiments, the expandable framework  210  may include a proximal hub configured to releasably attach, join, couple, engage, or otherwise connect to a distal end of the core wire  130 . In some embodiments, the proximal hub of the expandable framework  210  may include a threaded insert coupled thereto. In some embodiments, the threaded insert may be configured to and/or adapted to couple with, join to, mate with, or otherwise engage a threaded member disposed at the distal end of the core wire  130 . Other means of releasably coupling and/or engaging the proximal hub of the expandable framework  210  to the distal end of the core wire  130  are also contemplated. As noted herein, some features are not shown in every figure to improve clarity. 
     In some embodiments, the expandable framework  210  and/or the plurality of interconnected struts may be formed and/or cut from a tubular member. In some embodiments, the expandable framework  210  and/or the plurality of interconnected struts may be integrally formed and/or cut from a flat member or sheet, and then rolled or formed into a tubular structure and subsequently formed and/or heat set to the desired shape in the expanded configuration. Some exemplary means and/or methods of making and/or forming the expandable framework  210  and/or the plurality of interconnected struts include laser cutting, machining, punching, stamping, electro discharge machining (EDM), chemical dissolution, etc. Other means and/or methods are also contemplated. Alternatively, in some embodiments, the expandable framework  210  and/or the plurality of interconnected struts may be braided, woven, and/or otherwise intertwined from and/or using one or more individual filaments. Other configurations are also contemplated. 
     In some embodiments, the occlusive implant  200  and/or the expandable framework  210  may include a plurality of anchor members  240  projecting radially outward from the expandable framework  210  and/or the plurality of interconnected struts in the expanded configuration. In some embodiments, each anchor member of the plurality of anchor members  240  may include at least one base portion  242  fixedly secured to the expandable framework  210  and/or the plurality of interconnected struts. In some embodiments, each anchor member of the plurality of anchor members  240  may include at least one base portion  242  directly and/or fixedly attached to and/or at the expandable framework  210  and/or the plurality of interconnected struts. In some embodiments, the plurality of anchor members  240  may be configured to engage with the lateral wall of the left atrial appendage. Other configurations are also contemplated. Additional details regarding the plurality of anchor members  240  is discussed below. 
     In some embodiments, the occlusive implant  200  may optionally include an occlusive element  220  connected to, disposed on, disposed over, disposed about, or covering at least a portion of the expandable framework  210  and/or the plurality of interconnected struts. In some embodiments, the occlusive element  220  may be connected to, disposed on, disposed over, disposed about, or cover at least a portion of an outer (or outwardly facing) surface of the expandable framework  210  and/or the plurality of interconnected struts. In some embodiments, the occlusive element  220  may be attached to the proximal hub and/or may be attached to the expandable framework  210  at the proximal hub. In some embodiments, the occlusive element  220  may extend radially outward from and/or may extend distally from the proximal hub. In some embodiments, the occlusive element  220  may be attached and/or secured to the expandable framework  210  at a plurality of discrete locations. In some embodiments, one of, some of, and/or all of the plurality of anchor members  240  may extend through an occlusive element  220 , where present. 
     In some embodiments, the occlusive element  220  may include a membrane, a fabric, a mesh, a tissue element, or another suitable construction. In some embodiments, the occlusive element  220  may be porous. In some embodiments, the occlusive element  220  may be non-porous. In some embodiments, the occlusive element  220  may be permeable to selected gases and/or fluids. In some embodiments, the occlusive element  220  may be substantially impermeable to selected gases and/or fluids, such as blood, water, etc. In some embodiments, the occlusive element  220  may be designed, sized, and/or configured to prevent thrombus and/or embolic material from passing out of the left atrial appendage into the left atrium and/or the patient&#39;s bloodstream. In some embodiments, the occlusive element  220  may be configured to promote endothelization after implantation, thereby effectively removing the target site (e.g., the left atrial appendage, etc.) from the patient&#39;s circulatory system. Some suitable, but non-limiting, examples of materials for the occlusive element  220  are discussed below. 
       FIG.  7    illustrates an example embodiment of one of the plurality of anchor members  240  associated with the occlusive implant  200 . As will be understood, the discussion herein related to the plurality of anchor members  240  may be applied equally to and/or may be used in place of each of the plurality of anchor members  240  present in the occlusive implant  200 . References to the expandable framework  210  and/or elements thereof discussed herein, while not expressly shown, may be understood to be as discussed herein (with respect to  FIGS.  4 - 6   , for example). 
     As discussed herein, the expandable framework  210  may include a plurality of anchor members  240  extending radially outward from the expandable framework  210  in the expanded configuration. Each anchor member of the plurality of anchor members  240  may include at least one base portion  242  fixedly secured and/or fixedly attached to the expandable framework  210  and/or the plurality of interconnected struts. In some embodiments, each anchor member of the plurality of anchor members  240  is formed separately from the expandable framework  210  and later fixedly secured and/or fixedly attached to the expandable framework  210 . 
     Each anchor member of the plurality of anchor members  240  may include a pedestal portion  243  and a plurality of anchor tips  246  extending from each base portion of the at least one base portion  242 . In some embodiments, the pedestal portion  243  may be disposed between each base portion of the at least one base portion  242  and the plurality of anchor tips  246  extending from each base portion. In some embodiments, the pedestal portion  243  may extend outward from each base portion of the at least one base portion  242  and the plurality of anchor tips  246  may extend outward from the pedestal portion  243 . In some embodiments, the pedestal portion  243  may be integrally and/or monolithically formed with the at least one base portion  242  and/or the plurality of anchor tips  246 . Each anchor tip of the plurality of anchor tips  246  may be configured to penetrate tissue. In some embodiments, each anchor tip of the plurality of anchor tips  246  may include a rounded tip. In some embodiments, each anchor tip of the plurality of anchor tips  246  may include a flattened tip. In some embodiments, each anchor tip of the plurality of anchor tips  246  may include a sharpened tip. Other configurations, including various combinations thereof, are also contemplated. 
     In some embodiments, the plurality of anchor tips  246  extending from each base portion of the at least one base portion  242  collectively form a tissue shelf  250  configured to limit the depth of penetration P 2  of the plurality of anchor tips  246  into the tissue  50 , as seen in  FIGS.  8 - 9 A , and the extension distance D 1  of the outermost extent of the plurality of anchor tips  246  from the expandable framework  210  seen in  FIGS.  8 - 8 A . In an alternative configuration, the pedestal portion  243 A may be configured to deflect and/or “lay down” against the expandable framework  210 , such that the extension distance D 2  of the outermost extent of the plurality of anchor tips  246  from the expandable framework  210  is reduced, as seen in  FIGS.  9 - 9 A . 
     In some embodiments, the tissue shelf  250  may be formed from a laterally extending portion of each of the plurality of anchor tips  246 . For example, each of the plurality of anchor tips  246  may include a flattened portion oriented generally perpendicular to the pedestal portion  243  and/or a distalmost tip portion of each of the plurality of anchor tips  246 . By providing the plurality of anchor tips  246  (e.g., more than the one wire barb  12 / 22  shown in  FIG.  3   ) on each base member of the at least one base portion  242  and/or on each pedestal portion, anchoring is improved over a single wire barb while limiting penetration into the tissue  50  may improve the ability to reposition and/or recapture the occlusive implant  200  while limiting and/or without causing unnecessary and/or unintended damage to the tissue  50 . Returning to  FIGS.  8 - 8 A , anchoring may be improved because the pedestal portion  243  “lifts” the tissue  50  relative to the expandable framework  210 , thereby increasing engagement force between the plurality of anchor tips  246  and the tissue  50  and/or against the tissue shelf  250  which then transfers down the pedestal portion  243  to the at least one base portion  242  and the expandable framework  210 . 
     In at least some embodiments, each base portion of the at least one base portion  242  may extend longitudinally along the expandable framework  210 . Each base portion of the at least one base portion  242  may extend longitudinally along an outer surface of the expandable framework  210 . In some embodiments, each base portion of the at least one base portion  242  may extend longitudinally along the expandable framework  210  toward a distal end of the expandable framework  210 . 
     Returning to  FIG.  7   , in some embodiments, the at least one base portion  242  of each anchor member may include more than one base portion. In at least some embodiments, each anchor member of the plurality of anchor members  240  may include a bridge portion  248  connecting two base portions fixedly secured to the expandable framework  210  and a plurality of anchor tips  246  extending from each base portion of the two base portions. Each base portion of the two base portions may be fixedly secured to the expandable framework  210 . While not expressly illustrated, in some embodiments, the at least one base portion  242  of each anchor member may include more than two base portions. In some embodiments, each anchor member of the plurality of anchor members  240  may include a bridge portion  248  connecting the more than two base portions. In some embodiments, the bridge portion  248  may be fixedly secured to the expandable framework  210  in addition to or in alternative to each base portion of the at least one base portion  242 . Other configurations are also contemplated. 
     Each anchor member of the plurality of anchor members  240  may include and/or may be formed from at least two twisted filaments  244 . In some embodiments, each of the at least two twisted filaments  244  forms one of the plurality of anchor tips  246 . In some embodiments, each of the at least two twisted filaments  244  forms exactly one anchor tip of the plurality of anchor tips  246 . For example, in some embodiments, each base portion of an anchor member having exactly two twisted filaments  244  will have exactly two anchor tips extending therefrom. Other configurations are also contemplated. 
     In some embodiments, the at least two twisted filaments  244  may form each base portion of the at least one base portion  242 . For example, in embodiments of an anchor member having two base portions and the bridge portion  248 , the at least two twisted filaments  244  form two base portions, the bridge portion  248  connecting the two base portions, and a plurality of anchor tips  246  extending from each base portion. 
     In some embodiments, forming the plurality of anchor members  240  may include twisting at least two filaments  244  together to form each anchor member, wherein each filament  244  has a first end and a second end. In some embodiments, forming the plurality of anchor members  240  may include separating and/or splaying apart the first ends of the at least two filaments  244  to form the plurality of anchor tips  246  of a first base portion of the at least one base portion  242  (and/or of the two base portions) and separating and/or splaying apart the second ends of the at least two filaments  244  to form the plurality of anchor tips  246  of a second base portion of the at least one base portion  242  (and/or of the two base portions), wherein portions of the at least two filaments  244  that remain twisted together form each base portion and the bridge portion  248  of each anchor member of the plurality of anchor members  240 . 
     In some embodiments, each anchor member of the plurality of anchor members  240  may include and/or may be formed from at least three twisted filaments  244 . In some embodiments, each of the at least three twisted filaments  244  forms one of the plurality of anchor tips  246 . In some embodiments, each of the at least three twisted filaments  244  forms exactly one anchor tip of the plurality of anchor tips  246 . For example, in some embodiments, each base portion of an anchor member having exactly three twisted filaments  244  will have exactly three anchor tips extending therefrom. Other configurations are also contemplated. 
     In some embodiments, the at least three twisted filaments  244  may form each base portion of the at least one base portion  242 . For example, in embodiments of an anchor member having two base portions and the bridge portion  248 , the at least three twisted filaments  244  form two base portions, the bridge portion  248  connecting the two base portions, and a plurality of anchor tips  246  extending from each base portion. 
     In some embodiments, forming the plurality of anchor members  240  may include twisting at least three filaments  244  together to form each anchor member, wherein each filament  244  has a first end and a second end. In some embodiments, forming the plurality of anchor members  240  may include separating and/or splaying apart the first ends of the at least three filaments  244  to form the plurality of anchor tips  246  of a first base portion of the at least one base portion  242  (and/or of the two base portions) and separating and/or splaying apart the second ends of the at least three filaments  244  to form the plurality of anchor tips  246  of a second base portion of the at least one base portion  242  (and/or of the two base portions), wherein portions of the at least three filaments  244  that remain twisted together form each base portion and the bridge portion  248  of each anchor member of the plurality of anchor members  240 . 
       FIG.  10    illustrates an alternative configuration of an anchor member of the plurality of anchor members  240 . Similar to  FIG.  7   , each anchor member of the plurality of anchor members  240  may include at least one base portion  242  fixedly secured and/or fixedly attached to the expandable framework  210  and/or the plurality of interconnected struts. In some embodiments, each anchor member of the plurality of anchor members  240  is formed separately from the expandable framework  210  and later fixedly secured and/or fixedly attached to the expandable framework  210 . 
     Each anchor member of the plurality of anchor members  240  may include a pedestal portion  243  and a plurality of anchor tips  246  extending from each base portion of the at least one base portion  242 . In some embodiments, the pedestal portion  243  may extend from each base portion of the at least one base portion  242  and the plurality of anchor tips  246  may extend from the pedestal portion  243 . Each anchor tip of the plurality of anchor tips  246  may be configured to penetrate tissue. In some embodiments, each anchor tip of the plurality of anchor tips  246  may include a rounded tip. In some embodiments, each anchor tip of the plurality of anchor tips  246  may include a flattened tip. In some embodiments, each anchor tip of the plurality of anchor tips  246  may include a sharpened tip. Other configurations, including various combinations thereof, are also contemplated. 
     In some embodiments, the plurality of anchor tips  246  extending from each base portion of the at least one base portion  242  collectively form a tissue shelf  250  configured to limit the depth of penetration P 2  of the plurality of anchor tips  246  into the tissue  50  and the extension distance D 1  of the outermost extent of the plurality of anchor tips  246  from the expandable framework  210  (e.g.,  FIGS.  8 - 8 A ). In some embodiments, the tissue shelf  250  may be formed from a laterally extending portion of each of the plurality of anchor tips  246 . For example, each of the plurality of anchor tips  246  may include a flattened portion oriented generally perpendicular to the pedestal portion  243  and/or a distalmost tip portion of each of the plurality of anchor tips  246 . By providing the plurality of anchor tips  246  (e.g., more than the one wire barb  12 / 22  shown in  FIG.  3   ) on each base member of the at least one base portion  242  and/or on each pedestal portion, anchoring is improved over a single wire barb while limiting penetration into the tissue  50  may improve the ability to reposition and/or recapture the occlusive implant  200  while limiting and/or without causing unnecessary and/or unintended damage to the tissue  50 . Similar to above (e.g.,  FIGS.  8 - 8 A ), anchoring may be improved because the pedestal portion  243  “lifts” the tissue  50  relative to the expandable framework  210 , thereby increasing engagement force between the plurality of anchor tips  246  and the tissue  50  and/or against the tissue shelf  250  which then transfers down the pedestal portion  243  to the at least one base portion  242  and the expandable framework  210 . 
     In at least some embodiments, each base portion of the at least one base portion  242  may extend longitudinally along the expandable framework  210 . Each base portion of the at least one base portion  242  may extend longitudinally along an outer surface of the expandable framework  210 . In some embodiments, each base portion of the at least one base portion  242  may extend longitudinally along the expandable framework  210  toward a distal end of the expandable framework  210 . Returning to  FIG.  10   , in some embodiments, the at least one base portion  242  of each anchor member may include exactly one base portion. 
     Each anchor member of the plurality of anchor members  240  may include and/or may be formed from at least two twisted filaments  244 . In some embodiments, each of the at least two twisted filaments  244  forms one of the plurality of anchor tips  246 . In some embodiments, each of the at least two twisted filaments  244  forms exactly one anchor tip of the plurality of anchor tips  246 . For example, in some embodiments, each base portion of an anchor member having exactly two twisted filaments  244  will have exactly two anchor tips extending therefrom. Other configurations are also contemplated. 
     In some embodiments, the at least two twisted filaments  244  may form each base portion of the at least one base portion  242 . For example, in embodiments of an anchor member having exactly one base portion, the at least two twisted filaments  244  form exactly one base portion and a plurality of anchor tips  246  extending from the exactly one base portion. 
     In some embodiments, forming the plurality of anchor members  240  may include twisting at least two filaments  244  together to form each anchor member, wherein each filament  244  has a first end and a second end. In some embodiments, each base portion of the at least one base portion  242  is formed from twisting the first ends of the at least two filaments  244  together and the second ends of the at least two filaments  244  each form one of the plurality of anchor tips  246 . For example, in some embodiments, forming the plurality of anchor members  240  may include separating and/or splaying apart the second ends of the at least two filaments  244  to form the plurality of anchor tips  246  of exactly one base portion, wherein the first ends and/or portions of the at least two filaments  244  that remain twisted together form the exactly one base portion of each anchor member of the plurality of anchor members  240 . 
     In some embodiments, each anchor member of the plurality of anchor members  240  may include and/or may be formed from at least three twisted filaments  244 . In some embodiments, each of the at least three twisted filaments  244  forms one of the plurality of anchor tips  246 . In some embodiments, each of the at least three twisted filaments  244  forms exactly one anchor tip of the plurality of anchor tips  246 . For example, in some embodiments, each base portion of an anchor member having exactly three twisted filaments  244  will have exactly three anchor tips extending therefrom. Other configurations are also contemplated. 
     In some embodiments, the at least three twisted filaments  244  may form each base portion of the at least one base portion  242 . For example, in embodiments of an anchor member having exactly one base portion, the at least three twisted filaments  244  form exactly one base portion and a plurality of anchor tips  246  extending from the exactly one base portion. 
     In some embodiments, forming the plurality of anchor members  240  may include twisting at least three filaments  244  together to form each anchor member, wherein each filament  244  has a first end and a second end. In some embodiments, each base portion of the at least one base portion  242  is formed from twisting the first ends of the at least three filaments  244  together and the second ends of the at least three filaments  244  each form one of the plurality of anchor tips  246 . For example, in some embodiments, forming the plurality of anchor members  240  may include separating and/or splaying apart the second ends of the at least three filaments  244  to form the plurality of anchor tips  246  of exactly one base portion, wherein the first ends and/or portions of the at least three filaments  244  that remain twisted together form the exactly one base portion of each anchor member of the plurality of anchor members  240 . 
     In some embodiments, a method of making the occlusive implant  200  may include forming the expandable framework  210  having a central longitudinal axis extending from a proximal end to a distal end. The expandable framework  210  may be configured to shift between a collapsed configuration and an expanded configuration. In some embodiments, the expandable framework  210  may be biased toward and/or to the expanded configuration. In some embodiments, the expandable framework  210  may be self-biased toward and/or to the expanded configuration. In some embodiments, the expandable framework  210  may be mechanically expandable from the collapsed configuration toward and/or to the expanded configuration. In some embodiments, the expandable framework  210  may be balloon expandable from the collapsed configuration toward and/or to the expanded configuration. In some embodiments, the expandable framework  210  may be configured to self-expand from the collapsed configuration toward and/or to the expanded configuration. Other configurations are also contemplated. 
     The method may include forming a plurality of anchor members  240 , wherein each anchor member includes at least one base portion  242  and a plurality of anchor tips  246  extending from each base portion of the at least one base portion  242 . In some embodiments, each anchor member may include a pedestal portion  243  extending from each base portion of the at least one base portion  242  and a plurality of anchor tips  246  extending from the pedestal portion  243 . In some embodiments, the pedestal portion  243  may be integrally and/or monolithically formed with the at least one base portion  242  and/or the plurality of anchor tips  246 . 
     In some embodiments, the method and/or forming the plurality of anchor members  240  may include twisting at least two filaments  244  together to form each anchor member of the plurality of anchor members  240 , wherein each filament  244  has a first end and a second end. In some embodiments, the method may include twisting at least two first filaments together to form a first anchor member including at least one base portion and a plurality of first anchor tips extending from each base portion of the first anchor member. In some embodiments, the method may include twisting at least two first filaments together to form a first anchor member including at least one base portion, a first pedestal portion, and a plurality of first anchor tips extending from the first pedestal portion. In some embodiments, the method may include twisting at least two second filaments together to form a second anchor member including at least one base portion and a plurality of second anchor tips extending from each base portion of the second anchor member. In some embodiments, the method may include twisting at least two second filaments together to form a second anchor member including at least one base portion, a second pedestal portion, and a plurality of second anchor tips extending from the second pedestal portion. Additional filaments may be twisted together to form additional anchor members as necessary. In some embodiments, each of the at least two first filaments and each of the at least two second filaments may be formed from a metallic material. In some embodiments, each of the at least two first filaments and each of the at least two second filaments may be formed from a polymeric material. Other configurations are also contemplated. 
     In some embodiments, the method and/or forming the plurality of anchor members  240  may include twisting at least three filaments  244  together to form each anchor member of the plurality of anchor members  240 , wherein each filament  244  has a first end and a second end. In some embodiments, the method may include twisting at least three first filaments together to form a first anchor member including at least one base portion and a plurality of first anchor tips extending from each base portion of the first anchor member. In some embodiments, the method may include twisting at least three first filaments together to form a first anchor member including at least one base portion, a first pedestal portion, and a plurality of first anchor tips extending from the first pedestal portion. In some embodiments, the method may include twisting at least three second filaments together to form a second anchor member including at least one base portion and a plurality of second anchor tips extending from each base portion of the second anchor member. In some embodiments, the method may include twisting at least three second filaments together to form a second anchor member including at least one base portion, a second pedestal portion, and a plurality of second anchor tips extending from the second pedestal portion. Additional filaments may be twisted together to form additional anchor members as necessary. In some embodiments, each of the at least three first filaments and each of the at least three second filaments may be formed from a metallic material. In some embodiments, each of the at least three first filaments and each of the at least three second filaments may be formed from a polymeric material. Other configurations are also contemplated. 
     In some embodiments, the plurality of first anchor tips extending from each base portion of the at least one base portion and/or the first pedestal portion of the first anchor member may be spaced apart from each other in the expanded configuration. In some embodiments, the plurality of first anchor tips may collectively form a first tissue shelf configured to limit penetration of the plurality of first anchor tips into tissue. In some embodiments, the plurality of second anchor tips extending from each base portion of the at least one base portion and/or the second pedestal portion of the second anchor member may be spaced apart from each other in the expanded configuration. In some embodiments, the plurality of second anchor tips may collectively form a second tissue shelf configured to limit penetration of the plurality of second anchor tips into tissue. Additional anchor members, where present, may be configured in a similar manner. 
     In some embodiments, each base portion of the at least one base portion  242  and/or each pedestal portion may be fixedly secured together after twisting the at least two filaments  244  together to form each anchor member of the plurality of anchor members  240 . In some embodiments, the at least two filaments  244  of each base portion of the at least one base portion  242  and/or of each pedestal portion may be welded, brazed, soldered, bonded, or otherwise fixedly attached to each other after twisting the at least two filaments  244  together to form each anchor member of the plurality of anchor members  240 . In some embodiments, each base portion of the at least one base portion  242  and/or each pedestal portion may be fixedly secured together after twisting the at least three filaments  244  together to form each anchor member of the plurality of anchor members  240 . In some embodiments, the at least three filaments  244  of each base portion of the at least one base portion  242  and/or of each pedestal portion may be welded, brazed, soldered, bonded, or otherwise fixedly attached to each other after twisting the at least three filaments  244  together to form each anchor member of the plurality of anchor members  240 . 
     In some embodiments, the method may include fixedly attaching each anchor member of the plurality of anchor members  240  to the expandable framework  210 . In some embodiments, the method may include fixedly attaching each base portion of the at least one base portion  242  to the expandable framework  210 . In some embodiments, the method may include fixedly attaching each base portion of the at least one base portion  242  directly to the expandable framework  210 . In some embodiments, each base portion of the at least one base portion  242  may be welded to the expandable framework  210 . In some embodiments, each base portion of the at least one base portion  242  may be adhesively bonded to the expandable framework  210 . In some embodiments, each base portion of the at least one base portion  242  may be brazed or soldered to the expandable framework  210 . In some embodiments, each base portion of the at least one base portion  242  may be fixedly attached to the expandable framework  210  using mechanical fasteners. In some embodiments, each base portion of the at least one base portion may be integrally and/or monolithically formed with the expandable framework  210 . In at least some embodiments, the pedestal portion  243  is not directly attached to and/or is not in direct contact with the expandable framework  210 . Other configurations are also contemplated. 
     In some embodiments, the method may include fixedly attaching the first anchor member of the plurality of anchor members  240  and/or each base portion of the at least one base portion  242  of the first anchor member to the expandable framework  210 . In some embodiments, the method may include fixedly attaching the first anchor member of the plurality of anchor members  240  and/or each base portion of the at least one base portion  242  of the first anchor member directly to the expandable framework  210 . In some embodiments, the method may include fixedly attaching the first anchor member of the plurality of anchor members  240  and/or each base portion of the at least one base portion  242  of the first anchor member to the expandable framework  210  such that each base portion of the at least one base portion  242  of the first anchor member of the plurality of anchor members  240  extends longitudinally along the expandable framework  210  and/or is in direct contact with the expandable framework  210 . 
     In some embodiments, the method may include fixedly attaching the second anchor member of the plurality of anchor members  240  and/or each base portion of the at least one base portion  242  of the second anchor member to the expandable framework  210 . In some embodiments, the method may include fixedly attaching the second anchor member of the plurality of anchor members  240  and/or each base portion of the at least one base portion  242  of the second anchor member directly to the expandable framework  210 . In some embodiments, the method may include fixedly attaching the second anchor member of the plurality of anchor members  240  and/or each base portion of the at least one base portion  242  of the second anchor member to the expandable framework  210  such that each base portion of the at least one base portion  242  of the second anchor member of the plurality of anchor members  240  extends longitudinally along the expandable framework  210  and/or is in direct contact with the expandable framework  210 . 
     The materials that can be used for the various components of the system (and/or other elements disclosed herein) and the various components thereof disclosed herein may include those commonly associated with medical devices and/or systems. For simplicity purposes, the following discussion refers to the 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 occlusive implant, the expandable framework, the occlusive element, the anchor member(s), etc. and/or elements or components thereof. 
     In some embodiments, the 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 metals and metal alloys include stainless steel, such as 444V, 444L, and 314LV 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: R44035 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: R44003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; combinations thereof; and the like; or any other suitable material. 
     As alluded to herein, within the family of commercially available nickel-titanium or nitinol alloys, is a category designated “linear elastic” or “non-super-elastic” which, although may be similar in chemistry to conventional shape memory and super-elastic varieties, may exhibit distinct and useful mechanical properties. Linear elastic and/or non-super-elastic nitinol may be distinguished from super-elastic nitinol in that the linear elastic and/or non-super-elastic nitinol does not display a substantial “super-elastic plateau” or “flag region” in its stress/strain curve like super-elastic nitinol does. Instead, in the linear elastic and/or non-super-elastic nitinol, as recoverable strain increases, the stress continues to increase in a substantially linear, or a somewhat, but not necessarily entirely linear relationship until plastic deformation begins or at least in a relationship that is more linear than the super-elastic plateau and/or flag region that may be seen with super-elastic nitinol. Thus, for the purposes of this disclosure linear elastic and/or non-super-elastic nitinol may also be termed “substantially” linear elastic and/or non-super-elastic nitinol. 
     In some cases, linear elastic and/or non-super-elastic nitinol may also be distinguishable from super-elastic nitinol in that linear elastic and/or non-super-elastic nitinol may accept up to about 2-5% strain while remaining substantially elastic (e.g., before plastically deforming) whereas super-elastic nitinol may accept up to about 8% strain before plastically deforming. Both of these materials can be distinguished from other linear elastic materials such as stainless steel (that can also be distinguished based on its composition), which may accept only about 0.2 to 0.44 percent strain before plastically deforming. 
     In some embodiments, the linear elastic and/or non-super-elastic nickel-titanium alloy is an alloy that does not show any martensite/austenite phase changes that are detectable by differential scanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA) analysis over a large temperature range. For example, in some embodiments, there may be no martensite/austenite phase changes detectable by DSC and DMTA analysis in the range of about −60 degrees Celsius (° C.) to about 120° C. in the linear elastic and/or non-super-elastic nickel-titanium alloy. The mechanical bending properties of such material may therefore be generally inert to the effect of temperature over this very broad range of temperature. In some embodiments, the mechanical bending properties of the linear elastic and/or non-super-elastic nickel-titanium alloy at ambient or room temperature are substantially the same as the mechanical properties at body temperature, for example, in that they do not display a super-elastic plateau and/or flag region. In other words, across a broad temperature range, the linear elastic and/or non-super-elastic nickel-titanium alloy maintains its linear elastic and/or non-super-elastic characteristics and/or properties. 
     In some embodiments, the 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 super-elastic alloy, for example a super-elastic nitinol can be used to achieve desired properties. 
     In at least some embodiments, portions or all of the system and/or other elements disclosed herein 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 a user in determining the location of the system and/or other elements disclosed herein. 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 system and/or other elements disclosed herein to achieve the same result. 
     In some embodiments, a degree of Magnetic Resonance Imaging (MRI) compatibility is imparted into the system and/or other elements disclosed herein. For example, the system and/or components or portions thereof may be made of a material that does not substantially distort the image and create substantial artifacts (e.g., gaps in the image). Certain ferromagnetic materials, for example, may not be suitable because they may create artifacts in an MRI image. The system or portions thereof, may also be made from a material that the MRI machine can image. Some materials that exhibit these characteristics include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R44003 such as ELGILOY®, PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R44035 such as MP35-N® and the like), nitinol, and the like, and others. 
     In some embodiments, the system and/or other elements disclosed herein may be made from or include a polymer 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, ionomers, 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. 
     In some embodiments, the 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 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 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 chloromethyl ketone)); 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 ketone, 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.