右位主动脉弓的产前超声诊断

Prenatal ultrasonic diagnosis and analysis of right aortic arch

目的探讨胎儿右位主动脉弓(RAA)的典型超声声像图表现的诊断价值,以提高其产前诊断的准确性。方法回顾性分析2014～2018年于4家医院诊断并在产后明确的RAA病例的声像图特征及其产后随访情况。结果 78例胎儿时期诊断为RAA的病例中,有37例在产后通过超声心动图检查或CT检查明确诊断,其中RAA合并迷走左锁骨下动脉(RAA-ALSA)24例,RAA合并镜像分支(RAA-MI)10例;在三血管-气管切面中出现"U"型结构的胎儿约占78.4%,其中RAA伴迷走左锁骨下动脉、左后位动脉导管(RAA/ALSA/LPDA)24例(82.4%),DAA 3例(10.3%),RAA伴镜像分支、左后位动脉导管(RAA/MI/LPDA)2例(6.9%)。出现"U"型结构的病例均伴有完全性血管环形成,而"V"形结构在37例胎儿中的显现率为5.4%,所有胎儿均未发现血管环形成。另外,有6例(16.2%)胎儿既不出现"U"型结构,也不出现"V"形结构,均为右位主动脉弓合并左前位动脉导管,且无血管环形成。此外,RAA与心内结构畸形具有一定相关性。12例合并心内畸形,其中不形成血管环的胎儿合并心内畸形率约66.7%,且多合并复杂心内畸形。形成血管环的右位主动脉弓合并心内畸形率约13.8%,主要与简单先天性心脏病相关。结论研究发现三血管-气管切面出现"V"形结构仅仅意味着主动脉弓横部和动脉导管指向胸部的同一侧,而出现"U"形结构则是血管环形成的标,血管环形成与否也与是否合并心内畸形关系密切,为右位主动脉弓的产前诊断和判断预后提供指导意见。

Objective To 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.Methods Echocardiographic characteristics of thefetal RAA cases diagnosed and confirmed in our hospital from 2014 to 2018 were retrospectively analyzed.Results In 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.