Department of Surgery, Seoul St. Mary Hospital, College of Medicine, The Catholic University Hospital, Seoul, Korea. Department of Surgery, Incheon St. Mary's Hospital, College of Medicine, The Catholic University Hospital, Incheon, Korea. Department of Surgery, Eunpyeong St. Mary's Hospital, College of Medicine, The Catholic University Hospital, Seoul, Korea. Department of Surgery, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University Hospital, Daejeon, Korea. Department of Surgery, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Korea. Department of Surgery, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Korea. Department of Surgery, Hallym Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.