MP54-14 A PREOPERATIVE PREDICTIVE SCORE FOR URIC ACID KIDNEY STONES

Abstract

You have accessJournal of UrologyStone Disease: Epidemiology & Evaluation II (MP54)1 Sep 2021MP54-14 A PREOPERATIVE PREDICTIVE SCORE FOR URIC ACID KIDNEY STONES Mario Basulto-Martínez, Silvia Proietti, Maria Pia Pavia, Luis Rico, Yuyi Yeow, Juan Pablo Flores-Tapia, Antonio Esqueda-Mendoza, Franco Gaboardi, and Guido Giusti Mario Basulto-MartínezMario Basulto-Martínez More articles by this author , Silvia ProiettiSilvia Proietti More articles by this author , Maria Pia PaviaMaria Pia Pavia More articles by this author , Luis RicoLuis Rico More articles by this author , Yuyi YeowYuyi Yeow More articles by this author , Juan Pablo Flores-TapiaJuan Pablo Flores-Tapia More articles by this author , Antonio Esqueda-MendozaAntonio Esqueda-Mendoza More articles by this author , Franco GaboardiFranco Gaboardi More articles by this author , and Guido GiustiGuido Giusti More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002084.14AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The stone analysis composition is paramount for patients' follow-up and prevention but is only available after surgery. Uric acid calculi (UAC) account for up to 15%. Recent evidence points that UAC <2 cm can be first treated by alkalinizing therapy with good results. Furthermore, alkalinizing larger UAC, may decrease the stone burden and therefore improve the chance of achieving a stone-free rate in a further surgical procedure. We aimed to create a preoperative score for predicting UAC. METHODS: Patients who underwent kidney stones surgery from to March 2018 to March 2019 with available preoperative abdominal non-contrast computed tomography (CT) scan and stone analysis composition were included and clinical data was obtained. Mean Hounsfield Units (HU) and standard deviation from the stone density (SDSD) were calculated from CT scans, as computed by growing Regions of Interest using OsiriX DICOM viewer Software. The stone analysis composition was carried out by infrared spectroscopy. Stones >80% of uric acid weredichotomized as UAC or otherwise as non-uric acid calculi (NUAC). Categorical data were compared by X2 test, continuous data by the U-Mann-Whitney test, and logistic regression test was performed for categorical data and UAC. ROC curve analysis was conducted for the HU, SDSD, and UAC, and cutoff points were set. Using data associated with UAC, a score was constructed and tested. A p<0.05 was considered statistically significant. RESULTS: A total of 92 patients were included with a median age of 55 (46–65) years and 53.3% were female. The stone composition was 67% calcium-containing, 14% uric acid, 10 % infective, 7.7% cystine, and 1% other stones. HU was significantly lower in UAC group [400 (304 – 565) vs 689 (521 – 689), p<0.001] as well as SDSD [152.2 (125.9–319.4) vs 358.1 (267.6–446.5), p<0.001]. T2D and HTN were associated with UAC (p=0.007 and p=0.041, respectively)ROC curves for UAC and mean HU showed an area under the curve (AUC) of 0.851, [Coefficient Interval (CI) 95% 0.73–0.97], p<0.001. As for SDSD, AUC was 0.808 (CI95%, 0.67–0.94). Cutoff points were selected according to the best specificity and sensitivity. Thus, a score ranging from 0-4 was created based upon variables significantly related to UAC, which were HTN, T2D, mean HU <400, and SDSD <350. Score of 0, 1, 2, 3, and 4, resulted in UAC proportion of 0%, 6.7%, 25%, 66.7%, and 100%. The AUC for the score was 0.86 (CI 95% 0.77–0.96) p<0.001. Patients with a score of 3-4 had 71.4% of UAC (p<0.001). CONCLUSIONS: This preoperative score is useful in detecting patients who might have UAC and a better selection for an alkalinizing therapy can be performed. When facing a patient with a suspected UAC, the Score can be easily applied with simple data from CT scans and clinical records. A score of 3-4 is a powerful predictor of UAC and adds to clinical decision-making for alkalizing therapy, as other items for this purpose are lacking. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e954-e955 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mario Basulto-Martínez More articles by this author Silvia Proietti More articles by this author Maria Pia Pavia More articles by this author Luis Rico More articles by this author Yuyi Yeow More articles by this author Juan Pablo Flores-Tapia More articles by this author Antonio Esqueda-Mendoza More articles by this author Franco Gaboardi More articles by this author Guido Giusti More articles by this author Expand All Advertisement Loading ...