Kitasato University - Department of Gastroenterology, Ehime Prefectural Central Hospital - Gastroenterology Center, University of Texas at Dallas - Division of Digestive and Liver Diseases, University of Michigan at Ann Arbor - Division of Gastroenterology and Hepatology, University of Michigan at Ann Arbor - Division of Gastroenterology and Hepatology, Ogaki Municipal Hospital - Department of Surgery, Ogaki Municipal Hospital - Department of Surgery, University of Texas at Dallas - Department of Surgery, University of Michigan at Ann Arbor - Division of Gastroenterology and Hepatology and University of Texas at Dallas - Division of Digestive and Liver Diseases