Heart valve prosthesis

• US 20080154358A1
• Filed: 07/28/2007
• Published: 06/26/2008
• Est. Priority Date: 07/28/2006
• Status: Abandoned Application

• Current Assignee: Geoffrey Tansley, Seyed Mohammed Ali Mirnajafi Zadeh
• Original Assignee: Geoffrey Tansley, Seyed Mohammed Ali Mirnajafi Zadeh
• Inventors: Zadeh, Seyed Mohammed Ali Mirnajafi, Tansley, Geoffrey
• Application Number:
  US11/878,953
• Publication Number:
  US 20080154358A1
• Time in Patent Office: Days
• US Class Current: 623/2.14
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2/2415 Manufacturing methods

Abstract

A heart valve prosthesis 4 for human implantation fabricated from bovine pericardial material which is harvested from a region of incipient low calcium content or other material, wherein pre-forming and fixing of the leaflets 5 of the valve to create a rapid change in direction of the surface modifies the stresses within the material leading to a reduction of the peak tensile stress magnitude and concomitant in-use calcification thereby to increase longevity of the valve,

Claims

1. A heart valve prosthesis for use in human patients comprising:

at least one cusp capable of functioning as a valve;

wherein the cusp is flexible;

wherein the heart valve prosthesis is constructed of at least a significant proportion of biological tissue;

wherein the cusp is fixed so as to retain residual stresses.

2. The heart valve prosthesis of claim 1 wherein the residual stresses within the cusp reduce maximum tensile stresses within the cusp when the cusp is in an open position.

3. The heart prosthesis of claim 2 wherein the residual stresses are introduced into a region of the cusp selected from the group consisting of a commissural region, a stent area and a belly region of the cusp.

4. The heart valve prosthesis of claim 3 wherein the cusp has a region angularly protruding from an outer edge of the cusp and wherein a surface of the cusp has a rapid change in direction so as to retain the residual stresses.

5. The heart valve prosthesis of claim 1 wherein the biological tissue can include bovine pericardium tissue.

6. The heart valve prosthesis of claim 1 wherein the biological tissue can include xeno-transplanted pericardial tissue.

7. The heart valve prosthesis of claim 1 wherein the biological tissue can include xeno-transplanted valve tissue.

8. The heart valve prosthesis of claim 1 wherein the biological tissue can include transplanted human valve or dura mater tissue.

9. The heart valve prosthesis of claim 1 wherein the heart valve prosthesis is attached to a patient'"'"'s circulatory system by a sewing ring.

10. The heart valve prosthesis of claim 1 wherein the heart valve prosthesis can be attached to a patient'"'"'s circulatory system by a stent device.

11. The heart valve prosthesis of claim 1 wherein the bovine pericardium tissue is selectively harvested from a predetermined region of a bovine pericardial sack so as to reduce innate calcium concentration present in the biological tissue.

12. The heart valve prosthesis of claim 1 wherein the biological tissue is fixed in glutaraldehyde.

13. A heart valve prosthesis for use in human patients comprising:

at least one cusp capable of functioning as a valve;

wherein the cusp is flexible;

wherein the heart valve prosthesis is constructed of at least a significant proportion of biological tissue;

wherein the cusp can open and close to allow a flow of blood in use;

wherein the biological tissue is selectively harvested from tissue that is low in innate calcium concentration.

14. The heart valve prosthesis of claim 13 wherein the region of the bovine pericardial sack is determined by a region designated at position number 13 in FIG. 2 of the accompanying drawings.

15. The heart valve prosthesis of claim 14 wherein the cusp is fixed so as to introduce residual stresses within the cusp when the cusp is in a closed position so as to reduce tensile stresses in the cusp when the cusp is in an open position.

16. The heart valve prosthesis of claim 15 wherein the residual stresses are introduced into a region of the cusp selected from the group consisting of a commissural region, a stent area and a belly region of the cusp.

17. The heart valve prosthesis of claim 13 wherein the biological tissue can include bovine pericardium tissue.

18. A heart valve prosthesis for use in human patients comprising:

at least one cusp capable of functioning as a valve;

wherein the cusp is flexible;

wherein the heart valve prosthesis is constructed of at least a significant proportion of polymeric material;

wherein the cusp is formed so as to introduce residual stresses within the cusp when the cusp is in a partially open position, so as to reduce tensile stresses in the cusp when the cusp is in an open position.

19. The heart valve prosthesis of claim 18 wherein the residual stresses are introduced into a region of the cusp selected from the group consisting of a commissural region, a stent area, a belly region of the cusp.

20. The heart valve prosthesis of claim 18 wherein the cusp has a region angularly protruding from an outer edge of the cusp and wherein a surface of the cusp has a rapid change in direction so as to retain the residual stresses.