Abstract

Abnormal right subclavian artery (ARSA) is the most common anomaly of the aortic arch with a rate of 0.5-1.4%. Normally, three vessels arises from the aortic arch, while four vessels arise in ARSA. ARSA leaves the distal of the aortic arch and passes behind the esophagus and trachea. It is also called the abnormal retroesophageal right subclavian artery.

It is generally an asymptomatic benign finding, but it can cause esophageal compression causing dysphagia.

In this article, an isolated ARSA and trisomy 21 case referred to our clinic in the second trimester of pregnancy and detected ultrasonographically is presented.