Expandable medical implant and percutaneous delivery

• US 20030191528A1
• Filed: 06/17/2002
• Published: 10/09/2003
• Est. Priority Date: 06/02/2000
• Status: Active Grant

• Current Assignee: Medtronic 3F Therapeutics, Inc. (Medtronic Plc)
• Original Assignee: 3F Therapeutics Incorporated (Medtronic Plc)
• Inventors: Tu, Hosheng, Quijano, Rodolfo C.
• Granted Patent: US 6,805,711 B2
• Time in Patent Office: Days
• US Class Current: 623/2.37
• CPC Class Codes: A61F 2/2448 D-shaped rings
• CPC Class Codes: A61F 2250/0004 adjustable
• CPC Class Codes: A61F 2250/0082 specially designed for children, e.g. having means for adjusting to their growth

Abstract

An expandable annular ring for implantation in a valvular annulus and its percutaneous use thereof comprises a plurality of stenting elements made of a first shape-memory material having a first shape-transition temperature, wherein the first shape-memory material expands to a preshape when the first shape-memory material is heated to above the first shape-transition temperature; and a plurality of anchoring elements made of a second shape-memory material having a second shape-transition temperature that is higher than the first shape-transition temperature, wherein the second shape-memory material expands to the second preshape when the second shape-memory material is heated to above the second shape-transition temperature.

Claims

1. An expandable annular ring with a uni-flow mechanism for implantation in a valvular annulus of a patient comprising a plurality of stenting elements evenly spaced along said annular ring, wherein said stenting elements are made of a shape-memory material, the shape-memory material having a preshape and a shape-transition temperature, wherein the shape-memory material expands to its preshape so as to expand the annular ring when said shape-memory material is heated to above the shape-transition temperature.

2. The expandable annular ring with a uni-flow mechanism according to claim 1, wherein said shape-memory material is selected from a group consisting of shape-memory Nitinol, shape-memory plastic, and combination thereof.

3. The expandable annular ring with a uni-flow mechanism according to claim 1, wherein said uni-flow mechanism comprises a plurality of valvular cusps configured for allowing fluid to flow through the annular ring in one direction.

4. The expandable annular ring with a uni-flow mechanism according to claim 1, wherein the shape-transition temperature for said shape-memory material is between about 39°

C. and about 90°

C.

5. An expandable annular ring for implantation in a valvular annulus comprising:

a plurality of stenting elements made of a first shape-memory material having a first preshape and a first shape-transition temperature, wherein the first shape-memory material expands to the first preshape when said first shape-memory material is heated to above the first shape-transition temperature; and

a plurality of anchoring elements made of a second shape-memory material having a second preshape and a second shape-transition temperature that is higher than the first shape-transition temperature, wherein the second shape-memory material expands to the second preshape when said second shape-memory material is heated to above the second shape-transition temperature.

6. The expandable annular ring according to claim 5, wherein said first and second shape-memory materials are selected from a group consisting of shape-memory Nitinol, shape-memory plastic, and combination thereof.

7. The expandable annular ring according to claim 5 further comprising a uni-flow mechanism for allowing fluid to flow through said annular ring in one direction.

8. The expandable annular ring according to claim 5, wherein said plurality of stenting elements are evenly spaced along said annular ring configured for enabling essentially uniform ring distension in a circumferential direction when said first shape-memory material is heated to above the first shape-transition temperature.

9. The expandable annular ring according to claim 5, wherein the first shape-transition temperature is between about 39°

C. and about 90°

C.

10. The expandable annular ring according to claim 5, each anchoring element comprising a distal end and a proximal end, wherein the proximal ends of said anchoring elements are secured at an periphery of the annular ring configured for enabling the distal ends of said anchoring elements positioning in a radially outward direction when said second shape-memory material is heated to above the second shape-transition temperature.

11. The expandable annular ring according to claim 5, wherein the second shape-transition temperature is between about 40°

C. and about 90°

C.

12. The expandable annular ring according to claims 5 and 7, wherein said first shape-memory material is embedded within a biocompatible substrate selected from a group consisting of silicone, polyurethane, expanded polytetrafluoroethylene, semi-permeable material, biodegradable material, collagen, and mixture of said biocompatible substrate thereof.

13. The expandable annular ring according to claim 12 further comprising a therapeutic agent loaded within said biocompatible substrate.

14. The expandable annular ring according to claims 13, wherein the therapeutic agent is heparin.

15. The expandable annular ring according to claims 13, wherein the therapeutic agent is an anti-inflammatory agent.

16. The expandable annular ring according to claims 13, wherein the therapeutic agent is an antibiotics.

17. The expandable annular ring according to claims 13, wherein the therapeutic agent is an anti-proliferative agent.

18. A method for implanting an expandable annular ring having a plurality of stenting elements made of a first shape-memory material with a first shape-transition temperature and a plurality of anchoring elements made of a second shape-memory material with a second shape-transition temperature that is higher than the first shape-transition temperature in a valvular annulus of a patient, the method comprising steps of:

(a) delivering said annular ring to the valvular annulus;

(b) expanding said annular ring to intimately contact an inner wall of the valvular annulus by heating the first shape-memory material above the first shape-transition temperature; and

(c) deploying the anchoring elements to penetrate into a surrounding annulus tissue by heating the second shape-memory material above the second shape-transition temperature.

19. The method according to claims 18, wherein the annular ring further comprises a uni-flow mechanism that allows fluid to flow through said annular ring in one direction.

20. The method according to claims 18, wherein the step for delivering said annular ring to the valvular annulus is through a percutaneous opening of the patient.