Yoo-Min Kim1, Kazutaka Obama2, Woo Jin Hyung3. 1. Department of Surgery, CHA Bundang Medical Center, CHA University, Seongnam-si, Republic of Korea. 2. Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan. 3. Department of Surgery, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, 120-752, Republic of Korea. wjhyung@yuhs.ac.