Prosthetic heart valves
A prosthetic heart valve (e.g., a prosthetic aortic valve) is designed to be somewhat circumferentially collapsible and then re-expandable. The collapsed condition may be used for less invasive delivery of the valve into a patient. When the valve reaches the implant site in the patient, it re-expands to normal operating size, and also to engage surrounding tissue of the patient. The valve includes a stent portion and a ring portion that is substantially concentric with the stent portion but downstream from the stent portion in the direction of blood flow through the implanted valve. When the valve is implanted, the stent portion engages the patient's tissue at or near the native valve annulus, while the ring portion engages tissue downstream from the native valve site (e.g., the aorta).
1. A prosthetic heart valve having a proximal end and a distal end comprising:
an annular ring portion at an outflow end of the prosthetic heart valve;
a stent portion adjacent the ring portion, the stent portion having a first annular blood-outflow-edge region upstream of a second annular blood-outflow-edge region, the first annular blood-outflow-edge region being congruent with the second annular blood-outflow-edge region; and
a plurality of valve leaflets supported by the stent portion,
wherein the first annular blood-outflow-edge region and the second annular blood-outflow-edge region extend annularly around the valve in a serpentine pattern having peaks and troughs;
wherein the first annular blood-outflow-edge region and the second annular blood-outflow-edge region are spaced apart by elongated slots, the slots being interrupted by links connecting the first annular blood-outflow-edge region and the second annular blood-outflow edge region, wherein the peaks of the first annular blood-outflow-edge region are not directly coupled to corresponding peaks of the second annular blood-outflow-edge region, so the peaks of the first and second annular blood-outflow-edge regions are capable of independent movement relative to one another in the vicinity of strut structures that connect the ring portion to the stent portion,
wherein each of the plurality of valve leaflets includes an upper free edge and a lower edge, the lower edge passing through a corresponding one of the elongated slots.
2. The prosthetic heart valve of claim 1 , wherein the first annular blood-outflow-edge region and the second annular blood-outflow-edge region undulate alternately upstream and downstream relative to the direction of blood flow annularly around the valve.
3. The prosthetic heart valve of claim 1 , wherein the ring portion is integrally connected to the stent portion via struts.
4. The prosthetic heart valve of claim 3 , wherein the ring portion and the stent portion are connected by struts that form dual open bars.
5. The prosthetic heart valve of claim 1 , wherein the ring portion is spaced from the stent portion such that the plurality of valve leaflets cannot contact the ring portion.
6. The prosthetic heart valve of claim 1 , wherein the ring portion and the stent portion are annularly compressible to substantially the same circumference.
7. The prosthetic heart valve of claim 6 , wherein the ring portion is re-expandable to a circumferential size that is greater than the circumferential size of at least a part of the stent portion when the stent portion is re-expanded.
8. The prosthetic heart valve of claim 1 , wherein the ring portion includes barbs that engage tissue of the patient when the valve is in use.
9. The prosthetic heart valve of claim 1 , wherein the ring portion is more resistant to annular compression than the stent portion.
10. The prosthetic heart valve of claim 1 , further comprising sheet material covering at least part of the stent portion.
11. The prosthetic heart valve of claim 1 , wherein the stent portion is substantially concentric with the ring portion.