This patient is known for D-TGA and right ventricular hypoplasia, who underwent arterial switch and right sided unidirectional Glenn procedure (SVC to right pulmonary artery anastamosis).  He later developed stenosis of the right pulmonary artery, requiring surgical reconstruction with Glenn take down. Multiple (right-sided) major aortopulmonary collateral arteries (MAPCAs) developed as a result of the right-sided pulmonary artery stenosis.