[1] Teikyo Univ, Sch Med, Dept Surg, Itabashi Ku, Tokyo 1738605, Japan
[2] Sapporo Med Univ, Grad Sch Med, Dept Surg Oncol & Gastroenterol Surg, Sapporo, Hokkaido, Japan
[3] Nagoya Univ, Grad Sch Med, Dept Emergency & Crit Care Med, Nagoya, Aichi 4648601, Japan
[4] Int Univ Hlth & Welf, Clin Res Ctr, Kaken Hosp, Dept Hemodialysis & Surg, Chiba, Japan
[5] Kyoto Univ, Grad Sch Med, Dept Healthcare Econ & Qual Management, Kyoto, Japan
[6] Kumamoto Reg Med Ctr, Dept Surg, Kumamoto, Japan
[7] Natl Hosp Org, Sendai Med Ctr, Dept Surg, Sendai, Miyagi, Japan
[8] Mie Univ, Grad Sch Med, Dept Hepatobiliary Pancreat & Transplant Surg, Tsu, Mie, Japan
[9] Kanazawa Univ, Grad Sch Med Sci, Dept Radiol, Kanazawa, Ishikawa, Japan
[10] Yokohama City Univ, Med Ctr, Crit Care & Emergency Ctr, Yokohama, Kanagawa 232, Japan
[11] Tohoku Univ, Grad Sch Med, Div Gastroenterol, Sendai, Miyagi 980, Japan
[12] Nagoya Daini Hosp, Japanese Red Cross Soc, Nagoya, Aichi, Japan
[13] Ogaki Municipal Hosp, Dept Gastroenterol, Ogaki, Japan
[14] Kyoto Univ, Sch Publ Hlth, Dept Hlth Informat, Kyoto, Japan
[15] Univ Tokyo, Dept Radiol, Tokyo, Japan
[16] Kyushu Univ, Grad Sch Med Sci, Dept Surg & Oncol, Fukuoka 812, Japan