Prenatal ultrasonic diagnosis and analysis of right aortic arch

LIANGXiangkong; CHENLanfang; LIANGFengpei; CHENQiuyan

Abstract：ObjectiveTo investigate the diagnostic value of typical ultrasound sonographic features of the right aortic arch (RAA) in the fetus andto improve the accuracy of prenatal diagnosis.MethodsEchocardiographic characteristics of thefetal RAA cases diagnosed and confirmed in our hospital from 2014 to 2018 were retrospectively analyzed.ResultsIn 78 consecutive fetuses with a diagnosis of RAA, 37 patients were diagnosed after birth by echocardiography or CT, including 24 cases of RAA with aberrant left subclavian artery (RAA - ALSA) and 10 cases of RAA with mirror image branching pattern (RAA‐MI). Fetal " U-shaped”appearance was found in 29/37 patients (82%) and all had a complete vascular ring, included 24 patients (82.4%) had RAA with left posterior ductus arteriosus (LPDA) and aberrant left subclavian artery (ALSA) (RAA/LPDA/ALSA), 3 patients (10.3%) with double aortic arch (DAA), 2 patients (6.9%) RAA with LPDA and mirror image branching (RAA/LPDA/MI). Fetal " V-shaped” appearance was found in 8 patients (5.4%) and all had RAA with right DA (RDA) not forming vascular rings. In addition, 6/37 (16.2%) fetuses didn’t have a " U-shaped” or " V-shaped” structure, found with left anterior ductusarteriosus and mirror image branching branching andwithout forming vascular rings. RAA was related with intracardiac structural abnormalities. There were 12 patients with a congenitalheart defectin, which " RAA forming vascular rings”was related with simple congenital heart diseases in 4/29 (13.8%). " RAA not forming vascular rings” was related with complex congenital heart diseases in 8/12 (66.7%).Conclusion" V-shaped” appearance only means that the transverse section of the aortic arch and the arterial catheter run together on the same side of the thorax, while " U-shaped” appearance is the sign of a vascular ring. RAA forming vascular ring or not is closely related to congenital heart diseases and provides guidance for prenatal diagnosis and prognosis of the right aortic arch.