Adamson GT, McElhinney DB, Zhang Y, et al. - Researchers sought to detail pulmonary artery (PA) and major aortopulmonary collateral artery (MAPCA) anatomy in a large group of infants, evaluate connections between anatomy and early surgical outcomes, and consider systems for classifying MAPCAs. From 2001 to 2019, all infants ( < 1 year of age) undergoing first cardiac surgery for tetralogy of Fallot/MAPCAs at Stanford University have been identified. The anatomy of MAPCA is highly variable and basically identical for each patient. While each pulmonary segment may be supplied with MAPCA, central PA, or both, all anatomic combinations are equally conducive to good repair. An important driver of outcome is the total cross‐sectional area of central PA and MAPCA material. A number of novel associations between anatomic features are elucidated, but the extreme variability of the pulmonary circulation makes a granular tetralogy of Fallot/MAPCA classification system impractical.