1 Department of Surgery, University Hospital of Heidelberg, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany.
2 Interdisciplinary Endoscopic Center, University Hospital of Heidelberg, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany.
3 Department of Surgery, University Hospital of Heidelberg, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany. BeatPeter.Mueller@med.uni-heidelberg.de.