Decision making in the definitive repair of the heart with a small right ventricle.

Data from 51 patients with small right ventricle who underwent a definitive repair were analyzed retrospectively. The repair was considered complete (29 patients) when it resulted in relief of the right ventricular outflow tract obstruction by closure of intracardiac (atrial septal defect) and extracardiac (when present) shunts. The repair was considered a definitive palliation when the intracardiac and the extracardiac shunts were left open (11 patients). A complete separation of the systemic and pulmonary circulations was established with the use of the Fontan procedure in another 11 patients. The outcome in these patients correlated with the preoperative size of the right ventricular cavity as assessed by measurement of the tricuspid valve diameter and by consideration of the right ventricular morphology (based on the tripartite right ventricular concept). If the tricuspid valve of a tripartite right ventricle has a diameter above the lower 99% confidence limit of the normal mean it can be safely incorporated in a complete repair (p less than .01). This also applies for a right ventricle without a trabecular portion, provided the criteria of the Fontan operation are fulfilled. Right ventricles with tricuspid valve diameters smaller than the lower 99% confidence limit of the normal mean cannot sustain total pulmonary blood flow. Definitive palliation should be reserved for use in patients whose right ventricles are too small for complete repair and who are not suitable candidates for Fontan's procedure.