Aortic arch with four vessels: aberrant right subclavian artery

Abstract

In early gestation, the aortic arch undergoes complex development1 that normally results in the formation of a left aortic arch from which three arteries originate: 1) the brachiocephalic artery, bifurcating into the right common carotid and right subclavian arteries, 2) the left common carotid artery and 3) the left subclavian artery (Figure 1). Development of the aortic arch is abnormal in approximately 1–2% of human fetuses, and may involve complex cardiac defects (e.g. interruption or tubular hypoplasia of the aortic arch, aortic coarctation