Rare venous connection causing severe hypoxia after Fontan operation.

We describe a rare case of cyanosis following the Fontan operation with right-to-left shunting at the venous level, that is, an azygos venous to pulmonary venous connection. Few cases with partial anomalous pulmonary venous connection to azygos vein have been reported; however, there have been no reports describing the connection from azygos vein to pulmonary vein, which results in desaturation after Fontan operation. Multidetector-row computed tomography (MDCT) was a useful tool to depict this vascular malformation.