Method of manufacturing a radially-enlargeable PTFE tape-reinforced vascular graft

A method for manufacturing a radially expandable, tape-reinforced, tubular vascular graft formed substantially of sintered PTFE, the method comprising the steps of:

• a) providing a tubular base graft formed of expanded PTFE, said tube having a first end, a second end, an outer surface, and a lumen extending longitudinally therethrough and having a first lumenal diameter;
• b) sintering the tubular base graft;
• c) providing a PTFE reinforcement tape comprising an expanded PTFE film;
• d) sintering the reinforcement tape;
• e) inserting a first rigid mandrel into the lumen of the tubular base graft, the first rigid mandrel having an outer diameter which is substantially equal to the first lumenal diameter of the tubular base graft;
• f) spirally wrapping the reinforcement tape about the outer surface of the tubular base graft to form a tape-reinforced graft;
• g) heating the tape-reinforced graft to a temperature above 327.degree. C. for a sufficient period of time to cause the reinforcement tape to laminate to the outer surface of the tubular base graft;
• h) removing the first mandrel from the lumen of the tape-reinforced graft;
• i) inserting a second rigid mandrel into the lumen of the tape-reinforced graft, the second rigid mandrel having an outer diameter which is smaller than the first lumenal diameter of the lumen of the tape-reinforced graft;
• j) longitudinally restraining the tape-reinforced graft;
• k) again heating the tape-reinforced graft to a temperature sufficient to cause the tape-reinforced graft to shrink radially until its lumenal diameter is substantially the same as the outer diameter of the second rigid mandrel, and from which the tape-reinforced graft may be subsequently radially enlarged to return the lumenal diameter of the tape-reinforced graft to the first lumenal diameter.

A method for manufacturing a radially enlargeable tape-reinforced tubular vascular graft, comprising the steps of:

• a) providing a tubular base graft having an outer surface and a hollow lumen extending longitudinally therethrough, the tubular base graft being formed substantially of a fluoropolymer material;
• b) sintering the tubular base graft so that the outer surface has a first diameter after sintering;
• c) providing a reinforcement tape wound around the outer surface of the tubular base graft, the reinforcement tape comprising a film formed substantially of fluoropolymer material;
• d) sintering the fluoropolymer tape;
• e) affixing the fluoropolymer tape to the outer surface of the tubular base graft to form a workpiece;
• f) longitudinally restraining the workpiece while heating the workpiece, thereby causing the tubular base graft to assume a radially shrunken state with its outer surface having a second diameter which is smaller than the first diameter, and from which the tubular base graft may be subsequently radially enlarged to return to the first diameter.

A method of manufacturing a radially enlargeable tape-reinforced tubular vascular graft, the method comprising the steps of:

• a) forming a tape-tube by wrapping an expanded, sintered fluoropolymer tape about a rigid mandrel and subsequently heating the tape to form the tape-tube, the tape-tube having a first diameter after sintering;
• b) radially shrinking the tape-tube to a second diameter smaller than the first diameter by further heating while preventing the tape-tube from undergoing longitudinal shortening;
• c) coaxially positioning a tubular base graft formed of expanded sintered fluoropolymer within the tape-tube;
• d) causing the tape-tube to become affixed to the base graft, thereby forming the radially enlargeable tape-reinforced tubular vascular graft.

A method of manufacturing a radially enlargeable tape-reinforced tubular vascular graft, the method comprising the steps of:

• a) providing an expanded fluoropolymer tape;
• b) sintering the fluoropolymer tape and forming the tape into a tape tube, the tape tube having a first diameter after sintering;
• c) longitudinally restraining the fluoropolymer tape tube;
• d) subsequently heating the fluoropolymer tape tube to cause the fluoropolymer tape tube to assume a radially shrunken state having a second diameter which is smaller then the first diameter, and from which the fluoropolymer tape tube may be subsequently enlarged to return to the first diameter;
• e) providing a tubular base graft formed of expanded fluoropolymer, the tubular base graft having a lumen and an outer surface;
• f) inserting the tubular base into the shrunken, expanded, sintered fluoropolymer tape tube;
• g) heating the fluoropolymer tape tube and tubular base graft to cause the tape tube to become affixed to the outer surface of the tubular base graft.