Methods of conditioning sheet bioprosthetic tissue

• US 10,092,399 B2
• Filed: 11/21/2016
• Issued: 10/09/2018
• Est. Priority Date: 03/23/2010
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Edwards Lifesciences Corporation
• Inventors: Dove, Jeffrey S., Tian, Bin, Schneider, Ralph, Cohen, Jeffrey S., Jankovic, Ivan, Migliazza, John F., Wright, Gregory A., Young, James M., Campbell, Louis A.
• Primary Examiner(s): EPPS -SMITH, JANET L
• Application Number:
  US15/357,990
• Publication Number:
  US 20170071731A1
• Time in Patent Office: 687 Days
• Field of Search: 623 213, 600 36, 606 14, 264138, 264299, 435325
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61F 2/02 Prostheses implantable into the body closure means for urethra or rectum or for artificial body openings therefor A61F2/0004
• CPC Class Codes: A61F 2/24 Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
• CPC Class Codes: A61F 2/2409 Support rings therefor, e.g. for connecting valves to tissue annuloplasty rings A61F2/2442
• CPC Class Codes: A61F 2/2415 Manufacturing methods
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2002/30324 differing in thickness
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61L 2300/60 characterised by a special physical form
• CPC Class Codes: A61L 2430/20 for reconstruction of the heart, e.g. heart valves
• CPC Class Codes: A61L 27/3604 characterised by the human or animal origin of the biological material, e.g. hair, fascia, fish scales, silk, shellac, pericardium, pleura, renal tissue, amniotic membrane, parenchymal tissue, fetal tissue, muscle tissue, fat tissue, enamel
• CPC Class Codes: A61L 27/3625 Vascular tissue, e.g. heart valves
• CPC Class Codes: A61L 27/3691 characterised by physical conditions of the treatment, e.g. applying a compressive force to the composition, pressure cycles, ultrasonic/sonication or microwave treatment, lyophilisation
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: B65B 55/18 by liquids or gases B65B55/14 takes precedence
• CPC Class Codes: B65B 63/02 for compressing or compacting articles or materials prior to wrapping or insertion in containers or receptacles

Abstract

Methods for the conditioning of bioprosthetic material employ bovine pericardial membrane. A laser directed at the fibrous surface of the membrane and moved relative thereto reduces the thickness of the membrane to a specific uniform thickness and smoothes the surface. The wavelength, power and pulse rate of the laser are selected which will smooth the fibrous surface as well as ablate the surface to the appropriate thickness. Alternatively, a dermatome is used to remove a layer of material from the fibrous surface of the membrane. Thinning may also employ compression. Stepwise compression with cross-linking to stabilize the membrane is used to avoid damaging the membrane through inelastic compression. Rather, the membrane is bound in the elastic compressed state through addition cross-linking. The foregoing several thinning techniques may be employed together to achieve strong thin membranes.

Claims

1. A method for preparing a bioprosthetic tissue comprising:

treating a bioprosthetic tissue with a first fixative to at least partially fix the tissue;

treating the bioprosthetic tissue with a collagen preserving agent; and

reducing a thickness of a pre-determined portion of the bioprosthetic tissue to produce a contoured bioprosthetic tissue having at least two areas of tissue with different thicknesses from one another, wherein the thickness of one of the at least two areas of tissue is up to twice the thickness of another of the at least two areas of tissue.

2. The method of claim 1, wherein the first fixative is an aldehyde.

3. The method of claim 2, wherein the aldehyde is a glutaraldehyde or a formaldehyde.

4. The method of claim 1, wherein the first fixative is a 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) or a polyethylene glycol.

5. The method of claim 1, wherein the thickness of the pre-determined portion of the bioprosthetic tissue is in the range of about 150 microns to about 250 microns.

6. The method of claim 1, wherein the thickness of the pre-determined portion of the bioprosthetic tissue is about 100 microns.

7. The method of claim 1, wherein the reducing is performed with a laser.

8. The method of claim 7, wherein the laser is a femtosecond laser.

9. The method of claim 1, wherein the collagen preserving agent comprises glycerol.

10. The method of claim 9, wherein the reducing is performed after treating the bioprosthetic tissue with the collagen preserving agent.

11. The method of claim 1, wherein the reducing is performed by removing material from a fibrous side of the bioprosthetic tissue.

12. The method of claim 11, wherein the removing is performed by ablating the fibrous side of the bioprosthetic tissue with a laser.

13. The method of claim 11, wherein the removing is performed by shearing or milling the fibrous side of the bioprosthetic tissue with a mechanical device.

14. The method of claim 1, wherein the reducing is performed by compressing the bioprosthetic tissue.

15. The method of claim 14, further comprising fixing the bioprosthetic tissue during the compressing using a second fixative.

16. The method of claim 1, further comprising forming heart valve leaflets from the bioprosthetic tissue.

17. The method of claim 16, wherein the forming comprises forming the heart valve leaflets to each have a peripheral edge region, a free edge opposite the peripheral edge region, and a central region surrounded by the peripheral edge region and the free edge.

18. The method of claim 16, further comprising attaching the heart valve leaflets to one or both of a skirt or a stent to form a bioprosthetic heart valve.

19. The method of claim 18, further comprising packaging the heart valve in a non-liquid environment.

20. The method of claim 19, further comprising sterilizing the heart valve following the packaging.

31. The method of claim 1, further comprising compressing the bioprosthetic tissue prior to the reducing.

32. The method of claim 31, wherein the compressing is performed during the treating of the bioprosthetic tissue with the first fixative.

33. The method of claim 1, wherein the treating the bioprosthetic tissue with the first fixative is performed prior to the reducing.

21. A method for preparing a bioprosthetic tissue comprising:

treating a bioprosthetic tissue with a fixative to at least partially fix the tissue;

reducing a thickness of a pre-determined portion of the bioprosthetic tissue to produce a contoured bioprosthetic tissue having at least two areas of tissue with different thicknesses from one another, wherein the thickness of one of the at least two areas of tissue is up to twice the thickness of another of the at least two areas of tissue; and

treating the bioprosthetic tissue with one or both of a capping agent and a reducing agent.

22. The method of claim 21, wherein the bioprosthetic tissue is treated with at least the capping agent and wherein the treating the bioprosthetic tissue with at least the capping agent reduces the propensity of the bioprosthetic tissue to calcify in vivo.

23. The method of claim 22, wherein the treating the bioprosthetic tissue with at least the capping agent caps the calcification nucleation sites associated with the bioprosthetic tissue.

24. The method of claim 23, wherein the capping agent is an ethanolamine.

25. The method of claim 23, further comprising treating the bioprosthetic tissue with a collagen preserving agent before the reducing.

26. The method of claim 21, wherein the bioprosthetic tissue is treated with at least the reducing agent and wherein the treating of the bioprosthetic tissue with at least the reducing agent reduces the propensity of the bioprosthetic tissue to calcify in vivo.

27. The method of claim 26, wherein the reducing agent is a borohydride.

28. The method of claim 21, wherein the bioprosthetic tissue is treated with both the capping agent and the reducing agent.

29. The method of claim 28, further comprising treating the bioprosthetic tissue with a collagen preserving agent before the reducing the thickness of the predetermined portion of the bioprosthetic tissue.

30. The method of claim 29, wherein the bioprosthetic tissue is treated with the capping agent and the reducing agent after the reducing.

34. A method for preparing a bioprosthetic tissue comprising:

treating a bioprosthetic tissue with a first fixative to at least partially fix the tissue; and

after the treating, reducing a thickness of a pre-determined portion of the bioprosthetic tissue to produce a contoured bioprosthetic tissue having at least two areas of tissue with different thicknesses from one another.