1. Department of Surgery Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital Tokyo Japan
2. Department of Surgery Coloproctology Center Takano Hospital Kumamoto Japan
3. Department of Gastroenterological Surgery Ishikawa Prefectural Central Hospital Kanazawa Japan
4. Department of Gastroenterological Surgery Graduate School of Life Sciences Kumamoto University Kumamoto Japan
5. Department of Colorectal Surgery National Cancer Center East Kashiwa Japan
6. Department of General and Gastroenterological Surgery Toho University Omori Medical Center Tokyo Japan
7. Department of Surgery National Defense Medical College Tokorozawa Japan
8. Department of Surgery Tochigi Cancer Center Utsunomiya Japan
9. Saiseikai Yokohama‐shi Nanbu Hospital Yokohama Japan
10. Department of Surgery Kyoto University Kyoto Japan
11. Tokyo Medical and Dental University Tokyo Japan