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 @ % of the normal level ( controlled hypotension ) by using venous administration of Remifentanil about @ min after the operation .