Takahiro Nakajima1, Shigetoshi Yoshida1, Ichiro Yoshino2. 1. Department of General Thoracic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. 2. Department of General Thoracic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. Electronic address: iyoshino@faculty.chiba-u.jp.