1. Department of Hepato-Biliary-Pancreatic Surgery; Osaka City University Graduate School of Medicine; Osaka Japan
2. Department of Surgery; Institute of Gastroenterology; Tokyo Women's Medical University; 1-4-3 Kawada-cho, Shinjuku-ku 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. Division of Hepato-Biliary-Pancreatic Surgery; Department of Surgery; Tohoku University Graduate School of Medicine; Sendai Japan
8. Department of Surgery; Institute of Health Biosciences; The University of Tokushima Graduate School; Tokushima Japan
9. Second Department of Surgery; Wakayama Medical University; Wakayama Japan
10. Department of Surgery; Teikyo University School of Medicine; Tokyo Japan