Retrograde Intrarenal Surgery Monotherapy Versus Shock Wave Lithotripsy for Stones 10 to 20 mm in Preschool Children: A Prospective, Randomized Study Ibrahim A. Mokhless, Hussein M. Abdeldaeim,* Ashraf Saad and Abdel Rahman Zahran From the Urology Department, Alexandria University, Alexandria, Egypt Purpose: We compared the outcome of retrograde intrarenal surgery mono- therapy vs shock wave lithotripsy for stones 10 to 20 mm in preschool children. Materials and Methods: This prospective study included 60 children with a mean Æ SD age of 2.4 Æ 1.3 years. Patients were randomly divided into 2 groups. Group 1 underwent shock wave lithotripsy and group 2 underwent retrograde intrarenal surgery as monotherapy. Retrograde intrarenal surgery was started using a 7.5Fr semirigid ureteroscope (StorzÒ) and the holmium laser, and completed by the Flex XÔ2 flexible ureterorenoscope. A ureteral access sheath was not used and only hydrodilatation was performed. Patients were evaluated preoperatively by ultrasound and plain abdominopelvic x-ray. Followup was 3 months. Results: The stone-free rate after a single session treatment was 70% and 86.6% in groups 1 and 2, respectively. Mean operative time was 27.9 Æ 3.5 and 40 Æ 7.8 minutes, mean fluoroscopy exposure time was 60 Æ 42 and 50 Æ 35 seconds, and mean hospital stay was 6 Æ 2 and 12 Æ 8 hours, respectively. No major compli- cation occurred in either group and no child in either group received blood transfusion. Nine group 1 patients needed a second shock wave lithotripsy ses- sion, of whom 2 required a third session. At 3 months the overall stone-free rate was 93.3% and 96.6% in groups 1 and 2, respectively. Conclusions: Retrograde intrarenal surgery is an option for treating medium sized renal stones in preschool children with results comparable to those of shock wave lithotripsy and a safe short-term outcome. Key Words: kidney; calculi; lithotripsy; lithotripsy, laser; endoscopes SHOCK wave lithotripsy has revolu- tionized the management of upper urinary tract stones in children. It is now considered the procedure of choice by many pediatric urologists for renal stones less than 2 cm. 1,2 However, the success rate of SWL decreases significantly with an in- crease in stone size and the need for additional sessions also increases as stone size increases. 3,4 Today managing renal calculi in children by endourological techniques is possible with the availability of smaller equipment. 2 RIRS is now performed at many centers in cases that were previously managed by SWL or percutaneous nephrolitho- tripsy. 5 The technique seems feasible but more data are needed for com- parison with the results of other treatment modalities for stones in infants and preschool children. We compared the outcome of RIRS monotherapy vs SWL for stones 10 to 20 mm in preschool children. Abbreviations and Acronyms ESWL ¼ extracorporeal SWL JJ ¼ Double-JÒ RIRS ¼ retrograde intrarenal surgery SWL ¼ shock wave lithotripsy Accepted for publication August 26, 2013. Study received local ethics committee approval. * Correspondence: Urology Department, Alex- andria University, Alexandria, Egypt (telephone: 00201223421863; FAX: 002034860029; e-mail: h_abdeldaeim@hotmail.com ). 1496 j www.jurology.com 0022-5347/14/1915-1496/0 THE JOURNAL OF UROLOGY ® © 2014 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION AND RESEARCH,INC. http://dx.doi.org/10.1016/j.juro.2013.08.079 Vol. 191, 1496-1500, May 2014 Printed in U.S.A.