This study was carried out to define the anatomical criteria for the diagnosis of inferior-type caval vein defect and compare the echocardiographic findings with surgical findings.
The records of 19 patients – 13 male and six female patients in the age group of 18 months to 27 years, who were diagnosed as inferior-type caval vein defect with or without anomalous drainage of right pulmonary vein(s) on echocardiography – were retrospectively reviewed and compared with surgical findings.
Surgical diagnosis of inferior-type caval vein defect was confirmed in 17 of the 19 patients. In two patients, the surgical diagnosis was that of a large fossa ovalis atrial septal defect – confluent defect and fossa ovalis atrial septal defect with deficient inferior rim in one patient each. Surgical diagnosis of anomalous drainage of pulmonary vein(s) was based on the course of the superior rim of the defect in relation to the pulmonary veins. Our echocardiographic impression of the pulmonary veins appearing in its normal position but showing abnormal drainage to right atrium was in agreement with the surgical notes. Discrepancy was found in the number of pulmonary veins draining anomalously. The discordance was related to overdiagnosis of anomalous drainage in all except one, that is, three out of four. In one, only the right lower pulmonary vein was diagnosed to be anomalous, whereas both right upper and lower pulmonary veins were found to be anomalous.
Echocardiography provides definite diagnosis of inferior-type caval vein defect. Inferior caval vein straddling and an intact fossa ovalis are prerequisites for diagnosis. Anomalous pulmonary venous drainage of the right pulmonary veins is very common in our series, although accurate diagnosis of the number of pulmonary veins was not possible in all cases. Multiple views on transthoracic echocardiography starting from the subxiphoid views delineate the morphology accurately. Transoesophageal echocardiography is required only in patients in whom the windows, especially the subxiphoid, are not adequate.