Atsushi Shiozaki1, Keita Katsurahara2, Eigo Otsuji2. 1. Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan. shiozaki@koto.kpu-m.ac.jp. 2. Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan.