[1] Keio Univ, Dept Surg, Sch Med, Tokyo, Japan
[2] Kumamoto Univ, Dept Pediat Surg & Transplantat, Sch Med, Kumamoto, Japan
[3] Int Univ Hlth & Welf, Dept Digest Ctr, Mita Hosp, Tokyo, Japan
[4] Keio Univ, Dept Pathol, Sch Med, Tokyo, Japan
[5] Int Univ Hlth & Welf, Dept Gastrointestinal Surg, Chiba, Japan
[6] Keio Univ, Dept Pediat Surg, Sch Med, Tokyo, Japan