1. Department of Surgery, Daejeon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
2. Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
3. Department of Surgery, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
4. Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
5. Department of Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
6. Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
7. Department of Surgery, Dong-A University College of Medicine, Busan, Korea.