1. Department of Surgery Ageo Central General Hospital Ageo Japan
2. Department of Surgery Teikyo University School of Medicine Tokyo Japan
3. Hernia Center St. Luke's International Hospital Tokyo Japan
4. Division of Gastroenterological Surgery, Department of Surgery Aichi Medical University Nagakute Japan
5. Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences Nagoya Japan
6. Department of Surgery, Teine Keijinkai Medical Center Sapporo Japan
7. Department of Surgery Juntendo University Urayasu Hospital Urayasu Japan
8. Gastroenterological Surgery, Higashiosaka City Medical Center Higashiosaka Japan
9. Department of General Surgery Juntendo University Nerima Hospital Tokyo Japan
10. Department of Surgery and Science, Faculty of Medicine, Academic Assembly University of Toyama Toyama Japan
11. Department of Surgery, Surgical Oncology and Science Sapporo Medical University Sapporo Japan
12. Department of Surgery Nagoya Ekisaikai Hospital Nagoya Japan