COAGULATION-FACTOR ABNORMALITIES AFTER THE FONTAN PROCEDURE AND ITS MODIFICATIONS

Objective: Recently we reported the prevalence of thromboembolism in p atients who underwent the Fontan procedure and its modifications, Alth ough hemodynamic factors may well contribute to thromboembolism, recen t evidence suggests that coagulation factor abnormalities may also pla y a role, We therefore set out to investigate the coagulation status i n a group of patients who had undergone the Fontan procedure, Methods: The study population consists of 20 children who had undergone the Fo ntan procedure and its modifications, They were examined for coagulati on factor abnormalities, Concentrations of serum albumin, total protei n, and liver enzymes were also measured, The median age at the time of the operation was 6.2 Sears (17 months to 8 years) with a male/female ratio of 2.3:1, The median time from the Fontan repair was 4.9 years (18 to 76 months), Results: Protein C (p < 0.001), protein S (p < 0.02 ), and factor VII (p < 0.001) mere significantly lower than the normal range, The changes in serum albumin and total protein and factors II, IX, and X were not significant, Conclusions: It is possible that defi ciency in protein C, protein S, and factor VII partly account for the prevalence of thromboembolism after Fontan-type repairs. The risk of l ong-term anticoagulation should be weighed against the best palliative procedure for these patients, We suggest that reduced protein C, prot ein S, and factor VII levels in this group of patients should be regar ded as risk factors and that such patients should be treated with anti coagulants.