1. Department of Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
2. Department of Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea2Department of Surgery, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
3. Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
4. Department of Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
5. Department of Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
6. Department of Surgery, Samsung Medical Center, Sungkyunkwan University College of Medicine, Seoul, Korea