1. Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, Tsurumai-cho, Showa-ku, Nagoya, Japan
2. Department of Surgery and Science, Faculty of Medicine, Academic Assembly, University of Toyama, Sugitani, Toyama, Japan
3. Second Department of Surgery, Wakayama Medical University, Kimiidera, Wakayama, Japan
4. Department of Surgery, Kindai University Faculty of Medicine, Ono-higashi, Osaka-Sayama, Japan
5. Department of Surgery, Oita Red Cross Hospital, Chiyo-machi, Oita, Japan
6. Department of Gastroenterological Surgery, Kumamoto University Graduate School of Medical Science, Honjo, Chuo-ku, Kumamoto, Japan
7. Department of Gastroenterological and General Surgery, Showa University School of Medicine, Hatanodai, Shinagawa-ku, Tokyo, Japan
8. Division of Hepato-Biliary Pancreatic Surgery, Tohoku University Graduate School of Medicine, Seiryo-cho, Aoba-ku, Sendai, Japan
9. Department of Surgery, Kansai Medical University, Shinmachi, Hirakata, Japan
10. Department of Surgery, National Defense Medical College, Namiki, Tokorozawa, Saitama, Japan
11. Department of Gastroenterological Surgery, Hyogo College of Medicine, Mukogawa, Nishinomiya, Hyogo, Japan
12. Department of Surgery, Hiroshima University Graduate School of Biomedical and Health Sciences, Kasumi, Minami-ku, Hiroshima, Japan
13. Department of Gastroenterological Surgery, Fujita Health University Bantane Hospital, Otobashi, Nakagawa-ku, Nagoya, Japan
14. Department of Surgery, Nara Medical University School of Medicine, Shijo-cho, Kashihara, Nara, Japan
15. Department of Surgery, Japan Organization of Occupational Health and Safety, Kansai Rosai Hospital, Inabaso, Amagasaki, Japan
16. Clinical Study Support Center, Wakayama Medical University, Kimiidera, Wakayama, Japan