A multicenter study was conducted to test the efficacy and safety of fibrin sealant as a topical hemostatic agent in patients undergoing either reoperative cardiac surgery (redo) or emergency resternotomy. A total of 333 patients from 11 centers in the United States were included in the study. Patients were randomly assigned to initially receive the fibrin sealant or a conventional topical hemostatic agent when such was required during an operation. The end point used to evaluate the agent's efficacy was local hemostasis, the number of bleeding episodes controlled within 5 minutes. The fibrin sealant group from the prospective study was compared with historical matched control subjects for postoperative blood loss, need for resternotomy, blood products received, and hospital stay. It was also compared with historical nonmatched control subjects for the incidence of resternotomy and mortality. The results showed a 92.6% success rate for fibrin sealant in controlling bleeding within 5 minutes of application, compared with only a 12.4% success rate with conventional topical agents (p less than 0.001). Fibrin sealant also rapidly controlled 82.0% of those bleeding episodes not initially controlled by conventional agents. High-volume postoperative blood loss was significantly less (p less than 0.05) in the fibrin sealant group than in the matched controls. Additionally, resternotomy rates after redo operations were significantly lower in the fibrin sealant group (5.6%) than in the nonmatched historical control group (10%) (p less than 0.0089). There were no significant differences in hospital stay or blood products received between the fibrin sealant group and matched historical controls and no difference in mortality between the fibrin sealant group and nonmatched historical controls. There were no documented instances of adverse reactions, transmission of viral infection (hepatitis B, non-A/non-B hepatitis), or human immunodeficiency virus seroconversion. This study shows that fibrin sealant is safe and highly effective in controlling localized bleeding in cardiac operations. Fibrin sealant reduces postoperative blood loss and decreases the incidence of emergency resternotomy. These findings make fibrin sealant a valuable hemostatic agent in cardiac surgery.