General anesthesia was performed by intravenous injection of Midazolam , Diprivan , Fentanyl and Cis-atracurium , sevoflurane-inhaling , Remifentanil , etc. , and the patient 's mean arterial pressure was maintained to be about 70 % of the normal level ( controlled hypotension ) by using venous administration of Remifentanil about 10 min after the operation .