1. Department of Surgery, Kosin University College of Medicine, Busan, Republic of Korea.
2. Department of Surgery, Chung-Ang University College of Medicine, Seoul, Republic of Korea.
3. Division of Upper Gastrointestinal Surgery, Department of Surgery, Korea University Anam Hospital, Seoul, Republic of Korea.
4. Department of Surgery, The Catholic University of Korea College of Medicine, Seoul, Republic of Korea.
5. Department of Surgery, Ajou University School of Medicine, Suwon, Republic of Korea.