The present invention relates to replacement valves for the circulatory system. It finds particular application in conjunction with mitral valves for human hearts and will be described with particular reference thereto.
Heretofore, various styles of flow operated check valves have been utilized as replacement heart valves. One prior art heart valve includes a ball and valve seat arrangement which limits blood flow to a single direction. A cage surrounding the ball and attached to a sewing ring around the valve seat limits movement of the ball away from the valve seat and natural blood flow.
In another prior design, a tilting or pivotal disk is mounted in the valve seat. Flow in one direction causes the disk to tilt perpendicular to the seat, allowing blood flow. Pressure in the other direction presses the disk valve closed.
In another mechanical valve, a pair of flexible leaflets close the opening between the sewing ring. The leaflets are configured to flex in one direction with flow, permitting blood flow in that direction. Pressure in the opposite direction presses the leaflets together into a sealing relationship.
Bioprosthetic valves have also been utilized. For example, an aortic valve from a pig has been mounted in the sewing ring and used as a replacement mitral valve. However, this aortic valve has three leaflets; whereas, the human mitral valve has two. Further, the cross-section of the leaflets in the bioprosthetic valve is different from those in humans.
All of these valves work based on pressure differential. However, the human mitral valve operates with muscular assistance. Marginal and basal chordae extend from a lower surface of each leaflet to the papillary muscles. This muscle assists in valve operation. After a valve replacement with any of the above-discussed replacement valves, the papillary muscle no longer provides this assistance function.
The present invention overcomes the above-referenced problems and others.