You have accessJournal of UrologyStone Disease: SWL, Ureteroscopy or Percutaneous Stone Removal (I)1 Apr 20131532 PREDICTION OF SINGLE PROCEDURE SUCCESS RATE USING S.T.O.N.E. NEPHROLITHOMETRY SURGICAL CLASSIFICATION SYSTEM WITH STRICT CRITERIA FOR SURGICAL OUTCOME Arash Akhavein, Carl Henriksen, and Vincent G Bird Arash AkhaveinArash Akhavein Gainesville, FL More articles by this author , Carl HenriksenCarl Henriksen Gainesville, FL More articles by this author , and Vincent G BirdVincent G Bird Gainesville, FL More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.3022AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Percutaneous nephrostolithomy (PCNL) is a commonly employed surgical modality for treatment of large and complex urinary stones. Instruments for outcome prediction have limitations relating to clinical utility, ease of use, and lack of validation. The S.T.O.N.E. nephrolithometry scoring system was recently introduced by Okhunov et al as a more practical method. We evaluate this scoring system in a recent PCNL cohort using computerized tomography (CT) imaging with strict criteria for stone clearance as a measure of surgical outcome. METHODS We maintain an institutional review board approved prospective database of all patients undergoing stone surgery by a single surgeon. Inclusion criteria included primary PCNL and availability of pre- and post-operative CT imaging. Technique for PCNL involves percutaneous access at time of procedure and stone removal by means of both rigid and flexible nephroscopy. Repeat CT is done on post-operative day 1-14. Residual stone is scored as 0-2 mm, 3-4 mm, and >4 mm. Stone size, tract length, obstruction (hydronephrosis), number of calyces with stone, and essence (CT attenuation value) are recorded and scored as according to Okhunov et al. Statistical analysis was performed using t test for continuous variables and chi square testing for categorical covariates. Final score and stone free analysis was analyzed with logistic regression. RESULTS 117 patients were available for analysis. Table 1 summarizes the results. Gender distribution and mean age were 56 M vs 61 F and 56.7 yrs. Nephrolithometry score ranged from 6 to 12. Postoperative CT for residual stone showed 88 (75%) and 29 (25%) patients had 0-4 mm, and >4 mm residual stone respectively. There were 12 (10%) complications, most commonly fever. No patients required perioperative blood transfusion. Mean nephrolithometry score for residual stone 0-4 mm and >4 mm were 8.9 and 10.3 respectively (logistic regression p<0.0001). CONCLUSIONS With use of strict CT imaging criteria for assessment of residual stone status, the S.T.O.N.E. scoring system is reproducible and predictive of treatment success. Further investigation is required to both validate this model and to determine if other predictive parameters will improve it as a predictive model. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited ByLabadie K, Okhunov Z, Akhavein A, Moreira D, Moreno-Palacios J, del Junco M, Okeke Z, Bird V, Smith A and Landman J (2018) Evaluation and Comparison of Urolithiasis Scoring Systems Used in Percutaneous Kidney Stone SurgeryJournal of Urology, VOL. 193, NO. 1, (154-159), Online publication date: 1-Jan-2015. Volume 189Issue 4SApril 2013Page: e627-e628 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Arash Akhavein Gainesville, FL More articles by this author Carl Henriksen Gainesville, FL More articles by this author Vincent G Bird Gainesville, FL More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...