[1] Univ Hosp Geneva, Div Gastroenterol & Hepatol, Serv Gastroenterol & Hepatol, CH-1211 Geneva 14, Switzerland
[2] Med Ctr Postgrad Educ, Dept Gastroenterol & Hepatol, Warsaw, Poland
[3] M Sklodowska Curie Mem Canc Ctr, Dept Gastroenterol, Warsaw, Poland
[4] Inst Oncol, Warsaw, Poland
[5] Catholic Univ, Digest Endoscopy Unit, Rome, Italy
[6] Univ Copenhagen, Herlev Hosp, Dept Surg Gastroenterol, DK-1168 Copenhagen, Denmark
[7] Univ Copenhagen, Gentofte Hosp, DK-1168 Copenhagen, Denmark
[8] Paoli Calmettes Inst, Endoscop Unit, Marseilles, France
[9] Cannes Hosp, Endoscop Unit, Cannes, France
[10] Hop Prive Jean Mermoz, Dept Gastroenterol, Lyon, France
[11] Hosp Clin Barcelona, Dept Gastroenterol, Endoscopy Unit, ICMDM,IDIBAPS,CIBER Ehd, Barcelona, Spain
[12] Univ Alcala, Hosp Ramon, Div Gastroenterol, Madrid, Spain