Bioprosthetic heart valve

• US 20030167089A1
• Filed: 12/26/2002
• Published: 09/04/2003
• Est. Priority Date: 12/27/2001
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Arbor Surgical Technologies, Inc. (Medtronic Plc)
• Inventors: Lane, Ernest
• Granted Patent: US 7,201,771 B2
• 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 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded

Abstract

A trileaflet biological prosthetic heart valve (11, 41) comprising a thin, rigid annular outer frame (25, 43) which supports three elastic, laminated spring inner frames (18, 57) which in turn provide consistent geometric form and structure for attachment of tissue leaflets (15, 71).

Claims

1. A replacement tissue heart valve, which valve comprises

an annulus having a central passageway,

three generally crescent-shaped struts connected generally near the midpoints thereof to said annulus at angularly spaced locations therealong,

three separate biocompatible flexible leaflets respectively attached to one of each of said struts in locations so as to converge toward one another to close said passageway and to thereafter diverge therefrom to reopen said passageway, each of said leaflets being supported as a stand-alone unit which moves independently of other said leaflets,

said annulus and said struts being covered with biocompatible fabric, and

a sewing ring encircling said annulus.

2. The heart valve according to claim 1 wherein each of said crescent-shaped struts is made from a plurality of pieces of biocompatible metal spring material of sheet form, which individual pieces are juxtaposed with one another as a lamination.

3. The heart valve according to claim 2 wherein said individual pieces of said lamination are physically interconnected to one another within a central region thereof.

4. The heart valve according to claim 3 wherein said laminated crescent-shaped struts include at least three separate crescent-shaped pieces, each of which is of a different length.

5. The heart valve according to claim 2 wherein said laminated crescent-shaped struts have nonlinear spring characteristics which create symmetrical and synchronous leaflet motion.

6. The heart valve according to claim 2 wherein adjacent leaflets are loosely tethered to one another at locations adjacent the ends of said struts and otherwise remain free to move independently.

7. The heart valve according to claim 2 wherein said laminations are connected by anchor pins to said annulus, which pins pass through a marginal portion of said leaflet that is attached to said crescent-shaped strut.

8. The heart valve according to claim 7 wherein said leaflets are sections of bovine pericardial tissue.

9. The heart valve according to claim 8 wherein said tissue is oriented so as to have a resistance to stress and elongation in the circumferential direction at least about 10 to 20% greater than its resistance in the radial direction.

10. The heart valve according to claim 2 wherein said annulus is trefoil-shaped in plan and has an axial profile that is scalloped-shaped at the inlet entrance thereto.

11. The heart valve according to claim 10 wherein said annulus is formed from a cobalt-chromium-nickel alloy strip that is welded into circular form and then stretch-formed in a die to create said trefoil and scalloped shape.

12. The heart valve according to claim 1 that is designed for replacement of a mitral valve wherein said annulus has a generally planar entrance end and a generally planar exit end, which planes are oriented at an angle from about 15°

to about 25°

to each other.

13. The heart valve according to claim 12 wherein the shape of said entrance end of said annulus is generally circular and wherein said exit end of said annulus has of a generally oblong D-shape.

14. The heart valve according to claim 12 wherein elastomeric polymeric rings are affixed to the exterior surface of said annulus at each of said entrance and exit ends which serve as sewing rings and cushion the valve from the remainder of the heart.

15. The heart valve according to claim 14 which is designed to be implanted subannularly in the left atrium cavity, wherein a bovine pericardial tissue skirt surrounds said entrance end, which skirt is proportioned to be attached to the wall of the left atrium to establish an artificial floor therein surrounding the implanted valve.

16. A bioprosthetic heart valve, which valve comprises

an annulus having a central passageway,

three generally crescent-shaped struts connected generally near the midpoints thereof to said annulus at angularly spaced locations therealong, and

three separate biocompatible flexible leaflets respectively attached to one of each of said struts in locations so as to converge toward one another to close said passageway and to thereafter diverge therefrom to reopen said passageway, each of said crescent-shaped struts being made from a plurality of pieces of biocompatible metal spring material of sheet form juxtaposed with one another as a lamination, which individual pieces are connected to one another only at central locations and thus end portions thereof move independently.

17. The heart valve according to claim 16 wherein said laminated crescent-shaped struts include at least three separate crescent-shaped pieces, each of which is of a different length and wherein said laminated crescent-shaped struts have nonlinear spring characteristics which create symmetrical and synchronous leaflet motion.

18. The heart valve according to claim 17 wherein all said pieces of metal spring material have oblong apertures formed therein to provide a desired spring constant and wherein said crescent-shaped piece of metal spring material in each said strut having the greatest length is located radially inward of said other two pieces.

19. The heart valve according to claim 18 wherein adjacent of said pieces having said greatest length are loosely tethered to one another at locations near the tips thereof.