[1] Kinki Univ, Sch Med, Dept Gastroenterol & Hepatol, Osaka 589, Japan
[2] Tokyo Med & Dent Univ, Grad Sch Med, Dept Hepatobiliary Pancreat Surg, Tokyo, Japan
[3] Keio Univ, Sch Med, Dept Pathol, Tokyo 160, Japan
[4] Univ Tokyo, Dept Gastroenterol, Grad Sch Med, Tokyo, Japan
[5] Univ Tokyo, Dept Surg, Grad Sch Med, Hepatobiliary Pancreat Surg Div, Tokyo, Japan
[6] Nihon Univ, Sch Med, Dept Digest Surg, Tokyo, Japan
[7] Kurume Univ, Sch Med, Dept Gastroenterol & Hepatol, Kurume, Fukuoka 830, Japan
[8] Kurume Univ, Med Ctr, Dept Gastroenterol, Kurume, Fukuoka 830, Japan
[9] Univ Tokushima, Dept Surg, Tokushima 770, Japan
[10] Ogaki Municipal Hosp, Dept Gastroenterol, Ogaki, Japan
[11] Kanazawa Univ, Sch Med, Dept Gastroenterol, Kanazawa, Ishikawa 920, Japan