1. Department of Surgery, Korea University College of Medicine Guro Hospital, Seoul, Korea
2. Department of Pediatrics, Korea University College of Medicine Guro Hospital, Seoul, Korea
3. Department of Surgery, Korea University College of Medicine Ansan Hospital, Gyeonggi-Do, Korea
4. Department of Surgery, Korea University College of Medicine Anam Hospital, Seoul, Korea
5. Department of Anesthesiology, Korea University College of Medicine Guro Hospital, Seoul, Korea
6. Department of Radiology, Korea University College of Medicine Guro Hospital, Seoul, Korea