Conformal surgical heart valve sewing rings

Abstract

Contoured or conformal sewing rings for surgical prosthetic heart valves adapted for implant at a native tricuspid annulus. The sewing ring may be substantially D-shaped with one flat side defined by corners. The sewing ring may have an elastomeric inner core surrounded by biocompatible cloth. The inner core may be molded to have inner walls dividing the volume of the inner core into cells that open to both inflow and outflow faces thereof. The biocompatible cloth may be substantially incompressible around most of the periphery of the inner core except for on the flat side which is a highly compressible cloth so that no attachment members need be utilized in that region. By aligning the flat side with highly compressible cloth with the septal aspect of the tricuspid annulus, the lack of attachment members such as sutures helps prevent damage to the conduction system of the heart. Another sewing ring may have an axial bulge projecting in an outflow direction and adapted to conform to an irregular tricuspid annulus. A still further shape may be generally ovoid with two elongated lips extending outward from a circular inner wall along a long axis of the sewing ring.

Description

CONFORMAL SURGICAL HEART VALVE SEWING RINGSRELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Patent Application No. 63 / 626,637, filed January 30, 2024, the entire disclosure of which is incorporated by reference for all purposes.TECHNICAL FIELD

[0002] The present application relates generally to implantable prosthetic heart valves and, more particularly, to contoured or conformal sew ing rings for particular placements.BACKGROUND

[0003] In vertebrate animals, the heart is a hollow muscular organ having four pumping chambers: the left and right atria and the left and right ventricles, each provided with its own one-way valve. The natural heart valves are identified as the aortic, mitral (or bicuspid), tricuspid and pulmonary7, and each has flexible leaflets that coapt against each other to prevent reverse flow. Heart valve disease continues to be a significant cause of morbidity and mortality, resulting from a number of ailments including rheumatic fever and birth defects. Recent statistics show that valvular heart disease is responsible for nearly 20,000 deaths each year in the United States, and is a contributing factor in approximately 42,000 deaths. Currently, the primary treatment of aortic valve disease is valve replacement. Worldwide, there are approximately 300,000 heart valve replacement surgeries performed annually.

[0004] The most common type of surgical prosthetic heart valve is a tissue-type or “bioprosthetic” valve havi ng flexible leaflets supported by a base structure and projecting into the flow stream that function much like those of a natural human heart valve and imitate their natural flexing action to coapt against each other and ensure one-way blood flow. In tissue-type valves fluid occluding surfaces may be provided by a whole xenograft valve (e.y., porcine), a composite porcine valve where the non-coronary cusps of three different porcine valves are sewn together so as to avoid the anatomical variations in different parts of a whole valve, or a plurality of xenograft leaflets e.g., bovine or porcine pericardium). Synthetic leaflets have been proposed, and thus the term “flexible leaflet valve” refers to both natural and artificial “tissue-type” valves. Components of the valve are usually assembled with one or more biocompatible fabric (c.c / ., Dacron® polyester) coverings, and a fabric-covered sewing ring is provided on the inflow end of the peripheral support structure. One example of a flexible leaflet valve is disclosed in U.S. Patent No. 6,585,766 to Huynh, et al., the disclosure of which is hereby expressly incorporated by reference.

[0005] In most bioprosthetic-type valves, an annular metallic or polymeric structure supports the flexible leaflets, which extend therefrom. Two or more flexible leaflets aremounted within a peripheral support structure that usually includes posts or commissures extending in the outflow direction to mimic natural fibrous commissures in the native annulus. One such support is an elastic “support frame,” sometimes called a “wireform” or “stent,” w hich has a plurality (typically three) of large radius cusps supporting the cusp region of the flexible leaflets (e.g., either a whole xenograft valve or three separate leaflets). Other “support frame” constructions exhibit sheet-like tubular shapes but still define commissures and cusps on their outflow’ ends, such as shown in U.S. Patent No. 5,984,973 to Gerard, et al., the disclosure of w hich is hereby expressly incorporated by reference.

[0006] Surgical prosthetic heart valves contrast with transcatheter valves in that they are not collapsible and must be implanted using traditional open-heart techniques with the heart stopped and the patient on cardiopulmonary bypass. Transcatheter valves collapse and are delivered through catheters or sheaths while the heart is beating. Surgical prosthetic heart valves attach to the patient’s fibrous heart valve annulus, with or without the leaflets being present.

[0007] Replacement surgical heart valves, whether mechanical or bioprosthetic, typically utilize sewing rings or cuffs for attachment of the valve within the annulus. Serving rings are generally composed of silicone, expanded PTFE, woven polyester fabric (e.g., polyethylene terephthalate or polyester), silk, polypropylene, and other fiber or fabric materials or combinations of these materials. The most common locations at which prosthetic heart valves are implanted are the aortic and mitral valves associated with the left ventricle, w hich generates the higher pressures of the tw o ventricles. However, more and more tricuspid and pul monary valve replacements are being studied as alternatives to simple repair with an annuloplasty ring, for example. U.S. Patent No. 7,776,084 to Johnson discloses a prosthetic mitral heart valve having a sewing ring that better matches the mitral valve annulus by having two upward rises formed in a waffle-like silicone structure covered with fabric.

[0008] In general, sewing rings for surgical heart valves have performed adequately, at least relative to other complications associated with prosthetic valve implantation. However, there remains a need for improved sewing rings that better conform to the particular annulus.SUMMARY

[0009] Disclosed here are contoured or conformal sewing rings for surgical prosthetic heart valves adapted for implant at a native tricuspid annulus. The sewing ring may be substantially D-shaped with one flat side defined by corners. The sewing ring may have an elastomeric inner core surrounded by biocompatible cloth. The inner core may be molded to have inner w alls dividing the volume of the inner core into cells that open to both inflow- andoutflow faces thereof. The biocompatible cloth may be substantially incompressible around most of the periphery of the inner core except for on the flat side which is a highly compressible cloth so that no attachment members need be utilized in that region. By aligning the flat side with highly compressible cloth w ith the septal aspect of the tricuspid annulus, the lack of attachment members such as sutures helps prevent damage to the conduction system of the heart. Another sewing ring may be generally ovoid with two elongated lips extending outward from a circular inner wall along a long axis of the sewing ring. A still further shape may have an axial bulge projecting in an outflow direction and adapted to conform to an irregular tricuspid annulus.

[0010] The various prosthetic heart valves having conformal sewing rings disclosed herein are adapted for implant at a native tricuspid annulus. The tricuspid annulus defines an asymmetric ovoid shape as seen looking at an inflow- side of the tricuspid valve circumscribing the following anatomical landmarks of the native tricuspid valve as seen in series in a clockwise direction: an antero-septal commissure, an anterior leaflet on an anterior side, an antero-posterior commissure, a posterior leaflet on a posterior side, a postero-septal commissure, and a septal leaflet on a septal side. The native tricuspid valve further has a long dimension extending approximately from the antero-septal commissure to the postero-septal commissure with the septal leaflet extending therebetween. The septal leaflet is located inward of electrical structure of the heart including an atrioventricular node (AV node) and a bundle of His extending clockw ise the AV node, the AV node being in turn located clockwise adjacent an apex of a triangle of Koch that is formed by the septal side, an ostium of the coronary sinus, and the tendon of Todaro.

[0011] The prosthetic heart valves each have a cloth-covered valve stent defining an orifice about a central axis, the valve stent having an inflow- end and outflow commissure posts extending in an outflow direction away from the inflow^ end, and w herein inflow is down and outflow is up. A plurality of flexible leaflets are attached to the valve stent and extend within the valve stent orifice to enable one-way flow- regulation of blood through the orifice.

[0012] A first exemplary prosthetic heart valve has a suture-permeable sewing ring attached around the inflow end of the valve stent, the sewing ring defining a circular inner wall and a substantially D-shaped outer periphery with one flat side being flatter than a remaining convex periphery. The sewing ring may be formed by an elastomeric inner core covered in cloth, and the inner core may be molded to have walls dividing a volume of the inner core into cells open at least toward an outflow face of the inner core. The inner core w-alls may form cells open toward both an inflow face and the outflow face of the inner core. The cloth covering the inner core may be mostly a smooth and relatively incompressiblebiocompatible fabric except for on the flat side on which is provided a highly compressible plush fabric. The plush fabric may be provided just on an outer periphery' of the sewing ring, without extending radially inw ard to the valve stent. The plush fabric may be provided just within a middle portion of the flat side with outer corners of the flat side having the smooth and relatively’ incompressible biocompatible fabric. The sewing ring may be formed by a rolled or folded cloth or felt which is smooth and relatively incompressible except for on the flat side which is a highly’ compressible plush fabric. The plush fabric may be provided just on an outer periphery of the sewing ring, without extending radially inward to the valve stent. The plush fabric may be provided just within a middle portion of the flat side with outer corners of the flat side having the rolled or folded cloth or felt. The sewing ring may define a flat annular shape with no up or down portions.

[0013] A second exemplary? prosthetic heart valve has a suture-permeable sewing ring attached around the inflow? end of the valve stent, the sewing ring defining a circular inner wall and a generally? ovoid outer periphery? with a long axis and a short axis that forms elongated lips projecting from the inner wall outw?ard along the long axis that are longer than portions extending from the inner wall outward along the short axis. The sewing ring may be formed by? an elastomeric inner core covered in cloth, and the inner core is molded to have walls dividing a volume of the inner core into cells open tow?ard both an inflow face and an outflow? face of the inner core. The inner core may have a frusto-conical outer profile with generally axially-oriented inner walls describing a circle to receive the cloth-covered valve stent. An outer edge may? form an outermost extent of the inner core, w herein the inner walls are interrupted by three arcuate ledges sized and shaped to receive inflow cusps of the cloth- covered valve stent. The inner core may have angled webbing separating the cells and formed between radial ribs open to the outflow face from the cells formed betw een radial ribs open toward the inflow? face. The elongated lips may include a larger lip having a radial width W and a smaller lip having a smaller width w that is between about 50-75% of the width W. The outer peripheiy may be convex except for along one flat side intersecting the short axis.

[0014] A third exemplary prosthetic heart valve has a suture-permeable sewing ring attached around the inflow end of the valve stent, the sewing ring defining a flat annular shape around a majority of a periphery? thereof with an axial bulge extending in the outflow direction on one side thereof, and the inner core is molded to have w alls dividing a volume of the inner core into cells open tow?ard both an inflow? face and an outflow? face of the inner core. The angular extent of the axial bulge may? be between 80-100°. The axial bulge may rise up gradually from an otherwise flat outflow? face. The axial bulge may? have both a solid outer wall and a solid inner wall. The inner core may have angled w?ebbing separating thecells and formed between radial ribs open to the outflow face from the cells formed betw een radial ribs open toward the inflow face.

[0015] A fourth exemplary prosthetic heart valve has a suture-permeable sewing ring attached around the inflow end of the valve stent, the sewing ring is formed by an elastomeric inner core covered in cloth, and the inner core is molded to have walls dividing a volume of the inner core into cells open toward both an inflow face and an outflow face of the inner core.

[0016] A method of implanting a prosthetic heart valve having a conformal sewing ring at a native tricuspid annulus, comprises: providing a prosthetic heart valve having: a cloth-covered valve stent defining an orifice about a central axis, the stent having an inflow end and outflow commissure posts extending in an outflow direction away from the inflow end, and wherein inflow is down and outflow is up; a plurality of flexible leaflets are attached to the valve stent and extend within the valve stent orifice to enable one-way flow regulation of blood through the orifice; and a suture-permeable sewing ring attached around the inflow end of the valve stent, the sewing ring having a substantially D-shape periphery with one flat side being flatter than the remaining convex periphery , and wherein an exterior of the sewing ring is a smooth and relatively incompressible biocompatible fabric except for on the flat side which is a highly compressible cloth; stopping the patient’s heart and providing an access pathway to the tricuspid annulus on the atrial side; advancing the heart valve into contact with the tricuspid annulus; and securing the sewing ring to the annulus using attachment members around the D- shape periphery except for a mid-portion of the flat side where there are no attachment members and no approximating forces holding the sewing ring to the annulus in that area.

[0017] In the method, the sewing ring may be formed by an elastomeric inner core covered in cloth, and the inner core is molded to have w alls dividing a volume of the inner core into cells open tow ard both an inflow face and an outflow face of the inner core. The sewing ring may be formed by a rolled or folded cloth. No sutures or attachment means may be positioned within 2 mm of the Bundle of His or the AV Node.

[0018] A further understanding of the nature and advantages of the invention will become apparent by reference to the remaining portions of the specification and drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Features and advantages of the present invention will become appreciated as the same become better understood with reference to the specification, claims, and appended drawings wherein:

[0020] Figure 1 is a perspective view of a prosthetic heart valve having a first exemplary fabric-covered conformal sewing ring of the present application;

[0021] Figure 2 is an exploded view' of Figure 1 illustrating a subassembly of three flexible leaflets supported by a peripheral stent and the conformal sewing ring;

[0022] Figure 3A is a first peripheral stent or wireform, Figure 3B is a second peripheral stent made of polymeric material, and Figure 3C is a third peripheral stent made of a metal;

[0023] Figure 4 shows three flexible leaflets in their relative closed or coapting positions within the prosthetic heart valve;

[0024] Figure 5 is a perspective view of an inner core of the exemplaiy conformal sewing ring of Figure 1 having a somewhat D-shape with one flat side;

[0025] Figures 6A-6D are perspective and orthogonal views of the D-shaped inner core of the sewing ring of Figure 5;

[0026] Figure 7 is an outflow plan view of the D-shaped inner core;

[0027] Figure 8A is a radial sectional view' across the D-shaped inner core taken along diagonal line 8A-8A of Figure 7, and Figures 8B and 8C are enlargements of the opposite side walls;

[0028] Figures 9A and 9B are outflow and inflow perspective views of an alternative inner core for a conformal sewing ring of the present application having waffle-like cells on both upper and lower faces, Figure 9C is a partial cutaw ay view of Figure 9A, and Figures 9D and 9E are enlargements of sections through the opposite side walls thereof;

[0029] Figures 10A and 10B are outflow' and inflow' perspective views of an inner core for a still further conformal sewing ring having a somewhat D-shape with one flat side and waffle-like cells on both upper and low'er faces, Figure 10C is an outflow' plan view' thereof, Figure 10D is another outflow’ perspective view, Figure 10E is a partial cutaway view of Figure 10A, and Figures 10F and 10G are enlargements of sections through the opposite side walls thereof;

[0030] Figures 11A and 11B are outflow perspective views of still another inner core for a conformal sewing ring having opposed outward lips on opposite longitudinal sides and waffle-like cells on both upper and lower faces, and Figures 11C and 11D are inflow’ and outflow plan views thereof;

[0031] Figure 12A is an outflow perspective view of another alternative inner core for a conformal sewing ring having an upward rise on one side and waffle-like cells on both upper and lower faces, and Figure 12B is a side elevational view illustrating the extent of the upward rise;

[0032] Figure 13 is a schematic plan view of the tricuspid annulus w ith typical orientation directions noted as seen from the inflow side and indicating a position of the aortic valve alongside within the heart;

[0033] Figure 14 is a plan view of the native tricuspid valve and surrounding anatomy from the inflow side;

[0034] Figure 15 is a plan view of the native tricuspid valve and surrounding anatomy from the inflow side with just the sewing ring of the valve from Figure 1 sewn thereto in an implant position;

[0035] Figure 16 is another plan view of the native tricuspid valve and annulus with a heart valve having the sewing ring of Figures 11A-11D sewn thereto in an implant position;

[0036] Figure 17A is a schematic sectional view of the heart showing the atrioventricular valves between the atria and the ventricles, while Figure 17B shows a step in advancing a surgical prosthetic heart valve to the tricuspid annulus during implantation thereof;

[0037] Figure 17C shows the prosthetic heart valve surgically implanted at the tricuspid annulus, and Figure 17D is a view of an outflow end of the heart valve looking from the right ventricle along line 17D-17D in Figure 17C;

[0038] Figure 18 is an outflow7plan view of a surgical prosthetic heart valve of the present application having a conformal sewing ring;

[0039] Figure 19 is an outline of the heart valve of Figure 18 superimposed upon a tricuspid valve looking from the ventricular side;

[0040] Figure 20A is a perspective view of another surgical prosthetic heart valve having a conformal sewing ring without a fabric covering, and Figure 20B is an isolated perspective view of the inner core of the sewing ring;

[0041] Figure 21 is an outline of the heart valve of Figure 20A superimposed upon a tricuspid valve looking from the ventricular side;

[0042] Figure 22A is a schematic sectional view of the right side of the heart showing one common shape of the tricuspid annulus, and Figure 22B shows the prosthetic heart valve of Figure 20A surgically implanted at the tricuspid annulus;

[0043] Figure 23A is a perspective view of an inner core of another conformal sewing ring having a portion removed, and Figure 23B is a side elevational view of the inner core;

[0044] Figure 24 is an outline of a heart valve having the sewing ring of Figure 23A superimposed upon a tricuspid valve looking from the ventricular side;

[0045] Figures 25A and 25B are perspective and inflow plan views of a still further surgical prosthetic heart valve that show a conformal sewing ring having a plush fabric portion thereon; and

[0046] Figures 26A-26C illustrate a sequence of delivery of the heart valve of Figure 25A to a tricuspid annulus, and Figure 26D shows the implanted heart valve from the ventricular side.DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

[0047] The right ventricle and left ventricle are separated from the right atrium and left atrium, respectively, by the tricuspid valve and mitral valve; e.g., the atrioventricular valves. The septal walls extend between the right atrium and left atrium and also between the right ventricle and the left ventricle. The present specification and drawings provide aspects and features of the disclosure in the context of several embodiments of replacement heart valves, delivery systems and methods that are configured for use in the vasculature of a patient, such as for replacement of natural heart valves in a patient. Surgical valve replacement in the mitral or tricuspid annulus is a primary focus of the present application, but certain characteristics of the delivery systems described herein may equally be used for other valve implant locations, and thus the claims should not be constrained to mitral or tricuspid valve replacement unless expressly limited.

[0048] The anatomy of each different valve annulus is quite different from the other. The aortic annulus defines an undulating fibrous structure around substantially a circular ring to support the up-and-down shape of the cusps and commissures of the three generally similar native leaflets. The three leaflets attach along these anatomical landmarks, and prosthetic surgical heart valves often attempt to mimic the shape of the leaflets. Because the annulus has such a dramatic undulating shape, prosthetic aortic heart valves often have sewing rings that undulate to conform to the annulus at least partially. On the other hand, the mitral annulus has a somewhat fibrous linear anterior aspect across the septum of the heart from the aortic valve, but the posterior aspect, which defines the majority of the annulus, is relatively less fibrous and more muscular. Also, the posterior aspect is nearly oval-shaped such that the mitral annulus presents a malformed “D” shape during systolic ejection when the mitral valve is closed with the anterior side of the annulus moving out of the left ventricular outflow track to avoid obstructing the flow out of the left ventricle through theaortic valve while the posterior side of the annulus maintains its oval shape. The tricuspid valve, on the other hand, is an asymmetric tri-leaflet valve with no planes of symmetry' through an ovoid or generally egg-shaped annulus with a long axis and a short axis, and one long end wider than the other.

[0049] Atrioventricular (e.g., mitral and tricuspid) annuluses are contoured or three- dimensional, though somewhat less defined in the up-and-down axial or flow direction, as is the aortic annulus. Consequently, prosthetic heart valves for atrioventricular implant usually feature relatively flat sewing rings. U.S. Patent No. 7,776,084 discloses a prosthetic surgical mitral heart valve that includes two axial bumps or rises on the outflow side that enhance contact between the sew ing ring and the surrounding mitral annulus. The two bumps also lift an anterior side upw ard so as to tilt the entire valve away from the left ventricle wall to reduce the risk of contact between the posterior post of the valve and the endocardial surface of the left ventricle. Features of the '084 patent is incorporated into the MITRIS® mitral heart valve available from E w ards Lifesciences of Irvine, CA. The MITRIS valve is described as having a saddle-shaped sewing cuff that mimics the native mitral annulus. Annuloplasty rings used to repair atrioventricular valves, on the other hand, often have three-dimensional contours which attempt to match the anatomical annulus (see, e.g., U.S. Patent No. 7,367,991). Despite such three-dimensional constructs in mitral valves and atrioventricular annuloplasty rings, no valve has been developed for tricuspid replacement in this regard.

[0050] The present application thus discloses contoured sewing rings specifically designed, in one aspect, to minimize contact between the tricuspid valve struts and the endocardium of the right ventricle, while allowing natural motion of the right ventricular chamber. The design of sewing rings in tricuspid valves is a complicated by the fact that the annulus is highly dynamic. In other words, the annulus changes shape between the peak systolic and diastolic ejection phases of the cardiac cycle. Moreover, the aorta leading upward from the adjacent aortic valve intrudes upon the tricuspid valve, mostly below' the antero-septal commissure along the septal wall. Further, since the outflow' struts or commissure posts of the tricuspid valve project into the right ventricle, certain anatomical features are at risk of contact and abrasion, notably the septal wall and infundibular fold. Finally, the electrical system of the atrioventricular node is closely adjacent to the tricuspid annulus, as stated above. In short, anticipating all of these potential hazards w hen designing a sewing ring for the tricuspid valve is daunting.

[0051] Figure 1 is a perspective view' of a prosthetic surgical heart valve 20 having a first exemplary conformal sewing ring of the present application. Figure 2 is an exploded view of Figure 1 showing a leaflet subassembly 22 and a conformal sewing ring 24. The subassembly 22 comprises a peripheral support stent having three upstanding commissure posts 26alternating w ith three arcuate cusps 28. The peripheral support stent is fabric covered and supports three flexible leaflets 30 that are typically sewn thereto along the cusps 28. Each of the flexible leaflets 30 has a free edge 32 that extends into the middle of the heart valve 20 that provide occluding surfaces. More particularly, the leaflets are shown in a closed or coapting position w ith the free edges 32 coming together in the flow orifice to prevent backflow. Cyclic cardiac rhythms create downstream flow to open the leaflets 30, and thus the commissure posts 26 project in the downstream or outflow direction. The leaflets adjacent to the cusps 28 thus curve in the upstream or inflow direction.

[0052] As seen in Figure 2, the conformal sew ing ring 24 has a circular or annular profile 34 around a majority of its periphery, except for a relatively straightened or flat side 36 on one side thereof. The sewing ring 24 thus forms a somewhat of a D-shape. The radial dimension of the sewing ring 24 increases at the corners 38 of the flat side 36. More detail about the contours of the sewing ring will provided below , and will be understood that outer fabric covering generally conforms to these contours. The fabric covering provides strength when implanting the heart valve 20 using anchoring sutures.

[0053] The inner components of the exemplary heart valve 20 are shown in Figures 3-4. Figures 3A-3C show' three alternative possibilities for the peripheral stent used to support the flexible leaflets 30. Each of the peripheral stents has an arcuate cusp region to which cusp edges 40 (Figure 4) of the leaflets 30 may be attached.

[0054] Figure 3A is a first peripheral support stent or wireform 42 having upstanding commissure posts 44 pointed in the downstream direction at an outflow end of the stent alternating with arcuate cusps 46 that curve towards the upstream direction at an inflow end. The wireform 42 is typically made of a metallic alloy or super elastic metal such as Nitinol, and can be formed as a single continuous piece, or from a wire that is bent to shape and joined by a crimp (not shown). Injection molded polymer parts imitating the function of the wireform have also been employed.

[0055] Figure 3B is a second peripheral support stent 50 made of a polymeric material. The stent 50 includes an annular base ring 52 at an inflow' end and upstanding commissure posts 54. The base ring 52 has an upper edge which defines arcuate cusps to which the leaflet cusp edges 40 can be attached.

[0056] Figure 3C is a third peripheral support stent 60 made of a metal, such an alloy, Nitinol, or titanium. The stent 60 as an annular base ring 62 at an inflow' end joined to an undulating upper ring defining arcuate cusps 64 alternating with upstanding commissure posts 66. A plurality of axial struts 68 may connect the base ring 62 to the cusps 64.

[0057] Figure 4 shows the three flexible leaflets 30 in their relative positions within the prosthetic heart valve 20. As stated, the trefoil arrangement of the leaflets 30 may be secured to the fabric covering any of the three support stents 42, 50, or 60. Typical surgical heart valves have three separate flexible leaflets 30 that are then coupled together along with surrounding support structure, as shown, or the three flexible leaflets may be provided by an intact xenograft heart valve, such as from a pig. Separate leaflets 30 have been made of various xenograft materials, but bovine pericardial tissue is the most common. In some existing surgical valves, the three separate leaflets 30 are trimmed to size and joined together first before coupling to the remainder of the valve structure.

[0058] Figure 2 shows the leaflet subassembly 22 of a fabric-covered peripheral stent w ith commissure posts 26 and cusps 28 coupled with the three leaflets 30. Again, this may be separate leaflets 30, or a whole xenograft porcine valve, for example. The fabric covering the structural stent is used to anchor the edges of the leaflets using stitching, or the like. In many valves the peripheral stent has an undulating shape on its inflow7end wdth the arcuate cusps 28 separated by short gaps w here the commissure posts 26 rise up.

[0059] Figure 5 is a perspective view of an inner core 70 of the exemplary conformal sewing ring of Figure 1 showing a somewhat D-shape with a majority circular portion 34 and one flat side 36 flanked by corners 38. The inner core 70 is shown in greater detail in Figures 6-8, and has a generally axially-oriented inner wall 72 and an outer conical wall 74. The conical wall 74 angles outward in the downstream or outflow direction. As will be seen, the inner core 70 is desirably molded to have walls dividing a volume of the inner core into cells for greater compressibility. How ever, it should be noted that certain aspects of the sewing rings described herein may be attained without an inner core, by using just a rolled or folded cloth or felt. In this context, cloth refers to a broad category of woven fabrics made from various fibers, while felt is a non-woven fabric created by matting and pressing fibers together, resulting in a denser, fuzzier texture. The cloth or felt for implants are typically made from synthetic fibers such as PET (Polyethylene terephthalate) or Teflon (Polytetrafluoroethylene or PTFE).

[0060] Figures 6A-6D illustrate a peripheral edge 76 of the inner core 70 at the outermost extent of the conical outer wall 74. From the outer wall 74, the core 70 has a w?affle-like structure extending to an intermediate wall 78. The waffle structure is formed by a plurality of generally radially-oriented planner walls 80 spaced apart circumferentially in the space between the outer 74 and intermediate wall 78 to form open cells 82. The cells 82 are open to the outflow direction of the core 70, but closed on the inflow end.

[0061] With reference back to Figure 5, a number of concave ledges 84 are seen connecting the inner w-all 72 to the intermediate wall 78. The ledges 84 are generally radiallyoriented and extend between circumferentially spaced apart lands 86. The ledges 84 curve downward in the inflow direction from each land 86 and then upward to the next land. The concave ledges 84 are shaped to receive each of the arcuate cusps 28 of the leaflet subassembly 22, as seen in Figure 2. Indeed, although the inner core 70 is also fabric covered, the fabric conforms to the ledges 84 as shown. The leaflet subassembly 22 is thus position with the cusps 28 on the ledges 84 and attached to the sewing ring 24 using, for example, stitches (not shown).

[0062] Going back to the overall shape of the sewing ring 24, Figure 6D shows that the inner core 70 may be substantially planar w ith the height h indicated. As seen in Figure 6C, the inner wall 72 is circular, and is mirrored by the circular periphery 34 around a majority of the core periphery’, aside from the relatively flat side 36. The term “relatively flat” with regard to the side 36 means that its shape is relatively flatter than the remainder of the circular periphery 34. However, it will be apparent that the flat side 36 has a slight concavity, and thus is not strictly flat. For example, the majority circular periphery 34 may have a radius Ri centered about the center of core 70 w hich is smaller than radius R2of the flat side 36. In one exemplary embodiment, radius Ri is between about 30-50% of radius R2. Figure 60 also indicates a reference axis A which extends through the relatively flat side 36. The axis A is imaginary , though it may be indicated by a marker thread or the like, and is used by the surgeon to orient the sewing ring during implant at the tricuspid annulus as will be shown below.

[0063] Figures 9A and 9B are outflow and inflow perspective views of an annular inner core 90 of an alternative conformal sewing ring of the present application having waffle-like cells on both faces. As with the earlier embodiment, the inner core 90 is formed of a compressible, suture-permeable material, preferably silicone rubber, which is then covered with a biocompatible fabric (not show n). The inner core 90 has a frustoconical outer profile commencing at its widest point on the outflow face at a circular outer edge 92 circumscribing a circular radially inner wall 94. Also as with the previously-described embodiment, the core 90 defines intermediate w all segments 96 above each of a plurality^ of radially-oriented ledges 98. The inner wall 94 and intermediate wall segments 96 are generally axially- oriented and describe a circle to receive a leaflet assembly. The ledges 98 are sized and positioned to receive the arcuate inflow^ cusps of a leaflet subassembly, much as described above. The outflow face of the core 90 is defined between the outer edge 92 and an inner edge too, as seen in Figure 9A.

[0064] Figure 9C is a partial cutaway view’ of Figure 9A, and Figures 9D and 9E are sectional enlargements of the opposite side walls thereof. The waffle-like cells include those that open to the outflow face, and those that are located on the angled face of the frusto-conical outer profile. Namely, a plurality of radially-oriented ribs 102 distributed around the circumference of the core 90 extend between the outer edge 92 and inner edge too to define a plurality of cells 104 open to the outflow face. Angled webbing 105 extends outward from the inner wall 94 or intermediate wall 96 to the outer edge 92, and circumscribes the core 90 to provide a floor for the open cells 104. Similarly, a plurality of radially-oriented ribs 106 distributed around the frusto-conical outer profile of the core 90 extend betw een the outer edge 92 and an inflow corner 99 to define a plurality of cells 108 open toward the inflow face. The angled webbing 105 provides a divider for the two open cells 104, 108. The shapes of the various walls that define the cells 104, 108 are seen best in the cross-sections of Figures 9D and 9E. Chamfers 109 are provided at both inflow and outflow faces which help to improve assembly of the sewing ring with the leaflet subassembly as well as to reduce the bulk of the core 90 and improve compressibility.

[0065] The inner core 90 is entirely circular or annular, w ith no relatively straight sections as in the embodiment described above. Although circular sewing rings are imperfect fits in a regular native annuluses, the provision of open cells 102, 108 on both inflow and outflow faces of the core 90 increases compressibility and thus improves conformance w ith the irregular annulus. The sew ing ring having the inner core 90 can then be better stretched and compressed around its periphen as needed for a closer seal with the annulus, resulting in less blood leakage around the valve.

[0066] Figures 10A and 10B are outflow and inflow perspective views of an annular inner core 110 of a still further conformal sewing ring that is a combination of the cores 70 and 90 described above. That is, the overall peripheral shape of the core 110 is similar to the core 70, in that it has a somewhat D-shape with a majority circular portion 112 interrupted by one generally flat side 114 defined between corners 115. Plus, the core no has waffle-like cells on both faces, like core 90. Figure 10C is an outflow plan view, Figure 10D is another outflow^ perspective view, Figure 10E is a partial cutaway view- of Figure 10A, and Figures 10F and 10G are enlargements of sections through the opposite side walls thereof.

[0067] As with the circular core 90, the D-shaped core no has a frusto-conical outer profile with generally axially-oriented inner walls describing a circle so as to receive a leaflet assembly. An outer edge 116 forms the outermost extent of the core 110, and the inner walls are interrupted by three arcuate ledges 118 sized and shaped to receive the inflow cusps of a leaflet subassembly, such as shown in Figure 2.

[0068] The core no has waffle-like cells on both faces. In particular, cells 120 formed between radial ribs open to the outflow face, and cells 122 formed between radial ribs open in the frusto-conical outer profile toward the inflow face. Angled webbing 124 ending at the outer edge 116 provides a divider between the two cells 120, 122. Due to the open cells onboth faces, and the provision of a generally flat side 114, the core 110 when fabric-covered and assembled into a heart valve conforms better to the uneven and asymmetric tricuspid annulus than prior sew ing rings.

[0069] Figures 11A and 11B are outflow perspective views of somewhat ovoid core 130 for a conformal sewing ring having opposed outward lips on opposite longitudinal sides and waffle-like cells on both faces, and Figures 11C and 11D are inflow and outflow plan views thereof. As w ith the circular cores 90, 110, the ovoid core 110 has a frusto-conical outer profile with generally axially-oriented inner w alls 131 describing a circle to receive a leaflet assembly. An outer edge 132 forms the outermost extent of the core 130, and the inner walls are interrupted by three arcuate ledges 134 sized and shaped to receive the inflow cusps of a leaflet subassembly, such as show n in Figure 2. The core 130 has waffle-like cells on both faces. Angled webbing 136 separates cells 138 formed between radial ribs open to the outflow face from cells 138 formed between radial ribs open in the frusto-conical outer profile tow ard the inflow^ face.

[0070] As mentioned, the inner core 130 has a generally circular central opening defined by the inner walls 131, but a generally ovoid-shaped outer periphery. Figure 11C is a view of the outflow' face indicating four primary regions around the outer periphery. The periphery is convex except for along a generally flat side 144. Outwardly extending lips 145, 146 define a longitudinal axis X of the core 130, while a short convex side 147 and the opposite flat side 144 define a lateral axis Y. Since the inner walls are circular, the wider lips 145, 146 mean that the ribs and cells 138, 140 on both faces are larger around those regions. That is, the distance between the outer edge 132 and the inner walls 131 is greater in the lips 145, 146.

[0071] Looking at the inflow7view of Figure 11D, the relative widths of the lips 145, 46 are indicated. The larger lip 145 has a width W, while the smaller lip 146 has a smaller width w. The width between the inner walls 131 and outer edge 132 diminishes gradually between both of the lips 145, 146 and reaches minimums at the flat side 144 and short convex side 147. In a preferred embodiment, the smaller lip 146 has a width w that is between about 50-75% of the width W of the larger lip 145, while the width around the flat side 144 and short convex side 147 is about 25-40% of the width W of the larger lip 145.

[0072] The outer ovoid shape of the sewing ring having the inner core 130 is shaped to conform closely to the outline of the tricuspid annulus. Moreover, the open cells 138, 140 on both faces of the core 130 make the sewing ring highly compliant. Finally, the flat side 144 is provided to help avoid placing anchoring sutures through the components of the electrical system of the heart surrounding the tricuspid annulus, as w ill be seen below. The orifice for the flow through the valve body when assembled is slightly biased towards the antero-septal commissure.

[0073] Figure 12A is an outflow perspective view of an inner core 160 for another alternative conformal sewing ring having an upward rise on one side and w affle-like cells on both faces, and Figure 12B is a side elevational view illustrating the extent of the upw ard rise. As before, the sewing ring has an outer outermost edge 162 and an inner wall 164 which are both substantially circular in plan view’. Three arcuate ledges 166 interrupt the inner w all 164 so as to receive cusps of a leaflet subassembly, such as that shown in Figure 2.

[0074] The core 160 rises up at an axial bump 168 on one side. The angular extent of the bump 168 may be anywhere from 80-100°, and the bump rises up gradually from an otherwise flat outflow face. As seen in the figures, the bump has both a solid outer wall 170 and a solid inner w all 172. A series of cells 174 betw een ribs open to the outflow face, while a series of cells 178 between ribs open toward the inflow side on the outer frusto-conical profile of the core 160. Angled webbing 178 extending between the outer edge 162 and the inner wall 164 divide the cells 174, 176. The bump 168 extending out of the otherwise planar the sewing ring is intended to fit into an anatomical depression located near the anteroseptal commissure for better conformance to the tricuspid annulus.

[0075] Figure 13 is a schematic view’ of the tricuspid valve orifice seen from its inflow side (from the right atrium), with the peripheral landmarks labeled as: antero-septal commissure, anterior leaflet, antero-posterior commissure, posterior leaflet, postero-septal commissure, and septal leaflet. Contrary to traditional orientation nomenclature, the tricuspid valve is nearly vertical, as reflected by these sector markings.

[0076] From the same viewpoint, the tricuspid valve 220 is shown surgically exposed in Figure 14 with an annulus 222 and three leaflets 224a, 224b, 224c extending inward into the flow orifice. Chordae tendineae 226 connect the leaflets to papillary muscles located in the right ventricle to control the movement of the leaflets. The tricuspid annulus 222 is an ovoidshaped fibrous ring at the base of the leaflets that is less prominent than the mitral annulus, but larger in circumference. The annulus 222 is generally planar, but dips down toward the ventricle at a depression near the antero-septal commissure which often carries over along the septal leaflet 224a.

[0077] Reflecting their true anatomic location, the three leaflets in Figure 14 are identified as septal 224a, anterior 224b, and posterior (or “mural”) 224c. The leaflets join together over three prominent zones of apposition, and the peripheral intersections of these zones are usually described as commissures 228 (with anatomical references labeled in Figure 13). The leaflets 224 are tethered at the commissures 228 by the fan -shaped chordae tendineae 226 arising from prominent papillary muscles originating in the right ventricle. The septal leaflet 224a is the site of attachment to the fibrous trigone, the fibrous “skeletal” structure within the heart through which the heart’s electrical system passes. The anteriorleaflet 224b, the largest of the 3 leaflets, often has notches or clefts. The posterior leaflet 224c, the smallest of the 3 leaflets, usually is scalloped.

[0078] The ostium 230 of the right coronary sinus opens into the right atrium, and the tendon of Todaro 232 extends adjacent thereto. The conduction system formed by the AV node 234 and the beginning of the bundle of His 236 are located in the supero-septal region of the tricuspid valve circumference. The AV node 234 is situated directly on the right atrial side of the central fibrous body in the muscular portion of the AV septum, just superior and anterior to the ostium 230 of the coronary' sinus 230. Measuring approximately 1.0 mm x 3.0 mm x 6.0 mm, the node 234 is flat and generally oval shaped. The AV node 234 is located at the apex of the triangle of Koch 238, which is formed by the tricuspid annulus 222, the ostium 230 of the coronary sinus, and the tendon of Todaro 232. The AV node 234 continues on to the bundle of His 236, typically' via a course inferior to the antero-septal commissure 228 between the septal 224a and anterior 224b leaflets of the tricuspid valve; however, the precise course of the bundle of His 236 in the vicinity of the tricuspid valve may vary'.Moreover, the location of the bundle of His 236 may' not be readily apparent from a resected view of the right atrium because it lies beneath the annulus tissue.

[0079] The triangle of Koch 238 and tendon of Todaro 232 provide anatomic landmarks for locating the conduction system during tricuspid valve repair and replacement procedures. A major factor to consider during surgery is the proximity of the conduction system (AV node 234 and bundle of His 236) to the septal leaflet 224a. Of course, surgeons must avoid placing sutures too close to or within the AV node 234. C-shaped rings are good choices for tricuspid valve repairs because they allow surgeons to position the break in the ring adjacent to the AV node 234, thus avoiding the need for suturing at that location. However, valve replacements do not have such breaks, and thus the present application attempts to accommodate the sensitive conductive structures to avoid damage thereto.

[0080] Figure 15 is a plan view of the native tricuspid valve and surrounding anatomy from the inflow side with just the sewing ring 24 of the valve from Figure 1 sewn thereto in an implant position using stitches 250. Only the sewing ring 24 is shown so as to visualize more of the anatomical structures within the tricuspid annulus. It should be noted that the shape of the inner core 70 of the sewing ring 24 is the same as the shape of the inner core 110, and thus the sewing ring 24 may also have double-sided open cells.

[0081] The valve with the sewing ring 24 thereon is oriented so that the relatively straightened or flat side 36 of the D-shaped sewing ring lies along the tricuspid annulus at the septal leaflet, which is just inside of the main electrical components of the heart around the tricuspid annulus. That is, the reference axis A of the flat side 36 lies roughly parallel to the AV node 234, bundle of His 236 and triangle of Koch 238. In this w ay, potential forunwanted stress in the electrical system of the heart is reduced by reducing the amount of sewing ring extending into it.

[0082] Furthermore, the corners 38 flanking the flat side 36 provide additional space within the open cells of the waffle-like core of the sewing ring to facilitate placement or routing of pacing lead under or through the sewing ring. Typically, such pacing lead are placed near the postero-septal commissure, w hich is adjacent to one of the corners 38 flanking the flat side 36.

[0083] Figure 16 is another plan view of the native tricuspid valve and annulus with a heart valve having the sewing ring inner core 130 of Figures 11A-11D sewn thereto in an implant position. The valve is oriented so that the elongated axis X of the sewing ring inner core 130 aligns with the elongated axis of the tricuspid annulus. Furthermore, the flat side 144 lies roughly parallel to the electrical system surrounding the tricuspid annulus so that the sewing ring retracts radially inward at that region and reduce the potential for damage from anchoring sutures. The large lip 145 extends outward in the region of the antero-septal commissure, w'hile the shorter lip 146 extends outward in the region of the postero-septal commissure. Again, these enlarged structures help the sewing ring conform to the irregular tricuspid annulus, while also providing additional space for passage or routing of pacing leads.

[0084] Figure 17A is a schematic sectional view of the heart showing the atrioventricular valves between the atria and the ventricles. To recap, the mitral valve MV governs flow7between the left atrium LA and the left ventricle LV, while the tricuspid valve TV performs the same function between the right atrium RA and the right ventricle RV. The leaflets in both valves are shown open with blood flowing downward from each atrium to the respective ventricle. A reference plane R across the tricuspid valve TV generally represents a perpendicular to the blood flow direction. The openings of the mitral valve MV and tricuspid valve TV occur simultaneously during diastole, the cardiac cyclic phase where the heart muscles relax to expand the ventricles, allowing blood to flow into them. The systolic phase involves the opposite, with the heart muscles contracting to force blood from the ventricles through the aortic and pulmonic valves (not shown).

[0085] Figure 17B shows a step in advancing a surgical prosthetic heart valve 20 to the tricuspid annulus during implantation thereof. Surgical prosthetic heart valves are delivered with the heart stopped and blood pumped through the patient’s circulatory7system using an external cardiopulmonary bypass machine. Various access routes to the heart are known, including a full or partial sternotomy, providing access to the upper or superior portion of the heart. An incision in the wall of the right atrium RA is shown with retractors 260 utilized to widen and stabilize the incision. Replacement surgical valves may be implanted over thenative leaflets, or, as shown, the leaflets are excised leaving a short inward portion of the tricuspid annulus TA forming a shelf of sorts. Anchoring or implantation sutures 262 are then looped down and back up through the tricuspid annulus TA, and their free ends passed through the sewing ring 24 using suture needles while outside the body. A generally circular array of the looped sutures 262 is threaded in the appropriate locations around the sewing ring 24 so that the heart valve 20 may be lowered or parachuted onto the tricuspid annulus TA down the array of sutures. A typical number is 12-24 sutures.

[0086] Figure 17C shows the prosthetic heart valve 20 surgically implanted at the tricuspid annulus TA. The sewing ring 24 rests on the atrial side of the tricuspid annulus TA, and is secured thereto w ith knots 264 tied using each of the suture loops described above. Sometimes clips or other knotless fastener may be used instead. The tricuspid annulus TA is relatively tough, fibrous ring, and a variable number of sutures 262, such as 12-24, is adequate to secure the heart valve 20 in place against the pressures generated by the ventricle, w hich closes the valve leaflets 30. It should be noted that the heart valve 20 is oriented such that a centerline C / L therethrough generally aligns wdth the blood flow direction from the right atrium RA to the right ventricle RV. The centerline C / L is thus perpendicular to the reference plane R.

[0087] Figure 17D is a view of an outflow end of the heart valve 20 looking from the right ventricle. A such, the contours of the tricuspid annulus are a mirror image of that shown in Figure 13. As mentioned above, the electrical system of the heart mostly extends through the septal walls in between the right and left chambers, among other locations. Thus, the sewing rings described herein are desirably shaped to minimize disruption or piercings of the septal walls, or at least the respective annulus adjacent the septal walls. Likew ise, the septal wall SW such as seen in Figures 17C and 17D is spaced somew hat closer to the outflow portion of the heart valve 20 that extends into the right ventricle RV. Consequently, the prosthetic heart valve 20 is desirably rotationally oriented so that the commissure posts 26 are not located close to the septal wall SW; e.g., none is directly adjacent the septal wall SW.

[0088] Figure 17D illustrate a preferred orientation for a heart valve 20 having three commissure posts 26. Namely, none of the three commissure posts 26 that are rotationally spaced 120° from each other is directly adjacent to the septal wall SW. To ensure this orientation, the heart valve 20 desirably has at least two exterior markers 266 on the sewing ring 24 that each align wdth one of the commissure posts 26. The markers 266 enable the surgeon to rotationally orient the heart valve 20 so that none of the commissure posts 26 are in the problematic location; that is, none is directly adjacent the septal wall SW. For example, the surgeon may align the two markers 266 with the antero-septal commissure and the antero-posterior commissure as described below. The markers 266 may be coloredsutures sewn into the cloth of the sewing ring 24, or printed or laser applied markings. Desirably, the markers 26 are simple axially-oriented lines across the sewing ring 24 and centered at the locations of the commissure posts 26.

[0089] Figure 18 is an outflow^ plan view of the surgical prosthetic heart valve 20 having the conformal sewing ring 24 with the flat side 36, and Figure 19 is an outline of the heart valve superimposed upon a tricuspid valve looking from the ventricular side. It is apparent that the generally annular profile 34 of the sewing ring 24 does not exactly match the asymmetrical ovoid contours of the periphery of the tricuspid valve, and it should be understood that when parachuting surgical heart valves into place there is naturally some distortion of the sewing ring 24 and / or the annulus, which is natural and accommodated by the relatively flexible nature of both. The conformal sewing ring 24 may be formed with a cloth-covered inner core such as those show n at core 70 and core 110 above, with molded w alls dividing a volume of the inner core into cells. Or, the sewing ring 24 may be rolled or folded cloth without an inner core.

[0090] Both Figures 18 and 19 orient the commissure posts 26 in the approximately preferred location, such that no commissure post is directly adjacent the septal wall SW from which the septal leaflet extends. Instead, one commissure post 26a is located at approximately the antero-septal commissure, while another 26b is generally coincident with the antero-posterior commissure, and the third 26c is at the posterior end of the septal leaflet. Moreover, no commissure post 26 is directly adjacent the most sensitive portions of the conduction system - the Bundle of His 236 and the AV Node 234. The commissure posts 26 are the tallest part of the valve extending into the ventricle, and one would not want to risk impinging upon the Bundle of His by placing a post directly adjacent to it. Likewise, the orientation avoids positioning a post 26 adjacent the AV node 234 (see Figure 14).

[0091] Orienting the sewing ring 24 in this fashion places the flat side 36 substantially along the septal leaflet, which is somewhat flatter than the remaining ovoid tricuspid annulus. As will be seen below, fewer or no anchoring sutures may be used in this area to further avoid potential damage to the conduction system in the septal wall SW.

[0092] Figure 20A is a perspective view of another surgical prosthetic heart valve 280 having the conformal sewing ring show ing the inner core 160 from Figure 12A without a fabric covering. Normally there would be a fabric covering around the inner core 160, but such is omitted for clarity. The heart valve 280 is shown with the aforementioned leaflet subassembly 22 seated within the sewing ring 160. To reiterate, the subassembly 22 comprises a peripheral stent having three upstanding commissure posts 26 alternating with three arcuate cusps 28 supporting three flexible leaflets 30 having a coapting free edges 32.Figure 20B is an isolated perspective view of the inner core 160 w ith a number of features identified by number. As before, the inner core 160 has open cells on both faces.

[0093] The axial bump 168 on one side of the inner core 160 may be located around the valve 280 in several places depending on anatomical considerations. For example, Figure 21 is an outline of the heart valve of Figure 20A superimposed upon a tricuspid valve looking from the ventricular side. The bracket 282 indicates one potential placements for the axial bump 168. In this location, the axial bump 168 commences at a first commissure post 26a, and extends to a second commissure posts 26c, spanning across a cusp region of the heart valve. Although the view in Figure 21 is looking from the ventricular side, the axial bump 168 begins just anterior of the antero-septal commissure and extends roughly halfway across the septal leaflet. Studies have shown that many patients have an anatomical depression toward the ventricular side near the antero-septal commissure, and the axial bump 168 is intended to conform to that depression. There is of course patient-to-patient variability in the exact contours of the tricuspid annulus, but an assumption that the depression is located in this at the bracket 282 is an attempt to capture the majority7of patients’ anatomies. A second axial bump or depression for that matter may be included to conform to other anatomical features as needed, and the present application contemplates more than one of each.

[0094] Figure 22A is a schematic sectional view of the right side of the heart showing one common shape of the tricuspid annulus. The reference plane R that was previously described remains in the same location, which illustrates how the septal aspect SA of the tricuspid annulus often dips down toward the right ventricle RV. Figure 22B shows the prosthetic heart valve 280 of Figure 20A surgically implanted with the axial bump 168 shown conforming to the depressed septal aspect SA. The conforming sewing ring 160 thus maintains the centerline C / L of the heart valve 280 perpendicular to the original reference plane R, which thus aligns the blood flow through the valve with the natural blood flow.

[0095] When determining the particular shape of the conformal sewing ring, the dynamic contours of the tricuspid annulus are important to consider, in particular the position of the tricuspid annulus relative to adjacent valves. For example, the anterior side of the aortic annulus has a motion lifting away from the aorta during systolic ejection that creates a saddle shape. This upward lift takes the mitral annulus out of the LVOT during systolic ejection. During diastole, the aortic annulus flattens out and takes a rounder shape to maximize the flow area as blood is flowing from the atria to the ventricle. The tricuspid ring has a similar dynamic motion, though the tricuspid annulus folds down away from the aorta in the antero-septal commissure region during systolic ejection to avoid pressing into the aorta and restricting flow. This is why the antero-septal commissure area drops down when the valve is closed but raises up during diastole when the valve is open, per observationand modeling. Providing a bulky sewing ring around a prosthetic tricuspid valve in the antero-septal area may impede this motion of the aorta. (See Figure 13 for the location of the aorta.)

[0096] Figure 23A is a perspective view of an inner core 290 of another conformal sewing ring having a portion removed, and Figure 23B is a side elevational Anew of the inner core. The inner core 290 is shown nearly identical to the inner core 160 from Figure 12A, but incorporates a cut out 292 on one side thereof opening to an outflow edge of the core. The cut out 292 extends partly into the axial bump 168, and continues across a commissure region into an adjacent cusp region.

[0097] Figure 24 is an outline of a heart valve 294 having a sewing ring with the inner core 290 of Figure 23A superimposed upon a tricuspid valve looking from the ventricular side. The bracketed region 296 indicates where the cut out 292 will be located. That is, the cut out 292 in the sewing ring is desirably positioned in the antero-septal commissure area so as to reduce pressure from the tricuspid sewing ring on the aorta. Reference again is made to Figure 13 as to an approximate location of the aorta looking from the atrial side of the tricuspid valve. By reducing material in the inner core 290 in the antero-septal commissure region, any impact on movement of the aorta from the bulk of the sewing ring and any attachments sutures is minimized.TRICUSPID VALVES WITH DISCONTINUOUS ANCHORING

[0098] Figures 25A and 25B are perspective and inflow plan views of a still further surgical prosthetic heart valve 300 that show a conformal sewing ring 302 having a plush fabric portion 304 thereon. The heart valve 300 is in most respects similar to the heart valve 20 seen in Figure 1, and as such like elements will be given like numbers. The difference is the plush fabric portion 304. As before, the sewing ring 302 has a substantially annular periphery with the flat side 36 between two corners 38. The plush fabric 304 is provided between the two corners 38 in the flat side 34. Figure 25B indicates a reference axis A which extends through the relatively flat side 36, and described above with respect to Figure 6C. The axis A may be indicated by a marker thread or the like on the inflow side of the sewing ring 302, and may be used by the surgeon to orient the sewing ring during implant at the tricuspid annulus.

[0099] Highly texturized cloth elicits a more vigorous fibrous tissue response, and thus it is beneficial to only provide the plush fabric 304 in the septal region. This cloth should also be highly compressible so sutures placed at both ends of the septal region, into the fibrous portion of the annulus, will bring the cloth into contact with the annulus across the entire width of the septum. The present application thus contemplates the plush fabric 304 around the entire heart valve 300, or just in the flat side 36 region as seen in Figures 25A and 25B.To reiterate, the sewing ring 302 may be formed w ith a cloth-covered inner core such as those shown at core 70 and core 110 above, with molded walls dividing a volume of the inner core into cells, or the sewing ring 302 may be rolled or folded cloth without an inner core.

[0100] The plush fabric 304 is distinct from the otherwise smooth and relatively incompressible biocompatible fabric on the remainder of the sewing ring 302. The plush fabric 304 is intended to encourage some tissue ingrowth and fill any gap along the septal portion of the annulus to prevent leakage around the valve as an alternative to attachments sutures or the like across the entire septal portion of the annulus w here the critical conduction system features lie. As is known, surgical prosthetic heart valves may be attached to the target valve annulus using sutures, clips, staples, or similar expedients, and the term attachment member or members will be used to refer to any of these expedients. The plush fabric 304 is provided to eliminate the need to place sutures or other attachment members across the entire length of the septal region of the heart limiting the need for sutures to the fibrous portion of the annulus adjacent to the septal / anterior and septal / posterior commissures.

[0101] The differential pressure across a closed tricuspid valve is much lower than the pressure across an aortic or mitral valve because the RV pressure is in the 20-30 mmHg range, while the left ventricular pressure is in the about 90-140 mmHg range and can exceed about 200 mmHg. Consequently, there is less pressure driving paravalvular blood leakage between the sewing ring and the native annulus. As such, the present application contemplates surgically placing a tricuspid valve with sutures or other attachment members without placing any near the AV node or bundle of His (e.g., an area located between the antero-septal commissure and the postero-septal commissure) to avoid the risk of damaging the conduction system. One possible technique is to avoid placing sutures or attachment members within 2 mm of the Bundle of His or the AV Node.

[0102] The modification to enable this implant procedure involves the use of the plush compressible highly texturized cloth 304 in the septal region, such as double velour cloth. Cloth configurations that seal around other heart valves such as transcatheter heart valves that don’t have sutures holding the valve to the annulus are disclosed in WO 2018 / 222799, US 11,389,310, US 2008 / 039521, US 2024 / 0081988, US 2024 / 0008978 and, US 12,064,348, all expressly incorporated herein by reference. However, transcatheter heart valves comprise expandable frames which provide outward pressure on the annulus. Surgical valves, on the other hand, are static in shape (e.g., non-compressible, non-expandable) and require some attachment structure. The region in w'hich the plush fabric 304 is provided thus has attachment members only at the ends of the plush cloth to assure attachment of the valve into the fibrous structure of the annulus, but also there is no approximating structure nearthe conduction system such as an expandable stent or clamping mechanism, as in some prior art sutureless anchoring solutions. The plush fabric 304 just lies in contact w ith the annulus, with nothing else to hold it in place.

[0103] The method involves no sutures, hooks or clamping structures to approximate the septal portion of the sewing ring to the annulus. The width of the plush fabric 304 should be limited to an area along the septal side of the annulus, with no approximating structures over a distance of at least 6 mm. Of course, the width of the plush fabric 304 could extend the entire distance across the flat side 36, w-hich is approximately the distance between the corners 38, or between two of the commissures 26 of the valve 300. The plush fabric 304 could extend over the inflow- face of the sewing ring, for ease of manufacturing, though it is generally only functional on the outflow- face of the sewing ring extending to the periphery of the sewing ring. That is Figures 25A and 25B show the plush fabric 304 just on the outer periphery of the sewing ring 302, without extending radially inw ard very’ far. In a preferred embodiment, the plush fabric 304 is only provided in areas of contact betw een the annulus and the sewing ring.

[0104] Figures 26A-26C illustrate a sequence of delivery of the heart valve of Figure 25A to a tricuspid annulus, and Figure 26D shows the implanted heart valve from the ventricular side. The tricuspid valve 220 is shown as in Figure 14, with an annulus 222 and three leaflets extending inward into the flow orifice. The components of the conduction system adjacent the septal leaflet are once again shown to indicate the sensitive areas.

[0105] In a conventional implant procedure, an array of sutures 310 are pre-installed around the annulus 222. Two terminal sutures 312 are placed at the very ends of the fibrous septal aspect past the native commissures on either side of the septal leaflet, though still outside of the area of the conduction system. Figure 26B shows the heart valve 300 after having been parachuted down the array of sutures 310, 311 (only a subset for shown for clarity) until the sewing ring 302 contacts the tricuspid annulus 222. Subsequently, Figure 26C shows knots 314, 316 having been tied between each of the free ends of the suture loops 310 to secure the sewing ring 302 onto the annulus. Two knots 316 are located at the corners of the flat side 36 corresponding to the terminal sutures 312. It should be noted that there are no knots 314 in the middle of the flat side 36 of the sewing ring 302, adjacent to the conduction system and the septal leaflet of the tricuspid annulus. Sutures are placed on either end of the flat portion of the sewing ring to assure attachment of the valve through the fibrous region of the annulus and to compress the plush fabric against the septal annulus.

[0106] In Figure 26D, the outflow side of the prosthetic heart valve 300 is seen extending downward into the ventricle. The portions of the suture loops 310 that pass through the tricuspid annulus are also seen. The region 314 indicates the sensitive area adjacent theconduction system in which no attachments sutures are installed. Instead, the plush fabric 304 on the outer edge of the sewing ring 302 provides initial and long-term paravalvular sealing around the sew ing ring 302. It is believed that eliminating attachment members and any approximating structure along the septal leaflet in this manner greatly reduces the chances of damaging the cardiac conduction system.

[0107] While the foregoing is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. Moreover, it will be obvious that certain other modifications may be practiced within the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A prosthetic heart valve having a conformal sewing ring adapted for implant at a native tricuspid annulus, the tricuspid annulus defining an asymmetric ovoid shape as seen looking at an inflow side of the tricuspid valve circumscribing the following anatomical landmarks of the native tricuspid valve as seen in series in a clockwise direction: an anteroseptal commissure, an anterior leaflet on an anterior side, an antero-posterior commissure, a posterior leaflet on a posterior side, a postero-septal commissure, and a septal leaflet on a septal side, the native tricuspid valve further having a long dimension extending approximately from the antero-septal commissure to the postero-septal commissure with the septal leaflet extending therebetween, and wherein the septal leaflet is located inward of electrical structure of the heart including an atrioventricular node (AV node) and a bundle of His extending clockwise the AV node, the AV node being in turn located clockwise adjacent an apex of a triangle of Koch that is formed by the septal side, an ostium of the coronary sinus, and the tendon of Todaro, the heart valve comprising: a cloth-covered valve stent defining an orifice about a central axis, the valve stent having an inflow end and outflow commissure posts extending in an outflow direction away from the inflow end, and wherein inflow is down and outflow is up; a plurality of flexible leaflets are attached to the valve stent and extend within the valve stent orifice to enable one-way flow regulation of blood through the orifice; and a suture-permeable sewing ring attached around the inflow end of the valve stent, the sewing ring defining a circular inner wall and a substantially D-shaped outer periphery with one flat side being flatter than a remaining convex periphery.

2. The heart valve of claim 1, wherein the sewing ring is formed by an elastomeric inner core covered in cloth, and the inner core is molded to have w alls dividing a volume of the inner core into cells open at least toward an outflow face of the inner core.

3. The heart valve of claim 2, w herein the inner core w alls form cells open tow ard both an inflow face and the outflow face of the inner core.

4. The heart valve of claim 2, wherein the cloth covering the inner core is mostly a smooth and relatively incompressible biocompatible fabric except for on the flat side on which is provided a highly compressible plush fabric.

5. The heart valve of claim 4, wherein the plush fabric is provided just on an outer periphery' of the sewing ring, without extending radially inward to the valve stent.

6. The heart valve of claim 4, wherein the plush fabric is provided just within a middle portion of the flat side with outer corners of the flat side having the smooth and relatively incompressible biocompatible fabric.

7. The heart valve of claim 1, wherein the sewing ring is formed by a rolled or folded cloth or felt w hich is smooth and relatively incompressible except for on the flat side w-hich is a highly compressible plush fabric.

8. The heart valve of claim 7, wherein the plush fabric is provided just on an outer periphery of the sewing ring, without extending radially inward to the valve stent.

9. The heart valve of claim 7, wherein the plush fabric is provided just within a middle portion of the flat side with outer corners of the flat side having the rolled or folded cloth or felt.

10. The heart valve of claim 1, wherein the sewing ring defines a flat annular shape with no up or dow n portions.

11. A prosthetic heart valve having a conformal sewing ring adapted for implant at a native tricuspid annulus, the tricuspid annulus defining an asymmetric ovoid shape as seen looking at an inflow side of the tricuspid valve circumscribing the following anatomical landmarks of the native tricuspid valve as seen in series in a clockwise direction: an anteroseptal commissure, an anterior leaflet on an anterior side, an antero-posterior commissure, a posterior leaflet on a posterior side, a postero-septal commissure, and a septal leaflet on a septal side, the native tricuspid valve further having a long dimension extending approximately from the antero-septal commissure to the postero-septal commissure with the septal leaflet extending therebetween, and wherein the septal leaflet is located inward of electrical structure of the heart including an atrioventricular node (AV node) and a bundle of His extending clockwise the AV node, the AV node being in turn located clockwise adjacent an apex of a triangle of Koch that is formed by the septal side, an ostium of the coronary sinus, and the tendon of Todaro, the heart valve comprising: a cloth-covered valve stent defining an orifice about a central axis, the valve stent having an inflow end and outflow commissure posts extending in an outflow direction away from the inflow’ end, and w herei n inflow^ is down and outflow is up; a plurality of flexible leaflets are attached to the valve stent and extend within the valve stent orifice to enable one-way flow regulation of blood through the orifice; and a suture-permeable sewing ring attached around the inflow’ end of the valve stent, the sewing ring defining a circular inner w all and a generally ovoid outerperiphery with a long axis and a short axis that forms elongated lips projecting from the inner wall outward along the long axis that are longer than portions extending from the inner wall outward along the short axis.

12. The heart valve of claim n, wherein the sewing ring is formed by an elastomeric inner core covered in cloth, and the inner core is molded to have walls dividing a volume of the inner core into cells open tow ard both an inflow face and an outflow- face of the inner core.

13. The heart valve of claim 12, wherein the inner core has a frusto-conical outer profile with generally axially-oriented inner w alls describing a circle to receive the cloth- covered valve stent.

14. The heart valve of claim 13, w herein an outer edge forms an outermost extent of the inner core, and the inner walls are interrupted by three arcuate ledges sized and shaped to receive inflow cusps of the cloth -covered valve stent.

15. The heart valve of claim 12, wherein the inner core has angled webbing separating the cells and formed between radial ribs open to the outflow face from the cells formed between radial ribs open tow ard the inflow^ face.

16. The heart valve of claim 11, wherein the elongated lips include a larger lip having a radial width W and a smaller lip having a smaller width w that is between about 50-75% of the width W.

17. The heart valve of claim 11, w-herein the outer periphery is convex except for along one flat side intersecting the short axis.

18. A prosthetic heart valve having a conformal sewing ring adapted for implant at a native tricuspid annulus, the tricuspid annulus defining an asymmetric ovoid shape as seen looking at an inflow side of the tricuspid valve circumscribing the following anatomical landmarks of the native tricuspid valve as seen in series in a clockwise direction: an anteroseptal commissure, an anterior leaflet on an anterior side, an antero-posterior commissure, a posterior leaflet on a posterior side, a postero-septal commissure, and a septal leaflet on a septal side, the native tricuspid valve further having a long dimension extending approximately from the antero-septal commissure to the postero-septal commissure with the septal leaflet extending therebetween, and w-herein the septal leaflet is located inward of electrical structure of the heart including an atrioventricular node (AV node) and a bundle of His extending clockwise the AV node, the AV node being in turn located clockwise adjacent an apex of a triangle of Koch that is formed by the septal side, an ostium of the coronary sinus, and the tendon of Todaro, the heart valve comprising:a cloth-covered valve stent defining an orifice about a central axis, the valve stent having an inflow end and outflow commissure posts extending in an outflow direction away from the inflow end, and wherein inflow is down and outflow is up; a plurality of flexible leaflets are attached to the valve stent and extend within the valve stent orifice to enable one-way flow regulation of blood through the orifice; and a suture-permeable sewing ring attached around the inflow end of the valve stent, the sewing ring defining a flat annular shape around a majority of a periphery thereof with an axial bulge extending in the outflow direction on one side thereof, and the inner core is molded to have walls dividing a volume of the inner core into cells open toward both an inflow face and an outflow face of the inner core.

19. The heart valve of claim 18, wherein the angular extent of the axial bulge is between 80-100°.

20. The heart valve of claim 18, wherein the axial bulge rises up gradually from an otherwise flat outflow face.

21. The heart valve of claim 18, wherein the axial bulge has both a solid outer wall and a solid inner wall.

22. The heart valve of claim 18, wherein the inner core has angled webbing separating the cells and formed between radial ribs open to the outflow face from the cells formed between radial ribs open toward the inflow face.

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