[1] Tohoku Univ, Sch Med, Dept Surg, Aoba Ku, Sendai, Miyagi 9808574, Japan
[2] S Miyagi Med Ctr, Dept Surg, Ogawara, Miyagi 9891253, Japan
[3] Ichinoseki Hosp, Dept Surg, Ichinoseki, Iwate 0210884, Japan
[4] Tohoku Kosei Nenkin Hosp, Dept Surg, Miyagino Ku, Sendai, Miyagi 9830005, Japan
[5] Japanese Red Cross Sendai Hosp, Dept Surg, Tihaku Ku, Sendai, Miyagi 9820801, Japan
[6] Tohoku Rosai Hosp, Dept Surg, Aoba Ku, Sendai, Miyagi 9810911, Japan
[7] Fukushima Rosai Hosp, Dept Surg, Fukushima 9738403, Japan
[8] Mito Kyodo Gen Hosp, Dept Surg, Mito, Ibaraki 3100015, Japan
[9] Miyagi Canc Ctr, Dept Surg, Natori, Miyagi 9811239, Japan
[10] Mizusawa City Hosp, Dept Surg, Mizusawa, Iwate 0230053, Japan