Implantable medical devices that can conform to irregular anatomical structures

Abstract

An implantable medical device, such as, but not limited to, a left atrial appendage closure (LAAC) device, includes a telescoping frame movable between a collapsed configuration for delivery and an expanded configuration for placement. The telescoping frame may include multiple articulating members biased to the expanded configuration. The telescoping frame may include a biasing member. The LAAC device includes a membrane or cover that extends over the ends of the telescoping frame. In some cases, the LAAC device may be adjustable to better fit non-circular stomas.

Description

[Technical Field]

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

[0002] The left atrial appendage is a small organ attached to the left atrium of the heart. During normal cardiac function, the left atrial appendage contracts to push blood into the left atrium as the left atrium contracts to push blood into the left ventricle. The left atrial appendage's ability to contract helps improve filling of the left ventricle, thereby serving to maintain cardiac output. However, in patients suffering from atrial fibrillation, the left atrial appendage may not contract or empty properly, causing stagnant blood to accumulate within it, potentially leading to the formation of undesirable blood clots within the left atrial appendage.

[0003] A blood clot formed in the left atrial appendage can leave this area and enter the bloodstream. A blood clot traveling through a blood vessel can eventually block a smaller blood vessel downstream, thereby causing a stroke or heart attack. Clinical studies have shown that the majority of blood clots in patients with atrial fibrillation occur in the left atrial appendage. As a treatment, medical devices have been developed that are placed to close the left atrial appendage. Each of the known medical devices and methods has certain advantages and disadvantages. There is a continuing need to provide alternative medical devices and alternative methods for manufacturing and using medical devices. Summary of the Invention

[0004] The present disclosure provides design, material, manufacturing, and use alternatives for medical devices. Examples can be found in implantable medical devices that include a telescoping frame movable between a collapsed configuration for delivery and an expanded configuration for deployment, the telescoping frame being adjustable between having a circular overall shape and having an oval overall shape when in the expanded configuration. A cover spans at least a portion of the telescoping frame. An adjustment mechanism is disposed within the telescoping frame and adapted to controllably adjust the telescoping frame between the circular overall shape and the oval overall shape.

[0005] Additionally or alternatively, the adjustment mechanism may be adapted to controllably adjust the telescoping frame after it has expanded to its expanded configuration. Additionally or alternatively, the adjustment mechanism may include a jack screw mechanism.

[0006] Additionally or alternatively, the jack screw mechanism may include a jack screw; a scissors mechanism engaged with the jack screw such that rotation of the jack screw in a first direction further extends the scissors mechanism radially outward and rotation of the jack screw in an opposite second direction retracts the scissors mechanism radially inward; and a first pad disposed on a first radial length of the scissors mechanism and a second pad disposed on a second radial length of the scissors mechanism, the first pad and second pad adapted to push the telescoping frame radially outward when the jack screw is rotated in the first direction.

[0007] Additionally or alternatively, the cover may be adapted to accommodate changes in the dimensions of the telescoping frame as it is adjusted between a circular overall shape and an oval overall shape. Additionally or alternatively, the cover may include a web of large fibers and smaller fibers spread between the large fibers.

[0008] Additionally or alternatively, the larger fibers may comprise more than 50 percent elastomer and the smaller fibers may comprise more than 50 percent PET (polyethylene terephthalate).

[0009] Additionally or alternatively, the large fibers may comprise 70 percent elastomer and 30 percent PET. Additionally or alternatively, the small fibers may comprise 70 percent PET and 30 percent elastomer.

[0010] Additionally or alternatively, the implantable medical device may include a left atrial appendage closure (LAAC) device. Additionally or alternatively, the LAAC device may be adapted to fit into an ostium of the LAA (left atrial appendage) having a first ratio of the long dimension of the oval shape to the short dimension of the oval shape, and the LAAC device is adapted to achieve an overall oval shape having a second ratio of the long dimension to the short dimension that is greater than the first ratio.

[0011] Another example can be found in a left atrial appendage closure (LAAC) device that includes a telescoping frame movable between a collapsed configuration for delivery and an expanded configuration for placement, the telescoping frame having a non-circular shape with a major axis having a major dimension and a minor axis having a minor dimension when expanded to the expanded configuration, the first ratio being equal to the major dimension divided by the minor dimension. A covering extends over at least a portion of the telescoping frame.

[0012] Additionally or alternatively, the telescoping frame may be adapted to be placed within a non-circular stoma having a stoma major axis with a stoma major dimension and a stoma minor axis with a stoma minor dimension, the non-circular stoma having a native ratio before implantation of the LAAC device equal to the stoma major dimension divided by the stoma minor dimension, and a post-placement ratio greater than the native ratio.

[0013] Additionally or alternatively, the post-deployment ratio may be less than the first ratio. Another example can be found in a method for placing a left atrial appendage closure (LAAC) device in a left atrial appendage (LAA), where the LAA has a non-circular ostium, the non-circular ostium having a first ratio of a major dimension of the non-circular ostium to a minor dimension of the non-circular ostium. The method includes delivering the LAAC device to a location proximate the non-circular ostium, the LAAC being adapted to have an expanded configuration in which the LAAC has a second ratio of a major dimension of the LAAC device to a minor dimension of the LAAC device that is greater than the first ratio. The LAAC device is expanded into the expanded configuration in which the LAAC has the second ratio to reshape the non-circular ostium to a new shape that is more oval than the original shape of the non-circular ostium.

[0014] Additionally or alternatively, the LAAC device may be expandable from a collapsed configuration for delivery and an expanded configuration for deployment, the expanded configuration may provide a second ratio. Additionally or alternatively, the method may further include placing a filler material along one or more sides of the LAAC device after expansion.

[0015] Additionally or alternatively, the method may further include an initial step of placing one or more coils within a distal region of the patient's LAA prior to delivering the LAAC device to a location proximate the non-circular ostium.

[0016] Additionally or alternatively, expanding the LAAC device from the collapsed configuration for delivery and the expanded configuration for deployment may further include actuating an actuation mechanism to cause the LAAC device to achieve the second ratio.

[0017] Additionally or alternatively, the actuating member may include a jack screw and a scissors mechanism engaged with the jack screw such that rotation of the jack screw in a first direction extends the scissors mechanism further radially outward and rotation of the jack screw in an opposite second direction retracts the scissors mechanism radially inward, and actuating the actuating member may include rotating the jack screw.

[0018] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The following figures and detailed description more particularly exemplify these embodiments.

[0019] A more complete understanding of the present invention can be obtained from the following detailed description of various embodiments of the invention when considered in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0020] [Figure 1] This is a partial cross-sectional view of the LAA (left atrial appendage). [Figure 2] FIG. 1 is a perspective view of an exemplary LAAC (left atrial appendage closure) device shown without a cover. [Figure 3] FIG. 3 is a perspective view of the exemplary LAAC device of FIG. 2, including a cover. [Figure 4A] 1 is a cross-sectional view of an exemplary LAAC device including an adjustment mechanism for changing the overall shape of the LAAC, shown prior to actuation of the adjustment mechanism. [Figure 4B] FIG. 4B is a top view of the exemplary LAAC device of FIG. 4A shown before actuation of the adjustment mechanism. [Figure 5A] FIG. 4B is a cross-sectional view of the exemplary LAAC device of FIG. 4A shown after actuation of the adjustment mechanism. [Figure 5B] FIG. 4B is a top view of the exemplary LAAC device of FIG. 4A shown after actuation of the adjustment mechanism. [Figure 6] 1 is a schematic diagram of an exemplary non-circular pore. [Figure 7] FIG. 1 is a schematic diagram of the use of an oval LAAC device to close a non-circular stoma. [Figure 8A] The use of an oval LAAC device and additional filling material to close a non-circular stoma is both demonstrated. [Figure 8B] The use of an oval LAAC device and additional filling material to close a non-circular stoma is both demonstrated. [Figure 9A]10A and 10B are presented together with illustrations of exemplary membrane materials that may be used as covers on the LAAC devices described herein. [Figure 9B] 10A and 10B are presented together with illustrations of exemplary membrane materials that may be used as covers on the LAAC devices described herein. [Figure 9C] 10A and 10B are presented together with illustrations of exemplary membrane materials that may be used as covers on the LAAC devices described herein. DETAILED DESCRIPTION OF THE INVENTION

[0021] While the present disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It is to be understood, however, that the invention is not intended to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure.

[0022] 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 present 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 present disclosure. The detailed description and drawings illustrate exemplary embodiments of the present disclosure. However, for clarity and ease of understanding, not all features and / or elements may be shown in every drawing, although it may be understood that the features and / or elements are present unless otherwise specified.

[0023] 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 are assumed to be modified by the term "about," whether explicitly stated or not. 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" can include numbers that are rounded to the nearest significant figure.

[0024] The recitation of numerical ranges by endpoints includes all numbers within that range (eg, 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.

[0025] 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 to include "and / or" unless the content clearly dictates otherwise. For ease of understanding, it should be noted that some features of the present disclosure may be described in the singular even though those features may be plural or repeated within the disclosed embodiments. Each instance of a feature may include and / or be encompassed by the singular disclosure unless expressly stated to the contrary. For simplicity and clarity, not every element of the present disclosure is necessarily shown in every figure or described in detail below. However, it will be understood that the following description may apply equally to any and / or all of a component that is present more than once, unless expressly stated to the contrary. Moreover, for clarity, not every instance of some elements or features may be shown in every figure.

[0026] Relative terms such as “proximal,” “distal,” “advance,” “retract,” and variations thereof may generally be considered with respect to the position, orientation, and / or movement of various elements relative to a user / operator / manipulator of a device, with “proximal” and “retract” indicating or referring to being closer to or toward the user, and “distal” and “advance” indicating or referring to being farther from or away from the user. In some cases, 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 body lumen, a lumen such as a blood vessel, or within a device. Still other relative terms, such as “axial,” “circumferential,” “longitudinal,” “lateral,” “radial,” and / or variations thereof, generally refer to directions and / or orientations relative to a central longitudinal axis of the disclosed structure or device.

[0027] The terms "monolithic" and "unitary" shall generally refer to an element or elements made from or consisting of a single structure or base unit / element. Monolithic and / or unitary element shall exclude structures and / or features made by assembling or otherwise joining together multiple separate elements.

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

[0029] For purposes of 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 various features of the specification and / or claims. It should be understood that the numerical nomenclature is not intended to be limiting and is merely exemplary. In some embodiments, variations 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. element, or may be omitted entirely, 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 one of ordinary skill in the art.

[0030] The following figures illustrate selected components and / or arrangements of implants for occluding the left atrial appendage, systems for occluding the left atrial appendage, and / or methods of using the implants and / or systems. Note that in any given figure, some features may not be shown or may be shown diagrammatically for simplicity. Further details regarding some of the components of the implants and / or systems may be shown in greater detail in other figures. While described in the context of occluding the left atrial appendage, the implants and / or systems may also be used in other interventional and / or percutaneous medical procedures within a patient. Similarly, devices and methods described herein with respect to percutaneous placement may also be used in other types of surgical procedures, as appropriate. For example, in some instances, the devices may be used in non-percutaneous procedures. Devices and methods according to the present disclosure may also be adapted and configured for other uses within anatomical structures.

[0031] FIG. 1 is a partial cross-sectional view of a left atrial appendage 10. In some embodiments, the left atrial appendage (LAA) 10 may have a complex geometry and / or an irregular surface area. It will be understood that the illustrated LAA 10 is only one of many possible shapes and sizes of the LAA 10, which 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 sizes and shapes of the LAA 10, as needed. The left atrial appendage 10 may have 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 lateral wall 14 and an ostium 16 forming a proximal ostium 18. In some examples, the lateral extent of the ostium 16 and / or the lateral wall 14 may be equal to or 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 the lateral wall 14. In some instances, the LAA 10 may narrow rapidly along the depth of the body 20, or the left atrial appendage may maintain a substantially constant lateral length along 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-like element associated with a distal portion of the body 20. In some instances, the distal-most region may project radially or laterally away from the longitudinal axis 12.

[0032] In some examples, a device known as a left atrial appendage closure (LAAC) device may be implanted within the LAA 10, such as near or within the ostium 16, to seal the interior of the LAA 10 from the remainder of the interior of the heart. FIGS. 2 and 3 present diagrams of a left atrial appendage closure (LAAC) device 100. The LAAC device 100 may include a telescoping 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 fully constrained configuration, the telescoping framework 110 may be axially lengthened and / or radially compressed. In the fully unconstrained configuration, the telescoping framework 110 may be axially shortened and / or radially expanded.

[0033] As seen in FIG. 3 , which illustrates selected features of the LAAC device 100 in a fully unconstrained configuration, the telescoping framework 110 may have a plurality of struts arranged about a central longitudinal axis. In some embodiments, the plurality of struts may 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.

[0034] The telescoping 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 coaxial with the longitudinal axis. Multiple struts may be joined to one another at 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 left atrial appendage closure device 100 and / or the telescoping framework 110 to a delivery device. In some embodiments, the proximal hub 112 may include internal threads configured to rotatably and / or threadably engage a male-threaded distal end of a delivery device. Other configurations for releasably securing the left atrial appendage closure device 100 to a delivery device are also contemplated. As discussed herein, some features are not shown in all figures to improve clarity.

[0035] The elastic framework 110 and / or the plurality of struts may be formed and / or cut from a tubular member. In some embodiments, the elastic framework 110 and / or the plurality of struts may be integrally formed and / or cut from a unitary member. In some embodiments, the elastic framework 110 and / or the plurality of struts may be integrally formed and / or cut from a unitary tubular member, and then formed and / or heat-set into the desired shape in the fully unconstrained configuration. In some embodiments, the elastic framework 110 and / or the plurality of struts may be integrally formed and / or cut from a unitary flat member or sheet, and then rolled or formed into a tubular structure, and then formed and / or heat-set into the desired shape in the fully unconstrained configuration. Some exemplary means and / or methods of fabricating and / or forming the elastic 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] As will be appreciated by those skilled in the art, anatomical features may 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 some embodiments, the elastic framework 110 may be malleable and, when placed and / or expanded within the left atrial appendage, substantially conform to and / or sealingly engage the shape and / or geometry of the lateral walls of the left atrial appendage. In some embodiments, the left atrial appendage closure device 100 may expand to a size, range, or shape that is smaller than or different from the fully unconstrained configuration, as determined by the surrounding tissue and / or lateral walls of the left atrial appendage. In some embodiments, the elastic framework 110 may be configured to shape and / or stretch the tissue of the left atrial appendage such that the lateral walls of the left atrial appendage substantially conform to the contours of the elastic framework 110. Other configurations are also contemplated.

[0037] In some embodiments, the telescoping framework 110 may include at least one anchoring member 116 extending radially outward from the framework in a fully unconstrained configuration. In some embodiments, the telescoping framework 110 may include at least one anchoring member 116 extending radially outward from the telescoping framework 110. In some embodiments, the telescoping framework 110 may include at least one anchoring member 116 extending radially outward from the telescoping framework 110 near a proximal shoulder of the telescoping framework 110. In some embodiments, the telescoping framework 110 may include at least one anchoring member 116 extending radially outward from the telescoping framework 110 near a central portion of the telescoping framework 110. In some embodiments, the at least one anchoring member 116 may be configured to engage a lateral wall of the body of the left atrial appendage. In some embodiments, at least one anchoring member 116 may be formed as a J-shaped hook having a free end extending and / or directed proximally relative to the central longitudinal axis of the left atrial appendage closure device 100 and / or telescoping framework 110. Other configurations are also contemplated.

[0038] In some embodiments, left atrial appendage closure device 100 may optionally include an occlusion element 120 connected to, disposed on, over, around, and / or radially outward of at least a portion of telescoping framework 110 and / or the plurality of struts, as seen in FIG. 4 . In some embodiments, occlusion element 120 may be attached to proximal hub 112 and / or attached to the telescoping framework at proximal hub 112. In some embodiments, occlusion element 120 may extend radially outward from proximal hub 112 and / or extend distally therefrom. In some embodiments, occlusion element 120 may be attached to and / or secured to telescoping framework 110 at multiple discrete locations. In some embodiments, one, some, and / or all of at least one anchoring member 116 may extend through occlusion element 120, if present.

[0039] In some embodiments, occlusion element 120 may comprise a membrane, fabric, mesh, tissue element, or another 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 fluids. In some embodiments, occlusion element 120 may be substantially impermeable to selected gases and / or fluids, 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 entering the left atrium and / or the patient's bloodstream from the left atrial appendage. In some embodiments, occlusion element 120 may be configured to promote endothelialization after implantation, thereby effectively blocking 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 occlusion element 120 are described below.

[0040] 4A is a cross-sectional view of an exemplary LAAC device 200. The LAAC device 200 may be considered similar to the LAAC device 100, except that it includes an adjustment mechanism 220. The LAAC device 200 may include a telescoping framework 210. The telescoping framework 210 may be expandable between a collapsed configuration for delivery (not shown) and an expanded configuration for deployment (as shown in FIG. 4A). Although not shown, it will be understood that the LAAC device 200 may include a covering, such as, for example, the occlusion element 120 shown and described with respect to FIG. 3.

[0041] The adjustment mechanism 220 may be adapted to change the overall shape of the LAAC device 200 from a generally circular or circular profile, as shown in FIGS. 4A and 4B, to a generally non-circular or oval profile, as shown in FIGS. 5A and 5B. The adjustment mechanism 220 may be considered a jack screw mechanism. In some cases, the adjustment mechanism 220 includes a jack screw 222 extending from a proximal hub 224 to a distal hub 226. In some cases, the jack screw 222 may be adapted to allow rotation of the jack screw 222 by coupling an elongated tool, such as a screwdriver or socket, to the end of the jack screw 222 adjacent the proximal hub 224.

[0042] Adjustment mechanism 220 includes a scissor mechanism 228 that engages with jack screw 222 such that rotation of jack screw 222 can move scissor mechanism 228 radially. As shown in Figures 5A and 5B, rotating jack screw 222 in a first direction can lengthen scissor mechanism 228. Rotating jack screw 222 in an opposite second direction can shorten scissor mechanism 228. Scissor mechanism 228 can include a first pair of scissor members 228a and 228b coupled to jack screw 222 to hold first pair of scissor members 228a and 228b stationary relative to jack screw 222 in addition to allowing jack screw 222 to rotate relative to first pair of scissor members 228a and 228b. Scissor mechanism 228 may include a second pair of scissors members 228c and 228d coupled to jack screw 222 to enable jack screw 222 to threadably engage second pair of scissors members 228c and 228d, meaning that rotation of jack screw 222 moves second pair of scissors members 228c and 228d up and down relative to jack screw 222, thereby shortening or lengthening scissors mechanism 228.

[0043] In some cases, the LAAC device 200 includes a first pad 230 disposed on a first radial length 230a of the scissor mechanism 228 and a second pad 232 disposed on a second radial length 232a of the scissor mechanism 228. The first pad 230 and the second pad 232 are each adapted to push the telescoping framework 210 radially outward when the jack screw 222 is rotated in a first direction. The first pad 230 and the second pad 232 may be formed of any suitable material, including an elastomeric polymer or an elastomeric polymer composite including a more rigid element. The more rigid element may include, for example, a radiopaque filler and element. In some cases, the elastomeric properties of the first pad 230 and the second pad 232 enable the first pad 230 and the second pad 232 to form a grip on the telescoping framework 210.

[0044] 4A-4B and 5A-5B show examples of LAAC devices 200 adapted to allow a physician or other professional installing the LAAC device 200 to actively change its shape to better fit the stoma 16, which is oval rather than circular. In some cases, the LAAC device may not be able to actively change its shape to better fit the stoma 16, but may instead be adapted to passively change the shape of the stoma 16 without undergoing a change in dimensions itself. FIG. 6 shows an exemplary stoma 316 that is oval or even elliptical rather than circular. The stoma 316 has a major axis "A" and a minor axis "B" perpendicular to the major axis "A." An elliptical LAAC device (not shown) placed within the stoma 16 exerts a sealing pressure SP along the major axis "A." A and the confining pressure SP along the minor axis "B" B In some cases, it may be considered to provide a good sealing pressure SP A is beneficial in helping to seal along the mitral valve area found along the lower left of the ostium 316 (in the orientation shown).

[0045] In some cases, a ratio may be used to describe how non-circular the ostium 316 may be and how non-circular (or how elliptical) the corresponding LAAC device may be. For example, the ratio may simply be referred to as A / B, i.e., the dimension along the major axis "A" divided by the dimension along the minor axis "B." In some cases, the LAAC device may have an A / B ratio that is greater than the A / B ratio of the native ostium 316. In some cases, the LAAC device, when deployed, may effectively increase the A / B ratio of the native ostium. As a result, the ostium 316 may have a final A / B ratio that is intermediate between its original A / B ratio and the A / B ratio of the LAAC device implanted within the ostium 316.

[0046] 7 provides an example of this. The elliptical LAAC device 400 has an A / B ratio of 1.5, meaning that the length of its major axis "A" is 1.5 times the length of its minor axis "B." The elliptical LAAC device 400 is inserted into a stoma 416 similar to stoma 316, which has an A / B ratio of 1.2, meaning that the length of the major axis "A" of the stoma 416 is 1.2 times the length of the minor axis "B" of the stoma 416. The LAAC device 400 reshapes the stoma 416 such that the reshaped stoma 416 has an A / B ratio of 1.3. It will be appreciated that the A / B ratio of 1.3 of the reshaped stoma 416 is intermediate between the A / B ratio of the natural stoma and the A / B ratio of the LAAC device 400. Reshaping pore 416 in this manner results in an increased sealing pressure being applied along longitudinal axis "A", as shown by arrows 420 and 422. Reshaping pore 416 in this manner results in an increased sealing pressure SP along longitudinal axis "A". A and possibly a lower sealing pressure SP along the minor axis "B". B However, it has been found that sealing pressure along the long axis "A" is more important in reducing or eliminating leakage around the LAAC device 400. In some instances, leakage has been found to occur primarily along the long axis "A" of the ostium 416. In some cases, the mitral side of the long axis "A" can cause the long axis "A" to lengthen during the cardiac cycle, resulting in more ostial movement along the long axis "A." It is believed that increasing the chronic pressure on the long axis "A" will help maintain a seal during the long axis movement that occurs during the cardiac cycle.

[0047] In some cases, the LAAC device itself may not be sufficient. For example, in some cases, an oval-shaped LAAC device may not completely seal around the stoma. FIG. 8A shows a LAAC device 500 positioned within a stoma 516. The LAAC device 500 at least partially reshapes the stoma 516, providing a good sealing pressure SP along the major axis "A," as indicated by arrows 518 and 520. AAlthough it appears that the LAAC device 500 is being sealed, there is a gap between the LAAC device 500 and the ostium 516 along the minor axis "B." In some cases, a filler material 522 may be provided to fill the gap along the sides between the LAAC device 500 and the ostium 516 to help seal against leakage. The filler material 522 may be, for example, a foam or a hydrogel. The filler material 522 may also be a coil or woven filler. Adding the filler material 522 allows for occlusion, even though the sealing pressure along the minor axis "B" is perhaps lower than what would ideally be desired.

[0048] It will be appreciated that in some cases, the LAAC device may be placed within the LAA 10 to help seal the LAA 10 from the remainder of the interior of the heart, even if the ostium 16 is non-circular. The ostium may be considered to have an A / B ratio as previously described. The LAAC device may be delivered to a location proximate to a non-circular ostium. The LAAC device may be considered to be adapted to be capable of having an expanded configuration in which the LAAC has a second ratio between the major dimension of the LAAC device and the minor dimension of the LAAC device that is greater than the first ratio.

[0049] The LAAC device is expanded to an expanded configuration in which the LAAC has a second ratio to reshape the non-circular stoma to a new shape that is more oval than the original shape of the non-circular stoma. In some cases, the LAAC device is expandable from a collapsed configuration for delivery and an expanded configuration for deployment, the expanded configuration providing the second ratio.

[0050] In some cases, the method may further include disposing a filler material along one or more sides of the LAAC device after expansion. In some cases, the method may further include an initial step of placing one or more coils in a distal region of the LAA before delivering the LAAC device to a location adjacent the non-circular ostium. In some cases, adding one or more coils in the distal region of the LAA may help, for example, prevent tilting of the LAAC device.

[0051] In some cases, expanding the LAAC device from the collapsed configuration for delivery and the expanded configuration for deployment may further include actuating an actuation mechanism to cause the LAAC device to achieve a second ratio. By way of example, the actuation member may include a jackscrew and a scissors mechanism engaged with the jackscrew such that rotation of the jackscrew in a first direction further extends the scissors mechanism radially outward and rotation of the jackscrew in an opposite second direction retracts the scissors mechanism radially inward, and actuating the actuation member includes rotating the jackscrew.

[0052] As will be appreciated, in some cases, a cover (such as the occlusion element 120) spanning the telescopic frame 110 may need to accommodate changes in the dimensions of the telescopic frame 110. In other words, the cover may need to be stretchable. FIGS. 9A, 9B, and 9C together present details of a cover 600 that may be used with the LAAC devices described herein. The cover 600 includes a webbing 610 made from relatively thick fibers. A webbing 620 spans the distance between the relatively thick fibers forming the webbing 610 and is formed from relatively thin fibers. In some cases, the webbing 610 may be formed from fibers having an average diameter in the range of 5-10 μm, and the webbing 620 may be formed from fibers having an average diameter in the range of 25-100 μm. In some cases, the webbing 610 is laid out in a honeycomb pattern, although this is not required in all cases.

[0053] In some cases, webbing 610 may be formed of fibers having a relatively large percentage of elastomer and a relatively small percentage of a second polymer, such as, but not limited to, PET (polyethylene terephthalate). In some cases, webbing 610 may be formed of fibers that are at least 50 percent elastomer, and webbing 620 may be formed of fibers that are at least 50 percent PET. In some cases, webbing 610 may be formed of fibers that include approximately 70 percent elastomer and approximately 30 percent PET. In some cases, webbing 620 may be formed of fibers having a relatively large percentage of PET and a relatively small percentage of elastomer. In some cases, webbing 620 may be formed of fibers that include approximately 30 percent PET and approximately 70 percent elastomer. The elastomers used in webbing 610 and webbing 620 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] 9B and 9C together show how covering 600 responds to applied forces. In particular, FIGS. 9B and 9C together show that applied tension in any direction results in equal porosity, as indicated by arrows 630, 640, 650, and 660. In FIG. 9C, mesh 670 can be seen as having equal pore sizes. In some cases, covering 600 may be considered to exhibit auxetic properties. In some cases, covering 600 may include materials such as urethane or nylon. In some cases, covering 600 may include radiopaque elements. In some cases, covering 600 may be a woven substrate formed with an auxetic pattern, whereby stretch and compliance in the planar radial axis are evenly and consistently distributed with respect to hemodynamic flow and hemostasis porosity.

[0055] The devices described herein, and their various components, may be manufactured according to essentially any suitable manufacturing technique, including molding, casting, machining, etc., or any other suitable technique. Additionally, the various structures may include materials commonly associated with medical devices, such as metals, metal alloys, polymers, metal-polymer composites, ceramics, combinations thereof, etc., or any other suitable material. These materials may include transparent or translucent materials to aid in visualization during procedures. Some examples of suitable metals and metal alloys include stainless steels, such as 304V, 304L, and 316LV stainless steels; mild steel; nickel-titanium alloys, such as linear elastic and / or superelastic nitinol; other nickel alloys, e.g., nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as INCONEL® 625; UNS: N06022, such as HASTELLOY® C-22®; HASTELLOY® Nickel-cobalt alloys (e.g., UNS:N10276 such as 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:R30035 such as MP35-N™), nickel-molybdenum alloys (e.g., 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:R30003, such as ELGILOY®, PHYNOX®); platinum-rich stainless steels; combinations thereof, etc.; or any other suitable material.

[0056] 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 esters, polyurethanes, polypropylene (PP), polyvinyl chloride (PVC), polyetheresters (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalates and / or other polyester elastomers such as HYTREL® available from DuPont), polyamides (e.g., DURETHAN® or Elf® available from Bayer), and the like. CRISTAMID™ available from Atochem), elastomeric polyamides, block polyamide / ethers, polyether block amides (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 (e.g., EMS American Examples include GRILAMID® available from Grillon, perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxies, polyvinylidene chloride (PVdC), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, and the like.

[0057] In some embodiments, the systems and / or other elements disclosed herein may include a woven material disposed on or within the structure. The woven material may be composed of a biocompatible material, such as a polymeric material or a biomaterial, adapted to promote tissue ingrowth. In some embodiments, the woven material may include a bioabsorbable material. Some examples of suitable woven materials include, but are not limited to, polyethylene glycol (PEG), nylon, polytetrafluoroethylene (PTFE, ePTFE), polyolefin-based materials such as polyethylene, polypropylene, polyester, polyurethane, and / or blends or combinations thereof.

[0058] In some embodiments, the systems and / or other elements disclosed herein may include and / or be formed from textile materials. Some examples of suitable textile materials include synthetic yarns, which may be flat, shaped, twisted, textured, pre-shrunk, or unshrunk. 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, polyolefins, polyvinyls, polymethylacetates, polyamides, naphthalenedicarboxylic acid derivatives, natural silk, and polytetrafluoroethylene. Furthermore, at least one of the synthetic yarns may be a metal yarn, glass, or ceramic yarn or fiber. Useful metal yarns include yarns made from or containing stainless steel, platinum, gold, titanium, tantalum, or Ni-Co-Cr-based alloys. Yarns may also include carbon fiber, glass fiber, or ceramic fiber. Desirably, the yarns are made from thermoplastic materials, including, but not limited to, polyester, polypropylene, polyethylene, polyurethane, polynaphthalene, polytetrafluoroethylene, etc. The yarns may be of the multifilament, monofilament, or spun type. The yarn type and denier selected may be selected to form a biocompatible and implantable prosthesis, and more particularly, a vascular structure, having desirable properties.

[0059] In some embodiments, the systems and / or other elements disclosed herein may include 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 (dextrophenylalanine proline arginine chloromethyl ketone)); antiproliferative agents (such as enoxaparin, angiopeptin, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory agents (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine); antitumor / antiproliferative / antimitotic agents (such as paclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin, and thymidine kinase inhibitors); anesthetic agents (such as lidocaine, bupivacaine, and and ropivacaine, etc.); anticoagulants (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 antiplatelet peptides, etc.); vascular cell growth promoters (growth factor inhibitors, growth factor receptor antagonists, transcription activators, and translation promoters, etc.); vascular cell growth inhibitors (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, bifunctional molecules consisting of an antibody and a cytotoxin, etc.); 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 disclosure. This may include, to the extent appropriate, using any of the features of one illustrative embodiment in other embodiments. The scope of the invention is, of course, defined in the language in which the appended claims are expressed.

Claims

1. 1. An implantable medical device comprising: a telescoping frame movable between a collapsed configuration for delivery and an expanded configuration for deployment, the telescoping frame, when in the expanded configuration, being adjustable between having a circular overall shape and having an oval overall shape; a cover that extends over at least a portion of the telescoping frame; an adjustment mechanism disposed within the telescoping frame, the adjustment mechanism adapted to controllably adjust the telescoping frame between the circular overall shape and the oval overall shape; An implantable medical device comprising:

2. 10. The implantable medical device of claim 1, wherein the adjustment mechanism is adapted to controllably adjust the telescoping frame after the telescoping frame has expanded to its expanded configuration.

3. The implantable medical device of claim 1 or 2, wherein the adjustment mechanism comprises a jack screw mechanism.

4. The jack screw mechanism includes: Jack screws and a scissors mechanism engaged with said jack screw such that rotation of said jack screw in a first direction further extends said scissors mechanism radially outward and rotation of said jack screw in an opposite second direction retracts said scissors mechanism radially inward; a first pad disposed on a first radial length of the scissor mechanism and a second pad disposed on a second radial length of the scissor mechanism, the first pad and the second pad adapted to urge the telescoping frame in a radially outward direction when the jack screw is rotated in the first direction; The implantable medical device of claim 3 , comprising:

5. 5. The implantable medical device of claim 1, wherein the cover is adapted to accommodate changes in dimensions of the telescoping frame as the telescoping frame is adjusted between the circular overall shape and the oval overall shape.

6. The cover is A large web of fibers, small fibers spread between the large fibers; 6. The implantable medical device of claim 5, comprising:

7. 7. The implantable medical device of claim 1, wherein the implantable medical device is adapted to fit into an ostium of the LAA (left atrial appendage) having a first ratio of the long dimension of the oval shape to the short dimension of the oval shape, and the implantable medical device is adapted to achieve an overall oval shape having a second ratio of the long dimension to the short dimension that is greater than the first ratio.

8. 1. A left atrial appendage closure (LAAC) device comprising: a telescoping frame movable between a collapsed configuration for delivery and an expanded configuration for deployment, the telescoping frame having a non-circular shape when expanded to the expanded configuration, the telescoping frame having a major axis with a major dimension and a minor axis with a minor dimension, the first ratio being equal to the major dimension divided by the minor dimension; a cover that extends over at least a portion of the telescoping frame; 1. A LAAC device comprising:

9. 9. The LAAC device of claim 8, wherein the telescopic frame is adapted to be placed within a non-circular ostium having a ostium major axis having a ostium major dimension and a ostium minor axis having a ostium minor dimension, the non-circular ostium having a native ratio before implantation of the LAAC device equal to the ostium major dimension divided by the ostium minor dimension, and a post-placement ratio greater than the native ratio.

10. The LAAC device of claim 9 , wherein the post-deployment ratio is less than the first ratio.

11. 1. A method for placing a left atrial appendage closure (LAAC) device in a left atrial appendage (LAA), the LAA having a non-circular ostium, the non-circular ostium having a first ratio of a major dimension of the non-circular ostium to a minor dimension of the non-circular ostium, the method comprising: delivering the LAAC device to a location adjacent to the non-circular stoma, the LAAC adapted to have an expanded configuration in which the LAAC has a second ratio of a major dimension of the LAAC device to a minor dimension of the LAAC device that is greater than the first ratio; expanding the LAAC device to the expanded configuration, wherein the LAAC has the second ratio, to reshape the non-circular ostium into a new shape that is more oval than the original shape of the non-circular ostium; A method comprising:

12. 12. The method of claim 11, wherein the LAAC device is expandable from a collapsed configuration for delivery and an expanded configuration for deployment, the expanded configuration providing the second ratio.

13. 13. The method of claim 12, further comprising placing a filler material along one or more sides of the LAAC device after expansion.

14. 14. The method of any one of claims 11 to 13, further comprising an initial step of placing one or more coils within a distal region of the LAA prior to delivering the LAAC device to a location adjacent the non-circular ostium.

15. 12. The method of claim 11, wherein expanding the LAAC device from a collapsed configuration for delivery and an expanded configuration for deployment further comprises actuating an actuation mechanism to cause the LAAC device to achieve the second ratio.

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