Prenatal diagnosis of isolation of aortic brachiocephalic artery.

Background: Isolated aortic brachiocephalic artery (IABA) is a rare congenital aortic arch anomaly. It is difficult to diagnose IABA prenatally and the prevalence in the prenatal population is unknown.

Purpose: To evaluate the echocardiographic characteristics and associations in fetuses with IABA.

Material And Methods: We retrospectively analyzed all cases of prenatal diagnosis of IABA from January 2012 to November 2020 and reviewed the follow-up results. Copy Number Variation Sequencing (CNV-Seq) was performed using the biological specimens of the of the fetuses and family members.

Results: Ten cases (10/45652, 0.022%) of IABA were identified in our center. The prevalence of the cases with isolated left subclavian artery (ILSCA) in the right aortic arch (RAA) population was 0.98% (6/613). The ILSCA was the most common isolated arch branch. All the isolated branches were on the opposite side of aortic arch in all the cases. The "ice stick" sign in the coronal section could be seen in most cases of IABA. Of the 10 cases, 8 (8/10, 80%) were associated with tetralogy of Fallot (TOF). Two cases of IABA were combined with 22q11.2 deletion syndrome.

Conclusion: IABA is a rare aortic anomaly. ILSCA was the most common isolated arch branch and TOF was the most common associated intra-cardiac anomaly. The "ice stick" sign in the coronal section could indicate a diagnosis of the IABA.