1814 FACTORS INFLUENCING THE SUCCESSFUL SHOCK WAVE LITHOTRIPSY (SWL) TREATMENT OF RENAL AND URETERIC STONES: TOWARDS A CLINICAL NOMOGRAM

Abstract

You have accessJournal of UrologyStone Disease: SWL, Ureteroscopic or Percutaneous Stone Removal III1 Apr 20101814 FACTORS INFLUENCING THE SUCCESSFUL SHOCK WAVE LITHOTRIPSY (SWL) TREATMENT OF RENAL AND URETERIC STONES: TOWARDS A CLINICAL NOMOGRAM Joshua D. Wiesenthal, Daniela Ghiculete, A. Andrew Ray, Steven Pace, R. John D'A. Honey, and Kenneth T. Pace Joshua D. WiesenthalJoshua D. Wiesenthal More articles by this author , Daniela GhiculeteDaniela Ghiculete More articles by this author , A. Andrew RayA. Andrew Ray More articles by this author , Steven PaceSteven Pace More articles by this author , R. John D'A. HoneyR. John D'A. Honey More articles by this author , and Kenneth T. PaceKenneth T. Pace More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1739AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Shock wave lithotripsy (SWL) is considered the first line treatment for the majority of patients with renal and ureteric calculi, with success rates for contemporary series varying from 60-90%. Although success is dependent on patient and stone-related factors there are few reliable algorithms predictive of SWL success. We conducted a retrospective analysis of patient and stone-related factors to determine their influence on the success of SWL and develop a comprehensive nomogram to predict SWL outcomes. METHODS Data from patients treated at the St. Michael's Hospital Lithotripsy Unit from May 2004 to June 2009 were reviewed. Analysis was restricted to those patients with a pre-treatment non-contrast CT scan conducted at our centre demonstrating a solitary renal or ureteric calculus < 20 mm in maximal diameter. Successful treatment of renal stones was defined as those patients who were stone free or had asymptomatic, clinically insignificant residual fragments < 4 mm in diameter three months after a single SWL treatment. Successful treatment of ureteric stones was defined as stone free 2-week post-SWL. Demographic, stone, patient, treatment and follow-up data were collected from a prospective database and review of CT and KUB imaging by two independent urologists and one radiologist. Data was analyzed with logistic regression, Chi square analysis and ANOVA where appropriate. RESULTS 422 patients (69.7% male) with a mean age of 51.4 years (SD 12.9) and mean BMI 27.0 kg/m2 (SD 4.9) were analyzed. Mean stone size was 78.9 mm2 (SD 77.3) for ureteral stones and 66.1 mm2 (SD 63.2) for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single treatment success rates for ureteral and renal stones were 62.3% and 68.8%, respectively. On univariate analysis, predictors of SWL success, regardless of stone location, were age (p=0.01), BMI (p=0.01), stone size (p<0.001), skin-to-stone distance (SSD; p<0.001), and CT attenuation (CTHU, p=0.003). On multivariate analysis, age > 60 (OR=0.60, p=0.011), stone size > 45 mm2 (OR=0.35, p<0.001), and SSD > 110 mm (OR=.49, p<0.001) remained significant predictors of outcome. CONCLUSIONS We have identified patient and stone parameters that can reliably predict SWL outcomes for both ureteral and renal stones. This data can be used by clinicians to facilitate optimal treatment-based decisions and provide patients with more accurate single-treatment success rates for SWL that are tailored to patient-specific situations. Toronto, Canada© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e704 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Joshua D. Wiesenthal More articles by this author Daniela Ghiculete More articles by this author A. Andrew Ray More articles by this author Steven Pace More articles by this author R. John D'A. Honey More articles by this author Kenneth T. Pace More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...