1. Department of Surgery Faculty of Medicine Kindai University Osaka‐Sayama Japan
2. Department of Surgery Hyogo Prefectural Nishinomiya Hospital Nishinomiya Japan
3. Department of Gastroenterological Surgery Osaka University Graduate School of Medicine Suita Japan
4. Department of Surgery National Hospital Organization Osaka National Hospital Osaka Japan
5. Department of Surgery Toyonaka Municipal Hospital Toyonaka Japan
6. Department of Surgery Sakai City Medical Center Sakai Japan
7. Department of Surgery Kansai Rosai Hospital Amagasaki Japan
8. Department of Gastroenterological Surgery Higashiosaka City Medical Center Higashiosaka Japan
9. Department of Surgery Osaka Police Hospital Osaka Japan
10. Department of Surgery Minoh City Hospital Minoh Japan
11. Department of Surgery Itami City Hospital Itami Japan
12. Department of Surgery JCHO Osaka Hospital Osaka Japan
13. Department of Gastroenterological Surgery Nagoya City University Graduate School of Medical Sciences Nagoya Japan