Cavopulmonary window: an extreme form of sinus venosus defect.

We present an unusual variant of the sinus venosus defect in which an obvious window is formed between a single pulmonary vein and the superior vena cava, the pulmonary vein retaining its connection to the left atrium. Two patients were operated on via right anterior minithoracotomy. A large single right pulmonary vein was found connecting to the left atrium. There was a large side-to-side communication between the superior vena cava and the pulmonary vein resulting in partially anomalous pulmonary venous drainage. A side-biting clamp was applied in the superior vena cava and the pulmonary vein at both sides of the communication, and the vein was divided. The incision in both veins was closed with a running suture.