Role of anhepatic time in endothelial-related coagulation in liver transplantation.

BACKGROUND: Disturbances in coagulation homeostasis are common in patients undergoing orthotopic liver transplantation (OLT) and anhepatic period is one of the important factors related to the coagulation abnormalities. The endothelium can regulate hemostasisby producing substances such as thrombomodulin (TM). The primary aim was to evaluate the effect of an hepatic time on the thrombomodulin-protein C system in patients undergoing OLT. METHODS: Fifty patients undergoing OLT were stratified in two groups: anhepatic time ≥ 60 min (N.=18) or anhepatic stage <60 min (N.=32). TM, protein C, activated protein C (APC) and (free) protein S plasma concentrations were measured by enzymelinked immunosorbent assays (ELISA) at the start of the surgery (To); immediately before the anhepatic period (A1); immediately before reperfusion (A2); 5 minutes; 15 minutes; 30 minutes after reperfusion of the graft (R1; R2; R3); at the end of operation (R4); the first day after operation (R5). RESULTS: Blood loss and transfusion were significantly greater in patients whose anhepatic time ≥ 60 min during the operation. TM levels increased most in patients whose anhepatic time ≥ 60 min. Protein C levels remained low throughout the surgery and decreased significantly at other points compared with To (P<0.05). There were no differences in protein C levels between groups except R5. The ratio of circulating APC activity to protein C antigen (APC/PC) increased significantly during the surgery. APC/PC ratio in the neohepatic stage increased significantly in patients whose anhepatic time ≥ 60 min (P<0.05). CONCLUSION: Patients with prolonged anhepatic time had greater changes in the thrombomodulin-protein C system.