1. Department of Medicine and Gastroenterology, Gemeinschaftskrankenhaus Bonn, Academic Teaching Hospital, University of Bonn, Bonn, Germany
2. Institute of Medical Biometry, Informatics and Epidemiology (IMBIE), Faculty of Medicine, University of Bonn, Bonn, Germany
3. Department of Medicine/Gastroenterology, Evangelisches Diakoniekrankenhaus Freiburg, Freiburg, Germany
4. Department of Endoscopy, Saku Central Hospital Advanced Care Center, Nagano, Japan
5. Division of Research and Development for Minimally Invasive Treatment, Cancer Center, Keio University School of Medicine, Tokyo, Japan