[1] Haukeland Hosp, Dept Urol, Bergen, Norway
[2] Univ Bergen, Dept Clin Med, Bergen, Norway
[3] EAU YAU Urolithiasis Grp, Arnhem, Netherlands
[4] Univ Hosp Southampton, Dept Urol, Southampton, England
[5] Aristotle Univ Thessaloniki, Fac Hlth Sci, Sch Med, Dept Urol, Thessaloniki, Greece
[6] Father Muller Med Coll, Dept Urol, Mangalore, Karnataka, India
[7] Natl & Kapodistrian Univ Athens, Sismanogleio Gen Hosp, Dept Urol 2, Athens, Greece