Intraoperative hypercoagulability during liver transplantation as demonstrated by thromboelastography

Abstract

Thrombotic complications are more common in liver disease than might be expected because of the coagulopathy described by conventional coagulation tests. Some of these complications may be life-threatening. The phenomenon of hypercoagulation is associated with complications in many populations, but the incidence in liver transplant recipients is unclear. We performed a retrospective database review of intraoperative thromboelastography (TEG) for 124 liver transplant recipients. We assessed the prevalence of hypercoagulation in this group and investigated the relative frequency of both shortened TEG reaction times (R times) and increased net clot strength (G) values. These findings were correlated with thrombotic complications. At the baseline, the prevalence of high G values was 15.53% on native TEG, and the prevalence of shortened R times was 6.80% on native-heparinase TEG. Patients with cholestatic pathologies had particularly high rates of hypercoagulation (42.9% with primary biliary cirrhosis and 85.7% with primary sclerosing cholangitis), but hypercoagulation was also common in patients with fulminant hepatic failure (50%) and nonalcoholic steatohepatitis (37.5%). There was a poor correlation between the TEG R time and the international normalized (INR), with 37.7% of TEG analyses demonstrating a short R time with an INR > 2. Six of the patients developed early hepatic artery thrombosis (5%); 3 of these patients had TEG evidence of high G values (P = 0.25), and 4 had short R times (not significant). In conclusion, intraoperative TEG evidence of high G values and short R times is relatively common in liver transplantation. It is unclear what bearing this condition has on thrombotic complications. Conventional coagulation tests have no ability to diagnose this condition. It is conceivable that such patients may come to harm if hypercoagulability is unrecognized and, therefore, inappropriately managed.