1. The Centre for Therapeutic Endoscopy and Endoscopic Oncology, St Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
2. Hepato-Gastroenterology and Therapeutic Endoscopy Unit, 1st Division of Internal Medicine, Medical School of Ioannina, Ioannina, Greece
3. Division of Gastroenterology, Lenox Hill Hospital, New York, USA
4. The Royal London Hospital NHS Trust, Whitechapel, London, UK
5. Department of Epidemiology, Medical School of Ioannina, Ioannina, Greece