1 GASKET WITH SPRING COLLAR FOR PROSTHETIC HEART VALVES AND METHODS FOR MAKING AND USING THEM
This application claims benefit of provisional application Ser. No. 60/743,185, filed Jan. 27, 2006, the entire disclosure of which is expressly incorporated herein by reference.
The present invention relates generally to heart valves that may be implanted within a patient, and, more particularly, to multiple component heart valve assemblies, and to apparatus and methods for making and using them.
Prosthetic heart valves can replace defective human valves in patients. For example, one piece valves have been suggested that include sewing rings or suture cuffs that are attached to and extend around the outer circumference of a prosthetic valve. In addition, multiple component valves have also been suggested that include a sewing ring that is separate from a valve component. The sewing rings of either type of prosthetic valve can be tedious and time consuming to secure within a target site, i.e., within an annulus of a heart where a natural heart valve has been removed.
For example, to implant a sewing ring within an annulus of a heart, between twelve and twenty sutures may be secured initially to tissue surrounding the annulus. The sewing ring and/ or the entire prosthetic valve may then be advanced or “parachuted” down the sutures into the amiulus. Knots may then be tied with the sutures to secure the sewing ring within the annulus, whereupon the sutures may be cut. Consequently, this procedure can be very complicated, requiring management and manipulation of many sutures. The complexity of the procedure also provides a greater opportunity for mistakes and requires a patient to be on cardiopulmonary bypass for a lengthy period of time.
Because the annulus of the heart may not match the circular cross-section of the sewing ring and/or prosthetic valve, the prosthetic valve may not fit optimally within the annulus. As a result, natural blood hemodynamics through and around the valve may be impaired, resulting in clotting, possible emboli production, and eventual calcification of the valve structure.
To address this concem, flexible sewing rings have been suggested for use with multiple component valves. The sewing ring may be implanted within the annulus, e.g., using the procedure described above, i.e., parachuted down an arrangement of sutures. The sewing ring may conform at least partially to the anatomy of the annulus. Altematively, instead of using sutures, it has also been suggested to drive staples through the sewing ring into the surrounding tissue to secure the sewing ring.
When a mechanical or other prosthetic valve is then attached to the sewing ring, however, the valve and sewing ring may not mate together effectively, e. g., if the shape of the sewing ring has been distorted to confonn to the amiulus, which may also impair natural blood hemodynamics, create leaks, and/or otherwise impair performance of the prosthetic valve.
The present invention is directed to heart valves that may be implanted within a patient, and, more particularly, to mul
tiple component heart valve assemblies, and to apparatus and methods for making and using them.
In accordance with one embodiment, a prosthesis is provided for receiving a prosthetic valve to replace a preexisting natural or prosthetic heart valve within a biological annulus adjacent a sinus cavity. The prosthesis may include an annular member implantable within the biological amiulus, a collar extending upwardly from the annular member, and a sewing ring extending radially outwardly from at least one of the annular member and the collar. The collar and/or annular member may be resiliently compressible, expandable, and/or otherwise movable relative to one another. For example, the collar may be biased to a predetermined orientation, e.g., substantially aligned with a longitudinal axis of the annular member, yet may be compressible axially towards the annular member and/ or movable transversely relative to the longitudinal axis.
In accordance with another embodiment, a prosthesis is provided for receiving a prosthetic valve to replace a preexisting natural or prosthetic heart valve within a biological annulus adjacent a sinus cavity. The prosthesis may include an annular member implantable within the biological annulus for contacting tissue surrounding the biological annulus, a collar for engaging with a prosthetic valve, and a spring structure for supporting the collar away from the annular member, e.g., along a longitudinal axis. For example, the spring structure may allow the collar to be compressed towards the annular member along the longitudinal axis and/ or transversely relative to the longitudinal axis, yet be resiliently biased to a predeterminedposition away from the annular member. Optionally, the prosthesis may include a sewing ring, e.g., extending radially outwardly from at least one of the collar and the annular member. The spring structure may also allow the collar to be deflected, folded, and/or compressed transversely relative to the longitudinal axis, e.g., to facilitate accessing the sewing ring and/or annular member during implantation.
In accordance with still another embodiment, a heart valve assembly is provided for implantation within a biological annulus. The heart valve assembly may include an annular prosthesis that includes an annular member implantable within a biological amiulus, a collar extending upwardly from the annular member, and a spring structure for supporting the collar away from the annular member, e.g., along a longitudinal axis of the annular member. The heart valve assembly also includes a prosthetic valve, e.g., a mechanical orbioprosthetic heart valve, which may have a circular or multiple lobular shape for implantation above the biological annulus.
Optionally, one or more connectors may be provided on at least one of the collar and the prosthetic valve for securing the prosthetic valve to the annular prosthesis. For example, the one or more connectors may include a plurality of tabs or detents, a drawstring, and the like on the collar for engaging a frame of the prosthetic valve. Altematively, the one or more connectors may include one or more latches, detents, interlocking elements, e.g., on the prosthetic valve and/or the annular prosthesis.
In one embodiment, the collar may include a plurality of tabs that capture a portion of a frame of the prosthetic valve when the prosthetic valve is directed into engagement with the collar. Optionally, the tabs may be movable, e.g., using a tool, to release the prosthetic valve from the collar.
In exemplary embodiments, the collar, annular member, spring structure, and/or sewing ring may be formed from resiliently flexible material, e.g., metal, such as Nitinol, Elgiloy, or stainless steel, an elastomer, such as silicone, or other plastic material, and may be covered at least partially
with a fabric covering. The collar, annular member, and/or spring structure may be fonned as a unitary piece or may be separate components that are attached to one another, e.g., before or after being covered with fabric.
In accordance with yet another embodiment, a method is provided for implanting a prosthetic heart valve assembly within a biological annulus, e.g., adjacent a sinus cavity. An annular member may be introduced into the biological annulus, e.g., to direct tissue surrounding the biological annulus outwardly and/or to at least partially dilate the biological annulus. A flexible sewing ring may extend around the annular member that may receive one or more comiectors, e.g., sutures, clips, and the like, to secure the 211111111211‘ member relative to the annulus.
In one embodiment, a collar or stand-off extends upwardly from the 211111111211‘ member for receiving the prosthetic valve. The collar may be coupled to the annular member by a spring structure, which may bias the collar to a predetermined position relative to the annular member, but allow the collar to be moved relative to the annular member. For example, the collar may be folded or otherwise moved transversely to facilitate access to the sewing ring, e.g., for directing one or more connectors through the sewing ring. In addition, the collar may be compressible towards the annular member, but resiliently biased to direct the collar upwardly, e.g., within the sinus cavity above the biological annulus.
A prosthetic valve, e.g., a mechanical or bioprosthetic valve, may be advanced into the sinus cavity, and secured relative to the annular member. For example, the prosthetic valve may be secured to the collar using one or more com1ectors, e.g., a plurality of tabs or detents on the collar, a drawstring in the collar, one or more sutures, clips, detents, and/or other cooperating connectors, e.g., on the collar and/ or frame of the valve prosthesis.
The collar may support the prosthetic valve above the tissue biological, e.g., within the sinus cavity, e.g., the sinus of Valsalva above an aortic valve site. In addition or alternatively, the collar may allow the prosthetic valve to have a larger size than the annular member, thereby enhancing the fluid flow or other perfonnance characteristics of the implanted heart valve assembly. Optionally, the collar may include a furmel or other tapered shape that may provide a transition from a relatively larger prosthetic valve to the annular member within the biological annulus. In addition, the collar may support the prosthetic valve away from a wall of the sinus or other supra-annular space, while still allowing blood to flow easily into the coronary arteries around the prosthetic valve.
In another option, the prosthetic valve may be removable from the collar, e.g., to allow the prosthetic valve to be replaced. In addition or alternatively, the collar and prosthetic valve may have a substantially circular shape, which may allow the prosthetic valve to be secured to the collar, yet be rotatable relative to the collar.
Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate exemplary embodiments of the invention, in which:
FIG. 1 is a partial cross-sectional side view of an exemplary embodiment of a gasket member with a fabric covering.
FIG. 2 is a side view of a collar including a spring structure and an 211111111211‘ ring that may be provided in the gasket member of FIG. 1.
FIG. 3A is a cross-sectional side view of an unfinished blank that may be fonned into the collar and spring structure of FIG. 2.
FIG. 3B is a cross-sectional side view of a collar and spring structure formed from the blank of FIG. 3A.
FIG. 4 is a perspective view of a two piece heart valve assembly including a gasket member of FIG. 1 and a mechanical valve.
FIG. 5 is a cross-sectional view of an aortic valve site, having the heart valve assembly of FIG. 4 implanted therein.
Turning to the drawings, FIGS. 1-5 show an exemplary embodiment of a heart valve assembly 10 that generally includes a gasket member 12 and a valve member 14. Generally, the gasket member 12 includes an annular ring 18, a sewing ring 20 extending radially from the annular ring 18, and a collar 22 extending upwardly from the annular ring 18. The valve member 14 may be a prosthetic valve, e.g., a mechanical or bioprosthetic valve, that may be secured to the collar 22 and/or other portion of the gasket member 12, e.g., after implanting the gasket member 12 within a tissue annulus, as described further elsewhere herein.
Turning to FIGS. 4 and 5, the valve member 14 may be a mechanical valve including an annular frame 32 supporting a pair of valve members 38 (shown in FIG. 5) that open and close within the frame 32. Optionally, the valve member 14 may include a pair of ears 34 extending downwardly from the frame 32, e.g., for pivotally supporting the valve members 38. In an exemplary embodiment, the valve member 14 may be a mechanical valve, such as the “Regent” Bileaflet Valve manufactured by St. Jude Medical. In altemative embodiments, the valve member 14 may be another mechanical or bioprosthetic valve, such as those disclosed in U.S. Pat. No. 6,371,983 or U.S. Publication Nos. 2005/0043760, 2006/0235508, or 2006/0276888, the entire disclosures of which are expressly incorporated by reference herein.
Returning to FIGS. 1 and 2, an exemplary embodiment of the gasket member 12 is shown that includes an annular ring 18, a sewing ring 20, a collar 22, and a spring structure 40 supporting the collar 22 relative to the 211111111211‘ ring 18. Fabric 24 may cover all or at least a portion of the gasket member 12, e.g., the annular ring 18, the sewing ring 20, the collar 22, and/or the spring structure 40, for example, to allow tissue ingrowth and/or provide desired flexibility, similar to embodiments described in US Publication Nos. 2004/ 0122516, 2005/0165479, 2006/0195184, and 2007/0016285, the entire disclosures of which are expressly incorporated by reference herein.
In one embodiment, the annular ring 18 may have a generally circular shape, e.g., defining a central longitudinal axis 19. Alternatively, the annular ring 18 may have a multi-lobular shape about its circumference, e.g., including three lobes separated by scallops or cusps (not shown). In addition or altematively, the annular ring 18 may generally define a plane substantially perpendicular to the axis 19 or may have a sinusoidal or other shape that extends above and below a plane.
Optionally, the annular ring 18 may be expandable and/or contractible such that the diameter may be adjusted. In one embodiment, the annular ring 18 may be biased to expand to a predetennined diameter. If desired, the annular ring 18 may be contracted radially to a smaller diameter, e.g., folded or
|
