1. Department of Urology, Johannes Gutenberg University, School of Medicine, Mainz
2. Department of Urology and Pediatric Urology, University of Witten/Herdecke, School of Medicine, Klinikum Wuppertal GmbH, Wuppertal
3. Department of Urology, Rhein.-Friedrichs-Wilhelms University, School of Medicine, Bonn, Germany