[1] Hiroshima Univ, Grad Sch Biomed & Hlth Sci, Dept Gastroenterol & Transplant Surg, Hiroshima, Japan
[2] Hiroshima Univ, Grad Sch Biomed & Hlth Sci, Dept Epidemiol Infect Dis Control & Prevent, Hiroshima, Japan
[3] Hiroshima City Asa Citizens Hosp, Dept Surg, Hiroshima, Japan
[4] Onomichi Gen Hosp, Dept Surg, Onomichi, Japan
[5] Natl Hosp Org Higashihiroshima Med Ctr, Dept Surg, Higashihiroshima, Japan
[6] Chugoku Rosai Hosp, Dept Surg, Kure, Japan
[7] Natl Hosp Org Hiroshima Nishi Med Ctr, Dept Surg, Otake, Japan