1. Department of Hepato‐Biliary‐Pancreatic Surgery Osaka City University Graduate School of Medicine Osaka Japan
2. Department of General and Gastroenterological Surgery Osaka Medical and Pharmaceutical University Osaka Japan
3. Department of Surgery, Hirakata Hospital Kansai Medical University Osaka Japan
4. Department of Surgery Nara Medical University Nara Japan
5. Second Department of Surgery Wakayama Medical University Wakayama Japan
6. Division of Digestive Surgery, Department of Surgery Kyoto Prefectural University of Medicine Kyoto Japan
7. Department of Surgery, Faculty of Medicine Kindai University Osaka Japan
8. Division of Gastrointestinal, Breast, and General Surgery, Department of Surgery Shiga University of Medical Science Otsu Japan