Affiliation: | (1) Department of Thoracic and Cardiovascular Surgery, Sapporo Medical University School of Medicine, South 1, West 16, Chuo-ku, Sapporo 060, Japan;(2) Department of Cardiovascular Surgery, Hokkaido Children's Hospital and Medical Center, 1-10-1 Zenibako, 047-02 Otaru, Japan;(3) Department of Surgery, Hokkaido Children's Hospital and Medical Center, 1-10-1 Zenibako, 047-02 Otaru, Japan |