Between December 1985 and April 1990, 50 infants with a variety of congenital cardiac lesions other than the hypoplastic left heart syndrome underwent surgical relief of aortic outflow obstruction by creation of a pulmonary artery to aorta anastomosis. The patients were grouped anatomically by ventriculoarterial alignment. Nineteen had normally aligned great arteries (group I); 25 had transposition of the great arteries, all with a univentricular heart of left ventricular morphology (group II); and 6 had a double-outlet right ventricle (group III). All patients had either aortic stenosis with atresia, subaortic stenosis or a restrictive ventricular septal defect. Sixteen had normal arch anatomy; 34 had arch anomalies consisting of arch hypoplasia (n = 17), coarctation (n = 11), interruption of the arch (n = 4) and complex arch anomalies (n = 2). Surgery was performed at a median age of 10 days (range 2 to 184). Of the 50 infants, 33 survived. No significant difference in early survival (30 days) was noted among the groups of varying ventriculoarterial alignment (68% group I, 72% group II, 83% group III) (p greater than 0.05). Overall actuarial survival was 63% at 18 months. Analysis of actuarial survival by arch anatomy, although not statistically significant, revealed a trend toward better survival at 18 months postoperatively in infants with normal arch anatomy (81%) than in infants with arch anomalies (54%). Of the 33 survivors, 26 have proceeded to the next surgical stage, including the Fontan procedure in 8, superior cavopulmonary anastomosis in 13 and biventricular repair in 5.(ABSTRACT TRUNCATED AT 250 WORDS)