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Objective: The American Urological Association guidelines recommend 24-hour urine testing in patients with urinary stone disease to decrease the risk of stone recurrence; however, national practice patterns for 24-hour urine testing are not well characterized. Our objective is to determine the prevalence of 24-hour urine testing in patients with urinary stone disease in the Veterans Health Administration and examine patient-specific and facility-level factors associated with 24-hour urine testing. Identifying variations in clinical practice can inform future quality improvement efforts in the management of urinary stone disease in integrated healthcare systems., Materials and Methods: We accessed national Veterans Health Administration data through the Corporate Data Warehouse (CDW), hosted by the Veterans Affairs Informatics and Computing Infrastructure (VINCI), to identify patients with urinary stone disease. We defined stone formers as Veterans with one inpatient ICD-9 code for kidney or ureteral stones, two or more outpatient ICD-9 codes for kidney or ureteral stones, or one or more CPT codes for kidney or ureteral stone procedures from 2007 through 2013. We defined a 24-hour urine test as a 24-hour collection for calcium, oxalate, citrate or sulfate. We used multivariable regression to assess demographic, geographic, and selected clinical factors associated with 24-hour urine testing., Results: We identified 130,489 Veterans with urinary stone disease; 19,288 (14.8%) underwent 24-hour urine testing. Patients who completed 24-hour urine testing were younger, had fewer comorbidities, and were more likely to be White. Utilization of 24-hour urine testing varied widely by geography and facility, the latter ranging from 1 to 40%., Conclusions: Fewer than one in six patients with urinary stone disease complete 24-hour urine testing in the Veterans Health Administration. In addition, utilization of 24-hour urine testing varies widely by facility identifying a target area for improvement in the care of patients with urinary stone disease. Future efforts to increase utilization of 24-hour urine testing and improve clinician awareness of targeted approaches to stone prevention may be warranted to reduce the morbidity and cost of urinary stone disease., Competing Interests: The authors have declared that no competing interests exist.

Aim: to study the calcium level in the urine, serum and hairs and to assess the diagnostic value of the calcium level in various biosubstrates in patients with calcium and non-calcium stones., Materials and Methods: a total of 99 patients with urinary stone disease were included in the study. A diagnostic value of calcium level in biosubstrates according to the chemical analysis of stone composition performed using qualitative chemical reactions and microcrystalloscopy was evaluated., Results: Urinary level of calcium and oxalate is proved to have high diagnostic value in patients with calcium nephrolithiasis (specificity 93.9% and 96.9%, and positive predictive value 88.2% and 97.2%, respectively). The specificity and positive predictive value of the calcium level in the hairs was 81.2% and 87.2%, respectively., Conclusion: A comprehensive study of the elemental spectrum in urine, hair, and serum increases the diagnostic value of the evaluation of calcium, determined by the type of studied biosubstrate and stone type in patients with nephrolithiasis.

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues., (© 2019 The Japanese Urological Association.)

Urethral diverticulum is a condition where the urethra or the periurethral glands push into the connective tissue layers that surround it. Patients of urethral diverticulum present with nonspecific symptoms such as incontinence, urinary frequency and urgency, and pain during sexual intercourse and urination. The incidence of this condition is low. We report a case of giant anterior urethra stones combined with a diverticulum with no lower urinary tract symptoms. We believe that this case is extremely rare, and the process of diagnosis and treatment is of great significance in clinical practice.

Ultra-high-speed video microscopy and numerical modeling were used to assess the dynamics of microbubbles at the surface of urinary stones. Lipid-shell microbubbles designed to accumulate on stone surfaces were driven by bursts of ultrasound in the sub-MHz range with pressure amplitudes on the order of 1 MPa. Microbubbles were observed to undergo repeated cycles of expansion and violent collapse. At maximum expansion, the microbubbles' cross-section resembled an ellipse truncated by the stone. Approximating the bubble shape as an oblate spheroid, this study modeled the collapse by solving the multicomponent Euler equations with a two-dimensional-axisymmetric code with adaptive mesh refinement for fine resolution of the gas-liquid interface. Modeled bubble collapse and high-speed video microscopy showed a distinctive circumferential pinching during the collapse. In the numerical model, this pinching was associated with bidirectional microjetting normal to the rigid surface and toroidal collapse of the bubble. Modeled pressure spikes had amplitudes two-to-three orders of magnitude greater than that of the driving wave. Micro-computed tomography was used to study surface erosion and formation of microcracks from the action of microbubbles. This study suggests that engineered microbubbles enable stone-treatment modalities with driving pressures significantly lower than those required without the microbubbles.

Competing Interests: Competing interests: None declared.

Disposable stone retrieval devices are an inherent element of modern-day stone management. Efforts are being made in several different areas to improve the efficiency of stone removal. Ureteral access sheaths with pressure control features as well as suction capabilities are being explored as one such mechanism. Additional efforts are being made to improve stone basket design, grasping capabilities, and deployment mechanisms. Finally, bioadhesives are being developed to potentially improve the capability to extract otherwise difficult small stone fragments and debris from the kidney., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Renal hypouricemia (RHUC) is a disease caused by dysfunction of renal urate reabsorption transporters; however, diagnostic guidance and guidelines for RHUC have been lacking, partly due to the low evidence level of studies on RHUC. This review describes a world-first clinical practice guideline (CPG) and its first version in English for this condition. It was developed following the "MINDS Manual for Guideline Development" methodology, which prioritizes evidence-based medicine. It was published in Japanese in 2017 and later translated into English. The primary goal of this CPG is to clarify the criteria for diagnosing RHUC; another aim is to work towards a consensus on clinical decision-making. One of the CPG's unique points is that it contains textbook descriptions at the expert consensus level, in addition to two clinical questions and recommendations derived from a systematic review of the literature. The guidance shown in this CPG makes it easy to diagnose RHUC from simple blood and urine tests. This CPG contains almost all of the clinical foci of RHUC: epidemiology, pathophysiology, diagnostic guidance, clinical examinations, differential diagnosis, and complications, including exercise-induced acute kidney injury and urolithiasis. A CPG summary as well as a clinical algorithm to assist healthcare providers with a quick reference and notes from an athlete for both physicians and patients are included. We hope that this CPG will help healthcare providers and patients to make clinical decisions, and that it will promote further research on RHUC.

Infection stones are complex aggregates of crystals amalgamated in an organic matrix that are strictly associated with urinary tract infections. The management of patients who form infection stones is challenging owing to the complexity of the calculi and high recurrence rates. The formation of infection stones is a multifactorial process that can be driven by urine chemistry, the urine microenvironment, the presence of modulator substances in urine, associations with bacteria, and the development of biofilms. Despite decades of investigation, the mechanisms of infection stone formation are still poorly understood. A mechanistic understanding of the formation and growth of infection stones - including the role of organics in the stone matrix, microorganisms, and biofilms in stone formation and their effect on stone characteristics - and the medical implications of these insights might be crucial for the development of improved treatments. Tools and approaches used in various disciplines (for example, engineering, chemistry, mineralogy, and microbiology) can be applied to further understand the microorganism-mineral interactions that lead to infection stone formation. Thus, the use of integrated multidisciplinary approaches is imperative to improve the diagnosis, prevention, and treatment of infection stones.

Purpose of Review: To summarize recommendations of the guidelines of the American Urological Association and European Association of Urology, and our opinion on which urinary tract stone disease patients should be metabolically evaluated at which moment and how often., Recent Findings: A standard metabolic evaluation should be performed in all stone formers to prevent recurrent disease. This includes a medical and lifestyle history, physical examination, basic urine and blood analysis, radiological examination and stone analysis. The latter should already be performed during surgery, especially when only a couple of fragments are sent for analysis. Supplementary, performing a 24-h urine analysis should be supported in all patients to understand the lithogenic process that will guide the according follow-up. When risk factors are found, an extended individualized metabolic evaluation should be performed to exclude underlying metabolic diseases and to start stone-specific recurrence prevention., Summary: Urologists should be trained in perioperative stone characterization, because it contains information of urinary environment at the times of stone formation and growth. The extensiveness and frequency of metabolic work-up and follow-up of stone formers should be tailored to the type of stone, severity of the disease, patient's comorbidities and medications.

Background: The diagnosis and follow-up of stone forming patients is usually performed by analysis of 24-h urine samples. However, crystallization risk varies throughout the day, being higher at night. The main objective of this study is to evaluate the urinary crystallization risk in adults and children by calculating risk indexes based on different collection periods., Methods: The study included 149 adults (82 healthy and 67 stone-formers) and 108 children (87 healthy and 21 stone-formers). 24-h urine was collected, divided into 12-h daytime sample (8 am to 8 pm), and 12-h overnight sample (8 pm to 8 am next morning). Solute concentrations, the calcium to citrate ratio (Ca/Cit), and the ion activity product of calcium oxalate (AP[CaOx]) and calcium phosphate (AP[CaP]) were calculated in each 12-h sample and in overall 24-h urine. Assessments were also related to stone type., Results: Ca/Cit and AP(CaOx) were significantly higher in stone forming patients than in healthy subjects. The 12-h overnight samples had the highest values for both risk indexes, confirming a greater risk for crystallization at night. The AP(CaP) index was significantly higher in patients with pure hydroxyapatite stones than healthy controls, but was not significantly different between stone-formers overall and healthy controls., Conclusions: The calculation of risk indexes is a simple method that clinicians can use to estimate crystallization risk. For this purpose, the use of 12-h overnight urine may be a reliable alternative to 24-h collections.

Introduction: A "Negative" ureteroscopy (URS) is defined as a URS in which no stone is found during the procedure. It may occur when the stone has already been passed spontaneously or when it is located outside the collecting system. The aim of the study was to outline risk factors for Negative-URS., Materials and Methods: We retrospectively analyzed the possible risk factors for Negative-URS from a database of 341 URS cases. In every case where presumptive ureteral stone was not found, a formal nephroscopy as well as a whole collecting system revision was completed. The Negative-URS group was compared with the non-Negative-URS group, in terms of patient and stone characteristics., Results: The database of 341 URS cases included 448 different stone instances, of which 17 (3.8%) were negative and 431 (96.2%) were therapeutic. There was no statistical significant difference between the two groups concerning age, body mass index, stone location in the ureter, stone laterality, and whether the patient was prestented. The stepwise multiple logistic regression revealed three important risk factors, namely CT stone surface area (p < 0.0001), radiopacity of the stone at kidney, ureter, and bladder radiograph (KUB; p = 0.0004), and gender (p = 0.0011) with an area under the curve of 0.91. Women were found to have more possibilities to have a negative procedure by four- to sevenfold than men depending on the model. A nonradio-opaque stone at KUB is more likely to be correlated with a Negative-URS by 9.5- to 11-fold more than a radiopaque stone at KUB. For each increase of 1 U in CT stone surface area, there is an increase of 10%-12% to be non-negative., Conclusions: Female gender, a nonradio-opaque stone at KUB, and a smaller stone surface were statistically significantly different in the Negative-URS population.

Uric acid stones account for 10%-15% of all urinary stones. Changes in dietary habits, environment or both can result in the increase of uric acid stones. The formation of uric acid stones is related to hyperuricosuria, low urinary volume and persistently low urinary pH. Diabetes and obesity also significantly increase the risk of stone formation. Dual-energy CT provides a convenient and reliable method for diagnosis. Stone composition analysis and 24-hour urine metabolic evaluations should be considered for further evaluation. Most small uric acid stones (diameter <2 cm) can be treated by pharmacotherapy or extracorporeal shock wave lithotripsy. However, ureteroscopy and other minimally invasive procedures should be reserved for larger stones (diameter ≥2 cm), or patients with concomitant urinary tract obstruction and/or infections. Additionally, adjustment of potential pathophysiologic defects by pharmacotherapy and dietary modification is strongly recommended for the prevention of uric stone recurrence., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Purpose: We determined the association between urology consultation and emergency department revisits for children with urinary stones., Materials and Methods: This retrospective cohort study included patients 18 years old or younger who presented to an emergency department in South Carolina with a urinary stone from 1997 to 2015. The primary exposure was urology consultation during the index emergency department visit. The primary outcome was a stone related emergency department revisit occurring within 180 days of discharge from an index emergency department visit. Secondary outcomes included computerized tomography use, inpatient admission and emergent surgery., Results: Of 5,642 index emergency department visits for acute urinary stones 11% resulted in at least 1 stone related emergency department revisit within 180 days. Of revisits 59% occurred within 30 days of discharge and 39% were due to pain. The odds of emergency department revisit were highest within the first 48 hours of discharge home (OR 22.6, 95% CI 18.0 to 28.5) and rapidly decreased thereafter. Urology consultation was associated with a 37% lower adjusted odds of emergency department revisit (OR 0.63, 95% CI 0.44 to 0.90) and 68% lower odds of computerized tomography use across all emergency department visits (OR 0.32, 95% CI 0.15 to 0.69). Among patients who revisited the emergency department the frequency of pain complaints was 27% in those with a urological consultation at the index visit and 39% in those without., Conclusions: Urology consultation was associated with decreased emergency department revisits and computerized tomography use in pediatric patients with urinary stones. Future studies should identify patients who benefit most from urology consultation and ascertain processes of care that decrease emergency department revisits among high risk patients., (Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Introduction: To compare the accuracy and reliability of stone volume estimated by ellipsoid formula (EFv) and CT-based algorithm (CTv) to true volume (TV) by water displacement in an in vitro model., Materials and Methods: Ninety stone phantoms were created using clay (0.5-40 cm 3 , 814 HU ±91) and scanned with CT. For each stone, TV was measured by water displacement, CTv was calculated by the region-growing algorithm in the CT-based software AGFA IMPAX Volume Viewer, and EFv was calculated by the standard formula π × L × W × H × 0.167. All measurements were repeated thrice, and concordance correlation coefficient (CCC) was calculated for the whole group, as well as subgroups based on volume (<1.5 cm 3 , 1.5-6 cm 3 , and >6 cm 3 )., Results: Mean TV, CTv, and EFv were 6.42 cm 3  ± 6.57 (range: 0.5-39.37 cm 3 ), 6.24 cm 3  ± 6.15 (0.48-36.1 cm 3 ), and 8.98 cm 3  ± 9.96 (0.49-47.05 cm 3 ), respectively. When comparing TV to CTv, CCC was 0.99 (95% confidence interval [CI]: 0.99-0.995), indicating excellent agreement, although TV was slightly underestimated at larger volumes. When comparing TV to EFv, CCC was 0.82 (95% CI: 0.78-0.86), indicating poor agreement. EFv tended to overestimate the TV, especially as stone volume increased beyond 1.5 cm 3 , and there was a significant spread between trials., Conclusions: An automated CT-based algorithm more accurately and reliably estimates stone volume than does the ellipsoid formula. While further research is necessary to validate stone volume as a surrogate for stone burden, CT-based algorithmic volume measurement of urinary stones is a promising technology.

Urethral diverticulum of the male is uncommon. We report a case of bulbar urethraldiverticulum with contained giant calculus presenting as left inguino-scrotal swellingsecondary to peri-urethral abscess in a 40 year-old male. In the light of this case Weemphasize the importance of investigation for the presence of urethral diverticulum in youngmale individuals presenting with voiding disturbances to preventrelated complications.

Objective: To evaluate trends in the incidence of kidney stones and characteristics associated with changes in the incidence rate over 3 decades., Patients and Methods: Adult stone formers in Olmsted County, Minnesota, from January 1, 1984, to December 31, 2012, were validated and characterized by age, sex, stone composition, and imaging modality. The incidence of kidney stones per 100,000 person-years was estimated. Characteristics associated with changes in the incidence rate over time were assessed using Poisson regression models., Results: There were 3224 confirmed symptomatic (stone seen), 606 suspected symptomatic (no stone seen), and 617 incidental asymptomatic kidney stone formers. The incidence of confirmed symptomatic kidney stones increased from the year 1984 to 2012 in both men (145 to 299/100,000 person-years; incidence rate ratio per 5 years, 1.14, P<.001) and women (51 to 217/100,000 person-years; incidence rate ratio per 5 years, 1.29, P<.001). Overall, the incidence of suspected symptomatic kidney stones did not change, but that of asymptomatic kidney stones increased. Utilization of computed tomography for confirmed symptomatic stones increased from 1.8% in 1984 to 77% in 2012; there was a corresponding higher increased incidence of symptomatic small stones (≤3 mm) than of larger stones (>3 mm). Confirmed symptomatic kidney stones with documented spontaneous passage also increased. The incidence of kidney stones with unknown composition increased more than that of stones with known composition., Conclusion: The incidence of both symptomatic and asymptomatic kidney stones has increased dramatically. The increased utilization of computed tomography during this period may have improved stone detection and contributed to the increased kidney stone incidence., (Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Clinical suspicion of urolithiasis should be evaluated with low-dose computed tomography as the first-line imaging modality for nonpregnant, adult patients. A period of observation may be appropriate for ureteral stones less than 10 mm, and medical expulsive therapy may be beneficial for facilitating passage of distal ureteral stones. Regardless of stone type, patients should adhere to a low-sodium diet and attempt to achieve a urine volume of more than 2.5 L daily. Individuals with calcium stones should maintain a normal calcium diet, and if stones persist, citrate therapy or thiazide diuretics in the setting of hypercalciuria may be indicated., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: An accurate urinary predictor of stone recurrence would be clinically advantageous for patients with cystinuria. A proprietary assay (Litholink, Chicago, Illinois) measures cystine capacity as a potentially more reliable estimate of stone forming propensity. The recommended capacity level to prevent stone formation, which is greater than 150 mg/l, has not been directly correlated with clinical stone activity. We investigated the relationship between urinary cystine parameters and clinical stone activity., Materials and Methods: We prospectively followed 48 patients with cystinuria using 24-hour urine collections and serial imaging, and recorded stone activity. We compared cystine urinary parameters at times of stone activity with those obtained during periods of stone quiescence. We then performed correlation and ROC analysis to evaluate the performance of cystine parameters to predict stone activity., Results: During a median followup of 70.6 months (range 2.2 to 274.6) 85 stone events occurred which could be linked to a recent urine collection. Cystine capacity was significantly greater for quiescent urine than for stone event urine (mean ± SD 48 ± 107 vs -38 ± 163 mg/l, p <0.001). Cystine capacity significantly correlated inversely with stone activity (r = -0.29, p <0.001). Capacity also correlated highly negatively with supersaturation (r = -0.88, p <0.001) and concentration (r = -0.87, p <0.001). Using the suggested cutoff of greater than 150 mg/l had only 8.0% sensitivity to predict stone quiescence. Decreasing the cutoff to 90 mg/l or greater improved sensitivity to 25.2% while maintaining specificity at 90.9%., Conclusions: Our results suggest that the target for capacity should be lower than previously advised., (Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Introduction: The incidence of urolithiasis in the pediatric population in the United States has steadily been increasing over the past few decades. Few studies to date have examined trends in the hospitalization and inpatient surgical treatment of urolithiasis in the pediatric population using nationally representative data., Objective: The aim was to evaluate nationwide trends in the rates of pediatric hospitalization and inpatient surgical activity for upper urinary tract calculi (UUTC) in the United States from 2001 to 2014., Patients and Methods: The National Inpatient Sample (NIS) databases for 2001-2014 were queried. Hospitalizations for patients younger than age 18 (excluding newborns), with principal discharge diagnoses of kidney or ureteral calculi were selected. Surgical procedures during hospitalization were identified. Hospitalization and surgical activity data were analyzed using trends tests, chi-square statistics, and multivariable logistic regression as appropriate., Results: Of an estimated 30.2 million pediatric hospitalizations during the study period, 44,369 overall (147 per 100,000) were for UUTC. The total number and proportion of UUTC hospitalizations per 100,000 all-cause admissions significantly decreased between 2001 and 2014 (p < 0.0001) (figure). Surgical intervention was undertaken in 19,946 (45%) of UUTC hospitalizations, with significantly increasing frequency over the study interval (p < 0.0001). Urinary tract drainage was the most frequently performed surgical intervention. On multivariable analysis, significant predictors of a higher likelihood of undergoing inpatient surgical intervention during hospitalization for UUTC included older age, female gender, deficiency anemias, hypertension, neurologic disorders, paralysis, and hospitalization after 2001., Discussion: The declining trend in hospitalization for UUTC likely reflects a shift toward outpatient care for routine cases, reserving hospitalization for sicker patients or those with complications of urolithiasis. Similar to previous studies, we also observed that girls were significantly more likely than boys to be hospitalized for stone disease, and that majority of the stone activity in the pediatric population was in children aged 15-17 years. We also observed a sharp increase in the proportion of hospitalized patients who underwent surgical intervention between 2001 and 2014, but the primary driver of this trend remains uncertain., Conclusion: Pediatric hospitalizations for UUTC in US children significantly decreased between 2001 and 2014, while of those hospitalized the proportion who underwent stone-related surgical intervention significantly increased over the same period. A shift towards outpatient care, reserving hospitalization and inpatient surgical care for sicker patients, those with urolithiasis-related complications, or those who fail conservative management, is a possible explanation for these observed trends., (Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Introduction: Currently, stone size cannot be accurately measured while performing flexible ureteroscopy (URS). We developed novel software for ureteroscopic, stone size measurement, and then evaluated its performance., Methods: A novel application capable of measuring stone fragment size, based on the known distance of the basket tip in the ureteroscope's visual field, was designed and calibrated in a laboratory setting. Complete URS procedures were recorded and 30 stone fragments were extracted and measured using digital calipers. The novel software program was applied to the recorded URS footage to obtain ureteroscope-derived stone size measurements. These ureteroscope-derived measurements were then compared with the actual-measured fragment size., Results: The median longitudinal and transversal errors were 0.14 mm (95% confidence interval [CI] 0.1, 0.18) and 0.09 mm (95% CI 0.02, 0.15), respectively. The overall software accuracy and precision were 0.17 and 0.15 mm, respectively. The longitudinal and transversal measurements obtained by the software and digital calipers were highly correlated (r = 0.97 and 0.93). Neither stone size nor stone type was correlated with error measurements., Conclusions: This novel method and software reliably measured stone fragment size during URS. The software ultimately has the potential to make URS safer and more efficient.

The aim of the present meta-analysis was to systematically examine the literature and to identify of the results of randomized controlled trials (RCTs) comparing the efficacy and safety of regional anesthesia (RA) versus general anesthesia (GA) for percutaneous nephrolithotomy (PCNL). An exhaustive electronic literature search of PubMed, Embase, and Web of science was performed until March 2018. Nine prospective RCTs concluding 858 patients comparing the use of RA to GA for PCNL were included. Combined results demonstrated that PCNL under RA could reduce operative time (mean difference [MD] -6.20; 95% CI -10.39 to -2.01), hospital stay (MD -0.59; 95% CI -0.74 to -0.45), visual analgesic score on the first and third postoperative day (MD -2.62, 95% CI -3.04 to -2.19 and MD -0.38; 95% CI -0.58 to -0.18) , analgesic requirements (MD -36.84; 95% CI -55.23 to -18.45), and nausea and/or vomiting (relative risk [RR] 0.28; 95% CI 0.13-0.61). There were no significant differences between RA and GA groups in terms of stone-free rate, blood transfusion, and postoperative fever rate. The results of subgroup analysis were basically consistent with the overall findings. Current evidence suggests that RA is an available and safe option in carefully evaluated and selected patients., (© 2018 S. Karger AG, Basel.)

Introduction: Cystine stone is the only clinical manifestation in patients with cystinuria, which is an autosomal recessive inheritable disease. However, clinical and genetic data vary among patients in different countries., Objective: To investigate the characteristics of Chinese pediatric cystine stone patients., Patients and Methods: Thirteen pediatric patients with cystine stones were evaluated in our clinic between 2012 and 2015. Gene mutations in SLC3A1 and SLC7A9 were investigated. Metabolic evaluation was also performed. Thirteen pediatric patients with calcium oxalate stones were selected as controls., Results: Of these patients, eight were males and five were females. Average age at detection of the first stone was 6.8 ± 5.2 years. Urinary stones in three of the 13 cystine patients were composed of cystine and calcium oxalate. The 63.6% of patients with upper urinary stones had bilateral stones. A total of 17 different missense mutations were identified, and 12 of these mutations were first reported in this study. Metabolic abnormalities could be detected in 77% of cystine stone patients. The most common metabolic abnormality was hyperoxaluria, followed by hypercalciuria and hypocitraturia. Compared with calcium stone patients, our cystine stone patients had a higher rate of bilateral stones, larger stone size, higher levels of serum BUN and Cr, urine citrate excretion (Table), and higher mean value of surgeries per patient. By contrast, the opposite was true for urine oxalate excretion and AP (CaOx) index EQ. The urine excretion of cystine was not correlated with other urinary constituents., Discussion: Patients with cystinuria frequently suffer recurrent renal stones and may subsequently need a series of stone removal procedures during their lifetime. This condition is likely to affect their overall renal function. SLC3A1 and SLC7A9 have been extensively investigated, but a detection rate of 100% in cystinuric patients has yet to be obtained. In our study, we found 14 missense mutations in 18 of 26 alleles except four mutation polymorphisms. Most of the gene mutations found in our study were their first reports. Metabolic abnormalities were frequently found in cystine stone patients, but their risk of calcium oxalate stone formation was relatively lower than that of patients with calcium oxalate stones., Conclusions: Cystine stone patients are at risk of impaired renal function and the formation of calcium oxalate stones. Most of the gene mutations identified in our patients were first reported in this study. Therefore, cystinuria possibly exhibits genetic and allelic heterogeneity in Chinese pediatric cystine stone patients., (Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Background: Chemical composition of stones is one of the important diagnostic criteria for aetiology of stone formation and treatment to prevent recurrence. This paper reports composition of stones in children at a tertiary hospital by Fourier Transformation Infrared Spectroscopy (FTIR)., Methods: Between January-June 2015, 412 urinary stones from children were analysed by FTIR. Chi-square tests were used for the comparison of categorical measurements between groups. All reported values were 2-sided and statistical significance was considered at p-value ≤0.05., Results: Of the 412 stones, 263 (63.8%) were renal, 101(24.5%) bladder and 48 (11.7%) ureteric. The mean age of children was 7.15±4.13 years with a M:F ratio 2.4:1. Of the 412 stones, 144(34.9%) were pure stones composed of one compound and 268(65.1%) were mixtures. Frequency of compound in stones was Ammonium Acid Urate (AAU) (65%), Calcium Oxalate (CaOx) (76.9%), Uric Acid (5%), Calcium Phosphate Apatite (7%), Whitlockite (8.4%), Struvite (4%), Cystine (0.72%) and Xanthine (2.11%). Frequency of compounds analysed in three ages groups 0-5, 6-10 and 11-15 years showed high frequency of AAU (73%) in 0-5 years as compared to (60%) in 11-15 years (p<0.018). CaOx (90%) in 11-15 as compared to (62.5%) in 0-5 years (p<0.001). Bladder stones were more prevalent in children 0-5 years (32%) vs 19% in 11-15 years (p<0.004) while renal were 75% in 11-15 years and 54% in 0-5 years (p<0.04)., Conclusions: AAU stones known to be associated with malnutrition and chronic diarrhoea are highly prevalent in paediatric stones formers in our population in the kidney, bladder and ureter.

Objective: The aim of this study was to compare the biochemical parameters of the urine and blood in spinal cord injury (SCI) patients and healthy subjects., Methods: Thirty male patients with SCI were enrolled. Biochemical features of the urine and blood of the SCI patients were compared to healthy subjects. Extracted stones were analyzed by X-ray diffraction., Results: A total of 30 patients with SCI (mean age of 28.77 ± 7.3 years) and 10 healthy subjects (mean age of 27.6 + 6.2 years) were included. Among the patients with SCI; 12 of them (40%) had urinary stones and 18 of them (60%) did not. Urinary stone was localized in the kidneys and bladder in 25% and 75% of the subjects, respectively. The mean duration of cord injury at diagnosis of urinary stone was 9.2 ± 6 months. Urine cultures obtained on admission were negative for the control group, while the microorganism isolation rate was 73.3% in the SCI group. The urinary excretion of citrate and Mg were lower in the patient group compared with control group (p= 0.008, p= 0.001, respectively). As for the diffraction analysis of eight stones; five (62.5%) of the stones were calcium oxalate, two (25%) of them were calcium phosphate, and one (12.5%) was magnesium ammonium phosphate., Conclusion: Both infection and metabolic changes play an important role in stones formation in SCI patients. The urinary excretion of citrate and Mg was decreased and urinary PH was increased in SCI patients.

Purpose: The prevalence of urinary stone disease is increasing in children. We previously reported a high rate of urinary metabolic abnormalities, including hypercalciuria and hypocitraturia, in stone forming children. In this study we determined whether calcium-to-citrate ratio could help predict those at risk for recurrent stone formation., Materials and Methods: We conducted a retrospective cohort study to assess calcium-to-citrate ratios in children with urolithiasis. Two 24-hour urine collections were performed. Urinary excretions of calcium and citrate were analyzed, and calcium-to-citrate ratio was calculated. Patients were stratified into solitary and recurrent stone formers and compared to a control group of normal children., Results: We identified 73 solitary and 92 recurrent stone formers. Mean patient age was 13 years for both groups. Gender was well matched. A total of 29 normal children served as controls. Mean calcium-to-citrate ratio was 0.41 in solitary stone formers and 0.64 in recurrent stone formers (p = 0.02). Mean value in normal children (0.33) was significantly less compared to recurrent stone formers (p = 0.002) and trended lower compared to solitary stone formers (p = 0.15). The ratio was abnormally high in recurrent stone formers (70%) compared to solitary stone formers (47%, p = 0.003)., Conclusions: There are significant differences in urine calcium-to-citrate ratios between solitary and recurrent calcium stone forming children. Solitary stone formers trended higher compared to controls. These findings may allow more precise risk stratification and treatment to prevent recurrent stone episodes., (Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Introduction: Prevalence of urinary calculi in children has been increasing in the past years. We performed an analysis of the chemical composition of stones formers of the pediatric population in our geographical area over the years 2005 to 2013., Materials and Methods: Fourier transform infrared spectroscopy was employed for the determination of the calculus composition of a group of Sicilian children, and metabolic studies were performed to formulate the correct diagnosis and establish therapy., Results: The prevalence of stone formation was much higher for boys than for girls, with a sex ratio of 1.9:1. The single most frequent component was found to be calcium oxalate monohydrate, and calcium oxalates (pure or mixed calculi) were the overall most frequent components. Calcium phosphates ranked 2nd for frequency, most often in mixed calculi, while urates ranked 3rd. The metabolic disorder most often associated with pure calcium oxalate monohydrate calculi was hypocitraturia, while hyperoxaluria was predominantly associated with calcium oxalate dihydrate calculi., Conclusions: Mixed calculi had the highest prevalence in our pediatric population. Our data showed that Fourier transform infrared spectroscopy was a useful tool for the determination of the calculi composition.

Analysis of the composition of a urinary stone is one of the most important steps in the clinical management of patients with urolithiasis. Fourier transform infrared spectroscopy, X-ray diffractometry and petrographic microscopy are the techniques currently used. Novel technical developments in recent years - such as Raman spectroscopy and hyperspectral imaging - have resulted in new approaches to improve urinary stone analysis. In future, table-top portable systems may be used that allow stones to be rapidly examined directly after the operation. These systems may even be integrated into lithotripsy laser systems., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: Chronic unilateral hematuria (CUH) is also called lateralizing essential hematuria, benign essential hematuria, and benign lateralizing hematuria, which was defined as intermittent or continuous gross hematuria that cannot be diagnosed with standard radiology and hematology studies, together with unilateral bloody efflux by cystoscopy. CUH is rare, but sometimes confused with malignancy or life-threatening hemorrhage. Therefore, it can cause considerable anxiety to not only patients but also urologists. For this study, we summarized articles about endoscopic diagnosis and treatment of CUH, and discussed the development of endourology for CUH., Materials and Methods: We searched articles related to CUH that were indexed in the PubMed database and published in English. Key terms used were "unilateral," "lateralizing," "chronic," "benign," and "idiopathic" hematuria. We found 15 pertinent articles reporting CUH., Results: Endoscopically, CUH can be classified into three categories: discrete lesion, diffuse lesion, or no (unidentified) lesion. Currently, endoscopic techniques for CUH are similar to the techniques for upper tract urothelial carcinoma, using semi-rigid and flexible ureteroscopes with diathermy fulguration or laser ablation for treatment. The overall success rate of endoscopic treatment for CUH, defined as resolution of gross hematuria after treatment, was 93% (190/205). The recurrence rate, defined as recurrent gross hematuria after treatment, was 10% (19/189)., Conclusion: Advancements in endoscopic devices and techniques have enabled more accurate and less invasive diagnosis and treatment of CUH. Once CUH is defined, flexible ureteroscopy is the diagnostic and therapeutic technique of choice.

The article describes a clinical observation of a 68 y/o patient with large stones of the urethra, reaching 5 cm in length and located in the penile urethra. The patient underwent a three-stage treatment: the first stage consisted of drainage of the urinary bladder, the second stage of the urethrolithotomy and a double-barreled fistula, the third was an anastomotic urethroplasty. After removing the cystostomic drainage tube, normal urination was restored.

Backgroud: This research studies if Hounsfield density of urinary stone can be predicted without computerized tomography (CT) caused by because increased radiation exposure in follow-up of patients., Methods: The records of patients with renal or ureteral stone were analyzed retrospectively for the time period between November 2013 and April 2014. The inclusion criteria defined were: no multiple stones; stone size ≥3 mm; presence of renal and ureteral stones; absence of staghorn stone. All CT images were assessed in abdominal windows by a single radiologist. Hounsfield Unit (HU) value of CT was used to interpret the density of the stone. The density of the stone was measured in the longest axis of the stone center (core) and the edges (periphery) of each stone. Biochemical analysis of spot urine calcium (Ca) and uric acid (UA) was done at the time of diagnosis. Correlation and linear regression analysis was performed., Results: Forty patients were included the study and median age of patients is 22 (IQR 21-28). Since the unit was a military hospital, most patients admitted to hospital were young male conscripts with low median age. It has been found that spot urine uric acid and uric acid/Ca ratio is associated with stone density as HU (P=0.004, P<0.001). Although predictive value appeared low, linear regression model statistically predicted stone density as HU (P<0.001 R2=0.32). Stone size has proved to be positively correlated with stone density (P<0.001)., Conclusions: Despite the predictive value of urine analysis model is low, it may be considered to predict HU attenuation of stone. Spot urine analysis of calcium and uric acid may be helpful for both diagnosis and follow-up. We believe that controlled studies with larger patient populations will provide further insights into this issue.

We report a rare case of nephrocalcinosis caused by hereditary renal hypouricaemia 3 months after kidney transplantation. A 41-year-old man who underwent living-related kidney transplantation from his father was admitted to our hospital for a protocol biopsy; he had a serum creatinine (S-Cr) of 1.37 mg/dL and no proteinuria. Histologically, there was no evidence of rejection or calcineurin inhibitor toxicity, although scattered nephrocalcinosis was observed in the distal tubules. Perioperatively, the patient had a serum uric acid (S-UA) of 1.9 mg/dL with a fractional excretion of uric acid (FEUA) of 29% (normal, <10%) and UA clearance of 26.8 mL/min (normal, 7.3-14.7 mL/min) 3 days after kidney transplantation. The donor also had a relatively low S-UA of 2.4 mg/dL and high FEUA of 10.3%. Subsequent DNA direct sequencing followed by restriction fragment length polymorphism revealed that both the recipient's and donor's urate transporter 1 (URAT1) gene had a heterozygous nonsense mutation in exon 5 (C889T). Further, the immunoreactivity of antibodies for the C terminus of URAT1 revealed a partial deletion. De Galantha and von Kossa staining revealed that the nephrocalcinosis was due to urate crystals and calcium stones. Therefore, we diagnosed hereditary renal hypouricaemia. We directed the patient to avoid hard exercise, drink plenty of water, and alkalize the urine. The 1-year follow-up allograft biopsy showed no evidence of nephrocalcinosis in the distal tubules. This is the first report of nephrocalcinosis in the distal tubules as a diagnostic clue to hereditary renal hypouricaemia. We also review the related literature., (© 2016 Asian Pacific Society of Nephrology.)

Objectives: To determine the feasibility of crystalluria as a biomarker for stone disease in patients with cystinuria., Patients and Methods: All patients attending a multidisciplinary cystinuria clinic provided early morning urine (EMU) and clinic urine (CU) samples for crystal measurement over a 2-year period (August 1, 2010, to July 31, 2012). Association between presence of crystals, presence of stone(s), and new stone growth (NSG) was determined using the chi-square test. Crystal numbers in EMU and CU were compared in patients with stones/NSG and no stones/stable disease using the Mann-Whitney U test., Results: There was a statistically significant difference between the presence of crystalluria and presence of stones for CU (chi-square test = 5.86, df = 1, p = 0.02) but not EMU (chi-square test = 1.92, df = 1, p = 0.17) and between the presence of crystalluria and NSG for CU (chi-square test = 8.10, df = 1, p = 0.004) but not EMU (chi-square test = 1.32, df = 1, p = 0.25). Patients with stones and NSG have higher levels of crystalluria in CU than patients with no stones or stable disease (stones, median = 41, interquartile range [IQR] = 600 vs median = 0, IQR = 21, p = 0.01; NSG, median = 49, IQR = 525 vs median = 0, IQR = 40, p = 0.01)., Conclusion: The presence of crystalluria in CU samples is associated with the presence of stones. Crystalluria is comparable to ultrasound and may serve as a useful adjunct to predict whether a patient with cystinuria has stones, which could guide the frequency of clinic review and imaging.

Introduction: Recent evidence would suggest a low rate of metabolic assessment in stone formers, even in those deemed as high risk. We wished to assess the attitudes and practice patterns of metabolic work up in North American members of the Endourological Society as part of the management of stone-forming patients., Methods: A 12-question online multiple-choice questionnaire (using Survey Monkey(®)) was distributed to all members of the Endourological Society through e-mail. Descriptive analyses were performed., Results: A total of 124 North American members of the Endourological Society responded (90% endourologists, 65% fellowship trained). Ninety-seven percent perform metabolic assessments without referring to a consultant. Eighty-three percent use a commercial analysis company and 17% request serum or urine parameters individually. Ninety-seven percent believe that 24-48-hour urine collection is a better way of assessing patients for metabolic abnormalities than a "basic analysis." Many respondents (37%) would be more likely to metabolically assess if results were easier to interpret, and 35% would like assistance/advice in the interpretation of results. At initial investigation of a first-time stone former, 87% of respondents use serum chemistry, 48% use 24-hour urine, 26% use 48-hour urine (two consecutive 24-hour urine collections), 54% send stone for analysis, and 7% do not investigate. On recurrent stone formers, 69% use serum chemistry, 73% use 24/48-hour urine, and 23% send stone for analysis. On routine follow-up, 36% check serum chemistry, 55% use 24-hour urine, 2% use 48-hour urine, and 29% do not metabolically evaluate. The majority agree that pharmacologic therapy plays a strong role in preventing recurrence (90%). After initiating pharmacologic therapy, 59% reassess using serum chemistry and 84% and 7% use 24/48-hour urine collection, respectively. Physicians re-evaluate patients after 1 month (7%), 1-2 months (10%), 2-4 months (44%), 4-6 months (30%), or after 6-12 months (7%)., Conclusion: This snapshot assessment of Endourological Society members' practices in the metabolic investigation of stone-forming patients demonstrates wide testing variations. Many physicians expressed interest in assistance/advice in the interpretation of the metabolic assessment results.

Objective: The aim of this study is to analyze urine concentrations (mg/dl) of different lithogenic factors in a sample of 24 h as a predictor of these changes rather than absolute values depend on the volume of diuresis., Methods: A total of 131 patients from the North Almeria Health Management Area (Spain) with urinary calstone disease in whom a metabolic study was indicated were included from June 2014 to May 2015. The concentrations of calcium, oxalate, uric acid, citrate and magnesium were measured in the urine, and the calcium/citrate ratio was calculated. The classifications used were: hypercalciuria (>260mg/24h), hyperuricosuria (>750mg/24h), hyperoxaluria (>40mg/24h), hypocitraturia (<320mg/24h) and hypomagnesuria (<35mg/24h). The statistical analysis was performed using SPSS 17.0., Results: A cut-off point of 12.55mg/dl, with a sensitivity of 90% and a specificity of 85% and a relative risk (RR) of 51.2 (13.9-188.4), was estimated for urinary calcium. For oxalate the cut-off point was 1.86mg/dl, with a sensitivity of 91% and a specificity of 84% with an estimated RR of 67.2 (8.3-540.6). As regards the uric acid concentration in urine, a cut-off point of 31.2mg/dl was estimated, with a sensitivity of 85% and a specificity of 70% and a RR of 12 (3.8-37.6). For citrate the cut-off point was 18.8mg/dl, with a sensitivity and specificity of 82% and 74%, respectively, with a RR of 13.7 (4.4- 42.6). The cut-off point for magnesium was 2.26mg/dl with a sensitivity of 95% and specificity of 78%, with a RR of 67.6 (11.4-398.3)., Conclusion: The determination of urine concentrations, instead of absolute values, depends to a large extent on urine output, appears to be useful when estimating classic metabolic alterations and should be taken into account in the evaluation of patients with urinary stone disease.

Purpose: Shock-wave lithotripsy (SWL) is accepted as the first line treatment modality for uncomplicated upper urinary tract stones; however, validated prediction models with regards to stone-free rates (SFRs) are still needed. We aimed to develop nomograms predicting SFRs after the first and within the third session of SWL. Computed tomography (CT) information was also modeled for constructing nomograms., Materials and Methods: From March 2006 to December 2013, 3028 patients were treated with SWL for ureter and renal stones at our three tertiary institutions. Four cohorts were constructed: Total-development, Total-validation, CT-development, and CT-validation cohorts. The nomograms were developed using multivariate logistic regression models with selected significant variables in a univariate logistic regression model. A C-index was used to assess the discrimination accuracy of nomograms and calibration plots were used to analyze the consistency of prediction., Results: The SFR, after the first and within the third session, was 48.3% and 68.8%, respectively. Significant variables were sex, stone location, stone number, and maximal stone diameter in the Total-development cohort, and mean Hounsfield unit (HU) and grade of hydronephrosis (HN) were additional parameters in the CT-development cohort. The C-indices were 0.712 and 0.723 for after the first and within the third session of SWL in the Total-development cohort, and 0.755 and 0.756, in the CT-development cohort, respectively. The calibration plots showed good correspondences., Conclusions: We constructed and validated nomograms to predict SFR after SWL. To the best of our knowledge, these are the first graphical nomograms to be modeled with CT information. These may be useful for patient counseling and treatment decision-making.

Objectives: Damage and detachment of podocytes and loss into the urine have been implicated in the progression of kidney diseases. The purpose of this study was to investigate the potential role of urine cytology based on SurePath(™) combined with immunoenzyme staining using Wilms' tumour 1 (WT1) antibody as a podocyte marker in the discrimination of normality and non-renal urinary tract disease from kidney disease., Methods: Sixty-six patients with kidney disease, 45 patients with lower urinary tract disease and 30 healthy volunteers were examined. Urine cytology slides were prepared using the SurePath method and immunoenzyme stained with WT1 antibody, and the number of WT1-positive cells was counted., Results: In kidney disease, WT1-positive cells were found in 33 (50%) of 66 samples. No WT1-positive cells were found in 45 patients with lower urinary tract disease or in 30 healthy volunteers. The positive rates for WT1 varied with disease type, but not significantly: immunoglobulin A (IgA) nephropathy, (14/23); membranous glomerulonephritis, (4/10); Henoch-Schönlein purpura nephritis, (3/5); diabetic glomerulopathy, (5/5); minor glomerular abnormality/minimal change nephrotic syndrome (0/4)., Conclusions: The results suggest that WT1 immunoenzyme staining of urine cytology can be used to detect some types of kidney disease., (© 2015 John Wiley & Sons Ltd.)

In 2015, population-based studies in patients with urinary stones informed us of the changing trends in contemporary stone management and identified areas for improvement. Although meta-analyses aim to provide the highest level of evidence, a randomized controlled trial of medical expulsive therapy challenged current paradigms and was the defining publication of the year.

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., (Published by Elsevier Inc.)

Infected kidney stones refer to stones that form because of urinary tract infections with urease-producing bacteria, secondarily infected stones of any composition, or stones obstructing the urinary tract leading to pyelonephritis. The mainstay of treatment of infection stones is complete stone removal. Kidney stones that obstruct the urinary tract and cause obstructive pyelonephritis are also frequently referred to as infected stones. Obstructive pyelonephritis is a urologic emergency as it can result in sepsis and even death. Infection stones and obstructive stones causing pyelonephritis are different disease processes, and their workup and management are described separately., (Copyright © 2015 Elsevier Inc. All rights reserved.)