 The visual analogue scale VAS is used to rate the pain, where 0 is no pain and 10 is the worst pain imaginable. Criteria for evaluation:1 effective: after spinal anesthesia finish, a dose that provide adequate sensory dermatomal anesthesia to pinprick to T6 or higher within 10 minutes, and the VAS is lower than or equal to 3 within 50minutes after operation begin; 2 ineffective: if the initial plane of sensory dermatomal anesthesia is lower than T6 or VAS is greater than 3 within 50 minutes after beginning of operationduring operation, the dose of ropivacaine is considered inadequate and additional lidocaine is given through epidural catheter. 