1. Department of Gastroenterological Surgery; Higashiosaka City General Hospital; Osaka Japan
2. Department of Gastroenterological Surgery; Osaka University Graduate School of Medicine; Osaka Japan
3. Department of Surgery; Osaka General Medical Center; Osaka Japan
4. Department of Surgery; Sakai City Hospital; Osaka Japan
5. Department of Surgery; Kinki Central Hospital; Hyogo Japan
6. Department of Surgery; NTT West Osaka Hospital; Osaka Japan
7. Department of Surgery; Kansai Rosai Hospital; Hyogo Japan