[1] Caritas Krankenhaus St Josef, Dept Surg, D-93053 Regensburg, Germany
[2] Krankenhaus Waldfriede, Dept Surg, Berlin, Germany
[3] Osped S Maria Angeli, Dept Surg, Pordenone, Italy
[4] Casa Cura San Pio X, Dept Surg, Milan, Italy
[5] St James Univ Hosp, Acad Surg Unit, Leeds LS9 7TF, W Yorkshire, England
[6] Southampton Gen Hosp, Dept Surg, Southampton SO9 4XY, Hants, England
[7] Bagatelle Maison de Sante, Dept Proctol, Talence, France
[8] Univ Hosp, Dept Digest Surg, Rouen, France
[9] Dept Surg, Notre Dame, Charleroi, Belgium
[10] Hosp Gen Valle Hebron, Dept Surg, Barcelona, Spain
[11] Kantonsspital, Dept Surg, St Gallen, Switzerland