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Adult nephrologists often look after patients who have been diagnosed with kidney disease in childhood. This does present unique challenges to the adult nephrologist, who may be unfamiliar with the underlying cause of kidney disease as well as the complications of chronic kidney disease (CKD) that may have accumulated during childhood. This review discusses common causes of childhood CKD, in particular congenital anomalies of the kidney and urinary tract (CAKUT), autosomal dominant tubulointerstitial kidney disease (ADTKD), polycystic kidney disease, hereditary stone disease, nephrotic syndrome and atypical haemolytic uraemic syndrome. The long-term consequences of childhood CKD, such as the cardiovascular consequences, cognition and education as well as bone health, nutrition and growth are also discussed.

To evaluate the impact of chronic stone recurrence on an individual's quality of life using the validated Wisconsin Stone Quality of Life (WISQOL) questionnaire. We collected cross-sectional data on patients with kidney stones from 14 institutions in North America. A stone event was defined as renal colic, stone-related procedure or emergency department visit. The regression analyses using general linear models and pairwise comparison determined the impact of the number of stone events on quality of life. The median number of stone events among the 2205 patients who completed the questionnaire was 3 (IQR 1-6). The mean total score was 107.4 ± 28.7 (max 140 points). The number of lifetime stone events was an independent predictor of lower quality of life (p 0.001), specifically, score declined significantly beyond five events. Compared with patients who experienced a single stone event, there was a 0.4, 2.5, and 6.9 point decline in the adjusted mean WISQOL score after 2-5, 6-10, or 10 events, respectively. The cumulative number of lifetime stone events was associated with a lower quality of life when more than five stone events were occurred. These findings underscore the importance of efforts to determine the underlying metabolic etiology of urolithiasis in the recurrent stone former, and the institution of a regimen to place their stone disease in remission.

The prevalence of urolithiasis in humans is increasing worldwide; however, nonsurgical treatment and prevention options remain limited despite decades of investigation. Most existing laboratory animal models for urolithiasis rely on highly artificial methods of stone induction and, as a result, might not be fully applicable to the study of natural stone initiation and growth. Animal models that naturally and spontaneously form uroliths are an underused resource in the study of human stone disease and offer many potential opportunities for improving insight into stone pathogenesis. These models include domestic dogs and cats, as well as a variety of other captive and wild species, such as otters, dolphins, and ferrets, that form calcium oxalate, struvite, uric acid, cystine, and other stone types. Improved collaboration between urologists, basic scientists, and veterinarians is warranted to further our understanding of how stones form and to consider possible new preventative and therapeutic treatment options.

The authors aimed to evaluate the factors affecting clinical outcomes of cystine stone disease in children and to understand the change in disease management over time. Between January 1991 and September 2017, the demographic and clinical data of pediatric patients with documented cystine stone disease were retrospectively analyzed. Patients with at least 12-month follow-up were included. Disease management and clinical outcomes were compared between the first and second 35 patients managed during the study's time frame. A total of 70 patients were included. The female to male ratio was 30/40. The mean age and follow-up period was 29.8 ± 40.1 months and 106.5 ± 56 months, respectively. The mean initial procedure number to treat the first stone episode was 2.4 ± 1.6. Single stone and single affected site were significant predictors for stone clearance. Overall, patients underwent a mean of 5.5 procedure during their follow-up. Recurrence was detected in 71.4% (50/70) of patients. Residual fragments and non-compliance to medical treatment after the initial intervention were significant predictors for recurrence within shorter interval period. 31.4% (22/70) of patients had renal atrophy during follow-up. They were older at the initial diagnosis and had average urine pH lower than 7.5. The first 35 patients had more open procedures. Still, they had more recurrence rate and tend to have more renal atrophy. As a conclusion, cystine stone disease has a recurrent course in children. Stone and fragments entirely removed (SaFER) concept with all minimally invasive methods available and strict follow-up should be the basis for any management plan.

To evaluate the feasibility of measuring the intrapelvic pressure (IPP) during f-URS with a wire including a pressure sensor and to assess IPP profiles during the procedure. Patients undergoing f-URS for stone disease were recruited. A wire with pressure sensor was placed in the renal cavities to measure IPP. For these cases, either no ureteral access sheath (UAS) or 10/12 or 12/14-Fr UASs were used according to surgeon discretion. Irrigation was ensured by a combination of a continuous pressure generator set at 80 cmH2O and a hand-assisted irrigation system providing on-demand forced irrigation to provide proper visibility. Pressures were monitored in real time and recorded for analysis. Four patients undergoing five f-URS were included. IPP monitoring was successful in all patients. Mean baseline IPP was 6 cmH2O. During f-URS with only the endoscope in the renal cavities and irrigation pressure set at 80 cmH2O without any forced irrigation, the mean IPP was 63 cmH2O. Mean IPP during laser lithotripsy with the use of on-demand forced irrigation was 115.3 cmH2O. The maximum pressure peaks recorded during this therapeutic period using forced irrigation ranged from 289.3 to 436.9 cmH2O. High IPP levels may be achieved during f-URS with on-demand irrigation systems. The impact of these high pressures on the risk of complications and long-term consequences still need to be evaluated adequately. But, in this preliminary pilot study, IPP could be reliably and conveniently monitored and recorded using a wire with a digital pressure sensor.

The gold standard for urologic management of large stone disease traditionally has been percutaneous nephrolithotomy (PCNL). An alternative to PCNL is robotic pyelolithotomy (RP), which continues to gain traction. This study is a retrospective review of ten cases performed over a 2 year period presenting operative outcomes for large stone disease treated with RP. The mean and standard deviation were calculated for age, body mass index, stone volume, stone diameter, pre-operative creatinine, operative time, robot-docked time, length of stay, post-operative creatinine, and estimated blood loss. In addition, results were collected for post-operative complications and secondary procedure requirements. Complete stone clearance was successful in 9 of 10 cases. The average renal function remained stable from a pre-operative creatinine of 0.917 mg/dL to a post-operative creatinine level of 0.943 mg/dL. This case series demonstrates that robotic assisted surgery has practical application when managing large stone disease.

Purpose of Review To highlight and review the application of artificial intelligence (AI) in kidney stone disease (KSD) for diagnostics, predicting procedural outcomes, stone passage, and recurrence rates. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. Recent Findings This review discusses the newer advancements in AI-driven management strategies, which holds great promise to provide an essential step for personalized patient care and improved decision making. AI has been used in all areas of KSD including diagnosis, for predicting treatment suitability and success, basic science, quality of life (QOL), and recurrence of stone disease. However, it is still a research-based tool and is not used universally in clinical practice. This could be due to a lack of data infrastructure needed to train the algorithms, wider applicability in all groups of patients, complexity of its use and cost involved with it. Summary The constantly evolving literature and future research should focus more on QOL and the cost of KSD treatment and develop evidence-based AI algorithms that can be used universally, to guide urologists in the management of stone disease.

To review the latest evidence about intrarenal pressures (IRPs) generated during flexible ureteroscopy (fURS) and mini percutaneous nephrolithotomy (mPCNL) and present tools and techniques to maintain decreased values. fURS and PCNL constitute the primary means of stone treatment. New flexible ureterorenoscopes with small diameter and miniaturized PCNL instruments achieve optimal stone-free rates (SFRs) while decreasing invasiveness and morbidity. Nevertheless, endourologists must remain cognizant regarding the dangers of increased IRPs to avoid complications. Current research presents essential information for urologists regarding this topic. During fURS, using a ureteral access sheath (UAS), we avoid extremely high IRPs with all irrigation types. During mPCNL, pressure remains low, mainly using the purging effect or a vacuum-assisted sheath. Devices of intraoperative IRP measurement and intelligent pressure control have proven their feasibility, accuracy and efficacy. These will have an increasing role to play in the future management of stone disease.

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

The present study aims to biochemically analyze the fluid samples containing stone dust taken during the perioperative period to determine the role of fluid in the prediction of stones in patients treated with ureterorenoscopic procedures. Our secondary aim is to investigate the role of both fluid analysis and stone analysis in predicting the results of the metabolic analysis. Comparative analyses were performed using fluid samples containing stone dust from 93 patients. Biochemical analysis of fluid containing stone dust was conducted; stone fragments were examined at a separate location using X-ray diffractometry(XRD). Metabolic analysis was performed to patients who provided stone-free status 1 month later. The results of chemical analysis were compared with the results of the XRD analysis. Patients’ stone type was determined with high accuracy using biochemical analysis. Differences were noted in ten patients following biochemical analysis and XRD analysis. Biochemical analysis predicted metabolic disorders in more patients than XRD analysis, particularly for those patients with multiple stone compositions. However, no significant differences between the results of biochemical and XRD analysis methods were found (κ = 0.27; p = 0.002). Moreover, biochemical analysis results revealed metabolic disorders in five patients; these findings were missed by XRD analysis. Biochemical analysis of fluid taken perioperatively during ureterorenoscopic laser lithotripsy to treat urinary system stone disease was found to determine stone composition with high accuracy. Biochemical analysis of fluid samples taken during the perioperative period is, thus, an easy, reliable and cost-effective test to assess stone composition in patients undergoing ureterorenoscopic procedures.

From health systems to individuals, nephrolithiasis is economically burdensome. The aim of the current paper is to characterize the financial burden of disease associated with nephrolithiasis with an emphasis on investigating treatment modality economic efficiency. For small volume practices and cases where there is high risk of scope damage, disposable flexible ureteroscope utilization seems to provide economic efficiency. The rise in global prevalence of stone disease is a large contributing factor to increasing costs associated with nephrolithiasis. A large proportion of costs from kidney stones stem from ED visits and inpatient care. There are opportunities to save money by transitioning care to outpatient settings in scenarios that allow such transition. Metaphylaxis and prevention strategies are effective at lowering costs in properly selected patient populations. Flexible ureteroscopy and percutaneous nephrolithotomy (PCNL) are the most economically efficient methods of surgically treating stone disease, with PCNL being reserved for large and lower pole stones. Time off work and other indirect costs, while challenging to quantify, are important considerations in the economics of nephrolithiasis.

The purpose of this study is to analyze clinical outcomes and costs of single-use flexible ureterorenoscopes in comparison with reusable flexible ureterorenoscopes in a tertiary referral center. Prospectively, 68 flexible ureterorenoscopies utilizing reusable (Flex-X2S, Flex-XC, Karl Storz) and 68 applying single-use flexible ureterorenoscopes (LithoVue, Boston Scientific) were collected. Clinical outcome parameters such as overall success rate, complication rates according to Clavien-Dindo, operation time and radiation exposure time were measured. Cost analysis was based on purchase costs and recurrent costs for repair and reprocessing divided by number of procedures. In each group 68 procedures were available for evaluation. In 91% of reusable and 88% of single-use ureterorenoscopies stone disease was treated with a mean stone burden of 101 ± 226 and 90 ± 244 mm2 and lower pole involvement in 47 and 41%, respectively (p > 0.05). Comparing clinical outcomes of reusable vs. single-use instruments revealed no significant difference for overall success rates (81 vs. 87%), stone-free rates (82 vs. 85%), operation time (76.2 ± 46.8 vs. 76.8 ± 40.2 min), radiation exposure time (3.83 ± 3.15 vs. 3.93 ± 4.43 min) and complication rates (7 vs. 17%) (p > 0.05). A wide range of repair and purchase costs resulted in total to $1212-$1743 per procedure for reusable ureterorenoscopy whereas price of single-use ureterorenoscopy was $1300-$3180 per procedure. The current work provided evidence for equal clinical effectiveness of reusable and single-use flexible ureterorenoscopes. Partially overlapping ranges of costs for single-use and reusable scopes stress the importance to precisely know the expenses and caseload when negotiating purchase prices, repair prices and warranty conditions.

The objective of this study is to evaluate the average radiation exposure in children with renal stones before SWL treatment. Mean radiation exposure values were evaluated in 110 children before SWL treatment. While some children referred to the emergency department (ED) with colic pain, remaining cases referred to outpatient department (OD). Although low-dose NCCT was performed in ED; KUB and abdominal sonography were first performed in other cases referring to OD where CT has been applied if needed. The type of imaging modality used and the mean radiation exposure were evaluated and comparatively evaluated with respect to the department referred, patient as well as stone related parameters. 49 children referred to ED and 61 children referred to OD. Mean stone size was 7.24 ± 0.29 mm. 62 cases had opaque stones. Mean radiation exposure values were higher in children referring to ED than the other cases. However, there was no significant difference between the two groups regarding the mean number of KUB, IVU and sonographic evaluation performed prior to SWL management. There was a significant correlation between the mean radiation exposure and the stone size as well degree of hydonephrosis in a positive manner. Although a significant correlation was present between the mean radiation exposure and stone opacity in a negative manner; there was no correlation with respect to the other related parameters. Unnecessary use of X-ray based imaging modalities in children could be effectively avoided using KUB and US combination beginning from the diagnostic phase of stone disease.

PURPOSE: To investigate the prospective outcomes of day-case ureterorenoscopy (DC-URS) for stone disease. With the rising prevalence of stone disease in the face of finite resources, there is increasing pressure to undertake procedures as a day case avoiding in-patient stay. There are a limited number of studies reporting on the feasibility of ureteroscopy as a day-case procedure. This study aimed to investigate the prospective outcomes and predictors precluding to DC-URS for stone disease in patients treated in our university teaching hospital.MATERIALS AND METHODS: Between March 2012 and July 2016, consecutive cases of adult stone ureteroscopy performed or supervised by a single surgeon were recorded in a prospective database. Patients underwent pre-operative counselling in a specialist stone clinic and were admitted to a dedicated 'Surgical day unit' on the day of surgery. A standardised anaesthetic protocol was adhered to in all cases. Data on patient demographics, stone parameters, pre-operative assessment, operative details, length of stay, stone-free rate and complication rates were collected and analysed.RESULTS: A total of 544 consecutive adult ureteroscopy for stone disease were conducted over the study period with a day-case rate of 77.7%. Thirty-nine percent of failed day-case ureteroscopy were due to late completion of ureteroscopy and due to associated social circumstances of patients. The mean stone size, operating time duration and post-operative stent insertion rates for DC-URS patients were 14 mm, 46 min and 96.5%, respectively. Post-operatively, the mean stone-free rate (SFR), unplanned re-admissions and complications for DC-URS patients were 95, 4 and 4%, respectively. A higher failure of DC-URS was related to patient's age (p = 0.003), positive pre-operative urine culture (p < 0.001), elevated pre-operative serum creatinine (p < 0.001) and higher mean operating time (p < 0.02).CONCLUSION: Based on our results, a day-case ureteroscopy rate of nearly 78% can be achieved. With its acceptable complication rate, and low re-admission rates, DC-URS is a safe and feasible option in a majority of patients with stone disease.

PURPOSE: The aim of this review was to provide current best evidence for evaluation, dietary, and medical management of patients with urolithiasis.METHODS: Literature addressing evaluation, dietary, and medical management of urolithiasis was searched. Papers were analyzed and rated according to level of evidence (LOE), whereupon a synthesis of the evidence was made. Grade of recommendation (GOR) was judged from individual clinical experience and knowledge of the evidence according to the Oxford Centre for Evidence-based Medicine.RESULTS: It is obvious that different stone diseases influence the life of stone-forming individuals very differently, and that evaluation and medical management should be personalized according to risk of recurrence, severity of stone disease, presence of associated medical conditions, and patient's motivation. With regard to evaluation, dietary and medical management of patients with urolithiasis evidence from the literature suggest that selective metabolic evaluation may lead to rational dietary and medical management. Statements based on LOE and GOR are provided to guide clinical practice.CONCLUSION: The provided evidence for evaluation of patients with urolithiasis aims at defining patients at high risk for recurrent/complicated stone disease. Based on this approach, evidence-based dietary and medical management regimes are suggested.

The rising prevalence of kidney stone disease is associated with significant costs to healthcare systems worldwide. This is in part due to direct procedural and medical management costs, as well as indirect costs to health systems, patients, and families. A number of manuscripts evaulating the economics of stone disease have been published since the 2008s International Consultation on Stone Disease. These highlight costs associated with stone disease, including acute management, surgical management, and medical management. This work hopes to highlight optimization in care by reducing inefficient treatments and maximizing cost-efficient preventative strategies.

Renal replacement lipomatosis (RRL) is an extremely rare condition. It is thought to be a spectrum of degenerative process classically characterized by extensive abundance of adipose tissue in kidney. RRL is associated with long standing inflammation and stone disease in 70% of cases. In severe cases, it may lead to complete parenchymal destruction. Rarely, RRL may mimic fatty neoplasm of kidney. We report a 62-year-old male with renal replacement lipomatosis associated with stone disease presenting as hematuria.

Technology for the treatment of stone disease has rapidly advanced, but a common nomenclature to communicate research and high-quality studies to assess treatment outcomes are lacking. Thus, guidelines are based on low-grade evidence and cannot make definitive recommendations in many scenarios. To improve clinical practice and patient outcomes, the endourology community must unite to address these inadequacies.

In 2019, quality improvement has been a central theme throughout leading articles on nephrolithiasis. Real-world outcomes were published on the natural history of stones and residual fragments, patient compliance with medical therapy and treatment-related opioid use. In-depth review of these topics will enhance provider–patient counselling and shape future paradigms in stone disease.

Analyses across all three domains of life are necessary to advance our understanding of taxonomic dysbiosis in human diseases. In the present study, we assessed gut microbiota (eubacteria, archaea, and eukaryotes) of recurrent oxalate kidney stone suffers to explore the extent of trans-domain and functional species dysbiosis inside the gut. Trans-domain taxonomic composition, active oxalate metabolizer and butyrate-producing diversity were explored by utilizing frc-, but-, and buk- functional gene amplicon analysis. Operational taxonomic units (OTUs) level analyses confound with the observation that dysbiosis in gut microbiota is not just limited to eubacteria species, but also to other domains like archaea and eukaryotes. We found that some of healthy eubacterial population retained together with Oxalobacter formigenes and Lactobacillus plantarum colonization in disease condition (p 0.001FDR = 0.05). Interestingly, trans-domain species diversity has been less shared and dysgenic taxa augmentation was found to be higher. Oxalate metabolizing bacterial species (OMBS) and butyrate-producing eubacteria species were found to be decreased in Oxalobacter non-colonizers; and Prevotella and Ruminococcus species which may contribute to oxalate metabolism and butyrate synthesis as well. Our study underscores fact that microbial dysbiosis is not limited to eubacteria only hence suggest the necessity of the trans-domain surveillance in metabolic diseases for intervention studies.

The link between metabolic syndrome (MetS)/obesity and kidney stone disease (KSD) has gained importance over recent years due to the increasing prevalence and healthcare burden worldwide. This review analyses the literature exploring the link between MetS/obesity and KSD and the impact that obesity has on KSD management. Metabolic syndrome has been shown to increase an individual’s risk of developing kidney stone disease, with insulin resistance forming a core component of the pathophysiology. The body habitus of an individual also influences the type of intervention that is most appropriate, with flexible ureteroscopy increasingly being the preferred option in obese patients. It is important for urologists to consider the features of metabolic syndrome to effectively manage episodes of KSD in obese patients. In addition, better quality evidence is required to effectively compare different treatment options in this group of patients.

While ureteroscopy (URS) is a common procedure for ureteric stones, this window between diagnosis and treatment leaves the possibility for a ‘negative’, ‘stoneless’ or ‘diagnostic’ URS. We perform a systematic review to look at the rate of ‘negative ureteroscopy’ and risk factors associated with it. From a total of 3599 articles and 68 abstracts, 4 studies (1336 patients) were selected. The negative URS rate varied from 4 to 14%. Common predictors seem to be female gender, small stones, radiolucent stones and distal ureteric stones. Although infrequent, negative ureteroscopy should be avoided in patients with ureteric stones by performing a low-dose CT scan on the day of surgery. This should especially be performed for females and those with smaller, radiolucent or distal ureteric stones.

Treatment for stone disease has evolved drastically during the past 3-4 decades. Ureteroscopy, percutaneous nephrolithotomy along with SWL, provides the means to treat practically all urinary tract stones with minimal invasion to the patients. However, for complex stone case scenarios where open surgery is being considered, a less invasive and better tolerated option such as laparoscopy (robot assisted or not) can be performed. The present manuscript reviews role of laparoscopic and robotic surgery in treating urinary tract stones.

The goal of this original work was to describe papillary abnormalities using flexible ureteroscopy into a new classification and to assess their relation with stone composition. We performed a prospective monocentric single-operator study aiming to describe various aspects of renal papillae. Data have been prospectively collected during consecutive 164 sequential flexible ureterorenoscopies required for the treatment of renal stones from May 2011 to March 2015. The collected stones have been examined by microscopy and infrared spectrometry. Serum and urine biochemical samples have been systematically analyzed. A total of 74 patients (45.1 %) had renal papillary abnormalities on at least one papilla, excluding typical Randall’s deposits alone. Various abnormalities were reported, some of them being present in the same patient: tip papillary erosions (51.3 %), anchored papillae calculi (47.3 %), subepithelial stones (18.9 %), cryptic papillae (10.8 %), extrophic papillae (9.46 %) and intraductal deposits (2.7 %). Associations between papillary abnormalities and stone types were found. Intraductal deposits were systematically associated with carbonate apatite IVa2 stones and hypocitraturia. A “first step” classification has been established to standardize the description of these papillary abnormalities for future reports and studies. This study highlights the necessity of papillary abnormalities description in further multicentric studies and ureteroscopy’s reports. The established classification needs multicentric evaluation and validation. The endoscopic observation and knowledge of pathological aspects of the papillae should help to better understand pathogenesis of nephrolithiasis. Medical or surgical treatments of some abnormalities should be also discussed and evaluated to improve the prevention of stone recurrence.

The purpose of this study is to assess the knowledge, attitudes, and practice patterns of urologists in Saudi Arabia regarding prevention of recurrent stone formation and how much they follow preventive stone disease management guidelines. A questionnaire about knowledge, attitudes, and practice patterns of urologists in Saudi Arabia regarding prevention of recurrent stone formation was used. The survey comprised three domains: knowledge, attitudes, and practice patterns. Data about gender, duration of experience and health care sector were also collected. Individual responses were recorded, tabulated and compared using descriptive statistics. The overall response rate was 38.8%. All respondents were male urologists. Most of them (62, 71.3%) had an experience of 5-20 years in management of stone disease patients and the majority (74, 85.1%) belonged to the governmental health care sector. A total of 51% of the respondents answered in concordance with the best practice guidelines in at least half of the questions and 40% in all of the questions. Overall, practice patterns of 58% of the respondents were in concordance with the best practice guidelines in all the questions except for the question of practices regarding stone analysis. As regards to attitude domain, a total of 58.7% respondents expressed their agreement or strong agreement with the questions. Urologists' knowledge of stone recurrence preventive programs is suboptimal. They do not apply effectively the best stone prevention practice guidelines in their daily practice as well. Efforts to increase knowledge and enforce its application in daily practice are strongly warranted.

Evaluating and treating renal stone disease in infants are technically challenging. In this study, we evaluated the surgical treatment of renal stones in children under 1 year of age. We retrospectively reviewed the records of patients under 1 year old who were treated with ESWL, endourological or open surgical procedures for renal stone disease between January, 2009 and December, 2012. The patients’ age, gender, stone size, stone location and number, complications, stone-free status, and postoperative complications were recorded. 19 of 121 infants with a mean age of 10.2 ± 3.07 months were treated with surgical procedures. Six (75 %) of eight cystinuria patients required a surgical intervention. Retrograde endoscopic management was performed in thirteen patients (63.4 %) as an initial surgical approach. There were three major (15.7 %) complications. The rate of open surgical procedures was 31.6 % (6 of 19 infants). The cutoff value of stone size for open surgery was 10 mm. There was a significant relationship between the conversion to open procedures and stone size, stone location, and symptom presentation especially the presence of obstruction (p

Introduction Stone analysis is an important part in the evaluation of patients having stone disease. This could orientate the physician toward particular etiologies. Material and methods Chemical and physical methods are both used for analysis. Unfortunately, chemical methods often are inadequate to analyze accurately urinary calculi and could fail to detect some elements into the stone. Physical methods, in counterpart, are becoming more and more used in high-volume laboratories. The present manuscript will provide a review on analytic methods, and review all the information that should be included into an appropriate morpho-constitutional analysis. Conclusion This report can supply an excellent summarization of the stone morphology and give the opportunity to find specific metabolic disorders and different lithogenic process into the same stone. Here, specific chemical types with their different crystalline phases are shown in connection with their different etiologies involved.

Purpose of Review The incidence of urinary stone disease among the paediatric population is increasing. Whilst there has been a rise in the number of original studies published on ureteroscopy (URS) in children, critical review still remains under-reported. Recent Findings A Cochrane style systematic review was performed to identify all original articles on URS (minimum of 25 cases) for stone disease in paediatric patients between Jan. 1996 and Dec. 2016. Based on the number of reported cases, centres were divided into medium (25–49 cases) and high (≥ 50 cases) volume studies. Thirty-four studies (2758 children) satisfied our search criteria and were included in this review. The mean stone size was 8.6 mm with an overall stone-free rate (SFR) of 90.4% (range 58–100). Medium-volume centres reported a mean SFR of 94.1% (range 87.5–100), whilst high-volume centres reported a mean SFR of 88.1% (range 58–98.5). Mean number of sessions to achieve stone-free status in medium-volume and high-volume groups was 1.1 and 1.2 procedures/patient respectively. The overall complication rate was 11.1% (327/2994). Breakdown by Clavien grade was as follows: Clavien I 69% and Clavien II/III 31%. There were no Clavien IV/V complications, and no mortality was recorded across any of the studies. The overall failure to access rate was 2.5% (76/2944). Medium-volume and high-volume studies had overall complication rates of 6.9% (37/530) and 12.1% (287/2222) respectively, but there was no significant difference in major or minor complications between these two groups. Summary Ureteroscopy is a safe and effective treatment for paediatric stone disease. Medium-volume centres can achieve equally high SFRs and safety profiles as high-volume centres. Despite the rarity of paediatric stone disease, our findings might increase the uptake of paediatric URS procedures.

Background The aim of this study was to evaluate the role of flexible cystoscopy in preventing malpositioning of the ureteral stent after laparoscopic ureterolithotomy in male patients. Methods From April 2009 to June 2015, 97 male patients with stones >1.8 cm in the upper ureter underwent intracorporeal double-J stenting of the ureter after laparoscopic ureterolithotomy performed by four different surgeons. In the last 50 patients who underwent laparoscopic ureterolithotomy flexible cystoscopy was performed through the urethral route to confirm the position of the double-J stent, while in the first 47 correct positioning of the stent was confirmed through postoperative KUB. The demographic data and perioperative outcomes were reviewed retrospectively. Penalized logistic regression analysis was used to evaluate the effects of flexible cystoscopy. Results Upward malpositioning of the ureteral stent was found in 9 of the 47 (19.1%) patients who underwent surgery without flexible cystoscopy. Among the 50 most recent patients who underwent surgery with flexible cystoscopy through the urethral route, upward malpositioning was observed in 10 (20%) patients. The factors preventing upward malpositioning of the double-J catheter in multivariate analysis were surgeon (p = 0.039) and use of flexible cystoscopy (p = 0.008). Conclusion Flexible cystoscopy is a simple, safe, quick, and effective method to identify and correct malpositioning of double-J stents, especially in male patients. Trial registration This study was registered with ClinicalTrials.gov Registry on May 11, 2017 (retrospective registration) with a trial registration number of NCT03150446. Electronic supplementary material The online version of this article (doi:10.1186/s12894-017-0232-4) contains supplementary material, which is available to authorized users.

Background Ureteral stenting has been a fundamental part of various urological procedures. Selecting a ureteral stent of optimal length is important for decreasing the incidence of stent migration and complications. The aim of the present study was to develop and internally validate a model for predicting the ureteral length for ureteral stent insertion. Methods This study included a total of 127 patients whose ureters had previously been assessed by both intravenous urography (IVU) and CT scan. The actual ureteral length was determined by direct measurement using a 5-Fr ureteral catheter. Multiple linear regression analysis with backward selection was used to model the relationship between the factors analyzed and actual ureteral length. Bootstrapping was used to internally validate the predictive model. Results Patients all of whom had stone disease included 76 men (59.8%) and 51 women (40.2%), with the median and mean (± SD) ages of 60 and 58.7 (±14.2) years. In these patients, 53 (41.7%) right and 74 (58.3%) left ureters were analyzed. The median and mean (± SD) actual ureteral lengths were 24.0 and 23.3 (±2.0) cm, respectively. Using the bootstrap methods for internal validation, the correlation coefficient (R2) was 0.57 ± 0.07. Conclusion We have developed a predictive model, for the first time, which predicts ureteral length using the following five preoperative characteristics: age, side, sex, IVU measurement, and CT calculation. This predictive model can be used to reliably predict ureteral length based on clinical and radiological factors and may thus be a useful tool to help determining the optimal length of ureteral stent.

Ureteroscopic management of urolithiasis in pregnancy has been on the rise. Technological advancements such as the development of the semi-rigid or flexible ureteroscope, improvements in the design of baskets used for retrieval and the availability of laser have enabled atraumatic fragmentation of stones. We did a systematic review of literature from January 1990 to December 2012. Data were analysed separately for the time period from January 1990 to June 2010 (Period 1) and for last 2.5 years from July 2010 to December 2012 (Period 2). Inclusion criteria were all English language articles with at least three patients reported. Data were extracted on the outcomes and complications reported in the literature. A total of 271 procedures (116 in period 1, 155 in period 2) across 21 studies were reported in the last 22 years. General anaesthesia was used in 38% (44/116) in period 1 and in 64% (99/155) in period 2. The average stone size (7.6 mm) and stone-free rate (SFR) (85%) were similar in both time periods. Fluoroscopy was used in 20% (23/116) and 24% (38/155) in period 1 and 2, respectively. There were fewer complications in period 1 (n = 9) than period 2 (n = 25). These complications were divided into obstetric (n = 5) and non-obstetric complications (n = 29). There were no maternal or foetal deaths during the 22 years. Stone treatment using ureteroscopic techniques in pregnancy can achieve a high success rate. Evidence suggests a rise in the risk of complications with increasing number of these procedures in pregnancy.

To determine the metabolic risk factors in children and adults with urinary system stone disease.Between September 2008 and February 2011, 257 patients who underwent 24-h urine analysis because of urinary system stone disease were included in the present study. Group I and II include only adult patients. The first-time stone formers were named as Group I (n = 106), and recurrent stone formers were named as Group II (n = 107). Group III was occurred by pediatric patients (n = 44). Control group includes 105 people was called as Group IV. This group was divided into two subgroups. Group IVa includes 70 adult people, and Group IVb includes 35 children. The metabolic evaluation results of patients and control groups were compared.Hypercalciuria (35.8, 44.9, and 47.7 % for Group I, II, and III, respectively) and hypocitraturia (42.5, 40.2, and 50 % for Group I, II, and III, respectively) were most common risk factors for stone formation. However, unlike the literature, we have seen that hypomagnesiuria is also an important risk factor in adults and children. Hypomagnesiuria was defined at 36.4 % in Group I, 29 % in Group II, and 56.8 % in Group III (p0.05 for each group). These three parameters were significantly different between patient and control groups.Hypomagnesiuria, hypocitraturia, and hypercalciuria are the most important risk factors for stone formation in adults and pediatric patients.

Oxalobacter formigenes is a unique intestinal organism that relies on oxalate degradation to meet most of its energy and carbon needs. A lack of colonization is a risk factor for calcium oxalate stone disease. Protection against calcium oxalate stone disease appears to be due to the oxalate degradation that occurs in the gut on low calcium diets with a possible further contribution from intestinal oxalate secretion. Much remains to be learned about how the organism establishes and maintains gut colonization and the precise mechanisms by which it modifies stone risk. The sequencing and annotation of the genomes of a Group 1 and a Group 2 strain of O. formigenes should provide the informatic tools required for the identification of the genes and pathways associated with colonization and survival. In this review we have identified genes that may be involved and where appropriate suggested how they may be important in calcium oxalate stone disease. Elaborating the functional roles of these genes should accelerate our understanding of the organism and clarify its role in preventing stone formation.

Objectives: To present our experience in managing encrusted ureteral stents and to review the literature on the subject. Methods: A total of 22 patients with encrusted ureteral stent were treated in our department. Encrustation of the stent and associated stone burden were evaluated using plain radiography, sometimes supplemented by intravenous urography or ultrasonography. The treatment method was determined by the site of encrustation, the size of the stone burden and the availability of endourologic equipment. Results: Stents were inserted for stone disease in 17 patients, for congenital abnormality in 3 and for ureteric obstruction by malignancy in 2. Stents were left in place for a mean of 10.8 months (range 5–34 months). The site of encrustation was in the bladder in 15 (68.2%), ureter in 13 (59%) and kidney in 8 patients (36.4%); more than one site was involved in 11 (50%) cases. For upper coil encrustations, retrograde ureterorenoscopy was performed in 9 cases, percutaneous nephrolithotomy in 4 and open pyelolithotomy in 2. For lower coil encrustation, fragmentation by grasper and/or transurethral cystolithotripsy was attempted in 11 cases, and suprapubic cystolithotomy was required for failure in 7 cases. Sixteen patients (72.7%) were rendered stone-free and 5 (22.7%) had clinically insignificant residual stones (3 mm or less). Conclusions: Encrustation is one of the most difficult complications of ureteral stents and its management is a complex clinical scenario for the treating surgeon. The combination of several surgical techniques is often necessary but the best treatment remains the prevention of this problem by providing patient education.

To determine if calcium deposits in the papillae can be identified by unenhanced computed tomography (uCT) even before renal stones develop. A retrospective review of 413 patients with calculi identified 31 patients (stone-forming group) with a history of urinary tract calculi with a calculus demonstrated by uCT and a stone-free uCT before calculi had developed. The control group (n = 31) was composed of live kidney donors with no history of calculi and a stone-free uCT. CT attenuation was measured in all CTs using two regions of interest of 0.05 cm2 and 0.1 cm2 over the tip and the neighbouring area of the papillae. Student's and Wilcoxon t-tests were used for comparing results in the two groups. The attenuation of the tip of the papilla was higher in the stone-forming group when compared to the controls after (45.2 HU versus 32.1 HU, P = 0.001) and even before frank calculi had developed (44.2 HU versus 32.1 HU, P = 0.003). There was no significant difference in papillary attenuation in the stone group before and after calculi had developed (45.2 HU versus 44.2 HU, P = 0.82). Stone-forming patients exhibit higher papillary density even before calculi develop. This could define a population at risk of developing calculi. • Unenhanced CT shows high density papillae in patients who subsequently develop calculi. • These probably correlate with Randall’s plaques. • Subjects at high risk of developing stone disease could be identified. • Targeted prophylaxis might be helpful.

We aimed to review a current management of paediatric nephrolithiasis. The current literature, including our own experience on the treatment of paediatric nephrolithiasis was reviewed by MEDLINE/PubMed search. We have used in our search following keywords: urolithiasis, nephrolithiasis, paediatrics, surgical treatment, conservative management, ESWL, ureteroscopy, and open renal surgery. The search was limited to the English language literature during the period of time from 1990 to 2011. All papers were reviewed independently by all co-authors and only the manuscripts directly related to the reviewed subjects were included into the current review. Due to the high incidence of predisposing factors for urolithiasis in children and high stone recurrence rates, every child with urinary stone should be given a complete metabolic evaluation. Most stones in children can be managed by ESWL and endoscopic techniques. Paediatric stone disease is an important clinical problem in paediatric urology practice. Because of its recurrent nature, every effort should be made to discover the underlying metabolic abnormality so that it can be treated appropriately. Obtaining a stone-free state with interventional management and close follow-up are of utmost importance.

Cystinuria is a relatively uncommon cause of pediatric stone disease, but has significant morbidity if not properly controlled because of its significant stone recurrence rate. Cystinuria is caused by the inability of the renal tubules to reabsorb filtered cystine, which is poorly soluble at a typical urine pH

Infection and stones can be associated in two ways. Stone disease can occur due to infection by an organism that expresses the urea-splitting enzyme urease (infection stones). Nephrolithiasis can also be complicated by urinary tract infection that in turn was caused by obstruction of the urinary tract by a stone and/or colonization of a pre-existing stone, in both cases by non-urease producing organisms. Although the incidence of infection stones appears to have declined over recent years in the United States, they remain a cause of significant morbidity and mortality. A strong index of suspicion is necessary to identify infection stones before they become large, damage kidneys, or lead to acute morbidity such as urosepsis. Surgery remains the mainstay of therapy for infection stones, combined with careful attention to antibiotic choice based upon appropriate culture results. Use of medical therapy alone is reserved for those relatively unusual cases in which there is a strong contraindication to surgery. Infection-related stones also require prompt recognition, often via use of non-contrast CT. Any obstruction that is present needs to be promptly relieved in order to decompress the kidney and allow the infection to be cleared by antibiotics chosen based upon culture results.

International audience; Although the 36-Item Short-Form General Health Survey (SF-36) has been utilized to assess quality of life (QoL) in cross-sectional studies, no longitudinal studies have evaluated this instrument in stone formers. Hence, we evaluated the performance of the SF-36 over time in a group of stone formers. From January to May 2007, the SF-36 was administered by independent interviewers to 155 patients with a history of stones, and 96 individuals subsequently completed a second questionnaire at a median interval of 18 months (10.3-28.5 months). Subjects were asked to report changes in stone status, interval procedures, and significant non-stone related changes. Changes in individual and composite scores of SF-36 were compared. Among the 96 patients who completed two SF-36 surveys, 75 patients denied experiencing a stone episode within the month preceding their initial or follow-up SF-36 form. No statistically significant differences in any of the SF-36 domains or the aggregate physical or mental health composite scores over time were noted in these patients. A total of 18 patients reported a stone event within the month preceding completion of the initial questionnaire but no stone event prior to the follow-up survey. No clinically or statistically significant changes in any of the SF-36 domains between the first and follow-up questionnaire were seen among these 18 patients. The results show the stability of the SF-36 over time in patients with no change in their stone status. However, the absence of significant changes in the SF-36 despite a change in stone status suggests that the SF-36 may not be an adequate tool to monitor quality of life over time in stone patients. Validated, disease-specific questionnaires are needed to facilitate comparison of treatment strategies for stone disease.

The goal in the treatment of stone disease causing infantile obstructive uropathy is to obtain a quick resolution of the obstruction using the least invasive treatment modality available and rendering the patient stone-free, if possible. Two infants with bilateral kidney stones, the first of whom also had ureteral stone, were referred to our clinic with acute renal failure and were treated successfully in a single session using minimally invasive methods. In this report, we discuss the management of these two cases, aged 9 and 26 months, which resulted in favorable outcomes.

Data concerning nine forms of human stone disease, along with observations on normal people give new insights into formation of interstitial apatite plaque and intra-tubular crystal deposits. In general, across multiple disease states, one can reproduce the same relationships between plaque abundance as is seen among patients within individual disease states, so that the link between plaque and high urine calcium excretion, and low urine volume and pH seems increasingly secure. From this, one can propose a specific model of plaque formation, susceptible to experimental test. In many diseases, formation of inner medullary collecting duct and Bellini duct deposits is compatible with simple crystallization driven by urine supersaturations; this is expected in that these segments contain tubule fluid quite close in composition to final urine. But in ileostomy, small bowel disease and obesity bypass patients, crystals found in deposits are not those expected: apatite and urates in deposits, despite formation of highly acidic urine. Also, this discrepancy suggests the possibility of divergence between bulk urine pH and pH of focal collecting ducts, a new kind of possibility that is susceptible to experimental test.

Paediatric nephrolithiasis is quite challenging in terms of management because of the smaller size of the urinary tract and the bigger risk for stone recurrence. Children bear a higher risk of metabolic and infectious causes of stone disease and a longer lifetime risk for recurrence, especially in cases of residual fragments. Complete stone clearance should become the absolute objective and clinically insignificant residual fragments should be avoided. Nowadays, percutaneous nephrolithotomy (PCNL) arises as a logical first-line treatment option for considerable paediatric nephrolithiasis as miniaturization of endoscopes and advances in energy sources for stone fragmentation have facilitated stone-free rates. In this review we present the evolution of PCNL in children and we demonstrate its safety and efficacy. As appropriate instruments are available and relevant surgical experience is accumulating, age should no longer exist as a limiting factor for performing PCNL.

The prevention or cure of stone disease will be achieved only by identifying biochemical, physiological and molecular mechanisms operating before the formation of a calculus. Yet, the gradual increase in the total number of papers devoted to the study of kidney stones that has occurred since the beginning of the 21st century can be attributed almost entirely to papers concerned with the investigation of factors associated with urolithiasis after stones have already formed. The need to prevent stones by discovering how the human body routinely stops their formation in those of us who do not suffer from them is therefore as exigent as ever and a new approach to investigating the causes of stones is urgently needed. In this paper, I develop the view that stone research will best progress by examining and understanding how healthy plants and animals control the formation of biominerals. In addition to structures like bones, teeth, shells and spines, many organisms spanning the entire phylogenetic tree form intra- and extracellular granules which are use as storage depots for calcium and other important ions, which they can reclaim to maintain homeostasis or to satisfy specific needs during periods of high demand, such as shell formation, moulting or skeletal development. These electron-dense granules, which also bear an uncanny resemblance to calcified nanobacteria, are remarkably similar in general structure, size and composition to particles observed in healthy human kidneys and in Randall's plaque. Therefore, it is likely that the granules in human kidneys fulfil analogous functions to those in other organisms-particularly in calcium homeostasis. Their study in a large range of creatures has already provided a deep well of information about their structure, movement, composition, macromolecular content, synthesis and resorption, from which we can draw to quench our thirst for knowledge of basic mechanisms and events involved in the formation of human kidney stones.

Obesity represents an increasing burden to health care resources. Nephrolithiasis is associated with obesity and type 2 diabetes and the consumption of diets rich in protein, fat and carbohydrates; this article addresses some of the pathophysiological mechanisms associated with stone formation in these patients. Management of stone disease can be more difficult in obese patients; even diagnosis can be problematic because imaging techniques are less sensitive in these patients. Treatment with extracorporeal shockwave lithotripsy and surgery in obese patients can be challenging, and outcome data for the different treatments are discussed in this Review.

The aim of the study was to investigate the diagnostic value of the colour Doppler twinkling artefact (TA) in renal stone disease. To enhance the evidence of TA, a preliminary in vitro study was performed to optimise the setting of colour Doppler sonography. In the in vitro study, an oxen kidney was examined using an high-frequency (12.5 MHz) linear array probe in a water bath before and after the inoculation of an aliquot of powder obtained by fragmentation of a calcium oxalate stone. In the clinical study, 67 patients with diagnosis of urinary stone based on B-mode sonography and 67 matched control subjects were examined with colour Doppler sonography using a low-frequency (2.5 MHz) curvilinear phased array probe. In vitro, the injection of calcium oxalate powder in a bovine kidney sample induced the appearance of spots without any back shadowing appearance on B mode but with a large number of TA on colour Doppler. In vivo, TA was much more frequent in patients with stone disease (95.5%) compared to controls (9.0%) (P < 0.001). TA was highly associated to renal stone disease and was also present in renal areas where a stone was undetected with B mode approach suggesting its diagnostic role although further studies are needed to confirm its accuracy. The type of instrumentation and its setting is crucial to obtain reproducible results.

Though the most common use for lasers in the genitourinary tract is for urolithiasis, a number of other urologic conditions can be treated with lasers because of their unique ablative, destructive and hemostatic properties. This paper reviews the advantages and disadvantages of laser technology for a number of non-stone indications.

Renal stone disease is becoming increasingly prevalent globally. With a rise in stone disease worldwide, there is also a relative increase in the rates of surgical intervention. Technological advances have allowed a move towards minimising the complications rates and length of stay with a reduction in invasiveness and size of instruments. A trend for minimising the percutaneous tract size has been noted in percutaneous nephrolithotomy (PCNL) for renal stones. The management has shifted from open surgery to standard PCNL, mini-PCNL and the latest ultra-mini and micro-PCNL techniques. There is a need to compare outcomes for the ever-advancing technologies, such as the smaller calibre of instruments, to assess risk-benefit in practice. This review looks at outcome-based comparison of percutaneous procedures for urinary lithiasis with instruments

Patients receive significant radiation exposure during the diagnosis, treatment, and follow-up of urinary stone disease. This radiation exposure may result in patient harm and is believed to contribute to the risk for malignancy. This review will present current information to allow surgeons to optimize their diagnostic, treatment, and follow-up regimens to allow optimal care of stone disease patients at the lowest radiation dose possible.