Long-term Urological Outcomes in Pelvic Genitourinary Rhabdomyosarcoma: A 48-Year Single-center Experience.

PURPOSE: Multimodal therapy has improved survival in genitourinary rhabdomyosarcoma, a rare pediatric cancer. However, little is reported regarding postoperative complications and long-term urinary and sexual function and quality of life. MATERIALS AND METHODS: We reviewed records from 1970-2018 to identify patients with genitourinary rhabdomyosarcoma of the bladder, prostate, pelvis, vagina, and uterus. We assessed modes of therapy, and if surgical, the type of resection, reconstruction, and reoperation. Primary outcomes included urinary continence, urinary tract infection occurrence, and stone formation. We also surveyed patients older than 18 years for urinary and sexual function. RESULTS: Fifty-one patients were identified for the post-treatment outcomes cohort. All received chemotherapy, 46 (90.2%) underwent surgery, and 34 (67%) received radiation. Twenty-nine patients (56.9%) received trimodal therapy, 17 (33.3%) received chemotherapy/surgery, and 5 (9.8%) received chemotherapy/radiation. Twenty-six had up-front radical surgery (with staged continence mechanism creation); these patients had higher rates of continence, similar rates of urinary tract infection, and higher rates of stone formation compared to those who were organ-spared. A third (4/12) of organ-spared patients underwent additional corrective surgery. Thirty patients with genitourinary rhabdomyosarcoma were surveyed and 14 responded to questionnaires. Overall, urinary complaints were mild, but both male and female respondents reported significant sexual dysfunction. CONCLUSIONS: Organ-sparing treatment was more likely to predispose patients to high rates of additional reconstructive surgery due to compromised urological function. In survey results, both men and women reported poor sexual function, but the majority of patients remained satisfied with their urinary function.

Hybrid Clinics: A New Model for Ambulatory Care to Reduce Infection Risk.

Objectives: To assess the viability of a hybrid clinic model combining in-person examination with video-based consultation to minimize viral transmission risk. Methods: Data were collected prospectively in a pediatric urology clinic for in-person visits from January to April 2018 ("classic") and hybrid visits from October to December 2020 of the COVID-19 pandemic ("hybrid"). Variables included provider, diagnosis, patient type, time of day, prior surgery, postoperative status, and decision-making for surgery. The primary outcome was "room time" or time in-person. The secondary outcome was "total time" or visit duration. Proportion of visits involving close contact (room time ≥15 min) was assessed. Univariate analyses were performed using the Wilcoxon rank-sum test and Fisher's exact test. Mixed models were fitted for visit approach and other covariates as fixed effects and provider as random effect. Results: Data were collected for 346 visits (256 classic, 90 hybrid). Hybrid visits were associated with less room time (median 3 min vs. 10 min, p < 0.001) but greater total time (median 13.5 min vs. 10 min, p = 0.001) as compared with classic visits. On multivariate analysis, hybrid visits were associated with 3 min less room time (95% confidence intervals [CIs]: -5.3 to -1.7, p < 0.001) but 3.8 min more total time (95% CI: 1.5-6.1, p = 0.001). Close contact occurred in 6.7% of hybrid visits, as compared with 34.8% of classic visits (p < 0.001). Conclusions: Hybrid clinic visits reduce room time as compared with classic visits. This approach overcomes the examination limitations of telemedicine while minimizing viral transmission, and represents a viable model for ambulatory care whenever close contact carries infection risk.

Dietary Risk Factors for Pediatric Kidney Stones: A Case-Control Study.

PURPOSE: Data are scarce regarding dietary risk factors for pediatric nephrolithiasis. Our objective was to perform a case-control study (nonmatched) of the association of dietary nutrients with pediatric urolithiasis. MATERIALS AND METHODS: We obtained dietary information from pediatric urolithiasis patients (from stone clinic in 2013-2016) and healthy controls (well-child visit at primary care in 2011-2012). Survey results were converted to standard nutrient intakes. Children younger than 5 years of age and those with extreme calorie intake values (<500 or >5,000 kcal/day) were excluded. The association of individual nutrients with urolithiasis was assessed by bivariate analysis results and machine-learning methods. A multivariable logistic regression model was fitted using urolithiasis as the outcome. RESULTS: We included 285 patients (57 stones/228 controls). Mean±SD age was 8.9±3.6 years (range 5-20). Of the patients 47% were male. After adjusting for age, sex, body mass index (obese/overweight/normal), calorie intake and oxalate, urolithiasis was associated with higher dietary sodium (OR=2.43 [95% CI=1.40-4.84] per quintile increase, p=0.004), calcium (OR=1.73 [95% CI=1.07-3.00] per quintile increase, p=0.034) and beta carotene (OR=2.01 [95% CI=1.06-4.18] per quintile increase, p=0.042), and lower potassium (OR=0.31 [95% CI=0.13-0.63] per quintile increase, p=0.003). Sensitivity analysis was performed by removing oxalate from the model and limiting the sample to patients aged 5-13 years, with similar results. CONCLUSIONS: In our cohort, higher dietary intake of calcium, sodium and beta carotene, and lower potassium intake were associated with pediatric urolithiasis. This is the first study using a detailed dietary survey to identify dietary risk factors for pediatric urolithiasis. Further research is warranted to delineate the mechanisms and to generate a lower risk diet profile for pediatric urolithiasis.

Top-Down versus Bottom-Up Approach in Children Presenting with Urinary Tract Infection: Comparative Effectiveness Analysis Using RIVUR and CUTIE Data.

PURPOSE: The initial imaging approach to children with urinary tract infection (UTI) is controversial. Along with renal/bladder ultrasound, some advocate voiding cystourethrogram (VCUG), ie a bottom-up approach, while others advocate dimercaptosuccinic acid (DMSA) scan, ie a top-down approach. Comparison of these approaches is challenging. In the RIVUR/CUTIE trials, however, all subjects underwent both VCUG and DMSA scan. Our objective was to perform a comparative effectiveness analysis of the bottom-up vs top-down approach. MATERIALS AND METHODS: We simulated 1,000 hypothetical sets of 500 children using RIVUR/CUTIE data. In the top-down approach, patients underwent initial DMSA scan, and only those with renal scarring underwent VCUG. In the bottom-up approach, the initial study was VCUG. We assumed all children with vesicoureteral reflux (VUR) received continuous antibiotic prophylaxis (CAP). Outcomes included recurrent UTI, number of VCUGs and CAP exposure. We assumed a 25% VUR prevalence in children with initial UTI with sensitivity analysis using 40% VUR prevalence. RESULTS: Median age of the original RIVUR/CUTIE cohort was 12 months. First DMSA scan was performed at a median of 8.2 weeks (IQR 5-11.8) after the index UTI. In the simulated cohort, slightly higher yet statistically significantly recurrent UTI was associated with the top-down compared with the bottom-up approach (24.4% vs 18.0%, p=0.045). On the other hand, the bottom-up approach resulted in more VCUG (100% vs 2.4%, p <0.001). Top-down resulted in fewer CAP-exposed patients (25% vs 0.4%, p <0.001) and lower overall CAP exposure (5 vs 162 days/person, p <0.001). Sensitivity analysis was performed with 40% VUR prevalence with similar results. CONCLUSIONS: The top-down approach was associated with slightly higher recurrent UTI. Compared to the bottom-up approach, it significantly reduced the need for VCUG and CAP.

Selecting Children with Vesicoureteral Reflux Who are Most Likely to Benefit from Antibiotic Prophylaxis: Application of Machine Learning to RIVUR.

PURPOSE: Continuous antibiotic prophylaxis reduces the risk of recurrent urinary tract infection by 50% in children with vesicoureteral reflux. However, there may be subgroups in whom continuous antibiotic prophylaxis could be used more selectively. We sought to develop a machine learning model to identify such subgroups. MATERIALS AND METHODS: We used RIVUR data, randomly split into train/test in a 4:1 ratio. Two models were developed to predict recurrent urinary tract infection risk in scenario with and without continuous antibiotic prophylaxis. The test set was then used to validate recurrent urinary tract infection events and the effectiveness of continuous antibiotic prophylaxis. Predicted probabilities of recurrent urinary tract infection were generated from each model. Continuous antibiotic prophylaxis was assigned at various cutoffs of recurrent urinary tract infection risk reduction to evaluate continuous antibiotic prophylaxis effectiveness. RESULTS: A total of 607 patients (558 female/49 male, median age 12 months) were included. Predictors included vesicoureteral reflux grade, serum creatinine, race/gender, prior urinary tract infection symptoms (fever/dysuria) and weight percentiles. The AUC of the prediction model of recurrent urinary tract infection (continuous antibiotic prophylaxis/placebo) was 0.82 (95% CI 0.74-0.87). Using 10% recurrent urinary tract infection risk reduction cutoff, minimal recurrent urinary tract infection per population level can be achieved by giving continuous antibiotic prophylaxis to 40% of patients with vesicoureteral reflux instead of everyone. In a test set (121), 51 patients had continuous antibiotic prophylaxis randomization consistent with model recommendation (continuous antibiotic prophylaxis if recurrent urinary tract infection risk reduction >10%). Recurrent urinary tract infection incidence was significantly lower among this group compared to those whose continuous antibiotic prophylaxis assignment differed from model suggestion (7.5% vs 19.4%, p=0.037). CONCLUSIONS: Our predictive model identifies patients with vesicoureteral reflux who are more likely to benefit from continuous antibiotic prophylaxis, which would allow more selective, personalized use of continuous antibiotic prophylaxis with maximal benefit, while minimizing use in those with least need.

Pattern recognition algorithm to identify detrusor overactivity on urodynamics.

AIMS: Detrusor overactivity (DO) of the bladder is a finding on urodynamic studies (UDS) that often correlates with lower urinary tract symptoms and drives management. However, UDS interpretation remains nonstandardized. We sought to develop a mathematical model to reliably identify DO in UDS. METHODS: We utilized UDS archive files for studies performed at our institution between 2013 and 2019. Raw tracings of vesical pressure, abdominal pressure, detrusor pressure, infused volume, and all annotations during UDS were obtained. Patients less than 1 year old, studies with calibration issues, or those with significant artifacts were excluded. In the training set, five representative DO patterns were identified. Candidate Pdet signal segments were matched to representative DO patterns. Manifold learning and dynamic time warping algorithms were used. Five-fold cross validation (CV) was used to evaluate the performance. RESULTS: A total of 799 UDS studies were included. The median age was 9 years (range, 1-33). There were 1,742 DO events that did not overlap with annotated artifacts (cough, cry, valsalva, movements). The AUC of the training sets from the five-fold CV was 0.84 ± 0.01. The five-fold CV leads to an overall accuracy 81.35%, and sensitivity and specificity of detecting DO events are 76.92% and 81.41%, respectively, in the testing set. CONCLUSIONS: Our predictive model using machine learning algorithms provides promising performance to facilitate automated identification of DO in UDS. This would allow for standardization and potentially more reliable UDS interpretation. Signal processing and machine learning interpretation of the other components of UDS are forthcoming.

Why Does Prevention of Recurrent Urinary Tract Infection not Result in Less Renal Scarring? A Deeper Dive into the RIVUR Trial.

PURPOSE: The RIVUR (Randomized Intervention for Children with Vesicoureteral Reflux) trial reported that antibiotic prophylaxis reduced recurrent urinary tract infection but antibiotic prophylaxis was not associated with decreased new renal scarring. However, the original reports did not assess the relationship among recurrent urinary tract infection, new renal scarring and antibiotic prophylaxis in detail. Therefore, we investigated the relationship among these issues. MATERIALS AND METHODS: We included subjects with dimercaptosuccinic acid scan within 6 months of enrollment and at least 1 followup dimercaptosuccinic acid scan from the RIVUR trial. The primary outcome was recurrent urinary tract infection associated new renal scarring, defined as recurrent urinary tract infection and new changes on dimercaptosuccinic acid scan. Due to a low number of events, propensity score was used to adjust for confounders. Multivariate logistic regression was fitted to investigate the associations between the covariates and the outcome. RESULTS: A total of 489 patients (91% female, mean age 20.3 months) were included in the study. Any new renal scarring was more common among those with recurrent urinary tract infection (OR 4.1, 95% CI 2.0-8.5, p <0.01) after adjusting for age, sex, index urinary tract infection, duplication, bowel bladder dysfunction and antibiotic prophylaxis. Recurrent urinary tract infection associated new renal scarring occurred in 5 of 244 (2%) patients on antibiotic prophylaxis and 13 of 245 (5%) on placebo. Compared to antibiotic prophylaxis, placebo was associated with a higher risk of recurrent urinary tract infection associated new renal scarring (OR 3.1, 95% CI 1.0-8.8, p=0.04) after adjusting for age, sex, race, index urinary tract infection, bowel bladder dysfunction, duplication, hydronephrosis, vesicoureteral reflux grade and baseline renal scarring. There were no differences in scar severity at final dimercaptosuccinic acid scan (p=0.88) or change from baseline (p=0.53) between antibiotic prophylaxis and placebo. CONCLUSIONS: Recurrent urinary tract infection was associated with new renal scarring in the RIVUR trial. When limited to recurrent urinary tract infection associated new renal scarring, antibiotic prophylaxis was associated with a decreased risk of this outcome. It remains unclear why new renal scarring developed in a proportion of subjects without recurrent urinary tract infection. The results should be carefully interpreted due to the inherent limitations.

Utility Estimation for Pediatric Vesicoureteral Reflux: Methodological Considerations Using an Online Survey Platform.

PURPOSE: The advent of online task distribution has opened a new avenue for efficiently gathering community perspectives needed for utility estimation. Methodological consensus for estimating pediatric utilities is lacking, with disagreement over whom to sample, what perspective to use (patient vs parent) and whether instrument induced anchoring bias is significant. We evaluated what methodological factors potentially impact utility estimates for vesicoureteral reflux. MATERIALS AND METHODS: Cross-sectional surveys using a time trade-off instrument were conducted via the Amazon Mechanical Turk® (https://www.mturk.com) online interface. Respondents were randomized to answer questions from child, parent or dyad perspectives on the utility of a vesicoureteral reflux health state and 1 of 3 "warm-up" scenarios (paralysis, common cold, none) before a vesicoureteral reflux scenario. Utility estimates and potential predictors were fitted to a generalized linear model to determine what factors most impacted utilities. RESULTS: A total of 1,627 responses were obtained. Mean respondent age was 34.9 years. Of the respondents 48% were female, 38% were married and 44% had children. Utility values were uninfluenced by child/personal vesicoureteral reflux/urinary tract infection history, income or race. Utilities were affected by perspective and were higher in the child group (34% lower in parent vs child, p <0.001, and 13% lower in dyad vs child, p <0.001). Vesicoureteral reflux utility was not significantly affected by the presence or type of time trade-off warm-up scenario (p = 0.17). CONCLUSIONS: Time trade-off perspective affects utilities when estimated via an online interface. However, utilities are unaffected by the presence, type or absence of warm-up scenarios. These findings could have significant methodological implications for future utility elicitations regarding other pediatric conditions.

Nationwide Trends and Variations in Urological Surgical Interventions and Renal Outcome in Patients with Spina Bifida.

PURPOSE: Bladder dysfunction in patients with spina bifida can lead to significant morbidity due to renal insufficiency. Indications for surgery vary among institutions and the impact is unclear. We examined trends and variations in urological interventions and chronic renal insufficiency in patients with spina bifida. MATERIALS AND METHODS: We reviewed NIS (Nationwide Inpatient Sample) for all patients with spina bifida treated from 1998 to 2011. We used ICD-9-CM codes to identify urological surgery and chronic renal insufficiency. We calculated the Spearman correlation coefficients between rates of spina bifida related bladder surgeries and rates of chronic renal insufficiency outcomes by state. Linear regression models were fitted to investigate the associations between rates of spina bifida related surgery and chronic renal insufficiency across treatment years. RESULTS: We identified 427,616 spina bifida hospital admissions. Mean patient age was 26 years and 56% of patients were female. Of the admissions 35,249 (8%) were for chronic renal insufficiency and 11,078 (3%) were for surgery. During the study period chronic renal insufficiency rates doubled from 6% to 12% and surgery rates decreased from 2.0% to 1.8%. There was a moderately weak inverse association between surgery and chronic renal insufficiency rates with time (r = -0.3, p = 0.06) and by state (r = -0.3, p = 0.04). On multivariate analysis higher rates of surgery were associated with the state in which the patient was treated (p <0.001), and with younger age (p <0.001) and hospital teaching status (p <0.001). In contrast, chronic renal insufficiency was not associated with spina bifida related surgery (p = 0.67). CONCLUSIONS: We observed a temporal and geographic trend toward decreasing urological surgery and increasing chronic renal insufficiency rates in spina bifida and a wide variation in urological surgical rates among states. Further study is needed to determine the factors behind these trends and variations in spina bifida management.

Outcomes of Shock Wave Lithotripsy and Ureteroscopy for Treatment of Pediatric Urolithiasis.

PURPOSE: Shock wave lithotripsy has been commonly used to treat children with renal and ureteral calculi but recently ureteroscopy has been used more frequently. We examined postoperative outcomes from these 2 modalities in children. MATERIALS AND METHODS: We reviewed linked inpatient, ambulatory surgery and emergency department data from 2007 to 2010 for 5 states to identify pediatric admissions for renal/ureteral calculi treated with shock wave lithotripsy or ureteroscopy. Unplanned readmissions, additional procedures and emergency room visits were extracted. Multivariate logistic regression using generalized estimating equations to adjust for hospital level clustering was performed. RESULTS: We identified 2,281 admissions (1,087 for shock wave lithotripsy and 1,194 for ureteroscopy). Ages of patients undergoing ureteroscopy and those undergoing shock wave lithotripsy were similar (median 17.0 years for both cohorts, p = 0.001) but patients were more likely to be female (63.4% vs 54.7%, p <0.0001), to be privately insured (69.8% vs 62.2%, p <0.0005) and to have a ureteral stone (81.0% vs 34.8%, p <0.0001). Patients undergoing ureteroscopy demonstrated a lower rate of additional stone related procedures within 12 months (13.6% vs 18.8%, p <0.0007) but a higher rate of readmissions (10.8% vs 6.3%, p <0.0002) and emergency room visits (7.9% vs 4.9%, p <0.0036) within 30 days postoperatively. On multivariable analysis patients undergoing ureteroscopy were nearly twice as likely to visit an emergency room within 30 days of the procedure (OR 1.97, p <0.001) and to be readmitted to inpatient services (OR 1.71, p <0.01). CONCLUSIONS: Ureteroscopy is now used more commonly than shock wave lithotripsy for initial pediatric stone intervention. Although repeat treatment rates did not differ between procedures, ureteroscopy patients were more likely to be seen at an emergency room or hospitalized within 30 days of the initial procedure.

Emergent care patterns in patients with spina bifida: a case-control study.

PURPOSE: Individuals with spina bifida are typically followed closely as outpatients by multidisciplinary teams. However, emergent care of these patients is not well defined. We describe patterns of emergent care in patients with spina bifida and healthy controls. MATERIALS AND METHODS: We reviewed Nationwide Emergency Department Sample data from 2006 to 2010. Subjects without spina bifida (controls) were selected from the sample using stratified random sampling and matched to each case by age, gender and treatment year at a 1:4 ratio. Missing emergency department charges were estimated by multiple imputation. Statistical analyses were performed to compare patterns of care among emergency department visits and charges. RESULTS: A total of 226,709 patients with spina bifida and 888,774 controls were identified. Mean age was 28.2 years, with 34.6% of patients being younger than 21. Patients with spina bifida were more likely than controls to have public insurance (63.7% vs 35.4%, p <0.001) and to be admitted to the hospital from the emergency department (37.0% vs 9.2%, p <0.001). Urinary tract infections were the single most common acute diagnosis in patients with spina bifida seen emergently (OR 8.7, p <0.001), followed by neurological issues (OR 2.0, p <0.001). Urological issues were responsible for 34% of total emergency department charges. Mean charges per encounter were significantly higher in spina bifida cases vs controls ($2,102 vs $1,650, p <0.001), as were overall charges for patients subsequently admitted from emergent care ($36,356 vs $29,498, p <0.001). CONCLUSIONS: Compared to controls, patients with spina bifida presenting emergently are more likely to have urological or neurosurgical problems, to undergo urological or neurosurgical procedures, to be admitted from the emergency department and to incur higher associated charges.

Hospital Surgical Volume and Associated Postoperative Complications of Pediatric Urological Surgery in the United States.

PURPOSE: Hospital and provider surgical volume have been increasingly linked to surgical outcomes. However, this topic has rarely been addressed in children. We investigated whether hospital surgical volume impacts complication rates in pediatric urology. MATERIALS AND METHODS: We retrospectively reviewed the Nationwide Inpatient Sample (1998 to 2011) for pediatric (18 years or younger) hospitalizations for urological procedures. We used ICD-9-CM codes to identify elective urological interventions and NSQIP® postoperative in hospital complications. Annual hospital surgical volume was calculated and dichotomized as high volume (90th percentile or above) or non-high volume (below 90th percentile). RESULTS: We identified 158,805 urological admissions (114,634 high volume and 44,171 non-high volume hospitals). Of the hospitals 75% recorded fewer than 5 major pediatric urology cases performed yearly. High volume hospitals showed treatment of significantly younger patients (mean 5.4 vs 9.6 years, p < 0.001) and were more likely to be teaching hospitals (93% vs 71%, p < 0.001). The overall rate of NSQIP identified postoperative complications was higher at non-high volume vs high volume hospitals (11.6% vs 9.3%, p = 0.003). After adjusting for confounding effects patients treated at non-high volume hospitals remained more likely to suffer multiple NSQIP tracked postoperative complications, including acute renal failure (OR 1.4, p = 0.04), urinary tract infection (OR 1.3, p = 0.01), postoperative respiratory complications (OR 1.5, p = 0.01), systemic sepsis (OR 2.0, p ≤ 0.001), postoperative bleeding (OR 2.5, p < 0.001) and in hospital death (OR 2.2, p = 0.007). CONCLUSIONS: Urological procedures performed in children at non-high volume hospitals were associated with an increased risk of in hospital, NSQIP identified postoperative complications, including a small but significant increase in postoperative mortality, mostly following nephrectomy and percutaneous nephrolithotomy.

Complications of surgical management of upper tract calculi in spina bifida patients: analysis of nationwide data.

PURPOSE: The management of upper urinary tract stones in patients with spina bifida is challenging but poorly described in the literature. We compared urolithiasis interventions and related complications in patients with spina bifida to those in other stone formers using a national database. MATERIALS AND METHODS: We retrospectively reviewed the NIS to identify hospital admissions for renal and ureteral stones from 1998 to 2011. We used ICD-9-CM codes to identify urological interventions, including shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy and ureteral stent placement. NSQIP data were used to identify postoperative complications. RESULTS: We identified 4,287,529 weighted stone hospital admissions, including 12,315 (0.3%) of patients with spina bifida. Compared to those without spina bifida the patients with spina bifida who had urolithiasis were significantly younger (mean age 34 vs 53 years), more likely to have public insurance (72% vs 44%) and renal vs ureteral calculi (81% vs 58%), and undergo percutaneous nephrolithotomy (27% vs 8%). After adjusting for age, insurance, comorbidity, treatment year, surgery type, stone location and hospital factors patients with spina bifida were more likely to have urinary tract infections (OR 2.5), urinary complications (OR 3.1), acute renal failure (OR 1.9), respiratory complications (OR 2.0), pneumonia (OR 1.5), respiratory insufficiency (OR 3.2), prolonged mechanical ventilation (OR 3.2), sepsis (OR 2.7), pulmonary embolism (OR 3.0), cardiac complications (OR 2.4) and bleeding (OR 1.6). CONCLUSIONS: Compared to those without spina bifida the patients with spina bifida who were hospitalized for urolithiasis were younger, and more likely to have renal stones and undergo percutaneous nephrolithotomy. Urolithiasis procedures in patients with spina bifida were associated with a significantly higher risk of in-hospital postoperative complications.

Estimating the nationwide, hospital based economic impact of pediatric urolithiasis.

PURPOSE: The incidence of urolithiasis is increasing in children and adolescents but the economic impact of this problem is unclear. We examined 2 large databases to estimate the nationwide economic impact of pediatric urolithiasis. MATERIALS AND METHODS: We analyzed the 2009 NEDS and KID, used ICD-9-CM codes to identify children 18 years or younger diagnosed with urolithiasis and abstracted demographic and charge data from each database. RESULTS: We identified 7,348 weighted inpatient discharges in KID and 33,038 emergency department weighted encounters in NEDS. Of the patients 32% and 36% were male, respectively. Inpatients were younger than those who presented to the ED (mean age 13.9 vs 15.7 years). Most patients had private insurance (52.9% to 57.2%) and the South was the most common geographic region (39.5% to 44.4%). The most common procedures were ureteral stent placement in 20.4% to 24.1% of cases, followed by ureteroscopy in 3.8% to 4.4%. Median charges per admission were $13,922 for a weighted total of $229 million per year. Median emergency department charges were $3,991 per encounter for a weighted total of $146 million per year. CONCLUSIONS: Each day in 2009 in the United States an estimated 20 children were hospitalized and 91 were treated in the emergency department for upper tract stones. A conservative estimate of 2009 annual charges related to pediatric urolithiasis in the United States is at least $375 million. This is likely a significant underestimate of the true economic burden of pediatric urolithiasis because it accounts for neither outpatient management nor indirect costs such as caregiver time away from work.

Efficacy of antibiotic prophylaxis in children with vesicoureteral reflux: systematic review and meta-analysis.

PURPOSE: Controversy exists regarding the use of continuous antibiotic prophylaxis vs observation in the management of children with vesicoureteral reflux. The reported effectiveness of continuous antibiotic prophylaxis in children with reflux varies widely. We determined whether the aggregated evidence supports use of continuous antibiotic prophylaxis in children with vesicoureteral reflux. MATERIALS AND METHODS: We searched the Cochrane Controlled Trials Register, clinicaltrials.gov, MEDLINE(®), EMBASE(®), Google Scholar and recently presented meeting abstracts for reports in any language. Bibliographies of included studies were then hand searched for any missed articles. The study protocol was prospectively registered at PROSPERO (No. CRD42014009639). Reports were assessed and data abstracted in duplicate, with differences resolved by consensus. Risk of bias was assessed using standardized instruments. RESULTS: We identified 1,547 studies, of which 8 are included in the meta-analysis. Pooled results demonstrated that continuous antibiotic prophylaxis significantly reduced the risk of recurrent febrile or symptomatic urinary tract infection (pooled OR 0.63, 95% CI 0.42-0.96) but, if urinary tract infection occurred, increased the risk of antibiotic resistant organism (pooled OR 8.75, 95% CI 3.52-21.73). A decrease in new renal scarring was not associated with continuous antibiotic prophylaxis use. Adverse events were similar between the 2 groups. Significant heterogeneity existed between studies (I(2) 50%, p = 0.03), specifically between those trials with significant risk of bias (eg unclear protocol descriptions and/or lack of blinding). CONCLUSIONS: Compared to no treatment, continuous antibiotic prophylaxis significantly reduced the risk of febrile and symptomatic urinary tract infections in children with vesicoureteral reflux, although it increased the risk of infection due to antibiotic resistant bacteria. Continuous antibiotic prophylaxis did not significantly impact the occurrence of new renal scarring or reported adverse events.

Use of nephron sparing surgery and impact on survival in children with Wilms tumor: a SEER analysis.

PURPOSE: Nephron sparing surgery is the standard of care for many adults with renal tumors and has been described in some children with Wilms tumor. However, beyond case series the data concerning nephron sparing surgery application and outcomes in patients with Wilms tumor are scarce. We examined nephron sparing surgery outcomes and factors associated with its application in children with Wilms tumor. MATERIALS AND METHODS: We retrospectively reviewed the 1998 to 2010 SEER database. We identified patients 18 years old or younger with Wilms tumor. Clinical, demographic and socioeconomic data were abstracted, and statistical analysis was performed using multivariate logistic regression (predicting use of nephron sparing surgery limited to unilateral tumors smaller than 15 cm) and Cox regression (predicting overall survival) models. RESULTS: We identified 876 boys and 956 girls with Wilms tumor (mean ± SD age 3.3 ± 2.9 years). Of these patients 114 (6.2%) underwent nephron sparing surgery (unilateral Wilms tumor in 74 and bilateral in 37). Median followup was 7.1 years. Regarding procedure choice, nephron sparing surgery was associated with unknown lymph node status (Nx vs N0, p <0.001) and smaller tumor size (p <0.001). Regarding survival, only age (HR 1.09, p = 0.002), race (HR 2.48, p = 0.002), stage (HR 2.99, p <0.001) and lymph node status (HR 2.17, p = 0.001) predicted decreased overall survival. Survival was not significantly different between children undergoing nephron sparing surgery and radical nephrectomy (HR 0.79, p = 0.58). CONCLUSIONS: In children with Wilms tumor included in the SEER database nephron sparing surgery has been infrequently performed. Nephron sparing surgery application is associated with smaller, bilateral tumors and with omission of lymphadenectomy. However, there are no evident differences in application of nephron sparing surgery based on demographic or socioeconomic factors. Despite lymph node under staging, overall survival is similar between patients undergoing nephron sparing surgery and radical nephrectomy.

A machine learning algorithm predicting risk of dilating VUR among infants with hydronephrosis using UTD classification.

BACKGROUNDS: Urinary Tract Dilation (UTD) classification has been designed to be a more objective grading system to evaluate antenatal and post-natal UTD. Due to unclear association between UTD classifications to specific anomalies such as vesico-ureteral reflux (VUR), management recommendations tend to be subjective. OBJECTIVE: We sought to develop a model to reliably predict VUR from early post-natal ultrasound. STUDY DESIGN: Radiology records from single institution were reviewed to identify infants aged 0-90 days undergoing early ultrasound for antenatal UTD. Medical records were reviewed to confirm diagnosis of VUR. Primary outcome defined as dilating (≥Gr3) VUR. Exclusion criteria include major congenital urologic anomalies (bilateral renal agenesis, horseshoe kidney, cross fused ectopia, exstrophy) as well as patients without VCUG. Data were split into training/testing sets by 4:1 ratio. Machine learning (ML) algorithm hyperparameters were tuned by the validation set. RESULTS: In total, 280 patients (540 renal units) were included in the study (73 % male). Median (IQR) age at ultrasound was 27 (18-38) days. 66 renal units were found to have ≥ grade 3 VUR. The final model included gender, ureteral dilation, parenchymal appearance, parenchymal thickness, central calyceal dilation. The model predicted VUR with AUC at 0.81(0.73-0.88) on out-of-sample testing data. Model is shown in the figure. DISCUSSION: We developed a ML model that can predict dilating VUR among patients with hydronephrosis in early ultrasound. The study is limited by the retrospective and single institutional nature of data source. This is one of the first studies demonstrating high performance for future diagnosis prediction in early hydronephrosis cohort. CONCLUSIONS: By predicting dilating VUR, our predictive model using machine learning algorithm provides promising performance to facilitate individualized management of children with prenatal hydronephrosis, and identify those most likely to benefit from VCUG. This would allow more selective use of this test, increasing the yield while also minimizing overutilization.

Self-adjusted Nitrous Oxide During Urodynamic Studies Reduces Patient Pain Without Compromising Study Quality: A Randomized Controlled Trial.

Background and objective: A urodynamic study (UDS) is a routine clinic procedure that can cause significant discomfort for certain patients, with no satisfactory analgesic alternatives currently available. Our aim was to evaluate the effectiveness of low-dose self-adjusted nitrous oxide (SANO), titrated to the patient's desired effect, on standard metrics for bladder function and on patient-reported pain and anxiety. Methods: We conducted a single-institution, double-blind, randomized crossover trial in adults undergoing UDS. Each patient underwent two consecutive UDS runs, randomized to receive oxygen during the first run followed by SANO during the second run, or vice versa. UDS outcomes (capacity, detrusor strength, residual volume) and patient subjective outcomes (Visual Analog Scale for pain and anxiety, operator assessment of verbal feedback) were compared between the two runs. Secondary analyses were performed to compare outcomes during the first UDS run and adjust for treatment order. A paired Wilcoxon signed rank-sum test and McNemar's χ2 test were used to compare continuous and categorical variables, respectively. Adverse events were recorded. Key findings and limitations: Nineteen patients were randomized (10 to oxygen for the first run, 9 to SANO for the first run). UDS outcomes did not differ between the two arms. Patients reported significantly less pain during the SANO run than during the oxygen run (p = 0.046). Verbal feedback was significantly better with SANO (p = 0.001). Most patients (15/19, 79%) stated that they would prefer to receive SANO during future UDS. There were no significant complications. Conclusions and clinical implications: SANO oxide is a safe and effective means of preserving standard adult UDS metrics while significantly reducing patient-reported pain. Patient summary: Urodynamic tests (UDS) for evaluation of lower urinary tract symptoms can cause discomfort and pain. Our study shows that nitrous oxide gas self-adjusted by patients had no effect on UDS test outcomes or on verbal feedback during the procedure, and reduced discomfort and pain in comparison to oxygen. Nitrous oxide may an attractive option for patients who are reluctant to undergo UDS.