1. Department of Surgery, Gangnam Severance Hospital; Yonsei University College of Medicine; Seoul Korea
2. Department of Surgery; Seoul National University Hospital, Seoul National University College of Medicine; Seoul Korea
3. Department of Surgery; Seoul National University Bundang Hospital, Seoul National University College of Medicine; Seongnam Korea
4. Department of Surgery, Severance Hospital; Yonsei University College of Medicine; Seoul Korea
5. Department of Surgery, Samsung Medical Center; Sungkyunkwan University College of Medicine; Seoul Korea