Department of Gastroenterology, Japanese Red Cross Medical Center, Tokyo, Japan; Department of Gastroenterology, The University of Tokyo School of Medicine, Tokyo, Japan
2.Department of Gastroenterology, Japanese Red Cross Medical Center, Tokyo, Japan.
3.Department of Hepato-Biliary-Pancreatic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan
4.Department of Gastroenterology, The University of Tokyo School of Medicine, Tokyo, Japan.