CASE REPORTS
A case of isolated total anomalous pulmonary venous drainage type IIa: a dilated coronary sinus was the key finding to determine the fetal diagnosis
2021 Volume 48 Issue 3 Pages 127-132
Details
2021 Volume 48 Issue 3 Pages 127-132
Total anomalous pulmonary drainage (TAPVD) is a congenital anomaly that is extremely difficult to diagnose in the prenatal phase. However, it is essential that TAPVD is diagnosed during the prenatal period as some types of TAPVD require surgery soon after birth; moreover prompt treatment can affect the neonatal prognosis. In this article, we report our experience of prenatal diagnosis of isolated TAPVD type IIa with a dilated coronary sinus at 2nd trimester fetal ultrasound screening, along with a brief review of the literature. The patient was a 25-year-old primigravida without any medical or family history. At 20 weeks of gestation, 2nd trimester fetal ultrasound screening was performed. A partial atrioventricular septal defect (AVSD) was suspected. A partial midline defect in the heart was suspected, and the level of the atrioventricular valve appeared to be at nearly the same position in both ventricles. The images of other cardiac features were normal; when looking at the pulmonary vein for the first time, a connection to the left atrium (LA) was observed, at least in each of the right and left pulmonary venous connections. At 20 weeks of gestation, it was difficult to judge the direction of the blood flow. Thus, we decided to check it again after the fetus had grown. At 26 weeks of gestation, we found that the blood flow direction was from left to right, which is an unusual direction. The suspicion of partial AVSD was then rejected. The “septal defect” on the ultrasound image was actually a dilated coronary sinus. No features of persistent left superior vena cava (PLSVC), which is the most common anomaly when there is a dilated coronary sinus., were seen. Additionally, the pulmonary vein merged into the dilated coronary sinus. Based on these findings, we concluded that this was a case of isolated TAPVD type IIa. Therefore, we referred the patient to a tertiary hospital. In this case, a midline defect initially raised the suspicion of partial AVSD. After careful observation, however, we detected an unusual direction of the blood flow, and the resulting rejection of PLSVC led to a diagnosis of type IIa TAPVD.
