Utility of the Angle between the Right Aortic Arch and First Branch for Detecting Double Aortic Arch via Fetal Echocardiography.

INTRODUCTION: The presence of a double aortic arch (DAA) is manifested by compressive symptoms, requiring surgery. DAA cases are classified as either complete or incomplete type. DAA and a right aortic arch with mirror image branching (mRAA) have a similar configuration to the first branch artery. The first branch of the mRAA is the left brachiocephalic artery, which appears to be the same as that of an incomplete DAA due to blood flow interruption. The present retrospective study aimed to evaluate the differences between DAA and mRAA by fetal echocardiography. METHODS: This single retrospective cohort study included all patients diagnosed with complete DAA, incomplete DAA, or mRAA at our facility between 2010 and 2022. The patients were diagnosed with complete DAA, incomplete DAA, or mRAA after birth and remaining fetal echocardiograms. The patients were divided into the DAA (complete DAA: n = 4, incomplete DAA: n = 3) and mRAA (n = 4) groups. The following three outcomes were compared: (1) angle between the right aortic arch and first branch (RF angle), (2) ratio of height to width of the region bounded by the aortic arch, first branch of the aortic arch, and descending aorta, and (3) maximum tracheal diameter on a three-vessel trachea view. RESULTS: The incomplete DAA cases were difficult to diagnose via fetal echocardiography. On fetal echocardiography, the RF angle was significantly steeper in the DAA group than in the mRAA group (median 57° [36°-69°] vs. 75° [62°-94°]; p < 0.05). The DAA and RAA groups showed no significant differences in the ratio of height to width of the region bounded by the aortic arch, first branch of the aortic arch, and descending aorta (median 0.57 [0.17-0.68] vs. 0.73 [0.56-1.0]) and maximum tracheal diameter (median 2.5 [1.4-3.3] vs. 3.2 [2.8-3.5] mm). The cut-off value for the presence of DAA was an RF angle <71°. CONCLUSION: The DAA group (complete and incomplete DAA) had a significantly steeper RF angle than the mRAA group. Therefore, RF angle measurement could improve the fetal diagnosis and postnatal prognosis of DAA.

Utility of novel echocardiographic measurements to improve prenatal diagnosis of coarctation of the aorta.

Prenatal recognition of coarctation of the aorta (CoA) may improve neonatal survival and reduce morbidity. However, prenatal diagnosis of CoA remains challenging, with relatively high false-positive and false-negative rates. This study aimed to identify a novel formula based on fetal echocardiographic measures to predict prenatal identification of CoA. A retrospective comparison on the echocardiographic evaluation of 30 patients with suspected CoA between May 2016 and April 2021 was performed. The patients were divided into a postnatal surgical intervention group (n = 13) and a non-intervention group (n = 17). The measurements that showed significant differences were aortic isthmus diameter Z-score (p < 0.001), ductus arteriosus diameter/aortic isthmus diameter (p < 0.001), and distal aortic arch (DA) index (p < 0.001). In the receiver operating characteristic curves analysis, the DA index was the largest with an area under the curve of 0.941 and a cutoff value of 1.28, with a sensitivity of 85% and a specificity of 94%. Measurement of the DA index improved the diagnostic rate of fetal CoA and a DA index ≧ 1.28 indicated fetal CoA cases requiring surgical intervention.