Left atrial appendage implant

Abstract

An implant for occluding a left atrial appendage may comprise an expandable framework including a first framework portion and a second framework portion, the expandable framework configured to shift along a longitudinal axis between a collapsed configuration and an expanded configuration. The second framework portion may be disposed radially inward of the first framework portion in the collapsed configuration. The expandable framework includes a proximal hub and a distal hub. The first framework portion may be fixedly attached to the proximal hub and the distal hub. The second framework portion may be fixedly attached to the proximal hub and the distal hub.

Description

Technical Field

[0001] The present disclosure generally relates to medical devices, and more particularly to medical devices adapted for use in percutaneous medical procedures including implantation into the left atrial appendage (LAA) of the heart.

Background Art

[0002] The left atrial appendage is a small organ attached to the left atrium of the heart. During normal heart function, when the left atrium contracts to push blood into the left ventricle, the left atrial appendage contracts to push blood into the left atrium. The ability of the left atrial appendage to contract helps to improve the filling of the left ventricle and thereby plays a role in maintaining cardiac output. However, in patients suffering from atrial fibrillation, the left atrial appendage may not contract properly or may not empty, causing stagnant blood to pool inside it and leading to the formation of unwanted thrombi in the left atrial appendage.

[0003] Thrombi formed in the left atrial appendage can break free from this area and enter the bloodstream. Thrombi moving through the blood vessels can ultimately block smaller downstream blood vessels and thereby contribute to stroke or heart attack. Clinical studies have shown that the majority of blood clots in patients with atrial fibrillation originate from the left atrial appendage. As a treatment, medical devices have been developed that are arranged to close the left atrial appendage. Each of the known medical devices and methods has specific advantages and disadvantages. There is a continuing need to provide alternative medical devices and introducers, as well as alternative methods for manufacturing and using medical devices and introducers.

Summary of the Invention

[0004] In one example, an implant for occluding the left atrial appendage may comprise an expandable framework including a first framework portion and a second framework portion, the expandable framework being configured to shift along a longitudinal axis between a collapsed configuration and an expanded configuration. The second framework portion may be disposed radially inward of the first framework portion in the collapsed configuration. The expandable framework includes a proximal hub and a distal hub. The first framework portion may be fixedly attached to the proximal hub and the distal hub. The second framework portion may be fixedly attached to the proximal hub and the distal hub.

[0005] In addition to, or alternatively to, any of the examples disclosed herein, the first framework portion includes a first plurality of interconnected struts formed from a first tubular member. In addition to, or alternatively to, any of the examples disclosed herein, the second framework portion includes a second plurality of interconnected struts formed from a second tubular member.

[0006] In addition to, or alternatively to, any of the examples disclosed herein, a portion of the second framework portion is disposed radially outward of the first framework portion in the expanded configuration.

[0007] In addition to, or alternatively to, any of the examples disclosed herein, the first framework portion includes at least one tether member extending radially outward from the first framework portion.

[0008] In addition to, or alternatively to, any of the examples disclosed herein, a portion of the second framework portion disposed radially outward of the first framework portion includes at least one tether member extending radially outward from the second framework portion.

[0009] In addition to, or instead of, any of the examples disclosed herein, a portion of the second framework portion disposed radially outside the first framework portion is disposed adjacent to the proximal shoulder of the first framework portion.

[0010] In addition to, or instead of, any of the examples disclosed herein, a portion of the second framework portion disposed radially outside the first framework portion is disposed proximate to the central portion of the first framework portion.

[0011] In addition to, or instead of, any of the examples disclosed herein, the outer surface of the second framework portion abuts against the inner surface of the first framework portion in an expanded configuration. In addition to, or instead of, any of the examples disclosed herein, the first framework portion includes at least one mooring member extending radially outwardly from the first framework portion.

[0012] In addition to, or instead of, any of the examples disclosed herein, at least one mooring member is longitudinally aligned with the outer surface of the second framework portion that abuts against the inner surface of the first framework portion.

[0013] In addition to, or instead of, any of the examples disclosed herein, the outer surface of the second framework portion abuts against the inner surface of the first framework portion adjacent to the proximal shoulder of the first framework portion.

[0014] In addition to, or instead of, any of the examples disclosed herein, the outer surface of the second framework portion abuts against the inner surface of the first framework portion proximate to the central portion of the first framework portion.

[0015] In addition to, or instead of, any of the examples disclosed herein, the implant may further comprise an occlusion element disposed on an expandable framework. In addition to, or instead of, any of the examples disclosed herein, a system for occluding a left atrial appendage may include a delivery sheath having a lumen and an implant for occluding the left atrial appendage, the implant including an expandable framework having a first framework portion and a second framework portion, the expandable framework configured to shift along a longitudinal axis between a collapsed configuration and an expanded configuration, the second framework portion being disposed radially inward of the first framework portion in the collapsed configuration, the expandable framework including a proximal hub and a distal hub, the first framework portion being fixedly attached to the proximal and distal hubs, the second framework portion being fixedly attached to the proximal and distal hubs, and a core wire releasably securable to the proximal hub of the implant.

[0016] In addition to, or instead of, any of the examples disclosed herein, the first framework portion may include a first plurality of interconnected struts cut from a first tubular member, and the second framework portion may include a second plurality of interconnected struts cut from a second tubular member. The proximal end of the second tubular member is disposed concentrically within the proximal end of the first tubular member.

[0017] In addition to, or instead of, any of the examples disclosed herein, the second framework portion may be more flexible than the first framework portion. In addition to, or instead of, any of the examples disclosed herein, the expandable framework may include at least one tether member extending radially outward therefrom.

[0018] In addition to, or instead of, any of the examples disclosed herein, the expandable framework may be self-biased toward the expanded configuration. In addition to, or instead of, any examples disclosed herein, an implant for occluding the left atrial appendage may comprise an expandable framework including a first framework portion cut from a first tubular member and a second framework portion cut from a second tubular member, the expandable framework being configured to shift along a longitudinal axis between a collapsed configuration and an expanded configuration, and an occlusion element disposed radially outward of the expandable framework. The first tubular member has a first outer diameter, and the second tubular member has a second outer diameter that is smaller than the first outer diameter. The second framework portion is disposed radially inward of the first framework portion in the collapsed configuration. The expandable framework includes a proximal hub and a distal hub. The proximal end of the first framework portion is fixed to the proximal hub, and the distal end of the first framework portion is fixed to the distal hub. The proximal end of the second framework portion is fixed to the proximal hub, and the distal end of the second framework portion is fixed to the distal hub.

[0019] The above summary of some embodiments, aspects, and / or examples is not intended to describe every embodiment or all implementations of the present disclosure. The drawings and detailed description illustrate aspects of these embodiments more specifically.

Brief Description of the Drawings

[0020] The present disclosure may be more fully understood by considering the following detailed description in connection with the accompanying drawings.

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[0021] Aspects of the present disclosure accept various modified forms and alternative forms, examples of which are shown in the drawings and described herein. However, it should be understood that the intention is not to limit the aspects of the present disclosure to the specific embodiments described. Rather, the present disclosure is intended to cover all modifications, equivalents, and alternative forms within its spirit and scope.

Mode for Carrying Out the Invention

[0022] The following description is preferably read with reference to the drawings which are not necessarily to scale, and like reference numerals indicate like elements throughout several views. The detailed description and the drawings are intended to illustrate the present disclosure but not to limit the present disclosure. Those skilled in the art will recognize that the various elements described and / or shown can be arranged in various combinations and configurations without departing from the scope of the present disclosure. The detailed description and the drawings show exemplary embodiments of the present disclosure. However, for clarity and ease of understanding, not all features and / or elements may be shown in each drawing, but it can be understood that the features and / or elements exist nevertheless, unless otherwise specified.

[0023] For the terms defined below, these definitions shall apply unless different definitions are given in the claims or elsewhere in this specification. All numerical values are assumed, whether or not explicitly indicated herein, to be modified by the term "about." The term "about" in the context of a numerical value generally refers to a range of numbers that a person of ordinary skill in the art would consider equivalent (e.g., having the same function or result) to the recited value. In many cases, the term "about" may include numbers rounded to the nearest significant digit. Other uses of the term "about" (e.g., in contexts other than numerical values) may be understood from the context of this specification and may be assumed to have their ordinary customary definitions consistent with the context of this specification, unless otherwise specified.

[0024] The recitation of a numerical range 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 appropriate dimensions, ranges, and / or values for various components, features, and / or specifications are disclosed, one of ordinary skill in the art driven by this disclosure will understand that the desired dimensions, ranges, and / or values may deviate from those explicitly disclosed.

[0025] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in the sense of "and / or" unless the context clearly dictates otherwise. Note that for ease of understanding, certain features of the present disclosure may be described in the singular even though those features may be present in multiple or repeated within the disclosed embodiments. Each instance of a feature includes, and / or may be encompassed by, a singular disclosure unless explicitly stated otherwise. For purposes of simplification and clarity, not all elements of the present disclosure are necessarily shown in each figure or described in detail below. However, it will be understood that the following description applies equally to any and / or all of the components present in more than one, unless explicitly stated otherwise. Further, not all examples of some elements or features are shown in each figure for purposes of clarity.

[0026] Relative terms such as "proximal", "distal", "advancing", "retreating", and variations thereof may generally be considered with respect to the positioning, orientation, and / or movement of various elements relative to a user / operator / manipulator of the device, where "proximal" and "retreating" indicate or refer to being closer to or towards the user, and "distal" and "advancing" indicate or refer to being further from or away from the user. In some cases, the terms "proximal" and "distal" may be arbitrarily assigned for ease of understanding of the present disclosure, in which case it will be readily apparent to those skilled in the art. Other relative terms such as "upstream", "downstream", "inflow", and "outflow" refer to the direction of fluid flow within a lumen such as a body lumen, blood vessel, or within a device. Still other relative terms such as "axial", "circumferential", "longitudinal", "lateral", "radial", and / or variations thereof generally refer to the direction and / or orientation with respect to the central longitudinal axis of the disclosed structure or device.

[0027] The term "range" is to be understood to mean the maximum measured dimension of a stated or specified dimension, unless the range or dimension of the problem is preceded by "minimum" which can be understood to mean the minimum measured value of the stated or specified dimension or is specified as "minimum". For example, "outer range" may be understood to mean the outer dimension, "radial range" may be understood to mean the radial dimension, "longitudinal range" may be understood to mean the longitudinal dimension, and so on. Each example of "range" may be different (e.g., axial direction, longitudinal direction, lateral direction, radial direction, circumferential direction, etc.), and will be apparent to those skilled in the art from the context of the individual usage. Generally, "range" may be considered the largest dimension possible as measured according to the intended use, while "minimum range" may be considered the smallest dimension possible as measured according to the intended use. In some cases, "range" may generally be measured at right angles within a plane and / or cross-section, but may be measured differently, non-limitingly, angularly, radially, circumferentially (e.g., along an arc), etc., as is apparent from the particular context.

[0028] The terms "monolithic" and "unitary" are generally intended to refer to one or more elements made from or consisting of a single structure or base unit / element. Monolithic and / or unitary elements are intended to exclude structures and / or features made by assembling or otherwise joining a plurality of separate structures or elements together.

[0029] The terms "transaortic valve implantation" and "transcatheter aortic valve implantation" may be used interchangeably and may each be referred to using the acronym "TAVI". The terms "transaortic valve replacement" and "transcatheter aortic valve replacement" may be used interchangeably and may each be referred to using the acronym "TAVR".

[0030] References to "embodiments", "some embodiments", "other embodiments", etc. in this specification are to be noted as indicating that the described embodiments may include certain features, structures, or characteristics, but not all embodiments necessarily include the certain features, structures, or characteristics. Further, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in relation to an embodiment, whether explicitly described or not, unless clearly stated otherwise, it would be within the knowledge of those skilled in the art to bring about the particular feature, structure, or characteristic in relation to other embodiments. That is, the various individual elements described below can be combined or arranged with each other to form other additional embodiments or to complement and / or enhance the described embodiments, as would be understood by those skilled in the art, even if not explicitly shown in a particular combination.

[0031] For clarity, throughout the description and / or claims, certain identifying numerical nomenclature (e.g., first, second, third, fourth, etc.) may be used to name and / or distinguish the features of the various descriptions and / or claims. It is to be understood that the numerical nomenclature is not intended to be limiting and is merely illustrative. In some embodiments, for the sake of brevity and clarity, changes and departures from the previously used numerical nomenclature may be made. 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 completely omitted, and / or a different feature may be referred to as the "first" element. The meaning and / or name in each instance will be apparent to those skilled in the art.

[0032] The left atrial appendage is attached to and may communicate with the left atrium of a patient's heart. In some patients, the left atrial appendage may have a complex geometry and / or an irregular surface area. Those skilled in the art will also recognize that the medical devices and methods disclosed herein can be adapted, as needed, to various sizes and shapes of the left atrial appendage. The left atrial appendage may include a substantially longitudinal axis disposed along the depth of the body of the left atrial appendage. The body may include a wall and a small aperture that forms a proximal opening. In some embodiments, the lateral extent of the small aperture and / or the wall may be less than the depth of the body along the longitudinal axis, or the depth of the body may be greater than the lateral extent of the small aperture and / or the wall. In some embodiments, the left atrial appendage may include a tail-like element associated with the distal portion of the body, and that element may project radially or laterally away from the body.

[0033] The following figures show selected components and / or arrangements of an implant for occluding the left atrial appendage, a system for occluding the left atrial appendage, and / or a method of using the implant and / or system. Note that in any given figure, some features may not be shown or may be shown schematically for simplicity. Further details regarding some of the components of the implant and / or system may be shown more particularly in other figures. Although discussed in the context of occluding the left atrial appendage, the implant and / or 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 placement may be used, as appropriate, in other types of surgical procedures. For example, in some instances, the device may be used in non-percutaneous procedures. The devices and methods according to the present disclosure may also be adapted and configured for other uses within anatomical structures.

[0034] Figures 1-2 illustrate selected components and / or arrangements of a system 10 for occluding a left atrial appendage. Note that in any given figure, some features of system 10 may be shown in simplified or schematic form for the sake of clarity. Further details regarding some of the components of system 10 may be shown more particularly in other figures. System 10 may be used to percutaneously deliver and / or position various medical implants (e.g., cardiovascular medical implants, occlusive medical implants, replacement heart valve implants, etc.) at one or more locations within an anatomical structure, including but not limited to the heart, in some embodiments.

[0035] System 10 may include a delivery sheath 40 having a lumen 42 extending from a proximal opening to a distal opening, a core wire 30 slidably disposed within lumen 42, and an implant 100 for occluding the left atrial appendage. Implant 100 may include an expandable framework (e.g., FIG. 3) configured to shift between a collapsed form (e.g., FIG. 1) in which implant 100 is disposed within lumen 42 in a collapsed configuration proximate the distal opening, and an expanded form (e.g., FIG. 2), such that implant 100 and / or the expandable framework 110 are configured to shift between the collapsed and expanded forms when implant 100 is disposed distally of the distal opening of lumen 42 and / or the distal end of delivery sheath 40, and / or when implant 100 is not constrained by delivery sheath 40. In at least some embodiments, the expandable framework 110 may be self-biased toward the expanded form.

[0036] The implant 100 may be disposed at the distal portion of the core wire 30 and / or may be removably fixable. The core wire 30 may be slidably and / or rotatably disposed within the lumen 42 of the delivery sheath 40. In some embodiments, the proximal end of the core wire 30 may extend proximally to the proximal end of the delivery sheath 40 and / or proximal to the proximal opening of the lumen 42 for manual operation by a clinician or practitioner. In some embodiments, the implant 100 may be removably attached, joined, fixed, or otherwise coupled to the distal end of the core wire 30. The core wire 30 may be configured to translate the implant 100 axially relative to the delivery sheath 40 and / or may be capable of translating axially. The delivery sheath 40 and / or the core wire 30 may have a selected level of axial stiffness and / or pushability characteristics while also having a selected level of flexibility that enables navigation through the patient's vasculature.

[0037] Some suitable but non-limiting examples of materials for the system 10, the core wire 30, the delivery sheath 40, and / or the implant 100, etc. are discussed below. It is contemplated that any and / or all of the exemplary implants disclosed herein may be used in accordance with and / or associated with the exemplary system 10 described above.

[0038] The implant 100 may include an expandable framework 110 configured to shift along the longitudinal axis 102 between a collapsed form and an expanded form. In the collapsed form, the expandable framework 110 may be elongated axially and / or compressed radially. In the expanded form, the expandable framework 110 may be shortened axially and / or expanded radially. The expandable framework 110 may include a plurality of interconnected struts that define 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.

[0039] The expandable framework 110 may include a proximal hub 112 and a distal hub 114. In some embodiments, the proximal hub 112 and / or the distal hub 114 may be centered about and / or coaxial with the longitudinal axis 102. The plurality of interconnected struts may be joined together and / or fixedly attached to the proximal hub 112 and / or the distal hub 114. The proximal hub 112 may be configured to releasably connect, secure, and / or attach the implant 100 and / or the expandable framework 110 to the core wire 30. In some embodiments, the proximal hub 112 may include a female thread configured to rotatably and / or threadably engage the male-threaded distal end of the core wire 30. Other configurations for releasably securing the implant 100 to the core wire 30 are contemplated. The expandable framework 110 may include a first framework portion 130 (e.g., FIGS. 3, 5-6) and a second framework portion 150 (e.g., FIGS. 5-6), which are described in more detail herein. As noted above, some features are not shown in all figures for the sake of clarity.

[0040] In some embodiments, the implant 100 may optionally include an occlusion element 120 that is connected to, disposed on, disposed over, disposed around, and / or disposed radially outside at least a portion of an expandable framework 110 and / or a plurality of interconnected struts, as seen in FIG. 4. In some embodiments, the occlusion element 120 may be attached to the proximal hub 112 and / or attached to the expandable framework at the proximal hub 112. In some embodiments, the occlusion element 120 may extend radially outwardly from the proximal hub 112 and / or distally. In some embodiments, the occlusion element 120 may be attached to and / or secured to the expandable framework 110 at multiple discrete locations.

[0041] In some embodiments, the occlusion element 120 may include a membrane, fabric, mesh, tissue element, or another suitable structure. In some embodiments, the occlusion element 120 may be porous. In some embodiments, the occlusion element 120 may be non-porous. In some embodiments, the occlusion element 120 may be permeable or impermeable to other fluids such as blood and / or water. In some embodiments, the occlusion element 120 may be designed, sized, and / or configured to prevent thrombus and / or embolic material from exiting the left atrial appendage and entering the left atrium and / or the patient's bloodstream. In some embodiments, the occlusion element 120 (e.g., a membrane, fabric, or tissue element, etc.) promotes endothelialization after implantation, thereby effectively excluding the target site (e.g., the left atrial appendage, etc.) from the patient's circulatory system. Some suitable but non-limiting examples of materials for the occlusion element 120 are discussed below.

[0042] FIG. 5 schematically shows a selected aspect of the implant 100. It should be noted that the patterns, arrangements, and / or relative positionings of features shown but not explicitly described in this specification are merely exemplary and are not intended to be limiting. In some embodiments, the expandable framework 110 may include a first framework portion 130 and a second framework portion 150. The second framework portion 150 may be disposed radially inward of the first framework portion 130 in a collapsed configuration.

[0043] The first framework portion 130 may include a first plurality of interconnected struts 132 formed and / or cut out from a first tubular member. The first framework portion 130 may have a proximal end 134 and a distal end 136. In some embodiments, the first framework portion 130 and / or the first plurality of interconnected struts 132 may be integrally formed and / or cut out from a single piece of material. In some embodiments, the first framework portion 130 and / or the first plurality of interconnected struts 132 may be integrally formed and / or cut out from a single tubular member and then formed and / or heat set into the desired shape in an expanded configuration. In some embodiments, the first framework portion 130 and / or the first plurality of interconnected struts 132 may be integrally formed and / or cut out from a single flat member or sheet and then wound or formed into a tubular structure and then formed and / or heat set into the desired shape in an expanded configuration. Some exemplary means and / or methods for fabricating and / or forming the first framework portion 130 and / or the first plurality of interconnected struts 132 include laser cutting, machining, punching, stamping, electrical discharge machining (EDM), chemical dissolution, etc. Other means and / or methods are contemplated.

[0044] The second framework portion 150 may include a second plurality of interconnected struts 152 formed and / or cut out from a second tubular member. The second framework portion 150 may have a proximal end 154 and a distal end 156. In some embodiments, the second framework portion 150 and / or the second plurality of interconnected struts 152 may be integrally formed and / or cut out from a single member. In some embodiments, the second framework portion 150 and / or the second plurality of interconnected struts 152 may be integrally formed and / or cut out from a single tubular member and then formed and / or heat set into a desired shape in an expanded form. In some embodiments, the second framework portion 150 and / or the second plurality of interconnected struts 152 may be integrally formed and / or cut out from a single flat member or sheet and then wound or formed into a tubular structure and then formed and / or heat set into a desired shape in an expanded form. Some exemplary means and / or methods for fabricating and / or forming the second framework portion 150 and / or the second plurality of interconnected struts 152 may include laser cutting, machining, punching, stamping, electrical discharge machining (EDM), chemical dissolution, and the like. Other means and / or methods are contemplated.

[0045] As shown in FIG. 5, the second framework portion 150 may be disposed radially inward of the first framework portion 130 in a collapsed form. The first tubular member may have a first outer diameter, and the second tubular member may have a second outer diameter that is smaller than the first outer diameter. In at least some embodiments, the second framework portion 150 may be formed and / or cut out independently of the first framework portion 130 and then the second framework portion 150 may be axially inserted and / or positioned within the first framework portion 130.

[0046] As shown in FIG. 6, the proximal end 134 of the first framework portion 130 may be fixed and / or fixedly attached to the proximal hub 112, and the distal end 136 of the first framework portion 130 may be fixed and / or fixedly attached to the distal hub 114. The proximal end 154 of the second framework portion 150 may be fixed and / or fixedly attached to the proximal hub 112, and the distal end 156 of the second framework portion 150 may be fixed and / or fixedly attached to the distal hub 114. In at least some embodiments, the proximal end 154 of the second framework portion 150 and / or the second tubular member may be concentrically disposed within the proximal end 134 of the first framework portion 130 and / or the first tubular member.

[0047] Alternatively, in some embodiments, the proximal end 134 of the first framework portion 130 may be fixedly attached and / or secured to the proximal hub 112, and the distal end 136 of the first framework portion 130 may be fixedly attached and / or secured to the distal hub 114. The proximal end 154 of the second framework portion 150 may be fixedly attached and / or secured to the proximal hub 112, and the distal end 156 of the second framework portion 150 may be fixedly attached and / or secured to a second distal hub (not shown). The second distal hub may be axially spaced from the distal hub 114. The second distal hub may be disposed within the interior of the first framework portion 130. For example, the distal hub 114 may be at a first distance from the proximal hub 112 in the axial and / or longitudinal direction, and the second distal hub may be at a second distance from the proximal hub 112 in the axial and / or longitudinal direction, and the second distance may be less than the first distance. In some embodiments, the second framework portion 150 may be shorter than the first framework portion 130 in the collapsed configuration and / or the expanded configuration. In some embodiments, a connecting element may extend between the distal hub 114 and the second distal hub. In some embodiments, the connecting element may be a strut, a tether, or other element. In some embodiments, the connecting element may be a coil spring configured to bias the second distal hub toward or away from the distal hub 114. In some embodiments, when the expandable framework 110 is shifted to the expanded configuration, the coil spring may assist in shifting the second framework portion 150 to the expanded configuration by moving the second distal hub away from the distal hub 114 and / or toward the proximal hub 112. Other configurations are contemplated.

[0048] In some embodiments, the expandable framework 110 may be flexible and, in its expanded form, may substantially conform and / or sealingly engage to the shape and / or geometry of the sidewall of the left atrial appendage. In some embodiments, the implant 100 may expand to a size, extent, or shape that is less than the maximum unconstrained extent or different from the maximum unconstrained extent as determined by the surrounding tissue and / or sidewall of the left atrial appendage. In some embodiments, reducing the thickness of various elements of the expandable framework 110 may increase the flexibility and extensibility of the expandable framework 110 and / or the implant 100, thereby enabling the expandable framework 110 and / or the implant 100 to conform to the surrounding tissue rather than the tissue conforming to the unexpanded framework 110 and / or the implant 100.

[0049] In some embodiments, the first framework portion 130 may be more rigid and / or less flexible than the second framework portion 150. In some embodiments, the second framework portion 150 may be more flexible than the first framework portion 130. In some embodiments, the first framework portion 130 may be configured to shape and / or stretch the tissue of the left atrial appendage such that the sidewall of the left atrial appendage substantially conforms to the outer profile of the first framework portion 130. As will be appreciated by those skilled in the art, anatomical features can vary in size and / or shape. In some embodiments, the left atrial appendage may have an irregular (e.g., elongated and / or oval) cross-sectional shape. In such embodiments, the left atrial appendage may not perfectly match the outer profile of the first framework portion 130. For example, most of the sidewall of the left atrial appendage may conform to the outer profile of the first framework portion 130, but a portion of the sidewall of the left atrial appendage may be spaced from and / or remain spaced from the first framework portion 130 due to the irregular cross-sectional shape of the left atrial appendage, thus resulting in an incomplete and / or leaking seal between the implant 100 and the left atrial appendage.

[0050] In some embodiments, as shown in FIG. 7, in an expanded configuration, a portion 160 of the second framework portion 150 may be configured and / or heat set such that it is disposed radially outward of the first framework portion 130. The second framework portion 150 may be configured to fill any gap between the first framework portion 130 and the sidewall of the left atrial appendage, thereby improving the seal between the implant 100 and the left atrial appendage. In some embodiments, the expandable framework 110 may include at least one anchoring member 170 extending radially outward therefrom. In some embodiments, the first framework portion 130 may include at least one anchoring member 170 extending radially outward from the first framework portion 130. In some embodiments, the first framework portion 130 may include at least one anchoring member 170 extending radially outward from the first framework portion 130 proximate the proximal shoulder 140. In some embodiments, the first framework portion 130 may include at least one anchoring member 170 extending radially outward from the first framework portion 130 proximate the central portion of the first framework portion 130. In some embodiments, at least one anchoring member 170 may be configured to engage the sidewall of the body of the left atrial appendage. In some embodiments, at least one anchoring member 170 may be formed as a J-shaped hook extending in a proximal direction with respect to the longitudinal axis 102 of the expandable framework 110 and / or having a free end directed in a proximal direction. Other configurations are contemplated. In some embodiments, one, some, and / or all of the at least one anchoring member 170, if present, may extend through the occlusion element 120 as shown in FIG. 4. In some embodiments, a portion 160 of the second framework portion 150 disposed radially outward of the first framework portion 130 may be disposed adjacent to the proximal shoulder 140 of the first framework portion 130 as seen in FIG. 7.

[0051] As shown in FIG. 8, in an alternative configuration, in some embodiments, the outer surface of the second framework portion 150 may abut the inner surface of the first framework portion 130 in an expanded configuration. In some embodiments, the outer surface of the second framework portion 150 may abut the inner surface of the first framework portion 130 adjacent to the proximal shoulder 140 of the first framework portion 130 in an expanded configuration. In some embodiments, the second framework portion 150 may be configured to support the first framework portion 130 at and / or adjacent to the proximal shoulder 140. In some embodiments, the second framework portion 150 is configured to increase the radially outward force exerted on the side wall of the left atrial appendage by the first framework portion 130 at and / or adjacent to the proximal shoulder 140 to improve the shaping and / or conforming of the side wall of the left atrial appendage to the outer shape of the first framework portion 130. In some embodiments, the first framework portion 130 may include at least one tethering member 170 extending radially outward from the first framework portion 130 proximate to the proximal shoulder 140. In some embodiments, the first framework portion 130 may include at least one tethering member 170 extending radially outward from the first framework portion 130 proximate to the central portion of the first framework portion 130. In some embodiments, at least one tethering member 170 may be configured to engage the side wall of the body of the left atrial appendage. In some embodiments, at least one tethering member 170 may be formed as a J-shaped hook extending in a proximal direction and / or having a free end directed in a proximal direction with respect to the longitudinal axis 102 of the expandable framework 110. Other configurations are contemplated. In some embodiments, one, some, and / or all of the at least one tethering member 170 may extend through the occlusion element 120, if present, as shown in FIG. 4. In some embodiments, at least one tethering member 170 may be longitudinally aligned with the outer surface of the second framework portion 150 abutting the inner surface of the first framework portion 130.In some embodiments, at least one mooring member 170 may be longitudinally offset from the outer surface of a second framework portion 150 that abuts an inner surface of the first framework portion 130.

[0052] As shown in FIG. 9, in another alternative embodiment, in some embodiments, the second framework portion 150 may be configured and / or heat set in an expanded form such that a portion 160 of the second framework portion 150 is disposed radially outward of the first framework portion 130. The second framework portion 150 may be configured to fill any gap between the first framework portion 130 and the side wall of the left atrial appendage, thereby improving the seal between the implant 100 and the left atrial appendage. In some embodiments, the expandable framework 110 may include at least one tethering member 170 extending radially outward therefrom. In some embodiments, the second framework portion 150 may include at least one tethering member 170 extending radially outward from the second framework portion 150. In some embodiments, the second framework portion 150 may include at least one tethering member 170 extending radially outward from the second framework portion 150 proximate the proximal shoulder 140. In some embodiments, the second framework portion 150 may include at least one tethering member 170 extending radially outward from the second framework portion 150 proximate the central portion 142 of the first framework portion 130. In some embodiments, at least one tethering member 170 may be configured to engage the side wall of the body of the left atrial appendage. In some embodiments, at least one tethering member 170 may be formed as a J-shaped hook extending in a proximal direction with respect to the longitudinal axis 102 of the expandable framework 110 and / or having a free end directed in a proximal direction. Other configurations are contemplated. In some embodiments, one, some, and / or all of the at least one tethering member 170 may extend through the occlusion element 120, if present, as shown in FIG. 4. In some embodiments, a portion 160 of the second framework portion 150 disposed radially outward of the first framework portion 130 may be disposed proximate the central portion 142 of the first framework portion 130, as seen in FIG. 9.In some embodiments, the second framework portion 150 may be configured to improve the fixation of the implant 100 within the left atrial appendage by increasing the engagement of the tethering member with the sidewall of the left atrial appendage.

[0053] As can be seen in FIG. 10, in another alternative configuration, in some embodiments, the outer surface of the second framework portion 150 may abut against the inner surface of the first framework portion 130 in an expanded configuration. In some embodiments, the outer surface of the second framework portion 150 may abut against the inner surface of the first framework portion 130 proximate to the central portion 142 of the first framework portion 130 in an expanded configuration. In some embodiments, the second framework portion 150 may be configured to support the first framework portion 130 proximate to and / or adjacent to the central portion 142 of the first framework portion 130. In some embodiments, the second framework portion 150 is configured to increase the radially outward force exerted on the side wall of the left atrial appendage by the first framework portion 130 proximate to and / or adjacent to the central portion 142 of the first framework 130 in order to improve the shaping and / or conforming of the side wall of the left atrial appendage to the outer shape of the first framework portion 130 and / or to improve the engagement of the tethering member with the side wall of the left atrial appendage. In some embodiments, the first framework portion 130 may include at least one tethering member 170 extending radially outward from the first framework portion 130 proximate to the central portion 142 of the first framework portion 130. In some embodiments, at least one tethering member 170 may be configured to engage the side wall of the body of the left atrial appendage. In some embodiments, at least one tethering member 170 may be formed as a J-shaped hook extending in a proximal direction with respect to the longitudinal axis 102 of the expandable framework 110 and / or having a free end directed in a proximal direction. Other configurations are contemplated. In some embodiments, one, some, and / or all of the at least one tethering member 170 may extend through the occlusion element 120, if present, as shown in FIG. 4. In some embodiments, at least one tethering member 170 may be longitudinally aligned with the outer surface of the second framework portion 150 that abuts against the inner surface of the first framework portion 130, as seen in FIG. 10.In some embodiments, the second framework portion 150 may be configured to improve the fixation of the implant 100 within the left atrial appendage by increasing the engagement of the tethering member with the side wall of the left atrial appendage.

[0054] A method for occluding the left atrial appendage may include advancing an implant 100 into the left atrial appendage. For example, the implant 100 may be advanced into the left atrial appendage within the lumen 42 of the delivery sheath 40 in a collapsed form. The method includes positioning an expandable framework 110 within the left atrial appendage from the delivery sheath 40. The method further includes expanding and / or shifting the expandable framework 110 from a collapsed form to an expanded form within the left atrial appendage. In the expanded form, the expandable framework 110 may be biased to contact, engage, and / or be tethered to the side wall of the body of the left atrial appendage. In at least some embodiments, the implant 100 and / or the expandable framework 110 may extend across the ostium of the left atrial appendage. In some embodiments, the implant 100 and / or the expandable framework 110 may completely traverse the ostium of the left atrial appendage, thereby effectively excluding the left atrial appendage from the patient's circulatory system.

[0055] Once the requirements for positioning the implant 100 within the left atrial appendage are met, the core wire 30 can be detached from the implant 100, thereby leaving the implant 100 positioned in and / or within the left atrial appendage. In some embodiments, detaching the core wire 30 from the implant 100 may include rotating the male-threaded distal end of the core wire 30 relative to the implant 100 and / or the proximal hub 112 to disengage the core wire 30 from the implant 100.

[0056] In some embodiments, the delivery sheath 40 and / or the core wire 30 may include a keying structure configured to prevent rotation of the core wire 30 relative to the proximal hub 112. In such embodiments, the keying structure is disengaged before rotating the core wire 30 relative to the implant 100 and / or the proximal hub 112. When the keying structure is engaged, rotation of the core wire 30 can be transmitted to the implant 100 and / or the expandable framework 110. In some embodiments, rotation of the implant 100 and / or the expandable framework 110 may facilitate positioning and / or orientation of the implant 100 and / or the expandable framework 110 relative to the left atrial appendage, for example, relative to asymmetric and / or irregular fenestrations and / or the left atrial appendage. Other configurations, purposes, and / or results are also contemplated.

[0057] The various components of the system (and / or other elements disclosed herein) and the materials that may be used for the various components of the system disclosed herein may include those commonly associated with medical devices and / or systems. For simplicity, the following discussion refers to the system. However, this discussion applies, but is not limited to, implants, delivery sheaths, core wires, expandable frameworks, occlusion elements, etc., and / or other elements, members, components, or devices disclosed herein of those elements or components, etc., and this is not intended to limit the devices and methods described herein.

[0058] In some embodiments, the system and / or its components may be made of metal, metal alloy, polymer (some examples of which are disclosed below), metal-polymer composite, ceramic, combinations thereof, etc., or other suitable materials.

[0059] Some examples of suitable metals and alloys include stainless steels such as 444V, 444L, and 314LV stainless steel; mild steel; nickel-titanium alloys such as linear elastic and / or superelastic 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, etc.), nickel-copper alloys (e.g., UNS:N04400 such as MONEL® 400, NICKELVAC™ 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R44035 such as MP35-N™), nickel-molybdenum alloys (e.g., UNS:N100665 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, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R44003 such as ELGILOY®, PHYNOX®); platinum-reinforced stainless steel; titanium; combinations thereof; equivalents; or any other suitable material.

[0060] As suggested herein, within the family of commercially available nickel-titanium alloys or nitinol alloys, there is a category referred to as "linear elastic" or "non-superelastic", which may be chemically similar to conventional shape memory and superelastic species but exhibit distinct useful mechanical properties. Linear elastic and / or non-superelastic nitinol can be distinguished from superelastic nitinol in that in its stress / strain curve, it does not exhibit a substantial "superelastic plateau" or "flag region" as shown by superelastic nitinol. Instead, in linear elastic and / or non-superelastic nitinol, as the recoverable strain increases, the stress increases in a relationship that is substantially linear, or somewhat but not necessarily completely linear, up to the onset of plastic deformation, or at least more linear than the superelastic plateau and / or flag region that can be seen in superelastic nitinol. Thus, for the purposes of the present disclosure, linear elastic and / or non-superelastic nitinol may also be referred to as "substantially" linear elastic and / or non-superelastic nitinol.

[0061] Also, in some cases, linear elastic and / or non-superelastic nitinol can be distinguished from superelastic nitinol in that it can tolerate up to about 2 - 5% strain while remaining substantially elastic (e.g., prior to plastic deformation), whereas superelastic nitinol can tolerate up to about 8% strain prior to plastic deformation. Both of these materials can be distinguished from other linear elastic materials, such as stainless steel, which can only tolerate about 0.2 - 0.44 percent strain prior to plastic deformation (which can also be distinguished based on its composition).

[0062] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy is an alloy that does not exhibit a martensite / austenite phase change detectable by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) over a wide temperature range. For example, in some embodiments, in the linear elastic and / or non-superelastic nickel-titanium alloy, there may be no martensite / austenite phase change detectable by DSC and DMTA analysis in the range of about -60 °C to about 120 °C. Thus, the mechanical bending properties of such materials may generally be inert to the influence of temperature over this very wide temperature range. In some embodiments, the mechanical bending properties of the linear elastic and / or non-superelastic nickel-titanium alloy at ambient temperature or room temperature are substantially the same as the mechanical properties at body temperature, for example, in that they do not exhibit a superelastic plateau and / or flag region. In other words, over a wide temperature range, the linear elastic and / or non-superelastic nickel-titanium alloy maintains its linear elastic and / or non-superelastic characteristics and / or properties.

[0063] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy may be in the range of about 50 to about 60 weight percent nickel, with the balance being essentially titanium. In some embodiments, the composition is in the range of about 54 to about 57 weight percent nickel. An example of a suitable nickel-titanium alloy is the FHP-NT alloy commercially available from Furukawa Techno-Material Co., Ltd., located in Kanagawa Prefecture, Japan. Other suitable materials include ULTANIUM (trademark) (available from Neo-Metrics) and GUM METAL (registered trademark) (available from Toyota). In some other embodiments, a superelastic alloy, such as superelastic nitinol, may be used to achieve the desired properties.

[0064] In at least some embodiments, some or all of the systems and / or other elements disclosed herein may also be doped with a radiopaque material, made from a radiopaque material, or otherwise include a radiopaque material. A radiopaque material is understood to be a material that can generate a relatively bright image with a fluoroscopic screen or another imaging technique during a medical procedure. This relatively bright image assists the user in determining the position of the systems and / or other elements disclosed herein. Some examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radiopaque fillers, etc. Additionally, other radiopaque marker bands and / or coils may also be incorporated into the design of the systems and / or other elements disclosed herein to achieve the same result.

[0065] In some embodiments, some degree of magnetic resonance imaging (MRI) compatibility is imparted to the systems and / or other elements disclosed herein. For example, the system and / or its components or parts may be made of a material that does not substantially distort the image and does not generate substantial artifacts (i.e., gaps within the image). For example, certain ferromagnetic materials may not be suitable as they may have the potential to generate artifacts in the MRI image. The system or a part thereof may be made of a material that can be imaged by an MRI machine. Some materials exhibiting these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R44003 such as ELGILOY®, PHYNOX®), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R44035 such as MP35-N™), nitinol, etc., and others.

[0066] In some embodiments, the systems and / or other elements disclosed herein may be made of or include a polymer or other suitable material. Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block ester, polyurethane (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether ester (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester copolymers (e.g., other polyester elastomers such as butylene / poly(alkylene ether) phthalate and / or HYTREL® available from DuPont), polyamide (e.g., DURETHAN® available from Bayer or CRISTAMID™ available from Elf Atochem), elastomeric polyamide, block polyamide / ether, polyether block amide (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), MARLEX® high density polyethylene, MARLEX® low density polyethylene, linear low density polyethylene (e.g., REXELL™), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon 12 (EMS AmericanThose available from Grilon such as GRILAMID®), perfluoro(propyl vinyl ether) (PFA), ethyl vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, ionomer, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites thereof, etc. may be mentioned. In some embodiments, the sheath may be mixed with a liquid crystal polymer (LCP). For example, the mixture may contain up to about 6% LCP.

[0067] In some embodiments, the systems and / or other elements disclosed herein may include a fabric material disposed on or within the structure. The fabric material may be composed of a biocompatible material such as a polymer material or a biological material adapted to promote in-growth within the tissue. In some embodiments, the fabric material may include a bioabsorbable material. Some examples of suitable fabric materials include, but are not limited to, polyolefin materials such as polyethylene glycol (PEG), nylon, polytetrafluoroethylene (PTFE, ePTFE), polyethylene, polypropylene, polyester, polyurethane, and / or blends or combinations thereof.

[0068] In some embodiments, the systems and / or other elements disclosed herein may include and / or be formed from a textile material. Some examples of suitable textile materials can include synthetic yarns that can be flat, shaped, twisted, textured, pre-shrunk, or non-shrinking. Synthetic biocompatible yarns suitable for use in the present disclosure include, but are not limited to, polyesters including polyethylene terephthalate (PET) polyester, polypropylene, polyethylene, polyurethane, polyolefin, polyvinyl, polymethyl acetate, polyamide, naphthalene dicarboxylate derivatives, natural silk, and polytetrafluoroethylene. Further, at least one of the synthetic yarns may be a metal yarn or a glass or ceramic yarn or fiber. Useful metal yarns include those made from or containing stainless steel, platinum, gold, titanium, tantalum, or Ni-Co-Cr based alloys. The yarn may further include carbon, glass, or ceramic fibers. Desirably, the yarn is made from a thermoplastic material including, but not limited to, polyester, polypropylene, polyethylene, polyurethane, polynaphthalene, polytetrafluoroethylene, etc. The yarn may be multifilament, monofilament, or of the staple type. The type and denier of the yarn selected may be chosen to form a biocompatible and implantable prosthesis, more specifically, a vascular structure having desirable properties.

[0069] In some embodiments, the systems and / or other elements disclosed herein may contain and / or be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents include antithrombotic agents (such as heparin, heparin derivatives, urokinase, and PPack (dextrorphan proline arginine chloromethyl ketone)); antiproliferative agents (such as enoxaparin, angiotensin, monoclonal antibodies that can block smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory agents (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine); antitumor / antiproliferative / antimitotic agents (such as paclitaxel, 5-fluorouracil, cisplatin, vincblastine, vincristine, epothilone, endostatin, angiostatin, and thymidine kinase inhibitors); anesthetics (such as lidocaine, bupivacaine, and ropivacaine); anticoagulants (such as D-Phe-Pro-Arg chloromethyl ketone, RGD peptide-containing compounds, heparin, antithrombin compounds, platelet receptor antagonists, antithrombin antibodies, antiplatelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick antiplatelet peptides); vasocyte growth promoters (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional activators, and translational promoters); vasocyte growth inhibitors (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional repressors, translational repressors, replication inhibitors, inhibitory antibodies, antibodies against growth factors, bifunctional molecules consisting of growth factors and cytotoxins, bifunctional molecules consisting of antibodies and cytotoxins); cholesterol-lowering agents; vasodilators; and agents that interfere with the endogenous vasomotor mechanism.

[0070] It should be understood that the present disclosure is merely exemplary in many respects. Without exceeding the scope of the present disclosure, changes can be made in detail, particularly with respect to the shape, size, and arrangement of steps. This may include the use of any of the features of one exemplary embodiment in other embodiments within an appropriate scope. The scope of the present disclosure is, of course, defined by the language in which the appended claims are expressed.

Claims

1. An implant for occluding a left atrial appendage, comprising an expandable framework including a first framework portion and a second framework portion, said expandable framework including an expandable framework configured to shift along a longitudinal axis between a collapsed form and an expanded form, said first framework portion including a first plurality of interconnected struts formed from a first tubular member, said second framework portion including a second plurality of interconnected struts formed from a second tubular member, said second framework portion being disposed radially inward of said first framework portion in said collapsed form, a portion of said second framework portion being disposed radially outward of said first framework portion in said expanded form, said portion of said second framework portion disposed radially outward of said first framework portion including at least one tether member extending radially outward from said second framework portion, said expandable framework including a proximal hub and a distal hub, said first framework portion being fixedly attached to said proximal hub and said distal hub, said second framework portion being fixedly attached to said proximal hub and said distal hub, the implant.

2. The implant according to claim 1, wherein said first framework portion includes at least one tether member extending radially outward from said first framework portion.

3. The implant according to claim 1, wherein said portion of said second framework portion disposed radially outward of said first framework portion is disposed adjacent to a proximal shoulder of said first framework portion.

4. The implant according to claim 1, wherein a part of the second framework portion disposed radially outside the first framework portion is disposed close to the central portion of the first framework portion.

5. The implant according to claim 1, wherein the second framework portion is more flexible than the first framework portion.

6. The implant according to claim 1, further comprising an occlusion element disposed on the expandable framework.

7. A system for occluding the left atrial appendage, comprising: A delivery sheath having a lumen; The implant according to any one of claims 1 to 6; A core wire releasably fixable to the proximal hub of the implant; and a system comprising the same.

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