1. Department of Thoracic Surgery, Yokohama Minami Kyosai Hospital , 1-21-1, Mutsuurahigashi, Kanazawa-ku, Yokohama 236-0037, Kanagawa , Japan
2. Department of General Thoracic Surgery, Yokohama City University Hospital , 3-9, Fukuura, Kanazawa-ku, Yokohama 236-0004, Kanagawa , Japan