RELEASE OF VON-WILLEBRAND-FACTOR BY CARDIOPULMONARY BYPASS, BUT NOT BY CARDIOPLEGIA IN OPEN-HEART-SURGERY

von Willebrand Factor (vWF) is released from endothelial cells. Increa sed vWF in the coronary circulation during cardiac surgery could be a potential indicator of coronary endothelial injury or stimulation, and thus a possible tool to evaluate regimens of myocardial protection. R elease of vWF was investigated in 12 patients undergoing coronary arte ry bypass surgery with cardiopulmonary bypass (CPB). Concomitant sampl es of arterial and coronary sinus blood for measurement of vWF (antige n method) were drawn before start of CPB and 1, 4, 10 and 30 min after release of the aortic cross clamp. Additional arterial samples were d rawn pre-, per-, and postoperatively. Preoperative arterial vWF was 1. 58+/-0.59 IU/ml (mean +/- SD), and increased during CPB (highest level 2.37+/-0.76 IU/ml, p<0.0026). No difference between arterial and coro nary sinus vWF levels was found. Arterial vWF increased further the fi rst postoperative day (3.96+/-0.92 IU/ml, p<0.0026). In conclusion, sy stemic vWF is increased during CPB, and may be a possible marker of en dothelial injury/activation to evaluate deleterious effects of differe nt equipment for CPB. Reperfusion of the ischaemic, cardioplegic heart did not release vWF in the coronary circulation.