1. Division of Hepatobiliary-pancreatic Surgery, Department of Surgery, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
2. Department of Surgery, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
3. Division of Hepatobiliary-Pancreatic Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Surgery, Ajou University Hospital, Ajou University College of Medicine, Suwon, Korea.
5. Department of Surgery, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.