Intraoperative evolution of coagulation parameters and t-PA/PAI balance in orthotopic liver transplantation

The changes in coagulation and fibrinolysis were investigated in 10 patients undergoing orthotopic liver transplantation (OLT) which is known to be frequently associated with perturbations of haemostasis. The coagulation profile, already deteriorated before surgery in most patients, showed no appreciable further alteration. On the other hand, important modifications of fibrinolytic parameters occurred, essentially concerning tissue-type plasminogen activator (t-PA) and its specific inhibitor (PAI). t-PA activity constantly increased in the course of transplantation, reaching a maximum at the end of anhepaty. Large interindividual variations were noted in the level of t-PA activity (7.5 to 135 IU/ml). Free PAI activity followed a reverse kinetics, remaining low during the anhepatic stage, and dramatically increasing after allograft reperfusion. Despite the fibrinolytic potential related to high circulating t-PA levels, no biologic nor clinical evidence of systemic fibrinolysis was observed peroperatively. These findings suggest that PAI release could represent an early process making the use of antifibrinolytic drugs during OLT unnecessary.