1. Department of General Surgery, Lanzhou University Second Hospital, Cuiyingmen 82, Chengguan District, Lanzhou 730030, China
2. Hepato-Biliary-Pancreatic Institute, Lanzhou University Second Hospital, Lanzhou 730030, China
3. Gansu Provincial-Level Key Laboratory of Digestive System Tumors, Lanzhou 730030, China
4. Department of General Surgery, Gansu Provincial Second Hospital, Lanzhou 730030, China