[1] Hacettepe Univ, Dept Urol, Ankara, Turkey
[2] Univ Wurzburg, Dept Urol & Pediat Urol, Wurzburg, Germany
[3] Univ Hosp Ghent, Dept Urol, Ghent, Belgium
[4] Charles Univ Prague, Gen Univ Hosp, Dept Urol, Prague, Czech Republic
[5] Charles Univ Prague, Fac Med 1, Prague, Czech Republic
[6] Univ Groningen, Univ Med Ctr Groningen, Dept Urol, NL-9713 AV Groningen, Netherlands
[7] Med Univ Innsbruck, Dept Pediat Urol, Innsbruck, Austria
[8] Johannes Gutenberg Univ Mainz, Dept Urol, Mainz, Germany