1. Department of Surgery, Iga City General Hospital, 831 Shijuku-cho, Iga, Mie 518-0823, Japan
2. Department of Gastrointestinal and Pediatric Surgery, Mie University Hospital, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
3. Department of Surgery, Wakaba Hospital, 28-13 Minami-Chuo, Tsu, Mie 514-0832, Japan