The significance of a prenatal diagnosis of right aortic arch.

OBJECTIVES

To analyze a population of fetuses with prenatally diagnosed right aortic arch (RAA).

METHODS

Retrospective study of fetuses with RAA diagnosed prenatally between 2011 and 2015 in two referral centers.

RESULTS

Right aortic arch was found in 4.4% (46/1036) of fetuses with cardiovascular abnormalities (CVA). As an isolated anomaly, RAA was present in 30.4% of cases; in 32.6%, other CVA were detected; in 23.9%, CVA and extracardiac anomalies; and in 13.1%, only extracardiac malformations. The most common noncardiac abnormalities were thymus hypoplasia/aplasia (7/17), of which six had deletion 22q.11.2. In another three fetuses, trisomy 21 was present. One intrauterine fetal death occurred at 41 weeks of pregnancy, and two fetuses died after birth. In six of 18 infants with known follow-up, symptoms of dysphagia were reported, of which four infants underwent surgical intervention. In 12 infants, an isolated RAA was clinically silent.

CONCLUSIONS

The diagnosis of RAA is an indication for a detailed examination of cardiac and noncardiac structures, including the thymus. It is advisable to consider genetic testing, together with the assessment of deletion 22q11.2, especially in the case of accompanying defects. The prognosis depends on underlying cardiac and extracardiac anomalies and possibly coexisting genetic defects. Isolated anomalies are asymptomatic. © 2017 John Wiley & Sons, Ltd.