[1] Univ Saarland, Dept Urol, Homburg, Germany
[2] Johanniter Krankenhaus Genthin Stendal gGmbH, Stendal, Germany
[3] Klinikum Hohe Warte Bayreuth, Bayreuth, Germany
[4] Hosp Kassel, Kassel, Germany
[5] HELIOS Klinikum Wuppertal GmbH, Wuppertal, Germany
[6] Univ Dusseldorf, Dept Urol, Dusseldorf, Germany
[7] Krankenhaus NW Frankfurt, Frankfurt, Germany
[8] Klinikum Osnabrueck, Osnabruck, Germany
[9] Univ Hosp Marburg, Marburg, Germany
[10] Zaans Med Zentrum, Zaandam, Netherlands
[11] Tech Univ Munich, Rechts Isar Med Ctr, Dept Urol, D-80290 Munich, Germany
[12] Saarland Univ Hosp, Homburg, Germany