1. Department of Gastroenterological Surgery, Graduate School of Life Sciences; Kumamoto University; Kumamoto Japan
2. Department of Surgery; Iwate Medical University School of Medicine; Iwate Japan
3. Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine; University of Tokyo; Tokyo Japan
4. Department of Hepatobiliary and Pancreatic Surgery; National Cancer Center Hospital East; Kashiwa Chiba Japan
5. Department of Surgery, Surgical Oncology and Science; Sapporo Medical University School of Medicine; Sapporo Japan
6. Department of Surgery; Institute of Gastroenterology, Tokyo Women's Medical University; Tokyo Japan
7. Department of General and Gastroenterological Surgery; Osaka Medical College; Osaka Japan
8. Department of Gastrointestinal Hepato-Biliary-Pancreatic Surgery; Nippon Medical School; Tokyo Japan
9. Department of Surgery; Toho University Ohashi Medical Center; Tokyo Japan
10. Department of Gastroenterological Surgery; Dokkyo Medical University; Tochigi Japan
11. Department of Surgery; Osaka University Graduate School of Medicine; Suita Osaka Japan
12. Department of Surgery; Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital; Tokyo Japan
13. Medical Quality Management Center; Kumamoto University Hospital; Kumamoto Japan
14. Department of Healthcare Quality Assessment, Graduate School of Medicine; The University of Tokyo; Tokyo Japan
15. Department of Surgery and Oncology, Graduate School of Medical Sciences; Kyushu University; Fukuoka Japan
16. Deparment of Surgery; Toho University Faculty of Medicine; Tokyo Japan
17. Second Department of Surgery; Wakayama Medical University, School of Medicine; Wakayama Japan
18. Department of General Surgery; Chiba University Graduate School of Medicine; Chiba Japan
19. Japanese Society of Hepato-biliary-Pancreatic Surgery, Department of Surgery; Teikyo University School of Medicine; Tokyo Japan