Despite improvements in needles, sutures, and technique, hemorrhage remains a problem in cardiovascular surgery. In this study conventional vascular suture lines and suture lines reinforced with fibrin sealant are compared for blood loss and burst strength. Bilateral femoral arteries in 20 dogs were divided at 50% of their circumference and repaired with six 6-0 polypropylene sutures. Ten animals were systemically heparinized (3 mg/kg), and 10 were not on anticoagulants. The right femoral artery anastomosis was treated with fibrin sealant in all animals, and the left suture line served as the control. Three minutes after initiation of the sealing procedure, blood flow was reinstituted in both femoral arteries. After 3 minutes a significant difference in blood loss between the conventional suture technique and fibrin-reinforced anastomoses was noted in both heparinized (12.1 +/- 2.79 vs. 0.13 +/- 0.06 ml/min; p less than 0.01) and nonheparinized dogs (8.45 +/- 1.37 vs. 0.20 +/- 0.08 ml/min; p less than 0.001). After 30 minutes volume inflow and pressure catheters were inserted into snared compartments encompassing the femoral artery anastomosis. Continuous pressure recordings during volume loading with normal saline solution demonstrated increased bursting pressures of the fibrin-sealed suture lines in both the heparinized (317.5 +/- 13.18 vs. 135 +/- 23.17 mm Hg; p less than 0.001) and nonheparinized animals (474.5 +/- 26.82 vs. 311 +/- 29.31 mm Hg; p less than 0.001). Histologic examination revealed no fibrosis or foreign body reaction and complete resorption of the fibrin sealant within 3 weeks. Fibrin sealant, a powerful hemostatic agent produced from human donors not suffering from hepatitis, decreases blood loss and strengthens suture lines.(ABSTRACT TRUNCATED AT 250 WORDS)