Abstract
We present a rare case of acute type A dissection which developed compression of the true lumen after starting cardiopulmonary bypass (CPB) with femoral arterial return. In this case, the entry was located in the proximal descending thoracic aorta, and the dissection expanded up to the ascending aorta in a retrograde direction. After starting CPB, the false lumen suddenly enlarged and the true lumen was compressed. We observed those changes by intraoperative transesophageal echocardiography, so the perfusion was stopped immediately. A long arterial cannula (Wessex) was inserted from the left ventricular apex with the tip of the cannula remaining in the true lumen of the ascending aorta, and antegrade perfusion was restarted. After that we could maintain adequate extracorporeal perfusion and the replacement of the total aortic arch was completed uneventfully.