Porous synthetic vascular grafts with oriented ingrowth channels

• US 7,727,274 B2
• Filed: 02/17/2006
• Issued: 06/01/2010
• Est. Priority Date: 11/23/1998
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Bezuidenhout, Deon, Zilla, Peter
• Primary Examiner(s): Bui; Vy Q
• Application Number:
  US11/357,670
• Publication Number:
  US 20060149358A1
• Time in Patent Office: 1,565 Days
• Field of Search: 623/1.39, 623/1.44, 623/1.23, 623/1.25, 623/1.36, 623/1.45, 623/1.46, 623/1.49, 606/108
• 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 the 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:

extruding a molten polymer, wherein the polymer comprises chopped strands of soluble fibers;

extracting the soluble fibers with an extraction solvent; and

thereafter treating the polymer to effect an open-cell structure having helically oriented interconnected ingrowth channels.

2. The method of claim 1 wherein a blowing agent is used to extrude the molten polymer.

3. The method of claim 2 wherein the blowing agent comprises a physical blowing agent.

4. The method of claim 2 wherein the blowing agent comprises a chemical blowing agent.

5. The method of claim 2 wherein the blowing agent comprises physical and chemical blowing agents.

6. The method of claim 1 wherein the polymer comprises a polyurethane.

7. The method of claim 1 wherein the polymer further comprises reinforcing fibers that are not extractable by the extraction solvent.

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

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

10. The method of claim 1, wherein the treating step is selected from the group consisting of heat treatment, mechanical crushing, infiltrating explosive gas into the cells and igniting the gas, subjecting the extruded polymer to hydrolysis, and combinations thereof.