[1] Univ Amsterdam, AMC Univ Hosp, Dept Urol, NL-1100 DE Amsterdam, Netherlands
[2] Donauspital, Dept Urol & Androl, Vienna, Austria
[3] Sismanoglio Hosp, Athens Med Sch, Urol Dept 2, Athens, Greece
[4] Univ Copenhagen, Herlev Hosp, Dept Urol, Copenhagen, Denmark
[5] Univ Zaragoza, Hosp Miguel Servet, Dept Urol, Zaragoza, Spain
[6] UCL Royal Free & Univ Coll Med Sch, Inst Urol, London, England