1. Department of Biliary-Pancreatic Surgery; Fujita Health University; Toyoake Aichi Japan
2. Chiba University Graduate School of Medicine; Chiba Japan
3. Teikyo University School of Medicine; Tokyo Japan
4. Kanazawa University School of Medicine; Kanazawa Japan
5. National Hospital Organization; Tokyo Japan
6. Nagoya University Graduate School of Medicine; Nagoya Japan
7. Hokkaido University Graduate School of Medicine; Sapporo Japan
8. School of Medicine; Wakayama Medical University; Wakayama Japan
9. Tokyo Women's Medical University; Tokyo Japan
10. Tokushima University School of Medicine; Tokushima Japan
11. Kurume University School of Medicine; Kurume Japan