Tetrology of Fallot (TOF) comprises 3.9% of congenital heart disease,[1] of which approximately 5–10% have pulmonary atresia (PA) with ventricular septal defect (VSD). Two-thirds of the cases with PA are associated with major aorto pulmonary collateral arteries (MAPCAs). Survival rate without surgery can be as low as 50% at 1 year of age and 8% at 10 years.TOF, PA with MAPCAs is a complex congenital cardiac anomaly and one of the most challenging groups to manage surgically.

Reference: Annals of Pediatric Cardiology

M. Srikanth,Singh J, Kalyanpur A. Helical Ct Evaluation Of Pulmonary Arteries And Aortopulmonary Collaterals In Pulmonary Atresia. Annals of Pediatric Cardiology. 2009 April