1 Endoscopy Unit, Gastroenterology Department, Hospital Universitario de Navarra, Navarrabiomed, Universidad Pública de Navarra, Pamplona, Spain.
2 Methodology Unit, Gastroenterology Department, Hospital Universitario de Navarra, Navarrabiomed, Universidad Pública de Navarra, Pamplona, Spain.
3 Gastrointestinal Endoscopy Research Unit, Gastroenterology Department, Hospital Universitario de Navarra, Navarrabiomed, Universidad Pública de Navarra, Pamplona, Spain.