Aberrant Right Subclavian Artery and Dysphagia Lusoria-CT

The most common congenital anomaly of the aortic arch is a left aortic arch with an aberrant right subclavian artery. This abnormal origin of the right subclavian artery can be explained by the involution of the 4th vascular arch with the right dorsal aorta.3 The 7th intersegmental artery remains attached to the descending aorta, and this persistent intersegmental artery becomes the right subclavian artery. This leads to the aberrant artery, which often follows a retro-esophageal course. Note the aberrant right subclavian arising from the left sided aortic arch and showing retro-esophageal course, and will show posterior indentation on barium swallow.