[1] Nagoya Univ, Grad Sch Med, Dept Gastroenterol & Hepatol, Nagoya, Aichi 4668550, Japan
[2] Nagoya Univ, Grad Sch Med, Dept Surg, Div Surg Oncol, Nagoya, Aichi 4668550, Japan
[3] Nagoya Univ Hosp, Dept Endoscopy, Nagoya, Aichi, Japan
[4] Fujita Hlth Univ, Sch Med, Dept Gastroenterol, Toyoake, Aichi 47011, Japan