1 Department of Gastroenterological Surgery, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-Cho, Kita-Ku, Okayama, 700-8558, Japan. y.kakiuchi@s.okayama-u.ac.jp.
2 Department of Gastroenterological Surgery, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-Cho, Kita-Ku, Okayama, 700-8558, Japan.
3 Department of Surgery, Tsuyama Chuo Hospital, 1756 Kawasaki, Tsuyama City, Okayama, 708-0841, Japan.