1. Department of Surgery, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
2. Department of Surgery, Kansai Medical University, Osaka, Japan
3. Division of Gastroenterological Surgery, Department of Surgery, Tohoku University, Sendai, Japan
4. Department of Surgery, Nara Medical University, Nara, Japan
5. Second Department of Surgery, Wakayama Medical University, Wakayama, Japan, Japan
6. Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
7. Department of Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Centre, Komagome Hospital, Tokyo, Japan
8. Hiroshima University, Hiroshima
9. Kobe University Graduate School of Medicine, Kobe
10. Wakayama Medical University, Wakayama
11. Tokyo Metropolitan Cancer and Infectious Diseases Centre, Komagome Hospital, Tokyo
12. Nara Medical University, Nara
13. Kansai Medical University, Osaka
14. Tohoku University, Sendai