Systemic effects of collagen-impregnated aortoiliac Dacron vascular prostheses on platelet activation and fibrin formation.

To minimize intraoperative blood loss a watertight knitted Dacron aortoiliac prosthesis has been developed by impregnation with bovine collagen. A potential disadvantage is that collagen may be associated with an increase in thrombus formation. We conducted a prospective randomized trial to study the systemic effects of collagen-impregnated prostheses and of aortoiliac operation as such on the coagulation mechanism during the first 10 days after operation. Forty-one patients randomly received either a collagen-impregnated (n = 20) or a nonimpregnated prosthesis (n = 21). Twelve patients who underwent cholecystectomies served as controls. Three markers of the coagulation mechanism were monitored: beta-thromboglobulin, fibrinopeptide A, and fibrin/fibrinogen degradation products. We found no significant differences in median beta-thromboglobulin, fibrinopeptide A, and fibrin/fibrinogen degradation product levels between patients in the collagen-impregnated prosthesis group and patients in the nonimpregnated prosthesis group. This indicates that collagen does not stimulate the coagulation cascade any more than conventional Dacron protheses do. In a comparison of patients who underwent aortoiliac reconstruction and patients who underwent cholecystectomies, the results indicated a significant increased platelet activation and fibrin metabolism in aortoiliac reconstruction group compared with the control group. Finally, we observed a significantly higher preoperative fibrin metabolism in patients with vascular disease than in control subjects. This difference is attributable to the high preoperative fibrin/fibrinogen degradation product values in patients with aortic aneurysms.