Hideyuki Shimizu1, Shunsuke Endo2, Shoji Natsugoe3, Yuichiro Doki4, Yasutaka Hirata5, Junjiro Kobayashi6, Noboru Motomura7, Kiyoharu Nakano8, Hiroshi Nishida9, Morihito Okada10, Yoshikatsu Saiki11, Aya Saito7, Yukio Sato12, Kazuo Tanemoto13, Yasushi Toh14, Hiroyuki Tsukihara15, Shinji Wakui16, Hiroyasu Yokomise17, Munetaka Masuda18, Kohei Yokoi19, Yutaka Okita20. 1. Department of Cardiovascular Surgery, Keio University, 35, Shinanomachi, Shinjuku-ku, Tokyo, Japan. survey-adm@umin.net. 2. Department of Thoracic Surgery, Jichi Medical University, Shimotsuke, Japan. 3. Department of Digestive Surgery and Breast and Thyroid Surgery, Kagoshima University, Kagoshima, Japan. 4. Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita, Japan. 5. Department of Cardiac Surgery, The University of Tokyo Hospital, Tokyo, Japan. 6. Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Suita, Japan. 7. Department of Cardiovascular Surgery, Toho University, Sakura Medical Center, Sakura, Japan. 8. Harajuku Rehabilitation Hospital, Tokyo, Japan. 9. Rehabilitation, Tokyo Shinagawa Hospital, Tokyo, Japan. 10. Department of Surgical Oncology, Hiroshima University, Higashihiroshima, Japan. 11. Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan. 12. Department of Thoracic surgery, University of Tsukuba, Tsukuba, Japan. 13. Department of Cardiovascular Surgery, Kawasaki Medical School, Kurashiki, Japan. 14. Department of Gastroenterological Surgery, National Kyushu Cancer Center, Fukuoka, Japan. 15. Department of Cardiothoracic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. 16. Cardiovascular Surgery, Nihon University Hospital, Tokyo, Japan. 17. Department of General Thoracic Surgery, Faculty of Medicine, Kagawa University, Kida-gun, Kagawa, Japan. 18. Department of Surgery, Yokohama City University, Yokohama, Japan. 19. Department of Thoracic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan. 20. Cardio-aortic Center, Takatsuki General Hospital, Takatsuki, Japan.