1 Department of General and Visceral Surgery, Bodden-Kliniken Ribnitz-Damgarten, Sandhufe 2, 18311, Ribnitz-Damgarten, Germany. r.wiessner@bodden-kliniken.de.
2 Department of General, Visceral, Vascular and Transplantation Surgery, University of Rostock, Rostock, Germany.