1 Department of Surgery, Yokohama City University, Yokohama, Japan. survey-adm@umin.net.
2 Department of General Surgical Science, Division of Biosystem Medicine, Subdivision of Oncology, Course of Medical Sciences, Gunma University Graduate School of Medicine, Gunma, Japan.
3 Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
4 Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, Tokyo, Japan.
5 Department of Thoracic Surgery, Jichi Medical University, Tochigi, Japan.
6 Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Osaka, 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 Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women's Medical University, Tokyo, Japan.
10 Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Miyagi, Japan.
11 Second Department of Surgery, University of Occupational and Environmental Health, Fukuoka, Japan.
12 Department of Cardiovascular Surgery, Kawasaki Medical School, Okayama, Japan.
13 Department of Gastroenterological Surgery, National Kyushu Cancer Center, Fukuoka, Japan.
14 Department of General Thoracic Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan.