Fetal double aortic arch: prenatal sonographic and postnatal computed tomography angiography features, associated abnormalities and clinical outcomes

Fetal double aortic arch (DAA) malformation is a rare congenital heart disease with few reported cases in the literature. We aimed to investigate the characteristics of prenatal ultrasound and postnatal computed tomography angiography (CTA) of DAA and to describe the associated anomalies and clinical outcomes to improve prenatal diagnosis and assist in perinatal management.

The obstetric ultrasound imaging databases of seven tertiary referral centers were reviewed retrospectively to identify fetuses with a prenatal diagnosis of DAA between January 2013 and December 2018. Ultrasonographic findings, associated anomalies, genetic abnormalities, postnatal CTA images, and long-term postnatal outcomes were evaluated.

A total of 36 cases out of 40 prenatally diagnosed DAA fetuses were confirmed by postnatal diagnosis (fetal autopsy, CTA, and surgery). In this cohort of 36 confirmed cases, 24 (67%) were isolated anomalies, while 12 (33%) were associated with intracardiac or extracardiac anomalies, and 2 (6%) had a 22q11.2 chromosome deletion. Among nine cases of pregnancy termination with a fetal autopsy, 7 had other abnormalities. Among the remaining 27 live births, 16 (59%) were asymptomatic and 11 (41%) received surgical treatment due to tracheal or esophageal compression symptoms, all with satisfactory outcomes. Prenatal echocardiography showed that DAA was mainly characterized by a bifurcation of the ascending aorta into the right and left aortic arch and the formation of a complete O-shaped vascular ring around the trachea on the three-vessel tracheal view. A variant in the aortic arch branching pattern was found for the first time. The airway obstruction, branching pattern, and atretic arch of DAA were clearly shown by postnatal CTA.

Fetal DAA has unique features on prenatal echocardiography and postnatal CTA, and systematic prenatal examination and timely postnatal CTA evaluation are required. A certain proportion of intracardiac and extracardiac abnormalities are associated with DAA, but the probability of chromosome abnormalities is low, especially for isolated DAA.The clinical outcomes of isolated DAA are favorable, even if surgery is performed due to symptoms. Determining whether other malformations or chromosomal anomalies exist is crucial for prognosis evaluation and prenatal counseling.