Yoshio Kanzaki

Postoperative Size of the Right Ventricular Outflow Tract and Optimal Age in Complete Repair of Tetralogy of Fallot

Abstract One hundred forty-three patients underwent complete repair of tetralogy of Fallot with an overall mortality of 14.7%. The mortality rate correlated with the preoperative pulmonary artery to aorta (PA/Ao) diameter ratio but not with age. A retrospective study revealed that for success, the postoperative pulmonary annulus should be over 1.75 cm 2 per square meter of body surface area (BSA) in patients with a BSA of less than 0.6 m 2 at operation. The younger the patient, the lower was the ratio of right ventricular to aortic systolic pressure, even when the cross-sectional area index (CSAI) of the pulmonary annulus was the same. Even with application of an outflow patch, pulmonary regurgitation was negligible when the CSAI was less than 2.6 cm 2 /m 2 . The pulmonary vascular response to increased blood flow was excellent in younger patients. Residual ventricular septal defect and recurrent pulmonary stenosis were unrelated to age. Thus, for symptomatic patients, even infants, we recommend that complete repair be attempted when the PA/Ao diameter ratio is over 0.3. For patients in whom this ratio is less than 0.3, operation should be undertaken when the average diameter index of the arterial pathway to the right upper lobe is above 4 mm/m 2 . Should this index be less than 4 mm/m 2 , a two-stage operation is recommended.