Munetaka Masuda1, Shunsuke Endo2, Shoji Natsugoe3, Hideyuki Shimizu4, Yuichiro Doki5, Yasutaka Hirata6, Junjiro Kobayashi7, Noboru Motomura8, Kiyoharu Nakano9, Hiroshi Nishida10, Morihito Okada11, Yoshikatsu Saiki12, Aya Saito13, Yukio Sato14, Kazuo Tanemoto15, Yasushi Toh16, Hiroyuki Tsukihara17, Shinji Wakui18, Hiroyasu Yokomise19, Kohei Yokoi20, Yutaka Okita21. 1. Department of Surgery, Yokohama City University, Yokohama, Japan. survey-adm@umin.net. 2. Department of Thoracic Surgery, Jichi Medical University, Tochigi, Japan. 3. Department of Digestive Surgery and Breast and Thyroid Surgery, Kagoshima University, Kagoshima, Japan. 4. Department of Cardiovascular Surgery, Keio University, Tokyo, Japan. 5. Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Osaka, Japan. 6. Department of Cardiac Surgery, The University of Tokyo Hospital, Tokyo, Japan. 7. Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan. 8. Department of Cardiovascular Surgery, Toho University, Sakura Medical Center, Chiba, Japan. 9. Harajuku Rehabilitation Hospital, Tokyo, Japan. 10. Rehabilitation, Tokyo Shinagawa Hospital, Tokyo, Japan. 11. Department of Surgical Oncology, Hiroshima University, Higashihiroshima, Japan. 12. Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Miyagi, Japan. 13. Division of Cardiovascular Surgery, Faculty of Medicine, Sakura Medical Center, Toho University, Tokyo, Japan. 14. Department of Thoracic Surgery, University of Tsukuba, Tsukuba, Japan. 15. Department of Cardiovascular Surgery, Kawasaki Medical School, Okayama, Japan. 16. Department of Gastroenterological Surgery, National Kyushu Cancer Center, Fukuoka, Japan. 17. Department of Cardiothoracic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. 18. Nihon University Hospital Cardiovascular Surgery, Tokyo, Japan. 19. Department of General Thoracic Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan. 20. Department of Thoracic Surgery, Nagoya University Graduate School of Medicine, Aichi, Japan. 21. Cardio-aortic Center, Takatsuki General Hospital, Osaka, Japan.