ORIGINAL PAPER Percutaneous nephrolithotomy for the treatment of radiolucent renal stones in children: is it different opaque stone treatment? S ¸ enol Adanur • Tevfik Ziypak • Ahmet Ali Sancaktutar • Abdu ¨lkadir Tepeler • Berkan Res ¸orlu • Haluk So ¨ylemez • Mansur Dag ˘gu ¨lli • I ˙ sa O ¨ zbey • Ali U ¨ nsal Received: 12 June 2013 / Accepted: 26 September 2013 / Published online: 18 October 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract We aimed to evaluate the effectiveness of percutaneous nephrolithotomy (PNL), stone-free rates, and related complications in children with radiolucent renal stones. A total of 56 patients aged \ 16 years from four institutions were enrolled in our study. Asymptomatic, clinically insignificant residual fragments measuring \ 4 mm or a complete stone-free status was accepted as the criterion for clinical success. Complications were evaluated according to the modified Clavien classification. The mean age of the patients was 7.8 ± 4.5 years. The mean stone size was calculated as 24.07 ± 10.4 mm. The median operative and fluoroscopy times were 53.2 min (15–170 min) and 172.4 s (5–520 s), respectively. The success rate after PNL monotherapy was 87.4 %; the total success rate with shock wave lithotripsy used as an auxil- lary treatment method was detected as 94.6 %. The total complication rate was 19.6 % (11 patients). No adjacent organ injury was observed. All of the complications that occurred were minor according to the Clavien classification (Clavien Grades I–II). PNL can be applied to radiolucent pediatric renal stones in children with similar success, and complication rates as noted for radiopaque stones. Keywords Children Á Radiolucent stone Á Percutaneous nephrolithotomy Introduction Urolithiasis is a globally serious problem. The prevalence of this disease has demonstrated increments in both the adult and pediatric populations in the last quarter of the twentieth century [1]. A prevalence rate of 14.8 %, sup- ported by a nationwide epidemiological study performed in 1991, is accepted as indicative of an endemic status in Turkey [2]. Stone disease in the pediatric age group can be associ- ated with metabolic diseases, genetic diseases, geographic regions, socioeconomic conditions, drug exposure, infec- tion diseases, and other environmental factors with a high risk of recurrence [3]. Therefore, appropriate treatment methods should be selected for this age group. Minimally invasive procedures are the most important treatment modalities for this age group. The medical and surgical treatment of urolithiasis in children has evolved during the last two decades. Mini- mally invasive methods have developed rapidly, and have replaced open surgical treatment modalities for renal or ureteral stones. The first pediatric percutaneous nephroli- thotomy (PNL) series was performed in 1985 on seven pediatric patients with a median age of 14 years using adult-sized instruments [4]. Following the first reports of PNL procedures performed by Woodside on children, PNL S ¸ . Adanur (&) Á T. Ziypak Á I ˙ .O ¨ zbey Department of Urology, Medical Faculty, School of Medicine, Ataturk University, 25240 Erzurum, Turkey e-mail: s.adanur61@hotmail.com A. A. Sancaktutar Á H. So ¨ylemez Á M. Dag ˘gu ¨lli Department of Urology, Medical Faculty, Dicle University, Diyarbakır, Turkey A. Tepeler Department of Urology, Medical Faculty, Bezmialem Vakıf University, Istanbul, Turkey B. Res ¸orlu Department of Urology, Kecioren Training and Research Hospital, Ankara, Turkey A. U ¨ nsal Department of Urology, Gazi University, Ankara, Turkey 123 Urolithiasis (2014) 42:81–86 DOI 10.1007/s00240-013-0610-7