[1] Tokyo Med Univ, Div Gastroenterol & Hepatol, Shinjuku Ku, Tokyo 1600023, Japan
[2] Tokyo Med Univ, Res & Dev Ctr Minimally Invas Therapies Hlth Prom, Shinjuku Ku, Tokyo 1608402, Japan
[3] Keio Univ, Inst Adv Biosci, Tsuruoka, Yamagata 9970052, Japan
[4] Tokyo Med Univ, Dept Surg 3, Shinjuku Ku, Tokyo 1600023, Japan
[5] Tokyo Med Univ, Hachioji Med Ctr, Dept Surg 4, Hachioji, Tokyo 1900998, Japan