1 Department of General, Thoracic, Vascular and Transplantation Surgery, University of Rostock, Rostock, Germany, Erlangen, Germany.
2 Central Interdisciplinary Endoscopy Unit, Medical Faculty Mannheim, Heidelberg University, University Medical Center Mannheim, Mannheim, Germany, Erlangen, Germany.
3 Medical Clinic 1, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.