Axial-force fixation member for valve

• US 8,348,995 B2
• Filed: 03/23/2007
• Issued: 01/08/2013
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: Medtronic Ventor Technologies LTD. (Medtronic Plc)
• Original Assignee: Medtronic Ventor Technologies LTD. (Medtronic Plc)
• Inventors: Tuval, Yosi, Kilemnik, Ido, Benary, Raphael
• Primary Examiner(s): Isabella, David
• Assistant Examiner(s): Ganesan, Suba
• Application Number:
  US11/726,875
• Publication Number:
  US 20080071366A1
• Time in Patent Office: 2,118 Days
• Field of Search: 623/1.24, 623/1.26, 623/2.12, 623/2.14, 623/2.15, 623/2.16, 623/2.17, 623/2.18, 623/2.19, 623/2.38, 623/2.39, 623/2.4, 623/2.41, 623/2.1, 623/2.11, 623/2.13
• US Class Current: 623/2.1
• 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: A61F 2/2427 Devices for manipulating or deploying heart valves during implantation
• CPC Class Codes: A61F 2/2436 Deployment by retracting a sheath
• CPC Class Codes: A61F 2/2469 with resilient valve members, e.g. conical spiral
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2220/0008 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0071 spherical
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: A61F 2250/0039 differing in diameter

Abstract

A prosthesis is provided for implantation at a native semilunar valve of a native valve complex. The prosthesis includes a distal fixation member, configured to be positioned in a downstream artery, and to apply a first axial force directed toward a ventricle. The prosthesis further includes a proximal fixation member coupled to the distal fixation member, the proximal fixation member configured to be positioned at least partially on a ventricular side of the native valve complex, and to apply a second axial force directed toward the downstream artery, such that application of the first and second forces couples the prosthesis to the native valve complex by axially sandwiching the native valve complex from a downstream side and the ventricular side. A ratio of the first axial force to a radial force applied outwardly by the prosthesis against the native semilunar valve is greater than 1.5:1. Other embodiments are also described.

Claims

1. A prosthesis having a longitudinal axis and for implantation at a native semilunar valve of a native valve complex of a subject, the prosthesis comprising:

a distal fixation member configured to be positioned in a downstream artery of the subject selected from the group consisting of an ascending aorta and a pulmonary trunk, and configured to apply a first axial force directed toward a ventricle of the subject; and

a proximal fixation member coupled to the distal fixation member, the proximal fixation member being configured to be positioned at least partially on a ventricular side of the native valve complex, and configured to apply a second axial force directed toward the downstream artery; and

a valve,

wherein the application of the first and second axial forces couples the prosthesis to the native valve complex by axially sandwiching the native valve complex from a downstream side and the ventricular side thereof,

wherein the prosthesis is configured to be radially compressible to a radially compressed state for delivery to the native valve complex using a catheter and to be self-expandable from the compressed state to a radially expanded state,

wherein the prosthesis is configured to apply the first axial force such that a ratio of (a) the first axial force to (b) a radial force applied outwardly by the prosthesis against the native semilunar valve is greater than 1.5;

1, and

wherein the distal fixation member defines radial boundaries of areas configured to receive native leaflets of the native semilunar valve wherein the distal fixation member comprises exactly three engagement arms extending radially outward from the longitudinal axis, the engagement arms being configured to apply the first axial force.

2. The prosthesis according to claim 1, wherein the prosthesis is configured such that the radial force is less than 0.5 pounds.

3. The prosthesis according to claim 1, wherein the distal fixation member is configured such that the distal fixation member does not press upon native valve commissures of the native semilunar valve upon implantation of the prosthesis.

4. The prosthesis according to claim 1, wherein the prosthesis is configured to apply the first axial force with a force of at least 40 g during diastole.

5. The prosthesis according to claim 1, wherein the prosthesis is configured such that the radial force applied by the prosthesis outwardly against the native semilunar valve is insufficient by itself to chronically maintain the prosthesis in position with respect to the native valve complex under conditions of normal cardiac motion.

6. The prosthesis according to claim 1, wherein the prosthesis is configured, upon implantation thereof, to embrace, without squeezing, leaflets of the native semilunar valve.

7. The prosthesis according to claim 1, wherein the distal fixation member is configured such that it does not fold over leaflets of the native semilunar valve upon implantation of the prosthesis.

8. The prosthesis according to claim 1, wherein the prosthesis is configured to apply the first axial force such that the ratio is greater than 3:

1.

9. The prosthesis according to claim 8, wherein the prosthesis is configured to apply the first axial force such that the ratio is greater than 6:

1.

10. The prosthesis according to claim 1, wherein the proximal fixation comprises at least one barb configured to apply a force to the ventricular side of the native valve complex.

11. The prosthesis according to claim 10, wherein the at least one barb is configured to pierce the ventricular side of the native valve complex.

12. The prosthesis according to claim 10, wherein the at least one barb is configured to protrude into tissue of the ventricular side of the native valve complex, without piercing the tissue.

13. The prosthesis according to claim 1, wherein the proximal fixation member comprises an inner support structure, and wherein the distal fixation member comprises an outer support structure that is placed partially over the inner support structure.

14. The prosthesis according to claim 13, wherein the outer support structure is shaped so as to define a plurality of distal diverging strut supports from which a plurality of proximal engagement arms extend radially outward.

15. The prosthesis according to claim 13, wherein the inner support structure is shaped so as to define a bulging proximal skirt, a portion of which is configured to apply the second axial force.

16. The prosthesis according to claim 1, wherein the engagement arms are configured to extend into respective sinuses of the native valve complex.

17. The prosthesis according to claim 16, wherein the prosthesis further comprises an intermediate portion between the distal fixation member and the proximal fixation member, the intermediate portion being configured to engage an annulus and native leaflets of the native semilunar valve and configured to apply the radial force.

18. The prosthesis according to claim 17, wherein the prosthesis is configured to position native leaflets of the native semilunar valve radially between the engagement arms and the intermediate portion.

19. The prosthesis according to claim 1, wherein the engagement arms define the radial boundaries of areas configured to receive native leaflets of the native semilunar valve.

20. A prosthesis having a longitudinal axis and for implantation at a native semilunar valve of a native valve complex of a subject, the prosthesis comprising:

a distal fixation member configured to be positioned in a downstream artery of the subject selected from the group consisting of an ascending aorta and a pulmonary trunk, and configured to apply a first axial force directed toward a ventricle of the subject; and

a proximal fixation member coupled to the distal fixation member, the proximal fixation member configured to be positioned at least partially on a ventricular side of the native valve complex, and configured to apply a second axial force directed toward the downstream artery; and

a valve,

wherein the prosthesis is configured to be radially compressible to a radially compressed state for delivery to the native valve complex using a catheter and to be self-expandable from the compressed state to a radially expanded state,

wherein the application of the first and second axial forces couples the prosthesis to the native valve complex by axially sandwiching the native valve complex from a downstream side and the ventricular side thereof,

wherein the prosthesis is configured such that a radial force applied by the prosthesis outwardly against the native semilunar valve is insufficient by itself to chronically maintain the prosthesis in position with respect to the native valve complex under conditions of normal cardiac motion, and

wherein the distal fixation member defines radial boundaries of areas configured to receive native leaflets of the native semilunar valve wherein the distal fixation member comprises exactly three engagement arms extending radially outward from the longitudinal axis, the engagement arms being configured to apply the first axial force.

21. The prosthesis according to claim 20, wherein the prosthesis is configured such that the radial force is less than 0.5 pounds.

22. The prosthesis according to claim 20, wherein the distal fixation member does not press upon native valve commissures of the native semilunar valve upon implantation of the prosthesis.

23. The prosthesis according to claim 20, wherein the prosthesis is configured to apply the first axial force with a force of at least 40 g during diastole.

24. The prosthesis according to claim 20, wherein the engagement arms define the radial boundaries of areas configured to receive native leaflets of the native semilunar valve.

25. The prosthesis according to claim 20, wherein the engagement arms are configured to extend into respective sinuses of the native semilunar valve.

26. The prosthesis according to claim 20, wherein the prosthesis further comprises an intermediate portion between the distal fixation member and the proximal fixation member, the intermediate portion being configured to engage an annulus and native leaflets of the native semilunar valve and configured to apply the radial force, and wherein the engagement arms are configured to position the native leaflets of the native semilunar valve radially between the engagement arms and the intermediate portion.