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IntroductionKidney stone prevalence estimates vary depending on sampling methodology. We compared rates of patient-reported kidney stone disease to Electronic Health Records (EHR) kidney stone diagnosis using a common dataset to evaluate for socio-demographic differences in these populations, including between those with and without active care for kidney stones.MethodsFrom the All of Us research database, we identified 21,687 adult participants with both patient-reported medical history and EHR data. We extracted patient-reported kidney stone history and medical encounters for kidney stones from EHR. We compared differences in age, sex, race, education, employment status and healthcare access between patients with self-reported kidney stone history without EHR data to those with EHR-based diagnoses.ResultsIn this population, the self-reported prevalence of kidney stones was 8.6% overall (n=1877), including 4.6% (n=1004) who had self-reported diagnoses but no EHR data. Among those with self-reported kidney stone diagnoses only, the median age was 66, 43% were male, and 92% were Non-Hispanic Whites, compared 120,623 (53.9%) in the entire All of Us cohort. The EHR-based prevalence of kidney stones was 5.7% (n=1231), median age 67, of whom 45% were male and 92% were Non-Hispanic White. No differences were observed in age, sex, education, employment status, rural/urban status, or ability to afford healthcare between groups with EHR diagnosis or self-reported diagnosis only. Of patients who had a self-reported history of kidney stones, 24% reported actively seeing a provider for kidney stones.ConclusionsKidney stone prevalence by self-report is higher than EHR-based prevalence in this national dataset. Using either method alone to estimate kidney stone prevalence may exclude some patients with the condition, although the demographic profile of both groups is similar. Approximately one in four patients report actively seeing a provider for stone disease.

PURPOSE: Recent observational studies reporting a lack of benefit from 24-hour urine testing for urinary stone disease (USD) prevention assumed testing included all components recommended from clinical guidelines. We sought to assess the completeness of 24-hour urine testing in the VA population. MATERIALS AND METHODS: From the VHA Corporate Data Warehouse (2012–2019), we identified patients with USD (n=198,621) and determined those who saw a urologist and/or nephrologist, and received 24-hour urine testing within 12 months of their index USD encounter. Through Logical Observation Identifiers Names and Codes, we evaluated each collection’s completeness, defined as including all of urine volume, calcium, oxalate, citrate, uric acid, and creatinine. We then fit a multilevel logistic regression model with random effects for VHA facility to evaluate factors associated with specialist follow-up, testing, and testing completeness. RESULTS: Specialist follow-up occurred in 54.3% and was stable over time. Testing occurred in 8.4%, declining from 9.3% in 2012 to 7.2% in 2019. Of tests performed, 54.6% were complete (43.7% increasing to 62.7% from 2012–2019). In adjusted analysis, there was high between-facility variation in specialist follow-up (median OR 2.0; 95% CI 1.7–2.0), testing (median OR 2.2, 95% CI 1.9–2.4), and testing completeness (median OR, 6.0, 95% CI 4.5–7.3). Individual facilities contributed 52% (intraclass correlation coefficient, 0.52; 95% CI, 0.44–0.57) towards the observed variation in testing completeness. CONCLUSIONS: Approximately 1 in 12 U.S. Veterans with USD receive metabolic testing and half of these tests are complete. Addressing facility level variation in testing completeness may improve USD care.

Objective: To assess the effect of 2 over-the-counter alkalizing agents on 24 hour urinary parameters. Materials and Methods: Ten healthy volunteers without a history of kidney stones were recruited to complete a baseline 24 hour urinalysis with a 4 day diet inventory. Participants then maintained the same diet on either LithoLyte (20 mEq 2 times per day) or KSPtabs (1 tablet 2 times per day) and submitted another 24 hour urinalysis. The process was repeated with the other supplement. Urinary alkali parameters were compared to baseline, and side effects were elicited with a questionnaire. Results: LithoLyte intake resulted in a non-significant increase in citrate (597-758 mg/day, P =.058, an increase in urine pH (6.46-6.66, P =.028), and a decrease in urine ammonium (41-36 mmol/day, P =.005) compared to baseline. KSPtabs resulted in an increase in citrate (597-797 mg/day, P =.037) and urine pH (6.46-6.86, P =.037), with a non-significant decrease in ammonium (41-34 mmol/day, P =.059). No significant differences were seen comparing urinary analytes between LithoLyte and KSPtabs. With Litholyte, no side effects, mild, moderate, and severe side effects were seen in 50%, 40%, 10%, and 0%, respectively. With KSPtabs, rates were 60%, 20%, 10%, and 10%, respectively. Conclusion: In healthy participants without a history of kidney stones, LithoLyte and KSPtabs are effective over-the-counter alkali supplements, with a similar side effect profile to prescription potassium citrate.

Treatment of struvite kidney stones requires complete surgical stone removal combined with antibiotic therapy to eliminate urinary tract infections and preventive measures to reduce stone recurrence. The optimal duration of antibiotic therapy is unknown. We sought to determine if 2- or 12-weeks of antibiotics post percutaneous nephrolithotomy (PNL) for infection stones resulted in better outcomes for stone recurrence and positive urine cultures.This multi-center, prospective randomized trial evaluated patients with the clinical diagnosis of infection stones. Patients were randomized to 2- or 12-weeks of postoperative oral antibiotics (nitrofurantoin or culture-specific antibiotic) and included if residual fragments were ≤4 mm on computed tomography imaging after PNL. Imaging and urine analyses were performed at 3-, 6-, and 12-months post-procedure.Thirty-eight patients were enrolled and randomized to either 2-weeks (n = 20) or 12-weeks (n = 18) of antibiotic therapy post-PNL. Eleven patients were excluded due to residual fragments4 mm, and 3 patients were lost to follow-up. The primary outcome was the stone-free rate (SFR) at 6 months post-PNL. At 3-, 6-, and 12-months follow-up, SFRs were 72.7% versus 80.0%, 70.0% versus 57.1%, 80.0% versus 57.1% (p = ns), between 2- and 12-week-groups, respectively. At 3-, 6-, and 12-months follow-up, positive urine cultures were 50.0% versus 37.5%, 50.0% versus 83.3%, and 37.5% versus 100% between 2- and 12-week groups, respectively (p = ns).For patients with stone removal following PNL, neither 2-weeks nor 12-weeks of postoperative oral antibiotics is superior to prevent stones and recurrent positive urine cultures.

To compare the frequency of stone-related events among patients receiving thiazides, alkali citrate, and allopurinol without prior 24 h urine testing. It is unknown whether 1 preventative pharmacological therapy (PPT) medication class is more beneficial for reducing kidney stone recurrence when prescribed empirically.Using medical claims data from working-age adults with kidney stone disease diagnoses (2008-2018), we identified those prescribed thiazides, alkali citrate, or allopurinol. We excluded those who received 24 h urine testing prior to initiating PPT and those with less than 3 years of follow-up. We fit multivariable regression models to estimate the association between the occurrence of a stone-related event (emergency department visit, hospitalization, or surgery for stones) and PPT medication class.Our cohort consisted of 1834 (60%), 654 (21%), and 558 (18%) patients empirically prescribed thiazides, alkali citrate, or allopurinol, respectively. After controlling for patient factors including medication adherence and concomitant conditions that increase recurrence risk, the adjusted rate of any stone event was lowest for the thiazide group (14.8%) compared to alkali citrate (20.4%) or allopurinol (20.4%) (each P.001). Thiazides, compared to allopurinol, were associated with 32% lower odds of a subsequent stone event by 3 years (OR 0.68, 95% CI 0.53-0.88). No such association was observed when comparing alkali citrate to allopurinol (OR 1.00, 95% CI 0.75-1.34).Empiric PPT with thiazides is associated with significantly lower odds of subsequent stone-related events. When 24 h urine testing is unavailable, thiazides may be preferred over alkali citrate or allopurinol for empiric PPT.

Objectives: To assess the accuracy of machine learning models in predicting kidney stone composition using variables extracted from the electronic health record (EHR). Materials and Methods: We identified kidney stone patients (n = 1296) with both stone composition and 24-hour (24H) urine testing. We trained machine learning models (XGBoost [XG] and logistic regression [LR]) to predict stone composition using 24H urine data and EHR-derived demographic and comorbidity data. Models predicted either binary (calcium vs noncalcium stone) or multiclass (calcium oxalate, uric acid, hydroxyapatite, or other) stone types. We evaluated performance using area under the receiver operating curve (ROC-AUC) and accuracy and identified predictors for each task. Results: For discriminating binary stone composition, XG outperformed LR with higher accuracy (91% vs 71%) with ROC-AUC of 0.80 for both models. Top predictors used by these models were supersaturations of uric acid and calcium phosphate, and urinary ammonium. For multiclass classification, LR outperformed XG with higher accuracy (0.64 vs 0.56) and ROC-AUC (0.79 vs 0.59), and urine pH had the highest predictive utility. Overall, 24H urine analyte data contributed more to the models' predictions of stone composition than EHR-derived variables. Conclusion: Machine learning models can predict calcium stone composition. LR outperforms XG in multiclass stone classification. Demographic and comorbidity data are predictive of stone composition; however, including 24H urine data improves performance. Further optimization of performance could lead to earlier directed medical therapy for kidney stone patients.

Purpose: We sought to assess the performance of the Recurrence of Kidney Stones nomogram for risk stratification of recurrence in a retrospective study. Materials and Methods: We performed a case-control study of 200 patients (100 with and 100 without subsequent recurrence) who underwent kidney stone surgery between 2013-2015, with at least 5 years of follow-up. We analyzed the performance of the 2018 ROKS nomogram via area under the receiver operating curve (ROC-AUC) for predicting 2- and 5-year stone recurrence. We evaluated the nomogram’s ability to stratify patients based on low or high risk of recurrence at: a) an optimized cutoff threshold (i.e. optimized for both sensitivity and specificity), and b) a sensitive cutoff threshold (i.e. high sensitivity (0.80) and low specificity). Time-to-recurrence data were estimated using the Kaplan Meier method. Results: The ROKS nomogram demonstrated fair ability to predict recurrence at 2 and 5 years (ROC-AUC of 0.67 and 0.63, respectively). At the optimized cutoff threshold, recurrence rates for the low and high-risk groups were 20 % and 45% at two years, and 50% and 70% at five years, respectively. At the sensitive cutoff threshold, the corresponding recurrence rates for the low and high-risk groups was of 16% and 38% at two years, and 42% and 66% at five years, respectively. Kaplan-Meier analysis revealed a significant recurrence-free advantage between the groups for both cutoff thresholds (pConclusions: The ROKS nomogram could serve as a tool for recurrence risk stratification into lower and higher risk groups and facilitate adherence to risk-based follow-up protocols.

Kidney stone cultures can be beneficial in identifying bacteria not detected in urine, yet how stone cultures are performed among endourologists, under what conditions, and by what laboratory methods remain largely unknown. Stone cultures are not addressed by current clinical guidelines. A comprehensive REDCap electronic survey sought responses from directed (n = 20) and listserv elicited (n = 108) endourologists specializing in kidney stone disease. Questions included which clinical scenarios prompt a stone culture order, how results influence post-operative antibiotics, and what microbiology lab protocols exist at each institution with respect to processing and resulting stone cultures. Logistic regression statistical analysis determined what factors were associated with performing stone cultures. Of 128 unique responses, 11% identified as female and the mean years of practicing was 16 (range 1-46). A specific 'stone culture' order was available to only 50% (64/128) of those surveyed, while 32% (41/128) reported culturing stone by placing a urine culture order. The duration of antibiotics given for a positive stone culture varied, with 4-7 days (46%) and 8-14 days (21%) the most reported. More years in practice was associated with fewer stone cultures ordered, while higher annual volume of percutaneous nephrolithotomy was associated with ordering more stone cultures (p 0.01). Endourologists have differing practice patterns with respect to ordering stone cultures and utilizing the results to guide post-operative antibiotics. With inconsistent microbiology lab stone culture protocols across multiple institutions, more uniform processing is needed for future studies to assess the clinical benefit of stone cultures and direct future guidelines.

Motivation Making sense of networked multivariate association patterns is vitally important to many areas of high-dimensional analysis. Unfortunately, as the data-space dimensions grow, the number of association pairs increases in O(n2); this means that traditional visualizations such as heatmaps quickly become too complicated to parse effectively. Results Here, we present associationSubgraphs: a new interactive visualization method to quickly and intuitively explore high-dimensional association datasets using network percolation and clustering. The goal is to provide an efficient investigation of association subgraphs, each containing a subset of variables with stronger and more frequent associations among themselves than the remaining variables outside the subset, by showing the entire clustering dynamics and providing subgraphs under all possible cutoff values at once. Particularly, we apply associationSubgraphs to a phenome-wide multimorbidity association matrix generated from an electronic health record and provide an online, interactive demonstration for exploring multimorbidity subgraphs. Availability and implementation An R package implementing both the algorithm and visualization components of associationSubgraphs is available at https://github.com/tbilab/associationsubgraphs. Online documentation is available at https://prod.tbilab.org/associationsubgraphs_info/. A demo using a multimorbidity association matrix is available at https://prod.tbilab.org/associationsubgraphs-example/.

Clinical guidelines disagree on whether the identification of abnormal urine chemistries should occur before starting diet and medication interventions to prevent the recurrence of kidney stone events. We describe the rationale and design of the Urinary supersaturation in a Randomized trial among Individuals with Nephrolithiasis comparing Empiric versus selective therapy (URINE) study, a randomized trial comparing two multi-component interventions to improve urinary supersaturation. Participants are randomized (1:1 ratio) to the empiric or selective arm. The target sample size is 56 participants. Adults ≥ 18 years of age with idiopathic calcium stone disease and two symptomatic stone events within the previous 5 years. Exclusion criteria include systemic conditions predisposing to kidney stones and pharmacologic treatment for stone prevention at baseline. Participants in the empiric arm receive standard diet therapy recommendations, thiazide, and potassium citrate. Participants in the selective arm receive tailored diet and nutrient recommendations and medications based on baseline and 1-month follow-up of 24-h urine testing results. The primary endpoints are urinary supersaturations of calcium oxalate and calcium phosphate at 2 months of follow-up. Secondary endpoints include side effects, diet and medication adherence, and changes in 24-h urine volume, calcium, oxalate, citrate, and pH. Short-term changes in urinary supersaturation may not reflect changes in future risk of stone events. The URINE study will provide foundational data to compare the effectiveness of two prevention strategies for kidney stone disease.

Purpose: Kidney stone recurrence rates vary between patients. A patient's risk informs the frequency and intensity of preventative interventions. Clinicians routinely use clinical experience to est...

To characterize stone-related financial toxicity among US adults with kidney stones through validated questionnaires for financial toxicity and disease-specific health-related quality of life.We performed a cross-sectional survey of adults with kidney stone disease from the general population ascertained through a national registry of volunteers (ResearchMatch). A computer-based survey queried stone event history and related costs for medical care, disease-specific quality of life (WISQOL), and an 11-item measure of stone-related financial toxicity (COST-11 score). Multivariable logistic regression was performed to evaluate predictors of financial toxicity, defined as having a COST-11 score ≤20.Of 942 responses, median COST-11 score was 29 (IQR 21-38), and 24.7% (N = 233) met criteria for disease-specific financial toxicity. Stone-formers with financial toxicity spent more out of pocket on stone-treatment in the previous year than patients with lower financial burden (P.001) and were more likely to defer or delay recommended treatment due to anticipated cost (27% vs 3%; P.001). Stone-specific financial toxicity was associated with poorer disease-specific health-related quality of life across all WISQOL domains (each P.001). Multivariable logistic regression showed that female gender (OR 1.81; 95% CI 1.24-2.67), Medicaid compared to private insurance (OR 3.91; 95% CI 2.34-6.94), and stone passage in the previous year (OR 2.00; 95% CI 1.41-2.86) were independently associated with financial toxicity.Approximately 1 in 4 individuals with kidney stone disease report disease-specific financial toxicity. These data suggest the financial burden of the condition may influence decision-making and associates with poorer disease-specific quality of life.

Objective To describe the associations between elevated urinary ammonium and clinical characteristics of kidney stone formers. A 24-hour urine test is recommended in high-risk patients to identify urinary abnormalities and select interventions to reduce the recurrence risk. While elevations in urine ammonium may be seen in acidosis, diarrhea, high protein diets or due to pathogenic bacteria, the clinical characteristics of these patients have not been previously described. Methods We retrospectively identified adult patients with kidney stone disease who completed a 24-hour urine at our institution between 2006 and 2017. Patients with elevated urinary ammonium were identified (n = 121) and matched 1:1 by age and sex to controls for an overall cohort of n = 242. Differences in medical and surgical history, 24-hour urine analytes and stone composition were compared. Results Among 3625 24-hour urine studies screened, 7.1% of patients showed high urinary ammonium. In our study cohort, patients with elevated urinary ammonium also showed higher urine volume, oxalate, calcium, uric acid, sodium, chloride, and sulfate. Clinically, these patients had higher body mass index, and more often had a history of recurrent urinary tract infections, diabetes, gout, bowel resection, and urinary reconstruction history. Struvite stones tended to be more common in the elevated ammonium group vs control (n = 7 vs 1, P = .07). Conclusion Elevated urinary ammonium among kidney stone patients is relatively uncommon. However, these patients have higher rates of comorbid metabolic conditions, urinary tract infections, and bowel surgery. This finding should prompt further review of the patient's history and may help direct prevention strategies.

OBJECTIVES To assess the change in rates of recurrence-free survival (RFS) and progression-free survival (PFS) based on the duration of survival without recurrence or progression among patients with intermediate-risk (IR) non-muscle-invasive bladder cancer (NMIBC), and to examine the predictive factors for recurrence at different time points by assessing conditional RFS and PFS. PARTICIPANTS AND METHODS A cohort of 602 patients treated with transurethral resection of bladder tumour and histopathologically diagnosed with IR NMIBC was included in this retrospective study. RESULTS The conditional RFS rate at 1, 2, 3, 4 and 5 years improved with increased duration of RFS; however, the conditional PFS rate did not improve over time. Multivariable analyses showed that recurrent tumour, multiple tumours, tumour size (>3 cm), immediate postoperative instillation of chemotherapy, and administration of BCG were independent predictive factors for recurrence at baseline. The predictive ability of these factors disappeared with increasing recurrence-free survivorship. Subclassification of these patients with IR NMIBC into three groups using clinicopathological factors (recurrent tumour, multiple tumours, tumour size) demonstrated that the high IR group (two factors) had significantly worse RFS than the intermediate (one factor, P < 0.001) and low IR groups (no factor, P = 0.005) at baseline. This subclassification stratified conditional risk of RFS also at 1, 3 and 5 years, which provides the basis for distinct surveillance protocols among patients with IR NMIBC. CONCLUSION Conditional survival analyses of patients with IR NMIBC demonstrate that RFS changes over time, while PFS does not change. These data support distinct surveillance protocols based on the subclassification of IR NMIBC.

In-flight medical events are rare but may cause significant distress as access to care is limited. There is a paucity of data on in-flight urological medical events. We describe urological in-flight medical emergencies and report clinical and flight outcomes.We reviewed all in-flight urological medical emergencies between 2015 and 2017 from MedAire®, a ground based medical support center that provides remote medical advisory services to approximately 35% of commercial airline passenger traffic worldwide. Our primary end point was the incidence rates of in-flight urological medical events. We also characterized the types of in-flight medical emergencies, in-flight management and their impact on flight status. Statistical analyses included Student's t-tests, chi-square analysis and analysis of variance.We identified 1,368 (1%) urological in-flight medical emergencies from a total of 138,612 in-flight medical emergencies, with an incidence of 0.5 per million passengers. The most common in-flight medical emergencies were lower urinary tract symptoms (35%), urinary retention (30%) and flank pain (21%). Among in-flight medical emergencies 883 (60%) resolved in flight, 273 (28%) required on-arrival medical evaluation and 21 (1.5%) resulted in flight diversions. Of the flight diversions the majority were due to urinary retention (12, 57%) and less commonly flank pain (6, 28%) and testicular/abdominal pain (3, 15%).The most common causes of urological in-flight medical emergencies are lower urinary tract symptoms, urinary retention and renal colic, the majority of which resolved in flight. These data are useful for informing flight personnel and emergency kit equipment needs to minimize the impact of these events when they occur.

We perform finite element modeling of pulse-echo ultrasound of a hard inclusion in a soft tissue to gain a better understanding of B-mode image brightness characteristics. We simulate a pressure wave emitted by an ultrasound transducer through the inclusion-tissue medium by prescribing suitable boundary conditions, and collect the scattered wave response to simulate the behavior of the transducer array used for pulse-echo ultrasound. We form B-mode images from simulated channel data using standard delay and sum beamforming. We establish the accuracy of the finite element model by comparing the point spread function with that obtained from Field II ultrasound simulation program. We also demonstrate qualitative validation by comparing the brightness characteristics of rough and smooth surfaced circular inclusions with experimental images of a cylindrical metal tool immersed in a water tank. We next conduct simulation studies to evaluate changes in B-mode image brightness intensity and contrast related to different constitutive properties, namely, compressibility of the inclusion, impedance contrast between the host and inclusion, and surface roughness of the inclusion. We find that the intensity observed behind a hard inclusion in the axial direction is strongly affected by the compressibility and roughness of the inclusion. Also, the perceived width of the stone based on the intensity is greater for rougher stones. Our study indicates that imaging of compressible inclusions may benefit from targeted B-mode image forming algorithms. Our modeling framework can potentially be useful in differentiating hard inclusions from surrounding parenchyma, and for classifying kidney stones or gallstones.

Purpose of review The 24-h urine test is recommended as part of the metabolic evaluation for patients with nephrolithiasis to guide preventive interventions. However, this test may be challenging to interpret and has limits in its predictive ability. In this review, we summarize and discuss the most recent research on the opportunities and challenges for utilizing urinary biomarkers for kidney stone prevention. Recent findings Contemporary studies utilizing the 24-h urine test have improved our understanding of how to better administer testing and interpret test results. Beyond the standard panel of 24-h urine parameters, recent applications of proteomics and metabolomics have identified protein and metabolic profiles of stone formers. These profiles can be assayed in future studies as potential biomarkers for risk stratification and prediction. Broad collaborative efforts to create large datasets and biobanks from kidney stone formers will be invaluable for kidney stone research. Summary Recent advances in our understanding of kidney stone risk have opened opportunities to improve metabolic testing for kidney stone formers. These strategies do not appear to be mutually exclusive of 24-h urine testing but instead complementary in their approach. Finally, large clinical datasets hold promise to be leveraged to identify new avenues for stone prevention.

Introduction: Kidney stones affect 1 in every 11 people in the United States each year. There is a significant high recurrence rate without a stone prevention protocol. Alkali citrate is beneficial in decreasing stone recurrence, but because of the cost and gastrointestinal side effects there is a low adherence rate. This study aims to serve as a review of some of the most commonly used alkalizing over-the-counter supplements that are advertised to prevent and treat kidney stones. Methods: Data were gathered by a comprehensive online literature search and company inquiries for kidney stone prevention supplements. An additional informal poll of the authors selected supplements that are most commonly taken by their patients. A total of eight supplements were evaluated for cost, alkali equivalent provided, dosing, and regulatory information. Results: Eight of the most commonly used supplements were reviewed with a focus on alkalizing agents. Information reviewed revealed dosing recommendations resulting in decreased citrate alkali equivalents per day compared with prescription-strength potassium citrate. Cost, peer-reviewed study results, and regulatory data were reviewed, tabulated, and analyzed. Cost per alkali equivalent was substantially decreased for each supplement compared with the prescribed drug. All supplements were found to be readily available online. Conclusion: Over-the-counter alkalizing agents are available to patients and may be an appropriate alternative to cost-prohibitive potassium citrate when treating urolithiasis patients. Additional testing will be necessary in the future to determine the efficacy of these supplements in the treatment and prevention of urinary stone disease.

Proton pump inhibitors (PPIs) are widely prescribed medications that have effects on both enteric and urinary solute handling with an unknown effect on risk of nephrolithiasis. Our objectives were to examine the association between PPI exposure and incident nephrolithiasis and to determine its effect on 24H urine chemistry. We performed a single-center retrospective study on patients diagnosed with gastroesophageal reflux disease (GERD) without a history of kidney stones. Exposure to PPIs was abstracted, and then subsequent kidney stone diagnoses were identified. Multivariable Cox models with time-varying covariates were used to estimate the hazard of PPI use on incident nephrolithiasis. We used multivariable linear regression to analyze a subset of patients who went through 24-h urine analysis. We identified n = 55,765 PPI-naïve GERD patients without prior kidney stone diagnoses of whom 40,866 (73.2%) were exposed to PPI over a median of 3 year follow up. On multivariable analysis, PPI use was associated with higher risk of incident kidney stone diagnoses (HR 1.19, 95% CI 1.06-1.34). Among 593 patients with GERD with 24-H urine data, the PPI-exposed group (n = 307) had significantly lower mean urinary citrate (mean 3.0 vs 3.4 mmol, p = 0.029) and urinary magnesium (mean 3.6 vs 4.3 mmol, p 0.001) on multivariable analyses. Exposure to PPIs is associated with an increased risk of kidney stones among patients with GERD. Hypomagnesemia and hypocitraturia associated with PPI exposure may contribute to kidney stone risk.

Patients with histological variants (HV) of bladder cancer have more advanced disease and poorer survival rates than those with pure urothelial carcinoma (UC). Moreover, lymphovascular invasion (LVI) is an important biomarker after RNU in systematic reviews and meta-analyses. Thus, here we investigated the clinical and prognostic impact of HV and LVI in patients with upper tract urothelial carcinoma (UTUC) treated with radical nephroureterectomy (RNU).Data from 223 UTUC patients treated with RNU without neoadjuvant chemotherapy were retrospectively evaluated. We analyzed differences in clinicopathological features and survival rates between patients with pure UC and those with HV. Conditional survival (CS) analysis was performed to obtain prognostic information over time.A total of 32 patients (14.3%) had HV, with the most common variant being squamous differentiation, followed by glandular differentiation. UTUC with HV was significantly associated with advanced pathological T stage (pT ≥ 3), higher tumor grade (G3), and LVI, compared to pure UC (all P0.01). Progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS), were all significantly worse in the HV group compared to the pure UC group (all, P0.001). In multivariable analysis, HV and LVI were independent predictors of CSS and OS. We classified the patients into three groups using these two predictors: low-risk (neither HV nor LVI), intermediate-risk (either HV or LVI), and high-risk (both HV and LVI). Significant differences in PFS, CSS, and OS rates were found among the 3 groups. In CS analysis, the conditional PFS, CSS, and OS rates at 1, 2, 3, 4, and 5 years improved with increased duration of event-free survival. CS analysis revealed that most progression events occurred within 2 years after RNU, and patients with risk factors had worse PFS at all time points.A risk model using HV and LVI can stratify PFS, CSS, and OS of patients treated with RNU. In addition, CS analysis revealed that HV and LVI were poor prognostic factors over time after RNU.

INTRODUCTION AND OBJECTIVE:Given recent studies that show similar recurrence outcomes among patients with urinary stone disease regardless of whether 24-hour urine testing is evaluated prior to ini...

INTRODUCTION AND OBJECTIVE:Kidney stone disease is a condition characterized by recurring stone events over time. Given the chronic nature of the condition and varying individual risk for recurrenc...

INTRODUCTION AND OBJECTIVE:The experience for patients who make a selection between observation or surgery for renal calculi has not been well established. We compared the experiences of patients w...

INTRODUCTION AND OBJECTIVE:To enable earlier preventative interventions or guide empiric therapy for kidney stone disease, our objective was to demonstrate feasibility of predicting 24-hour urine a...

INTRODUCTION AND OBJECTIVE:Recent studies show no benefit to a selective approach to preventive pharmacological therapy (PPT) for patients with urinary stone disease (i.e., obtaining 24-hour urine ...

INTRODUCTION AND OBJECTIVE:While surgical stone treatment falls under the domain of Urology, stone prevention is often the responsibility of nephrologists, endocrinologists, and primary care physic...

INTRODUCTION AND OBJECTIVE:Significant increases in kidney stone prevalence have been reported for Black and Hispanic individuals in the US, but the gender-specific contribution to this trend is un...

INTRODUCTION AND OBJECTIVE:Proton pump inhibitors (PPIs) are widely prescribed medications that have effects on both gastrointestinal and renal function with an unknown effect on risk of nephrolith...

INTRODUCTION AND OBJECTIVE:Urinary citrate is a potent inhibitor of kidney stones; hypocitraturia is a common abnormality in the recurrent stone former. The American Urological Association guidelin...