Anatomic spectrum of abnormal ventriculoarterial connections: surgical implications.

To clarify the salient anatomic features of surgical significance, we investigated 33 specimens representing the spectrum of abnormal ventriculoarterial connections. In those with tetralogy of Fallot or double-outlet right ventricle with subaortic ventricular septal defect, the muscular outlet septum separating the subarterial outflow tracts was always inserted into (or in front of) the anterior limb of the septomarginal trabeculation (septal band). In those having double-outlet right ventricle with doubly committed ventricular septal defect, the outlet septum was lacking. When the ventricular septal defect was in subpulmonary position, with either double-outlet or discordant ventriculoarterial connections, the outlet septum was attached to the posterior limb of the septomarginal trabeculation. The outlet septum was deviated into the subpulmonary outlet in hearts with discordant ventriculoarterial connections and pulmonary stenosis. It is the interrelations between the septomarginal trabeculation, the outlet septum, and the ventriculoinfundibular fold that hold the key to the understanding of surgical anatomy and determine the optimal choice of procedure for definitive biventricular repair.