Giant aorto-pulmonary collaterals in pulmonary atresia and ventricular septal defect: long-term survival in unoperated adults.

The association of pulmonary atresia and ventricular septal defect (PA/VSD) can be considered the most severe form of tetralogy of Fallot. The main feature of this congenital heart disease is represented by discontinuity between the right ventricle and pulmonary trunk or its branches; the anatomy of central pulmonary arteries is often abnormal, consequently the type and the amount of sources of pulmonary blood flow are variable. Due to evolution in surgical techniques, definitive correction is now also considered in more complex cases. A small rate of unoperated patients with PA/VSD can survive until adulthood and the arterial blood supply to the lungs, provided by major aorto-pulmonary collateral arteries (MAPCAs), is one of the main determinants of survival. We report two unoperated cases of PA/VSD and MAPCAs with long-term survival. Giant MAPCAs can occasionally be found by chest radiography in adults with unrepaired PA/VSD. Moreover, non-invasive assessment of the pulmonary arterial bed with computer tomography or MRI is helpful in these patients during follow-up. Finally, we discuss the use of oral anticoagulants and/or 5-phosphodiesterase inhibitors in these patients.