We analyzed retrospectively the relationship between coagulation profile, and either hepatic function or hemodynamics, in patients who had undergone a Fontan-type procedure, comparing them, first, with a control group of 12 patients without significant hemodynamic abnormality, and, second, with a group of 14 patients who had not undergone a Fontan procedure, but whose mean right atrial pressure exceeded 8 mmHg. Follow-up catheterization had been performed in all 30 patients submitted to the Fontan-type operation. Prothrombin time, and factor XIII, were significantly lower in those who had undergone the Fontan procedure than in the other groups. Those submitted to the Fontan operation also had lower levels of protein C than controls, and their levels of plasminogen were lower than the patients with high right atrial pressure. Both aspartate aminotransferase and alanine aminotransferase were higher in those undergoing the Fontan procedure than in the other groups, while gamma-glutamyltranspeptidase in these patients was higher than in the control group. Mean right atrial pressure was highest in those under-going the Fontan procedure, while cardiac index was lowest. Prothrombin time was correlated to some extent with aspartate aminotransferase, mean right atrial pressure, and cardiac index. Protein C correlated with both aspartate aminotransferase and mean right atrial pressure, while factor XIII correlated with alanine aminotransferase, mean right atrial pressure, and cardiac index. Aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyltranspeptidase, parameters of hepatic function, correlated significantly with mean right atrial pressure. In those who had undergone the Fontan procedure, decreased synthesis of pro-and anti-coagulant factors is a risk factor for both thrombosis and bleeding. Abnormal hemodynamics, in the absence of a right sided pumping chamber, may predispose to subclinical hepatic dysfunction, leading to selective disturbances of protein synthesis.

The Fontan operation, originally described for the surgical management of tricuspid atresia, is now the final surgery in the strategy of staged palliation for a number of different forms of congenital cardiac disease with a functionally univentricular heart. Despite the improved technical outcomes of the Fontan operation, staged palliation does not recreate a normal physiology. Without a pumping chamber delivering blood to the lungs, the cardiovascular system is less efficient; cardiac output is generally diminished, and the systemic venous pressure is increased. As a result, patients with “Fontan physiology” may face a number of rare but potentially life-threatening complications including hepatic dysfunction, abnormalities of coagulation, protein-losing enteropathy, and plastic bronchitis. Despite the staged palliation resulting in remarkable survival, the possible complications for this group of patients are complex, involve multiple organ systems, and can be life threatening. Identifying the mechanisms associated with each of the rare complications, and developing strategies to treat them, requires the work of many people at many institutions. Continued collaboration between sub-specialists and between institutions will be required to optimise the care for this group of survivors with functionally univentricular hearts.