1. Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
2. Division of Gastrointestinal Surgery, Department of Surgery, Seoul National University Hospital, Seoul, Korea.
3. Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Surgery, Al-Noor Specialist Hospital, Makkah, Saudi Arabia.
5. Department of Surgery, Gachon University Gil Medical Center, Incheon, Korea.
6. Division of Hepatobiliary Surgery, Department of Surgery, Seoul National University Hospital, Seoul, Korea.