FIBRINOLYSIS-ADJUSTED PERIOPERATIVE LOW-DOSE APROTININ REDUCES BLOOD-LOSS IN BYPASS OPERATIONS

Background. Postoperative bleeding still remains a serious problem in bypass surgery. This study evaluated fibrinolysis and perioperative lo w-dose antifibrinolytic regimens adjusted to the time course of fibrin olysis. Methods. In a prospective, randomized study of 42 patients und ergoing bypass grafting patients received low-dose aprotinin (group A; n = 14) or low-dose tranexamic acid (group TA; n = 14) intraoperative ly and postoperatively, respectively, With no antifibrinolytics for co mparison (group C; n = 14). Parameters of procoagulation, fibrinolysis , and activated factor VII were measured preoperatively, intraoperativ ely, and postoperatively. Blood loss was determined up to 24 hours. Re sults. The level of thrombin-antithrombin III complex was significantl y decreased postoperatively in the treatment groups (group A and TA ve rsus C: 25 +/- 14 and 19 +/- 10 mu g/L, respectively, versus 40 +/- 21 mu g/L; p < 0.05). Levels of plasmin-antiplasmin complexes were signi ficantly decreased postoperatively in group A (607 +/- 231 mu g/L) ver sus group C (825 +/- 225 mu g/L) (p < 0.05) but were increased in grou p TA (1,145 +/- 394 mu g/L) versus group C (p < 0.05). At all times in traoperatively and postoperatively, levels of D-dimers were significan tly decreased in group A and group TA versus control (p < 0.001), indi cating that fibrinolysis persists after the operation. Intraoperativel y, the factor VIIa level decreased significantly in group A (20 +/- 8 mU/mL) versus group C (31 +/- 15 mU/mL) (p < 0.05), but not in group T A (32 +/- 15 mU/mL). Blood loss was significantly lower in group A (13 5 +/- 37 mL) and group TA (155 +/- 71 mL) versus group C (354 +/- 170 mL) (p < 0.001). Conclusions. This low-dose aprotinin regimen adjusted to perioperative fibrinolysis reduces blood loss significantly in cor onary bypass grafting. For further progress in this subject, clinical investigations of individual fibrinolysis-adjusted antifibrinolytic tr eatment seems warranted. (Ann Thorac Surg 1998;66:792-9) (C) 1998 by T he Society of Thoracic Surgeons.