Anomalous drainage of pulmonary veins is seen, with right and left pulmonary veins draining into a common chamber, draining into the vertical vein, joining the innominate vein, and ultimately draining into a dilated superior vena cava.
As it is a supracardiac total anomalous pulmonary venous connection, a large atrial septal defect can be seen for draining into left atrium. No direct connection between pulmonary veins and left atrium is seen.
Diagnosis was confirmed intra-operatively, however surgery was abandoned due to the inherent risk of ligating the markedly dilated innominate vein.