Mitral valve prosthesis with improved atrial and / or annular crimping and reduced paravalvular leakage

Abstract

The present invention provides prosthetic heart valve devices with improved fit and / or crimping between the device frame and left atrial tissue and / or between the device base and left atrial annulus tissue to improve shifting of the implanted device and / or reduce paravalvular leakage. The improved fit and / or crimping occurs, in various embodiments, by providing or enabling an asymmetric frame and / or frame base, and / or by providing a lower lip to conform to the asymmetric shape of the atrium and / or to aid in secure positioning within it. An additional benefit of these configurations is reduced paravalvular leakage as a result of the improved fit and seal. In certain embodiments, the asymmetry of the frame aids in device delivery into the atrium.

Description

[Technical Field]

[0001] [Inventor] Saravana B. Kumar, Minnetonka, Minnesota, U.S. citizen Steven D. Kruse, Maple Grove, Minnesota, U.S. citizen Jeffrey R. Stone, Minnetonka, Minnesota, U.S. citizen [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. patent application Ser. No. 17 / 163,910, filed February 1, 2021, entitled "Prosthetic Mitral Valve With Improved Atrial and / or Annular Crimping and Paravalvular Leakage Reduction," and U.S. patent application Ser. No. 62 / 985,411, filed March 5, 2020, entitled "Prosthetic Mitral Valve With Improved Atrial and / or Annular Crimping and Paravalvular Leakage Reduction," the contents of which are incorporated herein in their entireties. [STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT] Not applicable

[0002] The present invention relates to devices and methods for implanting devices into cardiac chambers. More particularly, the present invention relates to improved crimping of an implanted prosthetic heart valve with the left atrium and / or annulus, as well as improved paravalvular leakage and improved delivery and / or recapture. [Background technology]

[0003] The human heart comprises four chambers and four heart valves that assist in the forward (antegrade) flow of blood through the heart. The heart chambers include the left atrium, left ventricle, right atrium, and right ventricle. The four heart valves include the mitral valve, tricuspid valve, aortic valve, and pulmonary valve. See generally FIG. 1.

[0004] The mitral valve, located between the left atrium and left ventricle, helps control the flow of blood from the left atrium to the left ventricle by acting as a one-way valve to prevent backflow into the left atrium. Similarly, the tricuspid valve is located between the right atrium and right ventricle, and the aortic and pulmonary valves are semilunar valves located in the arteries that allow blood to leave the heart. All valves are one-way valves, with leaflets that open to allow forward (antegrade) blood flow. Normally functioning, the leaflets close under pressure from backflowing blood to prevent backflow (retrograde) of blood into the heart chamber that just emptied. For example, when functioning properly, the mitral valve provides a one-way valve between the left atrium and left ventricle, opening to allow antegrade flow from the left atrium to the left ventricle and closing to prevent backflow from the left ventricle to the left atrium. This backflow, when present, is known as mitral regurgitation or mitral valve regurgitation.

[0005] Figure 2 illustrates the relationship of the left atrium, annulus, chordae tendineae, and left ventricle to the mitral valve leaflets. As shown, the superior surface of the annulus forms at least a portion of the floor or inferior surface of the left atrial cavity, and therefore, for purposes of this description, the superior surface of the annulus is defined as marking the inferior boundary of the left atrial cavity.

[0006] Native heart valves can be or become dysfunctional for a variety of reasons and / or conditions, including, but not limited to, disease, trauma, congenital malformations, and aging. These types of conditions can cause the valve structures to fail to close properly, resulting in regurgitant backflow of blood from the left ventricle to the left atrium in the case of mitral valve insufficiency. Figure 3 illustrates regurgitant blood flow with an exemplary dysfunctional mitral valve.

[0007] Mitral regurgitation is a specific problem resulting from a dysfunctional mitral valve, which allows at least some retrograde blood flow from the right atrium back into the left atrium. In some cases, the dysfunction results from mitral valve leaflets that, instead of connecting or coapting to block regurgitation, prolapse into the left atrial cavity, i.e., above the superior surface of the annulus, designated by line or plane A. This regurgitation of blood strains the left ventricle with volume overload, which can result in a series of compensatory adaptations and adjustments by the left ventricle, including remodeling of the size and shape of the ventricular cavity, which changes considerably over the long-term clinical course of mitral regurgitation.

[0008] Regurgitation can generally be a problem with the native heart valves, including the tricuspid, aortic and pulmonary valves, and the mitral valve.

[0009] Thus, in general, native heart valves, such as the mitral valve, may require functional repair and / or support, including partial or complete replacement. Such interventions can take several forms, including open-heart surgery and open-heart implantation of a replacement heart valve. For example, U.S. Patent No. 4,106,129 (Carpentier) describes a procedure that is highly invasive, involves patient risk, and requires not only a long hospital stay but also a very painful recovery period.

[0010] Minimally invasive methods and devices for replacing dysfunctional heart valves are also known, including percutaneous access and catheter-facilitated delivery of replacement valves. Most of these solutions involve a replacement heart valve attached to a structural support, such as a stent, commonly known in the art, or other form of wire network designed to expand upon release from a delivery catheter. See, for example, U.S. Pat. No. 3,657,744 (Ersek) and U.S. Pat. No. 5,411,552 (Andersen). Self-expanding support stents help position the valve and hold the expanded device in place within a subject's heart chamber or blood vessel. This self-expanding approach also presents challenges when, as is often the case, the device is not properly positioned on the first attempt and must therefore be recaptured and repositioned. This recapture process, in the case of a fully or partially expanded device, requires the operator to re-collapse the device to a point that allows the operator to pull the collapsed device back into the delivery sheath or catheter, adjust the inbound position of the device, and then redeploy the adjusted device distally from the delivery sheath or catheter to re-expand it into the appropriate position.Collapsing an already expanded device is difficult because expanded stents or wire networks are generally designed to achieve an expanded state that can withstand contraction or collapse forces.

[0011] In addition to the open-heart surgical approaches described above, gaining access to the target valve can be achieved percutaneously via at least one of the following known access routes: transapical, transfemoral, transatrial, and transseptal delivery techniques.

[0012] Transseptal delivery involves creating an access hole in the septum between the right and left atria. Once delivery and implantation of the prosthetic heart valve device is accomplished, the septal hole is left open to heal on its own or is at least partially sealed. Transseptal delivery and other delivery techniques may require recapture of an at least partially deployed or expanded device within the distal lumen of the delivery catheter to reposition and / or reorient the device prior to delivery, expansion, positioning, and implantation.

[0013] In general, the art has focused on systems and methods that allow for partial delivery of a collapsed valve device using one of the known access routes described above, where one end of the device is released from a delivery sheath or catheter and expanded for initial positioning, followed by full release and expansion when proper positioning is achieved. See, e.g., U.S. Pat. No. 8,852,271 (Murray, III), U.S. Pat. No. 8,747,459 (Nguyen), U.S. Pat. No. 8,814,931 (Wang), U.S. Pat. No. 9,402,720 (Richter), U.S. Pat. No. 8,986,372 (Murray, III), U.S. Pat. No. 9,277,991 (Salahieh), and U.S. Patent Publication Nos. 2015 / 0272731 (Racchini), 2016 / 0235531 (Ciobanu).

[0014] Furthermore, all known prosthetic heart valves are intended to completely replace the native heart valve. Therefore, these replacement heart valves and / or anchoring or tethering structures physically extend from the left atrial cavity, in the case of the mitral valve, and engage the inner annulus and / or leaflets, often securing the native leaflets to the inner annular wall, thereby permanently eliminating all remaining functionality of the native valve and rendering the patient completely dependent on the replacement valve. In other cases, the anchoring structures may extend into the left ventricle and anchor to the left ventricular wall tissue and / or the subannular surface of the apex of the left ventricle. Others may include presence in or engagement with the pulmonary artery. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] U.S. Patent No. 4,106,129 [Patent Document 2] U.S. Patent No. 3,657,744 [Patent Document 3] U.S. Patent No. 5,411,552 [Patent Document 4] U.S. Patent No. 8,852,271 [Patent Document 5] U.S. Patent No. 8,747,459 [Patent Document 6] U.S. Patent No. 8,814,931 [Patent Document 7] U.S. Patent No. 9,402,720 [Patent Document 8] U.S. Patent No. 8,986,372 [Patent Document 9] U.S. Patent No. 9,277,991 [Patent Document 10] US Patent Publication No. 2015 / 0272731 [Patent Document 11] US Patent Publication No. 2016 / 0235531 Summary of the Invention [Problem to be solved by the invention]

[0016] Clearly, there are cases in which the native valve has substantially lost its complete functionality prior to the interventional implantation procedure. In these cases, a preferred solution comprises an implant that does not extend outside of the left atrium, for example, and functions to completely replace the native valve function. However, in many other cases, the native valve remains functional to some extent and may or may not continue to lose functionality after the implantation procedure. In these cases, a preferred solution involves the delivery and implantation of a valve device that can function as both a supplemental or augmenting valve without damaging the native leaflets to preserve native valve function for as long as it exists, while also being able to completely replace the native function of a valve that is slowly losing most or all of its function after implantation of a prosthetic valve.

[0017] In all cases, including two-chamber solutions, paravalvular leak (PVL) can occur as a result of insufficient sealing or crimping of the prosthetic valve device and native heart chamber tissue, including, but not limited to, the annular seal, which can sometimes result from migration of the implanted device within the heart chamber. In the exemplary case of the mitral valve, PVL can result in retrograde leakage of blood from the left ventricle into the left atrium, reducing cardiac efficiency. Lack of crimping of the seal can occur for several reasons.

[0018] For example, a patient may have at least some calcification within the heart chamber, particularly on the annular surfaces, which acts to reduce compliance of that calcified tissue. This loss of compliance reduces the ability of the tissue and prosthetic heart valve device to seal against each other during implantation, leaving gaps between the tissue and the device. The mitral and tricuspid annulus are subject to calcification, which can lead to poor sealing between the implanted prosthetic heart valve device and the PVL.

[0019] As shown, the left atrium further comprises an asymmetric shape which may result in suboptimal crimping by the frame of the device against the atrial wall and / or tissue and / or the base of the device against the annulus.

[0020] Certain embodiments of the invention described herein are readily applicable to single or dual chamber solutions unless otherwise specified. Furthermore, certain embodiments discussed herein may be generally applicable to preserving and / or replacing native valve function with improved crimping and / or PVL mitigation and / or delivery / recapture, and thus are not limited to the mitral valve but may be expanded to include devices and methods for treating the tricuspid, aortic, and / or pulmonary valves.

[0021] Various embodiments of some of the inventions disclosed herein address, among other things, these problems. [Means for solving the problem]

[0022] The present invention provides prosthetic heart valve devices with improved fit and / or crimping between the device frame and left atrial tissue and / or between the device base and left atrial annulus tissue to improve shifting of the implanted device and / or reduce paravalvular leakage. The improved fit and / or crimping occurs, in various embodiments, by providing or enabling an asymmetric frame and / or frame base, and / or by providing a lower lip to conform to the asymmetric shape of the atrium and / or to aid in secure positioning within it. An additional benefit of these configurations is reduced paravalvular leakage as a result of the improved fit and seal. In certain embodiments, the asymmetry of the frame aids in device delivery into the atrium. [Brief explanation of the drawings]

[0023] [Figure 1] Certain features of the heart are shown in cross section. [Figure 2] FIG. 1 is a cross-sectional perspective view of the left side of the heart. [Figure 3] FIG. 1 is a cross-sectional view of the heart showing retrograde blood flow resulting from mitral valve regurgitation compared to normal blood flow. [Figure 4A]FIG. 1 is a partial cutaway side view of one embodiment of the present invention. [Figure 4B] FIG. 1B is a side cutaway view of one embodiment of a valve support. [Figure 5] FIG. 1 is a partial cutaway side view of one embodiment of the present invention. [Figure 6] FIG. 1 is a partial cutaway side view of one embodiment of the present invention. [Figure 7] FIG. 1 is a partial cutaway side view of one embodiment of the present invention. [Figure 8] FIG. 1 is a partial cutaway side view of one embodiment of the present invention. [Figure 9] FIG. 1 is a partial cutaway side view of one embodiment of the present invention. [Figure 10] FIG. 1 is a partial cutaway side view of one embodiment of the present invention. [Figure 11A] FIG. 1 is a partial cutaway side view of one embodiment of the present invention. [Figure 11B] FIG. 1 is a top cutaway view of one embodiment of the present invention. [Figure 12] FIG. 1 is a side cutaway view of one embodiment of the present invention. [Figure 13] FIG. 1 is a side cutaway view of one embodiment of the present invention. [Figure 14] FIG. 1 is a side cutaway view of one embodiment of the present invention. [Figure 15] FIG. 1 is a side cutaway view of one embodiment of the present invention. [Figure 16] FIG. 1 is a side view of one embodiment of the present invention. [Figure 17] FIG. 1 is a side view of one embodiment of the present invention. [Figure 18A] 1 illustrates a cutaway view of one embodiment of a mandrel of the present invention. [Figure 18B] FIG. 1 is a side view of one embodiment of the present invention. [Figure 19A] 1 illustrates a cutaway view of one embodiment of a mandrel of the present invention. [Figure 19B] 1 shows a side view of one embodiment of the present invention. [Figure 20A] 1 illustrates a cutaway view of one embodiment of a mandrel of the present invention. [Figure 20B] FIG. 1 is a side view of one embodiment of the present invention. [Figure 21] FIG. 1 is a side view of one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Various embodiments of the present invention comprise a prosthetic heart valve fixation solution that combines improved PVL mitigation with improved sealing and / or apposition between the implanted device and the heart chamber tissue.

[0025] The present invention will be described in the context of exemplary single-chamber expansion and implantation device configurations, including specific exemplary embodiments such as those shown in Figures 4A-11B and 16-17. However, as noted above, various embodiments of the present invention extend to implantable prosthetic heart valve devices generally, including, but not limited to, one- and / or two-chamber solutions. Furthermore, various embodiments of the present invention will be described as relating to prosthetic mitral valve devices. However, it will be readily understood by those skilled in the art that these embodiments may be applied to supplement and / or replace heart valve function generally.

[0026] 4A-6 , an exemplary embodiment of a collapsible, expandable retention structure 10 is shown, comprising an expandable stent frame 12 or other expandable material, such as a wire mesh and / or shape-memory metal or polymer, or an expandable, collapsible web or equivalent comprising interconnected cells, as known in the art. The retention structure 10 is preferably biased to expand to achieve an expanded state from a collapsed state, although other collapse-to-expansion mechanisms may also be used. Furthermore, the retention structure 10 may comprise a base portion 20 formed from the expandable stent frame 12 or equivalent, and thus capable of achieving multiple expansion states due to the natural movement of the heart chamber walls and valve annulus, including portions of the upper annular surface and / or medial throat of the annulus located between the upper annular surface or floor of the exemplary left atrium and left ventricle.

[0027] Base portion 20 includes a valve support 30 that is integrally formed with, operably engaged to, or otherwise attached to the base portion, and that includes an outer surface 22 and an inner surface 24. Valve support 30 includes an inner surface 32 and an outer surface 34, and valve support 30 is adapted to substantially align with a target valve annulus and permit unidirectional antegrade blood flow while preventing retrograde blood flow as a result of prosthetic valve leaflets 36 disposed on inner surface 32 of valve support 30.

[0028] The valve support 30 may be disposed entirely or at least partially within the base portion 20, or in alternative embodiments, the valve support 30 may extend completely away from the base portion 20, with no portion of the valve support 30 within the base portion 20. Thus, as shown in FIG. 4A, the valve support 30 is disposed entirely within the base portion 20. FIG. 5 illustrates the valve support 30 extending almost completely outside the base portion 20. FIG. 6 illustrates the valve support 30 partially within the base portion 20 and also extending outside the base portion 20. FIG. 8 illustrates a variation of the valve support 30 of FIG. 4A in that the valve support 30 is integrally formed with the base portion 20.

[0029] Referring now to the exemplary boss structure 40 shown in FIG. 7 , the boss structure 40, if present, can be used to align the fixation structure 10 with the valve annulus and, in combination with the base portion 20, can assist in sealingly crimping the fixation structure 10 against a portion of the annulus, including the annular surface and the inner throat of the annulus through which the boss 40 extends. The boss 40 can be attached to or integrally formed with the base portion 20, as shown, and can be used in combination with any of the structures described herein, including those that align with and / or effectively extend through a flow channel defined within the valve support 30. In this sense, the boss 40 is similar to the extended valve support 30 of FIG. 6 , except that the boss 40 does not support a prosthetic leaflet therein. In other embodiments, the valve support 30 and / or portions of the fixation structure, including the boss 40, can extend downstream in the antegrade direction away from the superior surface of the annulus and into the inner throat of the annulus. In some cases, the structure may extend inferiorly to pin the native valve leaflets. In other cases, the structure may extend down into the annulus but stop short of pinning the native leaflets.

[0030] Other variations of prosthetic valve devices are known in the art and would also benefit from variations of the present invention.

[0031] To help prevent PVL, it is known to cover at least a portion (usually the lower outer portion) of the fixation frame for a prosthetic heart valve with some kind of fabric or tissue. Known embodiments form bunchings or the like of covering material to form a seal against PVL. However, these solutions do not adequately address fit and / or crimping issues that arise from annular calcification and / or variations and variations in the annular environment.

[0032] Thus, with reference to the figures, the outer surface 22 of the base may be at least partially covered by a skirt S formed from or including a material M that conforms and seals against a portion of the atrial wall and / or upper annular surface. In some embodiments as shown, a portion of the anchoring structure 10 and / or valve support 30 may extend below the annular surface a distance within the annular throat, i.e., toward the native valve leaflets, and at least a portion of the anchoring structure 10 and / or valve support 30 may be covered by material M.

[0033] In some embodiments, the material M can seal with at least a portion of a circumferential region of the wall encompassing the left atrial appendage (LAA) in an exemplary left atrium to seal the LAA.

[0034] Material M may comprise a substance or compound that is hydrophilic, and the skirt of proximal portion 20 may be formed, in whole or in part, at least from material M, and may be hydrophilic. In this case, the hydrophilic skirt may absorb water from the patient's blood and expand or swell to provide a tight seal and / or crimp between proximal portion 20 and the relevant region of the heart chamber, thereby acting as a barrier to retrograde blood flow upon implantation and reducing and / or preventing PVL.

[0035] Hydrophilic material M can comprise a hydrophilic gel and / or hydrophilic polymer that can be selected, for example, with one swelling modulus or two or more swelling moduli to help ensure that the swollen material M and / or hydrophilic skirt comprising material M swells to the "right" size and further ensure that the swelling process occurs slowly and gently, allowing the device to be properly positioned within the cardiac chamber before substantial swelling occurs. An exemplary hydrophilic hydrogel can include poly(vinyl alcohol) (PVA).

[0036] Hydrogel embodiments of Material M may comprise hydrophilic polymers that are chemically, physically, and / or ionically crosslinked to form a matrix that swells in water. The degree of swelling of the hydrogel in water is determined by the balance between the free energy of polymer / solvent mixing, ionic interactions, and elastic forces, and is influenced by the degree of crosslinking and the chemical nature of the polymer. The degree of swelling, in turn, determines the mesh size of the hydrogel. Hydrophilic hydrogels and / or polymers may be temperature- and / or pH-responsive. Some, such as chitosan and alginate, are naturally occurring and offer both natural hydrophilicity and biocompatibility. Additionally, swelling may be initiated by mechanical means, such as agitation.

[0037] Other hydrophilic materials, such as hydrophilic metals, may comprise part of the anchoring structure 10 .

[0038] The hydrophilic material M may be encapsulated within easily destructible, dissolvable, or biodegradable or bioerodible nanoparticles, such that upon destruction of the nanoparticles, the hydrophilic material M is exposed to water and initiates the swelling process, in which case the prosthetic heart valve device is positioned and implanted before substantial swelling occurs.

[0039] The skirt S can comprise two layers of material, an inner layer I attached to the outer surface 22 of the base portion 20 and an outer layer O, which form a pocket or series of pockets P. A hydrophilic material M can be disposed, attached, or incorporated into designed areas within the pocket or series of pockets to facilitate swelling at the interface area between the dilation device and the patient's anatomy most vulnerable to PVL. For example, a pocket or multiple pockets can be disposed around and / or at least partially upwardly from the bottom surface of the base portion 20. An exemplary skirt S comprising pockets P is shown in the drawings, with particular reference to FIGS. 12 through 15. As shown in the figures, sub-pockets P' can be provided within the two-layer skirt to individually position hydrophilic material M in areas particularly susceptible or vulnerable to insufficient crimping and / or PVL, as shown in FIGS. 13 through 15. As shown in the figures, at least some of the sub-pockets P' can be shaped and configured to swell radially outward to, among other things, seal and possibly partially fill the left atrial appendage or LAA.

[0040] In embodiments such as those shown in Figures 5-7 and 15-17, the valve support 30 or boss 40 or other structure extends at least partially outward from the base portion 20, and a skirt S can cover at least a portion of the outer surface 34 of the valve support 30 and have a hydrophilic material M integrated into or comprising the skirt S, including, but not limited to, the pocket P and / or sub-pocket P' formed as described above.

[0041] In embodiments comprising a boss structure or other extension into the medial throat of the annulus, a pocket P and / or sub-pocket P' comprising material M may be formed between the boss structure and base portion 20 to swellably close any gaps between the device and the patient's anatomy. This is best shown in FIG.

[0042] Alternatively, in embodiments comprising encapsulated hydrophilic material M, the nanoparticles or capsules may be integrated into, incorporated into, coated onto, attached or glued to the skirt, at least in the weakened regions of the PVL described above. Even more alternatively, the nanoparticles or capsules carrying hydrophilic material M may be attached or glued or coated onto or integrated into the skirt.

[0043] Thus, in certain embodiments, pockets P formed in the skirt S are not required, and the skirt S can be formed from or comprise a single layer of material, with the hydrophilic material M attached or adhered or coated thereon or incorporated therein, either encapsulated or non-encapsulated. Figures 16 and 17 show an exemplary single-layer skirt S including the hydrophilic material M.

[0044] In an alternative embodiment, a portion of the fixation structure 10 may be at least partially formed from a hydrophilic material M and may be covered or overcoated with a thin film of a biodegradable, dissolvable, bioerodible, and / or bioabsorbable material to retard solute interaction and resulting swelling with the hydrophilic material M. For example, without limitation, the boss structure 40, or other extension into the medial throat of the annulus, may comprise a hydrophilic polymer that swells upon contact with a solute, e.g., water in the blood. In this embodiment, a thin biodegradable, bioerodible, and / or bioabsorbable coating layer may be applied over the boss structure 40 to appropriately delay swelling until implantation is achieved. The outer portion of the boss structure 40, i.e., the portion juxtaposed by and / or within the annulus and / or medial throat of the annulus, may comprise a hydrophilic material, e.g., a polymer, such that only the outer portion of the boss structure 40 swells in response to solute contact, while the dimensions of the inner boss structure 40 remain unchanged. Other regions of the anchoring structure 10 may also be formed from a hydrophilic material M, such as a polymer, for example key struts or cells of the anchoring structure 10, and may comprise a hydrophilic polymer that swells upon contact with solute.

[0045] Additionally, a portion of the fixation structure 10 may also comprise a skirt S comprising a thin film of hydrophilic material M that may be temporarily covered or overcoated during delivery and implantation by a biodegradable, dissolvable, bioerodible and / or bioabsorbable thin film layer as described above.

[0046] Additionally, nanoparticles encapsulating the hydrophilic material M described above may be adhered or coated to a portion of the anchoring structure 10 to provide a skirt S. These nanoparticles may be overcoated with a thin biodegradable, dissolvable, bioerodible and / or bioabsorbable film to ensure adhesion to the anchoring structure during delivery and implantation.

[0047] Each of the above possible embodiments for implementing a hydrophilic skirt comprising or incorporating a hydrophilic material M can be used to cover portions of various configurations of a prosthetic heart valve device. Exemplary embodiments in which the valve support 30 is formed from or otherwise integrated or attached to the base portion 20 are shown in Figures 4A, 8-10, 11A, and 16-17. In this case, a hydrophilic skirt S comprising the above-described hydrophilic material M can cover the outer surface 22 of the base portion 20, extend to cover the bottom of the base portion 20, and extend further up within the base portion 20 to cover the inner surface 32 of the valve support 30.

[0048] In some embodiments, sealing of the left atrial appendage (LAA) may be the goal. In these cases, as shown in FIG. 15 , a hydrophilic skirt S comprising hydrophilic material M can include a reserve pocket 100 of hydrophilic material M in the region of the LAA, and upon implantation, the hydrophilic material M swells to expand the pocket 100 and cover and / or fill the LAA. The reserve of hydrophilic material M can include a ring or gasket 102 of material M around the skirt S so that positioning of the LAA is achieved regardless of the rotational position of the implanted fixation structure 10. Alternatively, a specific pocket 102 may be provided, as described above, positioned in the LAA for swelling sealing and / or filling of the LAA. The reserve of hydrophilic material M can be formed according to various embodiments discussed herein, including pockets and / or nanoparticles and / or coatings.

[0049] Thus, in general, improved sealing and / or crimping may be achieved by including hydrophilic material M at one or more locations on the anchoring structure 10. The hydrophilic material M may be associated with, integrated into, or incorporated into the skirt S, but this is but one embodiment. Nanoparticles, when used, may comprise readily destructible and / or biodegradable, bioerodible, or dissolvable materials to provide the desired delay in exposing the hydrophilic material M to blood.

[0050] 4A-8, it should be noted that, in general, the illustrated embodiments are substantially symmetrical about a central axis A (eg, as shown in FIG. 4A).

[0051] As noted above, the left atrium is not perfectly symmetrical. More specifically, the left atrium includes an anterior-medial tilt. This anterior-medial tilt can potentially lead to migration of the implantable device as it attempts to adapt and / or conform to the shape of the left atrial cavity. This asymmetry is best illustrated in Figures 1 and 18-20.

[0052] The devices shown in Figures 4A-11 and 16-17 comprise stent frames of particular shapes that are achieved by using a mandrel having a desired shape, as will be appreciated by those skilled in the art. The stent frame material is stretched over the mandrel and processed by known means to achieve the desired stent frame shape.

[0053] The stent mandrel of Figure 18 is essentially a mandrel that results in the symmetrical stent frame shape of, for example, Figure 4A. The mandrel has anterior and posterior sections of substantially equal size, each of which has substantially the same shape. The "chimney" that forms the valve support of the prosthetic heart valve device is centered between the anterior and posterior sections, and the resulting valve support is positioned to overlie the valve annulus when implanted. As shown, a top structure can be provided, which may include a ring to help distribute forces over a larger area. The mandrel is shown as being oversized for the atrium; this may be required to provide a slightly oversized stent frame that, when expanded, creates a strong friction fit within the heart chamber.

[0054] Thus, the device of 18B comprises a central axis A having a posterior portion and an anterior portion, and the valve support and apex structure are disposed symmetrically about axis A, such that the apex structure and valve support are effectively aligned along axis A. The apex structure may or may not be present in various embodiments.

[0055] Figure 19A provides an alternative solution, in which the mandrel has an asymmetric "bean" shape and is positioned so that the "chimney" that creates the valve support within the resulting stent frame is above the valve annulus when the device is implanted, as in Figure 18A. As shown in Figure 19A, the posterior portion or portions of the mandrel are smaller than the anterior portion or portions. Furthermore, the anterior portion or portions are larger than the anterior portion of Figure 18A, and the posterior portion or portions are smaller than the posterior portion of Figure 18A. Figure 19B provides an exemplary device resulting from processing with the mandrel of Figure 19A.

[0056] As can be seen, the arrangement of FIG. 19A allows the anterior portion to accommodate or engage more of the left atrium than the arrangement of FIG. 18A while still maintaining a fluid flow path through the valve support, into the annulus, and through the native valve leaflets.

[0057] The top structure of FIG. 19B may be optional and is shown here shifted to a forward portion away from axis A to aid in force transmission and / or distribution.

[0058] Figure 20A includes the same mandrel as Figure 18A, with one difference being that the posterior base portion of the mandrel defines a radially extending lip. Thus, the resulting device shown in Figure 20B includes a radially extending lip that, when expanded, engages the left atrium on the posterior side of the chamber with a higher frictional grip than the device in Figure 18B, thus assisting in shifting due to atrial asymmetry after implantation. The apex structure is shown aligned with axis A, as in Figure 18B.

[0059] 19B and 20B can be provided, where a portion of the frame is asymmetrical, a posterior lip structure is provided, an apex structure is offset from axis A, and the valve support is aligned with axis A and positioned to overlie the valve annulus when implanted, as shown in Figure 21. Alternative configurations may include no apex structure or may include an apex structure aligned with axis A.

[0060] In all cases, the "chimney" and resulting valve support are positioned perpendicular to the base of the stent. As further noted above, the length of the "chimney" and resulting valve support may vary and may or may not be positioned completely within the stent framework.

[0061] In any of the described embodiments, the anterior portion of the stent frame may comprise a hydrophilic material (e.g., a hydrophilic metal) that expands upon exposure to a liquid (e.g., blood). The hydrophilic metal may be adapted to expand only radially outward to enhance conformance of the anterior portion to the wall of a heart chamber, e.g., the left atrium, anteriorly. Alternatively, at least a portion of the outer portion of the anterior portion may be coated with a hydrophilic material that expands radially outward to achieve better conformance with the anterior atrial wall. Alternatively, some or all of the outer stent frame may include a hydrophilic material to enhance expanded conformance (and engagement) with the heart chamber wall. As described above, the hydrophilic material may be thinly coated and / or encased in nanoparticles to delay hydrophilic expansion until the device is released from the delivery catheter and at least temporarily positioned in the heart chamber.

[0062] Similarly, the trailing lip of the exemplary stent frame of FIG. 20B may be formed and / or defined within the device as a result of the stent frame taking the shape of a mandrel containing the lip structure. In this case, the lip is provided on the stent during delivery and implantation. Alternatively, the stent frame at the desired lip location may comprise a hydrophilic material, such as a hydrophilic metal, or may be coated with a hydrophilic material. The hydrophilic material may be a metal, a coating, or a thin film. An alternative coating may comprise a hydrophilic material encased in nanoparticles to allow the lip to form only after the device is deployed and implanted. Alternatively, the lip may be formed by a hydrophilic pocket, as described above.

[0063] As shown, the lip is not symmetrical around the device, but is effectively a raised ridge or lip that extends radially outward from a portion of the base of the prosthetic heart valve device. Alternative lip structures may surround the entire base structure such that the lip is effectively symmetrical.

[0064] Additionally, a raised lip may be defined on a portion of the base portion that extends slightly downward into the annulus when implanted.

[0065] Further alternatively, a raised lip may be defined on or near a portion of the base portion that engages the superior surface of the annulus, a structure sometimes referred to as an annular ring.

[0066] Thus, the raised lip can increase the oversize of the base portion to improve crimping, fit, and prevent shift migration during implantation.

[0067] The asymmetric structures described herein require directional delivery techniques to achieve proper positioning of the device prior to implantation. For example, the asymmetric stent-frame embodiment of Figure 19B requires that the posterior portion be positioned against the posterior wall of the left atrium. Similarly, the posterior lip portion of Figure 20B must be delivered and / or positioned so that the lip is adjacent to the posterior wall of the left atrium.

[0068] Thus, the lip structure may be provided as a result of processing and machining with a mandrel, as shown in the figures. To aid in positioning and implantation, in some cases, the lip may be smaller than desired, but may be adapted to expand with a hydrophilic expansion, as described above, to constrict expansion of the device against the posterior wall. In other cases, the lip structure may be formed entirely from a hydrophilic structure, as described above. In this case, the lip structure begins to form only after delivery of the prosthetic valve device into a wet heart chamber, which can aid in keeping the delivery profile as low as possible and in recapture and repositioning.

[0069] The hydrophilic expansion technique described herein can be used alone or in combination with a mandrel to create and / or modify the shape of the stent frame and / or lip structure, and can further be used to create lip structures.

[0070] The improved prosthetic heart valve devices described herein provide better crimping and conforming to the heart chamber, e.g., the left atrium, wall and annulus, thus (1) mitigating migration of the implanted device as a result of asymmetry of the heart chamber, (2) improving the seal against associated tissue, and further aiding in the prevention of PVL.

[0071] The description of the invention and its applications set forth herein is illustrative and is not intended to limit the scope of the invention. Features of various embodiments may be combined with other embodiments within the contemplation of the invention. Variations and modifications of the embodiments disclosed herein are possible, and practical substitutes and equivalents of the various elements of the embodiments will be apparent to those skilled in the art upon review of this patent document. These and other variations and modifications of the embodiments disclosed herein can be made without departing from the scope and spirit of the invention.

Claims

1. 1. A device for extended implantation into the left atrium of a patient's heart, comprising: an expandable stent frame having a posterior portion and an anterior portion; A base portion; a valve support configured to support at least one prosthetic valve; a top structure comprising a ring structure disposed in the forward portion; Equipped with the rear portion and the front portion are asymmetrically shaped with respect to an axis extending between the rear portion and the front portion; the ring structure is offset from the axis; the rear portion is smaller than the front portion; A device for extended implantation into the left atrium of a patient's heart.

2. The device of claim 1 , wherein the shaft extends through the valve support.

3. The device of claim 1 , wherein at least a portion of the front portion comprises a hydrophilic material.

4. The device of claim 3 , wherein the front portion comprises a hydrophilic metal.

5. The device of claim 3 , wherein the anterior portion is configured to expand radially when wetted.

6. 10. The device of claim 1, wherein the device is delivered transseptally and directionally to position and / or deliver and / or implant the posterior portion against the posterior wall of the left atrium.

7. The device described in claim 2, wherein the axis is perpendicular to a plane defined by the bottom surface of the base portion.

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