METHODS FOR MAKING A SUPPORTED GRAFT

• US 20090311132A1
• Filed: 08/24/2009
• Published: 12/17/2009
• Est. Priority Date: 03/10/1995
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Banas, Christopher E., McCrea, Brendan J., Edwin, Tarun J., Kowligi, Rajagopal R.
• Granted Patent: US 8,157,940 B2
• Time in Patent Office: Days
• US Class Current: 422/1
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

A method for forming a self-expanding stent-graft, including coupling a shape memory member to a polymer cladding to form a polymer clad member, winding a length of the polymer clad member about a mandrel so that adjacent windings include regions of polymer cladding that overlap, heating the wound polymer clad member to join and seal the overlapping regions to one another, manipulating the stent-graft from a first diameter to a second diameter smaller than the first diameter, and loading the stent-graft into a restraining sheath, wherein the restraining sheath prevents the stent-graft from reverting to the first diameter.

Claims

1. A method for forming a self-expanding stent-graft, comprising:

coupling a shape memory member to a polymer cladding to form a polymer clad member;

winding a length of the polymer clad member about a mandrel so that adjacent windings include regions of polymer cladding that overlap;

heating the wound polymer clad member to join and seal the overlapping regions to one another;

manipulating the stent-graft from a first diameter to a second diameter smaller than the first diameter; and

loading the stent-graft into a restraining sheath, wherein the restraining sheath prevents the stent-graft from reverting to the first diameter.

2. The method according to claim 1, wherein the coupling step comprises completely surrounding the shape memory member with the polymer cladding.

3. The method according to claim 2, wherein the coupling step comprises coextruding the shape memory wire member with the polymer cladding.

4. The method according to claim 2, wherein the coupling step comprises extruding the polymer cladding with a central lumen dimensioned to receive the shape memory wire member and threading the shape memory member into the central lumen.

5. The method according to claim 1, wherein the coupling step comprises extruding the polymer cladding with a longitudinally extending recess dimensioned to receive and retain the shape memory member and placing the shape memory member into said longitudinally extending recess.

6. The method according to claim 1, wherein the coupling step comprises dip-coating the shape memory member, wherein the polymer cladding is in solvent or aqueous form, and drying the polymer cladding.

7. The method according to claim 1, wherein the coupling step comprises spraying the shape memory member with the polymer cladding in solvent or aqueous form and drying the polymer cladding.

8. The method according to claim 1, wherein the coupling step comprises disposing an adhesive between the shape memory member and the polymer cladding.

9. The method according to claim 1, further comprising the step of bonding the polymer clad member to an inner generally tubular substrate.

10. The method according to claim 1, further comprising the step of bonding the polymer clad member to an outer generally tubular substrate.

11. The method according to claim 1, further comprising the step of disposing the polymer clad member between an inner generally tubular substrate and an outer generally tubular substrate.

12. The method according to claim 11, wherein the inner and outer generally tubular substrates comprise expanded polytetrafluoroethylene.

13. The method according to claim 1, further comprising the step of selecting the polymer cladding material from the group consisting essentially of polytetrafluoroethylene, polyurethane, polyethylene, polypropylene, polyamide, polyimide, polyester, polyfluoroethylenes, silicone, fluorinated polyolefin, fluorinated ethylene/propylene copolymer, perfluoroalkoxy fluorocarbon, ethylene/tetrafluoroethylene copolymer, polyvinylpyrrolidone, and combinations thereof.

14. The method according to claim 1, wherein prior to the coupling step, the step of preparation of the shape memory member comprises:

winding the shape memory member about a shaping mandrel;

imparting shape memory characteristics to the shape memory member by heating at a temperature to achieve generally an austenite phase of the shape memory material;

cooling the shape memory member to a temperature to achieve generally a martensite phase of the shape memory material; and

straightening the shape memory member.

15. The method according to claim 1, wherein the manipulating comprises exposing the stent-graft to a temperature below the austenite temperature of the shape memory member and deforming the stent-graft.

16. The method according to claim 15, wherein the deforming step is selected from the group consisting essentially of manually deforming the stent-graft, drawing the stent-graft through a die, folding the stent-graft, and combinations thereof.

17. The method according to claim 16, further comprising sterilizing the stent-graft.

18. The method according to claim 1, further comprising sterilizing the stent-graft.