1. Division of Hepatobiliary and Pancreatic Surgery, The Catholic University of Korea Incheon St. Mary’s Hospital, Incheon, Korea.
2. Department of Surgery, Yongin Severance Hospital, Yongin, Korea.
3. Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
4. Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.