Unusual Vascular Ring in the Fetus.

We present the clinical course and echocardiographic and genetic findings of two fetuses with an unusual vascular ring, created by a left aortic arch with a right arterial duct and an aberrant right subclavian artery. One fetus was diagnosed with 22q11.2 microdeletion and the other became symptomatic in infancy. It is important to consider the position of the arterial ductal ligament in patients who present with tracheoesophageal compressive symptoms in the presence of a left aortic arch. These cases also highlight that a vascular ring formed from a left arch may have similar associations to a vascular ring formed by a right aortic arch.