Aberrant right subclavian artery: A multi-detector computed tomography study

Introduction: Aberrant right subclavian artery (ARSA) arises as the last branch of normally positioned aortic arch and its prevalence estimated as 0.16%–2.0% varies between different ethnic groups. Our aim was to assess the prevalence and associated branching anomalies of ARSA in the Indian participants. Material and Methods: Chest computed tomographic scans of 710 patients were analyzed to study the ARSA and its associated vascular anomalies. Results: We have observed 11 cases (5 in males and 6 in females) of ARSA with an estimated prevalence of 1.54%. In seven cases, there were four branches arising from the arch of aorta in the order of right common carotid, left common carotid, left subclavian, and aberrant right subclavian. In three cases, there were three branches – bicarotid trunk (common trunk of right and left carotids), left subclavian, and the aberrant right subclavian. In one case, there were five branches in the order of right common carotid, left common carotid, left vertebral, left subclavian, and aberrant right subclavian. Only two participants reported mild symptoms of dysphagia. In all the cases, the ARSA had retroesophageal course. Kommerell diverticulum was not observed. ARSA remain asymptomatic in most cases, but its presence should alert the clinician to look for associated vascular and any cardiac anomalies. Discussion and Conclusion: Awareness of the presence of ARSA is crucial for successful outcome of mediastinal, esophageal, and thoracic spine surgeries. Preprocedural computed tomography for the evaluation of aortic arch branching pattern will be beneficial for the successful performance of various surgical and radiological interventions.