1. Department of Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
2. Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
3. Department of Surgery, Dong-A University College of Medicine, Busan, Korea.
4. Department of Surgery, Insititute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.
5. Department of Surgery, Yeouido St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
6. Department of Surgery, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
7. Department of Surgery, Keimyung University School of Medicine, Daegu, Korea.
8. Department of Surgery, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
9. Department of Surgery, Chonbuk National University Hospital, Jeonju, Korea.
10. Department of Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
11. Department of Surgery, Chungnam National University Hospital, Daejeon, Korea.
12. Department of Surgery, Chonnam National University Medical School, Gwangju, Korea.
13. Department of Surgery, Ewha Womans University Mokdong Hospital, Seoul, Korea.