ATRIAL THROMBUS AFTER THE FONTAN-OPERATION - PREDISPOSING FACTORS, TREATMENT AND PROPHYLAXIS

Thrombosis of the right side of the heart has previously been a rarely reported early or late postoperative complication after a modified Fo ntan-procedure. In 4 (5.5 %) of 72 surviving patients who underwent a total cavopulmonary connection for various forms of univentricular atr ioventricular connection or other complex lesion a thrombus within the right atrium was diagnosed by transthoracic echocardiography either e arly (in 3 cases) or late (in one case) postoperatively. Predisposing haemodynamic abnormalities could be identified in all four patients, b ut no patient was found to have severe abnormalities of coagulation. T wo patients presented with acute clinical symptoms on the third and tw elfth day after initial surgery. They underwent emergency reoperation with thrombectomy followed by prophylactic treatment with coumadin or aspirin after initial heparinization. In the other 2 patients, routine postoperative echocardiography revealed a right atrial thrombus witho ut specific clinical symptoms 25 days or 3 months postoperatively. Thr ombolytic therapy with an initial bolus of tissue plasminogen activato r (0.1 mg/kg) followed by continuous infusion (1 mg/kg/day) combined w ith heparinization yielded complete resolution of the thrombus after 2 7 and 40 hours, respectively, as demonstrated on follow-up echocardiog rams. Our own experience, coupled with a review of the literature, ind icate that prophylactic anticoagulation therapy with coumadin should c ontinue for at least 4 to 6 months for patients with an increased risk for postoperative thrombosis. For infants and young children with a l ow risk for postoperative thrombosis, aspirin should be given routinel y for 6 months postoperatively.