Evaluation and comparison of scoring systems for predicting stone-free status after flexible ureteroscopy for renal and ureteral stones

• Published in: PloS one Vol. 15; no. 8; p. e0237068
• Main Authors: Richard, François, Marguin, Jonathan, Frontczak, Alexandre, Barkatz, Johann, Balssa, Loic, Bernardini, Stephane, Chabannes, Eric, Guichard, Guillaume, Bittard, Hugues, Kleinclauss, Francois
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 06.08.2020; Public Library of Science (PLoS)
• Subjects: Biology and Life Sciences; Care and treatment; Holmium; Hospitals; Kidneys; Laser surgery; Lithiasis; Lithotripsy; Mathematical analysis; Medicine and Health Sciences; Nomograms; Nomographs; Patient outcomes; Patients; People and Places; Performance evaluation; Research and Analysis Methods; Semiconductor lasers; Software; Stone; Supervision; Ureteroscopy; Urinary stones; Urology; Variables; YAG lasers; France; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0237068

To evaluate four predictive scores for stone-free rate (SFR) after flexible ureterorenoscopy (f-URS) with holmium-YAG laser fragmentation of renal and ureteral lithiasis. We carried out a retrospective analysis of 800 f-URS procedures performed in our institution between January 2009 and December 2016. For each procedure, a single surgeon calculated the following scores: S.T.O.N.E score; Resorlu Unsal Stone Score (RUSS); modified Seoul National University Renal Complexity (S-ReSC) score; and Ito's score. Overall SFR was 74.1%. Univariate analysis demonstrated that stone size (p<0.0001), stone volume (p<0.0001), stone number (p = 0.004), narrow lower pole infundibulopelvic angle (IPA) (p = 0.003) and lower pole location + IPA <45° (p = 0.011) were significantly associated with SFR. All scores differed between the stone-free and non-stone-free groups. Area under the curve of the receiving operator characteristics curve was calculated for each score: 0.617 [95%CI: 0.575-0.660] for the S.T.O.N.E score; 0.644 [95%CI: 0.609-0.680] for the RUSS; 0.651 [95%CI: 0.606-0.697] for the S-ReSC score; and 0.735 [95%CI: 0.692-0.777] for Ito's nomogram. All four scores were predictive of SFR after f-URS. Ito's score was the most sensitive. However, the performance of all scores in this analysis was lower than in developmental studies.