1. Department of Surgery, Shiga University of Medical Science, Otsu, Shiga 520‑2192, Japan
2. Department of Surgery, Kansai Medical University, Hirakata, Osaka 573‑1191, Japan
3. Department of Gastroenterological Surgery, Osaka University Graduate School of�Medicine, Suita, Osaka 565‑0871, Japan
4. Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Osaka 569‑0801, Japan
5. Department of Surgery, Faculty of Medicine, Kinki University, Osaka-Sayama, Osaka 589‑0014, Japan
6. Department of Hepato‑Biliary‑Pancreatic Surgery, Osaka City University Graduate School of Medicine, Abeno, Osaka 545‑0051, Japan
7. Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565‑0871, Japan