Combination of echocardiographic views better diagnoses and differentiates fetal right aortic arch and double aortic arch: experience from multi-center study

Abstract Purpose Patients with fetal right aortic arch (RAA) and double aortic arch (DAA) have different clinical outcomes, while fetal screening by traditional echocardiography provides limited information. This study aimed to discover and evaluate a novel combination of different echocardiography views in the diagnosis and differentiation of RAA and DAA. Methods From January 2014 to December 2022, the cases diagnosed as RAA or DAA by initial ultrasound screening from two hospitals were divided into the RAA group and DAA group. All the pregnant women were routinely offered karyotyping if confirmed diagnosis. Three-vessel-trachea (3VT) and descending aortic arch (DAO) coronal views were combined for further diagnosis, and the reasons for misdiagnosis were analyzed and summarized. Results A total of 332 cases were diagnosed with RAA or DAA by initial ultrasound, including RAA group 244 cases and DAA group 88 cases. In the RAA group, the mirror RAA (MRAA) could not be completely diagnosed by 3VT view alone, with the accuracy and sensitivity of 88.9% and 72.6%, respectively. In the DAA group, 36 cases were misdiagnosed only by 3VT view alone, with the accuracy and specificity of 88.9% and 86.8%, respectively. However, the accuracy for MRAA or DAA could reach to 100% when combining with 3VT and DAO coronal views. The abnormal detection rate of karyotyping was 10.5% (20/190), excluding the cases who refused the karyotyping. Conclusion Combining 3VT and DAO coronal view could effectively distinguish RAA variants from DAA. The karyotyping should be recommended for the patients with RAA or DAA, and the accurate prenatal diagnosis was highly valuable to provide appropriate perinatal counseling and prognostic evaluation.