1. Department of Gastrointestinal and Hepato‐Biliary‐Pancreatic Surgery Nippon Medical School Bunkyo‐ku Japan
2. Clinical Trial Committee of the Japan Society for Surgical Infection Chiyoda‐ku Japan
3. Department of Surgery Nippon Medical School Tama Nagayama Hospital Nagahama Japan
4. Department of Surgery Mazda Hospital Hiroshima Japan
5. Department of Gastroenterological Surgery Osaka City General Hospital Osaka Japan
6. Department of Surgery, Graduate School of Biochemical and Health Sciences Hiroshima University Hiroshima Japan
7. Department of Infection Control and Prevention Nippon Medical School Musashikosugi Hospital Kawasaki Japan
8. Department of Surgery Nagahama Red Cross Hospital Nagahama Japan
9. Department of Surgery Toho University Ohashi Medical Center Kashiwa Japan
10. Department of Esophageal Surgery National Cancer Center Hospital East Kashiwa Japan
11. Department of Surgery National Defense Medical College Saitama Japan
12. Department of Gastroenterological, Breast and Endocrine Surgery Yamaguchi University Graduate School of Medicine Yamaguchi Japan
13. Department of Gastroenterological Surgery Kochi Health Sciences Center Kochi Japan
14. Department of Gastrointestinal and Pediatric Surgery, Division of Reparative Medicine, Institute of Life Sciences Mie University Graduate School of Medicine Tsu Japan
15. Department of Digestive Surgery Tsuchiura Kyodo General Hospital Ibaraki Japan
16. Department of Digestive Surgery Nippon Medical School Musashikosugi Hospital Kawasaki Japan
17. Department of Surgery Nippon Medical School Chiba Hokusoh Hospital Inzai Japan
18. Japan Society for Surgical Infection Tokyo Japan
19. Department of Surgery Keio University School of Medicine Shinjuku‐ku Japan