[1] AGAPLESION Markus Krankenhaus, Dept Surg, Frankfurt, Germany
[2] Tech Univ Munich, Klinikum Rechts Isar, Dept Gastroenterol, D-80290 Munich, Germany
[3] Univ Krankenhaus Eppendorf, Dept Endoscopy, D-20246 Hamburg, Germany
[4] Univ Barcelona, Dept Gastroenterol, Hosp Clin, Barcelona, Spain
[5] Israelit Krankenhaus, Dept Surg, Hamburg, Germany
[6] Univ Barcelona, Dept Surg, Hosp Clin, Barcelona, Spain