COAGULATION AND FIBRINOLYSIS SYSTEM IN AORTIC-SURGERY UNDER DEEP HYPOTHERMIC CIRCULATORY ARREST WITH APROTININ - THE IMPORTANCE OF ADEQUATEHEPARINIZATION

Background Coagulation and fibrinolysis parameters were compared betwe en two strategies of heparinization during cardiopulmonary bypass (CPB ) in patients who underwent aortic surgery with deep hypothermic circu latory arrest (DHCA) and retrograde cerebral perfusion (RGCP) with apr otinin. Methods and Results From January 1993 to January 1996, 94 pati ents underwent aortic surgery with DHCA with aprotinin; replacement of the ascending aorta took place in 14 patients, arch in 69, and descen ding aorta in 11. Two million units of aprotinin was administrated in the priming of CPB, and 3 mg/kg heparin was given before CPB. During C PB, 49 patients had an additional 1 mg/kg/h heparin regardless of acti vated clotting time (ACT) [group A], whereas 45 patients had an additi onal 1 mg/kg/h heparin when ACT was less than 500 seconds [group B]. A CT, PT, aPTT, fibrinogen, AT-3, plasminogen, alpha 2-PI (plasmin inhib itor), fibrin/fibrinogen degradation products (FDP), DD (D dimer), TAT (thrombin-antithrombin complex), PIC (plasmin-plasmin inhibitor compl ex), beta-TG (thromboglobulin), and PF-4 (platelet factor-4) were assa yed. No difference was detected between the two groups regarding the d uration of operation, CPB, aortic cross-clamping, DHCA, RGCP, and time from the end of CPB to admission to ICU. The heparin dose was greater in group A, but the protamine dose was similar. There was no differen ce in bleeding after perfusion or in ICU. Levels of TAT, fibrinogen, a nd DD were lower in group A. PIC, alpha-PI, and FDP value showed no di fference. PF-4 and beta-TG were lower in group A, and the platelet cou nt at the end of operation and the day after the operation was higher in group A. Conclusions Platelets were better preserved and activation of the coagulation system during CPB was less seven in patients who h ad a regular additional constant heparin regimen irrespective of ACT i n surgery for the aortic aneurysm with DHCA and aprotinin usage. An ac curate monitoring system for heparinization is necessary to maintain a ppropriate anticoagulation during CPB in patients who are undergoing a ortic surgery with DHCA using aprotinin.