1. Department of Surgery, Osaka National Hospital, Osaka, Japan
2. Department of Surgery, Toyonaka Municipal Hospital, Toyonaka, Japan
3. Department of Surgery, Osaka Medical Centre for Cancer and Cardiovascular Disease, Osaka, Japan
4. Department of Surgery, Sakai Municipal Hospital, Sakai, Japan
5. Department of Surgery, Nippon Telegraph and Telephone Corporation West Osaka Hospital, Osaka, Japan
6. Department of Surgery, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Itami, Japan
7. Department of Surgery, Osaka University Medical School, Suita, Japan
8. Department of Surgery, Graduate School of Medicine and Engineering, Yamanashi University, Yamanashi, Japan