Patent Description:
<CIT> relates to the reduction of regions of blood stasis and ultimately thrombus formation in such regions, particularly in the atrial appendages of patients with atrial fibrillation. More specifically, the invention relates to procedures and devices for affixing the atrial appendages in an orientation that prevents subsequent formation of thrombus. The invention removes the appendage from the atrium by pulling on it and putting a loop around it to form a sack of the atrial appendage and then cut off from the rest of the heart.

<CIT> relates to a method for surgically closing the passage between the atrium and the atrial appendage or severing the atrial appendage.

<CIT> and <CIT> disclose barrier devices and filter devices respectively which may be deployed at the ostium of a left atrial appendage to block thrombus generated within the left atrial appendage from entering the left atrium and general circulation.

<CIT> discloses an occlusive device including a covering component to modulate passage of blood or thrombus therethrough, and an occlusive frame that includes a plurality of elongate occlusion frame members. The elongate occlusion frame members are arranged to form a generally disk-shaped member. The occlusion frame is at least partially covered by the covering component. The device further includes an anchor frame that includes a plurality of elongate anchor frame members. The device further includes a first hub component from which the elongate frame members extend, and a second hub component from which the elongate frame members extend. The covering component may be bioresorbable.

<CIT> discloses an occlusive device including a frame element having a distal end and a proximal end, and a delivery configuration and a deployed configuration. The occlusive device also includes an occlusive face having a peripheral edge, where the occlusive face positioned toward the proximal end of the frame element. The occlusive device also includes at least one anchor positioned at the peripheral edge of the occlusive face.

While current treatment methods are effective for minimizing migration of thrombus from the left atrial appendage into the general circulation, a need still exists for a percutaneous treatment option which does not result in the long term introduction of foreign matter which may provoke an inflammatory response.

In some aspects, the invention relates to a left atrial appendage closure device comprising a plurality of centrally joined bioabsorbable struts forming an umbrella-like support structure which is concave when viewed from a distal end of the plurality of centrally joined bioabsorbable struts, wherein the umbrella-like support structure has a first radially compact configuration and a second expanded configuration in which second expanded configuration the umbrella-like support structure has a proximal circumferential dimension sized and adapted to span the ostium of a left atrial appendage and a distal extent sized and adapted to be contained within the left atrial appendage; a bioabsobable porous membrane which forms a porous cap coextensive with centrally joined portions of the bioabsorbable struts and which extends distally along at least a portion of the umbrella-like support structure sized and adapted to be contained within the left atrial appendage, wherein the porous membrane is bioabsorbable, the pores of the porous membrane are sized and adapted to retain thrombi within the left atrial appendage when the left atrial appendage closure device is deployed within the left atrial appendage, and the porous membrane includes a tissue growth promoting component. In some aspects, at least some of the bioabsorbable struts of the umbrella-like support structure may be joined near their distal ends to form a closed support structure cage.

In addition or alternatively, the invention relates to a left atrial appendage closure device wherein the bioabsorbable porous membrane is selected from the group consisting of a textile, a nonwoven, a braid, a laser cut sheet, an etched sheet, and a 3D printed article.

In some aspects, the bioabsorbable polymer of the plurality of centrally joined bioabsorbable struts and the polymer of the bioabsorbable porous membrane of the left atrial appendage closure device are selected from the group consisting of polyglycolic acid, polylactic acid, polycaprolactone, polyvalerolactone, poly(<NUM>,<NUM>-dioxane-<NUM>,<NUM>-dione), poly(<NUM>,<NUM>-dioxane-<NUM>-one), poly(p-dioxanone), poly(<NUM>,<NUM>-dioxepan-<NUM>-one), poly(β-R,S-malic acid), poly(α-malic acid), polyhydroxyalkanoates, and mixtures or copolymers thereof.

In some aspects of the invention, the polymer of the plurality of bioabsorbable struts is the same as the polymer of the bioabsorbable porous membrane.

In some aspects of the invention, the polymer of the plurality of centrally joined bioabsorbable struts is different from the polymer of the bioabsorbable porous membrane.

In certain aspects of the invention, the porous membrane includes a tissue growth promoting component selected from the group consisting of fibronectin, vascular endothelial growth factor, and fibroblast growth factor.

In some aspects of the invention the tissue growth promoting component of the left atrial appendage closure device is a layer on the porous membrane.

In certain aspects of the invention the tissue growth promoting component of the left atrial appendage closure device is dispersed within the bioabsorbable porous membrane.

In addition, the thicknesses of the struts of the plurality of centrally joined bioabsorbable struts and of the bioabsorbable porous membrane of the left atrial appendage device of the invention are selected to provide a controlled bioabsorption profile which minimizes release of particulate material.

In some aspects of the invention, the left atrial appendage closure device further comprises a hub which is attached to the centrally joined plurality of bioabsorbable struts and adapted to be releaseably attached to a distal end of a delivery shaft.

In addition or alternatively, the invention includes a method of manufacturing a left atrial appendage closure device comprising the steps of creating a plurality of centrally joined bioabsorbable struts forming an umbrella-like support structure and creating a porous bioabsorbable membrane which forms a porous cap coextensive with centrally joined portions of the bioabsorbable struts and extending distally along at least a portion of the umbrella-like support structure, wherein the porous membrane is fixedly attached to the plurality of centrally joined bioabsorbable struts forming an umbrella-like support structure and wherein the porous membrane includes a tissue growth promoting component. In some aspects of the method of manufacturing a left atrial appendage closure device, at least some of the distal ends of the bioabsorbable struts forming an umbrella-like support structure may be joined to form a closed support structure cage.

In certain aspects of the method of manufacturing a left atrial appendage closure device of the invention, the step of creating the plurality of centrally joined bioabsorbable struts forming an umbrella-like support structure includes one or more of welding, molding, vacuum forming, removing material from a solid workpiece, and 3D printing.

In some aspects of the method of manufacturing a left atrial appendage closure device, the step of creating the porous bioabsorbable membrane which forms a porous cap coextensive with centrally joined portions of the bioabsorbable struts and which extends distally along at least a portion of the umbrella-like support structure includes one or more of weaving, braiding, electrospraying, electrospinning, molding, vacuum forming, laser cutting, etching, and 3D printing.

In addition or alternatively, in the method of manufacturing a left atrial appendage closure device of the invention, the step of creating a plurality of centrally joined bioabsorbable struts forming an umbrella-like support structure and the step of creating a porous bioabsorbable membrane which forms a porous cap coextensive with centrally joined portions of the bioabsorbable struts and which extends distally along at least a portion of the umbrella-like support structure are carried out simultaneously to create a unitary left atrial appendage closure device. In some aspects, at least some of the bioabsorbable struts of the umbrella-like support structure may be joined near their distal ends to form a closed support structure cage.

In addition or alternatively the method of manufacturing a left atrial appendage closure device further comprises attaching a hub to the centrally joined bioabsorbable struts, said hub being adapted to be releaseably attached to a distal end of a delivery shaft.

In some aspects of the invention, left atrial appendage closure device comprises a plurality of bioabsorbable struts having a proximal end and a distal end which are joined at their proximal portions to form an umbrella-like support structure which is concave when viewed from a distal end of the plurality of proximally joined bioabsorbable struts, wherein the umbrella-like support structure has a first compact delivery configuration and a second expanded deployed configuration in which the umbrella-like support structure has a proximal circumferential dimension sized and adapted to span and engage the ostium of a left atrial appendage and a longitudinal extent sized and adapted to be contained within the left atrial appendage; a bioabsorbable porous cap coextensive with the joined proximal portions of the bioabsorbable struts and which extends distally therefrom along at least a portion of the umbrella-like support structure sized and adapted to be contained within the left atrial appendage, wherein the porous cap is bioabsorbable, the pores of the porous cap are sized and adapted to retain thrombi within the left atrial appendage when the left atrial appendage closure device is deployed within the left atrial appendage, and the porous cap includes a tissue growth promoting component. In some aspects, at least some of the bioabsorbable struts of the umbrella-like support structure may be joined near their distal ends to form a closed support structure cage.

In some aspects, the bioabsorbable porous cap of the left atrial appendage closure device of the invention is selected from the group consisting of a textile, a nonwoven, a braid, a laser cut sheet, an etched sheet, and a 3D printed article.

In addition, the bioabsorbable polymer of the plurality of proximally joined bioabsorbable struts and the polymer of the bioabsorbable porous cap of the left atrial appendage closure device of the invention are selected from the group consisting of polyglycolic acid, polylactic acid, polycaprolactone, polyvalerolactone, poly(<NUM>,<NUM>-dioxane-<NUM>,<NUM>-dione), poly(<NUM>,<NUM>-dioxane-<NUM>-one), poly(p-dioxanone), poly(<NUM>,<NUM>-dioxepan-<NUM>-one), poly(β-R,S-malic acid), poly(α-malic acid), polyhydroxyalkanoates, and mixtures or copolymers thereof.

In some aspects of the invention, the polymer of the plurality of bioabsorbable struts is the same as the polymer of the bioabsorbable porous cap.

In certain aspects of the invention, the plurality of proximally joined bioabsorbable struts and the bioabsorbable porous cap of the left atrial appendage closure device are integrally formed.

In some aspects of the invention, the polymer of the plurality of proximally joined bioabsorbable struts of left atrial appendage closure device of the invention is different from the polymer of the bioabsorbable porous cap.

In certain aspects of the invention, the tissue growth promoting component of the left atrial appendage closure device is selected from the group consisting of fibronectin, vascular endothelial growth factor, and fibroblast growth factor.

In some aspects of the invention, tissue growth promoting component of the left atrial appendage device of the invention is a layer on the bioabsorbable porous cap.

In addition or in the alternative, the tissue growth promoting component of the left atrial appendage device of the invention is dispersed within the bioabsorbable porous cap.

In addition or in the alternative, the tissue growth promoting component of the left atrial appendage device of the invention is absorbed within a surface layer of the bioabsorbable porous cap.

In some aspects of the invention, the thicknesses of the plurality of proximally joined bioabsorbable struts and the bioabsorbable porous cap of the left atrial appendage closure device are selected to provide a controlled bioabsorption profile which minimizes release of particulate material.

In addition or in the alternative, the left atrial appendage closure device further comprises a hub attached to the plurality of proximally joined bioabsorbable struts and adapted to be releaseably attached to a distal end of a delivery shaft.

In addition or in the alternative, the invention includes a method of manufacturing a left atrial appendage closure device comprising the steps of creating a plurality of bioabsorbable struts joined at their proximal portions to form a distally opening umbrella-like support structure and creating a porous bioabsorbable cap coextensive with proximally joined portions of the bioabsorbable struts and extending distally along at least a portion of the umbrella-like support structure, wherein the bioabsorbable porous cap is fixedly attached to the plurality of proximally joined bioabsorbable struts forming an umbrella-like support structure and wherein the bioabsorbable porous cap includes a tissue growth promoting component. In some aspects, at least some of the bioabsorbable struts of the umbrella-like support structure may be joined near their distal ends to form a closed support structure cage.

In certain aspects of the method of manufacturing a left atrial appendage closure device, the step of creating the plurality of bioabsorbable struts joined at their proximal portions to form a distally opening umbrella-like support structure includes one or more of welding, molding, vacuum forming, removing material from a solid workpiece, and 3D printing. In some aspects, at least some of the bioabsorbable struts of the umbrella-like support structure may be joined near their distal ends to form a closed support structure cage.

In some aspects of the method of manufacturing a left atrial appendage closure device of the invention, the step of creating the bioabsorbable porous cap which forms a porous cap coextensive with proximally joined portions of the bioabsorbable struts and which extends distally along at least a portion of the umbrella-like support structure includes one or more of weaving, braiding, electrospraying, electrospinning, molding, vacuum forming, laser cutting, etching, and 3D printing.

In the alternative or in addition, the method of manufacturing a left atrial appendage closure device of claim <NUM>, wherein the steps of creating a plurality of bioabsorbable struts joined at their proximal portions to form a distally opening umbrella-like support structure and creating a porous bioabsorbable membrane which forms a porous cap coextensive with the plurality of bioabsorbable struts joined at their proximal portions to form a distally opening umbrella-like support structure which extends distally along at least a portion of the umbrella-like support structure are carried out simultaneously to create a unitary left atrial appendage closure device. In some aspects, at least some of the bioabsorbable struts of the umbrella-like support structure may be joined near their distal ends to form a closed support structure cage.

In some aspects of the method of manufacturing a left atrial appendage closure device of the invention, the bioabsorbable polymer of the plurality of bioabsorbable struts and of the bioabsorbable porous cap is selected from the group consisting of polyglycolic acid, polylactic acid, polycaprolactone, polyvalerolactone, poly(<NUM>,<NUM>-dioxane-<NUM>,<NUM>-dione), poly(<NUM>,<NUM>-dioxane-<NUM>-one), poly(p-dioxanone), poly(<NUM>,<NUM>-dioxepan-<NUM>-one), poly(β-R,S-malic acid), poly(α-malic acid), polyhydroxyalkanoates, and mixtures or copolymers thereof.

In certain aspects of the method of manufacturing a left atrial appendage closure device of the invention the tissue growth promoting component is selected from the group consisting of fibronectin, vascular endothelial growth factor, and fibroblast growth factor.

In addition or in the alternative, the method of manufacturing a left atrial appendage closure device of the invention further comprises a step of attaching a hub to the plurality of bioabsorbable struts joined at their proximal ends, said hub being adapted to be releaseably attached to a distal end of a delivery shaft.

In some aspects of the method of manufacturing a left atrial appendage closure device the invention, the hub is a bioabsorbable hub.

The following description should be read with reference to the drawings wherein like reference numerals indicate like elements throughout the several views. The drawings, which are not necessarily to scale, are not intended to limit the scope of the claimed invention. The detailed description and drawings exemplify aspects of the claimed invention.

Although some suitable dimensions, ranges and/or values pertaining to various components, features and/or specifications are disclosed, one of skill in the art, incited by the present disclosure, would understand desired dimensions, ranges and/or values may deviate from those expressly disclosed unless the context clearly indicates an intended limitation.

All numbers are herein assumed to be modified by the term "about. " The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., <NUM> to <NUM> includes <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>).

It is noted that references in the specification to "an aspect", "some aspects", "other aspects", etc., indicate that the aspect described may include a particular feature, structure, or characteristic, but not every aspect may necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same aspect of the invention. Further, when a particular feature, structure, or characteristic is described in connection with an aspect, it would be within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described unless clearly stated to the contrary.

<FIG> shows a lateral view of an expanded self-expanding left atrial appendage closure device <NUM> and <FIG> shows a axial view of the same device as seen from the distal end, which device comprises a plurality of bioabsorbable struts <NUM>, each having a proximal end and a distal end, which are joined at their proximal portions to form an umbrella-like support structure which is concave when viewed from a distal end of the plurality of proximally joined bioabsorbable struts; a porous cap <NUM> coextensive with the joined proximal portions of the bioabsorbable struts <NUM> and extending distally therefrom along at least a portion of the bioabsorbable struts <NUM>. In some aspects, at least some of the bioabsorbable struts of the umbrella-like support structure may be joined near their distal ends to form a closed support structure cage.

Although the illustrated aspect of the invention has eight bioabsorbable struts <NUM>, it will be appreciated that more or fewer bioabsorbable struts, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> struts, may be employed if desired. Generally fewer struts may reduce the diameter of a collapsed configuration of a left atrial appendage closure device <NUM> to facilitate delivery, while the addition of more bioabsorbable struts <NUM> may tend to provide a smoother wall sealing contour by allowing individual bioabsorbable struts <NUM> flex to a greater or lesser extent to accommodate variations in the shape of an ostium. In some aspects of the invention, at least some of the bioabsorbable struts may be joined at their distal ends to form a closed cage support structure.

The proximal ends of the plurality of bioabsorbable struts <NUM> may assume a generally planar configuration adapted to span the ostium of a left atrial appendage before bending distally to provide a more cylindrical wall engaging portion. The joined proximal ends may form or include a hub <NUM> to be discussed in greater detail below. In some aspects of the invention, the hub <NUM> may be formed as a thickened region of the joined proximal ends of the plurality of bioabsorbable struts <NUM>. Although shown in the figures as slightly protruding proximally from the porous cap <NUM> in the figures for clarity of illustration, it will be appreciated that the hub may be constructed to be flush with the porous cap <NUM> or even slightly recessed therefrom.

Bioabsorbable struts <NUM> may also include one or more optional barbs <NUM> to be discussed in greater detail later.

The invention contemplates a variety of cross-sectional shapes and cross-sectional areas distributed along the length of the struts which are selected to control the rate of bioabsorption in a manner which provides adequate support during endothelialization, provides rapid bioabsorption when support is no longer required, and which minimizes the release of portions of the biodegradable struts <NUM> and/or the porous cap <NUM> membrane which might otherwise constitute undesirable particulate matter debris within the circulatory system.

The bioabsorbable struts <NUM> and the resulting umbrella-like structure may be formed by any of the methods employed in the art to construct similar structures and may include injection molding, blow molding, machining, 3D printing and assembly from individual components. In certain aspects of the invention, the bioabsorbable struts <NUM> or <NUM>' and hub <NUM> may be formed as a separate membrane supporting structure as shown in <FIG>. In some aspects of the invention, the bioabsorbable struts <NUM> may be formed from one or more of polyglycolic acid, polylactic acid, polycaprolactone, polyvalerolactone, poly(<NUM>,<NUM>-dioxane-<NUM>,<NUM>-dione), poly(<NUM>,<NUM>-dioxane-<NUM>-one), poly(p-dioxanone), poly(<NUM>,<NUM>-dioxepan-<NUM>-one), poly(β-R,S-malic acid), poly(α-malic acid), polyhydroxyalkanoates, mixtures or copolymers thereof, and the like. In an exemplary aspect, the bioabsorbable struts <NUM> may be formed from poly-<NUM>-hydroxybutyrate and copolymers thereof.

The porous cap <NUM> of <FIG> and <FIG> may be viewed as providing a generally planar central region which is adapted to span an ostium of a left atrial appendage as well as transitioning to provide a generally cylindrical skirt which is adapted to lie along a lumen wall defined by a left atrial appendage and to improve the lateral sealing ability of the porous cap <NUM> within the left atrial appendage once the device is deployed.

The porous cap <NUM> is formed from a bioabsorbable membranous material which may comprise one or more of polyglycolic acid, polylactic acid, polycaprolactone, polyvalerolactone, poly(<NUM>,<NUM>-dioxane-<NUM>,<NUM>-dione), poly(<NUM>,<NUM>-dioxane-<NUM>-one), poly(p-dioxanone), poly(<NUM>,<NUM>-dioxepan-<NUM>-one), poly(β-R,S-malic acid), poly(α-malic acid), polyhydroxyalkanoates, mixtures or copolymers thereof, and the like. In an exemplary aspect, the porous cap <NUM> membrane may be formed from poly-<NUM>-hydroxybutyrate and copolymers thereof.

The porous cap <NUM> membrane may be a textile, a nonwoven, a braid, a laser cut sheet, an etched sheet or a 3D printed article. In some aspects, the porous cap <NUM> membrane may be formed by one or more of weaving, braiding, electrospraying, electrospinning, molding, vacuum forming, laser cutting, etching, and 3D printing. While the pores of the porous cap <NUM> membrane have been depicted as through pores for ease of illustration in some of the figures, it will be appreciated that for the purpose of promoting tissue ingrowth of endothelial tissue, some or all of the porosity may be disposed at or near the surface of the porous cap <NUM> membrane. Although illustrated in the figures as disposed over the bioabsorbable struts <NUM>, it will be appreciated that the porous cap <NUM> membrane may in the alternative be disposed within a support structure provided by bioabsorbable struts <NUM>.

It also will be appreciated that the plurality of centrally joined bioabsorbable struts <NUM> and the porous cap <NUM> membrane are formed simultaneously as an integrally formed object. In those aspects, it may be desirable to include one or more additional components of the left atrial appendage closure device <NUM> such as hub <NUM>, barbs <NUM> or their equivalents, a tissue growth promoter <NUM>, <NUM>, and the like in the same forming operation. In addition, in such aspects the portions of the bioabsorbable struts <NUM> which are coextensive with the porous cap <NUM> membrane may be present as thickened portions of the porous cap <NUM> membrane rather than as distinctly separate features.

The hub <NUM>, barbs <NUM> or their equivalents, a tissue growth promoter <NUM>, <NUM>, and the like may also be introduced at different stages of the manufacturing operation if desired. Similarly, it may be desirable or convenient to use the same or different bioabsorbable polymers for various components of the left atrial appendage closure device as well as the same or different manufacturing processes for the fabrication of individual components to be assembled in separate steps of a manufacturing method.

In the aspect of the invention illustrated in <FIG> and <FIG>, each bioabsorbable strut <NUM> includes an optional barb <NUM> which is sized and adapted to engage adjacent tissue to minimize migration of a deployed device. Although one barb <NUM> is shown on each bioabsorbable strut <NUM>, one of ordinary skill in the art would appreciate that this arrangement is only illustrative of an aspect of the invention. In other aspects, a strut or struts may have <NUM>, <NUM>, <NUM>, or more barbs per bioabsorbable strut <NUM> and not every bioabsorbable strut <NUM> needs to have the same number of barbs <NUM> as its immediate neighbors. The simple barb <NUM> of <FIG> and <FIG> is intended to be representative of other structures known in the art to inhibit migration of an implanted device. For example, the simple barb <NUM> of <FIG> and <FIG> may be replaced by a two-tipped barb having one tip disposed generally in a proximal direction along the associated bioabsorbable strut while a second tip is disposed generally in a distal direction along the associated bioabsorbable strut <NUM>. Similarly, the barb <NUM> may be replaced with a roughened segment of exposed bioabsorbable strut <NUM> such that each protrusion from the roughened segment of exposed bioabsorbable strut <NUM> may be viewed as a tip of a barb <NUM>. Some barbs <NUM> may be integrally formed with the associated strut while other barbs <NUM> may be formed separately and attached to the bioabsorbable strut <NUM>. It will be appreciated that although the exemplary barbs <NUM> are illustrated as located at the distal margin of the porous cap <NUM> membrane, barbs <NUM> or their equivalents may be distributed at other locations along the associated bioabsorbable strut <NUM> and may extend outward from the surface of the porous cap <NUM> membrane as well as outward from more distal portions of the bioabsorbable struts <NUM>. As discussed above, barbs <NUM> or their equivalents, if present, also may be formed from the previously identified bioabsorbable polymer(s) using the known manufacturing processes.

In the interest of promoting tissue growth into and across the portion of the porous cap <NUM> membrane located at the ostium of the left atrial appendage to permanently seal the ostium prior to the full bioabsorption of the left atrial appendage closure device <NUM>, the devices include a tissue growth promoting component <NUM>, <NUM> which may be dispersed throughout the porous cap <NUM> membrane as shown in <FIG>, preferentially absorbed near one or both surfaces of the porous cap <NUM> membrane, and/or applied as a coating to one or both surfaces of the porous cap <NUM> membrane as shown if <FIG>. If desired or convenient, the tissue growth promoting component <NUM>, <NUM> may also be present within or applied to other components of the left atrial appendage closure device <NUM> such as the bioabsorbable struts <NUM> and barbs <NUM> or their equivalents.

In a further aspect related to the manufacturing of a left atrial appendage closure device <NUM>, a support structure shown in <FIG> provided by bioabsorbable struts <NUM> comprising poly-<NUM>-hydroxybutyrate may be formed separately by, for example, injection molding and then positioned about a mandrel. In an alternate aspect of the manufacturing method, a support structure shown in <FIG>, in which at least some of the bioabsorbable struts <NUM>' may also be joined at their distal end. In a separate step, a porous cap <NUM> membrane may be formed over a portion of the bioabsorbable struts <NUM> and the mandrel by electrospinning filaments of poly-<NUM>-hydroxybutyrate. In some aspects, the bioabsorbable struts <NUM> may be removed from the mandrel and a porous cap <NUM> membrane may be formed over a portion of the bioabsorbable struts <NUM> and the mandrel by electrospinning filaments of poly-<NUM>-hydroxybutyrate. The filaments may comprise a dispersed tissue growth promoter <NUM> as shown somewhat schematically in <FIG> or a tissue growth promoter <NUM> may be applied to the porous cap <NUM> membrane as a coating or as an adsorbed layer, as shown in <FIG>, in a later step.

The bioabsorbable left atrial appendage closure devices <NUM> of <FIG> and <FIG> may be delivered to the left atrial appendage using delivery catheters and approaches of the art. For example, the bioabsorbable left atrial appendage closure devices <NUM> of <FIG> and <FIG> may be caused to assume a first compact configuration adapted to be received within the distal end of a delivery catheter <NUM>, as shown in <FIG>, prior to being advanced to the deployment site where the devices may be expelled by advancement of delivery shaft <NUM> and/or withdrawal of delivery catheter <NUM>. In such aspects, the bioabsorbable left atrial appendage closure device <NUM> may include a proximal hub <NUM> adapted to releasably mate with a delivery shaft <NUM>, one aspect of which is illustrated in <FIG>.

In the illustrated aspect of <FIG>, the distal tip <NUM> of the delivery shaft <NUM> includes a male threaded portion and the corresponding mating hub <NUM> of the bioabsorbable left atrial appendage closure device <NUM> includes a female threaded aperture adapted to threadably engage the distal tip <NUM> for delivery through and from the delivery catheter <NUM>, including possible recollapse and repositioning within the delivery site before rotation of the deliver shaft and distal tip <NUM> unscrews the distal tip <NUM> from the mating hub <NUM> of the bioabsorbable left atrial appendage closure device <NUM>. It will be appreciated that engagement between the delivery site wall upon self-expansion of the bioabsorbable left atrial appendage closure device <NUM> to assume a second expanded configuration will provide the resistance necessary to allow the distal tip <NUM> to unscrew from the mating hub <NUM>.

It also will be appreciated that other releasable mating connectors known in the art may be used. For example, the female threaded portion of the releasable mating connector may be formed within distal tip <NUM>, while the hub <NUM> includes a mating male threaded portion. In the alternative, friction fit couplings, pin and loop connectors, and even magnetic couplers may be used with due regard for bioabsorbability of the components of the hub <NUM>. The delivery catheter <NUM> and/or the delivery shaft <NUM> may include radiopaque markers to aid in positioning the left atrial appendage closure device <NUM> within the left atrial appendage.

Although the illustrative examples described above relate to closure of a left atrial appendage, it is also contemplated that the device may be used to close other ostia such as that of an aneurysm. In such an aspect, the size and shape of the generally planar central region of the proximal portions of the bioabsorbable struts and porous cap as well as the distal extent of the device as a whole may be modified to better match the ostium and depth of the aneurysm or other lumen.

Claim 1:
A left atrial appendage closure device (<NUM>) comprising:
a plurality of centrally joined bioabsorbable struts (<NUM>) forming an umbrella-like support structure which is concave when viewed from a distal end of the plurality of centrally joined bioabsorbable struts,
wherein the umbrella-like support structure has a first radially compact configuration and a second expanded configuration in which second expanded configuration the umbrella-like support structure has a proximal circumferential dimension sized and adapted to span the ostium of a left atrial appendage and a distal extent sized and adapted to be contained within the left atrial appendage;
a bioabsorbable porous membrane which forms a porous cap (<NUM>) coextensive with centrally joined portions of the bioabsorbable struts and which extends distally along at least a portion of the umbrella-like support structure sized and adapted to be contained within the left atrial appendage,
wherein the porous membrane is bioabsorbable, the pores of the porous membrane are sized and adapted to retain thrombi within the left atrial appendage when the left atrial appendage closure device is deployed within the left atrial appendage, and the porous membrane includes a tissue growth promoting component,
characterized in that
a polymer of the plurality of bioabsorbable struts is the same as a polymer of the bioabsorbable porous cap, and
the plurality of bioabsorbable struts and the porous cap are integrally formed.