Yoshihide Nanno1, Hirochika Toyama2. 1. Department of Surgery, Division of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan. ynanno@med.kobe-u.ac.jp. 2. Department of Surgery, Division of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.