1. Second Department of Surgery School of Medicine Wakayama Medical University Wakayama Japan
2. Clinical Study Support Center School of Medicine Wakayama Medical University Wakayama Japan
3. Department of Gastrointestinal and Pediatric Surgery Tokyo Medical University Tokyo Japan
4. Department of Surgery Taipei Veterans General Hospital National Yang Ming University Taipei Taiwan
5. Department of Surgery Kindai University Faculty of Medicine Osaka Japan
6. Department of Surgery Kansai Medical University Osaka Japan
7. Department of General Surgery Graduate School of Medicine Chiba University Chiba Japan
8. Division of Hepato‐Biliary Pancreatic Surgery Kochi Health Sciences Center Kochi Japan
9. Department of Surgery Graduate School of Medicine Tohoku University Miyagi Japan
10. Department of Surgical Oncology Graduate School of Medicine Osaka City University Osaka Japan
11. Department of Surgery Hiroshima University Hiroshima Japan
12. Department of Gastroenterological Surgery II Hokkaido University Faculty of Medicine Hokkaido Japan
13. Department of Surgery Kurashiki Central Hospital Okayama Japan
14. Department of Surgery Osaka National Hospital Osaka Japan
15. Department of Surgery National Cheng‐Kung University Hospital Institute of Clinical Medicine National Cheng Kung University Tainan Taiwan
16. Division of Gastroenterological and General Surgery St. Marianna University School of Medicine Kanagawa Japan
17. Department of Surgery School of Medicine Iwate Medical University Iwate Japan
18. Department of Surgery Hiroshima City Hiroshima Citizens Hospital Hiroshima Japan
19. Department of Surgery Osaka Medical College Osaka Japan
20. Department of Surgery Chang Gung Memorial Hospital College of Medicine Chang Gung University Taoyuan City Taiwan
21. Department of Surgery Nagaoka Chuo General Hospital Niigata Japan
22. Institute of Gastroenterology Tokyo Women’s Medical University Tokyo Japan