[1] Hiroshima Univ, Grad Sch Biomed & Hlth Sci, Dept Gastroenterol & Transplant Surg, 1-2-3 Kasumi,Minami Ku, Hiroshima 7348551, Japan
[2] Hiroshima Univ Hosp, Hofu Inst Gastroenterol, Div Endoscop Surg, 14-33 Ekiminami Machi, Hofu, Yamaguchi 7470801, Japan
[3] Hiroshima Univ, Grad Sch Biomed & Hlth Sci, Dept Perioperat & Crit Care Management, 1-2-3 Kasumi,Minami Ku, Hiroshima 7348551, Japan
[4] Hofu Inst Gastroenterol, Dept Gastroenterol Surg, 14-33 Ekiminami Machi, Yamaguchi 7470801, Japan