1. Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University , Osaka , Japan
2. Department of Surgery, Surgical Oncology and Science, Sapporo Medical University , Sapporo , Japan
3. Department of Surgery, Koseiren Takaoka Hospital , Takaoka , Japan
4. Department of Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital , Tokyo , Japan
5. Department of Gastroenterological Surgery, Faculty of Medicine, Fukuoka University , Fukuoka , Japan
6. Division of Colon and Rectal Surgery, Shizuoka Cancer Center Hospital , Nagaizumi , Japan
7. Department of Surgery, Yokohama City University , Yokohama , Japan
8. Department of Coloproctological Surgery, Juntendo University Faculty of Medicine , Tokyo , Japan
9. Division of Lower GI, Department of Gastroenterological Surgery, Hyogo Medical University , Nishinomiya , Japan
10. Department of Surgery, Fujita Health University, School of Medicine , Toyoake , Japan
11. Department of Lower Gastrointestinal Surgery, Kitasato University School of Medicine , Sagamihara , Japan
12. Gastroenterological Center, Department of Gastroenterological Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research , Tokyo , Japan
13. Department of Gastrointestinal Surgery, Tokyo Medical and Dental University Graduate School of Medicine , Tokyo , Japan
14. Department of Surgery, Gastroenterological Center, Yokohama City University Medical Center , Yokohama , Japan
15. Department of Surgery, Kindai University Faculty of Medicine , Osakasayama , Japan
16. Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine , Yokohama , Japan
17. Department of Surgery, Keio University School of Medicine , Tokyo , Japan
18. Department of Gastroenterological Surgery, Toranomon Hospital , Tokyo , Japan
19. Department of Surgery, Southern TOHOKU Research Institute for Neuroscience, Southern TOHOKU General Hospital , Koriyama , Japan
20. Department of Colorectal Surgery, National Cancer Center Hospital , Tokyo , Japan
21. Department of Surgery, Osaka Red-Cross Hospital , Osaka , Japan
22. Department of Surgery, Kitasato University Kitasato Institute Hospital , Tokyo Japan