Prenatal echocardiographic diagnosis of superior vena cava abnormalities

Objective To improve the accuracy of prenatal echocardiography diagnosis by analyzing and summarizing the ultrasonic features of fetal superior vena cava abnormalities.Methods The echocardiographic features of 11 fetuses with abnormal superior vena cava were analyzed retrospectively.Results There were 9 cases of persistent left superior vena cava (or bilateral superior vena cava) in 11 fetuses. Isolated left superior vena cava were in 2 cases. The fetal echocardiography characters as following:Main section:Three-vessel trachea section. When the upper left cavity was persistent, this section presents "four-vessel sign". In the isolated upper left cavity, this section showed the superior vena cava on the left side of the pulmonary artery, and the right superior vena cava was absent. Auxiliary section:① In the four-cavity central incised surface, the transverse section of superior vena cava could be seen at the left margin of left atrium. ② In the low section of the four-cavity heart, dilated coronary sinus could be displayed. ③ In the left sagittal side view of thoracic and cervical part, the superior vena cava merged into the dilated coronary vein.Conclusions There are typical ultrasound images of abnormal superior vena cava in fetal period. The key to accurate diagnosis is to synthesize the features of the above-mentioned cross-sectional images.