1. Department of Surgery, Teikyo University School of Medicine, Tokyo 173-8502, Japan
2. Department of Thoracic Surgery, Kanagawa Cardiovascular and Respiratory Center, Yokohama 236-0051, Japan
3. Department of Thoracic Surgery, Saitama Cardiovascular and Respiratory Center, Kumagaya 360-0197, Japan
4. Department of General Thoracic Surgery, Yokosuka Kyosai Hospital, Yokosuka 238-8558, Japan
5. Department of Thoracic Surgery, Yokohama Rosai Hospital, Yokohama 222-0036, Japan
6. Department of Thoracic Surgery, Yamagata Prefectural Central Hospital, Yamagata 990-2292, Japan
7. Department of Thoracic Surgery, National Hospital Organization Shikoku Cancer Center, Matsuyama 791-0245, Japan
8. Department of Surgery, Yokohama City University, Yokohama 236-0004, Japan
9. Department of Thoracic and Cardiovascular Surgery, Nara Medical University, Kashihara 634-8521, Japan