1. Department of Surgery, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
2. Department of Vascular Surgery, Saiseikai Central Hospital, Tokyo, Japan
3. Department of Surgery, Keio University School of Medicine, Tokyo, Japan
4. Department of Surgery, Mito Red Cross Hospital, Ibaraki, Japan
5. Department of Surgery, Saitama Municipal Hospital, Saitama, Japan
6. Department of Vascular Surgery, Shizuoka Red Cross Hospital, Shizuoka, Japan
7. Department of Surgery, Tokyo Dental College Ichikawa General Hospital, Chiba, Japan
8. Department of Vascular Surgery, Saiseikai Yokohamashi Tobu Hospital, Kanagawa, Japan
9. Department of Surgery, Hiratsuka City Hospital, Kanagawa, Japan