1. Department of General Surgery, Peking Union Medical College Hospital, CAMS&PUMC, Beijing, China
2. Department of General Surgery, Zhongshan Hospital Fudan University, Shanghai, China
3. Department of General Surgery, The PLA General Hospital of China, Beijing, China
4. Department of General Surgery, Peking University People’s Hospital, Beijing, China
5. Department of General Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China