[1] Jichi Med Univ, Dept Surg, Div Gastroenterol Gen & Transplant Surg, 3311-1 Yakushiji, Shimotsuke, Tochigi 3290498, Japan
[2] Juntendo Univ, Fac Med, Dept Coloproctol Surg, Tokyo, Japan
[3] Dokkyo Med Univ, Dept Surg Oncol, Shimotsuga, Tochigi 3210293, Japan
[4] Yokohama City Univ, Med Ctr, Gastroenterol Ctr, Dept Surg, Yokohama, Japan
[5] Natl Hosp Org Shikoku Canc Ctr, Gastroenterol Surg, Matsuyama, Japan
[6] Oita Univ, Fac Med, Gastroenterol & Pediat Surg, Oita, Japan
[7] NTT East Corp, Kanto Med Ctr, Dept Cardiovasc Surg, Tokyo 1418625, Japan
[8] Tokai Univ Hosp, Dept Digest Surg, Isehara, Japan
[9] Kitasato Univ, Kitasato Inst Hosp, Dept Surg, Tokyo, Japan
[10] Osaka Red Cross Hosp, Dept Surg, Osaka, Japan
[11] Kitasato Univ, Dept Lower Gastrointestinal Surg, Sch Med, Sagamihara, Japan