EAU 2018: The Guy’s Stone Score, STONE Nephrolithometry, CROES Nomogram and S-ReSC Score

Copenhagen, Denmark (UroToday.com) Dr. Bibi, clinical urologist from the Hospital La Rabta in Tunis, Tunisia, presented his research study on the various nephrolithometry scores that are commonly used to classify stone burden in patients. The different classifications Dr. Bibi and his team explored were Guy’s stone score (GSS), S.T.O.N.E. score, CROES score, and S-ReSC score to compare predictive accuracy of stone-free rate (SFR) and complications after percutaneous nephrolithotomy (PCNL). 

In this study, a retrospective analysis of patients who had previously underwent PCNL between 2013 and 2016. Surgical outcomes and imaging data of preoperative computed tomography (CT) scans were reviewed to determine scores for the four aforementioned predictive classifications. These predictive systems use surgical intervention, stone burden, location, and multiplicity in order to quantify a symptom score of potential complications. Following surgical treatment, patients with residual fragments less than 4 mm were considered stone free. 

Following retrospective data collection, 157 procedures were identified. Fifty-nine percent of these patients were considered stone free following PCNL with a complication rate of 22% based on the Clavien-Dindo classification system. Of the four scoring systems, the CROES nomogram was the only classification type that was able to significantly predict stone free status and complications after PCNL. The remaining three systems were able to only produce significant predictions for stone free status alone. In regard to complication rates and surgical success based on stone location, it was found that upper calyceal stones had a significantly high amount of residual fragments and complications. 

Dr. Bibi concluded his presentation by informing the audience of the CROES nomogram’s efficacy in preoperatively predicting stone-free and complication rates. The CROES system also was the only grading system that additionally assessed the caseload and experience of the attending surgeon which may be indicative of the successes it saw in this study. 

Presented by: Bibi M. , Sellami A. , Ouanes Y. , Chaker K. , Ben Rhouma S. , Nouira Y.

Author Information: Hospital La Rabta, Dept. of Urology, Tunis, Tunisia 

Written by: Zachary Valley MD, Department of Urology, University of California-Irvine at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark