A 54-year-old man was admitted to our hospital because of chest discomfort. Cardiac catheterization revealed partial anomalous pulmonary venous connection with an intact atrial septum. The right upper pulmonary vein (RUPV) drained into the upper segment of the superior vena cava (SVC). Using the Williams procedure, an atrial septal defect (ASD) was created and a fresh autologous pericardial patch was used to fashion a new pulmonary vein return route from SVC to the ASD. Although the patient was stable after the procedure, he was admitted again 6 months later because of obstruction of RUPV. At reoperation, it was found that the previous pulmonary vein route was obstructed and that the pericardial baffle had adhered to the atrial septum above the ASD. The shrunken and thickened pericardial baffle was removed and the orifice of the ASD was extensively enlarged, after which an expanded polytetrafluoroethylene (ePTFE) patch was used as a new baffle. After the reoperation, the patient's condition improved.