1. Division of Gastrointestinal Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
2. Institute of digestive surgery of Sichuan University, West China Hospital, West China school of medicine, Sichuan University, Chengdu, Sichuan, China
3. Colorectal Cancer Center, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China