1. Committee of the Board Certification System for Expert Surgeons; Japanese Society of Hepato-Biliary-Pancreatic Surgery; Tokyo Japan
2. Database Committee; The Japanese Society of Gastroenterological Surgery; Tokyo Japan
3. The Japanese Society of Gastroenterological Surgery; Tokyo Japan
4. Department of Health Policy and Management, School of Medicine; Keio University; Tokyo Japan
5. Japanese Society of Hepato-Biliary-Pancreatic Surgery; Tokyo Japan