1702 NEPHROLITHOMETRY: A NOVEL SURGICAL CLASSIFICATION SYSTEM FOR RENAL STONES

Abstract

You have accessJournal of UrologyStone Disease: New Technology/SWL, Ureteroscopic or Percutaneous Stone Removal II1 Apr 20121702 NEPHROLITHOMETRY: A NOVEL SURGICAL CLASSIFICATION SYSTEM FOR RENAL STONES Zhamshid Okhunov, Martin Lesser, Justin Friedlander, Brian Duty, Arvin George, Arun Shrinivasan, Arthur Smith, and Zeph Okeke Zhamshid OkhunovZhamshid Okhunov New Hyde Park, NY More articles by this author , Martin LesserMartin Lesser New Hyde Park, NY More articles by this author , Justin FriedlanderJustin Friedlander New Hyde Park, NY More articles by this author , Brian DutyBrian Duty New Hyde Park, NY More articles by this author , Arvin GeorgeArvin George New Hyde Park, NY More articles by this author , Arun ShrinivasanArun Shrinivasan New Hyde Park, NY More articles by this author , Arthur SmithArthur Smith New Hyde Park, NY More articles by this author , and Zeph OkekeZeph Okeke New Hyde Park, NY More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1639AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Percutaneous nephrolithotomy (PCNL) is the minimally invasive treatment modality for complex kidney calculi. Instruments currently available to predict PCNL outcomes are cumbersome and of limited clinical utility. We proposed a novel standardized scoring system (SS) to predict outcomes of PCNL. The SS was previously validated with 52 patients undergoing PCNL and was found to be predictive of stone free rates (SFR) and radiation time (RT). In this study we evaluated the predictive value of each variable included in the SS in a larger cohort of patients who underwent PCNL. METHODS Five reproducible variables available from preoperative non-contrast computed tomography (CT) were measured, including stone volume (SV), stone density (SD), number of involved calyces, presence of hydronephrosis, and skin-to-stone distance (SSD). Scoring for each variable is outlined in Table 1. Comparisons of categories were made using the Wilcoxon rank sum test or Kruskal-Wallis test. Logistic regression was used to measure the association between variables. Table 1. Nephrolithometry scoring system. Variables/Scores 1 2 3 Stone volume (mm2) ≤225 225-900 >900 Stone density (HU) >900 >900 Hydronephrosis No/mild Severe Skin to stone distance (mm) ≤115 >115 Number of calyces Pelvis only, or 1 calyx involved Pelvis + >2 calyces Staghorn RESULTS A total of 137 patients were included. Demographic, clinical, and operative data are included in Table 2. SFR after first procedure was 80%. There were 18 (13.3%) complications. The most frequent complications were sepsis and bleeding. In a model predicting SFR, SV (p<0.0001), calyces (p<0.0001), greater number of calyces or staghorn calculi (SC) (p<0.0001), and pelvis involvement (p<0.004) were individually significantly associated with SFR. In a multivariable model, only SV and calyces were associated with SFR (p<0.0001). In a model predicting complications, SV (p<0.018) and SC (p<0.0318) were associated with complications. In a multivariate analysis, only SV was associated with complications (p=0.003). Table 2. Demographic, clinical, and operative data Gender (male/female) 74/63 Hydronephrosis (yes/no) 55/82 Position (prone/supine) 130/7 Mean (Range) Age (years) 55(16-77) BMI (kg/m2) 30 (15-48) Stone density (HU) 950(236-2345) Skin to stone distance (mm) 117 Operative time (minutes) 97.5(50-180) Estimated blood loss (ml) 230(50-400) Fluoroscopy time (minutes) 6.10(1.5-23.5) Length of stay (days) 2.9(2-10) Number (%) Complications 18(13.3) Stone free rate 80% CONCLUSIONS Nephrolithometry score can be used to successfully predict success of PCNL. Reproducible, standardized parameters obtained from CT can be used for preoperative patient counseling, surgical planning and for evaluation of surgical outcomes across institutions within the medical literature. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e687 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Zhamshid Okhunov New Hyde Park, NY More articles by this author Martin Lesser New Hyde Park, NY More articles by this author Justin Friedlander New Hyde Park, NY More articles by this author Brian Duty New Hyde Park, NY More articles by this author Arvin George New Hyde Park, NY More articles by this author Arun Shrinivasan New Hyde Park, NY More articles by this author Arthur Smith New Hyde Park, NY More articles by this author Zeph Okeke New Hyde Park, NY More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...