Vascular ring (aorta)

A vascular ring is a developmental anomaly of the aortic arch. It occurs in about 0.3% of the population.

Failure of disappearance or development of one or more of the aortic arches results in constriction of the oesophagus and trachea between aberrant vessels.

It may be produced by:

• an accessory aorta running anterior to the oesophagus and trachea with the 'normal aorta' running posteriorly. Often, the accessory aorta is the site of origin of the left common carotid and subclavian arteries.
• the right common carotid artery arising directly from the arch of the aorta as its most proximal branch. The right subclavian artery arises from the arch distal to the left subclavian artery on the left side to pass posterior to the trachea and oesophagus across the posterior mediastinum. There is no brachiocephalic trunk.
• a right-sided aortic arch due to regression of the left fourth branchial arch artery and dorsal aorta

The condition may be silent clinically or present at birth or the first few months of life with stridor and dysphagia. Gradually, these symptoms worsen as their is relatively greater growth of the trachea and oesophagus than vessels. The first anomaly - a double aorta - is more likely to produce symptoms than the abnormal origin of the right subclavian artery.

Diagnosis is by barium swallow.

Treatment is by surgical division of the ring.