Left-sided esophageal indentation in right aortic arch with aberrant left subclavian artery

PURPOSE: To determine the structures responsible for the left-sided indentation in right aortic arch (RAA) with aberrant left subclavian artery (ALSA). MATERIALS AND METHODS: Magnetic resonance (MR) imaging was performed in five patients with RAA with ALSA in whom barium esophagography demonstrated a left-sided defect at the level of the aortic arch. RESULTS: In four patients, the aortic diverticulum (dorsal aortic root remnant) extended to the left of the esophagus, explaining the left-sided indentation. In one of those four patients, the ALSA contributed to this defect. In only one patient was no patent vascular structure identified to the left of the esophagus, and it was assumed that the ligamentum arteriosum alone produced this defect. CONCLUSION: The aortic diverticulum appears to be an important factor in the production of the left-sided esophageal defect in patients with RAA with ALSA.