Large aortopulmonary collateral artery exclusively supplying the lower lobe of left lung in an infant with common arterial trunk with aortic dominance with confluent pulmonary arteries

Introduction Common arterial trunk with aortic dominance has well-developed bilateral pulmonary arterial arborization without any essential major aortopulmonary collateral arteries (MAPCAs), whereas "solitary" arterial trunk is characterized by collateral arterial supply to all bronchopulmonary segments and absent pulmonary arteries. Case Report We report a term female neonate with common arterial trunk with aortic dominance with confluent pulmonary arteries with a large MAPCA as the sole blood supply to the lower lobe of the left lung. Results Initial diagnostic workup missed this MAPCA from the descending thoracic aorta. It was suspected during surgery due to massive left atrial return and confirmed by cardiac catheterization study in the early postoperative period and treated successfully by unifocalization. Discussion A large essential MAPCA supplying an entire lobe in the common arterial trunk with aortic dominance has not been described. It can present as heart failure and inability to wean off the ventilator in the early postoperative period following intracardiac repair. Conclusion This is a case hitherto undescribed and possibly falling outside the well-entrenched classifications of the common arterial trunk and a large MAPCA could be an addition to the list of lesion modifiers. Our experience with this case underlines the importance of a thorough and open-minded approach to the initial imaging assessment of even well-described conditions.