[1] Univ Tokyo, Grad Sch Med, Dept Endoscopy & Endoscop Surg, Bunkyo Ku, Tokyo 1130033, Japan
[2] Jikei Univ, Sch Med, Dept Endoscopy, Tokyo, Japan
[3] Natl Canc Ctr, Endoscopy Div, Tokyo, Japan
[4] Canc Inst Hosp, Japanese Fdn Canc Res, Dept Gastroenterol, Tokyo, Japan
[5] Yokohama City Univ, Med Ctr, Gastroenterol Ctr, Yokohama, Kanagawa 232, Japan
[6] Shizuoka Canc Ctr, Div Endoscopy, Shizuoka, Japan
[7] Kobe Univ, Dept Gastroenterol, Kobe, Hyogo, Japan
[8] Niigata Univ Med & Dent Hosp, Dept Endoscopy, Niigata, Japan
[9] Osaka Med Ctr Canc & Cardiovasc Dis, Dept Gastrointestinal Oncol, Osaka, Japan
[10] Univ Ulsan, Coll Med, Div Gastroenterol, Asan Med Ctr, Seoul, South Korea
[11] Taipei Med Univ, Shuang Ho Hosp, Dept HepatoGastroenterol, Taipei, Taiwan
[12] Fudan Univ, Zhongshan Hosp, Endoscopy Ctr, Shanghai 200433, Peoples R China