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

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 extra-cardiac 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. Key words: Ultrasonography, prenatal; Aortic arch anomalies; Diagnostic clues