Aberrant subclavian artery

Presentation

The condition is usually asymptomatic. In 80% of individuals the aberrant artery crosses behind the esophagus, which may create a vascular ring around the trachea and esophagus. Dysphagia due to an aberrant right subclavian artery is termed dysphagia lusoria, though this is rare.

Other possible symptoms include stridor, dyspnoea, chest pain, or fever. Compression of the recurrent laryngeal nerve can cause palsy, known as Ortner's syndrome. The aberrant artery often arises from a dilated segment of the proximal descending aorta called the Diverticulum of Kommerell, also referred to as a lusorian artery.

Pathophysiology

Normal embryological development involves regression of the right dorsal aorta caudal to the origin of the 7th intersegmental artery, which gives rise to the right subclavian artery. In an aberrant right subclavian artery, regression occurs instead between the 7th intersegmental artery and the right common carotid, so the right subclavian artery connects to the left dorsal aorta via the part of the right dorsal aorta that normally regresses. The origin then migrates until it lies just distal to the left subclavian artery.

Diagnosis

An aberrant subclavian artery is usually found by chance during imaging that looks at blood vessel structure. In infants, an echocardiogram might hint at the abnormal placement, but it cannot always show the aorta clearly.

CT angiography with contrast produces detailed 3D images, revealing the artery's path near the trachea and esophagus. MRI or MR angiography, often used in children to avoid radiation, also shows the vascular anatomy. If swallowing problems occur, a barium swallow test can detect esophageal compression from the artery.