Surgical treatment of critical right ventricular outflow tract obstruction with intact ventricular septum in infancy.

Between December 1965 and August 1981, a total of 104 operations were performed on 101 infants for treatment of critical right ventricular outflow tract obstruction with intact ventricular septum (RVOTO/IVS). Twenty-three patients had pulmonary atresia (PA/IVS) and 78 critical pulmonary stenosis (CPS/IVS). One of those had an emergency reoperation within the first year of life because of acquired atresia after valvotomy. The cumulative early 30 days mortality was 35.6% (58.3% for PA/IVS and 28.7% for CPS/IVS). Analysis of this series indicates that the surgical risk does not significantly differ in PA/IVS and CPS/IVS within the same age group. Patients with small right ventricular cavity, dictating surgery within the first 30 days of life, present significantly higher surgical risk in both groups. The higher overall mortality in PA/IVS may be influenced by the lower median age at operation. Our present surgical indications are the following. Patients with normal sized right ventricle are treated with pulmonary valvotomy at any age. Patients with small sized right ventricle undergo early total correction over 6 months of age. Under 30 days of life balloon atrial septostomy, valvotomy and systemic-to-pulmonary artery shunt are performed. Between one and 6 months the surgical technique depends upon the clinical presentation and the right ventricular anatomy in the single patient. Since this policy of treatment has been pursued, in the last 12 consecutive cases the 30 days mortality was 8.3%.