Purpose or Case Report: Major aortopulmonary collateral arteries (MAPCAs) are congenital vessels derived from the splanchnic vascular plexus connecting the systemic circulation to the pulmonary arterial vasculature. These abnormal collateral vessels persist after birth when there is disruption of normal antegrade flow through the pulmonary arteries. MAPCAs are most commonly seen in patients with Tetralogy of Fallot with pulmonary atresia (TOF/PA).
Our patient was prenatally diagnosed with hypoplastic left heart syndrome (HLH) and anomalous pulmonary venous return. She was born at term with an initial CT angiogram showing obstructive supracardiac total anomalous pulmonary venous return (TAPVR) and a small sub-millimeter MAPCA. The patient underwent immediate vertical vein stenting and subsequently underwent Norwood and open TAPVR repair on day of life 16. She continued to clinically deteriorate due to elevated pulmonary arterial pressures and was eventually diagnosed with occlusion of her left pulmonary veins, confirmed on repeat CT angiography where the small MAPCA had increased to over 2 mm in size. The patient continued to experience pulmonary hypertension resulting in respiratory failure requiring intubation and eventual extracorporeal membranous oxygenation. She became hypoxic and bradycardic during operative tracheostomy placement and was unable to be resuscitated.
Methods & Materials:
Results:
Conclusions: MAPCAs are uncommon findings often associated with pulmonary arterial insufficiency. This case presents a unique combination of congenital anatomic anomalies leading to compromised pulmonary arterial supply. Most MAPCAs are present at birth and evaluated for eventual unifocalization procedure. Growth of a MAPCA is extremely rare and is reflective of continued deficient pulmonary arterial blood flow. Pediatric radiologists should be (1) aware of MAPCAs on CTA when treating congenital heart patients, (2) understand other contexts beyond Tetralogy where MAPCAs can occur, and (3) appreciate the clinical implications of continued collateral blood supply recruitment by the lung following delivery.