Plasma thrombomodulin in orthotopic liver transplantation

Plasma thrombomodulin (TM), a specific marker of vascular endothelial injury was measured pre-, per-, and postoperatively in 16 consecutive patients undergoing orthotopic liver transplantation (OLT). The TM level, which was already elevated preoperatively, remained unchanged during OLT, except for an acute and transitory spike at the time of graft reperfusion. This TM peak is probably attributable to an acute release from the patient's endothelium because the TM level in the last saline rinse of the graft before implantation was low. This TM spike was not correlated with the progressive tissue-type plasminogen activator (t-PA) increase, plasminogen activator inhibitor 1 (PAI-1), or von Willebrand factor (vWF) values. The absence of accumulation of TM in plasma, unlike that of t-PA, suggests that the liver does not play a major role in TM clearance in humans. At the end of surgery, individual TM values returned to preoperative levels and remained unchanged during the 7 days following surgery. This observation suggests that the high (or very high) TM levels measured in these patients might be due to an indirect rather than a direct effect of liver dysfunction on the vascular endothelium which remained damaged during the postoperative period. The possibility that TM might be a predictive marker for thrombotic OLT complications remains to be investigated in a postoperative follow-up study.