EURORAD ESR

Case 826

Right aortic arch with aberrant left subclavian artery

Author(s)
H. Aniq, JA. Holemans
 
Patient
male, 46 year(s)

Clinical History

A fit non-smoker with a family history of lung cancer. A chest radiograph suggested a widened superior mediastinum.

Imaging Findings

A teacher and ex-paratrooper returned from a high altitude trekking holiday in Nepal complaining of weight loss. He was non-smoker but there was a family history of lung cancer. Physical examination was unremarkeble. A chest radiograph showed a widened superior mediastinum. Bronchoscopy was normal. A contrast enhanced spiral CT was performed with surface shaded 3D vascular reconstruction.

Discussion

A right sided aortic arch occurs in 1-2%. Right aortic arch with aberrant left subclavian artery is the commonest right aortic arch anomaly(35-72%). Right aortic arch with aberrant left subclavian artery has an incidence of 1:2500. It is associated with congenital heart disease in 5-10% of cases. This is the second most common cause of vascular ring after double aortic arch. Patients with this anomaly are usually asymptomatic as the ring around the oesophagus and trachea is loose. However it may present in infancy/childhood and very rarely in adults due to a tight vascular ring compressing the trachea or oesophagus. In adults this condition can be misinterpreted as a mediastinal mass because of widened mediastinum on chest radiograph. In this anomaly the left common carotid artery is the first branch of the ascending aorta followed by right common carotid and right subclavian artery. The left subclavian artery is the fourth branch arising from the proximal descending aorta via a remnant of the embryological left dorsal aortic root. Often there is a bulbous origin, the diverticulum of Kommerell. The left ductus arteriosus also arises from this diverticulum and extends to the left pulmonary artery completing the vascular ring. Extrinsic compression of the posterior oesophagus is caused by either the aberrant left subclavian artery, which takes an oblique course from right to left, or the posterior aspect of the aortic arch itself. There may be indentation of oesophagus or trachea on right side due to right aortic arch.

Final Diagnosis

Rt. aortic arch with aberrant lt. subclavian art.
 

MeSH

  1. Aorta, Thoracic [A07.231.114.056.372]
    The portion of the descending aorta proceeding from the arch of the aorta and extending to the diaphragm.
  2. Subclavian Artery [A07.231.114.839]
    Artery arising from the brachiocephalic trunk on the right side and from the arch of the aorta on the left side. It distributes to the neck, thoracic wall, spinal cord, brain, meninges, and upper limb.

References

  1. [1]
    Naidich DP, Webb RW, Muller NL, Krinsky GA, Zerhouni EA, Siegelman SS. Computed tomography and magnetic resonance of the thorax. Lippincott-Raven, Philadelphia (1999).

Citation

H. Aniq, JA. Holemans (2001, May 25).
Right aortic arch with aberrant left subclavian artery, {Online}.
URL: http://www.eurorad.org/case.php?id=826
To top
 
  • Published 25.05.2001
  • DOI 10.1594/EURORAD/CASE.826
  • Section Cardiovascular
  • Case-Type Anatomy
  • Difficulty Resident
  • Views 594
  • Language(s)
  • Figure 1
    PA chest radiograph

    Smooth widening of the superior mediastinum

     
  • Figure 2
    Axial contrast enhanced thoracic CT
    a b c d e f  

    Four aortic arch branches are visible, two on the right and two on the left.

    The right and left common carotid arteries lie anterior to the right and left subclavian arteries respectively.

    Note the left common carotid artery anterior to the trachea.

    The left common carotid artery remains anterior to the trachea and the left subclavian is passing behind the oesophagus.

    The aortic arch is right sided and the left common carotid passes anterior to the trachea from the right side.

    The left common carotid origin is from the right sided arch. The origin of the left subclavian is from the descending aorta and is bulbous (diverticulum of Kommerell).

     
  • Figure 3
    PA Surface shaded 3D CT angiogram

    There is a rignt sided aortic arch. There are four arch branches. The first branch swings from the right to the left neck (left common carotid). The origin of the last branch (left subclavian) is aberrant.

     
Figure 1

PA chest radiograph

Smooth widening of the superior mediastinum
 
Figure 2

Axial contrast enhanced thoracic CT

Figure 2a
Four aortic arch branches are visible, two on the right and two on the left.
 
Figure 2b
The right and left common carotid arteries lie anterior to the right and left subclavian arteries respectively.
 
Figure 2c
Note the left common carotid artery anterior to the trachea.
 
Figure 2d
The left common carotid artery remains anterior to the trachea and the left subclavian is passing behind the oesophagus.
 
Figure 2e
The aortic arch is right sided and the left common carotid passes anterior to the trachea from the right side.
 
Figure 2f
The left common carotid origin is from the right sided arch. The origin of the left subclavian is from the descending aorta and is bulbous (diverticulum of Kommerell).
 
Figure 3

PA Surface shaded 3D CT angiogram

There is a rignt sided aortic arch. There are four arch branches. The first branch swings from the right to the left neck (left common carotid). The origin of the last branch (left subclavian) is aberrant.
 
To top
 
Home Search History FAQ Contact Disclaimer Imprint