1. Department of Surgery; Pippu Clinic; Pippu, Town Kamikawa-Gun Hokkaido Japan
2. Department of Gastroenterology and Hepatology; Okayama University; Okayama City Japan
3. Department of Surgery; Sapporo Hokuyu Hospital; Shiroishi-Ku Sapporo City Japan
4. Department of Surgery; Nihon University; Chiyoda-Ku Tokyo Japan
5. Department of Radiology; Jikei University; Tokyo Japan
6. Department of Surgery; Asahikawa Medical University; Asahikawa City Japan