1. Department of Community Medicine Fujita Health University Toyoake Japan
2. Department of Gastroenterological Surgery Fujita Health University Nagoya Japan
3. Department of Gastroenterological Surgery Yokohama City University Graduate School of medicine Yokohama Japan
4. Division of Digestive and General Surgery Niigata University Graduate School of Medical and Dental Sciences Niigata Japan
5. Department of Gastroenterological Surgery II Faculty of Medicine Hokkaido University Sapporo Japan
6. Second Department of Surgery School of Medicine Wakayama Medical University Wakayama Japan
7. Department of Surgery Institute of Gastroenterology Tokyo Women's Medical University Tokyo Japan