主动脉弓异常的产前超声诊断线索和技巧

Clues and techniques of prenatal ultrasonographic diagnosis for fetal aortic arch anomalies

目的分析常见主动脉弓异常的产前超声图像特征，探讨其诊断线索和技巧，以提高主动脉弓异常的产前诊断率。方法选取产前超声检查诊断为主动脉弓异常者作为研究对象，回顾性分析主动脉弓横切面（三血管气管切面）、矢状切面（主动脉弓长轴切面）和冠状切面（主动脉弓降部冠状切面）的产前超声图像特征。结果产前超声检查诊断为主动脉弓异常并获得随访结果者81例，其中左位主动脉弓左位动脉导管伴迷走右锁骨下动脉15例，右位主动脉弓左位动脉导管伴迷走左锁骨下动脉22例，右位主动脉弓左位动脉导管伴主动脉弓镜像分支4例，右位主动脉弓右位动脉导管伴主动脉弓镜像分支2例，双主动脉弓11例，主动脉缩窄23例，主动脉弓中断4例。其中27例合并心内外结构畸形，13例合并染色体异常。主动脉弓大小异常（主动脉缩窄）的产前超声线索为三血管气管切面显示主动脉内径明显小于肺动脉内径，主动脉弓长轴切面有利于显示主动脉缩窄的部位和范围。主动脉弓连续性异常（主动脉弓中断）的产前超声线索为三血管气管切面及主动脉弓长轴切面显示主动脉弓与降主动脉连续性中断。主动脉弓各段组合方式异常的产前超声诊断线索为三血管气管切面显示主动脉弓分支位置、排列和走行的异常，且主动脉弓降部冠状切面显示相应主动脉弓分支的异常改变。结论主动脉弓异常的各种类型在产前具有各自的特征性声像图表现，有相应的诊断线索和技巧。主动脉弓三切面的联合应用在产前可以有效地诊断主动脉弓异常。

Objective To explore the ultrasonographic features, diagnostic clues and methods of fetal aortic arch anomalies, and to improve the diagnosis rate of prenatal ultrasonography for fetal aortic arch anomalies. Methods Fetuses with aortic arch anomalies diagnosed by prenatal ultrasound were selected as the study objects. The prenatal ultrasonographic features of the three views of the aortic arch were carefully observed. The three views included the followings： the transverse view （the view of three vessels and trachea）, the sagittal view （the longitudinal view of the aortic arch）, and the coronal view （the coronal view of the descending aorta）. The prenatal diagnostic clues and diagnostic techniques of aortic arch anomalies were summarized and analyzed. Results Eighty-one cases with aortic arch anomalies were followed up. Fifteen cases were left-sided aortic arch and left-sided ductus arteriosus with aberrant right subclavian artery, 22 cases with right aortic arch and left-sided ductus arteriosus with aberrant left subclavian artery, 4 cases were mirror right aortic arch and left-sided ductus arteriosus, 2 cases were mirror right aortic arch and right-sided ductus arteriosus, 11 cases were double aortic arch, 23 cases were coarctation of the aorta, and 4 cases were interruption of aortic arch. Among them, 27 cases were complicated with other cardiac and extracardiac malformations and 13 cases with chromosomal abnormalities. Prenatal ultrasonographic clues for diagnosis of coarctation of the aorta included the three vessels and trachea view showing small diameter and disproportion to the diameter of the ductus arteriosus. And the longitudinal view of the aortic arch was helpful for showing the position and the extent of coarctation of the aorta. Prenatal ultrasonographic clues for diagnosis of interruption of aortic arch were that the three vessels and trachea view and the longitudinal view of the aortic arch showed the interruption between aortic arch and descending aorta. And the abnormal combination cases of the aortic arch segments also had their corresponding diagnostic clues. These clues included that the three vessels and trachea view showed abnormal position, arrangement and running of the branches of the aortic arch. And the coronal view of the descending aorta also showed abnormal changes in the branches of aortic arch. Conclusions Various types of congenital aortic arch anomalies have characteristic ultrasonography and their corresponding diagnostic clues and methods. The combined use of the three views of the aortic arch is effective in prenatal diagnosis for aortic arch anomalies.