[1] Yokohama City Univ, Grad Sch Med, Dept Gastroenterol Surg, Yokohama, Kanagawa, Japan
[2] Nara Med Univ, Dept Surg, Kashihara, Nara, Japan
[3] Mie Univ, Dept Hepatobiliary Pancreat & Transplant Surg, Grad Sch Med, Tsu, Mie, Japan
[4] Tokyo Metropolitan Canc & Infect Dis Ctr, Dept Surg, Komagorne Hosp, Bunkyo Ku, Tokyo, Japan
[5] Hokkaido Univ, Fac Med, Dept Gastroenterol Surg 2, Sapporo, Hokkaido, Japan
[6] Niigata Prefectural Cent Hosp, Dept Surg, Joetsu, Japan
[7] Nagaoka Chuo Gen Hosp, Dept Surg, Nagaoka, Niigata, Japan
[8] Hamamatsu Univ Sch Med, Dept Surg, Hamamatsu, Shizuoka, Japan
[9] Kansai Rosai Hosp, Dept Surg, Amagasaki, Hyogo, Japan
[10] Gifu Univ, Grad Sch Med, Dept Surg Oncol, Gifu, Japan
[11] Shiga Univ Med Sci, Dept Surg, Otsu, Shiga, Japan
[12] Kimitsu Chuo Hosp, Dept Surg, Kisarazu City, Japan
[13] Akita Univ, Dept Gastroenterol Surg, Grad Sch Med, Akita, Japan
[14] Iwakuni Med Ctr, Dept Surg, Iwakuni City, Japan
[15] Bell Land Gen Hosp, Dept Surg, Sakai, Osaka, Japan
[16] Okayama Saiseikai Gen Hosp, Dept Surg, Okayama, Japan
[17] Kagoshima Univ, Grad Sch Med & Dent Sci, Dept Digest Surg Breast & Thyroid Surg, Kagoshima, Japan
[18] Ibaraki Cent Hosp, Dept Surg, Kasama, Ibaraki, Japan
[19] Kumamoto Univ, Dept Gastroenterol Surg, Kumamoto, Japan
[20] Japanese Red Cross Kumamoto Hosp, Dept Surg, Kumamoto, Japan
[21] Jichi Med Univ, Saitama Med Ctr, Dept Surg, Sitama, Japan
[22] Wakayama Med Univ, Dept Surg 2, Wakayama, Japan
[23] Tokyo Womens Med Univ, Inst Gastroenterol, Dept Surg, Tokyo, Japan