Diverticulum of kommerell

Enlargement of the proximal portion of an aberrant proximal right subclavian artery at its site of origin from the descending aorta. Frequently, the term is also used to refer to the focal aortic enlargement near or at the site of origin of an aberrant left subclavian aorta just beyond a right aortic arch. This latter enlargement is properly called aortic diverticulum. The left-sided enlargement infrequently causes airway or oesophageal compression. The presence and size of the diverticulum can be demonstrated on barium swallow oesophagography and clearly depicted by thoracic aortography, CT and MRI. The latter two modalities also show the severity of airway compression.