1. Center for Minimally Invasive and Robotic Urology, Augusta Hospital Bochum, Witten/Herdecke University, Bochum, Germany
2. Department of Urology, Pediatric Urology and Urologic Oncology, St. Antonius Hospital Gronau, Gronau, Germany
3. Department of Urology, Saarland University, Homburg/Saar, Germany
4. Department of Urology, University of Leipzig, Leipzig, Germany