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