Ninety consecutive corrective operations for tetralogy of Fallot with or without minimal right ventriculotomy.

Eighty-eight patients with tetralogy of Fallot and two patients with ventricular septal defect and pulmonary atresia underwent repair without right ventriculotomy (n = 43) or with a minimal right ventriculotomy (n = 47) of 10 to 15 mm. The ventricular septal defect was closed through the tricuspid valve in 75 patients. The pulmonary valve was either preserved or reconstructed to maintain its competence. The age at operation was 1 or 2 years in 51 patients. There was one operative death and there were no late deaths. The results of postoperative cardiac catheterization in the present series of patients (n = 34) were compared with those of control patients (n = 21) who had repairs with a conventional right ventriculotomy in the preceding period. There was no significant difference in right ventricular/left ventricular systolic pressure ratio or in cardiac index either at rest or during isoproterenol infusion between the two groups. The incidence of significant pulmonary regurgitation (Grade greater than or equal to 2/4) was less (p less than 0.05) in the present patients (47%, n = 34) than in the control patients (81%, n = 21). The right ventricular end-diastolic volume index (ml/m2) was smaller in the present patients than in the control patients both at rest (91 +/- 37 versus 142 +/- 28, p less than 0.01) and during isoproterenol infusion (81 +/- 21 versus 109 +/- 30, p less than 0.01). The right ventricular ejection fraction was higher in the present patients than in the control patients during isoproterenol infusion (57% +/- 4% versus 49% +/- 6%, p less than 0.01). The incidence of ventricular arrhythmias (Lown's grade greater than or equal to 2) was less in the present patients (6/35) than in the control patients (36/65) (p less than 0.005). This method of repair for tetralogy of Fallot carries no more risk than the conventional method, and the results are better with respect to postoperative right ventricular function and ventricular arrhythmia.