Aberrant right subclavian artery
Updates to Article Attributes
Aberrant right subclavian arteries (ARSA), also known as arteria lusoria, are one of the commonest of the aortic arch anomalies.
Epidemiology
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.
Pathology
Course
Instead of being the first branch (with the right common carotid as the brachiocephalic artery), it arises on its own as the fourth branch, distal to the left subclavian artery. It then hooks back to reach the right side with its relationship to the oesophagus variable:
- 80% posterior to the oesophagus
- 15% between oesophagus and trachea
- 5% anterior to the trachea
Associations
- as can be expected from the embryological development of the artery, 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 5, trisomy 18 and other chromosomal defects.
It is associated with PHACE syndrome
Radiographic features
Fluoroscopy
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.
CT/MRI
CT and MRI both demonstrate the aberrant branch arising from the distal left aortic arch and coursing rightwards, and can define the relationship between the aberrant artery and the trachea and oesophagus.
Complications
The presence of aberrant right subclavian artery poses a substantial risk of life-threatening haemorrhage in patients undergoing surgery like oesophagectomy. Moreover, the recurrent laryngeal nerve does not follow the orthodox course which is of importance in thyroid and parathyroid surgeries 6.
-<li>it can be associated with <a href="/articles/down-syndrome">trisomy 21</a> <sup>5</sup>, <a href="/articles/edwards-syndrome-1">trisomy 18</a> and other chromosomal defects. It is associated with PHACE syndrome</li>- +<li>it can be associated with <a href="/articles/down-syndrome">trisomy 21</a> <sup>5</sup>, <a href="/articles/edwards-syndrome-1">trisomy 18</a> and other chromosomal defects.</li>
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