Usually the pulmonary veins come to a confluence behind the left atrium. Prior to birth, this confluence is supposed to connect to the heart. If it does not, the veins have to find another way to get back to the heart. Surgical treatment of Total Anomalous Pulmonary Venous Return involves reconnecting the pulmonary veins to the back of the left atrium, as in a normal heart.
The animation (left) shows the repair of the most common type (supracardiac). The left atrium and pulmonary veins are opened and sutured together (1). Notice that the vessel that connects the superior vena cava (SVC) with the pulmonary veins is removed (2). However, this is not always done by the surgeon. It may just be tied off as the blood will bypass this section when it is closed. The atrial septal defect is closed with a patch (3).
The post-operative recovery period depends on the exact nature of the defect, the procedure used to correct it and the condition of the neonate prior to repair. In those cases where there was an obstruction to the blood flow, corrective surgery may become urgent and the recovery may be more complicated, with a prolonged post-operative course. If the venous blood flow is unobstructed the hospital stay can be as short as 3 to 5 days.