[Acute Aortic Dissection Escaping Cardiac Tamponade due to Congenital Pericardial Defect:Report of a Case].

The natural course of Stanford type A acute aortic dissection (AAAD) has a poor prognosis. Early diagnosis is crucial, but in clinical practice some patients do not have typical symptoms, leading to a delay in diagnosis. We encountered a patient who complained only of shoulder pain and moderate respiratory distress. A chest computed tomography( CT) examination showed a dilated ascending aorta and a massive left hemothorax with minimal pericardial effusion. Intraoperative findings revealed aortic dissection of the ascending aorta and a congenital defect on the left pericardium. We performed graft replacement of the aortic root and ascending aorta. Usually, cardiac tamponade is a fatal complication of AAAD. However, in this case, the congenital pericardial defect drained the hemorrhage into the thoracic cavity and relieved cardiac tamponade. AAAD with a congenital pericardial defect may present clinically atypical. In this case, the patient could be saved by surgery without developing circulatory failure due to cardiac tamponade.