Fontan's procedure in two stages.

Since 1985, 381 patients with various cardiac malformations that share the central common feature of only one effective ventricle have been treated with some modification of Fontan's operation. Since 1989, the Fontan operation has been staged by associating the superior vena cava with the branch pulmonary arteries (hemi-Fontan) initially followed, some months later, by associating the inferior vena cava to the branch pulmonary arteries (completion Fontan). The difference in early mortality for a primary-Fontan operation (16%) compared with a completion-Fontan operation (7%) is substantial (p < 0.05). Since January 1991, mortality associated with the hemi-Fontan operation has been 5.5% (7 deaths in 127 patients). A systematic staged approach to Fontan's operation has been undertaken with a hemi-Fontan operation in patients who are 6 months of age and a completion Fontan operation when those patients are 12 to 18 months of age in an effort to reduce the volume load of the ventricle as early as possible, to minimize intermediate mortality from the palliated state, and to reduce the impact of rapid changes in ventricular geometry and diastolic function that can accompany either the hemi-Fontan or primary Fontan operation, but that are lethal only after a primary Fontan operation.