1. Department of General & Gastroenterological Surgery Showa University
2. Department of Surgery, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital
3. Department of Surgery, Tokyo Metropolitan Hiroo Hospital
4. Department of Surgery, Kyorin University
5. Department of Surgery II, Tokyo Women's Medical University
6. Department of Surgery, Tokyo Women's Medical University Medical Center East
7. Department of Surgery, Toho University Ohashi Medical Center
8. Department of General and Gastroenterological Surgery, Toho University Medical Center Omori Hospital
9. Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Nippon Medical School
10. Department of Surgery, Gastroenterological Center, Yokohama City University