Aberrant right subclavian artery is a rare vascular anomaly, but it is a relatively frequent form of congenital vascular anomalies. It happens when there is abnormal origin of subclavian artery from the arch of the aorta. It usually arises caudal to the origin of the left subclavian and then courses across to the right side usually dorsal to the esophagus and emerges from the thorax over the first right rib.

Usually it remains clinically silent, but patients may present with unexplained dysphagia or chronic intermittent cough.

Symptomatic forms are most often seen as a retro-esophageal aberrant subclavian artery arising from a dilated segment of the aorta (diverticulum of Kommerell).

Diagnosis is usually achieved with a barium filled esophagus which demonstrates oblique indentation in the posterior esophageal wall at the level of aortic arch. Definitive diagnosis is now usually accomplished by CT or MRI.

Differentials on fluoroscopy:

1. Double aortic arch or other vascular anomaly.
2. Tumors in the wall or lumen of the esophagus.
3. Mediastinal tumors or adenopathy.