1. Department of Surgery; Kansai Medical University; Osaka Japan
2. Department of Mathematics; Kansai Medical University; Osaka Japan
3. Hepato-Biliary-Pancreatic Surgery Division; Department of Surgery; Graduate School of Medicine; The University of Tokyo; Tokyo Japan
4. Department of Surgery; Tokyo Women's Medical University; Tokyo Japan
5. Department of Gastroenterological Surgery; Graduate School of Life Sciences; Kumamoto University; Kumamoto Japan
6. Department of Surgery; Sapporo Kosei Hospital; Sapporo Japan
7. Department of Hepato-Biliary-Pancreatic Surgery; Osaka City University Graduate School of Medicine; Osaka Japan
8. Department of Gastroenterological Surgery I; Hokkaido University Graduate School of Medicine; Sapporo Japan
9. Department of Gastroenterological Surgery; Kanazawa University; Ishikawa Japan
10. Department of Gastroenterological and Transplant Surgery; Applied Life Sciences; Institute of Biomedical and Health Sciences; Hiroshima University; Hiroshima Japan
11. Department of Surgery; Korea University College of Medicine; Seoul Korea
12. Department of Surgery; Ajou University School of Medicine; Suwon Korea
13. Department of Surgery; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul Korea
14. Department of Surgery; Yonsei University College of Medicine; Seoul Korea
15. Center for Liver Cancer; National Cancer Center; Goyang Korea
16. Department of Surgery; Keimyung University Dongsan Medical Center; Daegu Korea
17. Department of Surgery; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
18. Department of Surgery; Dong-A University College of Medicine; Busan Korea
19. Department of Surgery; The Catholic University of Korea; Seoul Korea