1. Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan
2. Department of Gastroenterology and Hepatology, Fujita Health University, Aichi, Japan
3. Department of Endoscopy, Nagoya University Hospital, Nagoya, Japan
4. Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan