From June 1986 to May 1994, 25 patients underwent the Rastelli operation for complete transposition of the great arteries with ventricular septal defect and pulmonary stenosis or atresia. Fourteen patients whose tricuspid valve chordae were normal underwent the conventional Rastelli procedure (conventional group), whereas 11 patients who had tricuspid malinsertion into the infundibular septum underwent the Rastelli operation concomitant with mobilization of the infundibular septal flap, with the tricuspid valve chordae, to the right ventricular side of the intraventricular conduit (conal flap method) (conal flap group). In relation to the mobilization of the tricuspid valve chordae, right heart function and tricuspid regurgitation were compared between the two groups. There was one early death after the conventional Rastelli procedure and no early death after the Rastelli operation with a conal flap. There was one late death in the conventional group and two late deaths in the conal flap group. The mean follow-up was 50.8 +/- 5.1 months in the conventional group and 54.9 +/- 7.5 months in the conal flap group (p = 0.43). Reoperation was necessary for 1 patient in the conal flap group during follow-up. At the most recent follow-up, all patients in both groups were in New York Heart Association functional class I. Tricuspid regurgitation was estimated from the echocardiograms. Mild to moderate regurgitation was noted in 6 patients in the conventional group and 8 in the conal flap group. However, postoperative right heart catheterization data did not show any significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)