Aberrant right subclavian artery

Changed by Henry Knipe, 6 Sep 2022
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Aberrant right subclavian arteries (ARSA), also known as arteria lusoria, are among the commonest aortic arch anomalies

Epidemiology

The estimated incidence is 0.5-2% 1.

Clinical presentation

They are often asymptomatic, but around 10~10% of people may complain of tracheo-oesophageal symptoms, almost always as dysphagia, termed dysphagia lusoria 2.

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 3:

  • 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, entering 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 4, trisomy 18 and other chromosomal defects.ref

Radiographic features

Plain radiograph

Lateral radiographs of the chest may show obliteration of the retrotracheal space.

Fluoroscopy

An upper GI contrast study will demonstrate displacement of the contrast-filled oesophagus 5. This displacement by the aberrant vessels produces the so-called bayonet deformity of the 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 5.

Complications

The presence of an 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 important in thyroid and parathyroid surgeries 6.

  • -<p><strong>Aberrant right subclavian arteries</strong> <strong>(ARSA)</strong>, also known as <strong>arteria lusoria</strong>, are among the commonest <a href="/articles/variant-anatomy-of-the-aortic-arch">aortic arch anomalies</a>. </p><h4>Epidemiology</h4><p>The estimated incidence is 0.5-2% <sup>1</sup>.</p><h4>Clinical presentation</h4><p>They are often asymptomatic, but around 10% of people may complain of tracheo-oesophageal symptoms, almost always as dysphagia, termed <a href="/articles/dysphagia-lusoria">dysphagia lusoria</a><sup> 2</sup>.</p><h4>Pathology</h4><h5>Course</h5><p>Instead of being the first branch (with the <a href="/articles/common-carotid-artery-2">right common carotid</a> as the <a href="/articles/brachiocephalic-trunk">brachiocephalic artery</a>), it arises on its own as the fourth branch, distal to the <a href="/articles/subclavian-artery">left subclavian artery</a>. It then hooks back to reach the right side with its relationship to the <a href="/articles/oesophagus">oesophagus</a> variable <sup>3</sup>:</p><ul>
  • +<p><strong>Aberrant right subclavian arteries</strong> <strong>(ARSA)</strong>, also known as <strong>arteria lusoria</strong>, are among the commonest <a href="/articles/variant-anatomy-of-the-aortic-arch">aortic arch anomalies</a>. </p><h4>Epidemiology</h4><p>The estimated incidence is 0.5-2% <sup>1</sup>.</p><h4>Clinical presentation</h4><p>They are often asymptomatic, but ~10% of people may complain of tracheo-oesophageal symptoms, almost always as dysphagia, termed <a href="/articles/dysphagia-lusoria">dysphagia lusoria</a><sup> 2</sup>.</p><h4>Pathology</h4><h5>Course</h5><p>Instead of being the first branch (with the <a href="/articles/common-carotid-artery-2">right common carotid</a> as the <a href="/articles/brachiocephalic-trunk">brachiocephalic artery</a>), it arises on its own as the fourth branch, distal to the <a href="/articles/subclavian-artery">left subclavian artery</a>. It then hooks back to reach the right side with its relationship to the <a href="/articles/oesophagus">oesophagus</a> variable <sup>3</sup>:</p><ul>
  • -<li>as can be expected from the embryological development of the artery, the right <a href="/articles/recurrent-laryngeal-nerve">recurrent laryngeal nerve</a> is usually <a href="/articles/non-recurrent-laryngeal-nerve">non-recurrent</a>, entering the larynx directly. </li>
  • -<li>aneurysmal dilatation (<a href="/articles/aberrant-subclavian-arterial-aneurysms">aberrant subclavian arterial aneurysms</a>) of the proximal portion of an aberrant right subclavian artery can occur, a pouch-like aneurysmal dilatation is called a <a href="/articles/kommerell-diverticulum">diverticulum of Kommerell</a>.</li>
  • +<li>as can be expected from the embryological development of the artery, the right <a href="/articles/recurrent-laryngeal-nerve">recurrent laryngeal nerve</a> is usually <a href="/articles/non-recurrent-laryngeal-nerve">non-recurrent</a>, entering the larynx directly.</li>
  • +<li>aneurysmal dilatation (<a href="/articles/aberrant-subclavian-arterial-aneurysms">aberrant subclavian arterial aneurysms</a>) of the proximal portion of an aberrant right subclavian artery can occur, a pouch-like aneurysmal dilatation is called a <a href="/articles/kommerell-diverticulum">diverticulum of Kommerell</a>
  • +</li>
  • -<li>it can be associated with <a href="/articles/down-syndrome">trisomy 21</a> <sup>4</sup>, <a href="/articles/edwards-syndrome-1">trisomy 18</a> and other chromosomal defects.</li>
  • +<li>
  • +<a href="/articles/down-syndrome">trisomy 21</a> <sup>4</sup>, <a href="/articles/edwards-syndrome-1">trisomy 18</a> and other chromosomal defects <sup>ref</sup>
  • +</li>

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