1. Division of Gastrointestinal Surgery, Department of General Surgery, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu 610041, China
2. Department of Gastrointestinal Surgery, Division of Gastroenterology, West China Xiamen Hospital of Sichuan University, Xiamen, China
3. Department of Intensive Care Unit, West China Hospital of Sichuan University, Chengdu, China
4. Institute of Digestive Surgery, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Chengdu, Sichuan, China.