1. Department of General Surgery, Luzern Canton Hospital, Spitalstrasse, 6000 Luzern 16, Switzerland
2. Intensive Care Unit, Luzern Canton Hospital, Spitalstrasse, 6000 Luzern 16, Switzerland
3. Department of Anesthesia, Luzern Canton Hospital, Spitalstrasse, 6000 Luzern 16, Switzerland
4. Department of Radiology, Luzern Canton Hospital, Spitalstrasse, 6000 Luzern 16, Switzerland