Prophylaxis of thromboembolic complications after the Fontan operation (total cavopulmonary anastomosis)

Abstract

Thrombotic events have been reported as a major cause of morbidity after the Fontan procedure. There is no consensus concerning the postoperative mode and duration of anticoagulation prophylaxis. In a retrospective study, we evaluated the results of a prophylactic regimen on the basis of the surgical technique, potentially predisposing risk factors, and specific sequelae. We evaluated 142 surviving patients after total cavopulmonary anastomosis (mean follow-up was 91.1 +/- 43.9 months). Prophylactic antithrombotic treatment was initiated in 86 patients with partial prosthetic venous pathway with acetylsalicylic acid; 45 patients with complete autologous tissue venous pathway or partial prosthetic venous pathway received no anticoagulation, and 11 patients received warfarin sodium (Coumadin). During long-term follow-up, 22 patients (12 after acetylsalicylic acid medication) crossed over to warfarin. Thrombotic events occurred in 10 patients (7%), with systemic venous thrombus formation in 8 (5.6%), stroke in 2 (1.4%), and a peak incidence during the first postoperative year. Eight of 10 patients were receiving heparin therapy mainly for prolonged postoperative immobilization. During follow-up, none of the 74 patients receiving acetylsalicylic acid and 1 of 40 patients without medication presented with thrombus formation. Under warfarin medication, 1 of 28 patients had an asymptomatic thrombus. Expected freedom from a thromboembolic event was 92% at 5 years and 79% at 10 years. There was no association with coagulation factor abnormalities. Protein-losing enteropathy was present in 4 of 10 patients. A prophylactic anticoagulation strategy that considers the surgical technique and potential predisposing circumstances proved effective in the prevention of late thrombotic complications after total cavopulmonary anastomosis. There is no need for routine anticoagulation during long-term follow-up after Fontan-type surgery in pediatric patients.