Aberrant Right Subclavian Artery

Aberrant Right Subclavian Artery (ARSA) in Plain CT Thorax

ARSA is the most common Aortic Arch anomaly. Here the Right Subclavian artery arises as the last branch of the Aortic Arch. Majority(~80%) of ARSAs course posterior to the esophagus. Less common is  ARSA passing between esophagus and trachea and least common is passing anterior to trachea.

Most of the patients are asymptomatic, but in ~10% this can result in the compression of esophagus, which is then called as 'dysphagia lusoria'. (ARSA is also called as 'arteria lusoria').