The arterial switch operation (Jatene procedure) is the treatment of choice for transposition of the great arteries with intact ventricular septum (TGA-IVS) in neonatal age, because of the low mortality and morbidity during long term follow up.1 Right ventricular outflow obstruction is the most frequent postoperative complication,2-4 occurring with sufficient severity to require reintervention in up to 10% of cases.1 ,5Usually, the obstruction is either at the level of the pulmonary trunk or pulmonary bifurcation and, more uncommonly, in the right ventricular infundibulum. Conversely, right ventricular outflow obstruction resulting from late onset pulmonary valve stenosis (previously aortic valve) is exceedingly rare.6

We report two neonates who had the arterial switch procedure, in whom right ventricular outflow tract obstruction caused by neopulmonary …