[1] Fdn Policlin Univ Agostino Gemelli IRCCS, Digest Endoscopy Unit, I-00168 Rome, Italy
[2] IHU Strasbourg, 1 Pl Hop, F-67091 Strasbourg, France
[3] Univ Cattolica Sacro Cuore Roma, Ctr Endoscop Res Therapeut & Training CERTT, Rome, Italy
[4] Univ Pavia, Fdn IRCCS San Matteo Hosp, Dept Internal Med 1, Pavia, Italy
[5] Univ Pavia, Gastroenterol Unit, Ist Clin Maugeri, Pavia, Italy
[6] Fdn Policlin Univ Agostino Gemelli IRCCS, Digest Endoscopy Unit, Rome, Italy
[7] IHU Strasbourg, Inst Image Guided Surg, Strasbourg, France