Fibrinogen and platelet deposition in PTFE grafts.

The interaction of blood platelets with artificial surfaces such as vascular grafts, seems to be a major contributing factor for the initiation of thrombus formation. A protein co-factor such as fibrinogen may enhance adhesion of platelets to a foreign surface. In the present study we have investigated the temporal relationship of platelet deposition to that of fibrinogen in small PTFE vascular grafts placed into the circulation of dogs. It was found that while platelet adhesion to PTFE grafts seems to be flow dependent below a threshold velocity, fibrinogen deposition is independent of blood flow. Platelet deposition is non-uniformly distributed along the graft surface, with preferential deposition towards the distal anastomosis, while fibrinogen deposition showed a uniform distributional pattern along the graft surface. Platelet deposition appears to occur independent of fibrinogen deposition.