Congenital partial pericardial defect discovered incidentally during surgery for lung cancer: a case report and literature review

BACKGROUND: Congenital pericardial defects are rare congenital anomalies, often asymptomatic and incidentally detected during thoracic surgery. CASE PRESENTATION: A 74-year-old man with primary lung cancer (cT1cN0M0, Stage IA3) underwent thoracoscopic radical lobectomy. At the time of thoracotomy, a pericardial defect was found on the ventral side of the hilar region, and the left atrial appendage was exposed. Due to concern that contact between the bronchial stump and the left atrial appendage may lead to postoperative bleeding and heart hernia, the pericardial defect was closed with an expanded polytetrafluoroethylene GoreTex® membrane. Preoperative computed tomography was reanalyzed with a 1 mm slice, congenital pericardial defect was detected as the pericardium had penetrated under the left atrial appendage. CONCLUSIONS: In congenital partial pericardial defect, contact between the left atrial appendage and bronchial stump, due to movement of the lung or heart, increases the risk of bleeding after lung resection. Therefore, closure of the defect should be considered. Although it is difficult to diagnose congenital partial pericardial defect preoperatively, computed tomography taken with a slice thickness of 1 mm is useful for diagnosis.