Repair of unbalanced atrioventricular septal defect with small right ventricle

A 2-month-old boy with trisomy 21, a small right ventricle, and an unbalanced atrioventricular septal defect underwent successful biventricular repair without atrial fenestration. We decided to perform leftward partitioning of the atrioventricular valve to widen the right ventricle inflow tract. This procedure increases the size of the right-sided valve and allows full function of the right ventricle without an atrial communication. This technique should be employed in patients with a small right ventricle and an unbalanced atrioventricular septal defect, as an alternative to atrial septal fenestration or univentricular palliation.