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Allopurinol is a commonly prescribed agent in the urologic population for the prevention of urinary stones. Although generally well-tolerated, several serious potential side effects can occur with its use. Allopurinol hypersensitivity syndrome (AHS), in particular, is a relatively rare but potentially life-threatening complication. With the observed increase in urinary stone disease, especially those of uric acid composition, it is likely that the use of allopurinol will increase. Urologists play an important role in the assessment and medical management of patients with urinary stones, thus a greater awareness of the potential adverse events associated with allopurinol use, especially AHS, is important, as well as strategies that can minimize such risks. Herein, we review the potential adverse effects of allopurinol. In addition, the results of a comprehensive review of the current literature on AHS will be presented, highlighting those patients at highest risk, reviewing the genetic susceptibility testing currently available, and providing guidance on best practices when allopurinol therapy is being considered. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Urolithiasis represents a leading cause of emergency department (ED) presentation nationally, affecting approximately 10% of Americans. However, most patients require neither hospital admission nor surgical intervention. This study investigates patient and facility factors associated with potentially avoidable ED visits and their economic consequences. STUDY DESIGN: Retrospective analysis. METHODS: Patients presenting to the ED for index urolithiasis events were selected using Florida and New York all-payer data from the 2016 Healthcare Cost and Utilization Project state databases. Avoidable visits were defined as subsequent ED encounters following initial ED presentation that did not result in intervention, admission, or referral to an acute care facility. Utilizing multivariable logistic and linear regression, researchers discerned patient and facility factors predictive of avoidable ED presentations and associated costs. RESULTS: Of the 167,102 ED encounters for urolithiasis, 7.9% were potentially avoidable, totaling $94,702,972 in potential yearly cost savings. Mean encounter-level costs were higher for unavoidable vs avoidable visits ($5885 vs $2098). In contrast, mean episode-based costs were similar for avoidable and unavoidable episodes ($7200 vs $7284). Receiving care in small metropolitan (vs large metropolitan) communities was associated with potentially avoidable visits, whereas increased comorbidities and Hispanic ethnicity were protective against avoidable visits. CONCLUSIONS: The incidence of ED use for subsequent urolithiasis care reveals opportunity for enhanced outpatient availability to reduce hospital-based costs. Several nonclinical factors are associated with potentially avoidable ED visits for urolithiasis, which, if appropriately targeted, may represent an opportunity to reduce health care spending without compromising the quality of care delivery. [ABSTRACT FROM AUTHOR]

In the past two decades, major breakthroughs that improve our understanding of the pathophysiology and therapy of kidney stones (KS) have been lacking. The disease continues to be challenging for patients, physicians, and healthcare systems alike. In this context, epidemiological studies are striving to elucidate the worldwide changes in the patterns and the burden of the disease and identify modifiable risk factors that contribute to the development of kidney stones. Our expanding knowledge of the epidemiology of kidney stones is of paramount importance and largely upgrades the modern management of the disease. In this paper, we review the variables affecting prevalence and incidence, including age, gender, race, ethnicity, occupation, climate, geography, systemic diseases, diabetes, vascular disease, chronic kidney disease, and dietary risk factors relevant to kidney stones. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the effect of pregnancy on the clinical presentation, inpatient procedure rates, and length of hospital stay, on women with urolithiasis. Materials and methods We carried out a matched cohort study using the United States’ Healthcare Cost and Utilization Project-Nationwide Inpatient Sample database from 1999 to 2015. Pregnant women with urolithiasis were compared to age-matched non-pregnant women (1:1) with urolithiasis. Baseline clinical characteristics were compared between the two cohorts and the effect of pregnancy on select inpatient procedural and clinical outcomes was evaluated using conditional logistic regression models. Results There were 42,113 pregnant patients diagnosed with urolithiasis during the study period. It was observed that pregnant patients were less likely to present with classic clinical symptoms of urinary tract stones, such as flank pain, OR 0.63, 95% CI 0.56–0.70, and fever, 0.22 (0.16–0.30), but tended to have longer hospital stays. The pregnant patients were less commonly affected by infectious conditions, namely urinary tract infections, 0.56 (0.53–0.59), sepsis, 0.17 (0.14–0.20), and pyelonephritis, 0.34 (0.36–0.44). Invasive and surgical procedures were less commonly performed in pregnant women. Conclusions Pregnant women admitted with urolithiasis appear to be less symptomatic with fewer interventions and complications than non-pregnant women with urolithiasis. [ABSTRACT FROM AUTHOR]

To identify the characteristics of patients with sepsis or acute pyelonephritis (APN) combined with ureteral calculi and to analyze the risk factors in its causation. Methods: We included patients with sepsis or APN caused by ureteral calculi who received treatment in the United States from January 2003 to December 2017 using the Optum® deidentified Clinformatics® Datamart. Demographic factors and risk factors for the receipt of sepsis or APN were subsequently analyzed for statistical significance. Results: Of 467,502 urinary stone patients, age-matched multivariate analysis revealed that a history of urinary tract infection (OR 11.31, 95% CI 10.68–11.99, p < 0.0001) and female gender (OR 2.73, 95% CI 2.62–2.84, p < 0.0001) were significantly related to an increased risk of sepsis or APN. Conversely, a previous past medical history of urolithiasis (OR 0.91, 95% CI 0.87–0.95, p < 0.0001) and cancer (OR 0.91, 95% CI 0.87–0.95, p < 0.0001) were associated with a decreased risk of sepsis or APN. With regards to comorbidities, when more than one comorbidity was present, there was an additive effect with higher OR point estimates, rising to 11.31 (10.68–11.99) when three or more comorbidities present. History of urinary tract infection and female gender are risk factors for sepsis or APN in patients with ureteral calculi. Conclusions: This large national cohort reveals the characteristics of sepsis or APN combined with ureteral stone and provides an important baseline for the treatment of urolithiasis in the future. [ABSTRACT FROM AUTHOR]

This article provides information to assist practitioners in the diagnosis, medical, and surgical management of obstructive urolithiasis in miniature pigs. The article focuses primarily on pigs managed as pets because production swine rarely undergo intensive treatment for urolithiasis. As much as possible, the information in this article is based on published literature, butgiven the limited numberof publicationsaddressing obstructive urolithiasis in pigs, some information is based on the authors' clinical experience. Medical and surgical management of obstructive urolithiasis of pigs is often similar to management in ruminant and small animal species, but differences in swine anatomy, handling, and temperament create unique challenges. Pigs tend to be more difficult to restrain and examine than other livestock and often require heavy sedation or anesthesia to facilitate physical examination and basic diagnostic procedures. Because pigs are monogastrics, some oral treatments used in small animals may be used effectively in pigs. Clinicians should follow AMDUCA and consultthe Food Animal Residue Avoidance Databank priorto extralabel drug use because pet pigs are still considered a major food-producing species in the United States. [ABSTRACT FROM AUTHOR]

Objective: To analyze the National Hospital Ambulatory Medical Care Survey (NHAMCS) database to determine geographic and temporal trends, as well as variables associated with the likelihood of receiving an opioid prescription for urolithiasis in United States (US) emergency departments (EDs).Materials and Methods: All ED visits for urolithiasis between 2006 and 2018 in the NHAMCS database were analyzed. Age, race/ethnicity, insurance status, ED provider credentials, geographic region, and urban vs rural hospital status were extracted. Linear regression was used to examine overall/regional trends in opioid prescriptions over time. Logistic regression was used to estimate factors associated with higher odds of receiving opioids.Results: Fourteen million visits were analyzed, of which, 79.1% (11.0 million) received an opioid prescription. From 2014 to 2018 there was a decline of 3.65%/year of the proportion of visits receiving an opioid prescription (R2 = 0.86, P = .008). Non-Hispanic Black race was associated with a lower chance of receiving opioid prescription (OR = 0.57, P = .02) compared to Non-Hispanic Whites (NHW). Midwestern hospitals had higher odds of opioid prescription compared to the Northeast (OR = 2.05, P = .006). Rural hospitals had lower odds of opioid prescription compared to urban hospitals (OR = 0.62, P = .02).Conclusion: Opioid prescriptions for patients presenting with urolithiasis to the ED have steadily declined from 2014 to 2018, except in the Midwest. NHW race, Midwest region, and urban EDs increase the likelihood of receiving opioids. Continued efforts encouraging non-opioid alternatives for urolithiasis are essential, specifically in Midwestern EDs, to mitigate the ongoing opioid epidemic in the US. [ABSTRACT FROM AUTHOR]

Background: Severe acute pain is still commonly treated with opioid analgesics in the United States, but this practice could prolong the duration of pain.Objectives: Estimate the risk of experiencing persistent pain after opioid analgesic use after emergency department (ED) discharge among patients with suspected urolithiasis.Methods: We analyzed data collected for a longitudinal, multicenter clinical trial of ED patients with suspected urolithiasis. We constructed multilevel models to estimate the odds ratios (ORs) of reporting pain at 3, 7, 30, or 90 days after ED discharge, using multiple imputation to account for missing outcome data. We controlled for clinical, demographic, and institutional factors and used weighting to account for the propensity to be prescribed an opioid analgesic at ED discharge.Results: Among 2413 adult ED patients with suspected urolithiasis, 62% reported persistent pain 3 days after discharge. Participants prescribed an opioid analgesic at discharge were OR 2.51 (95% confidence interval [CI] 1.82-3.46) more likely to report persistent pain than those without a prescription. Those who reported using opioid analgesics 3 days after discharge were OR 2.24 (95% CI 1.77-2.84) more likely to report pain at day 7 than those not using opioid analgesics at day 3, and those using opioid analgesics at day 30 had OR 3.25 (95% CI 1.96-5.40) greater odds of pain at day 90.Conclusions: Opioid analgesic prescription doubled the odds of persistent pain among ED patients with suspected urolithiasis. Limiting opioid analgesic prescribing at ED discharge for these patients might prevent persistent pain in addition to limiting access to these medications. [ABSTRACT FROM AUTHOR]

Objective: To report the first case series of ureterorenoscopy in North America using the High Power Super Pulse Thulium Fiber Laser for the treatment of upper urinary tract stones.Methods: After Institutional Review Board approval, a multicentric retrospective chart review of patients treated with the High Power Super Pulse Thulium Fiber Laser from October 2019 to March 2020 was conducted. Basic demographic information, pre-operative, and peri-operative data were recorded.Results: Seventy-six patients were included with a mean age of 60.9 ± 13.3 years. 118 stones were treated including 32 within the ureter, 49 in the lower pole, 37 in mid or upper poles. Dusting technique was commonly used (67.1%) with pulse frequencies up to 2400 Hz. Mean operative time was 59.4 ± 31.5 minutes. Mean laser time and total laser energy were 10.8 ± 14.1 minutes and 12.5 ± 19.1 KJ, respectively. Intraoperative complications were limited to 7 grade 1, 3 grade 2, and 1 grade 3 ureteral injuries and one case of renal collecting system bleeding that was adequately managed with laser coagulation settings (1J-20Hz).Conclusion: This initial case series in North America of the High Power Super Pulse Thulium Fiber Laser is promising for the treatment of urolithiasis. Sub-200 μm fibers and dusting settings up to 2400 Hz were utilized successfully. No specific complications related to use of the laser were seen. [ABSTRACT FROM AUTHOR]

Purpose: Malignant extrinsic ureteral obstruction (MEUO) is a challenging clinical problem. Many factors weigh into the decision to proceed with retrograde ureteral stent (RUS), nephrostomy tube (NT), or observation; however, there is no consensus for the optimal approach. The objective of this study was twofold. First, to determine practice patterns by correlating patient, hospital, and disease characteristics to manage MEUO; second, to describe treatment trends of MEUO over time. Materials and Methods: Using the National Inpatient Sample 2010–2015, we abstracted all adults with diagnoses of hydronephrosis and concurrent metastasis or lymphoma, excluding any record with a diagnosis of urinary tract stone. Multinomial regression assessed predictors of undergoing no decompression, stenting, or nephrostomy. Quarterly trends and annual percentage change of MEUO prevalence and percentage decompressed with stent vs nephrostomy were calculated. Results: There were an estimated 238,500 cases of MEUO from 2010 to 2015, of which 18.0% underwent decompression with RUS and 11.4% NT. On multinomial regression, prostate (odds ratio [OR] 1.5), bladder (1.6), cervical (1.6) cancer, academic hospitals (1.4), and acute kidney injury were among factors that most significantly increased odds of undergoing NT. Factors that significantly increased odds of undergoing RUS included colon (OR 1.4), rectal/anal (1.3), ovarian (1.2) cancer, Midwest (vs northeast) hospitals (1.4), and female gender (1.4), whereas decreased odds of RUS were associated with bladder cancer (0.7), nonwhite race (0.8), and weekend admission (0.8). While MEUO prevalence has been increasing on an average of 2.9%/year, decompression rates have been decreasing, driven solely by a decrease in RUS of 3.8%/year on average. Conclusions: There is substantial variation in approach for MEUO among patient, hospital, and disease types, with an overall decline in stenting compared with steady nephrostomy use. Further investigation into best approaches for certain patient characteristics and disease types is needed to standardize care and reduce disparities. [ABSTRACT FROM AUTHOR]

Objective: To measure the incidence of persistent opioid use following ureteroscopy (URS). Over 100 Americans die every day from opioid overdose. Recent studies suggest that many opioid addictions surface after surgery.Methods: Using claims data, we identified adults who underwent outpatient URS for treatment of upper tract stones between January 2008 and December 2016 and filled an opioid prescription attributable to URS. We then measured the rate of new persistent opioid use-defined as continued use of opioids 91-180 days after URS among those who were previously opioid-naive. Finally, we fit multivariable models to assess whether new persistent opioid use was associated with the amount of opioid prescribed at the time of URS.Results: In total, 27,740 patients underwent outpatient URS, 51.2% of whom were opioid-naïve. Nearly 1 in 16 (6.2%) opioid-naïve patients developed new persistent opioid use after URS. Six months following surgery, beneficiaries with new persistent opioid use continued to fill prescriptions with daily doses of 4.2 oral morphine equivalents. Adjusting for measured sociodemographic and clinical differences, patients in the highest tercile of opioids prescribed at the time of URS had 69% higher odds of new persistent opioid use compared to those in the lowest tercile (odds ratio, 1.69; 95% CI, 1.41-2.03).Conclusion: Nearly 1 in 16 opioid-naive patients develop new persistent opioid use after URS. New persistent opioid use is associated with the amount of opioid prescribed at the time of URS. Given these findings, urologists should re-evaluate their post-URS opioid prescribing patterns. [ABSTRACT FROM AUTHOR]

Objective: To determine social factors associated with advanced stone disease (defined as unilateral stone burden >2 cm) at time of presentation to a regional stone referral center. Little is known about social determinants of urolithiasis. We hypothesize that socioeconomic factors impact kidney stone severity at intake to referral centers.Methods: A retrospective review of the prospectively collected data from the Registry for Stones of the Kidney and Ureter from 2015 to 2018 was conducted to evaluate patient characteristics predictive of having a large (>2 cm) unilateral kidney stone. Data on patient age, gender, body mass index, diabetes, race, language, education level, infection, distance, income, referring regional urologist density, American Society of Anesthesiologists score, and stone analysis were evaluated.Results: Complete imaging and patient variable data was present in 650 of 1142 patients including 197 patients with unilateral stone burden >2 cm. On multivariate analysis, obesity, lower education level, increased distance from the referral center, and symptoms of infection predicted for unilateral stone burden greater than 2 cm. Among 191 patients with stone analysis data present, stone type, income, and urologist density predicted for unilateral stone burden greater than 2 cm.Conclusion: In addition to known biological risk factors, patients with lower education levels and from regions of lower mean income were found to be more likely to present to our tertiary care center with stone burden greater than 2 cm. More research is needed to elucidate the social and societal determinants of advanced stone disease and the impact this has on population costs for stone treatment. [ABSTRACT FROM AUTHOR]

Introduction: Calculous nephrectomy was a mainstay of treatment of complex upper tract stone disease up until the 1970s, but data on its contemporary utilization in the current era of rising rates of stone disease are lacking. We characterized the nationwide utilization and outcomes for calculous nephrectomy in the United States. Patients and Methods: The National/Nationwide Inpatient Sample databases for 2001 to 2014 were queried for adults with a principal diagnosis of upper urinary tract calculi (UUTCs), who underwent nephrectomy as well as other inpatient surgeries for UUTCs. Per-population trend in utilization of calculous nephrectomy was analyzed using negative binomial regression. The proportion of calculous nephrectomy as a fraction of all inpatient surgical procedures for UUTCs was analyzed using the Cochran–Armitage test. Patient demographics, hospital characteristics, perioperative outcomes, and complications were analyzed using appropriate statistical tests. Results: Of almost 1.42 million inpatient UUTC procedures performed over the study period, 9232 (0.65%) were calculous nephrectomies. Per-population utilization rate for calculous nephrectomy decreased significantly over time (incidence rate ratio = 0.82; 95% confidence interval = 0.73–0.91, p < 0.001). The proportion of calculous nephrectomy as a fraction of all inpatient surgical procedures for UUTC also decreased significantly over time (p < 0.0001). Majority of the procedures were performed in females, in urban teaching hospitals, and in the Southern United States. The overall complication rate was 38.3%, most commonly hemorrhage requiring transfusion (15.6%). Older age, female gender, and nonprivate insurance or lack of insurance were significant predictors of increased risk of complications, whereas hospitalization in urban hospitals was a predictor of lower risk. Conclusions: Despite increasing prevalence of stone disease in the United States in the contemporary era, utilization of calculous nephrectomy is low and is declining. Inpatient complication rates are moderately high and influenced by patient sociodemographic and hospital characteristics. [ABSTRACT FROM AUTHOR]

Objective: To examine the recent epidemiology of pediatric urinary stone disease (USD) in the United States.Methods: We utilized the 2004-2016 Optum© Clinformatics® Data Mart database, a de-identified adjudicated administrative health claims database that includes 15-18 million individuals covered annually by commercial insurance in all 50 US states. The analysis included 12,739,125 children aged 0-18 years. We calculated annual rates of USD, ambulatory visits, and procedures, and the prevalence of prescription fills.Results: The 2005-2016 USD rate was 59.5 cases per 100,000 person-years. The annual rate rose gradually from 2005 to a peak of 65.2 cases per 100,000 person-years in 2011. The USD rate increased with increasing age, and was highest among females compared to males, non-Hispanic Whites compared to other race/ethnic groups, and those residing in the South compared to other geographic regions. The overall 2005-2016 rate in the 120 days following a USD episode was 1.9 for ambulatory visits, 0.24 for surgical procedures, and 1.1 for imaging procedures. Ureteroscopy was the most common surgical procedure and CT scan was the most common imaging procedures, although ultrasound utilization increased over time. Medications were filled in 46.9% of cases, and use was lowest among males (43.1%), Asians (34.8%), and in the Northeast (34.3%). Opiate agonists were the most prevalent prescription (39.9%).Conclusion: Our study provides one of the most comprehensive examinations of pediatric USD to date, demonstrating shifting rates and treatment patterns over time, as well as differences by age, gender, race/ethnicity, and geographic region. [ABSTRACT FROM AUTHOR]

Introduction: We sought to evaluate population-based cost variations and predictors of outlier costs for percutaneous nephrolithotomy (PCNL) in the U.S. Methods: Using the Premier Healthcare Database, we identified all patients diagnosed with kidney/ureter calculus who underwent PCNL from 2003--2015. We evaluated 90-day direct hospital costs, defining high- and low-cost surgery as those >90th and <10th percentile, respectively. We constructed a multilevel, hierarchical regression model and calculated the pseudo-R² of each variable, which translates to the percentage variability contributed by that variable on 90-day direct hospital costs. Results: A total of 114 581 patients underwent PCNL during the 12-year study period. Mean cost in the low-cost group was $5787 (95% confidence interval [CI] 5716--5856) vs. $38 590 (95% CI 37 357--39 923) in the high-cost group. Cost variations were sub- -39 923) in the high-cost group. Cost variations were sub- 39 923) in the high-cost group. Cost variations were substantially impacted by patient (63.7%) and surgical (18.5%) characteristics and less so by hospital characteristics (3.9%). Significant predictors of high costs included more comorbidities (≥2 vs. 0: odds ratio [OR] 1.81; p=0.01) and hospital region (Northeast vs. Midwest: OR 2.04; p=0.03). Predictors of low cost were hospital bed size of 300--499 beds (OR 1.35; p<0.01) and urban hospitals (OR 2.77; p=0.01). Factors less likely to be associated with low-cost PCNL were more comorbidities (Charlson Comorbidity Index [CCI] ≥2: OR 0.69; p<0.0001), larger hospitals (OR 0.61; p=0.01), and teaching hospitals (OR 0.33; p<0.0001). Conclusions: Our contemporary analysis demonstrates that patient and surgical characteristics had a significant effect on costs associated with PCNL. Poor comorbidity status contributed to high costs, highlighting the importance of patient selection. [ABSTRACT FROM AUTHOR]

Some regions are known to have an increased burden of urolithiasis. Urolithiasis is known to be affected by weather patterns, particularly high ambient temperatures. To identify geographic differences in risk factors, we compared metabolic information for 1254 patients in two geographically distinct regions, New York and Florida, with per sample adjustment for ambient weather. We observed that patients in New York were more likely to have low urine volume, but also lower total urinary calcium (168 vs 216 mg, p = 0.005), urate (376 vs 678 mg, p < 0.001), and phosphate (0.8 vs 0.9 g, p 0.007). Temperature was a predictor of urine pH ( B = −0.07, p = 0.024). Geographic region was a predictive factor ( p < 0.01) for urine calcium, volume, serum bicarbonate, and anion gap. Increased anion gap and serum HCO were also predicted by temperature ( B = 0.065, p = 0.035). Interestingly, urine volume was not affected by temperature. Our finding that temperature is a determining factor of urine pH and anion gap may help to explain the finding that hot weather is associated with increases in urolithiasis. Anion gap has also been previously associated with poor health measures and represents an interesting target for future research. Geographic location may independently contribute to urine composition, through regional diets, sun exposure, and groundwater. This study highlights the impact geographic location plays in determining risk factors for stone disease and the value of regional knowledge to the treating physician in preventing stone disease. [ABSTRACT FROM AUTHOR]

The prevalence of urinary stones in the United States has been described as 1 in 11 persons reporting a history of stones. Imaging plays a crucial role in diagnosis, management, and follow-up for these patients and imaging technology over the last 100 years has advanced as the disease prevalence has increased. CT remains the gold standard for imaging urolithiasis and changes in this technology, with the addition of multidetector CT and dual-energy CT, as well as the changes in utilization of CT, have decreased the radiation dose encountered by patients and allowed for improved stone detection. The use of digital tomography has been introduced for follow-up of recurrent stone formers offering the potential to lower radiation exposure over the course of a patient's lifelong treatment. However, there is still a demand for improved imaging techniques to detect smaller stones and stones in larger patients at lower radiation doses as well as the continued need for the judicious use of all imaging modalities for healthcare cost containment and patient safety. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to compare ultrasonography (US) and low-dose computed tomography (LDCT) for diagnosing pediatric urolithiasis in the emergency department. Materials and Methods: This retrospective study was approved by our institutional ethics committee, and informed consent was waived. From March 2016 to March 2017, 100 consecutive patients met the selection criteria and were enrolled in the study. Patients were randomly selected in a 1:1 ratio and were allocated to one of the following two imaging groups: US or abdominal LDCT. LDCT examinations were performed using a 320-detector row CT Radiation dose analysis was performed using Radimetrics. US examinations were performed using the Aplio 500 ultrasound system. The presence of urolithiasis, anatomical location of urolithiasis, and measurements of renal stones were evaluated and recorded. Results: There were statistically significant differences between US and standard-dose CT (SDCT) with respect to the diagnosis of urolithiasis, anatomical location of urolithiasis, and measurements of renal stones (p<0.001, p=0.005, and p=0.03, respectively). The mean effective radiation dose of LDCT was 1.44±0.34 mSv and that of SDCT was calculated to be 4.36±1.33 mSv. There was no statistically significant difference between LDCT and SDCT with regard to the diagnosis of urolithiasis, anatomical location of urolithiasis and measurements of renal stones (p=1 for all). The diagnostic accuracy of US and LDCT was 0.68 and 1.0, respectively. Conclusion: Low-dose computed tomography had 1/3 SDCT radiation dose, and LDCT and SDCT accurately diagnosed pediatric urolithiasis in the emergency department. US had a lower accuracy than SDCT and LDCT for diagnosing pediatric urolithiasis in the emergency department. LDCT can be an alternative for SDCT for diagnosing pediatric urolithiasis. [ABSTRACT FROM AUTHOR]

Objective: To study brushite stone formers (BSFs) change in renal function and overall risk of progression to chronic kidney disease (CKD) over time.Materials and Methods: A retrospective review of all patients with urolithiasis on stone analysis was performed from 1995 to 2003. Stones were classified as brushite if they had at least 10% brushite composition on analysis. Patients with a minimum of 6 years of clinical follow-up were included in the study. BSFs were matched 1:3 to idiopathic calcium oxalate stone formers (CaOx SF) over the same time period. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease equation. CKD was classified according to the National Kidney Foundation definition, with grade 3 defined as <60 mL/min/1.73 m2.Results: We identified 20 BSFs who met the inclusion criteria and matched to 60 CaOx SFs. Pure brushite stones were identified in 13 (65%) patients and 17 (85%) had >50% brushite composition. The median patient age (48 vs 47 years, P = .82) and baseline eGFR were not different between BSF and CaOx SF (74 vs 69 mL/min/1.73 m2, P = .68). No patients had stage IV or higher CKD in either group. At median follow-up of 13.6 years, both eGFR (78 vs 74 mL/min/1.73 m2, P = .61) and change in eGFR (0.31 vs 3.2 mL/min/1.73 m2, P = .92) were similar between groups despite the BSF having a higher stone recurrence rate (80% vs 42%, P = .003). No brushite patients experienced a change in CKD stage.Conclusion: BSFs were not shown to be at increased clinical risk of CKD compared with CaOx SFs at long-term follow-up despite more frequent stone recurrence. [ABSTRACT FROM AUTHOR]

Objective: To identify longitudinal trends of economic impact and resource utilization for management of pediatric urolithiasis using national databases.Methods: We analyzed the 2006-2012 Nationwide Emergency Department Sample and Nationwide Inpatient Sample. We used ICD-9 (International Classification of Diseases) codes to identify patients (≤18 years) diagnosed with urolithiasis. Diagnostic imaging and surgeries were identified using ICD-9 and Current Procedural Technology codes. We abstracted demographic, imaging, procedure, and charge data. Weighted descriptive statistics were calculated to describe the population's demographics and economic expenditures by clinical setting and year.Results: In total, 45,333 inpatient admissions (68% females) and 234,559 emergency department encounters (63% females) were identified. Most patients (84%) were teenagers and the southern region of the United States was the most common geographic region for all encounters (44%). There was no significant trend in number of urolithiasis encounters over the period studied. Utilization of all imaging techniques increased; in particular, computed tomography was used in 23% of encounters in 2006 and 40% in 2012 (P < .0001). The mean charge per emergency department visit increased by 60% from $3645 in 2006 to $5827 in 2012 (P < .0001). The mean charge increased for inpatient admissions by 102%, from $16,399 in 2006 to $33,205 in 2012 (P < .0001). Total charges increased 72% over the study period from $230 million in 2006 to $395 million in 2012 (P < .0001), outpacing medical inflation over the same period.Conclusion: Charges for pediatric urolithiasis management increased by 65% from 2006 to 2012 despite stable frequency of patient encounters. The utilization of computerized tomography in pediatric urolithiasis increased as well. [ABSTRACT FROM AUTHOR]

Objective: To describe guideline adherence for patients with suspected upper tract stones.Patients and Methods: We performed a cross-sectional analysis of visits recorded by the National Hospital Ambulatory Medical Care Survey (emergency department [ED] component) in 2007-2010 (most recent data). We assessed adherence to clinical guidelines for diagnostic laboratory testing, imaging, and pharmacologic therapy. Multivariable regression models controlled for important covariates.Results: An estimated 4,956,444 ED visits for patients with suspected kidney stones occurred during the study period. Guideline adherence was highest for diagnostic imaging, with 3,122,229 (63%) visits providing optimal imaging. Complete guideline-based laboratory testing occurred in only 2 of every 5 visits. Pharmacologic therapy to facilitate stone passage was prescribed during only 17% of eligible visits. In multivariable analysis of guideline adherence, we found little variation by patient, provider, or facility characteristics.Conclusion: Guideline-recommended care was absent from a substantial proportion of acute care visits for patients with suspected kidney stones. These failures of care delivery likely increase costs and temporary disability. Targeted interventions to improve guideline adherence should be designed and evaluated to improve care for patients with symptomatic kidney stones. [ABSTRACT FROM AUTHOR]

Objective To assess the efficacy of ultrasonography (US) for the detection of ureteral stone using non–contrast-enhanced computed tomography (NCCT) as a standard reference. Materials and Methods From January 2009 to September 2011, 428 patients underwent both NCCT and US on the same day. The sensitivity and specificity of US to detect ureteral stone was evaluated. The detection rates using US imaging were examined according to location and stone size. The sizes of stones determined in the longest axis of NCCT and US were compared. We also performed group classification based on size to examine whether stone sizes measured by NCCT and US were similar. Moreover, the factors that may affect the detection of ureteral stone by US were analyzed. Results Out of 856 ureters, NCCT could detect 171 stones in 169 patients, whereas US could detect 98 stones, yielding a sensitivity of 57.3% and a specificity of 97.5%. Expectedly, detection rate of US increased with stone size but was lower for distal ureter. With hydronephrosis, the sensitivity of US improved from 57.3% to 81.3%. Stone sizes measured by US correlated positively with those by computed tomography, and were concordant with those of NCCT in 68 of 98 patients (69.4%). Interestingly, stone size and the presence of hydronephrosis were factors that independently affected ureteral stone detection by US. Conclusion These results indicate that US may be useful as an initial imaging modality for detecting ureteral stone. [ABSTRACT FROM AUTHOR]

Abstract: Calcium oxalate urolithiasis results from the formation of aggregates of calcium salts in the urinary tract. Difficulties associated with effectively treating calcium oxalate urolithiasis and the proportional increase in the prevalence of calcium oxalate uroliths relative to other urolith types over the last 2 decades has increased the concern of clinicians about this disease. To determine factors associated with the development of calcium oxalate urolithiasis in dogs evaluated at general care veterinary hospitals in the United States, a retrospective case-control study was performed. A national electronic database of medical records of all dogs evaluated between October 1, 2007 and December 31, 2010 at 787 general care veterinary hospitals in the United States was reviewed. Dogs were selected as cases at the first-time diagnosis of a laboratory-confirmed urolith comprised of at least 70% calcium oxalate (n =452). Two sets of control dogs with no history of urolithiasis diagnosis were randomly selected after the medical records of all remaining dogs were reviewed: urinalysis examination was a requirement in the selection of one set (n =1808) but was not required in the other set (n =1808). Historical information extracted included urolith composition, dog's diet, age, sex, neuter status, breed size category, hospital location, date of diagnosis, and urinalysis results. Multivariable analysis showed that the odds of first-time diagnosis of calcium oxalate urolithiasis were significantly (P <0.05) greater for dogs<7 years, males (OR: 7.77, 95% CI: 4.93–12.26), neutered (OR: 2.58, 1.44–4.63), toy- vs. medium-sized breeds (OR: 3.15, 1.90–5.22), small- vs. medium-sized breeds (OR: 3.05, 1.83–5.08), large- vs. medium-sized breeds (OR: 0.05, 0.01–0.19), and those with a diagnosis of cystitis within the previous year (OR: 6.49, 4.14–10.16). Urinary factors significantly associated with first-time diagnosis of calcium oxalate urolithiasis were acidic vs. basic pH (OR: 1.94, 1.22–3.10), presence of RBCs (OR: 6.20, 3.91–9.83) or WBCs (OR: 1.62, 1.03–2.54), and protein concentration>30mg/dL (OR: 1.55, 1.04–2.30). Patient demographics and urinalysis results are important factors that can support risk assessment and early identification of canine oxalate urolithiasis. Therefore, periodic urolith screening and monitoring of urine parameters should be encouraged for dogs at risk of developing these uroliths. [Copyright &y& Elsevier]

Purpose: Using the Nationwide Emergency Department Sample (NEDS) we examined trends in visits, hospitalization and charges for patients with upper urinary tract stones who presented to the emergency department in the United States. Materials and Methods: All visits with a primary diagnosis of kidney calculus (ICD-9-CM code 592.0), ureter calculus (592.1) or urinary calculus unspecified (592.9) were extracted from NEDS between 2006 and 2009. A weighted sample was used to calculate incidence rates. Temporal trends were quantified by the estimated annual percent change. Patient and hospital characteristics associated with hospitalization were evaluated using logistic regression models adjusted for clustering. Results: Between 2006 and 2009 there were 3,635,054 emergency department visits for upper urinary tract stones. The incidence increased from 289 to 306/100,000 individuals. More men visited than women but women showed significant increases in visits (estimated annual percent change 2.85%, p = 0.018). Total monthly emergency department visits ranged from 5.8% in February to 8.4% in August. Overall 12.0% of patients were hospitalized and the hospitalization rate remained stable (estimated annual percent change –1.02%, p = 0.634). Patients were more likely to be hospitalized if they were female, more ill, seen at an urban teaching or low volume hospital, or had Medicaid or Medicare (each p <0.001). Sepsis was associated with the highest likelihood of hospital admission (OR 69.64, p <0.001). In 2009 charges for emergency department visits increased to $5 billion (estimated annual percent change 10.06%, p = 0.003). Conclusions: Women showed significant annual increases in emergency department visits for upper urinary tract stones. While emergency department charges increased substantially, hospitalization rates remained stable. Greater use of computerized tomography and medical expulsive therapy could be the reasons for this observation, which warrants further study. [Copyright &y& Elsevier]

Background and Purpose: We sought to examine a large nationwide (United States) sample of emergency department (ED) visits to determine data related to utilization and costs of care for urolithiasis in this setting. Methods: Nationwide Emergency Department Sample was analyzed from 2006 to 2009. All patients presenting to the ED with a diagnosis of upper tract urolithiasis were analyzed. Admission rates and total cost were compared by region, hospital type, and payer type. Numbers are weighted estimates that are designed to approximate the total national rate. Results: An average of 1.2 million patients per year were identified with the diagnosis of urolithiasis out of 120 million visits to the ED annually. Overall average rate of admission was 19.21%. Admission rates were highest in the Northeast (24.88%), among teaching hospitals (22.27%), and among Medicare patients (42.04%). The lowest admission rates were noted for self-pay patients (9.76%) and nonmetropolitan hospitals (13.49%). The smallest increases in costs over time were noted in the Northeast. Total costs were least in nonmetropolitan hospitals; however, more patients were transferred to other hospitals. When assessing hospital ownership status, private for-profit hospitals had similar admission rates compared with private not-for-profit hospitals (16.6% vs 15.9%); however, costs were 64% and 48% higher for ED and inpatient admission costs, respectively. Conclusions: Presentation of urolithiasis to the ED is common, and is associated with significant costs to the medical system, which are increasing over time. Costs and rates of admission differ by region, payer type, and hospital type, which may allow us to identify the causes for cost discrepancies and areas to improve efficiency of care delivery. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to assess predictors for new-onset stone formers after Roux-en-Y gastric bypass (RYGBP). Methods: One hundred and fifty-one obese patients underwent RYGBP and were followed for 1 year. The analysis comprised two study time points: preoperative (T0) and 1 year after surgery (T1). They were analyzed for urinary stones, blood tests, and 24-h urinary evaluation. Nonparametric tests, logistic regression, and multivariate analysis were conducted using SPSS 17. Results: Median BMI decreased from 44.1 to 27.0 kg/m ( p < 0.001) in the postoperative period. Urinary oxalate (24 versus 41 mg; p < 0.001) and urinary uric acid (545 versus 645 mg; p < 0.001) increased significantly postoperatively (preoperative versus postoperative, respectively). Urinary volume (1310 versus 930 ml; p < 0.001), pH (6.3 versus 6.2; p = 0.019), citrate (268 versus 170 mg; p < 0.001), calcium (195 versus 105 mg; p < 0.001), and magnesium (130 versus 95 mg; p = 0.004) decreased significantly postoperatively (preoperative versus postoperative, respectively). Stone formers increased from 16 (10.6 %) to 27 (17.8 %) patients in the postoperative analysis ( p = 0.001). Predictors for new stone formers after RYGBP were postoperative urinary oxalate ( p = 0.015) and uric acid ( p = 0.044). Conclusions: RYGBP determined profound changes in urinary composition which predisposed to a lithogenic profile. The prevalence of urinary lithiasis increased almost 70 % in the postoperative period. Postoperative urinary oxalate and uric acid were the only predictors for new stone formers. [ABSTRACT FROM AUTHOR]

Abstract: Background: The incidence of infected urolithiasis is unknown, and evidence describing the optimal management strategy for obstruction is equivocal. Objective: To examine the trends of infected urolithiasis in the United States, the practice patterns of competing treatment modalities, and to compare adverse outcomes. Design, setting, and participants: A weighted estimate of 396385 adult patients hospitalized with infected urolithiasis was extracted from the Nationwide Inpatient Sample, 1999–2009. Outcome measurements and statistical analysis: Time trend analysis examined the incidence of infected urolithiasis and associated sepsis, as well as rates of retrograde ureteral catheterization and percutaneous nephrostomy (PCN) for urgent/emergent decompression. Propensity-score matching compared the rates of adverse outcomes between approaches. Results and limitations: Between 1999 and 2009, the incidence of infected urolithiasis in women increased from 15.5 (95% confidence interval [CI], 15.3–15.6) to 27.6 (27.4–27.8)/100 000); men increased from 7.8 (7.7–7.9) to 12.1 (12.0–12.3)/100000. Rates of associated sepsis increased from 6.9% to 8.5% (p =0.013), and severe sepsis increased from 1.7% to 3.2% (p <0.001); mortality rates remained stable at 0.25–0.20% (p =0.150). Among those undergoing immediate decompression, 113 459 (28.6%), PCN utilization decreased from 16.1% to 11.2% (p =0.001), with significant regional variability. In matched analysis, PCN showed higher rates of sepsis (odds ratio [OR]: 1.63; 95% CI, 1.52–1.74), severe sepsis (OR: 2.28; 95% CI, 2.06–2.52), prolonged length of stay (OR: 3.18; 95% CI, 3.01–3.34), elevated hospital charges (OR: 2.71; 95%CI, 2.57–2.85), and mortality (OR: 3.14; 95%CI, 13–4.63). However, observational data preclude the assessment of timing between outcome and intervention, and disease severity. Conclusions: Between 1999 and 2009, women were twice as likely to have infected urolithiasis. Rates of associated sepsis and severe sepsis increased, but mortality rates remained stable. Analysis of competing treatment strategies for immediate decompression demonstrates decreasing utilization of PCN, which showed higher rates of adverse outcomes. These findings should be viewed as preliminary and hypothesis generating, demonstrating the pressing need for further study. [Copyright &y& Elsevier]

Epidemiological surveys are important tools to identify emerging trends in disease. The Minnesota Urolith Centre has been tracking the occurrence of uroliths for over 30 years. To evaluate global changes in the frequencies of canine uroliths, submissions to the Minnesota Urolith Centre in 1999 and 2000 (n=39,965) were compared with submissions in 2009 and 2010 (n=99,598). The proportion of calcium oxalate uroliths rose on every continent except in Europe. Seventy-five per cent of dogs with calcium oxalate uroliths were between 5 and 11 years old. The proportion of struvite uroliths decreased on every continent except in Australia-Oceania. Seventy-seven per cent of all struvite formers were between two and eight years old. The proportion of purine uroliths has declined slightly. Worldwide, uroliths composed of cystine, calcium phosphate, calcium phosphate carbonate and silica remain uncommon. Epidemiological studies of urolithiasis are essential for constructing effective experimental designs and selecting appropriate cases and controls to conduct clinical trials with meaningful results. [ABSTRACT FROM AUTHOR]

The occurrence of urolithiasis in the United States has increased; however, information on long-term trends, including recurrence rates, is lacking. Here we describe national trends in rates of emergency department visits, use of imaging, and drug treatment, primarily using the National Hospital Ambulatory Medical Care Survey to describe trends and the National Health and Nutrition Examination Survey to determine the frequency of lifetime passage of kidney stones. Emergency department visit rates for urolithiasis increased from 178 to 340 visits per 100,000 individuals from 1992 to 2009. Increases in visit rates were greater in women, Caucasians, and in those aged 25-44 years. The use of computed tomography in urolithiasis patients more than tripled, from 21 to 71%. Medical expulsive therapy was used in 14% of the patients with a urolithiasis diagnosis in 2007-2009. Among National Health and Nutrition Examination Survey participants who reported a history of kidney stones, 22.4% had passed three or more stones. Hence, emergency department urolithiasis visit rates have increased significantly, as has the use of computed tomography in the United States. Further research is necessary to determine whether recurrent stone formers receive unnecessary radiation exposure during diagnostic evaluation in the emergency department and allow development of corresponding evidence-based guidelines. [ABSTRACT FROM AUTHOR]

Introduction: The prevalence of upper urinary tract stone disease (USD) in the United States is rising among both adults and children. Studies on the contemporary economic burden of USD management in the pediatric population are lacking., Objective: To comprehensively analyze the economic impact of USD in a contemporary United States pediatric cohort, and to evaluate drivers of cost., Study Design: A retrospective cohort study of pediatric patients (aged 0-17), diagnosed with USD between 2011 and 2018 were identified from PearlDiver-Mariner, an all-payer claims database containing diagnostic, treatment and prescription data provided in all treatment settings. Relevant International Classification of Disease (ICD-9 and ICD-10) and Current Procedural Terminology (CPT) codes were used for identification, and only patients with claims recorded for at least one year before and after entry of a diagnosis code for USD were selected (N = 10,045). Patients were stratified into those undergoing operative vs. non-operative management and for each patient, total 1-year healthcare costs following USD diagnosis, including same day and non-same day encounters, were analyzed. Factors associated with increased spending, as well as economic trends were analyzed., Results: Overall, 8498 (85%) patients were managed non-operatively, while 1547 (15%) underwent a total of 1880 procedural interventions. Total overall cost was $117.1 million, while median annual expenditure was $15.8 million. Proportion of spending for outpatient, inpatient and prescription services was 52%, 32% and 16%, respectively (Table). Outpatient management accounted for 67% of overall spending. The proportion of patients managed non-operatively increased significantly over time, in parallel with spending for non-operative care. Comorbidity burden, treatment year and geographic region were among predictors of costs., Discussion: Our study is the first to report actual insurance reimbursements for pediatric USD management using actual reimbursement data, examined across all treatment settings. We found that majority of the costs were for outpatient services and for non-operative management, with a rising tendency toward non-operative management over time. Regional variation in expenditures was evident. Specific reasons underlying these observed patterns could not directly be discerned from our dataset, but merit further investigation., Conclusion: Non-operative and outpatient management for pediatric USD are increasingly common, resulting in parallel shifts in spending. Notably, 52% of overall spending was for outpatient care. These insights into the contemporary economic burden of pediatric USD could provide value in shaping future healthcare policy., (Copyright © 2022 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Purpose: The incidence of urolithiasis in children is increasing. However, stone composition studies in this population are limited. We sought to determine the effects of age, gender and geographical location on urinary stone composition in the United States pediatric population. Materials and Methods: We obtained composition analyses for all urinary stones submitted to a reference laboratory between 2000 and 2009. Stones were excluded if the patient was younger than 1 year or older than 18 years. Stone composition was determined by Fourier transform infrared spectroscopy. Logistic regression analysis was performed to determine associations between stone composition frequency and age, gender and geographical region. Results: A total of 5,245 stones were included in our analysis. Calcium was found in 89.2% of stones. The percentage of stones containing calcium oxalate increased, while magnesium ammonium phosphate and ammonium acid urate containing stones decreased with age. Calcium oxalate and magnesium ammonium phosphate containing stones were more common in females, while uric acid stones were more common in males. Additionally, significant differences in stone composition frequency were noted between males and females in specific age groups and between age groups within the same gender. Geographical distribution was not significantly associated with stone composition. Conclusions: This series is the largest analysis to date of urinary stone composition in the pediatric population in the United States. Age and gender were significantly associated with stone composition, while geographical region was not significantly associated with stone composition. [ABSTRACT FROM AUTHOR]

Objective: To review the Nationwide Inpatient Sample database to examine the relationships between obesity, gender, and nephrolithiasis. Recent reports indicate that the prevalence of nephrolithiasis has been increasing, especially among women. Methods: The Nationwide Inpatient Sample contains data on approximately 20% of hospital stays in the United States. Included in this analysis were discharges with primary diagnosis ICD-9 codes 592.0 (renal calculus) or 592.1 (ureteral calculus), from 1998 through 2003. All raw data were weighted to produce national estimates. Descriptive and inferential statistics were performed to determine changes in nephrolithiasis prevalence and associations of obesity and other comorbidities with nephrolithiasis. Results: We reviewed 181,092,957 hospital stays (weighted data). The prevalence of nephrolithiasis was relatively stable: 0.52% (149,302) in 1998 and 0.47% (147,541) in 2003. The prevalence of obesity increased from 3.06% (878,155) to 4.99% (1,575,247). The male:female ratio of patients with stones decreased from 1.6:1 to 1.2:1. Multivariate analysis revealed a statistically significant relationship (OR = 1.22, 95% CI 1.20–1.23, P <.001) between obesity and urinary stones. Obese females were more likely to develop stones than nonobese females (OR = 1.35, 95% CI 1.33–1.37, P <.001). The association between obesity and stones was weaker in males (OR = 1.04, 95% CI 1.02–1.06, P <.001). Conclusion: In this sample of inpatients, obesity was associated with a significantly increased prevalence of urinary stones. This relationship was stronger in females than in males. Further studies are needed to determine whether weight reduction in obese patients affects urinary stone disease. [ABSTRACT FROM AUTHOR]

Purpose: Shock wave lithotripsy and ureteroscopy are highly effective treatments for urinary lithiasis. While stone size and location are primary determinants of therapy, little is known about other factors associated with treatment. We identified patient, provider and practice setting characteristics associated with the selection of ureteroscopy or shock wave lithotripsy. Materials and Methods: We used the Medicare 5% sample to identify beneficiaries with an incident stone encounter from 1997 to 2007. Within this group we identified beneficiaries undergoing shock wave lithotripsy or ureteroscopy for the management of urinary calculi. Multivariable regression models identified factors associated with the use of ureteroscopy. Results: The cohort comprised 9,358 beneficiaries who underwent an initial procedure. Shock wave lithotripsy was used in 5,208 (56%) beneficiaries while ureteroscopy was used in 4,150 (44%). Female patients were less likely than males to undergo ureteroscopy (OR 0.844, p = 0.006). Providers who more recently completed residency training used ureteroscopy more often (p = 0.023). Provider and facility volume were associated with initial procedure selection. The odds of a second procedure following initial shock wave lithotripsy were 1.54 times those of ureteroscopy (p <0.001). Conclusions: Nonclinical factors are associated with the use of ureteroscopy or shock wave lithotripsy for initial stone management, which may reflect provider and/or patient preferences or experience. Further investigation is required to understand the impact of these outcomes on quality and cost of care. [ABSTRACT FROM AUTHOR]

Purpose: We categorized trends in failure of the stone baskets as reported in the United States Food and Drug Administration Manufacturer and User Facility Device Experience database. Materials and Methods: We queried the online database using the code for stone baskets (FFL) from January 1996 to December 2009. Variables extracted were the type of basket, malfunction and treatment, and patient outcome. Results: We identified 556 adverse events related to stone baskets. The device configuration was tipped in 48% of cases, tipless in 36%, forceps in 8% and the Stone Cone™ in 8%. Malfunction type included detachment of a portion of the basket in 49% of cases, breakage without detachment in 39% and inability to withdraw the basket in 12%. Compared to the early period studied (1996 to 2004) there was a 3-fold increase in adverse events from 2005 to 2007 and a 6-fold increase from 2008 to 2009. Of adverse events 79% and 11% were managed by endoscopy and open surgery, respectively. Of the patients 42 experienced serious complications requiring major surgery, including ureteral reconstruction in 7, reimplantation in 4 and nephrectomy in 7. Conclusions: With the increased use of stone baskets in the upper collecting system the number of adverse events has increased. Urologists should remain vigilant to prevent, recognize and manage these events. [ABSTRACT FROM AUTHOR]

This project sought to test the ability of commercial stone analysis laboratories to correctly analyze urinary stones. Human stone specimens were cleaved into pieces, and the pieces of each specimen were verified as being similar using micro-computed tomography (micro CT), a non-destructive method. Thus, similar specimens from 25 stones were sent to five laboratories, and a sixth piece was kept for analysis in our laboratory using Fourier-transform infrared spectroscopy (FT-IR). The results showed that laboratories were very good at analyzing pure specimens, but with mixed specimens the accuracy and consistency varied. In six stones containing apatite, a mineral easily identified using micro CT, apatite was missed 20% of the time. Struvite content in the specimens was inconsistently reported, with laboratories differing in their reports of the presence of struvite in six of the 25 stones (24%). A mixed stone containing atazanavir was not reported by any of the laboratories as containing that drug. Nomenclature differed among the laboratories, especially with regard to apatite, which was variously reported as hydroxyapatite, carbonate apatite, or as apatite with calcium carbonate. One laboratory reported protein in every stone, while for all others protein was reported in only one stone. We conclude that physicians need to be aware that reports on mixed stones, which represent >90% of all calculi, can be erroneous. It is likely that supplying a greater amount of stone material will assist a laboratory in making a correct analysis of mixed stones. Also, standardization of nomenclature could assist in analysis reproducibility, but this remains to be tested. [ABSTRACT FROM AUTHOR]

Purpose: Anecdotal and lay press reports suggest that the incidence of pediatric urolithiasis is increasing but reliable data are lacking. The objective of this study was to examine trends in the epidemiology of urolithiasis at pediatric hospitals nationwide. Materials and Methods: The Pediatric Health Information System database is a national database covering 42 freestanding United States pediatric hospitals that captures inpatient admissions, and emergency department and outpatient surgery visits. We searched the Pediatric Health Information System database to identify children (18 years old or younger) treated for urolithiasis between 1999 and 2008. Patients with urolithiasis were measured as a proportion of the total number of patients seen per hospital annually. Trends were verified by comparing results to 2 other common pediatric diagnoses—appendicitis and viral bronchiolitis. Results: We identified 7,921 children diagnosed with urolithiasis during the study period. The total number of children with urolithiasis seen in Pediatric Health Information System hospitals increased from 125 in 1999 to 1,389 in 2008. Mean number of stone cases per hospital per year increased from 13.9 to 32.6. Compared to total hospital patients, the proportion of patients with pediatric urolithiasis increased from 18.4 per 100,000 in 1999 to 57.0 per 100,000 in 2008, an adjusted annual increase of 10.6% (p <0.0001). Urolithiasis also increased compared to appendicitis (p <0.0001) and bronchiolitis (p <0.0001). Conclusions: Even after correcting for increases in total patient volume at Pediatric Health Information System hospitals, there has been a significant increase in the number of children diagnosed with and treated for urolithiasis at these hospitals in the last decade. [ABSTRACT FROM AUTHOR]

Purpose: Studies have shown that bladder management with an indwelling catheter for patients with spinal cord injury is associated with more urological complications such as stones, urinary infection, urethral strictures and bladder cancer. However, little is known about actual bladder management for these patients in clinical practice. Materials and Methods: Using the National Spinal Cord Injury Database the bladder management method was determined at discharge from rehabilitation and at each 5-year followup period for 30 years. Results: At discharge from rehabilitation (24,762 patients) the selection of bladder management with a condom catheter decreased steadily from a peak of 34.6% in 1972 to a low of 1.50% in 2001. The use of clean intermittent catheterization increased from 12.6% in 1972 to a peak of 56.2% in 1991. Indwelling catheter use initially decreased from 33.1% in 1972 to 16.5% in 1991 but increased to 23.1% in 2001. Of 12,984 individuals with followup data those originally using an indwelling catheter for bladder management were unlikely to switch to another method, with 71.1% continuing to use an indwelling catheter at 30 years. Individuals using clean intermittent catheterization and condom catheterization at discharge home did not continue to use these methods with only 20% and 34.6% remaining on the same management, respectively. Conclusions: With time bladder management with clean intermittent catheterization has increased in popularity. However, only 20% of patients initially on clean intermittent catheterization remained on this form of bladder management. More research on the safety of each of these methods needs to be performed to provide better guidance to aid with this decision. [Copyright &y& Elsevier]

Purpose: Although more common in adults, urolithiasis recently has been occurring with increasing frequency in children. Single institution reviews from 1950 to 1990 revealed that urolithiasis accounts for 1 in 7,600 to 1 in 1,000 pediatric hospitalizations. Stone prevalence and risk factors for hospitalization are less defined in children in North America compared to adults. To identify pediatric hospital admissions due to a diagnosis of urinary stones, we examined Pediatric Health Information System data from 41 freestanding pediatric hospitals. Materials and Methods: We retrospectively studied patients younger than 18 years hospitalized between 2002 and 2007. The Pediatric Health Information System database, a validated collection of pediatric hospital data, was searched for inpatients with a primary ICD-9 diagnosis of urolithiasis. Results: Among more than 2.7 million pediatric inpatients from 2002 to 2007, 3,989 hospitalizations were for 3,815 patients with urolithiasis. In contrast to adults, girls had a 1.5-fold greater likelihood of being hospitalized for stones. More than half of the children (53.1%) were younger than 13 years (mean 12.3, SD 4.23). Most patients (88%) were white. Stone hospitalizations were more common in the North Central region compared to the South. Hospitalizations for stones increased slightly in August and September. Nephrectomy was performed in nearly 1% of stone hospitalizations (29 of 3,170). Conclusions: Children with stones now account for 1 in 685 pediatric hospitalizations in the United States. Surprisingly more than half of the patients are younger than 13 years at hospitalization. Similar to findings in adults, white race and occurrence in late summer months increase the risk of stone hospitalization. However, male gender and geographic location in the Southeast are not risk factors, demonstrating the unique aspects of pediatric stone hospitalization. [Copyright &y& Elsevier]

Objectives: Between 2000 and 2006, 11 randomized controlled trials were published, demonstrating the efficacy of medical expulsive therapy (MET) for promoting upper tract stone passage. Although its use is gaining traction among urologists, they evaluate a minority of patients who present to the emergency department (ED) for acute renal colic before discharge. As such, measuring the uptake of MET into the broader medical community is important. Methods: Data were analyzed (2000-2006) from the National Hospital Ambulatory Medical Care Survey. Sampled ED visits for stones were identified. The use of MET was ascertained by the prescription of a calcium channel or α blocker at the ED visit. National estimates of the prevalence of MET use were computed. Logistic regression was used to examine linear and nonlinear time trends in MET prescription. Results: The use of MET increased throughout the study period. In fact, the odds of being treated with this approach more than doubled with each successive year (OR, 2.15; 95% CI, 1.31-3.5; P < .001 for the linear trend). However, the overall prevalence of use was exceedingly low at 1.1% (95% CI, 0.6%-1.9%). Given the number needed to treat of 4, this implies a missed opportunity to spare approximately 260 000 individuals annually from stone surgery and its risks. Conclusions: Despite the growing body of evidence to support its safety and efficacy, our analysis reveals the sluggish dissemination of MET into the broader medical community. The observed underuse represents a block in the translation of clinical science into practice and raises a quality of care concern. [Copyright &y& Elsevier]

AbstractObjective:To evaluate current practice patterns in U.S. emergency departments (EDs) for the diagnosis, treatment, and counseling of patients with ureteral calculi.Methods:Hospital-based ED physicians were invited by e-mail to participate in a Survey-Monkey survey. E-mails were delivered in March 2008 by Direct Medical Data using a listserv provided by the American Medical Association. Of the e-mails sent, 173 e-mails were opened, and 135 physicians responded. Physicians were compensated with a $10 Amazon.com gift card.Results:Ninety percent of ED physicians use noncontrast CT as their initial imaging modality, and 63% use alpha-blockers for medical expulsive therapy. Only 13% of evaluated EDs have guidelines for the management of renal colic, and only 58% of these guidelines that recommend the use of an alpha-blocker. Alpha-blocker use was more common with physicians who have been practicing fewer than 5 years (81%) compared with those with more than 10 years of experience (56%). The majority of physicians used ketorolac and morphine to achieve effective analgesia. Although the average responses concerning the chance of spontaneous stone passage for stones ≤4 mm (87%) and >4 mm (44%) were close to evidence-based values, great variation in the answers was noted (standard deviations: 12% and 22%, respectively). Indeed, 38% of respondents stated that stones ≤4 mm had a >95% chance of passage. Twenty-eight percent of ED physicians would arrange follow-up with a primary care physician, while the remainder would arrange follow-up with a urologist.Conclusions:This study establishes a need for educational opportunities for ED physicians in the management of renal colic. The development of collaborative practice guidelines between urology and emergency medicine associations may be warranted. [ABSTRACT FROM AUTHOR]

OBJECTIVE To evaluate the efficacy of stone volume measured using a three-dimensional (3D) reconstruction of preoperative non-contrast computed tomography (NCCT) as an independent predictor of success after extracorporeal shock wave lithotripsy (ESWL) of upper urinary tract calculi. PATIENTS AND METHODS We evaluated preoperative NCCT in 94 patients who had ESWL for solitary upper urinary tract calculi of 4–20 mm in diameter. Axial images were used to measure the skin-to-stone distance (SSD), Hounsfield Unit (HU) density and axial stone diameter. Stone volume was calculated on a volume-rendered 3D image for each stone. Maximum stone length was determined by comparative measurements of each stone in coronal, sagittal and axial planes, and was also measured on a plain abdominal film before ESWL. For ESWL we used the DoliS lithotripter (Dornier Medical Systems, Marrietta, GA, USA). A plain film at 6 weeks was used to categorize patients as stone-free (SF) or with residual stone. RESULTS In all, 58 (62%) patients were SF and 36 (38%) had RS; the mean stone volume was significantly different between these groups (274 vs 464 µL, P = 0.002). Logistic regression analysis showed that stone volume was the strongest predictor of SF status ( P < 0.001), compared to peak HU ( P = 0.015), mean HU ( P = 0.04) and axial stone diameter ( P = 0.006). The body mass index, SSD and maximum stone length on NCCT or a plain film did not predict success. A stone volume of <500 µL best predicted treatment success ( P < 0.001) with 72% of patients with a stone volume of <500 µL having a successful outcome, vs only 27% with a stone volume of >500 µL. CONCLUSION Our study suggests that stone volume is an optimal predictor of SF status after ESWL of solitary upper urinary tract calculi. [ABSTRACT FROM AUTHOR]

An unanticipated result of global warming is the likely northward expansion of the present-day southeastern U.S. kidney stone "belt." The fraction of the U.S. population living in high-risk zones for nephrolithiasis will grow from 40% in 2000 to 56% by 2050, and to 70% by 2095. Predictions based on a climate model of intermediate severity warming (SRESa1b) indicate a climate-related increase of 1.6-2.2 million lifetime cases of nephrolithiasis by 2050, representing up to a 30% increase in some climate divisions. Nationwide, the cost increase associated with this rise in nephrolithiasis would be $0.9-1.3 billion annually (year-2000 dollars), representing a 25% increase over current expenditures. The impact of these changes will be geographically concentrated, depending on the precise relationship between temperature and stone risk. Stone risk may abruptly increase at a threshold temperature (nonlinear model) or increase steadily with temperature change (linear model) or some combination thereof. The linear model predicts increases by 2050 that are concentrated in California, Texas, Florida, and the Eastern Seaboard; the nonlinear model predicts concentration in a geographic band stretching from Kansas to Kentucky and Northern California, immediately south of the threshold isotherm. [ABSTRACT FROM AUTHOR]

This article focuses on the etiology of urolithiasis and nephrolithiasis. Urolithiasis, urinary tract calculi or stones, and nephrolithiasis, kidney calculi or stones, are two commonly occurring diseases in the U.S. According to several studies, about 10% of the U.S. population develops a kidney stone in their lifetime. Several researchers have revealed a direct connection between the incidence of nephrolithiasis and the dietary preference of foods high in animal protein in the U.S. Nephrolithiasis is most prevalent between the ages of 20 to 40. Some of the factors identified as the contributing factors to stone development are: congenital kidney defects, hypertension, colitis, inflammation of colon, and chronic diarrheal states, Crohn's disease results in dehydration and low citrate, and obesity and high body mass index. Both chemotherapy and surgical therapies are recommended by physicians, depending on the severity and size of the stones.

: ObjectivesTo present our initial results using the Dornier Doli S lithotriptor with the 220 electromagnetic shock wave emitter to treat urinary calculi. At present, there is no published report of the efficacy of this instrument in service in the United States.: MethodsWe retrospectively reviewed the outcome of shock wave lithotripsy in 270 consecutive patients with solitary renal and/or ureteral stones treated from September 1998 to October 2001 with the Dornier Doli S lithotriptor. Data were collected with respect to stone size, location, and fragmentation.: ResultsOf the 270 patients treated, 204 had renal stones and 66 had ureteral stones. All patients had solitary stones. The renal stones averaged 9.7 mm in size (range 4 to 26). The ureteral stones averaged 7.8 mm (range 4 to 17). Of the renal stones, 51% were located in the renal pelvis, with 18%, 5%, and 25% located in the upper, middle, and lower poles, respectively. Of the ureteral stones, 68% were located in the proximal ureter, with 14% and 18% in the mid and distal ureter, respectively. In the renal group, 176 (86%) of 204 patients achieved clinical success. Of these patients, 148 were stone free (73%) and 28 had residual fragments less than 4 mm in size (14%). In the ureteral group, 52 (79%) of 66 patients achieved clinical success. Of these patients, 50 were stone free (76%) and 2 (3%) patients had fragments less than 4 mm in size. Thirteen (6%) of 204 patients in the renal group required retreatment. Four (6%) of 62 patients in the ureteral group required retreatment. Of the patients in whom treatment failed and who had stone analysis, 16 (76%) of 21 had stones composed of predominantly calcium oxalate monohydrate. Four patients developed steinstrasse. Two were treated with retrograde stent placement, and the other two with placement of percutaneous nephrostomy. One patient developed a known perinephric hematoma but did not require a blood transfusion.: ConclusionsShock wave lithotripsy using the Doli S in appropriately selected patients is an effective instrument for treating urinary calculi throughout the urinary tract. [Copyright &y& Elsevier]

About one-half million adults in the United States experience a renal stone each year, about two hundred thousand of whom are hospitalized; the lifetime incidence of renal stones in men is about ten percent. Risk factors for stone formation include a positive family history, nutritional factors (excessive intake of animal protein, fat, sugar, oxalates, colas, alcohol, caffeine, salt, and vitamin D), nutritional deficiencies (water, magnesium, calcium, potassium, and vitamin B6), lifestyle factors (physical inactivity and problematic pharmaceuticals), and associated disease states (osteoporosis, parathyroid problems, osteoporosis, gout and recurrent urinary tract infections). The chemical makeup of the stone is important since prevention of recurrences varies somewhat depending on the type of stone involved. The outline of preventive steps holds the potential for preventing recurrence in the vast majority of cases. [ABSTRACT FROM AUTHOR]

Objective: To determine the risk of postpartum urinary stone disease in women with a history of stone disease during pregnancy. Methods: Using the Optum ® de-identified Clinformatics ® Datamart we identified pregnant women with urinary stone disease in the United States between January 2003 to December 2017 by standardized International Classification of Diseases Ninth and Tenth Editions (ICD-9 and ICD-10), and Current Procedural Terminology code criteria. We limited the cohort to include women without evidence of urinary stone disease before pregnancy. We abstracted patient demographic characteristics, clinical risk factors for stone disease, and data for urinary stone disease encounters and related procedures after pregnancy. Encounters occurring within 1 year of pregnancy were excluded. Cox proportional hazard models were used to analyze for significance. Results: We identified a total of 1,395,783 pregnant women with a median postpartum follow-up of 4.0 years, including 5971 (0.4%) women with a urinary stone during pregnancy. Of these, 736 ( 12.3% ) had an additional urinary stone diagnosis claim after pregnancy, compared with 13,275 (0.95%) women without a history of stone disease during pregnancy ( p  < 0.0001). In multivariable proportional hazards models urinary stone disease during pregnancy (hazards ratio 12.8, 95% confidence interval [11.8-13.8]) was independently associated with a higher hazard of urinary stone disease after pregnancy. Conclusion: Women with urinary stone disease during pregnancy were more likely to present with recurrent urinary stone disease after pregnancy. Given the one in eight chance of needing further care, women with history of stone disease during pregnancy may benefit from risk counseling, surveillance, or secondary prevention efforts in the postpartum period.

Examines the incidence of age related fractures among the residents diagnosed with urolithiasis in Minnesota. Impact of risk factors for fracture on the effects of kidney stones; Causes of bone loss and fractures; Increase in serum calcium levels and reduction of bone demineralization.