FLEXIBLE STENT FOR HEART VALVE

• US 3,755,823 A
• Filed: 04/23/1971
• Issued: 09/04/1973
• Est. Priority Date: 04/23/1971
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Warren D. Hancock
• Inventors: Hancock, Warren D.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Frinks, Ronald L.
• Application Number:
  US05/136,832
• Time in Patent Office: 865 Days
• Field of Search: 3/1,DIG.3
• US Class Current: 623/2.18
• CPC Class Codes: A61F 2/2409 Support rings therefor, e.g. for connecting valves to tissue annuloplasty rings A61F2/2442
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: Y10S 623/90 Stent for heart valve

Abstract

An arrangement for heart valves that includes a stent having apexes interconnected by arms, the apexes being deflectable inwardly upon hemodynamic loading of the heart valve for reducing the stress in the valve tissue, the stent being covered by a cloth sleeve which may have an integral bead or flap for attachment to the heart, padding being provided beneath portions of the sleeve for protection, and a reinforcing ring extending around the assembly over the marginal portions of the heart valve, with sutures extending through the reinforcing ring and tissue of the heart valve for forming an attachment to the stent.

Claims

1. A stent for a heart valve comprising a framework of annular configuration, said framework including spaced apical portions extending around the longitudinal axis thereof and arms interconnecting said apical portions, for thereby providing an attachment for the commissures and cusps of a heart valve, said framework including means for permitting substantial resilient deflection of said apical portions inwardly toward said longitudinal axis of said framework such that there is an apical portion so deflected a distance of at least approximately 2 millimeters in response to predetermined loading on said apical portions, which loading is that produced by hemodynamic pressure of approximately 2.3 psi. when a heart valve is mounted on said framework and grafted in the heart of a human, and return of said apical portions to the original positions thereof upon the removal of said predetermined loading.

2. A device as recited in claim 1 in which, for said means for permitting said resilient deflection of said apical portions, said arms are twistable as torsion bars upon the application of said predetermined loading to said apical portions.

3. A device as recited in claim 2 in which said apical portions are relatively rigid so as to be substantially undistorted upon the application of said predetermined loading to said apical portions.

4. A device as recited in claim 2 in which said framework includes additional arms collectively of annular shape, said additional arms being spaced axially from said first-mentioned arms and relatively closer to said apical portions.

5. A device as recited in claim 4 in which said additional arms incline axially away from said apical portions intermediate said apical portions.

6. A device as recited in claim 5 in which said additionAl arms are deflectable to take a permanent set while retaining the resilience thereof for varying the distances thereof from the axis of said framework.

7. A device as recited in claim 6 including in addition means interconnecting said first-mentioned arms and said additional arms for stiffening said additional arms.

8. A device as recited in claim 7 in which said means interconnecting said first-mentioned arms and said additional arms includes members connecting to said additional arms at locations angularly spaced from said apical portions.

9. A device as recited in claim 8 in which said members are substantially at the midpoints of said first-mentioned arms and said additional arms.

10. A device as recited in claim 8 in which said members are in pairs, positioned one on either side of each of said apical portions.

11. A device as recited in claim 10 in which said members of each pair are divergent toward said additional arms.

12. A device as recited in claim 11 in which said framework includes a post interconnecting each of said apical portions and said first-mentioned arms, each of said posts being positioned between said members of each of said pairs.

13. A device as recited in claim 2 in which said framework is constructed of a resilient stainless steel material.

14. A device as recited in claim 2 in which said framework is constructed of a resilient plastic material.

15. A device as recited in claim 14 including in addition a metal ring around the exterior of said framework at the end thereof remote from said apical portions for reinforcing said framework.

16. A device as recited in claim 15 in which said framework includes an annular groove receiving said ring, said groove having an inner surface tapering away from said apical portions so that said ring will not restrict said resilient deflection of said apical portions.

17. A heart valve assembly comprising a stent, said stent including a generally tubular framework having spaced apexes at one end and arms inter-connecting said apexes, said apexes being normally spaced a predeter-mined distance from the longitudinal axis of said framework, a heart valve on said framework, said heart valve having commissures substantially at said apexes and cusps having marginal portions adjacent said arms, and means for attaching said heart valve to said framework, said framework including means for permitting substantial resilient deflection of said apexes inwardly toward said axis a distance of at least approximately 2 millimeters in response to hemodynamic pressure of approximately 2.3 psi. on said heart valve upon grafting of said heart valve in a heart, and return of said apexes to said predetermined distance from said axis upon removal of said hemodynamic pressure.

18. A device as recited in claim 17 in which, for said means for permitting said resilient deflection of said apical portions, said arms are twistable as torsion bars upon the application of said predetermined loading to said apical portions.

19. A device as recited in claim 18 in which said apical portions are relatively rigid so as to be substantially undistorted upon the application of said predetermined loading to said apical portions.

20. A device as recited in claim 17 including in addition a material selected from the group consisting of cloth or sponge means entirely covering said framework.

21. A device as recited in claim 17 including in addition a first material selected from the group consisting of cloth or sponge means, said material including an annular element extending over the marginal edge portion of said heart valve at said one end, said means for attaching said heart valve to said framework including sutures, said sutures extending through said material and said heart valve with loop portions of said sutures engaging said material for thereby preventing said sutures from pulling through the tissue of said heart valve.

22. A device as recited in claim 21 in which said material includes a sleeve entirely receiving said framework so as to provide an inner layer and an outer layer, and including an annular bead on the exterior of said outer layer intermediate the ends thereof for providing a means for attachment to a heart.

23. A device as recited in claim 22 in which said bead is integral with said outer layer, and including a ring of a second material selected form the group consisting of sponge or felt received in said bead.

24. A device as recited in claim 23 in which said first material includes padding between said layers at the locations of said apexes for protecting said sutures and said layers from being abraded by said framework.

25. A device as recited in claim 24 in which said padding includes a layer of felt on both sides of each of said apexes.

26. A device as recited in claim 17 including in addition a material selected from the group consisting of cloth or sponge means, said material including an uninterrupted sleeve entirely receiving said framework so as to provide an inner layer and an outer layer, and an integral generally flat uninterrupted annular flap at the end of said stent opposite from said one end for providing a means for attachment to a heart.

27. A heart valve assembly comprising a stent, said stent including a generally tubular framework having spaced apexes at one end and arms interconnecting said apexes, said arms being inclined away from said apexes at locations intermediate said apexes, a heart valve on said framework, said heart valve having commissures substantially at said apexes and cusps having marginal portions adjacent said arms, an annular member of material selected from the group consisting of cloth or sponge material overlying the marginal edge portion of said heart valve at said one end, and sutures extending through said annular member and said marginal edge portions for attaching said heart valve to said framework, said sutures having loop portions engaging said annular member for thereby protecting said heart valve from damage by said sutures.