1. Second Department of Surgery; Wakayama Medical University; Wakayama Japan
2. Department of Surgery, Institute of Gastroenterology; Tokyo Women's Medical University; 8-1 Kawadacho Shinjyukuku Tokyo 162-8666 Japan
3. Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery; Tokyo University Graduate School of Medicine; Tokyo Japan
4. Division of Surgical Oncology, Department of Surgery; Nagoya University Graduate School of Medicine; Nagoya Japan
5. Department of General Surgery; Chiba University Graduate School of Medicine; Chiba Japan
6. Department of Surgical Oncology; Hokkaido University Graduate School of Medicine; Sapporo Japan
7. Department of Hepato-Biliary-Pancreatic Surgery; Osaka City University Graduate School of Medicine; Osaka Japan
8. Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery; Tohoku University Graduate School of Medicine; Sendai Japan
9. Department of Surgery, Institute of Health Biosciences; The University of Tokushima Graduate School; Tokushima Japan
10. Japanese Society of Hepato-Biliary-Pancreatic Surgery, Department of Surgery; Teikyo University School of Medicine; Tokyo Japan