Exploring the association between multiple factors and urolithiasis: A retrospective study and Mendelian randomization analysis.

To investigate the relationship between several factors and urinary stone as well as different stone compositions. To guide the diagnosis, treatment, and prevention of urinary stone recurrence. We used bidirectional Mendelian randomization to analyze the causal relationship between hypertension and urinary stones, diabetes and urinary stones, and body mass index (BMI) and urinary stones. We retrospectively analyzed the medical records of patients with urinary stones admitted to a tertiary care hospital in Chongqing, China, from July 2015 to October 2022. Patients were included when they were first diagnosed with urinary stones. The odds ratio of calculi on hypertension estimated by inverse variance weighted was 8.46 (95%CI: 4.00-17.90, P = 2.25 × 10-8). The stone composition analysis showed that there were 3101 (67.02%) mixed, 1322 (28.57%) calcium oxalate monohydrate, 148 (3.20%) anhydrous uric acid, 16 (0.35%) magnesium ammonium phosphate hexahydrate, 11 (0.24%) dicalcium phosphate dihydrate, 10 (0.22%) carbonate apatite, 8 (0.17%) L-cystine, 4 ammonium uric acid (0.09%), and 7 other stone types (0.15%). Mendelian randomization studies have proven that urinary stones may be a potential risk factor for hypertension, while there is no causal relationship between diabetes and stones, BMI, and stones. Our retrospective study has shown that urinary stone components are closely associated with sex, age, hypertension, diabetes, and BMI. It is reasonable to suspect that treating a single stone component is ineffective in preventing recurrence. We also found that the peak incidence of urinary stones was at the most active stage of most people's working lives.

What is the definition of stone dust and how does it compare with clinically insignificant residual fragments? A comprehensive review.

PURPOSE: During endoscopic stone surgery, Holmium:YAG (Ho:YAG) and Thulium Fiber Laser (TFL) technologies allow to pulverize urinary stones into fine particles, ie DUST. Yet, currently there is no consensus on the exact definition of DUST. This review aimed to define stone DUST and Clinically Insignificant Residual Fragments (CIRF). METHODS: Embase, MEDLINE (PubMed) and Cochrane databases were searched for both in vitro and in vivo articles relating to DUST and CIRF definitions, in November 2023, using keyword combinations: "dust", "stones", "urinary calculi", "urolithiasis", "residual fragments", "dusting", "fragments", "lasers" and "clinical insignificant residual fragments". RESULTS: DUST relates to the fine pulverization of urinary stones, defined in vitro as particles spontaneously floating with a sedimentation duration ≥ 2 sec and suited for aspiration through a 3.6Fr-working channel (WC) of a flexible ureteroscope (FURS). Generally, an upper size limit of 250 µm seems to agree with the definition of DUST. Ho:YAG with and without "Moses Technology", TFL and the recent pulsed-Thulium:YAG (pTm:YAG) can produce DUST, but no perioperative technology can currently measure DUST size. The TFL and pTm:YAG achieve better dusting compared to Ho:YAG. CIRF relates to residual fragments (RF) that are not associated with imminent stone-related events: loin pain, acute renal colic, medical or interventional retreatment. CIRF size definition has decreased from older studies based on Shock Wave Lithotripsy (SWL) (≤ 4 mm) to more recent studies based on FURS (≤ 2 mm) and Percutaneous Nephrolithotomy(PCNL) (≤ 4 mm). RF ≤ 2 mm are associated with lower stone recurrence, regrowth and clinical events rates. While CIRF should be evaluated postoperatively using Non-Contrast Computed Tomography(NCCT), there is no consensus on the best diagnostic modality to assess the presence and quantity of DUST. CONCLUSION: DUST and CIRF refer to independent entities. DUST is defined in vitro by a stone particle size criteria of 250 µm, translating clinically as particles able to be fully aspirated through a 3.6Fr-WC without blockage. CIRF relates to ≤ 2 RF on postoperative NCCT.

Stone centers: a national survey on surgical techniques performed in Italy.

BACKGROUND: Recurrent and complex stone disease may be considered a challenging disease. In 2018, the Calculus group of the SIU (Italian Society of Urology) set itself the goal of establishing the minimum requirements for a center that could continuously manage urolithiasis pathology, named a Stone Center. In this study we present the results of a pilot survey carried out in 2019 with the aim of drawing a map of the situation of Italian urological centers dealing with urinary stones. METHODS: A total of 260 national urology departments dealing with urolithiasis surgery were contacted for this study. A survey was issued to each of the centers to determine the number of patients treated for urinary stones and the amount of procedures performed per year: 1) extracorporeal shock wave lithotripsy ESWL; 2) ureterorenoscopy URS; 3) retrograde intrarenal surgery RIRS; 4) percutaneous nephrolithotomy PCNL. RESULTS: Out of 260 centers contacted, 188 fulfilled the survey. Outcomes were quite variable, with approximately 37% of the centers lacking a lithotripter, and 46% of those that did have it performing fewer than 100 treatments per year. In terms of endoscopic procedures, more than 80% of the centers contacted performed URS or RIRS; however, when it came to percutaneous lithotripsy, these numbers dropped significantly; 33% of the centers contacted did not perform PCNL, and of those who did, 18% had less than 5 years of experience as a center. CONCLUSIONS: Our survey shows a very heterogeneous national picture about urolithiasis treatments. Our goal is to create national paradigms to be able to define stone centers where the patient suffering from complex urinary stones can find a network of professionals with an adequate armamentarium suitable for the management of their pathology.

A nomogram clinical prediction model for predicting urinary infection stones: development and validation in a retrospective study.

PURPOSE: This study aimed to develop a nomogram prediction model to predict the exact probability of urinary infection stones before surgery in order to better deal with the clinical problems caused by infection stones and take effective treatment measures. METHODS: We retrospectively collected the clinical data of 390 patients who were diagnosed with urinary calculi by imaging examination and underwent postoperative stone analysis between August 2018 and August 2023. The patients were randomly divided into training group (n = 312) and validation group (n = 78) using the "caret" R package. The clinical data of the patients were evaluated. Univariate and multivariate logistic regression analysis were used to screen out the independent influencing factors and construct a nomogram prediction model. The receiver operating characteristic curve (ROC), calibration curves, and decision curve analysis (DCA) and clinical impact curves were used to evaluate the discrimination, accuracy, and clinical application efficacy of the prediction model. RESULTS: Gender, recurrence stones, blood uric acid value, urine pH, and urine bacterial culture (P < 0.05) were independent predictors of infection stones, and a nomogram prediction model ( https://zhaoyshenjh.shinyapps.io/DynNomInfectionStone/ ) was constructed using these five parameters. The area under the ROC curve of the training group was 0.901, 95% confidence interval (CI) (0.865-0.936), and the area under the ROC curve of the validation group was 0.960, 95% CI (0.921-0.998). The results of the calibration curve for the training group showed a mean absolute error of 0.015 and the Hosmer-Lemeshow test P > 0.05. DCA and clinical impact curves showed that when the threshold probability value of the model was between 0.01 and 0.85, it had the maximum net clinical benefit. CONCLUSIONS: The nomogram developed in this study has good clinical predictive value and clinical application efficiency can help with risk assessment and decision-making for infection stones in diagnosing and treating urolithiasis.

Develop a radiomics-based machine learning model to predict the stone-free rate post-percutaneous nephrolithotomy.

Radiomics and machine learning have been extensively utilized in the realm of urinary stones, particularly in forecasting stone treatment outcomes. The objective of this study was to integrate clinical variables and radiomic features to develop a machine learning model for predicting the stone-free rate (SFR) following percutaneous nephrolithotomy (PCNL). A total of 212 eligible patients who underwent PCNL surgery at the Second Affiliated Hospital of Nanchang University were included in a retrospective analysis. Preoperative clinical variables and non-contrast-enhanced CT images of all patients were collected, and radiomic features were extracted after delineating the stone ROI. Univariate analysis was conducted to identify clinical variables strongly correlated with the stone-free rate after PCNL, and the least absolute shrinkage and selection operator algorithm (lasso regression) was utilized to screen radiomic features. Four supervised machine learning algorithms, including Logistic Regression, Random Forest (RF), Extreme Gradient Boosting (XGBoost), and Gradient Boosting Decision Tree (GBDT), were employed. The clinical variables with strong correlation and screened radiomic features were integrated into the four machine learning algorithms to construct a prediction model, and the receiver operating curve was plotted. The area under the receiver operating curve (AUC), the accuracy rate, the specificity, etc., were used to evaluate the predictive performance of the four models. After analyzing postoperative statistics, the stone-free rate following the procedure was found to be 70.3% (n = 149). Among the various clinical variables examined, factors, such as stone number, stone diameter, stone CT value, stone location, and history of stone surgery, were identified as statistically significant in relation to the stone-free rate after PCNL. A total of 121 radiomic features were extracted, and through lasso regression, 7 features most closely associated with the stone-free rate post-PCNL were identified. The predictive accuracy of different models (Logistic Regression, RF, XGBoost, and GBDT) for determining the stone-free rate after PCNL was evaluated, yielding accuracies of 78.1%, 76.6%, 75.0%, and 73.4%, respectively. The corresponding area under the curve AUC (95%CI) were 0.85 (0.83-0.89), 0.81 (0.76-0.85), 0.82 (0.78-0.85), and 0.77 (0.73-0.81), positioning these models among the top performers in logistic regression prediction. In terms of predictive importance scores, the key factors identified by the logistic regression model were number of stone, zone percentage, stone diameter, and surface area. Similarly, the RF model highlighted number of stone, stone CT value, stone diameter, and surface area as the top predictors. Among the four machine learning models, the logistic regression model demonstrated the highest accuracy and discrimination ability in predicting the stone-free rate following PCNL. In comparison to XGBoost and GBDT, RF also exhibited superior accuracy and a certain level of discrimination ability. However, based on the performance of all four models, logistic regression is more likely to aid in clinical decision-making by assisting clinicians in diagnosing PCNL in patients. This enables us to effectively predict the presence of residual stones post-surgery and ultimately select patients who are suitable candidates for PCNL.

Effects of body mass index on urinary lithogenic factors in urinary system stone patients.

AIM: Obesity and metabolic syndrome are becoming more prevalent these days. In addition, we know that urinary stone disease is also on the rise. In this study, we wanted to examine if body mass index (BMI) had a negative effect on the stone disease by evaluating 24-hour urinalysis in stone patients and recurrence rates in our region.

Establishment and application of a nomogram diagram for predicting calcium oxalate stones in patients with urinary tract stones.

This retrospective study aims to examine the correlation between calcium oxalate (CaOx) stones and common clinical tests, as well as urine ionic composition. Additionally, we aim to develop and implement a personalized model to assess the accuracy and feasibility of using charts to predict calcium oxalate stones in patients with urinary tract stones. A retrospective analysis was conducted on data from 960 patients who underwent surgery for urinary stones at the First Affiliated Hospital of Soochow University from January 1, 2010, to December 31, 2022. Among these patients, 447 were selected for further analysis based on screening criteria. Multivariate logistic regression analysis was then performed to identify the best predictive features for calcium oxalate stones from the clinical data of the selected patients. A prediction model was developed using these features and presented in the form of a nomogram graph. The performance of the prediction model was assessed using the C-index, calibration curve, and decision curve, which evaluated its discriminative power, calibration, and clinical utility, respectively. The nomogram diagram prediction model developed in this study is effective in predicting calcium oxalate stones which is helpful in screening and early identification of high-risk patients with calcium oxalate urinary tract stones, and may be a guide for urologists in making clinical treatment decisions.

Follow-up of urolithiasis patients after treatment: an algorithm from the EAU Urolithiasis Panel.

OBJECTIVE: To develop a follow-up algorithm for urinary stone patients after definitive treatment. MATERIALS AND METHODS: The panel performed a systematic review on follow-up of urinary stone patients after treatment (PROSPERO: CRD42020205739). Given the lack of comparative studies we critically evaluated the literature and reached a consensus on the follow-up scheme. RESULTS: A total of 76 studies were included in the analysis, including 17 RCTs. In the stone-free general population group, 71-100% of patients are stone-free at 12 months while 29-94% remain stone-free at 36 months. We propose counselling these patients on imaging versus discharge after the first year. The stone-free rate in high-risk patients not receiving targeted medical therapy is < 40% at 36 months, a fact that supports imaging, metabolic, and treatment monitoring follow-up once a year. Patients with residual fragments ≤ 4 mm have a spontaneous expulsion rate of 18-47% and a growth rate of 10-41% at 12 months, supporting annual imaging follow-up. Patients with residual fragments > 4 mm should be considered for surgical re-intervention based on the low spontaneous expulsion rate (13% at 1 year) and high risk of recurrence. Plain film KUB and/or kidney ultrasonography based on clinicians' preference and stone characteristics is the preferred imaging follow-up. Computed tomography should be considered if patient is symptomatic or intervention is planned. CONCLUSIONS: Based on evidence from the systematic review we propose, for the first time, a follow-up algorithm for patients after surgical stone treatment balancing the risks of stone recurrence against the burden of radiation from imaging studies.

Composition analysis of renal and ureteral calculi in a single center in northern China in the past decade.

The current report aimed to evaluate the characteristics of stone composition in 3637 renal and ureteral calculi patients in a single center while clarifying its relationship with sex, age, and time. Out of 3637 cases of upper urinary tract stones, stone specimens were analyzed retrospectively. There were 2373 male patients aged 6 months-87 years, with an average age of 44.73 ±â€…15.63 years, and 1264 female patients aged 4 months-87 years, with an average age of 46.84 ±â€…16.00 years. The male-female ratio was 1.88:1. Five hundred twelve patients had ureteral calculi, and 3125 had renal calculi. The SPSS software helped analyze the relationship between renal and ureteral calculi composition and sex, age, and time. Stone composition demonstrated 2205 cases of calcium oxalate stones (60.6%), 518 carbonate apatite (14.2%), 386 uric acids (10.6%), 232 magnesium ammonium phosphate (6.4%), 117 calcium phosphate (3.2%), 76 cystine (2.1%), 47 sodium urate (1.3%), 31 others (0.9%), and 25 ammonium urate (0.7%) cases. The overall male-to-female sex ratio was 1.88:1. Stones in the upper urinary tract were significantly more frequent in men than in women between the ages of 31 and 60. However, such stones were significantly more frequent in women than men over 80 (P < .05). Cystine, Sodium urate, Carbonated apatite, and uric acid indicated significant differences between different age categories (all P < .001). Stone composition analyses revealed that the frequency of calcium oxalate calculi has increased annually, while cystine and carbonated apatite incidences have dropped annually over the past decade. The components of renal and ureteral calculi vary significantly based on age and sex, with calcium oxalate calculi being more frequent in men while magnesium ammonium phosphate stones are more frequent in female patients. The age between 31 and 60 years is the most prevalent for renal and ureteral calculi in men and women.

Surgical procedure and recurrence of upper urinary tract stone: a national-wide study based on hospitalized patients.

PURPOSE: This study aimed to investigate the influence of surgical intervention on recurrence risk of upper urinary tract stone and compare the medical burden of various surgical procedures. METHODS: This study analyzed data from patients with upper urinary tract stone extracted from a national database of hospitalized patients in China, from January 2013 to December 2018. Surgical recurrence was defined as patients experience surgical procedures for upper urinary tract stone again with a time interval over 90 days. Associations of surgical procedures with surgical recurrence were evaluated by Cox regression. RESULTS: In total, 556,217 patients with upper urinary tract stone were included in the present analysis. The mean age of the population was 49.9 ± 13.1 years and 64.1% were men. During a median follow-up of 2.7 years (IQR 1.5-4.0 years), 23,012 patients (4.1%) had surgical recurrence with an incidence rate of 14.9 per 1000 person-years. Compared to patients receiving open surgery, ESWL (HR, 1.59; 95% CI 1.49-1.70), URS (HR, 1.38; 95% CI 1.31-1.45), and PCNL (HR, 1.11; 95% CI 1.06-1.18) showed a greater risk for surgical recurrence. Patients receiving ESWL had the shortest hospital stay length and the lowest cost among the 4 procedures. CONCLUSIONS: Compared with open surgery, ESWL, URS, and PCNL are associated with higher risks of surgical recurrence for upper urinary tract stone, while ESWL showed the least medical burden including both expenditure and hospital stay length. How to keep balance of intervention efficacy and medical expenditure is an important issue to be weighed cautiously in clinic practice and studied more in the future.

Evaluation of Factors Influenced on the Effectiveness of Percutaneous Nephrolithotomy.

Background: Generally, there are many methods for the treatment of urinary stones, of which percutaneous nephrolithotomy (PCNL) is a minimally invasive and highly effective method, and now become the first-line management for urinary stones, especially in the cases of complex stones and staghorne calculi. Accurate assessment of stone location, stone morphology, degree of hydronephrosis as well as urinary system abnormalities is extremely important in the percutaneous nephrolithotomy strategy. Objective: The aim of this study was to evaluate the S.T.O.N.E score as well as other factors that influenced the effectiveness of PCNL. Methods: Descriptive study on 71 patients with kidney stones, who underwent multi-slice CT scan of the urinary system before PCNL and then PCNL at Hanoi Medical University Hospital from July 2022 to July 2023. All patients received the informed consent and agreed to participate in the study. The factors included the stone area, the track length (from the skin surface to the stone central), the degree of urinary tract dilatation, the number of involved calyces, the density of stone, the renal parenchyma thickness, the ureteral wall thickness and fat infiltration measured on MSCT non-contrast phase. These factors were used to predict the effectiveness of PCNL including the stone clearance rate (SCR) and the operation time. Results: The mean age of the patient group was 53.8±12.3. The male/female ratio was 1.54. There was a significant difference (p<0.05) between the following factors and the operation time: the stone area (<400, 400-799, 800-1599 and >1600 mm2), the degree of urinary tract dilatation (no or might and moderate or severe dilatation), the number of involved calyces (≤ 2, 3 and staghorne calculi), the renal parenchyma thickness (<18 mm and ≥18mm). In contrast, there were no significant differences between the following factors and the surgery time (p>0.05): the track length (<100 and ≥100 mm), and the stone density (<950 and ≥950 HU). Regarding the S.T.O.N.E score (included five factors: Size, Track length, Obstruction, Number of involved calyces, and Evaluation of stone density), there was a strong correlation between S.T.O.N.E score and the surgery time (p<0.001, r=0.94), and the SCR (p=0.001, r=-0.97). Conclusion: The evaluation of these factors played an important role in the prediction of the effectiveness of PCNL.

Comparing outcomes of single-use vs reusable ureteroscopes: a systematic review and meta analysis.

Flexible ureterolithotripsy is a frequent urological procedure, usually used to remove stones from the kidney and upper ureter. Reusable uretero-scopes were the standard tool for that procedure, but recent concerns related to sterility and maintenance and repair costs created the opportunity to develop new technologies. In 2016, the first single-use digital flexible ureteroscope was introduced. Since then, other single-use ureteroscopes were developed, and studies compared them with the reusable ureteroscopes with conflicting results. The purpose of this study is to describe the literature that compares the performance of single-use and reusable flexible ureteroscopes in retrograde intrarenal surgery for urinary stones. A Systematic Review was performed in October 2022 in accordance with the Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA). A search in MEDLINE, EMBASE, Web of Science, Google Scholar and LILACS retrieved 10,039 articles. After screening, 12 articles were selected for the Meta-Analysis. No differences were found in stone-free rate (OR 1.31, CI 95% [0.88, 1.97]), operative time (MD 0.12, CI 95% [-5.52, 5.76]), incidence of post-operative fever (OR 0.64, CI 95% [0.22, 1.89]), or incidence of post-operative urinary tract infection (OR 0.63 CI 95% [0.30, 1.32]). No differences were observed in the studied variables. Hence, the device choice should rely on the availability, cost analysis and surgeons' preference.

Preventive Pharmacological Therapy and Risk of Recurrent Urinary Stone Disease.

BACKGROUND: Urinary stone disease is a prevalent condition associated with a high recurrence risk. Preventive pharmacological therapy has been proposed to reduce recurrent stone episodes. However, limited evidence exists regarding its effectiveness, contributing to its underutilization by physicians. This study aimed to evaluate the association between preventive pharmacological therapy (thiazide diuretics, alkali therapy, and uric acid-lowering medications) and clinically significant urinary stone disease recurrence. METHODS: Using data from the Veterans Health Administration, adults with an index episode of urinary stone disease from 2012 through 2019 and at least one urinary abnormality (hypercalciuria, hypocitraturia, or hyperuricosuria) on 24-hour urine collection were included. The primary outcome was a composite variable representing recurrent stone events that resulted in emergency department visits, hospitalizations, or surgery for urinary stone disease. Cox proportional hazards regression was performed to estimate the association between preventive pharmacological therapy use and recurrent urinary stone disease while adjusting for relevant baseline patient characteristics. RESULTS: Among the cohort of patients with urinary abnormalities ( n =5637), treatment with preventive pharmacological therapy was associated with a significant 19% lower risk of recurrent urinary stone disease during the 12-36-month period after the initial urine collection (hazard ratio, 0.81; 95% confidence interval, 0.65 to 1.00; P = 0.0496). However, the effectiveness of preventive pharmacological therapy diminished over longer follow-up periods (12-48 and 12-60 months after the urine collection) and did not reach statistical significance. When examining specific urinary abnormalities, only alkali therapy for hypocitraturia was associated with a significant 26% lower recurrence risk within the 12-36-month timeframe (hazard ratio, 0.74; 95% confidence interval, 0.56 to 0.97; P = 0.03). CONCLUSIONS: When considering all urinary abnormalities together, this study demonstrates that the use of preventive pharmacological therapy is associated with a lower risk of clinically significant recurrent episodes of urinary stone disease in the 12-36 month timeframe after urine collection, although only the association with the use of alkali therapy for hypocitraturia was significant when individual abnormalities were examined.

[Two Cases of Ammonium Acid Urate Urinary Stones That Could Not Be Diagnosed by Dual-Energy Computed Tomography].

We report two cases of ammonium acid urate stones that could not be diagnosed by dual-energy computed tomography (CT). Case 1: A 37-year-old female was referred to our hospital for a left kidney stone. She had a medical history of anorexia nervosa, Basedow's disease and hypoparathyroidism. Her height was 167 cm, weight 38 kg and body mass index (BMI) 13. 6. CT showed a left kidney stone measuring 18×12 mm. Dual-energy CT showed that the left kidney stone was composed of uric acid. Chemolysis by oral administration of alkaline citrate was attempted. Six months later, CT showed no improvement, and endoscopic combined intrarenal surgery (ECIRS) was performed. Stone analysis revealed pure ammonium acid urate. Case 2: A 42-year-old female was referred to our hospital because of right back pain. She had a medical history of ventricular septal defect and urolithiasis. Her height was 158 cm, weight 37 kg, and BMI 14.8. CT showed a right kidney stone measuring 16×12 mm. Dual-energy CT showed that the right kidney stone was composed of uric acid. Chemolysis by oral administration of alkaline citrate was attempted. Two months later, CT showed no improvement, and ECIRS was performed. Stone analysis revealed pure ammonium acid urate. It is difficult to differentiate uric acid stones and ammonium acid urate stones by dual-energy CT. Even when dual-energy CT suggests uric acid stones, ammonium acid urate stones should also be considered in thin young women and women with a history of anorexia nervosa.

RIRS with FV-UAS vs. MPCNL for 2-3-cm upper urinary tract stones: a prospective study.

To observe the efficacy and safety of retrograde intrarenal surgery (RIRS) combined with flexible vacuum-assisted ureteral access sheath (FV-UAS) and minimally invasive percutaneous nephrolithotomy (MPCNL) in patients with 2-3 cm upper urinary tract stones. A total of 160 patients with 2-3 cm upper urinary tract stones were prospectively randomized into 2 groups-80 in the FV-UAS group and 80 cases as control in the MPCNL group. The stone-free rates (SFRs) at different times (postoperative 1st day and 4th week) were considered as the primary outcome of the study. The secondary end points were operative time, hemoglobin decrease, postoperative hospital stay, and operation-related complications. There was no obvious difference between the two groups in patient's demographics and preoperative clinical characteristics (all P > 0.05). Postoperative data showed that mean decrease in hemoglobin level was less in FV-UAS group than that in MPCNL group (5.3 vs. 10.8 g/L, P < 0.001). Postoperative hospital stay in FV-UAS group was more shorten than that in MPCNL group (2.7 vs. 4.9 days, P < 0.001). There was no statistical significance between the two groups in SFRs during postoperative 1st day and 4th week (both P > 0.05). However, in terms of the rates of bleeding and pain, MPCNL group were both significantly higher than FV-UAS group (6.2 vs. 0.0%, P = 0.023; 16.2 vs. 2.5%, P = 0.003; respectively). Our study showed that RIRS with FV-UAS, a new partnership to treat 2-3 cm upper urinary tract stones, was satisfying as it achieved a high SFR rate and a low rate of complications. This method was safe and reproducible in clinical practice.

Risk assessment and prevention of urolithiasis in urban areas of Baoding, China.

Urolithiasis, or the formation of calculi in the urinary system, represents a prevalent urological condition frequently encountered among individuals aged 30 to 55 years. An in-depth analysis of the composition of these calculi holds significant promise in shedding light on the underlying etiological and pathogenic factors contributing to this ailment. The primary objective of this study was to delineate the principal components comprising urinary system calculi within a cohort of patients who sought medical intervention at a tertiary grade A hospital located in Baoding City. Furthermore, our investigation entailed a comprehensive examination of the physical and morphological characteristics exhibited by these calculi. In this study, a total of 2307 individuals afflicted with urinary system calculi were recruited as participants, and a corresponding number of 2307 calculous specimens were subjected to thorough examination. The specimens were examined using infrared spectroscopy. We collected and examined patient data including gender, age, location of the calculi, employment status, residential area, and other factors. The middle-aged demographic exhibited a conspicuous predilection for urinary system calculi, wherein a notable gender disparity was observed, with a male-to-female ratio of 1.63 to 1. Among the enrolled patients, kidney calculi were prevalent in 1270 cases, ureteral calculi were documented in 983 cases, and bladder calculi were encountered in 46 instances. Notably, the principal components comprising these calculi were identified as calcium oxalate and apatite, while uric acid and ammonium magnesium phosphate were comparatively less frequently encountered. Furthermore, the analysis of calculus composition across patients residing in distinct geographical regions did not reveal any statistically significant variations. The identification of components within upper urinary tract calculi plays a pivotal role in elucidating the root causes of calculus formation. This valuable information empowers healthcare professionals, particularly nursing staff, to provide personalized dietary and health guidance to patients, thereby enhancing the quality of care and promoting more effective management of this condition.

Place of urolithiasis in the spectrum of urological pathologies, practices and use of endourological procedures in the management of calculi of the upper urinary tract: results of a survey of referral centres in Africa.

Our aim was to determine the current trend of endourology in the management of upper urinary tract calculi in Africa reference centres. We conducted an online multiple-choice questionnaire survey involving 46 centres from 27 countries using a structured well-designed Google Form (®) questionnaire. The questionnaires were distributed to the head of service through their emails. The questions collected demographic data about the centre, the epidemiology of urolithiasis, diagnostic means and management of upper urolithiasis, especially access to endourology procedures and their practices. Descriptive analyses were performed. The participation rate was 77.9%. Urinary lithiasis was one of the three main pathologies encountered in 42/46 centres. 33 centres had easy access to CT scanners and 34 had operating theatres equipped with endo-urological surgery equipment. Of these 34 centres, 30 perform endourology for the management of upper urinary tract stones. Rigid ureteroscopy is the main technique used by the centres. It is the only endourology technique used for stone management by 12 centres (40%). 7/30 (23.3%) have the option of performing rigid ureteroscopy, flexible ureteroscopy and percutaneous nephrolithotomy. The frequency of procedures varies widely, with 43.3% rarely performing endourological surgery. Seventeen centres have their operating theatre equipped with a fluoroscope and 6/42 centres have extracorporeal lithotripsy. Open surgery is still used in 29/42 centres (69.1%). Laparoscopy is available in 50% of centres, but none reported performing laparoscopic lithotomy. In Africa, urinary lithiasis plays an important role in the activities of referral centres. Modern management techniques are used to varying degrees (not all centres have them) and with very variable frequency. Open surgery is still widely performed as a management. Rigid ureteroscopy is the main endourological technique. It is essential to develop the practice of modern urology in Africa, mainly endourology.

Intestinal Oxalate Absorption, Enteric Hyperoxaluria, and Risk of Urinary Stone Formation in Patients with Crohn's Disease.

Nephrolithiasis is a common urologic manifestation of Crohn's disease. The purpose of this study was to investigate the clinical characteristics, intestinal oxalate absorption, and risk factors for urinary stone formation in these patients. In total, 27 patients with Crohn's disease and 27 healthy subjects were included in the present study. Anthropometric, clinical, and 24 h urinary parameters were determined, and the [13C2]oxalate absorption test was performed. Among all patients, 18 had undergone ileal resection, 9 of whom had a history of urinary stones. Compared to healthy controls, the urinary excretion values of calcium, magnesium, potassium, sulfate, creatinine, and citrate were significantly lower in patients with Crohn's disease. Intestinal oxalate absorption, the fractional and 24 h urinary oxalate excretion, and the risk of calcium oxalate stone formation were significantly higher in patients with urolithiasis than in patients without urolithiasis or in healthy controls. Regardless of the group, between 83% and 96% of the [13C2]oxalate was detected in the urine within the first 12 h after ingestion. The length of ileum resection correlated significantly with the intestinal absorption and urinary excretion of oxalate. These findings suggest that enteric hyperoxaluria can be attributed to the hyperabsorption of oxalate following extensive ileal resection. Oral supplementation of calcium and magnesium, as well as alkali citrate therapy, should be considered as treatment options for urolithiasis.

How much energy do we need to ablate 1 cubic millimeter of stone during Thulium Fiber Laser lithotripsy? An in vitro study.

INTRODUCTION: Both Holmium:yttrium-aluminium-garnet (Ho:YAG) laser and Thulium Fiber Laser (TFL) can effectively treat all urinary stone types. This in vitro study evaluated the ablation volume per pulse (AVP) and required energy needed to ablate 1mm3 (RE, J/mm3) of various stone types at different laser settings with TFL. METHODS: 272-µm core-diameter laser fibers (Boston Scientific©) were connected to a 50 Watts TFL generator (IPG®). An experimental setup immerged human stones of calcium oxalate monohydrate (COM), uric acid (UA), and cystine (CYS) with a single pulse lasing emission (0.5/0.8/1 J), in contact mode. Stones were dried out before three-dimensional scanning to measure AVP and deduce from the pulse energy (PE) and AVP the RE. A direct comparison with known Ho:YAG's AVP and RE was then carried out. RESULTS: AVP for COM stones was significantly greater than those for CYS stones and similar to UA stones (p = 0.02 and p = 0.06, respectively). If AVP increased with PE against COM and UA stones, AVP decreased against CYS stones. 1 J PE resulted in a threefold lower RE compared with other PE for COM stones. On the contrary, RE for CYS increased with PE, whereas PE did not had influence on RE for UA. TFL was associated with greater AVP for COM, but lower for UA and CYS stones compared to Ho:YAG laser. CONCLUSION: This in vitro study firstly describes the ablation volume per pulse and required energy to treat a cubic millimeter of three frequent human stone types, and suggest TFL could not be suited for cystine. Therefore, stone composition could be considered when choosing the laser source for lithotripsy.