[1] Fdn Policlin Univ A Gemelli, Digest Endoscopy Unit, IRCCS, Rome, Italy
[2] Univ Cattolica Sacro Cuore, Ctr Endoscop Res Therapeut & Training CERTT, Rome, Italy
[3] Royal Free NHS Fdn Trust, UCL Inst Liver & Digest Hlth, Royal Free Unit Endoscopy, London, England
[4] Royal Free NHS Fdn Trust, UCL Inst Liver & Digest Hlth, Ctr Gastroenterol, London, England
[5] Imperial Coll London, St Marks Hosp & Acad Inst, Wolfson Unit Endoscopy, London HA1 3UJ, England
[6] Sorbonne Univ, St Antoine Hosp, APHP, Ctr Digest Endoscopy, Paris, France
[7] Univ Southern Denmark SDU, Dept Clin Res, Odense, Denmark
[8] Univ Bologna, Dept Med & Surg Sci, Gastroenterol Unit, IRCCS Azienda Osped Univ Bologna, Bologna, Italy
[9] Valduce Hosp, Gastroenterol Unit, Como, Italy
[10] Erasmus MC Univ, Dept Gastroenterol & Hepatol, Med Ctr, Rotterdam, Netherlands