[1] Tech Univ Munich, Klinikum Rechts Isar, Dept Urol, Munich, Germany
[2] Tech Univ, Urol, Munich, Germany
[3] Univ Ulm, Ulm, Germany
[4] Univ Dusseldorf, Urol, Dusseldorf, Germany
[5] Hannover Med Sch, Urol, Hannover, Germany
[6] Heidelberg Univ, Urol, Heidelberg, Germany