1. Department of Gastroenterological Surgery II, Hokkaido University Faculty of Medicine , Sapporo , Japan
2. Second Department of Surgery, Wakayama Medical University , Wakayama , Japan
3. Department of General Surgery, Graduate School of Medicine, Chiba University , Chiba , Japan
4. Department of Surgery, Institute of Gastroenterology, Tokyo Woman's Medical University , Tokyo , Japan
5. Department of Gastroenterological Surgery, Osaka International Cancer Institute , Osaka , Japan
6. Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Graduate School of Medicine Kyoto University , Kyoto , Japan
7. Department of Surgery, Tohoku University Graduate School of Medicine , Sendai , Japan
8. Department of Advanced Medicine, Hiroshima University , Hiroshima , Japan
9. Division of Hepatobiliary and Pancreatic Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research , Tokyo , Japan
10. Department of Hepato-Biliary-Pancreatic Surgery, Tochigi Cancer Centre , Utsunomiya , Japan
11. Department of Hepato-Biliary-Pancreatic Surgery, Chiba Cancer Centre , Chiba , Japan
12. Department of Gastroenterological Surgery, Fujita Health University Bantane Hospital , Nagoya , Japan
13. Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan
14. Department of Hepato-Biliary-Pancreatic Surgery and Transplantation, Kanazawa University , Kanazawa , Japan
15. Department of Surgery, Kansai Medical University , Osaka , Japan
16. Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine , Yokohama , Japan
17. Department of Hepato-Biliary-Pancreatic Surgery, Osaka Metropolitan University Graduate School of Medicine , Osaka , Japan
18. Department of Surgery, Kindai University Faculty of Medicine , Osaka-sayama , Japan
19. Data Science Centre, Promotion Unit, Institute of Health Science Innovation for Medical Care, Hokkaido University Hospital , Sapporo , Japan