[Double aortic arch: prenatal case report].

We have presented a case of prenatal double aortic arch, diagnosed by ultrasound, to demonstrate the importance of 3-vessel view by detecting aortic arch abnormalities. Double aortic arch is one the most common types of the vascular ring. The suspicion of a double aortic arch is raised by detecting the U-sign which is formed by the combination of both aortic arches and the left ductus arteriosus. In the 3-vessel view the ascending aorta and aortic arch are pointing to the right, whereas the left arch points to the left, and the trachea is seen between. The 4-chamber view appears normal, but the descending aorta is deviated medially. Literature review revealed an association between double aortic arch and congenital heart diseases in approximately 20% of cases; most often tetralogy of Fallot, transposition of great vessels, ventricular septal defects. Rarely there can be atresia of the segment of the aortic arch, which can be difficult to differentiate from other aortic arch anomalies associated with chromosomal abnormalities such as microdeletion of chromosome 22q11.