1. Department of General Surgery, West China Hospital of Sichuan University , Chengdu , China
2. Breast Centre, West China Hospital of Sichuan University , Chengdu , China
3. Day Surgery Centre, West China Hospital of Sichuan University , Chengdu , China
4. Day Surgery Centre, Department of Anaesthesiology, West China Hospital of Sichuan University , Chengdu , China