Factor Analysis of the Missed Diagnosis of Total Anomalous Pulmonary Venous Connection in Prenatal Echocardiography.

Aim: This study investigated the major factors contributing to the missed diagnosis of total anomalous pulmonary venous connection (TAPVC) in fetal echocardiography.

Methods: We retrospectively analyzed the prenatal ultrasonic images of 32 fetuses with missed diagnoses of TAPVC, compared them with autopsy and postnatal surgical records, and summarized the most likely reasons leading to the missed diagnoses.

Results: We studied a total of 157 fetuses with TAPVC, 32 (20.3%) of whom were missed in prenatal echocardiography. The main factors for the missed diagnoses of TAPVC in the 32 fetuses were anatomic variants leading to the formation of a false pulmonary venous horn-like structure, the combination of TAPVC with other intracardiac anomalies, difficulty or inability to show the course and abouchement of TAPVC on conventional color Doppler flow imaging (CDFI), and excessive color flow gain, with a rate of approximately 53.1% (17/32). A decreased left atrial size and augmentation of the PLAS index may be indicators of false pulmonary venous horn-like structure.

Conclusion: False pulmonary venous horn-like structures due to anatomic variants are a major factor in the missed diagnosis of fetal TAPVC. The presence of pulmonary venous horn-like structure in a four-chamber view does not completely exclude TAPVC.