1. Department of Surgery; Tohoku Rosai Hospital; Sendai Japan
2. First Department of Surgery; University of Fukui; Fukui Japan
3. Department of Surgery; Iwate Medical University School of Medicine; Morioka Japan
4. Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery; Nippon Medical School; Tokyo Japan
5. Department of Gastroenterology; Teikyo University Mizonokuchi Hospital; Kawasaki Japan