An 82-year-old woman suddenly developed chest pain and apoplexy. Computed tomography (CT) showed acute type A aortic dissection, the true lumen in the brachicephalic artery was severely compressed by the faulse lumen. Pulsation in the either leg was not detected during induction of anesthesia. We evaluated the cerebral blood flow and lower extremity blood flow using near infrared spectroscopy (NIRS) during the operation, tissue oxygenation index (TOI) was continuously monitored during the operation. Cardiopulmonary bypass( CPB) was established by puncturing the true lumen in the ascending aorta and bicaval venous drainage. TOI was returned to normal range by CPB. Although the central repair (ascending aorta replacement) was performed, leg ischemia persisted. We performed ascending aorta-bifemoral bypass. After the operation, leg ischemia disappeared and CT revealed patency of the bypass graft. Postoperative course was uneventful without deterioration of neurological function. She was discharged 49 days after the operation.