1. Department of Surgery, College of Medicine, Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
2. Division of Infectious Diseases, Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
3. Department of Surgery, College of Medicine, Seoul National University Bundang Hospital, Seoul, Korea.
4. Department of Surgery, College of Medicine, Seoul National University, Seoul, Korea.
5. Department of Surgery, College of Medicine, Soonchunhyang University, Seoul, Korea.