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In the process of urinary stone formation, several heavy metals and trace elements (HMTE) have been identified among the major constituents of the calculi. The micro-elements within the stones cannot be identified by ordinary laboratory analytical techniques, the latter can only detect the major crystalline component. The objective of the present study was to evaluate the different types of HMTE (no. 22) and their concentrations within the urinary stones. The stone samples were obtained from patients living in different geographical locations (10 countries: 5 Western and 5 non-Western). The number of retrieved stones after open or endoscopic procedures was 1177. The concentrations of the 22 HMTE in the stones were assessed by inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical data were analyzed using Kruskal-Wallis, one-way ANOVA, and SPSS software (version 20). The biochemical stone analysis showed that calcium oxalate was present as a major component in 650 patients (55.2%), calcium phosphate in 317 (26.9%), and uric acid and cystine stones in 210 (17.8%). The analyzed stones showed the presence of HMTE in different concentrations. Significantly higher concentrations of 17 elements (Al, As, Ba, B, Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, S, Se, Sr, and Zn) were noted in all stones. Seven elements (Al, As, Se, Sr, Fe, Zn, and Ni) were present in higher concentrations in calcium-based stones. In comparison, eight elements (Mg, B, Ba, Cd, Se, Pb, Sr, and Zn) in higher concentrations were associated with phosphate-based stones. Both uric acid and cystine stones had a higher concentration of sulfur. The concentrations of HMTE in calcium phosphate stones were higher than in calcium oxalate and uric acid stones. Calculi obtained from patients living in western countries contained higher levels of 13 HMTE (B, Ba, Ca, Cd, Co, Cu, Fe, K, Mg, Mo, P, Pb, and Se) than those in non-western countries. The age of calculi-forming patients from non-western countries was younger than those living in western countries. These results may indicate the role of many significant heavy metals and trace elements in the pathogenesis of urinary stone formation. The types and contents of HMTE within urinary stones differ from one country to another. The conventional stone analysis techniques cannot either identify the stone micro-elements or the concentrations of HMTE, so a specific and additional instrument such as the ICP-OES is necessary. Further research work on the urinary stone micro-elemental structure could lead to a new strategy for the prevention of stone formation and recurrence., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To systematically assess the quality of videos on the surgical treatment of urinary stones available on YouTube using validated instruments., Methods: A systematic search for videos on YouTube addressing treatment options of urinary stones was performed in October 2019. Assessed parameters included basic data (e.g. number of views), the grade of misinformation reporting of conflicts of interest. Quality of content was analyzed using the validated DISCERN questionnaire. Data were analyzed using descriptive statistics., Results: A total of 100 videos with a median of 26,234 views (1020-1,720,521) were included in the analysis. Of these, only 26 videos were rated to contain no misinformation and only nine disclosed potential conflicts of interest. Overall, the median quality of the videos was low (2 out of 5 points for DISCERN question 16). Videos uploaded by healthcare professionals and medical societies/organizations offered significantly higher levels of quality. In particular, the videos provided by the EAU achieved the highest rating with a median score of 3.0., Conclusions: The majority of videos concerning the surgical treatment of urinary stones have a low quality of content, are potentially subject to commercial bias and do not report on conflicts of interest. Videos provided by medical societies, such as the EAU, provide a higher level of quality. This highlights the importance of active recommendation of evidence-based patient education materials.

Non-contrast enhanced computed tomography (NCCT) is widely used measuring stone size in patients with urolithiasis. We performed an evaluation of the accuracy of stone size measuring via NCCT. In an in-vitro study, we analyzed a total of 38 uric acid and 38 phantom stones. Within NCCT, we used different slice thicknesses (1.5 mm, 2.0 mm, and 3.0 mm) and kernel settings (bone and soft-tissue window). Maximal height, maximal length, and maximal width of each stone were measured on a picture archiving and communication system workstation. Blinded to these results, a second physician measured stone size in the same way using a caliper (real stone size). We used the Bland-Altman method for the analysis of agreement between the two measuring methods. The limit of agreement that was deemed clinical insignificant was ± 1.0 mm. All measurements via NCCT correlated significantly with the real stone size (p < 0.001). This was more pronounced for bone window and smaller slice thickness. Bland-Altman plots showed limits of agreement that exceeded the a priori defined level for all types of measurement with bone window and small slice thickness (1.5 mm) being better than soft-tissue window and large slice thickness (3.0 mm). We conclude that stone size measurement by NCCT with established settings is not exact. Stone size can easily be over- or underestimated by several millimeters. Using bone window and small slice thickness leads to more accurate results.

Introduction: Urologists have to master a variety of techniques to be able to offer the most appropriate surgical stone treatment for each individual patient. Therefore, we performed a survey among board-certified Swiss urologists to assess the availability of the different surgical methods, the current practices of surgical treatment of urolithiasis and the adherence to evidence-based guideline recommendations in Switzerland., Methods: A 14-question survey assessed the working environment, equipment, perioperative settings and decision trees for specific stone scenarios. Data was analyzed using descriptive statistics and chi-square tests to determine differences between frequencies of answers., Results: Hundred and five members of Swiss Urology (38%) completed the survey. All treatment modalities are available for the majority of respondents. Ureterorenoscopy was found to have the highest availability (100%) and was the preferred choice in the majority of stone scenarios. A high adherence to the guidelines was found for the treatment of ureteral stones <10 mm (100% proximal and distal), and >10 mm (69% proximal, 94% distal). All respondents answered in accordance with the guidelines regarding the treatment of middle and upper pole stones <10 mm, 10-20 mm and lower pole stones 10-20 mm. Guideline adherence was 99% for lower pole stones <10 mm, 78% for lower pole stones >20 mm, and 63% for middle/upper pole stones >20 mm., Conclusion: This survey provides a detailed insight into current stone treatment practices in Switzerland. The full spectrum of urinary stone treatment options is available for the majority of Swiss urologists. The choice of treatment shows a high accordance with evidence-based guidelines and a preference for retrograde endoscopic surgery in the majority of stone scenarios., (© 2019 S. Karger AG, Basel.)

After stone removal, accurate analysis of urinary stone composition is the most crucial laboratory diagnostic procedure for the treatment and recurrence prevention in the stone-forming patient. The most common techniques for routine analysis of stones are infrared spectroscopy, X-ray diffraction and chemical analysis. The aim of the present study was to assess the quality of urinary stone analysis of laboratories in Europe. Nine laboratories from eight European countries participated in six quality control surveys for urinary calculi analyses of the Reference Institute for Bioanalytics, Bonn, Germany, between 2010 and 2014. Each participant received the same blinded test samples for stone analysis. A total of 24 samples, comprising pure substances and mixtures of two or three components, were analysed. The evaluation of the quality of the laboratory in the present study was based on the attainment of 75% of the maximum total points, i.e. 99 points. The methods of stone analysis used were infrared spectroscopy (n = 7), chemical analysis (n = 1) and X-ray diffraction (n = 1). In the present study only 56% of the laboratories, four using infrared spectroscopy and one using X-ray diffraction, fulfilled the quality requirements. According to the current standard, chemical analysis is considered to be insufficient for stone analysis, whereas infrared spectroscopy or X-ray diffraction is mandatory. However, the poor results of infrared spectroscopy highlight the importance of equipment, reference spectra and qualification of the staff for an accurate analysis of stone composition. Regular quality control is essential in carrying out routine stone analysis.

Context: An optimum metabolic evaluation strategy for urinary stone patients has not been clearly defined., Objective: To evaluate the optimum strategy for metabolic stone evaluation and management to prevent recurrent urinary stones., Evidence Acquisition: Several databases were searched to identify studies on the metabolic evaluation and prevention of stone recurrence in urolithiasis patients. Special interest was given to the level of evidence in the existing literature., Evidence Synthesis: Reliable stone analysis and basic metabolic evaluation are highly recommended in all patients after stone passage (grade A). Every patient should be assigned to a low- or high-risk group for stone formation. It is highly recommended that low-risk stone formers follow general fluid and nutritional intake guidelines, as well as lifestyle-related preventative measures to reduce stone recurrences (grade A). High-risk stone formers should undergo specific metabolic evaluation with 24-h urine collection (grade A). More specifically, there is strong evidence to recommend pharmacological treatment of calcium oxalate stones in patients with specific abnormalities in urine composition (grades A and B). Treatment of calcium phosphate stones using thiazides is only highly recommended when hypercalciuria is present (grade A). In the presence of renal tubular acidosis (RTA), potassium citrate and/or thiazide are highly recommended based on the relative urinary risk factor (grade A or B). Recommendations for therapeutic measures for the remaining stone types are based on low evidence (grade C or B following panel consensus). Diagnostic and therapeutic algorithms are presented for all stone types based on the best level of existing evidence., Conclusion: Metabolic stone evaluation is highly recommended to prevent stone recurrences., Patient Summary: In this report, we looked at how patients with urolithiasis should be evaluated and treated in order to prevent new stone formation. Stone type determination and specific blood and urine analysis are needed to guide patient treatment., (Copyright © 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Background and Purpose: Today, the holmium:YAG laser is the gold standard in endourologic stone treatment because of its high efficacy. However, guidewires and stone-extraction tools often are close to the fiber and may be damaged accidentally by the laser. The aim of our study was to evaluate the duration of laser application required to disrupt wires at different energy settings., Materials and Methods: Two standard wires (0.035-inch guidewire and 0.025-inch hydrophilic Terumo wire) and two baskets (1.9F Nitinol tipless and 3F stone extraction) were investigated. We used a holmium:YAG laser (Auriga; Wavelight Laser Technologie AG, Erlangen, Germany) and two fibers (230 and 365 microm) at 800 and 2000 mJ and a 5-Hz pulse rate. The laser was brought into direct contact with the wires., Results: The average time required for transection was 55 to 103 seconds for a safety wire. The Terumo wire broke after 20 to 40 seconds of direct laser application; 15 to 34 seconds was required for a Dormia basket. Thin Nitinol basket wires were disrupted after only 1 to 4 seconds. One- and two-factorial variance analysis showed a high degree of significance (P < 0.0001) of the energy level and type of wire., Conclusion: The disruption of stone-extraction tools occurs in a remarkably short time with laser exposure, especially in case of Nitinol baskets, whereas guidewires are more resistant. Attention should be paid to avoiding contact of laser energy with wires and baskets during stone fragmentation.

Objectives: After SWL treatment, many patients have residual fragments in the kidney or ureter. Fragments 2 stones episodes. These patients and their referring urologist received follow-up questionnaires which contained questions about stone clearance, late complications, auxillary measures and dietary or drug metaphylaxis., Results: Most residual stone fragments were located within the lower calyx (17%) and the renal pyelon (14%). Stone analysis was available in 142 patients with CIRF and revealed calciumoxalate calculi in 93.6% of the cases. In 78.6%, CIRF cleared spontaneously within few weeks and did not recur within 5 years. However, residual stones led to stone recurrence and need of re-treatment in 21.4%. Renal pyelon (23%) and calices showed comparable growth of former CIRF (lower calices 26.5%, middle calices 27%, upper calices 26%). Only 48% of the patients with recurrent stone formation followed dietary metaphylaxis. However, a significant correlation between a general or specific metaphylaxis and stone growth of CIRF could not be demonstrated., Conclusions: Most of the CIRF after SWL pass spontaneously without any complications. But considering that one fifth of the patients developed new stones at the side of residual fragments, it is obvious that close follow-up is required. Although we could not demonstrate a relation between metaphylaxis and stone re-growth, it is conceivable that adequate metaphylaxis can reduce stone recurrences.

Background and Purpose: The architecture of the lower renal pole seems to have a considerable influence on caliceal stone clearance after different therapeutic modalities. The published data are partially inconsistent, and publications on reproducibility are completely lacking. The aim of this study was to evaluate the intraobserver and interobserver reproducibility of different measures of lower-calix anatomy., Materials and Methods: We studied the intraobserver and interobserver reproducibility of parameters describing the lower-pole anatomy that are significant for treatment outcome. Forty renal units without urologic disease were analyzed by five independent urologists. Infundibular length (IL), infundibular width (IW), and lower infundibulopelvic angles (LIP) were measured by the Elbahnasy (LIP I), Keeley (LIP II), and Gupta (LIP III and LIP IV) methods. Statistical analysis of each parameter and investigator was performed., Results: All LIP angles showed low interobserver correspondence: correlation coefficients (CC) did not exceed 0.44 (P < 0.05). Even the relatively clearly defined parameters IW and IL achieved CCs of only 0.63 and 0.49, respectively. The intraobserver correlation achieved better results: 0.73 (LIP I), 0.84 (LIP II), 0.73 (LIP III), 0.65 (LIP IV), 0.88 (IL), and 0.82 (IW). With the Elbahnasy method, almost all renal units were classified as favorable for stone persistence after shockwave lithotripsy. With the Keeley and Gupta methods, more than 50% of the kidneys were defined as having low clearance probability., Conclusions: Assessment of the chosen parameters is difficult and shows high interobserver variation. Inexperience in measuring the specific angles and low imaging quality can limit correct evaluation. The large number of kidneys with anatomy inappropriate for clearance of lower-pole stones may explain the poor outcome of shockwave treatment for stones in a lower calix. Prospective studies will determine the clinical value of anatomic assessments.

Treatment of renal stones using flexible ureteroscopy (fURS) is increasingly common despite the poor evidence in literature supporting its use and indications. With this study, we wanted to investigate the current use and indication of fURS for the treatment of renal stones in the clinical practice across the European countries. A survey was conducted using an emailed questionnaire consisting of 21 items; 2,894 recipients were selected via the EAU membership database. The questionnaires were collected through the SurveyMonkey system and the data were processed with the SPSS statistical package. Frequencies, cross tabs and Pearson correlation coefficients were applied as appropriate. 1,168 questionnaires were collected (response rate 40.4 %). fURS was performed in 72.9 % of the respondents' institutions, and 54.2 % of the respondents were performing the procedure. For 95 % of the users, fURS was considered first-line treatment, for stone of lower pole stone (45.9 %) and <1 cm (44.2 %) and 2 cm (43.8 %) in size. The ureteral access sheaths were used routinely by more than 70 % of the respondents. Lower pole stone repositioning technique was routinely performed by 45.9 % of the surgeons. After fragmentation, 47.2 % of the responders preferred to retrieve only the bigger fragments. At the end of fURS, lower volume surgeons were more likely to place routinely a double-J stent ( p = 0.001). Higher volume surgeons estimated a higher durability of devices, both optical and digital ones ( p < 0.001), and were more prone to consider fURS cost-effective when compared to other treatment modalities ( p < 0.001). fURS is widely used for the treatment of renal stones and its use and indication can vary according to the age and surgeons' case volume. Higher volume surgeons are more prompt to extend international guidelines indications and to consider the technology cost-effective. [ABSTRACT FROM AUTHOR]

Introduction: The pathogenesis of calcium oxalate stone formation is not completely understood. Recently, an influence of vascular phenomena like arteriosclerosis on the crystallization process was hypothesized. Thus, stone formation should be more common in patients with diabetes mellitus (DM) who are at risk of developing angiopathy. The aim of the study was to determine the prevalence of urolithiasis (UL) in patients with DM and to identify specific risk factors. Material and Methods: 350 patients with DM were evaluated with respect to DM-related history, and a total of 179 patients was included (83 female, 96 male; age 23–84 years). All patients were interviewed to assess the history of stone formation. These data were compared to epidemiological data in Germany. Results: The overall prevalence of UL in the diabetic group was 7.82% (vs. 4.73% in Germany, p = 0.0485; binominal test). The prevalence was significantly higher in patients with coronary heart disease (25%; p < 0.0001; Fisher‘s exact test). We could not demonstrate an increased prevalence of UL for patients with occlusive arterial disease or arterial hypertension as diabetic nephropathy was not a risk factor for developing urinary lithiasis (p = 0.7184, p = 1.000, p = 0.6266, respectively; Fisher’s exact test). Thiazide medication lowered the prevalence of stone formation (p = 0.0399; Fisher’s test). Calcium or magnesium supplementation did not influence stone formation significantly (p = 0.5279; p = 1.000; respectively; Fisher’s test). Conclusions: In Germany, patients with DM are at higher risk of UL compared with patients without diabetes. We demonstrated a significantly higher prevalence of urinary stones in patients with coronary heart disease. These findings are consistent with the hypothesis that urinary stone formation has a vascular pathogenesis in part. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

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The new guidelines of the European (EAU), American (AUA), German, and Austrian associations of urology are based on thorough and consistent research and analysis of the published literature. However, the methodology is very diverse. In the case of the EAU-AUA guidelines on ureteral stones, the evidence was generated by a laborious meta-analysis of the entire available published literature on the subject. These guidelines represent the 1A level of evidence. The traditional European guidelines evaluate each statement separately and assign a level of evidence to each. The following aspects are new: the even greater effort to formulate guidelines accompanied by the initiation of international cooperative projects, clarity of presentation and evaluation of the individual statements (including levels of evidence), information on medication-based treatment to facilitate spontaneous passage of ureteral stones as well as stone fragments after extracorporeal shock wave lithotripsy (ESWL), a shift in the value of ESWL and ureterorenoscopy for ureteral stones, retrograde intrarenal surgery for small kidney stones refractory to ESWL or in settings unsuitable for ESWL, the use of laparoscopy in those rare cases that represent an indication for open surgery, and the additional value given to metaphylaxis in diagnosis and therapy. All of the new guidelines take these developments into account, although they differ slightly in the importance they assign to the individual items. The modifications represent the developments secondary to electronic data processing and preparation on the one hand and the rapid development of medical instruments on the other. Although ESWL is still the most important procedure for treating urinary stones, advances in flexible endoscopes, intracorporeal lithotripsy, and extraction instruments have led to a shift in the range of indications. These developments are fully accommodated in the new guidelines. [ABSTRACT FROM AUTHOR]

We performed a prospective, non-randomised study to determine the appropriate first-line treatment modality for distal ureteral stones. Between 2003 and 2004, a total of 124 patients with distal ureteral calculi were entered into the study (mean age 48 years, 35 women and 99 men). Sixty-two patients were treated with shock wave lithotripsy (SWL) and 62 patients with ureteroscopy (URS). The average stone size was 6.9 mm (3–33 mm) for SWL and 7.2 mm (3–30 mm) for URS. The treatment decision depended on the patients’ preference and clinical parameters (i.e. contraindications for anaesthesia). URS was performed under general anaesthesia, using semirigid 8 Fr instruments. SWL was performed under analgo-sedation using a Modulith SLX. Of patients treated with SWL, 84% had a treatment success within 7 days, 98% after URS. These results show a significant success ( P=0.005) in favour of URS. The average in-patient stay after SWL was 3 days and for URS 4 days (not significant). The results show a high efficacy and a low complication rate for both modalities. The attained stone-free rate shows a significant advantage for primary URS. [ABSTRACT FROM AUTHOR]