Tomoki Makino1, Takeo Hara2, Yuichiro Doki2. 1. Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Suita City, Osaka, Japan. tmakino@gesurg.med.osaka-u.ac.jp. 2. Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Suita City, Osaka, Japan.