1. Department of Endoscopy; Hiroshima University Hospital; Hiroshima Japan
2. Department of Endoscopy; The Jikei University School of Medicine; Tokyo Japan
3. Department of Gastroenterology & Gastrointestinal Oncology; National Cancer Center Hospital East; Kashiwa Japan
4. Department of Gastroenterology; Kyoto Second Red Cross Hospital; Kyoto Japan
5. Department of Gastroenterology and Hematology; Graduate School of Medicine; Hirosaki University; Hirosaki Japan
6. Department of Gastrointestinal Oncology; Osaka Medical Center for Cancer and Cardiovascular Diseases; Osaka Japan
7. Department of Gastroenterology; National Hospital Organization Tokyo Medical Center; Tokyo Japan
8. Department of Medicine and Clinical Science; Graduate School of Medical Sciences; Kyushu University; Fukuoka Japan
9. Department of Gastrointestinal Medicine; St Mary's Hospital; Kurume Japan
10. Endoscopy Division; National Cancer Center Hospital; Tokyo Japan