Comparison between retrograde intrarenal surgery and extracorporeal shock wave lithotripsy in the treatment of lower pole kidney stones up to 15 mm. Prospective, randomized study

Introduction: Extracorporeal Shock Wave Lithotripsy (ESWL) is currently the recommended treatment for intra-renal calculi smaller than 2 cm. However the low Stone Free, Rate (SFR) in lower pole calculi gives rise to new techniques, such us retrograde intrarenal surgery (RIRS), for improve the surgery outcomes. Objective: To compare the efficacy of a treatment with ESWL with RIRS, in terms of SFR after surgery, in patients with kidney stones up to 15 mm in the lower pole. Material and methods: A prospective study was carried out in order to assess the results of ESWL and RIRS in patients with lower pole stones less than 15mm. Among a total of 55 patients, 31 were underwent to ESWL (Group 1) and the remaining 24 to RIRS (Group 2). Clinical data recorded, including general characteristics of each patient, were: calculi size, side, operative time, complications according to Clavien scale, SFR and the presence of residual fragments at 2 months post-treatment assessed by a CT scan. STATA 11 was used to perform the statistical analysis. Results: There were no differences for general descriptors among groups with the exception of a significantly longer operative time for RIRS. The rates of SFR and residual fragments lesser than 3 mm. were lower in the RIRS group than in ESWL ones. RIRS also showed a lower rate of clinically significant fragments (0% vs 42.3%. P<.05). In the subgroup of patients with stones between 10/15 mm RIRS showed higher SFR (75% vs. 41.2%) and a lower rate of stones > 3 mm (0% vs. 58.8%), being statistically significant (P<.05). Clavien III or higher complications were not reported in any of the groups. Conclusions: In the treatment of lower pole stone RIRS has the same results than ESWL in terms of SFR. Regarding absence of a clinically significant residual fragment, RIRS was superior to ESWL. A bigger sample size is required in order to confirm this results. (C) 2014 AEU. Published by Elsevier Espana, S.L.U. All rights reserved.