1 Department of General, Visceral, and Thoracic Surgery, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
2 Medical Faculty, Technische Universität Dresden, Dresden, Germany.
3 Department of Anesthesia and Intensive Care Medicine, St Elisabethen-Klinikum Ravensburg, Academic Teaching Hospital, University of Ulm, Ravensburg, Germany.
4 Department of General, Visceral, and Thoracic Surgery, St Elisabethen-Klinikum Ravensburg, Academic Teaching Hospital, University of Ulm, Ravensburg, Germany.