Implantable medical device with sealing that conforms to irregular openings

Abstract

The implantable medical device includes an expandable frame expandable between a collapsed configuration for delivery and an expanded configuration for deployment, the expandable frame including a periphery defined by the expandable frame, a covering spanning at least a portion of the expandable frame, and an expandable element secured to the periphery and adapted to seal against irregular body orifices.

Description

[Technical Field]

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

[0002] The left atrial appendage is a small organ connected to the left atrium of the heart. During normal cardiac function, when the left atrium contracts to pump blood into the left ventricle, the left atrial appendage also contracts to pump blood into the left atrium. The ability of the left atrial appendage to contract contributes to improved filling of the left ventricle, thereby contributing to maintaining cardiac output. However, in patients with atrial fibrillation, the left atrial appendage is unable to contract or empty properly, leading to the accumulation of stagnant blood within it and the potential for unwanted blood clots to form within the left atrial appendage.

[0003] Thrombi formed within the left atrial appendage can break away from this site and enter the bloodstream. Thrombi that migrate within the vessel can eventually occlude smaller peripheral blood vessels, thereby contributing to a stroke or myocardial infarction. 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 that are placed to close the left atrial appendage. Of the known medical devices and methods, each has certain advantages and disadvantages. There continues to be a need to provide alternative medical devices, as well as alternative methods for manufacturing and using medical devices. Summary of the Invention

[0004] The present disclosure provides alternatives for the design, materials, manufacturing methods, and uses of medical devices, including, by way of example, an implantable medical device. The implantable medical device includes an expandable frame expandable between a collapsed configuration for delivery and an expanded configuration for deployment, the expandable frame including a periphery defined by the expandable frame. A covering spans at least a portion of the expandable frame. An expandable element is secured to the periphery and adapted to seal against an irregular body orifice.

[0005] Alternatively or additionally, the irregular opening may include the ostium of the patient's left atrial appendage (LAA). Alternatively or additionally, the expandable element may include a plurality of bag filters arranged around its periphery.

[0006] Alternatively or additionally, each of the plurality of bag filters may have an open end and a closed end, and each of the plurality of bag filters may be arranged along the periphery with the open end facing in one direction and the closed end facing in the opposite direction.

[0007] Alternatively or additionally, each of the plurality of bag filters may have an open end and a closed end, and each of the plurality of bag filters may be arranged in an alternating manner around the periphery such that the open end of one bag filter is positioned adjacent to the closed end of an adjacent bag filter.

[0008] Alternatively or additionally, at least some of the plurality of bag filters may have two open ends and may include one-way valves that restrict blood flow through the open ends. Alternatively or additionally, at least some of the plurality of bag filters may include a coagulant disposed within the bag filter.

[0009] Alternatively or additionally, the expandable element may include a corrugated tri-layer element extending around the periphery, the corrugated tri-layer element including an inner layer, an outer layer, and a middle layer with alternating connections to the inner layer and outer layer.

[0010] Alternatively or additionally, the corrugated tri-layer element may include a coagulant. Alternatively or additionally, the expandable element may comprise an omnidirectional valved mesh. Alternatively or additionally, the implantable medical device may include a LAAC (left atrial appendage closure) device.

[0011] Another example can be found in a LAAC (left atrial appendage closure) device adapted to fit inside an irregular ostium of a patient's LAA (left atrial appendage). The LAAC device includes an expandable frame expandable between a collapsed configuration for delivery and an expanded configuration for deployment, the expandable frame including a periphery defined by the expandable frame. A covering spans at least a portion of the expandable frame. The expandable element is adapted to seal the irregular ostium of the patient's LAA (left atrial appendage).

[0012] Alternatively or additionally, the expandable element may include a clotting agent. Alternatively or additionally, the expandable element may include a swellable member. Alternatively or additionally, the expandable element may include multiple bag filters.

[0013] Another example can be found in a left atrial appendage closure (LAAC) device adapted to fit within an irregular ostium of a patient's left atrial appendage (LAA). The LAAC device includes an expandable frame expandable between a collapsed configuration for delivery and an expanded configuration for deployment, the expandable frame including a periphery defined by the expandable frame. A covering spans at least a portion of the expandable frame. A plurality of bag filters are disposed along the periphery.

[0014] Alternatively or additionally, each of the plurality of bag filters may have an open end and a closed end, and each of the plurality of bag filters may be arranged along the periphery with the open end facing in one direction and the closed end facing in the opposite direction.

[0015] Alternatively or additionally, each of the plurality of bag filters may have an open end and a closed end, and each of the plurality of bag filters may be arranged in an alternating manner around the periphery such that the open end of one bag filter is positioned adjacent to the closed end of an adjacent bag filter.

[0016] Alternatively or additionally, at least some of the plurality of bag filters may have two open ends and may include one-way valves that restrict blood flow through the open ends. Alternatively or additionally, at least some of the plurality of bag filters may include a coagulant disposed within the bag filter.

[0017] The foregoing summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present invention. The figures and detailed description that follow more particularly exemplify these embodiments.

[0018] The present invention may be more fully understood upon consideration of the following detailed description of various embodiments of the invention in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0019] [Figure 1] Partial cross-section of the left atrial appendage (LAA). [Figure 2] 1 is a perspective view of an exemplary left atrial appendage closure (LAAC) device with its cover removed. [Figure 3] 3 is a perspective view of the exemplary left atrial appendage closure (LAAC) device of FIG. 2 including a coating. [Figure 4] 1 is a schematic cross-sectional view of an exemplary left atrial appendage closure (LAAC) device. [Figure 5] 1 is a schematic enlarged view of a plurality of filter bags. [Figure 6]Schematic diagram of an expansion element that utilizes the filter bag of Figure 5 and can be combined with the LAAC device. [Figure 7] Schematic diagram of an expansion element that utilizes the filter bag of Figure 5 and can be combined with the LAAC device. [Figure 8] 1 is a schematic diagram of an exemplary LAAC device with an expansion element, shown positioned within the LAA. [Figure 9] Schematic of an exemplary LAAC device with a corrugated, three-layered expansion element. [Figure 10] 10 is a schematic diagram showing the exemplary LAAC device of FIG. 9 placed within an irregular opening. [Figure 11] Schematic diagram of an exemplary valved mesh. [Figure 12A] 1 is a diagram of an exemplary membrane material that may be used as a coating for the LAAC device described herein. [Figure 12B] 1 is a diagram of an exemplary membrane material that may be used as a coating for the LAAC device described herein. [Figure 12C] 1 is a diagram of an exemplary membrane material that may be used as a coating for the LAAC device described herein. DETAILED DESCRIPTION OF THE INVENTION

[0020] While the invention is susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It is to be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. Rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

[0021] The following description should be read with reference to the drawings, which are not necessarily to scale, and in which like reference numerals refer to like elements throughout the several views. The detailed description and drawings are intended to illustrate, not limit, the disclosure. Those skilled in the art will recognize that the various elements described and / or illustrated can be arranged in various combinations and configurations without departing from the scope of the disclosure. The detailed description and drawings illustrate exemplary embodiments of the disclosure. However, for clarity and ease of understanding, not all features and / or elements are shown in every drawing, but it can be understood that, unless otherwise specified, the features and / or elements are present regardless.

[0022] 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 numerical values ​​herein, whether explicitly stated or not, are assumed to be modified by the term "about." The term "about" generally refers to a range of numerical values ​​that one of ordinary skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term "about" may include numbers that are rounded to the nearest significant figure.

[0023] The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). 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 used in its sense including "and / or" unless the content clearly dictates otherwise.

[0024] 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 used in its sense, including "and / or," unless the content clearly dictates otherwise. For ease of understanding, it should be noted that certain features of the present disclosure may be described in the singular even if those features are plural or repeated within the disclosed embodiments. Each instance of a feature may include and / or be encompassed in the singular disclosure unless expressly stated to the contrary. For purposes of simplicity and clarity, not all elements of the present disclosure are necessarily shown in every figure or described in detail below. However, it should be understood that the following description may apply equally to any and / or all of multiple components unless expressly stated to the contrary. Moreover, for clarity, not every instance of some elements or features is shown in every figure.

[0025] Relative terms such as "proximal," "distal," "advancing," "retracting," and variations thereof may be generally considered with respect to the position, direction, and / or movement of various elements relative to a user / operator / pilot of a device, with "proximal" and "retracting" indicating or referring to being closer to or toward the user, and "distal" and "advancing" indicating or referring to being farther from or away from the user. In some instances, the terms "proximal" and "distal" may be assigned arbitrarily to facilitate understanding of the present disclosure, and such instances 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 device. Additionally, relative terms such as "axial," "circumferential," "longitudinal," "lateral," "radial," and variations thereof generally refer to directions and / or orientations relative to a central longitudinal axis of the disclosed structure or device.

[0026] The term "range" may be understood to mean the maximum measurement of a stated or identified dimension. However, if a range or dimension in question is modified by or identified as "minimum," it may be understood to mean the minimum measurement of the stated or identified dimension. For example, an "outer range" may be understood to mean the outer dimension, a "radial range" may be understood to mean the radial dimension, and a "longitudinal range" may be understood to mean the longitudinal dimension. Instances of "range" may vary (e.g., axially, longitudinally, laterally, radially, circumferentially, etc.) and will be apparent to those skilled in the art from the context of the particular usage. Generally, a "range" may be considered the maximum possible dimension measured according to the intended use, and a "minimum range" may be considered the minimum possible dimension measured according to the intended use. In some instances, a "range" may generally be measured orthogonally in a plane and / or cross-section, but may also be measured differently, such as angularly, radially, circumferentially (e.g., along an arc), etc., as apparent from the particular context.

[0027] The terms "monolithic" and "unitary" shall generally refer to an element made up of or composed of a single structure or basic unit / component. Monolithic and / or unitary elements shall exclude structures and / or functions made up of assembled or otherwise joined multiple individual elements.

[0028] It should be noted that references herein to "one embodiment," "some embodiments," "other embodiments," etc., indicate that the described embodiment(s) may include a particular feature, structure, or characteristic, but not all embodiments necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Moreover, if a particular feature, structure, or characteristic is described in connection with one embodiment, it is within the knowledge of one skilled in the art that the particular feature, structure, or characteristic can also be used in connection with other embodiments, whether or not explicitly described, unless expressly stated to the contrary. That is, it is contemplated that various individual elements described below, even if not explicitly shown in specific combinations, can nevertheless be combined or arranged with one another to form other or additional embodiments, or to complement and / or enhance the described embodiments, as will be understood by one skilled in the art.

[0029] For clarity, certain distinguishing numerical nomenclature (e.g., first, second, third, fourth, etc.) may be used throughout the specification and / or claims to name and / or distinguish variously described and / or claimed features. It should be understood that the numerical nomenclature is not intended to be limiting, but is merely exemplary. In some embodiments, modifications and departures from previously used numerical nomenclature may be made for brevity and clarity. That is, a feature identified as a "first" element may later be referred to as a "second," "third," etc., or may be omitted entirely, and / or another feature may be referred to as the "first" element. The meaning and / or designation of each instance will be apparent to those skilled in the art.

[0030] The following figures illustrate selected components and / or arrangements of an implant for closing the left atrial appendage, a system employing the implant, 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 diagrammatically for simplicity. Additional details regarding some components of the implant and / or system may be shown in greater detail in other figures. While described in the context of left atrial appendage closure, the implant and / or system may also be used for other procedures within a patient's body and / or for percutaneous medical procedures. Similarly, devices and methods described herein with respect to percutaneous placement may also be used for other types of surgical procedures, as appropriate. For example, in some instances, the devices may be used for non-percutaneous procedures. The devices and methods of the present disclosure may be adapted and configured for other uses within the anatomy.

[0031] FIG. 1 illustrates a partial cross-sectional view of a left atrial appendage 10. In some embodiments, the left atrial appendage (LAA) 10 may have a complex shape and / or an irregular surface area. It will be understood that the illustrated LAA 10 is only one example of many possible shapes and sizes of the LAA 10 and may vary from patient to patient. Those skilled in the art will also recognize that the medical devices, systems, and / or methods disclosed herein may be adapted to various shapes and sizes of the LAA 10, as needed. The left atrial appendage 10 may include a generally longitudinal axis 12 disposed along the depth of a body 20 of the left atrial appendage 10. The body 20 may include a sidewall 14 and an ostium 16 forming a proximal opening 18. In some instances, the lateral extent of the ostium 16 and / or sidewall 14 may be less than the depth of the body 20 along the longitudinal axis 12, or the depth of the body 20 may be greater than the lateral extent of the ostium 16 and / or sidewall 14. In some instances, the LAA 10 may narrow abruptly along the depth of the body 20, or the left atrial appendage may maintain a substantially constant lateral extent throughout most of the depth of the body 20. In some instances, the LAA 10 may include a distal-most region formed or arranged as a tail associated with the distal portion of the body 20. In some instances, the distal-most region may project radially or laterally from the longitudinal axis 12.

[0032] In some cases, a device known as a left atrial appendage closure (LAAC) device may be placed within the LAA 10, such as near or within the ostium 16, to seal off the interior of the LAA 10 from the rest of the heart. FIGS. 2 and 3 show diagrams of a left atrial appendage closure (LAAC) device 100. The LAAC device 100 may include an expandable framework 110 configured to shift axially and / or radially along a central longitudinal axis between a fully constrained configuration and a fully unconstrained configuration. In the constrained configuration, the expandable framework 110 may be axially elongated and / or radially compressed. In the unconstrained configuration, the expandable framework 110 may be axially contracted and / or radially expanded.

[0033] As shown in FIG. 3, which illustrates selected features of the LAAC device 100 in an unconstrained configuration, the expandable framework 110 can have a plurality of struts arranged about a central longitudinal axis. In some embodiments, the plurality of struts can define a plurality of cells. In some embodiments, the plurality of cells can be a plurality of closed cells. In some embodiments, the plurality of cells can be a plurality of open cells. In some embodiments, the plurality of cells can include a plurality of open cells and a plurality of closed cells in various combinations and / or arrangements.

[0034] 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 on and / or concentric with the longitudinal axis. Multiple struts may be joined and / or fixedly attached to one another at 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 LAAC device 100 and / or the expandable framework 110 to a delivery device. In some embodiments, the proximal hub 112 may include internal threads configured to be rotatable and / or threadably mateable with the distal end of an externally threaded delivery device. Other configurations for releasably securing the left atrial appendage closure device 100 to a delivery device are also contemplated. As described herein, some structures (features) are not shown in all figures to enhance clarity.

[0035] The expandable framework 110 and / or the plurality of struts may be formed and / or cut from a tubular member. In some embodiments, the expandable framework 110 and / or the plurality of struts may be integrally formed and / or cut from a single member. In some embodiments, the expandable framework 110 and / or the plurality of struts may be integrally formed and / or cut from a single tubular member, and then formed into the desired shape in an unconstrained state and / or heat treated. In some embodiments, the expandable framework 110 and / or the plurality of struts may be integrally formed and / or cut from a single flat member or sheet, and then rolled or formed into a tubular structure, and then formed into the desired shape in an unconstrained state and / or heat treated. Some exemplary means and / or methods for fabricating and / or forming the expandable framework 110 and / or the plurality of struts include laser cutting, machining, punching, stamping, electrical discharge machining (EDM), chemical dissolution, etc. Other means and / or methods are also contemplated.

[0036] In some embodiments, the expandable framework 110 can include at least one anchor member 116 extending radially outward from the expandable framework 110 in an unconstrained configuration. In some embodiments, the expandable framework 110 can include at least one anchor member 116 extending radially outward from the expandable framework 110. In some embodiments, the expandable framework 110 can include at least one anchor member 116 extending radially outward from near a proximal shoulder of the expandable framework 110. In some embodiments, the expandable framework 110 can include at least one anchor member 116 extending radially outward from the expandable framework 110 near a central portion of the expandable framework 110. In some embodiments, the at least one anchor member 116 can be configured to engage the sidewall of the body of the left atrial appendage. In some embodiments, the at least one anchor member 116 can be formed as a J-shaped hook. The J-shaped hook has a free end that extends and / or is oriented proximally relative to the central longitudinal axis of the left atrial appendage closure device 100 and / or the expandable framework 110. Other configurations are also contemplated.

[0037] In some embodiments, the LAAC device 100 may additionally include an occlusion element 120. The occlusion element 120 may be connected to, over, disposed around, and / or radially outward from at least a portion of the expandable framework 110 and / or the plurality of struts, as shown in FIG. 3 . In some embodiments, the occlusion element 120 may be attached to the proximal hub 112 or attached to the expandable framework at the proximal hub 112. In some embodiments, the occlusion element 120 may extend radially outward and / or distally from the proximal hub 112. In some embodiments, the occlusion element 120 may be attached to and / or secured to the expandable framework 110 at multiple discrete locations. In some embodiments, one, some, and / or all of the at least one anchor member 116 may extend through the occlusion element 120, if present.

[0038] In some embodiments, occlusion element 120 may comprise a membrane, fabric, mesh, tissue element, or other suitable structure. In some embodiments, occlusion element 120 may be porous. In some embodiments, occlusion element 120 may be non-porous. In some embodiments, occlusion element 120 may be permeable to selected gases and / or liquids. In some embodiments, occlusion element 120 may be substantially impermeable to selected gases and / or liquids, such as blood, water, etc. In some embodiments, occlusion element 120 may be designed, sized, and / or configured to prevent thrombus and / or embolic material from exiting LAA 10 into the left atrium and / or the patient's bloodstream. In some embodiments, occlusion element 120 may be configured to promote endothelialization after implantation, thereby enabling effective removal of the target site (e.g., the left atrial appendage, etc.) from the patient's circulatory system. Some non-limiting examples of suitable materials for occlusion element 120 are described below.

[0039] As one skilled in the art will appreciate, anatomical structures (features) can vary in size and / or shape. In some embodiments, the LAA can have an irregular (e.g., elongated and / or oval) cross-sectional shape. In some embodiments, the expandable framework 110 is compliant and can substantially conform to and / or sealingly engage the shape and / or geometry of the lateral walls of the LAA 10 when deployed and / or expanded. In some embodiments, the LAAC device 100 can expand to a size, extent, or shape that is smaller than or different from the fully unconstrained configuration defined by the surrounding tissue and / or lateral walls of the left atrial appendage. In some embodiments, the expandable framework 110 can be configured to shape and / or stretch the tissue of the LAA such that the lateral walls of the LAA 10 substantially conform to the contours of the expandable framework 110. Other configurations are also contemplated.

[0040] In some embodiments, the LAAC device 100 can be adapted to assist in sealing around an irregularly shaped ostium 16 of the LAA 10. In some embodiments, as shown in FIGS. 2 and 3 , the LAAC device 100 can be considered to have a generally circular shape. A circular shape may not fit well around an ostium, such as ostium 16, which is not circular but rather oval in shape, or where at least a portion of the ostium has an irregular edge. The following figures show illustrative, but non-limiting, examples of LAAC devices. The LAAC device includes one or more expandable elements that can expand to assist in sealing against the ostium. In some embodiments, the one or more expandable elements can be adapted to absorb or capture blood in order to expand. In some embodiments, the one or more expandable elements can include one or more clotting agents, such as, but not limited to, fibrinogen, to clot the trapped blood within the one or more expandable elements, thereby assisting the one or more expandable elements in expanding into contact with the irregular ostium and maintaining the expanded configuration. It will be understood that this expansion of the one or more expandable elements is distinct from the expansion of the expandable frame 110 from a collapsed configuration for delivery to an expanded configuration for deployment.

[0041] FIG. 4 is a schematic diagram illustrating an exemplary LAAC device 200 including an expandable frame 210. The LAAC device 200 may be considered similar to the LAAC device 100, but includes an expandable element 220. The expandable element 220 extends around a periphery 222 of the expandable frame 210. Because FIG. 4 is a schematic cross-sectional view, the expandable element 220 is shown as one element near the top of the LAAC device 200 (in the orientation shown) and as one element near the bottom of the LAAC device 200. It will be understood that the expandable element 220 extends around the entire periphery 222 of the expandable frame 210. For example, the periphery 222 may be considered to extend along the periphery of the expandable frame 210.

[0042] The expandable element 220 may be formed from a fabric or a polymeric sheet or layer and is adapted to allow blood to flow into the expandable element 220. In some cases, the expandable element 220 may be open at a proximal end 224 of the LAAC device 200 to capture blood flowing into the LAA 10 in the direction indicated by arrow 226. In some cases, the expandable element 220 may be open at a distal end 228 of the LAAC device 200 to capture blood flowing out of the LAA 10 in the direction indicated by arrow 230. In some cases, the expandable element 220 may be porous to blood, allowing blood moving in either direction to flow into the expandable element 220.

[0043] The expandable element 220 may include a clotting agent, such as, but not limited to, fibrinogen, disposed within the expandable element 220 to clot blood flowing into the expandable element 220. In some cases, the expandable element 220 may be filled with a material that swells in response to contact with water. For example, the expandable element 220 may be filled with a hydrogel. Because water is a major component of blood, the expandable element 220 swells after deployment, thereby assisting in the formation of a seal between the LAAC device 200 and the irregular ostium. In some cases, the expandable element 220 may include a shape-memory foam that expands after the LAAC device 200 is implanted.

[0044] Figure 5 is an enlarged schematic diagram of a two-layer bag filter 300 that can be used to form an expandable element. Figures 6 and 7 show, by way of non-limiting example, an illustration of an expandable element that can be formed using multiple bag filters 300. In some cases, the two-layer bag filter 300 can include an inner layer 310 and an outer layer 320. The inner layer 310 and the outer layer 320 can be intermittently secured together via stitches 330 to form a cone-like structure, as shown. In some cases, the bag filter 300 can be formed by forming cone shapes from a suitable material and then securing adjacent cone shapes together by gluing or perhaps suturing.

[0045] The inner layer 310 and the outer layer 320 can be formed from any suitable material, including a blood-permeable material. In some cases, the inner layer 310 and the outer layer 320 are formed from a blood-impermeable material. Examples of suitable materials for the inner layer 310 and the outer layer 320 include fibers or sheets or permeable sheets of fluoropolymers such as PET (polyethylene terephthalate), polyester, polyurethane, and ePTFE (expanded polytetrafluoroethylene). In some cases, the bag filter 300 can include a coagulant. The coagulant is coated on the inner surface of the bag filter 300. In some cases, the bag filter 300 can be essentially filled with the coagulant or at least partially filled with the coagulant.

[0046] As described above, the bag filters 300 can be combined to form an expandable element. The expandable element can then be secured to a LAAC device, such as the LAAC device 100, to form a LAAC device that better seals against an irregular ostium. FIG. 6 is a schematic diagram illustrating an expandable element 400 assembled from multiple bag filters 300. As shown in FIG. 5, the expandable element 400 can be formed by periodically suturing an inner layer (e.g., the inner layer 310) and an outer layer (e.g., the outer layer 320). The dashed line 410 can be considered to represent the periphery of the LAAC device to which the expandable element 400 can be secured. It will be appreciated that because the expandable element 400 is wider than the periphery of the LAAC device represented by the dashed line 410, the expandable element 400 can be folded over the periphery of the LAAC device and thus positioned to seal between the LAAC device and the irregular ostium.

[0047] FIG. 7 is a schematic diagram of an expandable element 500 that is subsequently secured to a LAAC device, such as LAAC device 100, to form a LAAC device that better seals against irregular ossicles. The expandable element 500 may be considered to include a first expandable element 510 and a second expandable element 520 positioned directly above the first expandable element 510. Each of the first expandable element 510 and the second expandable element 520 may be considered equivalent to the expandable element 400 shown in FIG. 6. The addition of the second expandable element provides additional sealing around the periphery of the LAAC device, indicated by dashed line 410. In some cases, the second expandable element 520 may be positioned such that the flared openings of the filter bags within the second expandable element 520 fit between the flared openings of the filter bags within the first expandable element 510.

[0048] 8 is a schematic diagram of an exemplary LAAC device 600 including an expandable frame 610. The expandable frame 610 may be similar to the expandable frame 110 described in connection with FIG. 2 and may or may not include a covering such as covering 120. The LAAC device 600 includes an expandable element 620 extending along a periphery 630 of the LAAC device 600. As shown, the expandable element 620 includes a plurality of bag filters 300, some of which are positioned with their open ends facing proximally to capture blood flowing toward or into the LAA 10 in the direction indicated by arrow 640, and some of which are positioned with their open ends facing distally to capture blood flowing away from or out of the LAA 10 in the direction indicated by arrow 650. In some cases, the individual bag filters 300 may have closed ends. In some cases, an individual bag filter 300 may have two open ends, while including a one-way valve that allows blood to flow in one direction while preventing flow in the opposite direction.

[0049] FIG. 9 is a schematic diagram of an exemplary LAAC device 700 including an expandable frame 710. The expandable frame 710 may be similar to the expandable frame 110 described in connection with FIG. 2 and may or may not include a covering such as covering 120. The LAAC device 700 includes a corrugated tri-layer expandable element 720. The corrugated tri-layer expandable element 720 may be configured to swell to conform to and seal an irregular ostium 716, as shown in FIG. 10. The corrugated tri-layer expandable element 720 includes an inner layer 730 that fits against the outer surface of the expandable frame 710, an outer layer 740 configured to seal the irregular ostium 716, and a middle layer 750 that is alternately connected to or adjacent to the inner layer 730 and the outer layer 740. In some cases, the middle layer 750 may be similar to the layers of material of the inner layer 730 and the outer layer 740. As an example, the architecture of the middle layer 750 may be similar to the interleaved bag shown in Figure 7. In some cases, the swellable material may or may not be secured to the middle layer 750. The swellable material may be secured only to the inner layer 730, only to the outer layer 740, or in some cases, to all of the inner layer 730, outer layer 740, and middle layer 750.

[0050] FIG. 10 shows the LAAC device 700 positioned within an irregular stoma 716. As shown, the corrugated, three-layered expandable element 720 expands or swells to fill the space, thereby sealing against the irregular stoma 716. In some cases, the space between the inner layer 730 and the outer layer 740 is filled with blood. In some cases, the space between the inner layer 730 and the outer layer 740 may contain a clotting agent to clot blood that enters the space. In some cases, at least the outer layer 740 may be formed of a blood-permeable material to allow blood to enter the space between the inner layer 730 and the outer layer 740. Examples of suitable materials include fabrics, sheets, or permeable sheets of PET (polyethylene terephthalate), polyester, polyurethane, and fluoropolymers such as ePTFE (porous polytetrafluoroethylene).

[0051] FIG. 11 is a schematic diagram of an exemplary valved mesh 800 that can be used as an expandable element of a LAAC device. As shown, the valved mesh 800 includes a first component 810 positioned in the XY plane and a second component 820 positioned in the YZ plane. It is understood that this is merely an example, and the valved mesh 800 is not necessarily positioned precisely in an XYZ coordinate system with the components positioned at right angles, but may instead form other angles. Each of the first component 810 and the second component 820 can be considered to include a plurality of one-way valves 830. The one-way valves 830 control the direction(s) in which blood flow through the valved mesh 800 is permitted and prohibited. In some cases, the valved mesh 800 can include a clotting agent that coagulates blood that enters the valved mesh 800, causing the valved mesh 800 to swell.

[0052] As will be appreciated, in some cases, a covering (e.g., occlusion element 120, etc.) stretched across expandable frame 110 may need to accommodate changes in the dimensions of expandable frame 110. In other words, the covering may need to be stretchable. FIGS. 12A, 12B, and 12C together show details of a covering 900 that may be used with the LAAC devices described herein. Covering 900 includes threads 910 made from relatively thick fibers. Threads 920 are stretched across the spaces between the relatively thick fibers that form threads 910. Threads 920 are formed from relatively thin fibers. In some cases, threads 910 may be formed from fibers having an average diameter in the range of 5-10 μm, while threads 920 may be formed from fibers having an average diameter in the range of 25-100 μm. In some cases, threads 910 are arranged in a honeycomb pattern, but not all cases require such an arrangement.

[0053] In some cases, yarn 910 may be formed from a fiber including a relatively large amount of elastomer and a relatively small amount of a second polymer, such as, but not limited to, PET (polyethylene terephthalate). In some cases, yarn 910 may be formed from a fiber that is at least 50% elastomer, and yarn 920 may be formed from a fiber that is at least 50% PET. In some cases, yarn 910 may be formed from a fiber that is about 70% elastomer and about 30% PET. In some cases, yarn 920 may be formed from a fiber that is a relatively large amount of elastomer and a relatively small amount of a second polymer, such as, but not limited to, PET (polyethylene terephthalate). In some cases, yarn 920 may be formed from a fiber that is about 30% PET and about 70% elastomer. The elastomers used in yarns 910 and 920 may include one or more of a fluoroelastomer, a polyurethane elastomer, PEBAX®, a thermoplastic elastomer, a copolyester elastomer, a hydrophilic elastomer, polyamide 11, or a polyether segment.

[0054] FIGS. 12B and 12C together show how covering 900 responds to applied force. In particular, FIGS. 12B and 12C together show that uniform porosity is achieved regardless of the direction of applied tension, as indicated by arrows 930, 940, 950, and 960. In FIG. 12C, mesh 970 can be seen to have uniform pore sizes. In some cases, covering 900 may be considered to exhibit auxetic properties. In some cases, covering 900 may include materials such as urethane or nylon. In some cases, covering 900 may also include radiopaque elements. In some cases, covering 900 may be a woven matrix formed in an auxetic pattern such that in-plane radial stretch and flexibility are uniformly distributed with respect to porosity and hemostasis of hemodynamic flow.

[0055] The devices described herein, as well as their various components, can be manufactured essentially by molding, casting, machining, the like, or any other suitable technique. Furthermore, the various structures can include materials commonly used in medical devices, such as metals, metal alloys, polymers, metal-polymer composites, ceramics, combinations thereof, the like, or any other suitable material. These materials can include transparent or translucent materials to aid in visualization during procedures. Examples of suitable metals and metal alloys include stainless steel (e.g., 304V, 304L, and 316LV stainless steel), mild steel, nickel-titanium alloys (e.g., linear elastic and / or superelastic nitinol), other nickel alloys (e.g., nickel-chromium-molybdenum alloys (e.g., UNS: N06625 (INCONEL® 625), UNS: N06022 (HASTELLOY® C-22®), UNS: N10276 (HASTELLOY® C-22®)), and the like. Nickel-copper alloys (e.g., UNS: N04400 (MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc.)), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 (MP35-N®, etc.)), nickel-molybdenum alloys (e.g., UNS: N10665 (HASTELLOY® ALLOY B2 (registered trademark), etc.), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten alloys or tungsten alloys, etc.), cobalt-chromium alloys, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003 (ELGILOY (registered trademark), PHYNOX (registered trademark), etc.), platinum-strengthened stainless steel, combinations thereof, etc.

[0056] Examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene (ETFE), fluorinated ethylene-propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® manufactured by DuPont), polyether block esters, polyurethanes, polypropylene (PP), polyvinyl chloride (PVC), polyether-esters (e.g., ARNITEL® manufactured by DSM Engineering Plastics), ether or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalates and / or other polyester elastomers manufactured by DuPont, such as HYTREL®), polyamides (e.g., DURETHAN® or Elf® manufactured by Bayer), and the like. Atochem's CRISTAMID®), elastomeric polyamides, block polyamide / ethers, polyether block amides (PEBA, e.g., PEBAX®), ethylene-vinyl acetate copolymers (EVA), silicones, 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 (e.g., GRILAMID® manufactured by EMS), perfluoro(propyl vinyl ether) (PFA), ethylene-vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), polycarbonate, ionomer, biocompatible polymer, other suitable material, or mixtures, combinations, copolymers, polymer / metal composites, etc.

[0057] In some embodiments, the systems and / or other elements disclosed herein may include a woven material disposed over or within the structure. The woven material may be composed of a biocompatible material, such as a polymeric material or a biomaterial configured to promote tissue growth. In some embodiments, the woven material may include a bioabsorbable material. Examples of suitable woven materials include, but are not limited to, polyethylene glycol (PEG), nylon, polytetrafluoroethylene (PTFE, ePTFE), polyolefin materials (e.g., polyethylene, polypropylene), polyester, polyurethane, and mixtures or combinations thereof.

[0058] In some embodiments, the systems and / or other elements disclosed herein may include and / or be formed from fibrous materials. Examples of suitable fibrous materials may include flat, shaped, twisted, textured, pre-shrunk, or unshrunk synthetic yarns. Suitable synthetic biocompatible yarns for use in the present disclosure include, but are not limited to, polyester (including polyethylene terephthalate (PET) polyester), polypropylene, polyethylene, polyurethane, polyolefin, polyvinyl, polymethyl acetate, polyamide, naphthalenedicarboxylic acid derivatives, natural silk, polytetrafluoroethylene, and the like. Furthermore, at least one of the synthetic yarns may be a metal, glass, or ceramic yarn or fiber. Useful metal yarns may include yarns formed from or including stainless steel, platinum, gold, titanium, tantalum, or Ni-Co-Cr-based alloys. The yarns may further include carbon, glass, or ceramic fibers. Desirably, the threads are formed from thermoplastic materials, including, but not limited to, polyester, polypropylene, polyethylene, polyurethane, polynaphthalene, polytetrafluoroethylene, etc. The threads may be multifilament, monofilament, or spun. The type and denier of the thread selected may be selected in such a way as to form a biocompatible and implantable prosthesis, and more particularly, a vascular structure, having desired properties.

[0059] In some embodiments, the systems and / or other components disclosed herein may include and / or be treated with suitable therapeutic agents, such as antithrombotic agents (e.g., heparin, heparin derivatives, urokinase, PPack (dextrophenylalanine-proline-arginine-chloromethylketone)), antiproliferative agents (e.g., enoxaparin, angiopeptin, monoclonal antibodies capable of inhibiting smooth muscle cell proliferation, hirudin, acetylsalicylic acid), anti-inflammatory agents (e.g., dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, mesalamine), antitumor / antiproliferative / antimitotic agents (e.g., paclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin, thymidine kinase inhibitors), anesthetic agents (e.g., lidocaine, bupivacaine, ropivacaine), and the like. These include anticoagulants (e.g., D-phenylalanine-proline-arginine chloromethyl ketone, RGD peptide-containing compounds, heparin, antithrombin compounds, platelet receptor antagonists, antithrombin antibodies, antiplatelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick-derived antiplatelet peptides), vascular cell growth promoters (e.g., growth factor inhibitors, growth factor receptor antagonists, transcription activators, and translation promoters), vascular cell growth inhibitors (e.g., growth factor inhibitors, growth factor receptor antagonists, transcription repressors, translation repressors, replication inhibitors, inhibitory antibodies, antibodies against growth factors, bifunctional molecules consisting of a growth factor and a cytotoxin, and bifunctional molecules consisting of an antibody and a cytotoxin), cholesterol-lowering agents, vasodilators, and agents that interfere with endogenous vasoactive mechanisms.

[0060] It will be understood that this disclosure is, in many respects, merely illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps, without exceeding the scope of the invention. This may include, to the extent appropriate, the use of any feature of one illustrative embodiment in another embodiment. The scope of the invention will, of course, be defined in the language in which the appended claims are expressed.

Claims

1. 1. An implantable medical device, comprising: The implantable medical device comprises an expandable frame expandable between a collapsed configuration for delivery and an expanded configuration for deployment, the expandable frame including a periphery defined by the expandable frame; the implantable medical device comprises a coating extending over at least a portion of the expandable frame; The implantable medical device includes an expandable element secured to the periphery, the expandable element adapted to seal an irregular body opening.

2. 10. The implantable medical device of claim 1, wherein the irregular body orifice comprises the ostium of the patient's LAA (left atrial appendage).

3. 3. The implantable medical device of claim 1 or 2, wherein the expandable element comprises a plurality of bag filters disposed around the periphery.

4. 4. The implantable medical device of claim 3, wherein each of the plurality of bag filters has an open end and a closed end, and each of the plurality of bag filters is arranged around the periphery with the open end facing in one direction and the closed end facing in the opposite direction.

5. 4. The implantable medical device of claim 3, wherein each of the plurality of bag filters has an open end and a closed end, and the plurality of bag filters are arranged in an alternating manner around the periphery such that the open end of one bag filter is located adjacent to the closed end of an adjacent bag filter.

6. 4. The implantable medical device of claim 3, wherein at least some of the plurality of bag filters have two open ends and include one-way valves that restrict blood flow through the bag filters.

7. 4. The implantable medical device of claim 3, wherein at least some of the plurality of bag filters include a coagulant disposed therein.

8. 3. The implantable medical device of claim 1 or 2, wherein the expandable element comprises a corrugated three-layer element extending around the periphery, the corrugated three-layer element including an inner layer, an outer layer, and a middle layer having alternating connections to the inner layer and the outer layer.

9. 10. The implantable medical device of claim 8, wherein the corrugated tri-layer element includes a clotting agent.

10. The implantable medical device of claim 1 or 2, wherein the expandable element comprises an omnidirectional valved mesh.

11. The implantable medical device of any one of claims 1 to 10, wherein the implantable medical device comprises a LAAC (Left Atrial Appendage Closure) device.

12. 1. A LAAC (left atrial appendage closure) device adapted to fit within an irregular ostium of a patient's LAA (left atrial appendage), comprising: The LAAC device comprises an expandable frame expandable between a collapsed configuration for delivery and an expanded configuration for deployment, the expandable frame including a periphery defined by the expandable frame; The LAAC device comprises a coating extending over at least a portion of the expandable frame; The LAAC device comprises an expandable element adapted to seal an irregular ostium.

13. The LAAC device of claim 12 , wherein the expandable element comprises a clotting agent.

14. The LAAC device of claim 12 , wherein the expandable element comprises a swellable member.

15. The LAAC device of claim 12 , wherein the expandable element comprises a plurality of bag filters.

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