A Rare Case of Posterior Malalignment VSD with Interrupted Right Arch and Isolated Left Common Carotid Artery

We present a rare and yet unreported constellation of cardiovascular anomalies in a girl with DiGeorge Syndrome (DGS) and congenital athymia due to 22q11.2 deletion and describe her clinical course leading to corrective surgery. Cardiac findings included a large posterior malalignment ventricular septal defect (VSD), a severely hypoplastic aortic valve, and a proximal ascending aorta that continued as the right common carotid artery (RCCA). The aortic arch was right-sided and interrupted. From the main pulmonary artery (MPA), a right-sided patent ductus arteriosus (right PDA) continued as a right-sided descending aorta, which gave rise to the right subclavian artery (RSCA) and an aberrant left subclavian artery (LSCA). A left-sided PDA continued as the isolated left common carotid artery (LCCA). Only 18 cases of Isolated LCCA have been previously reported, none of which were associated with an interrupted right aortic arch. In this case, palliative cardiac catheterization was followed by corrective cardiac surgery and later successful thymic transplantation.