1. Department of Plastic and Aesthetic Surgery, Hand Surgery, HELIOS Hospital Emil von Behring, Walterhöferstr. 11, 14165 Berlin, Germany
2. Desert Flower Center, Center of Colorectal and Pelvic Floor Surgery, Hospital Waldfriede, Argentinische Allee 40, 14163 Berlin, Germany
3. Department of Plastic and Hand Surgery, University of Freiburg Medical Centre, Medical Faculty of the University of Freiburg, Hugstetter Straße 55, 79106 Freiburg, Germany