Preliminary assessment of a portable Raman spectroscopy system for post-operative urinary stone analysis.

PURPOSE: We aimed to evaluate the reliability of a portable device that applies Raman spectroscopy at an excitation wavelength of 1064 nm for the post-operative analysis of urinary stone composition. MATERIALS AND METHODS: Urinary stone samples were obtained post-operatively from 300 patients. All samples were analyzed by the portable Raman spectroscopy system at an excitation wavelength of 1064 nm as well as by infrared spectroscopy (IR), and the results were compared. RESULTS: Both Raman spectroscopy and IR could detect multiple stone components, including calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, uric acid, cystine, and magnesium ammonium phosphate hexahydrate. The results from 1064-nm Raman analysis matched those from IR analysis for 96.0% (288/300) of cases. Although IR detected multiple components within samples more often than Raman analysis (239 vs 131), the Raman analysis required less time to complete than IR data acquisition (5 min vs 30 min). CONCLUSIONS: These preliminary results indicate that 1064-nm Raman spectroscopy can be applied in a portable and automated analytical system for rapid detection of urinary stone composition in the post-operative clinical setting. TRIAL REGISTRATION: Chinese Clinical Trail Register ID: ChiCTR2000039810 (approved WHO primary register) http://www.chictr.org.cn/showproj.aspx?proj=63662 .

A quick stone component analysis matters in postoperative fever: a propensity score matching study of 1493 retrograde intrarenal surgery.

OBJECTIVE: To evaluate the role of stone components in postoperative fever following RIRS, and to investigate the role of quick stone component analysis during RIRS procedure. PATIENTS AND METHODS: 1493 patients with RIRS were retrospectively reviewed. Propensity score matching (PSM) analysis was performed as infection stones (IS) vs. calcium-containing stones (CS) and IS vs. other compositions (OS). Independent risk factors of postoperative fever were identified by logistic analysis and nomogram was constructed. RESULTS: A total of 73 patients suffered postoperative fever (4.9%), 8 patients with sepsis (0.5%), 4 patients with septic shock (0.3%). In IS vs. CS, the incidence of positive urine test (28.4% vs. 14.7%, p = 0.001), residual stone (48.2% vs. 37.6%, p = 0.04), and postoperative fever (9.1% vs. 2.0%, p = 0.004) was significantly higher in IS. In IS vs. OS, IS had a higher incidence of positive urine test (30.9% vs. 9.3%, p < 0.001) and residual stone (47.4% vs. 18.6%, p < 0.001), while there was no significant difference in postoperative fever (10.3% vs. 4.1%, p = 0.17). Multivariate regression analysis revealed that gender (OR 1.82, CI 1.09-3.07, p < 0.001), stone components (OR 0.6, CI 0.37-0.97, p = 0.038), urine test (OR 3.72, CI 2.23-6.20, p < 0.001), and neutrophil ratio > 75% (OR 5.17, CI 3.03-9.16, p < 0.001) were independent risk factors for postoperative fever. A nomogram with moderate discriminative ability (c-index: 0.813) was constructed to predict postoperative fever. CONCLUSION: Infection stones were closely associated with postoperative fever following RIRS, as well as female gender, preoperative positive urine test, and postoperative neutrophil ratio > 75%. A quick stone component analysis would help in prevention of infectious complications. Early and longer duration of antimicrobial therapy was recommended for patients with infection stones.

Using micro computed tomographic imaging for analyzing kidney stones.

Stone analysis is a critical part of the clinical characterization of urolithiasis. This article reviews the strengths and limitations of micro CT in the analysis of stones. Using micro CT alone in a series of 757 stone specimens, micro CT identified the 458 majority calcium oxalate specimens with a sensitivity of 99.6% and specificity of 95.3%. Micro CT alone was also successful in identifying majority apatite, brushite, uric acid, and struvite stones. For some minor minerals-such as apatite in calcium oxalate or calcium salts in uric acid stones-micro CT enables the detection of minute quantities well below 1%. The addition of a standard for calibrating X-ray attenuation values improves the ability of micro CT to identify common stone minerals. The three-dimensional nature of micro CT also allows for the visualization of surface features in stones, which is valuable for the study of stone formation.

Revised classification of the righteye flounders (Teleostei: Pleuronectidae) based on multilocus phylogeny with complete taxon sampling.

Members of the family Pleuronectidae are common representatives of the marine benthic fauna inhabiting northern regions of the Atlantic and Pacific oceans. The most recent comprehensive classification of the family, based entirely on morphological synapomorphies, recognized five subfamilies, 23 genera, and 61 extant species. However, several subsequent molecular studies have shown that many synapomorphic characters discovered in the morphological study might represent homoplasies, thereby questioning the reliance on these characters with the warning that they may provide misleading information for testing other morphology-based evolutionary hypotheses. In the present study, we propose a comprehensive taxonomic reassessment of the family Pleuronectidae based on the molecular phylogeny reconstructed from four nuclear and three mitochondrial loci and represented by complete taxon sampling of all but one valid species currently assigned to this family. To check for robustness of the phylogenetic hypothesis, we analyzed the effect of base compositional heterogeneity on phylogenetic signal for each locus and compared six different gene partitioning schemes. The final dataset, comprising 14 partitions and 154 individuals, was used to reconstruct phylogenetic trees in RAxML, MrBayes and BEAST2. Alternative topologies for several questionable nodes were compared using Bayes factors. The topology with the highest marginal likelihood was selected as the final phylogenetic tree for inferring pleuronectid relationships and character evolution. Based on our results, we recognize the Pleuronectidae comprising five subfamilies, 24 genera and 59 species. Our new phylogeny comprises five major monophyletic groups within the family, which we define as the subfamilies within the family: Atheresthinae, Pleuronichthyinae, Microstominae, Hippoglossinae and Pleuronectinae. Taxonomic composition of most of these subfamilies is different from that proposed in previous classifications. We also re-assess hypotheses proposed in earlier studies regarding intra-relationships of species of each lineage. Results of the current study contribute to better understanding of the evolutionary relationships of pleuronectid flatfishes based on molecular evidence, and they also provide the framework towards future comprehensive morphological revision of constituent lineages within the family Pleuronectidae.

Chronological Trends in Clinical and Urinary Metabolic Features over 20 Years in Korean Urolithiasis Patients.

Urolithiasis is common and is becoming more prevalent worldwide. This study assessed the chronological trends in clinical and urinary metabolic features over 20 years in Korean urolithiasis patients. We performed a retrospective analysis of 4,076 patients treated at our clinic from 1996 to 2015. Urinary metabolic data and stone analysis data were available for 1,421 and 723 patients (34.9% and 17.7%), respectively. Patients were categorized into 4 groups according to the date of initial diagnosis: group 1 (1996-2000, n = 897), group 2 (2001-2005, n = 1,018), group 3 (2006-2010, n = 1,043), and group 4 (2011-2015, n = 1,118). Incidental detection of uric acid renal stones has become more prevalent in the past 10 years, accompanied by an increase in body mass index and age at diagnosis. Similarly, the prevalence of diabetes mellitus and of hypertension increased from one group to the next throughout the study period. Levels of 24-hour urinary excretion of sodium, calcium, uric acid, and oxalate have decreased significantly over the study period. The incidence of urinary metabolic abnormalities also showed an identical tendency. The proportion of stones composed of uric acid increased over the study period. In conclusion, incidental detection of uric acid renal stones has become more prevalent in Korea in the past 20 years. Urinary excretion of lithogenic constituents and the incidence of urinary metabolic abnormalities have decreased significantly over this period.

[Mineralogical composition of urinary stones, risk factors and metabolic disturbances in patients with calcium-oxalate urolithiasis].

AIM: To identify the most likely metabolic disturbances and risk factors for stone formation in a group of patients with calcium oxalate urolithiasis, and to establish the relationship between the mineralogical composition of calculi and impaired excretion of inhibitors and promoters of stone formation. MATERIALS AND METHODS: Fifty patients with calcium oxalate urolithiasis were tested using a complex of physicochemical methods. Patients assessment included evaluation of quantitative mineralogical composition of calculi, daily urine pH profile and daily urinary excretion of urates, calcium, magnesium, oxalate, phosphate and citrate ions. RESULTS: The main mineralogical phase of the stones in over 80% of patients was calcium oxalate monohydrate; none of the patients had pure dihydrate stones. The most frequent metabolic disorders were hypocitraturia, hypercalciuria and hyperuricosuria. Predominant risk factors were excessive body weight and insufficient fluid intake. Only one patient had an idiopathic stone formation. It was established for the first time that patients with calcium oxalate stones, containing 10 or more mass percent of apatites had statistically significantly lower daily urinary calcium and oxalate excretion and simultaneously increased phosphate excretion. CONCLUSIONS: The study findings showed that patients with calculi based on calcium oxalate dihydrate should undergo testing for daily urinary excretion of calcium and citrate while pa-tients with calcium oxalate stones containing 10 or more mass percent of apatites should also be tested for daily phosphate excretion and urine pH-profile. Daily urinary citrate excretion was reduced in all study patients, and urate excretion was significantly increased, apparently due to an imbalanced diet and excessive intake of animal protein. Menopausal and postmenopausal women are at a particular risk due to low urinary citrate excretion and high urinary calcium excretion regardless of stone composition.

[Metaphylaxis of urolithiasis - a neglected field in medicine?]

Urolithiasis is a common condition linked to lifestyle factors and its prevalence is increasing in Europe and United States. Nevertheless, recurrence of urinary stones can be effectively prevented by dietary and life style changes. The review focuses on general dietary recommendations as well as specific medical therapy for kidney stone formers.

Is in vivo analysis of urinary stone composition feasible? Evaluation of an experimental setup of a Raman system coupled to commercial lithotripsy laser fibers.

PURPOSE: Raman spectroscopy allows immediate analysis of stone composition. In vivo stone analysis during endoscopic treatment may offer advantages concerning surgical strategy and metaphylaxis. Urinary stone components were evaluated utilizing an experimental setup of a Raman system coupled to commercial laser fibers. METHODS: Samples of paracetamol (acetaminophen) and human urinary stones with known Raman spectra were analyzed using an experimental Raman system coupled to common commercial lithotripsy laser fibers (200 and 940 µm). Two different excitation lasers were used at wavelengths of 532 and 785 nm. Numerical aperture of the fibers, proportion of reflected light reaching the CCD chip, and integration times were calculated. Mathematical signal correction was performed. RESULTS: Both the laser beam profile and the quality of light reflected by the specimens were impaired significantly when used with commercial fibers. Acquired spectra could no longer be assigned to a specific stone composition. Subsequent measurements revealed a strong intrinsic fluorescence of the fibers and poor light acquisition properties leading to a significant decrease in the Raman signal in comparison with a free-beam setup. This was true for both investigated fiber diameters and both wavelengths. Microscopic examination showed highly irregular fiber tip surfaces (both new and used fibers). CONCLUSIONS: Our results propose that laser excitation and light acquisition properties of commercial lithotripsy fibers impair detectable Raman signals significantly in a fiber-coupled setting. This study provides essential physical and technological information for the development of an advanced fiber-coupled system able to be used for immediate stone analysis during endoscopic stone therapy.

Frequent gene fissions associated with human pathogenic bacteria.

Gene fusion and fission events are important for evolutionary studies and for predicting protein-protein interactions. Previous studies have shown that fusion events always predominate over fission events and, in their majority, they represent singular events throughout evolution. In this project, the role of fusion and fission events in the genome evolution of 104 human bacterial pathogens was studied. 141 protein pairs were identified to be involved in gene fusion or fission events. Surprisingly, we find that, in the species analyzed, gene fissions prevail over fusions. Moreover, while most events appear to have occurred only once in evolution, 23% of the gene fusion and fission events identified are deduced to have occurred independently multiple times. Comparison of the analyzed bacteria with non-pathogenic close relatives indicates that this impressive result is associated with the recent evolutionary history of the human bacterial pathogens, and thus is probably caused by their pathogenic lifestyle.

The optimal choice for stone analysis.

A complete investigation of urinary stone components could help to effectively evaluate and treat pathologies, and prevent recurrence. The choice of the most effective technique to use is not simple and depends on the type of sample analysed, cost and time of analysis and experience of the operator. An integrated technical approach is the best option for a stone analysis by choosing from the various techniques proposed on the basis of their characteristics, advantages and disadvantages.

[Diagnosis and treatment of nephrolithiasis. What is established?]. / Diagnostik und Therapie der Nephrolithiasis. Was ist gesichert?

BACKGROUND: Kidney stones are a common and increasing problem worldwide. Nephrolithiasis is frequently a chronic disease given the risk of recurrence following passage of a first stone. OBJECTIVES: In the present article, an update on the diagnosis and treatment of kidney stones relevant for internal medicine physicians is provided. METHODS: This review is based on a selective literature search and our own work. RESULTS AND CONCLUSION: The diagnosis of kidney stones is based on the clinical history and physical examination. Confirmatory radiologic tests include noncontrast computerized tomography or ultrasonography with both techniques having recently been shown to have equivalent overall outcomes. The therapy of kidney stones is based on the clinical presentation and diagnostic findings (e.g., fever, response to pain management, and demonstration of relevant obstruction) as well as location, size, and composition of the stone. If invasive treatment is being considered, the urology department should be consulted. Given the high risk of recurrence, stone analysis must be performed as well as the concentration of lithogenic and litholytic substances measured in a 24-h urine collection. The newly established recurrence of kidney stone nomogram (ROKS nomogram) identifies kidney stone formers at greatest risk for a second symptomatic episode who may benefit from medical intervention.

Preoperative parameters (signalment, digital radiography, urinalysis, urine microbiological culture) and novel algorithm improve prediction of canine urocystolith composition.

OBJECTIVE: To determine the accuracy of 4 preoperative parameters (signalment, urinalysis, urine microbiological culture, and digital radiography) in predicting urocystolith composition, compare accuracy between evaluators of varying clinical experience and a mobile application, and propose a novel algorithm to improve accuracy. ANIMALS: 175 client-owned dogs with quantitative analyses of urocystoliths between January 1, 2012, and July 31, 2020. METHODS: Prospective experimental study. Canine urocystolith cases were randomly presented to 6 blinded "stone evaluators" (rotating interns, radiologists, internists) in 3 rounds, each separated by 2 weeks: case data alone, case data with a urolith teaching lecture, and case data with a novel algorithm. Case data were also entered into the Minnesota Urolith Center mobile application. Prediction accuracy was determined by comparison to quantitative laboratory stone analysis results. RESULTS: Prediction accuracy of evaluators varied with experience when shown case data alone (accuracy, 57% to 82%) but improved with a teaching lecture (accuracy, 76% to 89%) and further improved with a novel algorithm (accuracy, 93% to 96%). Mixed stone compositions were the most incorrectly predicted type. Mobile application accuracy was 74%. CLINICAL RELEVANCE: Use of the 4 preoperative parameters resulted in variable accuracy of urocystolith composition predictions among evaluators. The proposed novel algorithm improves accuracy for all clinicians, surpassing accuracy of the mobile application, and may help guide patient management.

First reported magnesium pyrophosphate kidney stone prompts diagnosis of hypophosphatasia.

Hypophosphatasia (HPP) is a rare genetic condition associated with poor bone mineralization, low serum alkaline phosphatase, high urinary pyrophosphate excretion, and nephrocalcinosis. Nephrocalcinosis is thought to develop due to the increased filtered loads associated with hypercalcemia and hyperphosphatemia, but the composition of these calcifications is incompletely understood. We report the first ever magnesium pyrophosphate (MgPPi) urinary stone, which prompted the new diagnosis of HPP in a 12-year-old boy. Stone analysis labs should include infrared spectra of PPi salts in their reference libraries to facilitate identification of these rare but clinically important stones.

A Novel Infrared Spectroscopy Method for Analysis of Stone Dust for Establishing Final Composition of Urolithiasis.

Background: The introduction of the holmium laser for lithotripsy and minimally invasive techniques in endoscopy increased the popularity of stone dusting techniques. Retrieving stone pieces for an analysis increases the economic burden of surgery and operative time. Novel methods are needed for the analysis of convenient urolithiasis composition. Objective: This study aims to assess the efficacy of the stone dust Fourier transform infrared spectroscopy coupled with attenuated total reflection (FTIR ATR) method for accurate stone composition determination from the dust specimens compared with simultaneously retrieved standard stone fragments. Design setting and participants: From July 2021 to March 2022, a total of 75 patients who received endoscopic treatment for urolithiasis were included in this study. Outcome measurements and statistical analysis: The accuracy of the FTIR ATR method was assessed via estimates of sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). The results were compared between samples of stone dust and the final stone composition. Results and limitations: Total or partial biochemical composition agreement was observed in 92.7% of cases and total agreement in 82.4% of cases when stone dust was compared with stone fragments. The highest accuracy rates were obtained for uric acid stones: sensitivity 100%, specificity 98.3%, PPV 90.9%, and NPV 100%. Identification of other types of stones was also of high accuracy, reaching up to 83.3% sensitivity and 100% specificity. Conclusions: The application of FTIR ATR spectroscopy for a stone dust analysis allows obtaining easy and cost-effective final composition of urolithiasis without a stone fragment analysis. This technique was shown to be feasible, and there is substantial potential for clinical practice. Patient summary: This study investigates a novel method that determines accurate stone composition without acquiring the pieces of stone during surgery. The results have shown that stone dust Fourier transform infrared spectroscopy coupled with attenuated total reflection provides accurate stone composition.

[Urolithiasis-Therapy and recurrence prevention taking into account gender-specific aspects]. / Urolithiasis ­ Therapie und Rezidivprävention unter Berücksichtigung geschlechtsspezifischer Aspekte.

The prevalence of urolithiasis is steadily increasing worldwide in both genders. Diet and lifestyle, such as the rising prevalence of obesity and other metabolic syndrome traits, are considered key factors in this trend. Gender differences as a result of interventional therapy for urolithiasis have not been observed. However, iatrogenic injury to the male urethra is considered the most common reason for urethral strictures after endourologic (stone) therapy. In contrast, sepsis, as the major cause of urinary stone-related mortality, is more frequently reported in women after ureterorenoscopy and percutaneous nephrolithotomy. There are also differences in the frequency of various types of stones between men and women. Calcium oxalate and uric acid stones are more commonly observed in men, while carbonate apatite and struvite are diagnosed more often in women. Urinary stone analysis is therefore paramount for successful recurrence prevention. Diagnosis is based on the assignment of patients to the low-risk or high-risk group. The medical nutrition and pharmacological measures for the therapy of the respective type of stone are based on the risk factors in 24 h urine samples. A personalized approach that accounts for gender differences could further improve treatment, and recurrence prevention decisions for urinary stones.

Characteristics and Types of Urolithiasis in the Eastern Region of Saudi Arabia: A Single-Center Retrospective Study.

Introduction Urolithiasis is one of the most common conditions encountered in clinical practice with the prevalence increasing globally in the last few decades. Urolithiasis has been found to be more common in areas with a hot climate, such as Saudi Arabia. The aim of this study was to determine the characteristics and the types of urolithiasis most frequently found in the Eastern Region of Saudi Arabia. Methods This was a single-center retrospective cohort study based on data extracted from an electronic hospital information system (BESTCare) of all patients diagnosed with urolithiasis at King Abdulaziz Hospital, a tertiary care center in Saudi Arabia's Eastern Region. From January 2013 to December 2016, all adult patients aged 18 and up who presented with urinary calculi (renal and ureter) were included in the study. Results A total of 235 patients were reviewed, with a mean age of 48.52 years. Renal calculi were more prevalent in males (74.5%). Calcium oxalate was the predominant type (76%), followed by uric acid calculi (18%) and cystine calculi (4.8%). A small proportion (1.2%) was calcium phosphate calculi. The most frequently associated comorbidity was hypertension (17.9%). The majority (78.5%) had a stone removal through a ureteroscopy and 8.2% by percutaneous nephrolithotomy (PCNL). The mean stone size was 12.2 ± 9.91 mm, with a mean stone Hounsfield unit (HU) of 789.9. The mean urinary PH at stone incident was 6.77, and the mean creatinine level was 92.4mmol. Conclusion This study showed that males were more affected by urolithiasis, compared to females in the Eastern Region. Furthermore, calcium oxalate was the predominant type. These findings are consistent with the literature and they highlighted the necessity for further studies in this area, to provide insight into the pathophysiology and incidence of renal calculi for improving patient care.

Attitudes of urologists on metabolic evaluation for urolithiasis: outcomes of a global survey from 57 countries.

Although stone disease is an important health problem with high incidence and recurrence rates, it is a preventable disease. Attitudes and practices of urologists regarding the prevention of recurrence continue to be a subject of debate. In this context, an online survey study was conducted involving 305 urologists from 57 different countries. The first 7 questions collected demographic data about the urologists and the remaining 23 questions were about the recurrence and metabolic evaluation, medical treatment, and follow-up of urinary stone disease. Most urologists (85.2%) thought that metabolic examination was important. Approximately one-third of the participants (34.1%) performed 24-hour urine analysis and stone analysis was ordered by 87.5% of the urologists. Metabolic analysis was performed for all patients by 14.7% of the participants. For pediatric patients this rate was 68.5%, and for adults with recurrence the rate was 81.6%. Reasons cited by the urologists for not performing metabolic analysis included not feeling confident doing so (18.3%), having limited facilities in their hospital (26.5%), having an excessive daily workload (31.8%), patient-related factors (27.5%), and referring patients to other departments for metabolic evaluation (20.9%). Although majority of the responding urologists do consider the metabolic analysis as vital important, they seemed not to be willing to perform these tests with the same degree of enthusiasm in their daily practice. Our results show that urologists need support in performing and interpreting 24-hour urine analysis, improving their knowledge levels, and communicating with patients. Urology residency training should focus more on the prevention of urinary stone recurrence in addition to the surgical training.

How Reliable Is Endoscopic Stone Recognition? A Comparison Between Visual Stone Identification and Formal Stone Analysis.

Objective: To assess the diagnostic accuracy and intra-observer agreement of endoscopic stone recognition (ESR) compared with formal stone analysis. Introduction: Stone analysis is a corner stone in the prevention of stone recurrence. Although X-ray diffraction (XRD) and infrared spectroscopy are the recommended techniques for reliable formal stone analysis, this is not always possible, and the process takes time and is costly. ESR could be an alternative, as it would give immediate information on stone composition. Materials and Methods: Fifteen endourologists predicted stone composition based on 100 videos from ureterorenoscopy. Diagnostic accuracy was evaluated by comparing the prediction from visual assessment with stone analysis by XRD. After 30 days, the videos were reviewed again in a random order to assess intra-observer agreement. Results: The median diagnostic accuracy for calcium oxalate monohydrate was 54% in questionnaire 1 (Q1) and 59% in questionnaire 2 (Q2), whereas calcium oxalate dihydrate had a median diagnostic accuracy of 75% in Q1 and 50% in Q2. The diagnostic accuracy for calcium hydroxyphosphate was 10% in Q1 and 13% in Q2. The median diagnostic accuracy for calcium hydrogen phosphate dihydrate and calcium magnesium phosphate was 0% in both questionnaires. The median diagnostic accuracy for magnesium ammonium phosphate was 20% in Q1 and 40% in Q2. The median diagnostic accuracy for uric acid was 22% in both questionnaires. Finally, there was a diagnostic accuracy of 60% in Q1 and 80% in Q2 for cystine. The intra-observer agreement ranged between 45% and 72%. Conclusion: Diagnostic accuracy of ESR is limited and intra-observer agreement is below the threshold of acceptable agreement.

Thulium Fiber Laser's Dust for Stone Composition Analysis: Is It Enough? A Pilot Study.

Introduction: We aimed to evaluate if the biochemical composition of urinary stones can be determined by analyzing the stone dust only, and whether a photo taken during the surgery could be useful for completing the morpho-constitutional analysis. Materials and Methods: Twenty patients went through a retrograde intrarenal surgery for renal stone treatment with thulium fiber laser (Fiber Dust; Quanta, 2020) using 150 µm silica core laser fibers. After laser lithotripsy, residual fragments (RF) were removed with a basket (ZeroTip; Boston Scientific) and spontaneously floating stones particles were considered stone dust and were aspirated through the working channel. Pairs of RF and stone dust were labeled and sent to analysis by scanning electron microscopy and Fourier transform infrared spectroscopy. Photos of the stone (surface and section) were taken from videos recorded during the surgery. Results: A total of 20 patients were included in this study. Mean age was 49.8 years with metabolic and genetic disorders. Mean stone volume was 750 mm3 for ureteral stones and 2334 mm3 for renal stones. Mean stone density was 1187 HU. Positive urine culture was found in 25% patients. In 2/20 (10%), the biochemistry differed only in the relative proportions of each constituent, while in 5/20 (25%), only one component was missing. Laser crystalline conversion was found in 3/20 (15%). Whewellite and weddellite layers were found in photos, thus adding missing information from dust stone analysis. Conclusion: By analyzing aspirated dust through the ureteroscope's working channel with physical techniques, we can understand the lithogenic process of the urinary stone, without needing to analyze the stone fragment. Morphologic analysis, given by a proper stone picture, adds missing information in specific cases.

Urine and stone analysis for the investigation of the renal stone former: a consensus conference.

The Consensus Group deliberated on a number of questions concerning urine and stone analysis over a period of months, and then met to develop consensus. The Group concluded that analyses of urine and stones should be routine in the diagnosis and treatment of urinary stone diseases. At present, the 24-h urine is the most useful type of urine collection, and accepted methods for analysis are described. Patient education is also important for obtaining a proper urine sample. Graphical methods for reporting urine analysis results can be helpful both for the physician and for educating the patient as to proper dietary changes that could be beneficial. Proper analysis of stones is also essential for diagnosis and management of patients. The Consensus Group also agreed that research has shown that evaluation of urinary crystals could be very valuable, but the Group also recognizes that existing methods for assessment of crystalluria do not allow this to be part of stone treatment in many places.