[1] Kyoto Univ, Dept Surg, Grad Sch Med, Kyoto, Japan
[2] Natl Hosp Org Kyoto Med Ctr, Dept Surg, Kyoto, Japan
[3] Kyoto Katsura Hosp, Dept Surg, Kyoto, Japan
[4] Shiga Gen Hosp, Dept Surg, Morinomiya, Shiga, Japan
[5] Tenri Hosp, Dept Gastrointestinal Surg, Tenri, Nara, Japan
[6] Osaka Red Cross Hosp, Dept Surg, Osaka, Japan
[7] Kobe City Med Ctr Gen Hosp, Dept Surg, Kobe, Hyogo, Japan
[8] Kitano Hosp, Dept Surg, Osaka, Japan
[9] Shimane Prefectural Cent Hosp, Dept Surg, Izumo, Shimane, Japan
[10] Kyoto Univ, Dept Biomed Stat & Bioinformat, Grad Sch Med, Kyoto, Japan