A collagen coated fabric vascular prosthesis as a punctureable A-V shunt

A fabric vascular prosthesis sealed with succinylated collagen (SC) was developed as an arteriovenous (A-V) shunt graft for hemodialysis. The SC graft was soft, pliable, flexible, and puncturable, with quick hemostasis. A needle puncture made a smaller hole in the SC graft wall than in a control expanded-polytetrafluoroethylene (e-PTFE) graft such as is usually used for an A-V shunt. The SC graft was extremely hydrous, because it is sealed with water, which is absorbed into the intermolecular spaces of negatively charged collagen. The SC suspension was injected with pressure into a knitted fabric vascular prosthesis wall (water permeability, 1,200 ml) so as to become entangled in the Dacron network. The graft then was lyophilized and thermally cross-linked. Water leakage from six holes created by an 18 G needle puncture in vitro under water pressure of 120 mmHg was 34.5 +/- 29.9 ml/min in the SC graft and 169.9 +/- 38.5 ml/min in the control e-PTFE graft. Hemostatic time at six 18G needle puncture sites on grafts implanted in the abdomen of 12 dogs was 4.5 +/- 2.5 mins in the SC graft and 34.2 +/- 11.5 mins in the control graft. After implantation, the luminal surface of the SC grafts had a thinner thrombus layer than did the control grafts. After 1 week, a thin thrombus layer covered the luminal surface of the SC grafts, and puncture sites were recognized as small dots under it, but in the control grafts, the thrombus layer was thick and the puncture sites could not be seen. These results suggest that the SC graft is less thrombogenic and has less blood leakage from the puncture sites than does the control graft.