Neonatal repair of tetralogy of Fallot with and without pulmonary atresia. Our experience with the arterial switch operation for transposition of the great arteries has confirmed the attainability of excellent results with elective neonatal surgery. Up to this time, we have repaired tetralogy of Fallot during the neonatal period only when symptoms, either severe persistent cyanosis or cyanotic spells, have been present. This review assesses the results of such nonelective neonatal correction of tetralogy between 1973 and 1988. Twenty-seven neonates with either symptomatic tetralogy of Fallot or symptomatic tetralogy of Fallot with valvar pulmonary atresia underwent repair. Mean age at repair was 8 +/- 8.4 days and mean weight was 3.0 +/- 0.7 kg. Unsatisfactory palliative shunts had previously been placed elsewhere in four patients. Twenty-five transannular patches and two conduits were used for reconstruction of the right ventricular outflow tract. There were five deaths in the hospital, three of which were due to avoidable technical problems. All deaths occurred in patients with pulmonary artery (Nakata) index less than 150 mm2/m2. One premature child weighing 2.3 kg displayed an absent pulmonary valve-like syndrome after repair and died late of respiratory complications caused by aneurysmal branch pulmonary arteries. Actuarial survival at 5 years was 74%. There was a single rapidly declining hazard phase for death, with the hazard approaching zero at 1 1/2 years after repair. Actuarial freedom from need for reoperation was 76% at 5 years. Postoperative catheterization of 15 long-term survivors showed right ventricular pressure less than 70% systemic in 13 cases. All patients are symptomatically well and functioning in sinus rhythm 1 to 15 years after repair (mean, 5 +/- 4 years). This experience with neonates with symptoms suggests that, if mortality is lower in the absence of symptoms, elective repair of tetralogy of Fallot could be reasonably undertaken during the first months of life. 