Fate of right ventricle to pulmonary artery conduits after complete repair of pulmonary atresia and major aortopulmonary collaterals.

BACKGROUND Surgical repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals (PA/VSD/MAPCAs) requires insertion of a conduit from the right ventricle to the reconstructed pulmonary arteries. Although there is extensive literature on conduit longevity for many forms of congenital heart defects, there is currently limited information for PA/VSD/MAPCAs. It is likely that conduits will have a different longevity in PA/VSD/MAPCAs because pulmonary artery pressures are higher after unifocalization than in other congenital heart defects. The purpose of this study was to evaluate the fate of right ventricle to pulmonary artery conduits after complete repair of PA/VSD/MAPCAs. METHODS This was a retrospective review of 103 infants who underwent complete repair of PA/VSD/MAPCAs with insertion of an aortic homograft conduit. The average age at complete repair was 5.1 ± 2.8 months, average conduit size was 13 ± 2 mm, and average conduit z score was a positive 1.6 ± 0.9. RESULTS Conduit z scores were linearly correlated with increasing homograft conduit size. The average longevity of small homografts (8 to 11 mm) was 15 ± 4 months, medium homografts (12 to 14 mm) was 39 ± 7 months, and large homografts (15 to 17 mm) was 50 ± 14 months. There was a negative correlation between increasing pulmonary artery pressure and conduit longevity. CONCLUSIONS Conduit z scores and conduit size worked synergistically to predict the longevity of right ventricle to pulmonary artery conduits after complete repair of PA/VSD/MAPCAs. Pulmonary artery pressure was an additional modifier of longevity. These data provide a framework for expectations of aortic homograft conduits used in the repair of PA/VSD/MAPCAs.