1. Department of Plastic Surgery, Hand Surgery and Burn Center, Faculty of Medicine, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany
2. Department of General, Visceral and Transplant Surgery, Faculty of Medicine, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany
3. Department of Obstetrics and Gynecology, Faculty of Medicine, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany
4. Department of Plastic and Reconstructive Surgery, Hand Surgery and Burn Care Center, Cologne-Merheim Medical Center, University of Witten/Herdecke, Ostmerheimer Straße 200, 51109 Cologne, Germany