Claims
- 1. A method for making an access graft comprising a tube of implantable material adapted to be attached in a blood circulatory system and to provide thereby a site for access for cannulation, the tube having a permanent set, kink-resistant U-bend section, the method comprising:
- forming a straight tube by a process which yields a set, dryable tube;
- taking a length of the tube and inserting in the tube along a length of the tube a flexible rod-like support member at least twice;
- wrapping the tube containing the support member around a core so as to define a bent section in the tube while the tube is wet;
- drying the wet tube containing the support member while wrapped around the core and shaping the tube into a bent form;
- removing the dried tube from the core and
- removing the support member so as to form an access graft, U-shaped section.
- 2. A method according to claim 1, which comprises forming the tube by coagulation casting on a former.
- 3. A method according to claim 2, which comprises drying after forming and rewetting the tube before the wrapping step.
- 4. A method according to claim 2, which comprises preventing the tube from drying between the forming of the tube and wrapping the tube.
- 5. A method according to claim 1, which comprises slidably fitting the support in the tube when inserting the support member in the tube.
- 6. A method according to claim 5, wherein the support member comprises one of a silicone coated member and a member coated with a silicone-like substance that does not stick to the tube.
- 7. A method according to claim 1, wherein the core comprises one of a circular and a substantially circular rod-like member having a diameter substantially the same as that of the tube.
- 8. A method according to claim 7, wherein the rod-like member has a helical fin in which the tube is located.
- 9. A method according to claim 8, wherein the wrapping of the tube comprises wrapping the tube twice around the rod-like member.
- 10. A method according to claim 1, which comprises constraining the wrapped, wet tube on the core against movement for drying.
- 11. A method according to claim 1, which comprises drying the tube in an oven at a temperature not exceeding 40.degree. C.
- 12. A method as claimed in claim 10, which comprises hanging a weight to opposite ends of the wet tube so as to constrain the wet tube against movement on the core.
Priority Claims (2)
Number |
Date |
Country |
Kind |
9116563 |
Aug 1991 |
GBX |
|
PCT/GB92/01338 |
Jul 1992 |
WOX |
|
Parent Case Info
This is a continuation-in-part of application Ser. No. 08/182,156, filed Apr. 29, 1994, now abandoned, which was filed as PCT/GB92/01338 on Jul. 21, 1992.
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
55-51545 |
Apr 1980 |
JPX |
WO 8402266 |
Jun 1984 |
WOX |
WO 8901765 |
Mar 1989 |
WOX |
WO 9105522 |
May 1991 |
WOX |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
182156 |
Apr 1994 |
|