[1] Odense Univ Hosp, Dept Surg, Svendborg, Denmark
[2] Univ Southern Denmark, Dept Clin Res, Odense, Denmark
[3] Catholic Univ, Digest Endoscopy Unit, Rome, Italy
[4] Poliambulanza Fdn, Digest Endoscopy Unit, Brescia, Italy
[5] Complejo Hosp Navarra, Dept Gastroenterol, Pamplona, Spain
[6] Ninewells Hosp & Med Sch, Dept Surg, Dundee, Scotland