A 51-year-old suddenly developed severe chest and back pains. The diagnosis was acute aortic dissection of Stanford type A, but the dissecting space was not observed by enhanced CT scan. Medical treatment was started as early thrombosed aortic dissection. The blood pressure was sufficiently controlled, and the symptom was gradually improved. On the 8th hospital day, a severe chest pain appeared again, Enhanced CT scan showed an enlarged dissecting space, pericardial and pleural effusion. These findings were considered a redissected impending rupture, so the emergency operation was performed. Fresh clots were observed in the dissecting space of ascending aorta, but the intimal tear was not found in any portion of the examined aorta. Therefore total arch replacement was needed to resect the wall which may be responsible for the dissection and to reduce the residual dissecting space. The patient recovered without complications. Postoperative CT scan revealed no residual false lumen in the distal descending aorta.