Abnormal origin of the right subclavian artery from the right pulmonary artery in a patient with D-transposition of the great vessels and left juxtaposition of the right atrial appendage: an unusual anatomical variant.

Isolation of the left subclavian artery (LSCA) or its anomalous origin from the pulmonary artery (PA) has been documented in several cases, especially in association with a right-sided aortic arch. Similar anomalies involving the right subclavian artery (RSCA) are less frequent. Anomalous origin of the RSCA from the PA in association with D-transposition of the great arteries (D-TGA) is exceedingly rare and only two cases have been reported so far. We present here, a case of aberrant origin of the RSCA from the right PA in a patient with D-TGA, in whom the diagnosis was rendered difficult due to the partial occlusion of the intervening ductus arteriosus (DA). We discuss the embryological basis of this anomaly and review its clinical and surgical implications.