The arterial switch repair and the obstructive right ventricular outflow tract: does it matter?

Right ventricular outflow tract obstruction (RVOTO) was resected in 5 of 78 neonates (6.4%) with complete transposition of the great arteries (TGA) and in 10 of 26 neonates and infants (38.5%) with double outlet right ventricle (DORV) or TGA associated with ventricular septal defect (VSD). The early mortality in the combined series was 7.7%. Morphologic indicators for RVOTO in TGA are abnormal spatial relations of the great arteries, abnormal coronary anatomy, small size of the aortic valve ring, hypoplasia or obstruction of the aortic arch and the presence of a malaligned VSD. Sizing of the RVOT and the aortic valve annulus should confirm the diagnosis and establish the indication for resection. Right ventricular outflow tract obstruction is important for the outcome of arterial switch operation (ASO) in neonates and infants with simple and complex TGA: if subaortic obstruction is anticipated and properly dealt with, the surgical risk of anatomic correction is not increased.