Complete atrioventricular canal malformation: further clarification of the anatomy of the common leaflet and its relationship to the VSD in surgical correction.

Thirty-four heart specimens showing complete atrioventricular (AV) canal malformation were studied. The size of defects underneath the anterior common leaflet was compared with the size of those beneath the posterior common leaflet. Wherever such defects were present, they were either of the same size or larger underneath the anterior leaflet. There was no correlation between the type of posterior common leaflet and the size of ventricular communication. The importance of the location of the ventricular defect in relation to surgical correction, especially in small infants, is discussed.