High-risk Stone Research Articles

The Yield of Genetic Testing in Management of Nephrolithiasis

ObjectiveTo describe the yield and indications for performing genetic testing in patients with nephrolithiasis. Genetic testing for nephrolithiasis is becoming more accessible and rapid due to technologic advances. This study aimed to determine the diagnostic yield of genetic testing in a cohort of high-risk stone formers and to identify 24-hour urine characteristics to prompt genetic screening. Materials and MethodsWe retrospectively identified patients who underwent genetic testing for nephrolithiasis from 2020-22 at a single institution using a custom PerkinElmer™ genomics panel for nephrolithiasis. We compared characteristics of patients with and without genetic abnormalities. We used receiver operator characteristic (ROC) analysis to identify candidate thresholds for genetic testing. ResultsFourteen of 36 patients (39%) who underwent genetic testing had identifiable mutations. Five patients (14%) had known pathogenic mutations, including genes for primary hyperoxaluria (PH2 and PH3), cystinuria, and enamel renal syndrome. The remaining mutations were variants of uncertain significance. Of the 14 patients with identified mutations, only 6 had concordant 24-hour urine abnormalities, including 3/5 with known pathogenic mutations. In patients with urine oxalate ≥40mg/day, 3/29 (10.3%) had PH2 or PH3. ROC analysis showed that an oxalate threshold of ≥80mg/day may have promising screening characteristics. ConclusionsGenetic testing for nephrolithiasis remains controversial due to unknown yield and the time and energy required to discuss results with patients. This preliminary report describes the yield and identifies clinical factors and a potential cut-off that may assist clinicians in deciding when genetic profiling should be pursued.

CASE SERIES AND REVIEW ON THE MANAGEMENT OF BLADDER CALCULI CAUSED BY IUD MIGRATION

Objective: Comparing two cases of the management of bladder calculi caused by Intra Uterine Device (IUD) migration with other similar cases worldwide. Case(s) Presentation: A forty-eight-year-old woman diagnosed by Abdominal Non-contrast Computed Tomography (NCCT), already done IUD extraction through the bladder approach also hysteroscopy to evaluate the position from the womb side, and continued with the stone removal by vesicolithotripsy. The second case revealed a bladder stone with IUD tail presence based on Kidney Ureter Bladder (KUB), performed vesicolithotomy, and IUD was found attached to the stone. Both patients’ conditions improved after surgeries. IUD migration into the bladder causes perforation, stone formation, and Urinary Tract Infection (UTI). NCCT, KUB, and Ultrasonography can be used as imaging modalities for initial screening when IUD migration is suspected. Discussion: The managements consist of open cystolithotomy, transurethral grasping forceps, or minimally invasive laparoscopy. Open and laparoscopic surgery should be considered for the IUD removal with partial penetration due to vesicouterine fistula and high-risk stone removal, especially for the large stone with IUD embedded inside. Conclusion: Minimally invasive methods are efficient, safe, and frequently preferred for the bladder stone caused by IUD migration. Keywords: Bladder stone, IUD, migration.

Impact of annual TB screening on stone quarry workers in high-incidence Portuguese municipalities.

<sec id="st1"><title>SETTING</title>The Portuguese municipalities of Penafiel and Marco de Canaveses are high TB incidence areas, where stone quarry workers represent a vulnerable population.</sec><sec id="st2"><title>OBJECTIVE</title>To assess the annual rate of TB infection (ARI) in stone quarry workers and to compare it with the TB notification rate in the general community.</sec><sec id="st3"><title>DESIGN</title>An annual TB infection screening strategy using interferon-gamma release assay (IGRA) was implemented in 2018 for workers from high-risk stone quarries. A prospective cohort was enrolled and workers screened in periods of 2 years were included. IGRA-positive workers were referred for preventive treatment. ARI was calculated as the proportion of workers with IGRA conversion.</sec><sec id="st4"><title>RESULTS</title>Of the 232 IGRA-negative workers in 2018, 20 tested positive in 2019 (8.6% ARI). Of 171 IGRA-negative workers in 2019, eight tested positive in 2021 (4.7% in 2 years). Two of the 150 IGRA-negative workers in 2021 tested positive in 2022 (1.3% ARI). ARI decreased by 84.9% between 2019 and 2022. In the two municipalities, the TB notification rate declined 23.9% between 2018 and 2021.</sec><sec id="st5"><title>CONCLUSION</title>A more pronounced reduction in ARI was observed among stone quarry workers regularly screened for TB infection compared to the notification rate among the general population in high-incidence municipalities. A screening strategy for high-risk populations, together with enforced community measures, could foster risk reduction in the community.</sec>.

The impact of kidney stone disease on quality of life in high-risk stone formers.

To assess the impact of kidney stone disease (KSD) and its treatment on the health-related quality of life (HRQOL) of high-risk stone formers with hyperparathyroidism, renal tubular acidosis, malabsorptive disease, and medullary sponge kidney. The Wisconsin Stone Quality of Life questionnaire was used to evaluate HRQOL in 3301 patients with a history of KSD from 16 institutions in North America between 2014 and 2020. Baseline characteristics and medical history were collected from patients, while active KSD was confirmed through radiological imaging. The high-risk group was compared to the remaining patients (control group) using the Wilcoxon rank-sum test. Of 1499 patients with active KSD included in the study, the high-risk group included 120 patients. The high-risk group had significantly lower HRQOL scores compared to the control group (P < 0.01). In the multivariable analyses, medullary sponge kidney disease and renal tubular acidosis were independent predictors of poorer HRQOL, while alkali therapy was an independent predictor of better HRQOL (all P < 0.01). Among patients with active KSD, high-risk stone formers had impaired HRQOL with medullary sponge kidney disease and renal tubular acidosis being independent predictors of poorer HRQOL. Clinicians should seek to identify these patients earlier as they would benefit from prompt treatment and prevention.

876 Are Patients Presenting Acutely with Renal Tract Calculi Routinely Given Dietary Advice?

Abstract Aim The risk of formation of renal calculi can be reduced by making changes to diet and fluid intake. NICE recommend that dietary advice is given to all patients presenting with renal tract calculi either at presentation or prior to discharge. The purpose of this study was to assess patients’ current knowledge and whether provision of the BAUS leaflet can improve this. Method At a district general hospital, patients who have had acute presentations with ureteric calculi who are conservatively managed are followed up in telephone ‘hot clinic’. Over a 3-month period, prior to clinic attendance, patients were invited to complete a questionnaire. Inclusion criteria: adults with an isolated presentation who are not high-risk stone formers. Results Of the 59 patients who attended seven clinics, 44 completed the questionnaire (70% male, mean age 46 (22, 83)). Only 10 (23%) of the patients recalled being given dietary advice at initial presentation, two of whom were given written advice. Thirty patients were aware that diet can impact on stone formation, however only 13 (30%) and 21 (48%) were aware that dietary protein and salt respectively can impact on stone formation. Knowledge of recommended fluid intake was good, with 31 (70%) correctly identifying 2-3 litres as adequate and only 2 (5%) stating that &amp;lt;1 litre is adequate. Conclusions With the exception of fluid intake, patient knowledge of dietary advice for stone formers is poor, due to lack of education provided at initial presentation. Educative measures and signposting to BAUS-approved resources may reduce risk of future stone formation.

Editorial Commentary.

No AccessUrology PracticeHealth Policy1 Mar 2023Editorial CommentaryThis article comments on the following:Potential for Urolithiasis-related Research Using the Novel Medicare-Litholink Database Julio G. Davalos Julio G. DavalosJulio G. Davalos * E-mail Address: [email protected] Chesapeake Urology Associates, Glen Burnie, Maryland More articles by this author View All Author Informationhttps://doi.org/10.1097/UPJ.0000000000000378.02AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "Editorial Commentary." Urology Practice, 10(2), p. 153 Reference 1. . Prevalence of 24-hour urine collection in high risk stone formers. J Urol. 2014; 191(2):376-380. Link, Google Scholar © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsRelated articlesUrology Practice25 Jan 2023Potential for Urolithiasis-related Research Using the Novel Medicare-Litholink Database Volume 10Issue 2March 2023Page: 153-153 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Julio G. Davalos Chesapeake Urology Associates, Glen Burnie, Maryland * E-mail Address: [email protected] More articles by this author Expand All Advertisement PDF downloadLoading ...

Metabolic evaluation of high-risk stone formers: a retrospective study

BackgroundThe purpose of this study was to assess the metabolic abnormalities in high-risk stone formers.MethodsThis was a retrospective observational study done at Tribhuvan University Teaching Hospital, Nepal, over 1-year period. High-risk stone formers were identified and were evaluated with serum chemistries and 24-h urinary chemical evaluation. Stone analysis was also included whenever available. Common metabolic abnormalities and stone analysis results were reported and compared with different studies. Continuous variables were expressed as mean ± SD. Categorical variables were expressed as percentage and proportions.ResultsDuring 1 year of period, sixty-five patients had undergone extensive metabolic evaluation, but complete data were available for only forty-six patients. Of the total patients (n = 46), 63% were male (n = 29) and rest (36.9%) were female. Mean age of patients was 34.4 ± 15.1 years. Common reasons for metabolic evaluation were multiple stones (40%), bilateral stones (27%), recurrent stones (17%) and others (16%). Most common stone type was mixed stone with predominant composition being calcium oxalate mono- and dihydrate (62.9%). Twenty-four-hour urinary metabolic evaluation showed hyperoxaluria (32.6%) as most common abnormalities followed by hypocitraturia (21.7%) and hypocalciuria (21.7%).ConclusionHyperoxaluria and hypocitraturia are common metabolic abnormalities in our patients. These findings help in counselling dietary measures to patients.

Metabolic evaluation of first-time uncomplicated renal stone formers: A prospective study.

Nephrolithiasis is a global health problem. The recurrence rate after the first stone clearance is approximately 50% at 5 years. Metabolic abnormalities are an important factor responsible for stone recurrence. Our prevalidated study aimed to evaluate metabolic abnormalities associated with first-time uncomplicated renal stone formers (FTURSF). In this prospective, exploratory, time-bound, descriptive study, 30 first-time renal stone formers were evaluated for metabolic abnormalities. High-risk stone formers were excluded from the study. Data were collected in a predefined proforma, transferred to an Excel sheet, and analyzed using the Statistical Package for Social Sciences 20 and Epi Info 7. Fisher exact test, Mann-Whitney U test, paired t test, and Pearson correlation coefficient were used for statistical analyses. The mean age of the participants was 35.57 ± 11.07 years, with a male-to-female ratio of 1.72. The most common abnormality was a 24-hour urine volume of <2.5 L in 73.33% of the participants. One or more metabolic abnormalities were detected in 76.67% of the participants. Other common metabolic abnormalities detected were hypocitraturia (60%), hypercalciuria (16.67%), hyperoxaluria (13.33%), and hyperuricosuria (3.33%). Parathyroid adenoma was detected in one participant (3.33%). Our study documented significant metabolic abnormalities in FTURSF. Therefore, a simplified metabolic evaluation protocol should be adopted while evaluating FTURSF. Detection of an underlying metabolic abnormality would enable the early institution of preventive measures to reduce stone recurrence and related complications.

Current Trends in Metabolic Evaluation of Patients with Urinary Tract Lithiasis

Abstract Urolithiasis is one of the most frequent disorders of the urinary tract with a high prevalence among the general population. The etiology is multifactorial and is related primarily with, race, age, gender, occupation, hygienic-dietetic issues, lifestyle factors, geographic and climatic aspects, hereditariness, and metabolic changes. Therefore, for prevention of the disease, the metabolic causes responsible for stone formation should be addressed before and particularly after treatment. Key point for the metabolic evaluation is to perform stone analysis and to classify patients into low- and high-risk group. In low-risk patients, basic metabolic evaluation is proposed comprising basic urine and blood tests. Spot urinalysis should include red cells, white blood cells, nitrite, urine pH, urine microscopy, and culture if indicated. Basic blood testing includes blood cell count, creatinine, uric acid, ionized calcium, sodium, potassium, and C-reactive protein if indicated. In high-risk stone formers, apart from the basic workup, analysis of two 24-h urine samples should be examined for evaluation of the total urine volume as well as the concentration of creatinine, calcium, phosphate, oxalate, urea nitrogen, uric acid, citrate, magnesium, sodium, and if indicated of cystine. Further examination should be based on the composition of stone. The follow-up of stone formers is still matter of debate, but most experts agree that the follow-up should be individualized according to stones composition, the underlying metabolic cause, and the treatment that has been offered.

Prophylaxis of Recurrent Stone Disease in Outpatient Clinics in Germany: A Quality-of-Care Concern

Introduction: The aim of the study was to survey current practices for preventing recurrent stone disease in an outpatient clinic setting in Germany. Methods: Two invitations to complete an anonymous REDCap® survey were emailed to members of the occupational union of German urologists who work as outpatient urologists (“Berufsverband Deutscher Urologen e.V.”). The survey included questions on diagnostic modalities and counselling to prevent stone disease. Results: A total of 130 outpatient urologists completed the survey. 84.6% of urologists give general advice to first-time stone formers. Recommendations comprise increased fluid uptake in 100%, two-thirds advice on calcium and oxalate intake, and one-third on salt and protein intake. 64.6% perform a metabolic evaluation for high-risk stone formers. However, patients with risk factors other than repeat stone disease are often overlooked. Urologists agreed that a lack of time (73.1%) and reimbursement (64.6%), as well as insufficient patient compliance (60.8%), pose significant challenges. The majority of urologists agreed that training is required. Conclusion: General recommendations for stone formers are usually provided, but nutritional advice tends to be incomplete. Our results raise quality-of-care concerns: Metabolic evaluation of stone formers at high risk of recurrence is uncommon. Structural changes are required due to time constraints, and poor remuneration must be addressed to improve patient care.

Comparative assessment of multiple‐tract vs single‐tract percutaneous nephrolithotomy

To investigate the efficacy and safety of multi-tract percutaneous nephrolithotomy (PNL) against the benchmark of the single-tract approach. A retrospective analysis of 391 consecutive PNL procedures was conducted in our tertiary referral center between April 2016 and March 2020. Clinical outcome parameters such as stone-free rate, operation time, postoperative complications according to Clavien-Dindo, length of hospital stay and time to ipsilateral recurrence resulting in active treatment were assessed. Multi-tract PNL and single-tract PNL were performed in 37 (9%) and 354 (91%) cases respectively. At baseline, compared to single-tract PNL, multi-tract PNL cases were characterized by significantly larger stone burden (2.62 vs 0.97 cm3 , P < .00), lower Hounsfield units (HU) (751 vs 1017 HU, P < .01), a more complex S.T.O.N.E. (size, tract length, obstruction, number of calyces, essence) score (P < .00) and a higher rate of high-risk stone formers (59 vs 19%, P < .00). Analysis of outcome revealed shorter operation time and length of hospital stay for single-tract PNL compared to multi-tract PNL (P < .01). However, the difference in terms of stone-free rates (92% vs 88%), complication rates (43% vs 28%) and time to active retreatment due to ipsilateral recurrence was not statistically significant (P > .05). In this retrospective single-center analysis, a multi-tract PNL has been proved to be an efficient and safe expansion of single-tract PNL for large stone burden and complex kidney stone disease. Future prospective research should focus on the procedure's potential effectiveness in reducing the number of interventions until stone-free status in patients with massive stone disease.

An empirical study on hospital-based prevention of recurrent urinary stone disease in Germany

PurposeUrinary stone disease is a common disease with a prevalence of 4.7% in Germany. The incidence increased over the last decades, and recurrence rates are up to 50% in the first 5 years after diagnosis. Adequate preventive measures can avoid up to 46% of stone recurrences. These numbers outline the importance of prevention. Especially among high-risk stone formers, specific diagnostics and measures are required. Published data indicate the divergence between the importance of prevention and its implementation in everyday clinical practice. This is the first survey among German urological departments highlighting medical care concerning the prevention of recurrent urinary stone disease, identifying challenges and providing recommendations for improvements.MethodsTwo hundred and seventy urological hospital departments in Germany were anonymously surveyed about measurements to prevent recurrent stone disease. The questionnaire comprised 23 items dealing with diagnostics, counselling, knowledge among doctors concerning preventive measures and difficulties in preventing recurrent urinary stone disease.ResultsSixty-three urological departments (23.8%) answered the survey. The majority perform stone analysis at first and repeat events. Most patients with urinary stone disease receive general advice on preventive measures during their hospitalization. General recommendations focus on fluid intake and lifestyle changes. However, specific diets are infrequently recommended by inpatient urologists. Diagnostics to identify high-risk stone formers are mostly insufficient, and guideline-compliant urine tests are uncommon.ConclusionThe quality of secondary prevention needs to improve considerably. The focus should be put on identifying high-risk stone formers and offering those patients specific counselling. Furthermore, general advice on dietary recommendations should be extended.

Endoscopic Papillary Abnormalities and Stone Recognition (EPSR) during Flexible Ureteroscopy: A Comprehensive Review.

Introduction: The increasing efficiency of the different lasers and the improved performance of endoscopic devices have led to smaller stone fragments that impact the accuracy of microscopic evaluation (morphological and infrared). Before the stone destruction, the urologist has the opportunity to analyze the stone and the papillary abnormalities endoscopically (endoscopic papillary recognition (EPR) and endoscopic stone recognition (ESR)). Our objective was to evaluate the value for those endoscopic descriptions. Methods: The MEDLINE and EMBASE databases were searched in February 2021 for studies on endoscopic papillary recognition and endoscopic stone recognition. Results: If the ESR provided information concerning the main crystallization process, EPR provided information concerning the origin of the lithogenesis and its severity. Despite many actual limitations, those complementary descriptions could support the preventive care of the stone formers in improving the diagnosis of the lithogenesis mechanism and in identifying high-risk stone formers. Conclusion: Until the development of an Artificial Intelligence recognition, the endourologist has to learn EPSR to minimize the distortion effect of the new lasers on the stone analysis and to improve care efficiency of the stone formers patients.

Reply by Authors.

You have accessJournal of UrologyReview Article1 Sep 2021Reply by Authorsis a reply to letterEditorial CommentEditorial Comment Eleanor Brain, Robert M. Geraghty, Catherine E. Lovegrove, Bingyuan Yang, and Bhaskar K. Somani Eleanor BrainEleanor Brain Newcastle Medical School, Newcastle-upon-Tyne, England More articles by this author , Robert M. GeraghtyRobert M. Geraghty *Correspondence: Department of Urology, Freeman Hospital, Freeman Road, Newcastle-upon-Tyne, UK telephone: 01913743848; E-mail Address: [email protected] http://orcid.org/0000-0002-9128-5173 Department of Urology, Freeman Hospital, Newcastle-upon-Tyne, England Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Newcastle upon Tyne, England More articles by this author , Catherine E. LovegroveCatherine E. Lovegrove Department of Urology, Churchill Hospital, Oxford, England Nuffield Department of Surgery, Oxford University, Oxford, England More articles by this author , Bingyuan YangBingyuan Yang Department of Urology, Churchill Hospital, Oxford, England Financial and/or other relationship with Boston Scientific Corp. More articles by this author , and Bhaskar K. SomaniBhaskar K. Somani http://orcid.org/0000-0002-6248-6478 Department of Urology, University Hospital Southampton, Southampton, England More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001836.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail We thank Drs. Sur, Emmott and Chew for their considered editorials. We agree wholeheartedly that the term “clinically insignificant fragments” should be made defunct. As pointed out there was significant heterogeneity in followup imaging, definition of disease progression and definition of stone-free status. We recommend these be standardized for future studies so they may be directly comparable in future. This will aid patient counseling and informed consent. We can recommend, following the results of this study that: for imaging, postoperative computerized tomography should become the gold standard, disease progression should be defined as symptomatology or stone growth and that “stone-free” be defined as truly stone-free (ie no residual fragments). This study implies that not only will patient quality of life suffer if we accept “clinically insignificant fragments” as a treatment end-point, but also the costs associated with their disease if repeated interventions or time off work are needed (reference 4 in article). This is especially true of shock wave lithotripsy; given the high number of fragments generated, inevitably some will remain that will cause issues in the future, especially in those with chronic kidney disease.1 Further study needs to be made on how to differentiate patients into those to discharge, those to surveil or those to intervene. This is perhaps an area for implementation of a stone screen to identify high risk stone formers utilizing artificial intelligence and including patient and stone demographics, traditional risk factors, monogenic screen, polygenic risk score and 24-hour urinary biochemistry (reference 31 in article). Reference 1. : Role of endourological procedures (PCNL and URS) on renal function: a systematic review. Curr Urol Rep 2020; 21: 21. Google Scholar © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsRelated articlesJournal of UrologyJun 16, 2021, 12:00:00 AMEditorial CommentJournal of UrologyJun 16, 2021, 12:00:00 AMEditorial Comment Volume 206Issue 3September 2021Page: 537-538 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Eleanor Brain Newcastle Medical School, Newcastle-upon-Tyne, England More articles by this author Robert M. Geraghty Department of Urology, Freeman Hospital, Newcastle-upon-Tyne, England Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Newcastle upon Tyne, England *Correspondence: Department of Urology, Freeman Hospital, Freeman Road, Newcastle-upon-Tyne, UK telephone: 01913743848; E-mail Address: [email protected] More articles by this author Catherine E. Lovegrove Department of Urology, Churchill Hospital, Oxford, England Nuffield Department of Surgery, Oxford University, Oxford, England More articles by this author Bingyuan Yang Department of Urology, Churchill Hospital, Oxford, England Financial and/or other relationship with Boston Scientific Corp. More articles by this author Bhaskar K. Somani Department of Urology, University Hospital Southampton, Southampton, England More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

Improving Compliance with 24-H Urine Collections: Understanding Inadequacies in the Collection Process and Risk Factors for Poor Compliance.

The purpose of this review paper is to describe the 24-h urine collection in terms of its utility, collection process, and common problems with its acquisition. Although 24-h urine collections are standard of care for high-risk stone formers, several nuances in test acquisition including inaccurate urine collections 50% of the time and poor patient compliance limit its potential utility. Compliance in obtaining 24-h urine collections has been shown to be improved in patients who have not undergone surgical treatment of urinary calculi, patients with metabolic stone disease or family history of stone disease, Caucasian ethnicity, and in those with more sedentary occupations. Studies show conflicting data of compliance regarding patient age and gender. Physicians must understand the difficulties regarding 24-h urine collections including patient compliance, variability between collections, and complexities with interpretation to best utilize this tool in guiding clinical management for the treatment of nephrolithiasis.

The Association Between 24-Hour Urine and Stone Recurrence Among High Risk Kidney Stone Formers: A Population Level Assessment

OBJECTIVETo determine if obtaining a 24-hour urine collection (24HU) in stone formers is associated with decreased recurrent stone episodes. METHODSUsing the MarketScan database, adults 17-62 years old with nephrolithiasis were identified between 2007 and 2017 with a minimum of 3-year follow up. High-risk stone formers, those undergoing stone surgery, and those with history of recurrent stones were identified. The exposure was a 24HU within 6 months of primary diagnosis. The outcome was recurrent stone episodes—defined by stone-related emergency room visits, hospitalizations, or stone surgery 90 days to 3 years after diagnosis. Logistic regression was used to estimate recurrence risk by 24HU exposure for the overall cohort and sub-cohorts limited to known recurrent stone formers, high-risk subjects, and those having stone surgery. RESULTSOf 434,055 subjects analyzed, 30,153 (6.9%) had a 24HU. An annual decline in 24HU utilization was seen (7.5%-5.8%). Regional variation in usage rate was also observed. On multivariate analysis, completing a 24HU was not associated with risk of recurrence in any of the following cohorts: recurrent stone formers (OR 0.98, 95% CI 0.9-1.07), both high risk and recurrent stone formers (OR 0.95 [0.8-1.13]), those undergoing surgery (OR 1.02 [0.97-1.07]); a positive association with 24HU and recurrence was seen in those labeled high-risk (OR 1.08 [1.01-1.16]) and in all-comers (OR 1.15 [1.12-1.19]). CONCLUSIONThe 24HU was not associated with decreased recurrence rates in the overall population nor in higher risk sub-cohorts.

Validity of STONE Score in Clinical Prediction of Ureteral Stone Disease.

Objective:To determine the external validity of STONE score for predicting the probability of ureteral stone in patients presenting in emergency department with suspicion of ureteral stones.Methods:In this prospective validation study, a total of 134 patients aged above 18 years, and first time arrived in the emergency unit for treatment of flank pain and then referred for the CT scan for suspected ureteral stone in Sandeman Provincial Hospital, Quetta, from 10-June-2018 to 15-Oct-2019 were included. STONE score calculation was done before sending the patient to the CT scan, using the same protocol as defined by Moore et al. Based on STONE score patients classified into the low-risk group (0 to 5), moderate-risk group (5 to 9) and the high-risk group (10 to13). The AUC, sensitivity, specificity and test characteristics were calculated for STONE score.Results:The mean age was 39.2± 11.2 years, there were 86 (64.17%) men and 48 (35.83%) women. there were 26.8% patients having low-risk score, 52.23% moderate-risk and 21.97% high-risk score. On receiver operating curve (ROC) the area under curve (AUC) of the stone score was 0.75 (95% CI, 0.67 to 0.83), the lower band of AUC 0.67 and upper band 0.83. In high risk STONE score the sensitivity of STONE score was 66.7% and specificity was 75.0%.Conclusion:Based on our study results, CT scan and ultrasonography are standard diagnostic tools for suspected ureterolithiasis but in emergency unit, use of STONE score to categorize the patient as low risk, moderate-risk and high-risk of ureteral stone can help the physician (clinician) to take decision either there is a need of further investigation or not.

MP08-06 THE ASSOCIATION BETWEEN 24-HOUR URINE COLLECTION USE AND STONE RECURRENCE AMONG HIGH RISK KIDNEY STONE FORMERS

INTRODUCTION AND OBJECTIVES:The American Urologic Association Guidelines recommends obtaining a 24-hour urine (24HU) in recurrent stone formers, patients high-risk for stone recurrence, and interested first-time stone formers. However, the advantage of selective therapy based on 24HU results over empiric treatment is unclear. We aimed to determine if obtaining a 24HU in high risk stone formers is associated with decreased recurrent stone episodes in a contemporary cohort exemplifying real-world clinical practice.METHODS:We used the MarketScan database to identify insured, employed subjects, 18 to 64 years old with a primary diagnosis of kidney and/or ureteral stones based on ICD-9 and ICD-10 diagnosis codes from 2008 to 2014. Subjects at high risk for infectious stones or with cystinuria were excluded. High risk stone formers (based on AUA guidelines), those undergoing stone surgery, and those with previous stone diagnoses one year prior to the date of inclusion were characterized with CPT and ICD codes, ...

Congenital and acquired diseases related to stone formation.

To summarize the latest findings of congenital and acquired diseases related to stone formation and help understanding the multitude of cofactors related to urolithiasis. Urolithiasis is related to a broad spectrum of congenital and acquired diseases and its management varies according to the stone type, underlying disease or recurrence rate, but it also changes according to recent findings and developments. As prevalence of urolithiasis is constantly increasing, identification of high-risk stone formers and early treatment is essential. Therefore, genetic evaluation like whole exome sequencing becomes a pertinent part of further diagnostics. Stone formation is a very heterogeneous pathomechanism. This prompt us to look at every patient individually particularly in high-risk patients, including stone and 24-h-urine analysis and additional diagnostic work-up based on stone type or underlying disease.

Metabolic evaluation guidelines in patients with nephrolithiasis: Are they being followed? Results of a national, multi-institutional, quality-assessment study.

The significant cost burden of kidney stones underscores the importance of best clinical practice in kidney stone management. We evaluated adherence to kidney stone metabolic evaluation guidelines in a Canadian population and the interest of patients with regard to prevention. A questionnaire based on Canadian Urological Association (CUA) best practice guidelines was designed. Patients presenting for extracorporeal shockwave lithotripsy treatment (ESWL) were administered this questionnaire to evaluate risk factors of stone disease and assess the use of metabolic evaluations. Patients were asked if they received explanations about their results and if they were interested in kidney stone prevention. We identified 530 patients at five academic institutions; 79.4% had at least one indication to receive a metabolic evaluation (high-risk stone formers), which increased to 96.6% if first-time stone formers whom reported an interest in metabolic evaluation were included. However, only 41.1 % of these patients had a metabolic evaluation. Endourologists ordered metabolic evaluation more often than other referring urologists (63.6% vs. 36.5%; p<0.001). Furthermore, urologists ordered metabolic evaluations more often than other prescribing physicians (68.9% vs. 31.1%; p<0.001). Sixty-two percent of patients received explanations about their metabolic evaluation results and 77.5% understood them. Regarding prevention, 84.1% and 83.8% were interested in more explanations and in following a diet or taking a medication, respectively. Adherence to CUA metabolic evaluation guidelines is suboptimal and could be improved by urologists referring patients for ESWL. Communication between physician and patient may not be adequate. The majority of stone formers are interested in kidney stone prevention.