1. Department of Gastrointestinal and Hepato‐Biliary‐Pancreatic Surgery Nippon Medical School Tokyo Japan
2. Department of Healthcare Quality Assessment, Graduate School of Medicine The University of Tokyo Tokyo Japan
3. Project Management Subcommittee The Japanese Society of Gastroenterological Surgery Tokyo Japan
4. Database Committee The Japanese Society of Gastroenterological Surgery Tokyo Japan
5. Department of Advanced Robotic and Endoscopic Surgery Fujita Health University Toyoake Japan
6. The Japanese Society of Gastroenterological Surgery Tokyo Japan