[1] Hokkaido Univ, Grad Sch Med, Dept Surg Oncol, Kita Ku, Sapporo, Hokkaido 0608638, Japan
[2] Wakayama Med Univ, Sch Med, Dept Surg 2, Wakayama, Japan
[3] Tohoku Univ, Grad Sch Med, Dept Surg, Div Hepatobiliary Pancreat Surg, Sendai, Miyagi 980, Japan
[4] Kansai Med Univ, Dept Surg, Osaka, Japan
[5] Tokyo Womens Med Univ, Inst Gastroenterol, Dept Surg, Tokyo, Japan
[6] Hiroshima Univ, Grad Sch Biomed Sci, Dept Surg, Div Clin Med Sci, Hiroshima, Japan
[7] Kyoto Univ, Dept Hepatobiliary Pancreat Surg & Transplantat, Kyoto, Japan
[8] Fujita Hlth Univ, Sch Med, Dept Biliary Pancreat Surg, Aichi, Japan
[9] Kagoshima Univ, Dept Surg Oncol, Kagoshima 890, Japan
[10] Kanazawa Univ, Grad Sch Med Sci, Dept Surg Gastroenterol, Kanazawa, Ishikawa, Japan
[11] Teikyo Univ, Sch Med, Dept Surg, Japanese Soc Hepatobiliary Pancreat Surg, Tokyo 173, Japan