Aberrant right subclavian artery

Aberrant right subclavian arteries (ARSA), also known as arteria lusoria, are the commonest of the aortic arch anomalies 2


The estimated incidence is 0.5-2%.

Clinical presentation

They are often asymptomatic, but around 10% of people may complain of tracheo-oesophageal symptoms, almost always as dysphagia termed dysphagia lusoria 3



Instead of being the first branch (with the right common carotid as the brachiocephalic artery), it arises on its own as the fourth branch, after the left subclavian artery. It then hooks back to reach the right side. Its relationship to the oesophagus is variable:

  • 80% posterior to oesophagus
  • 15% between oesophagus and trachea
  • 5% anterior to the trachea
  • as can be expected from embryology, the right recurrent laryngeal nerve is usually non-recurrent (that is, enters the larynx directly)
  • aneurysmal dilatation (aberrant subclavian arterial aneurysms) of the proximal portion of an aberrant right subclavian artery can occur, a pouch like aneurysmal dilatation is called a diverticulum of Kommerell
  • if there is a retro-oesophageal course:
    • it can get compressed between the oesophagus and the vertebra
    • the incidence of stenosis/occlusion in this segment is higher
  • it can be associated with trisomy 21, trisomy 18 and other chromosomal defects.

Radiographic features


An upper GI contrast study will demonstrate displacement of the contrast-filled oesophagus. This displacement by the aberrant vessels produces the so-called bayonet deformity of aberrant right subclavian artery.

Related articles

Thoracic anatomy

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