Methods of conditioning sheet bioprosthetic tissue

• US 9,498,288 B2
• Filed: 07/24/2013
• Issued: 11/22/2016
• 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, Campbell, Louis A.
• Primary Examiner(s): EPPS -SMITH, JANET L
• Application Number:
  US13/950,154
• Publication Number:
  US 20130310929A1
• Time in Patent Office: 1,217 Days
• Field of Search: 264/138, 264/299, 623/2.13
• US Class Current: 1/1
• 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 bioprosthetic tissue comprising:

providing a tissue having a first thickness;

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

contouring the tissue to reduce the thickness of a pre-determined portion of the tissue to a second thickness, the contoured tissue having at least two areas having different thickness profiles;

wherein the treating is performed before, during and/or after the contouring.

2. The method of claim 1, wherein the first thickness is about 250-700 microns.

3. The method of claim 2, wherein the second thickness is about 150-250 microns.

4. The method of claim 2, wherein the second thickness is about 100 microns.

5. The method of claim 1, wherein the first fixative is glutaraldehyde.

6. The method of claim 1, further comprising treating the tissue with a second fixative.

7. The method of claim 6, wherein the second fixative is selected from the group consisting of:

di- or poly-amine material, linear or branched polyethyleneimine, polyvinyl alcohol, and Jeffamine.

8. The method of claim 1, further comprising cutting the tissue into one or more heart valve leaflets.

9. The method of claim 8, wherein the tissue is cut after the contouring.

10. The method of claim 8, wherein the tissue is cut before the contouring.

11. The method of claim 8, wherein the heart valve leaflets each comprise a peripheral region surrounding a central region.

12. The method of claim 11, wherein at least a portion of the peripheral region is thicker than the central region.

13. The method of claim 12, wherein the thicker peripheral region transitions to the thinner central region in a step or a gradual ramp.

14. The method of claim 8, wherein the heart valves each comprise a curved cusp edge, a free edge opposing the curved cusp edge and a central region.

15. The method of claim 14, wherein a triple point area in the middle of the free edge is thicker than the central region.

16. The method of claim 14, further comprising a plurality of radial strips extending from the middle of the free edge to the curved cusp edge, the radial strips having a thickness that is greater than the thickness of the central region surrounding the radial strips.

17. A bioprosthetic heart valve comprising a bioprosthetic tissue prepared in accordance with claim 1.