1. Department of Surgery, The Catholic University of Korea College of Medicine, Seoul, Korea.
2. Department of Surgery, Kyung Hee University School of Medicine, Seoul, Korea.
3. Department of Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
4. Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
5. Dr. Jang's Surgical Clinic, Seoul, Korea.
6. Department of Surgery and Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
7. Department of Surgery, Gangnam Severance Hospital, Yonsei University Health System, Seoul, Korea.