 This trial will evaluate the efficacy and safety of the modified Blalock-Taussig shunt MBTS compared to the right ventricle to pulmonary artery RV-to-PA shunt; compare the effect of the MBTS to that of the RV-to-PA shunt on the incidence of death or cardiac transplantation at 12 months post randomization; and compare the effect of the two shunts on intensive care unit ICU morbidity, unintended cardiovascular interventional procedures, right ventricular function, tricuspid valve regurgitation, pulmonary artery growth, and neurodevelopmental outcome. 