[1] Heidelberg Univ, Dept Gen Surg, Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany
[2] Boston Gen Hosp, Dept Surg, Boston, MA USA
[3] Glasgow Royal Infirm, Lister Dept Surg, Glasgow, Lanark, Scotland
[4] Univ Verona, Policlin Borgo Roma, Verona, Italy
[5] Stadt Klinikum Luneburg, Med Klin, Luneburg, Germany
[6] Mayo Clin & Mayo Fdn, Dept Gastroenterol, Rochester, MN USA
[7] Brigham & Womens Hosp, Dept Gastroenterol, Boston, MA USA
[8] Univ Pittsburgh, Dept Med, Pittsburgh, PA USA
[9] Agia Olga Hosp, Dept Surg, Athens, Greece
[10] Univ Cincinnati, Dept Med, Cincinnati, OH USA
[11] Osaka City Univ, Sch Med, Dept Surg 1, Osaka, Japan
[12] Univ Liverpool, Dept Surg, Liverpool, Merseyside, England
[13] Mater Misericordiae Univ Hosp, Dept Surg, Dublin, Ireland