Renal Damage Risk Assessment in Vesicoureteral Reflux: A Pilot Study

Sunday, October 3, 2010: 8:15 AM
Yerba Buena Salon 9 (San Francisco Marriott Marquis)
Akanksha Mehta, M.D., Urology, Brown University Warren-Alpert School of Medicine, Providence, RI, Jason T. Machan, Ph.D., Bio-Medical Research, Brown University Warren-Alpert School of Medicine, Providence, RI and Anthony A. Caldamone, MD, Pediatric Urology, Brown University Warren-Alpert School of Medicine, Providence, RI

Purpose: Current literature provides evidence-based data for the following risk factors as risk variables for renal damage from VUR: age at presentation, type of UTI, presence of dysfunctional voiding, status of renal parenchyma, breakthrough pyelonephritis, and grade of VUR. Most studies assessing risk have focused on the risk of persistence of VUR, although renal damage is a more important determinant of VUR-related morbidity, and, therefore, a more clinically relevant end-point with respect to the decision for observation versus surgical intervention. We formulated a scoring system for the risk of renal damage from VUR, and applied it to current VUR patients, to assess the degree to which pediatric urologists follow renal risk-based recommendations in the management of VUR. Methods: A weighted scoring system was developed for factors that have been shown to influence the risk of renal damage in children with VUR. The overall score for each patient was calculated by adding the scores for each individual risk factor. This protocol was applied to 220 patients with VUR from nine pediatric urology practices, approximately half of whom had been followed non-operatively, and half of whom had been corrected. Generalized estimating equations with patients nested within their physicians were performed to test each risk factor as a predictor of surgical intervention as well as the overall score. Results: 112 patients underwent surgical intervention while 108 were managed non-operatively. Of all the factors studied, age at presentation, highest grade of reflux, upper tract status, and breakthrough pyelonephritis were statistically significant predictors of patients progressing to surgical intervention, while presenting UTI, dysfunctional voiding, and family compliance did not show a statistically significant difference between patients managed operatively and non-operatively. Briefly, patients with age<1 at presentation, grade IV-V VUR, abnormality of upper tracts on radiologic imaging, and more than one episode of breakthrough pyelonephritis were more likely to undergo surgical treatment. Conclusions: Of seven risk factors identified as risk variables for renal damage from VUR, age<1, high grade of reflux (grade IV-V), abnormal upper tract status, and breakthrough UTIs were associated with increased odds of patients undergoing surgical intervention for the management of VUR. Failure to see an association between the other risk variables and increased chance of surgical intervention may be either due to the lack of a true association, due to the design of our weighted scoring system, or because the distribution of patients within each risk category did not allow a statistically significant difference to be demonstrated. This risk scoring system could be an effective tool to follow VUR patients longitudinally.
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