Porous synthetic vascular grafts with oriented ingrowth channels

• US 8,187,319 B2
• Filed: 05/14/2010
• Issued: 05/29/2012
• Est. Priority Date: 11/23/1998
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Zilla, Peter Paul, Bezuidenhout, Deon
• Primary Examiner(s): Bui, Vy Q
• Application Number:
  US12/780,098
• Publication Number:
  US 20110213454A1
• Time in Patent Office: 746 Days
• Field of Search: 623/1.39, 623/1.44, 623/1.11, 606/108, 524/495, 264/41
• US Class Current: 623/1.39
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2250/0031 made from both resorbable and non-resorbable prosthetic parts, e.g. adjacent parts
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: B29C 48/022 characterised by the choice of material
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/32 with annular openings, e.g. for forming tubular articles
• CPC Class Codes: B29C 53/587 having a non-uniform wall-structure, e.g. with inserts, perforations, locally concentrated reinforcements
• CPC Class Codes: B29C 53/665 Coordinating the movements of the winding feed member and the mandrel
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/045 with open cells
• CPC Class Codes: B29K 2105/06 containing reinforcements, fillers or inserts
• CPC Class Codes: B29K 2105/101 Oriented
• CPC Class Codes: B29L 2031/7534 Cardiovascular protheses
• CPC Class Codes: C08L 75/04 Polyurethanes

Abstract

A vascular prosthesis is constructed from a structure having interconnected, helically oriented channel-porosity to allow oriented ingrowth of connective tissue into a wall of the prosthesis. The prosthesis can have a small internal diameter of 6 mm or less. Several different methods can be used to produce the prosthesis, including a fiber winding and extraction technique, a melt extrusion technique, and a particle and fiber extraction technique using either a layered method or a continuous method. Furthermore, mechanical properties of prosthesis are matched with mechanical properties of the host vessel, thereby overcoming problems of compliance mismatch.

Claims

1. A method of making a prosthesis comprising the steps of:

preparing a paste comprising a graft material solution and an extractable filler;

depositing a layer of the paste onto a mandrel, wherein the mandrel has a diameter about equal to a desired inside diameter of the vascular graft prosthesis;

winding an extractable fiber onto the layer of paste;

successively depositing additional layers of the paste and winding the extractable fiber onto each layer of the paste until a desired thickness of the vascular graft prosthesis is achieved;

precipitating graft material from the graft material solution; and

extracting the fiber from the graft material.

2. The method of claim 1 wherein the diameter of the mandrel is in a range of 1-20 mm.

3. The method of claim 1 wherein the diameter of the mandrel is in a range of 2-6 mm.

4. The method of claim 1 wherein the thickness of the vascular graft prosthesis is in a range of 0.1-5 mm.

5. The method of claim 1 wherein the thickness of the vascular graft prosthesis is in a range of 0.4-1.5 mm.

6. The method of claim 1 wherein the fiber has a diameter in a range of 10-300 μ

m.

7. The method of claim 1 wherein the fiber has a diameter in a range of 40-110 μ

m.

8. The method of claim 1 wherein the fiber comprises a polymer.

9. The method of claim 1 wherein the graft material comprises a thermoplastic elastomer.

10. The method of claim 1 wherein the graft material comprises a polyurethane.

11. The method of claim 1 further comprising the step of winding a non-extractable, reinforcing fiber onto the paste simultaneously with the winding of the extractable fiber.

12. The method of claim 1 wherein the graft material is precipitated from the graft material solution and the fiber is extracted from the graft material simultaneously.

13. An aortic valve prosthesis made according to the method of claim 1.

14. A vascular graft prosthesis made according to the method of claim 1.

15. A method of making a prosthesis comprising the steps of:

preparing a paste comprising a graft material solution and an extractable filler;

depositing a layer of the paste onto a mandrel, and simultaneously winding an extractable fiber onto the mandrel, until a desired thickness of the vascular graft prosthesis is achieved, wherein the mandrel has a diameter about equal to a desired inside diameter of the vascular graft prosthesis;

precipitating graft material from the graft material solution; and

extracting the fiber from the graft material.

16. The method of claim 15 wherein the diameter of the mandrel is in a range of 1-20 mm.

17. The method of claim 15 wherein the diameter of the mandrel is in a range of 2-6 mm.

18. The method of claim 15 wherein the thickness of the vascular graft prosthesis is in a range of 0.1-5 mm.

19. The method of claim 15 wherein the thickness of the vascular graft prosthesis is in orange of 0.4-1.5 mm.

20. The method of claim 15 wherein the fiber has a diameter in a range of 10-300 μ

m.

21. The method of claim 15 wherein the fiber has a diameter in a range of 40-110 μ

m.

22. The method of claim 15 wherein the fiber comprises a polymer.

23. The method of claim 15 wherein the graft material comprises a thermoplastic elastomer.

24. The method of claim 15 wherein the graft material comprises a polyurethane.

25. The method of claim 15 further comprising the step of winding anon-extractable, reinforcing fiber onto the paste simultaneously with the depositing of the layers of paste and the winding of the extractable fiber.

26. The method of claim 15 wherein the graft material is precipitated from the graft material solution and the fiber is extracted from the graft material simultaneously.

27. An aortic valve prosthesis made according to the method of claim 15.

28. A vascular graft prosthesis made according to the method of claim 15.