1. Department of Surgery; Iwate Medical University School of Medicine; Iwate Japan
2. Department of Gastroenterological Surgery; Graduate School of Life Sciences, Kumamoto University; Kumamoto Japan
3. Department of Hepatobiliary and Pancreatic Surgery; Graduate School of Medicine, Tokyo Medical and Dental University; Tokyo Japan
4. Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery; Graduate School of Medicine, University of Tokyo; Tokyo Japan
5. Department of Hepatobiliary and Pancreatic Surgery; National Cancer Center Hospital East; Kashiwa Chiba Japan
6. Department of Surgery; Graduate School of Medicine, Kyoto University; Kyoto Japan
7. Department of Surgery; Fujita Health University School of Medicine; Aichi Japan
8. Department of Surgery, Surgical Oncology and Science; Sapporo Medical University School of Medicine; Sapporo Japan
9. Department of Gastroenterological Surgery I; Hokkaido University Graduate School of Medicine; Sapporo Japan
10. Department of Surgery and Science; Graduate School of Medical Sciences, Kyushu University; Fukuoka Japan
11. Department of Hepato-Biliary-Pancreatic Surgery; Osaka City University Graduate School of Medicine; Osaka Japan
12. Department of Gastrointestinal Hepato-Biliary-Pancreatic Surgery; Nippon Medical School; Tokyo Japan
13. Department of Healthcare Quality Assessment; Graduate School of Medicine, The University of Tokyo; Tokyo Japan
14. Department of Digestive Surgery; Kawasaki Medical School; Okayama Japan
15. Department of Surgery; Toho University Faculty of Medicine; Tokyo Japan
16. Second Department of Surgery; Wakayama Medical University, School of Medicine; Wakayama Japan
17. Department of General Surgery; Chiba University Graduate School of Medicine; Chiba Japan
18. Japanese Society of Hepato-biliary-Pancreatic Surgery, Department of Surgery; Teikyo University School of Medicine; Tokyo Japan