Fetal echocardiographic diagnosis of vascular rings

Objective. The purpose of this series is to describe the prenatal echocardiographic findings of vascular rings. Methods. The 3-vessel and trachea view consists of the axial view of the upper mediastinum. The normal left aortic arch appears as a V-shaped confluence of the ductus arteriosus and aortic arch, with the trachea situated posterior and to the right. No vessel should encircle the trachea. The diagnoses of vascular rings were made prenatally and were confirmed in all patients postnatally. Results. Six fetuses had diagnoses of vascular rings. The mean gestational age at diagnosis was 23.3 weeks (range, 18-31 weeks). The indications for fetal echocardiography were family history of congenital heart disease, echogenic focus in the left ventricle, and abnormal 4-chamber view. There were 2 fetuses with a double aortic arch; 3 fetuses with a right aortic arch, an aberrant left subclavian artery, and a left ductus arteriosus; and 1 with a right circumflex aortic arch with a left ductus arteriosus and an aberrant left subdavian artery. Two fetuses had associated structural cardiac defects, 1 with an unbalanced atrioventricular septal defect and trisomy 21 and the other with a double-outlet right ventricle, pulmonary atresia, and multiple other congenital anomalies. Conclusions. Vascular rings can be accurately diagnosed prenatally with recognition of a vascular structure that courses around the trachea and absence of the usual V-shaped relationship of the aortic and ductal arches. The color Doppler findings and the presence of a ductus arteriosus aid in identifying various components of the vascular ring.