1. The Department of Cardiovascular Surgery, Numata Neurosurgery Heart-Disease Hospital, Numata, Gunma, Japan
2. The Department of Cardiovascular Surgery, Heart Institute of Japan, Tokyo Womens Medical University, Tokyo, Japan
3. The Department of Surgery, Tokyo Rosai Hospital, Tokyo, Japan
4. The Department of Anesthesiology, Minami Machida Hospital, Machida, Tokyo, Japan
5. The Department of Thoracic and Cardiovascular Surgery, Niigata University School of Medicine, Niigata, Niigata, Japan