Real-World Effectiveness of Preventive Pharmacological Therapy in Patients With Urolithiasis: A Retrospective Cohort Study.

RATIONALE & OBJECTIVE: Data supporting the efficacy of preventive pharmacological therapy (PPT) to reduce urolithiasis recurrence are based on clinical trials with composite outcomes that incorporate imaging findings and have uncertain clinical significance. This study evaluated whether the use of PPT leads to fewer symptomatic stone events. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Medicare enrollees with urolithiasis who completed 24-hour urine collections that revealed hypercalciuria, hypocitraturia, low urine pH, or hyperuricosuria. EXPOSURE: PPT (thiazide diuretics for hypercalciuria, alkali for hypocitraturia or low urine pH, or uric acid lowering drugs for hyperuricosuria) categorized as (1) adherent to guideline-concordant PPT, (2) nonadherent to guideline-concordant PPT, or (3) untreated. OUTCOME: Symptomatic stone event occurrence (emergency department [ED] visit or hospitalization for urolithiasis or stone-directed surgery). ANALYTICAL APPROACH: Cox proportional hazards regression. RESULTS: Among 13,942 patients, 31.0% were prescribed PPT. Compared with no treatment, concordant/adherent PPT use was associated with a significantly lower hazard of symptomatic stone events for patients with hypercalciuria (HR, 0.736 [95% CI, 0.593-0.915]) and low urine pH (HR, 0.804 [95% CI, 0.650-0.996]) but not for patients with hypocitraturia or hyperuricosuria. These associations were largely driven by significantly lower rates of ED visits after initiating PPT among the concordant/adherent group versus untreated patients. Patients with hypercalciuria had adjusted 2-year predicted probabilities of a visit of 3.8% [95% CI, 2.5%-5.2%%] and 6.9% [95% CI, 6.0%-7.7%] for the concordant/adherent PPT and no-treatment groups, respectively. Among patients with low urine pH, these probabilities were 4.3% (95% CI, 2.9%-5.7%) and 7.3% (95% CI, 6.5%-8.0%) for the concordant/adherent PPT and no-treatment groups, respectively. LIMITATIONS: Potential bias from the possibility that patients prescribed PPT had more severe disease than untreated patients. CONCLUSIONS: Patients with urolithiasis and hypercalciuria who were adherent to treatment with thiazide diuretics as well as those with low urine pH adherent to prescribed alkali therapy had fewer symptomatic stone events than untreated patients. PLAIN-LANGUAGE SUMMARY: Despite multiple clinical trials demonstrating the efficacy of thiazide diuretics and alkali for secondary prevention of kidney stones, they are infrequently prescribed due in part to a lack of data about their effectiveness in real-world settings. We analyzed medical claims from older adults with kidney stones for whom urine chemistry data were available. We found that patients who took prescribed thiazide diuretics for elevated urine calcium levels or alkali for low urinary pH were less likely to experience symptomatic stone recurrences than untreated patients. This benefit was expressed as lower rates of emergency department visits after initiating therapy. Our findings should inform the prescription of and adherence to treatment with thiazide diuretics and alkali for the prevention of recurrent kidney stones.

First clinical evaluation of a flexible digital ureteroscope with direct in scope suctioning system (Pusen DISS 7.5Ch): prospective multicentric feasibility study.

PURPOSE: A new digital single-use flexible ureteroscope, Pusen direct in scope suction (DISS) 7.5Fr (PU3033AH), was evaluated with respect to manoeuvrability, suction quality, visibility and clinical efficiency. METHODS: A prospective cohort study was conducted in six tertiary reference centers in Europe and Asia between February-April 2024. Adult patients who underwent flexible ureteroscopy and laser lithotripsy (fURSL) for urolithiasis were included. Demographic, intraoperative and follow-up characteristics were recorded. Quality parameters were rated by each surgeon using a Likert scale. RESULTS: a total of 57 fURSL were performed. Preoperative characteristics revealed a mean stone volume of 480.00mm3 (mean Hounsfield Unit- 998). 57.9%(n = 33) of the patients were pre-stented, and a ureteric access sheath was used in 64.9%(n = 37). Integrated-suction was deemed helpful in 94.7%(n = 54) fURSL as reported by the operators. An initial stone free rate (SFR) confirmed by postoperative imaging was achieved in 84.21%(n = 48). Quality parameters of the scope reached a mean Likert score of 4.5, with a "very good" mean evaluation for "scope placement", "visual quality", "irrigation", "deflection", "manoeuvrability", and "weight". "Suction quality" and "overall performance satisfaction" were rated "good". Comparing the Pusen DISS scope with other previously used scopes, overall satisfaction was rated 4.1. When asked if the surgeons would be willing to use the Pusen DISS 7.5Fr scope in the future, all the six surgeons answered positively. CONCLUSION: The DISS 7.5 Pusen ureteroscope displayed good visibility, manoeuvrability and suction quality, with excellent operative results. Further evaluation with larger comparative cohorts will help understand the potential of in-vivo use of integrated suctioning systems for fURSL.

A machine learning approach using stone volume to predict stone-free status at ureteroscopy.

INTRODUCTION: To develop a predictive model incorporating stone volume along with other clinical and radiological factors to predict stone-free (SF) status at ureteroscopy (URS). MATERIAL AND METHODS: Retrospective analysis of patients undergoing URS for kidney stone disease at our institution from 2012 to 2021. SF status was defined as stone fragments < 2 mm at the end of the procedure confirmed endoscopically and no evidence of stone fragments > 2 mm at XR KUB or US KUB at 3 months follow up. We specifically included all non-SF patients to optimise our algorithm for identifying instances with residual stone burden. SF patients were also randomly sampled over the same time period to ensure a more balanced dataset for ML prediction. Stone volumes were measured using preprocedural CT and combined with 19 other clinical and radiological factors. A bagged trees machine learning model with cross-validation was used for this analysis. RESULTS: 330 patients were included (SF: n = 276, not SF: n = 54, mean age 59.5 ± 16.1 years). A fivefold cross validated RUSboosted trees model has an accuracy of 74.5% and AUC of 0.82. The model sensitivity and specificity were 75% and 72.2% respectively. Variable importance analysis identified total stone volume (17.7% of total importance), operation time (14.3%), age (12.9%) and stone composition (10.9%) as important factors in predicting non-SF patients. Single and cumulative stone size which are commonly used in current practice to guide management, only represented 9.4% and 4.7% of total importance, respectively. CONCLUSION: Machine learning can be used to predict patients that will be SF at the time of URS. Total stone volume appears to be more important than stone size in predicting SF status. Our findings could be used to optimise patient counselling and highlight an increasing role of stone volume to guide endourological practice and future guidelines.

First prospective clinical assessment of the ILY® robotic flexible ureteroscopy platform.

PURPOSE: To present the initial prospective clinical assessment of the ILY® robotic ureteroscopy manipulator platform, focusing on its safety and effectiveness. METHODS AND MATERIALS: Data gathered from 31 kidney units which underwent elective robotic flexible ureteroscopy (FURS) for renal stone management utilizing the ILY® robotic system. Patient demographics, stone characteristics, surgical durations, perioperative and post-operative complications, and follow-up parameters were collected. Our primary outcome was evaluating the efficacy and safety of the ILY® robotic ureteroscopy for treating kidney stones. Therefore, we analyzed complication rates, surgical durations, and the stone-free rate during follow-up. RESULTS: Our cohort consisted of 29 patients, presenting with 45 stones with a median volume of 736.22 mm3. The median operation time was 85 min, accompanied by 3 min for robot draping, 3.5 min for robot docking, 48 min of console operation, and lasing time of 36.75 min. Post operative stay for all patients was 1 day, while complications were observed in 9.68% of cases. Notably, all complications were classified as CVD (Clavien-Dindo) class 1 due to pain requiring emergency department visit. The stone-free rate achieved was 93.55%, and none of the patient required reoperation for the treated stone. CONCLUSION: In the first prospective clinical experience of the ILY® robotic FURS, we demonstrated its efficacy and safety. To further investigate its clinical practical value, additional investigations are warranted, including direct comparative analyses with manual flexible ureteroscopy techniques.

Endovascular Treatment for Renal Vein Embolism by a Renal Calculus After Percutaneous Nephrolithotomy.

PURPOSE: This report presents the endovascular strategies adopted to treat a kidney calculus venous embolism after percutaneous nephrolithotomy and the versatility of endovascular techniques to manage even the most unexpected renovascular complications after urological intervention. According to the literature available in PubMed, Cochrane, SciELO, and Science.gov repositories, this is the first case to our knowledge of renal vein calculus embolism as a complication of percutaneous treatment of kidney stones. CASE REPORT: A 62-year-old woman underwent percutaneous nephrolithotomy to treat a left kidney 2.8-cm staghorn calculi. The stone cracked, leaving a residual fragment in the ureteropelvic junction. Abdominal computed tomography revealed a 0.9-mm extrarenal calculus located inside the left retroaortic renal vein. Calculus was captured using a basket catheter system through a 6F 45-cm sheath positioned in the left common femoral vein (CFV) and accessed by dissection to safely conclude the calculus extraction by venous cut down. The patient was asymptomatically discharged 48 hours after the endovascular procedure, under a rivaroxaban anticoagulation regimen, with no symptoms or renal function impairment until the 6 months of follow-up. CONCLUSION: The endovascular strategy proposed in this case was effective for calculus rescue and venous flow restoration. CLINICAL IMPACT: This case reinforces the adaptability of endovascular therapy in an unexpected scenario. A potentially life-threatening extremely rare adverse event following a common urological procedure could be treated with minimally invasive hybrid treatment, preserving renal function and maintaining venous vascular patency. This report may add a discussion of procedures to manage similar events and bring to the literature a possible strategy to solve the problem.

Beyond the kidney: extra-renal manifestations of monogenic nephrolithiasis and their significance.

BACKGROUND: The objective of this study was to explore the frequency of occurrence of extra-renal manifestations associated with monogenic nephrolithiasis. METHODS: A literature review was conducted to identify genes that are monogenic causes of nephrolithiasis. The Online Mendelian Inheritance in Man (OMIM) database was used to identify associated diseases and their properties. Disease phenotypes were ascertained using OMIM clinical synopses and sorted into 24 different phenotype categories as classified in OMIM. Disease phenotypes caused by the same gene were merged into a phenotypic profile of a gene (PPG) such that one PPG encompasses all related disease phenotypes for a specific gene. The total number of PPGs involving each phenotype category was measured, and the median phenotype category was determined. Phenotype categories were classified as overrepresented or underrepresented if the number of PPGs involving them was higher or lower than the median, respectively. Chi-square test was conducted to determine whether the number of PPGs affecting a given category significantly deviated from the median. RESULTS: Fifty-five genes were identified as monogenic causes of nephrolithiasis. A total of six significantly overrepresented and three significantly underrepresented phenotype categories were identified (p < 0.05). Four phenotypic categories (growth, neurological, skeletal, and abdomen/gastrointestinal) are significantly overrepresented after Bonferroni correction for multiple comparisons (p < 0.002). Among all phenotypes, impaired growth is the most common manifestation. CONCLUSION: Recognizing the extra-renal manifestations associated with monogenic causes of kidney stones is critical for earlier diagnosis and optimal care in patients.

Advancements in Uric Acid Stone Detection: Integrating Deep Learning with CT Imaging and Clinical Assessments in the Upper Urinary Tract.

INTRODUCTION: Among upper urinary tract stones, a significant proportion comprises uric acid stones. The aim of this study was to use machine learning techniques to analyze CT scans and blood and urine test data, with the aim of establishing multiple predictive models that can accurately identify uric acid stones. METHODS: We divided 276 patients with upper urinary tract stones into two groups: 48 with uric acid stones and 228 with other types, identified using Fourier-transform infrared spectroscopy. To distinguish the stone types, we created three types of deep learning models and extensively compared their classification performance. RESULTS: Among the three major types of models, considering accuracy, sensitivity, and recall, CLNC-LR, IMG-support vector machine (SVM), and FUS-SVM perform the best. The accuracy and F1 score for the three models were as follows: CLNC-LR (82.14%, 0.7813), IMG-SVM (89.29%, 0.89), and FUS-SVM (29.29%, 0.8818). The area under the curves for classes CLNC-LR, IMG-SVM, and FUS-SVM were 0.97, 0.96, and 0.99, respectively. CONCLUSION: This study shows the feasibility of utilizing deep learning to assess whether urinary tract stones are uric acid stones through CT scans, blood, and urine tests. It can serve as a supplementary tool for traditional stone composition analysis, offering decision support for urologists and enhancing the effectiveness of diagnosis and treatment.

Influence of tract location on the outcomes of endoscopic combined intrarenal surgery: A retrospective analysis of 1000 cases.

OBJECTIVES: This study aimed to investigate the influence of tract location on surgical outcomes in endoscopic combined intrarenal surgery (ECIRS), considering the location of residual stones. METHODS: From January 2015 to December 2021, 1417 consecutive patients underwent ECIRS in three hospitals. After excluding patients with preoperative percutaneous nephrostomy, intended multi-stage procedures, those with a tract in the renal pelvis, and those with multiple tracts, 1000 patients were retrospectively analysed by comparing three groups based on tract location: group 1 (upper calyx), group 2 (middle calyx), and group 3 (lower calyx). A multivariate logistic regression model was implemented to assess whether the tract location independently affected the stone-free status. RESULTS: Patient characteristics were significantly different among the groups in terms of age, stone laterality, presence of calyceal stones, and hydronephrosis. There were no differences in stone-free rate (SFR) among the three groups. Multivariate analysis indicated that the tract location (group 1 or 2 compared with group 3) did not significantly affect the stone-free status (odds ratio = 1.4, 0.9-1.9, p = 0.066). Surgical duration significantly varied among the groups, with the shortest time observed in group 1. Organ injury was observed exclusively in group 1 (1.13%). Residual fragments were predominantly found in the lower calyx, with the calyx associated with the tract being the second most common location. CONCLUSIONS: Tract location does not significantly affect SFR. To improve the SFR, observation of the lower calyx and tract placement is important.

Evaluating the Safety of Retrograde Intrarenal Surgery (RIRS): Intra- and Early Postoperative Complications in Patients Enrolled in the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR).

PURPOSE: To assess the incidence of the most common intra- and early postoperative complications following RIRS in a large series of patients with kidney stones. METHODS: We conducted a retrospective analysis of patients with kidney stones who underwent RIRS across 21 centers from January 2018 to August 2021, as part of the Global Multicenter Flexible Ureteroscopy Outcome (FLEXOR) Registry. RESULTS: Among 6669 patients undergoing RIRS, 4.5% experienced intraoperative pelvicalyceal system bleeding without necessitating blood transfusion. Only 0.1% of patients, required a blood transfusion. The second most frequent intraoperative complication was ureteric injury due to the ureteral access sheath requiring stenting (1.8% of patients). Postoperatively, the most prevalent early complications were fever/infections requiring antibiotics (6.3%), blood transfusions (5.5%), and sepsis necessitating intensive care unit admission (1.3%). In cases of ureteric injury, a notably higher percentage of patients exhibited multiple stones and stone(s) in the lower pole, and these cases were correlated with prolonged lasing and overall surgical time. Hematuria requiring a blood transfusion was associated with an increased prevalence of larger median maximum stone diameters, particularly among patients with stones exceeding 20 mm. Furthermore, these cases exhibited a significant prolongation in surgical time. Sepsis necessitating admission to the intensive care unit was more prevalent among the elderly, concomitant with a significantly larger median maximum stone diameter. CONCLUSIONS: Our analysis showed that RIRS has a good safety profile but bleeding requiring transfusions, ureteric injury, fever, and sepsis are still the most common complications despite advancements in technology.

Comparing Balloon Dilation to Non-Balloon Dilation for Access in Ultrasound-Guided Percutaneous Nephrolithotomy: A Systematic Review and Meta-Analysis.

PURPOSE: This study aims to evaluate the safety and efficacy of ultrasound-guided balloon dilation compared to non-balloon dilation for percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: A systematic review and meta-analysis were conducted by searching PubMed, EMBASE, and the Cochrane Library. Results were filtered using predefined inclusion and exclusion criteria as described and meta-analysis was performed using Review Manager 5.4 software. RESULTS: A total of six studies involving 1189 patients who underwent PCNL were included. The meta-analysis results demonstrated that compared to non-balloon dilation, balloon dilation was associated with reduced haemoglobin drop [mean difference (MD) = -0.26, 95% CI = -0.40 ~ -0.12, P = 0.0002], decreased transfusion rate [odds ratio (OR) = 0.47, 95% CI = 0.24 ~ 0.92, P = 0.03], shorter tract establishment time (MD = -1.30, 95% CI = -1.87 ~ -0.72, P < 0.0001) and shorter operation time (MD = -5.23, 95% CI = -10.19 ~ -0.27, P = 0.04). CONCLUSIONS: Overall, ultrasound-guided balloon dilatation offered several advantages in PCNL procedures. It facilitated faster access establishment, as evidenced by shorter access creation time. Additionally, it reduced the risk of kidney injury by minimizing postoperative haemoglobin drop and decreasing the need for transfusions. Moreover, it enhanced the efficiency of surgery by reducing the operation time. However, it is important to note that the quality of some included studies was subpar, as they did not adequately control for confounding factors that may affect the outcomes. Therefore, further research is necessary to validate and strengthen these findings.

Safety and efficacy of vacuum-assisted mini-percutaneous nephrolithotomy for the treatment of renal stone disease: an analysis of stone free status and postoperative infectious complications.

PURPOSE: Vacuum-assisted mini-percutaneous nephrolithotomy (vmPCNL) is being increasingly adopted due to its faster operating times and lower incidence of postoperative infectious complications (IC), however, studies have been limited by small sample sizes. We hypothesize that vmPCNL is an efficacious treatment for renal stone disease with acceptable stone-free rates (SFR) and low incidence of IC. The objectives of this study were to measure SFR three months after surgery, determine the factors influencing SFR, and determine the rates of postoperative IC after vmPCNL. MATERIALS AND METHODS: Seven hundred and sixty seven patients underwent vmPCNL for the treatment of renal stones > 20 mm at a single institution. Patients underwent postoperative computed tomography at three months to assess SFR. Postoperative fever and SIRS/Sepsis were recorded for individual patients. Multivariate logistics regression was performed to assess predictors of SFR. RESULTS: The SFR was found to be 73.7% at three months. Stone burden (OR 0.39, 95% CI [0.33-0.46]) and age (OR 1.03, 95% CI [1.01-1.04]) emerged as statistically significant predictors of SFR on multivariate analysis. 5.5% of patients experienced postoperative fever, while 2.9% experienced SIRS/Sepsis. CONCLUSIONS: This is the largest continuous cohort of patients to undergo vmPCNL for stone disease and demonstrates that vmPCNL is safe and efficacious, with an SFR of 74% at three months. The incidence of postoperative fever and SIRS/Sepsis is 5.5% and 2.9% respectively. Further randomized studies with large sample sizes are required to ascertain the rates of these complications in comparison to conventional approaches.

High-risk patients for septic shock after percutaneous nephrolithotomy.

PURPOSE: to identify risk factors for urinary septic shock in patients who underwent percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: Data from PCNL procedures performed between January 2009 and February 2020 were retrospectively analyzed. The study included all patients over 18 years old with kidney stones larger than 15 mm who underwent PCNL. Patients who underwent mini-PCNL or combined surgeries, such as ureteroscopy or bilateral procedures, were not included in the study. Logistic regression was conducted to determine the risk factors for urinary septic shock within 30 days post-operation in patients who underwent PCNL. RESULTS: Urinary septic shock was observed in 8 out of the 1,424 patients analyzed (0.56%). The presence of comorbidities, evaluated using the Charlson Comorbidity Index (CCI) (OR 1.46 [CI 95% 1.15-1.86], p=0.01), larger stones (41.0 mm [IQR 30.0-47.5 mm] vs. 24.0 mm [IQR 17.0-35.0 mm], OR 1.03 [CI 95% 1.01-1.06], p=0.04), and a positive preoperative urine culture (OR 8.53 [CI 95% 1.71-42.45], p < 0.01) were shown to significantly increase the risk of postoperative urinary septic shock. Patients with a CCI > 2, larger stones (≥ 35 mm), and a positive preoperative urine culture were at even higher risk of urinary septic shock (OR 15.40 [CI 95% 1.77-134.21], p=0.01). CONCLUSION: Patients with larger stones, positive preoperative urine culture, and a higher CCI are at risk for urinary septic shock after PCNL. These findings are of utmost importance for optimizing the perioperative care of these patients to prevent life-threatening complications.

[Efficacy and safety of mini-track, mini-nephroscopy and mini-ultrasonic probe percutaneous nephrolithotomy for the treatment of 1.5-2.5 cm kidney stones].

OBJECTIVE: To investigate the efficacy and safety of mini-track, mini-nephroscopy and mini-ultrasonic probe percutaneous nephrolithotomy (3mPCNL) for the treatment of 1.5-2.5 cm kidney stones. METHODS: The perioperative data and postoperative follow-up data of a total of 25 patients with about 1.5-2.5 cm kidney stones who underwent 3mPCNL under ultrasound guidance in Peking University People's Hospital from November 2023 to January 2024 were retrospectively analyzed. During the matching period, the 25 patients with 1.5-2.5 cm kidney stones receiving standard percutaneous nephrolithotomy (sPCNL) were matched one-to-one according to the criterion that the absolute difference of the maximum diameter of stones between the two groups was less than 1 mm. The operative time, renal function changes, postoperative stone-free rate, hemoglobin changes, and complication rate of the two treatments were compared, and then the effectiveness and safety of 3mPCNL were preliminarily analyzed. RESULTS: There were no significant differences in mean age, preoperative median creatinine, preoperative mean hemoglobin, preoperative mean hematocrit, median stone maximum diameter, and median stone CT density between the 3mPCNL group and the sPCNL group. The median operation time in the 3mPCNL group was 60.0 (45.0-110.0) min, with no statistical significance compared with the sPCNL group, and all the patients underwent single-channel operations. The mean hemoglobin after operation in the 3mPCNL group was (115.3±15.5) mmol/L, and there was no significant difference between the preoperative group and the sPCNL group, and the mean hemoglobin decreased significantly between the sPCNL group and the sPCNL group [(9.5±2.2) mmol/L vs. (10.1±1.9) mmol/L]. The mean hematocrit after operation was (28.0±5.2)%, and the difference was statistically significant compared with that before operation (t=2.414, P=0.020). The mean hematocrit drop was not statistically signi-ficant compared with the sPCNL group (2.3% vs. 2.7%). The median serum creatinine in the 3mPCNL group was 74.0 (51.0-118.0) µmol/L after operation, and the difference was statistically significant compared with that before operation (Z=-2.980, P=0.005). The stone-free rate in the 3mPCNL group and the sPCNL group was 96.0% and 97.3%, respectively, and the mean hospital stay was (4.3± 1.4) d and (5.5±2.0) d, respectively, with the statistical significance (t=0.192, P=0.025). After the operation, one patient in sPCNL group had massive hemorrhage after the nephrostomy tube was removed, which was improved after selective renal artery embolization. One patient in the 3mPCNL group developed mild perirenal hematoma, which was improved after conservative treatment, and no complications were observed in the other patients. CONCLUSION: 3mPCNL in the treatment of 1.5-2.5 cm kidney stones can achieve an effective rate comparable to sPCNL, and can achieve the ideal stone-free rate in a shorter operative time with a lower rate of surgery-related complications.

Safety and efficacy of a polyherbal formulation from traditional Persian medicine in patients with calcium kidney stones: A randomized, double-blinded clinical trial.

Background: 10%-15% of the world's population suffers from kidney stones. Nearly 50% increase was observed in diagnosing and treating nephrolithiasis in the last decades. Effective medical treatment for the disease is not yet well established. Moreover, there is an increasing global demand to manage diseases using complementary and alternative medicine. This study aimed to formulate and assess the safety and efficacy of a multi-ingredient formulation from traditional Persian medicine (TPM) known as Mofatet powder in patients suffering from calcium kidney stones. Materials and Methods: The aqueous extract of Mofatet powder was prepared, freeze-dried, and formulated as capsules. 26 patients in the drug group and 25 patients in the placebo group used 500 mg capsules of the drug/placebo twice daily for 5 weeks. Ultrasonography/kidney, ureter and bladder imaging, urine analysis, and biochemical parameters were evaluated before and after the intervention. Results: The imaging results showed a 60.73% decrease (P < 0.001) in stone size in the drug group. Moreover, the urinary calcium decreased (P = 0.02) and the urinary magnesium increased (P < 0.001) in the drug group. No remarkable changes were observed in the placebo group in these parameters. No significant effect was observed in aspartate transaminase, alanine transaminase, serum creatinine, and blood urea nitrogen levels in none of the groups. Conclusion: This study suggests that Mofatet powder was effective in reducing calcium kidney stones size with no potential nephro/hepatotoxicity. After confirming these results in larger clinical trials with longer duration, this formulation can be considered a treatment for nephrolithiasis.

Displacement of Lower Pole Stones During Retrograde Intrarenal Surgery Improves Stone-free Status: A Prospective Randomized Controlled Trial.

PURPOSE: Lower pole renal stones are associated with the lowest stone-free status of any location in the urinary tract during retrograde intrarenal surgery. Prior work has suggested displacing lower pole stones to a more accessible part of the kidney to improve stone-free status. We sought to prospectively compare the efficacy of laser lithotripsy in situ vs after displacement during retrograde intrarenal surgery for lower pole stones. MATERIALS AND METHODS: Between July 2017 and May 2022 patients undergoing retrograde intrarenal surgery for lower pole stones were randomized into an in situ or displacement group. Demographics, comorbidities, and operative parameters were documented. Primary outcome was stone-free status, determined by combination of abdominal x-ray and renal ultrasound at 30-day follow-up. Secondary outcomes included operative time, 30-day complications, emergency department visits, and readmissions. RESULTS: A total of 138 patients (69 per group) were enrolled and analyzed. Baseline characteristics were similar between groups. Stone-free status significantly favored the displacement group over the in situ group (95% vs 74%, P = .003, n=62 in each group). Operative time, total laser energy usage, 30-day complications, and 30-day emergency department visits or hospital readmissions were similar between groups. On multivariate analysis only study group allocation was significantly associated with stone-free status (P = .024). CONCLUSIONS: Basket displacement of lower pole stones results in a significantly higher stone-free status compared to in situ lithotripsy. The technique is simple, atraumatic, and requires no additional equipment costs and little additional operative time, making it a practical tool in the treatment of lower pole stones.

Outcomes of Flexible Ureteroscopy vs Extracorporeal Shock Wave Lithotripsy for Renal Stones in Pediatric Patients: A European Association of Urology Urolithiasis Guidelines Systematic Review and Meta-Analysis.

PURPOSE: We sought to determine which treatment between flexible ureteroscopy and shock wave lithotripsy has a better stone-free rate in pediatric patients (<18 years) with renal or proximal ureteric stones (<2 cm). Subanalysis for all outcomes for randomized controlled trials only. MATERIALS AND METHODS: Using PubMed, Web of Science, and the Cochrane database, we identified studies (randomized clinical trials and prospective comparative nonrandomized studies) published until August 2022 reporting surgical outcomes of pediatrics patients undergoing flexible ureteroscopy and shock wave lithotripsy with renal or proximal ureteric stones <2 cm (PROSPERO ID: CRD42022378790). Only randomized controlled trials were considered for meta-analysis. Stone-free rate, operative time, and complications were analyzed. Analysis was performed in R. RESULTS: A total of 6 studies identified, of which 3 were randomized clinical trials and 4 had data on renal stones. A total of 669 patients were analyzed. Mean age ranged from 4.4 to 12.4 years. The shock wave lithotripsy group presented a range of stone-free rate between 21 and 90% while the flexible ureteroscopy group presented a range of stone-free rates between 37% and 97%. Meta-analysis of randomized controlled trials only (n=302) demonstrated significantly higher stone-free rate in flexible ureteroscopy vs shock wave lithotripsy (RR = 1.17, 95% CI: 1.04-1.33, P = 0.01), operative time (mean difference = +16.4 minutes, 95% CI: 7.3-25.5, P < 0.01) and hospital stay (mean difference = +0.25 days, 95% CI: 0.14-0.36, P < 0.001). But no difference in fluoroscopy exposure time (mean difference = -21.0 seconds, 95% CI: -42.6 to 0.56, P = 0.07), Clavien I-II (RR = 1.23, 95% CI: 0.71-2.12, P = 0.45) or Clavien III-V complications (RR = 1.04, 95% CI: 0.32-3.42, P = 0.95). CONCLUSIONS: Flexible ureteroscopy has a significantly higher stone-free rate than shock wave lithotripsy, with no difference in complication rate or fluoroscopy exposure time, and significantly higher operative times and hospital stay. However, the current evidence base for this is weak and further randomized trials are needed.

Characterization of Stone Events in Patients With Type 3 Primary Hyperoxaluria.

PURPOSE: Hallmarks of primary hyperoxaluria type 3 are nephrolithiasis and hyperoxaluria. However, little is known about factors influencing stone formation in this disease. We characterized stone events and examined associations with urine parameters and kidney function in a primary hyperoxaluria type 3 population. MATERIALS AND METHODS: We retrospectively analyzed clinical, and laboratory data of 70 primary hyperoxaluria type 3 patients enrolled in the Rare Kidney Stone Consortium Primary Hyperoxaluria Registry. RESULTS: Kidney stones occurred in 65/70 primary hyperoxaluria type 3 patients (93%). Among the 49 patients with imaging available, the median (IQR) number of stones was 4 (2, 5), with largest stone 7 mm (4, 10) at first imaging. Clinical stone events occurred in 62/70 (89%) with median number of events per patient 3 (2, 6; range 1-49). Age at first stone event was 3 years (0.99, 8.7). Lifetime stone event rate was 0.19 events/year (0.12, 0.38) during follow-up of 10.7 (4.2, 26.3) years. Among 326 total clinical stone events, 139 (42.6%) required surgical intervention. High stone event rates persisted for most patients through the sixth decade of life. Analysis was available for 55 stones: pure calcium oxalate accounted for 69%, with mixed calcium oxalate and phosphate in 22%. Higher calcium oxalate supersaturation was associated with increased lifetime stone event rate after adjusting for age at first event (IRR [95%CI] 1.23 [1.16, 1.32]; P < .001). By the fourth decade, estimated glomerular filtration rate was lower in primary hyperoxaluria type 3 patients than the general population. CONCLUSIONS: Stones impose a lifelong burden on primary hyperoxaluria type 3 patients. Reducing urinary calcium oxalate supersaturation may reduce event frequency and surgical intervention.

Comparison Between Holmium:YAG Laser with MOSES Technology vs Thulium Fiber Laser Lithotripsy in Retrograde Intrarenal Surgery for Kidney Stones in Adults: A Propensity Score-matched Analysis From the FLEXible Ureteroscopy Outcomes Registry.

PURPOSE: We evaluated stone-free rate and complications after flexible ureteroscopy for renal stones, comparing thulium fiber laser and holmium:YAG laser with MOSES technology. MATERIALS AND METHODS: Data from adults who underwent flexible ureteroscopy in 20 centers worldwide were retrospectively reviewed (January 2018-August 2021). Patients with ureteral stones, concomitant bilateral procedures, and combined procedures were excluded. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Stone-free rate was defined as absence of fragments >2 mm on imaging within 3 months after surgery. Multivariable logistic regression analysis was performed to evaluate independent predictors of being stone-free. RESULTS: Of 2,075 included patients, holmium:YAG laser with MOSES technology was used in 508 patients and thulium fiber laser in 1,567 patients. After matching, 284 patients from each group with comparable baseline characteristics were included. Pure dusting was applied in 6.0% of cases in holmium:YAG laser with MOSES technology compared with 26% in thulium fiber laser. There was a higher rate of basket extraction in holmium:YAG laser with MOSES technology (89% vs 43%, P < .001). Total operation time and lasing time were similar. Nine patients had sepsis in thulium fiber laser vs none in holmium:YAG laser with MOSES technology (P = .007). Higher stone-free rate was achieved in thulium fiber laser (85% vs 56%, P < .001). At multivariable analysis, the use of thulium fiber laser and ureteral access sheath ≥8F had significantly higher odds of being stone-free. Lasing time, multiple stones, stone diameter, and use of disposable scopes showed significantly lower odds of being stone-free. CONCLUSIONS: This real-world study favors the use of thulium fiber laser over holmium:YAG laser with MOSES technology in flexible ureteroscopy for renal stones by way of its higher single-stage stone-free rate.

Advances in lasers for the minimally invasive treatment of upper and lower urinary tract conditions: a systematic review.

PURPOSE: Technological advancements in laser lithotripsy are expanding into numerous fields of urology, like ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), and benign and malignant soft-tissue treatments. Since the amount of research regarding lasers in urology has grown exponentially, we present a systematic review of the most recent and relevant advances encompassing all lasers used in urological endoscopic treatment. METHODS: We performed a literature search using PubMed (May 2023) to obtain information about lasers for urological purposes. We included only recent data from published articles between 2021 and 2023 or articles ahead of print. RESULTS: Lasers are widely used in lithotripsy for ureteric, renal, and bladder stones, benign prostate surgery, and bladder and upper tract tumor ablation. While the holmium (Ho:YAG) laser is still predominant, there seems to be more emphasis on pulse modulation and newer lasers such as thulium fiber laser (TFL) and pulsed Tm:YAG laser. CONCLUSION: The use of lasers and related technological innovations have shown increasing versatility, and over time have proven to be invaluable in the management of stone lithotripsy, treatment of benign and malignant prostate diseases, and urothelial tumors. Laser endoscopic treatment is heavily based on technological nuances, and it is essential to know at least the basics of these technologies. Ultimately the choice of laser used depends on its availability, cost, surgeon experience and expertise.

Ureteroscopy and lasertripsy with pop dusting using high power holmium laser for large urinary stones > 15 mm: 6.5-year prospective outcomes from a high-volume stone center.

INTRODUCTION: Ureteroscopy and stone lasertripsy (URSL) is a recognized technique for treatment of urinary tract stones. Holmium:Yag laser has been successfully used for this purpose for the last two decades. More lately, pulse modulation with Moses technology and high power lasers have been introduced with the result of faster and more efficient stone lasertripsy. Pop dusting is a two-stage combined treatment using a long pulse Ho:YAG laser, initially in contact mode with the stone 'dusting' (0.2-0.5 J/40-50 Hz) followed by non-contact mode 'pop-dusting' (0.5-0.7 J/20-50 Hz). We wanted to look at the outcomes of lasertripsy for renal and ureteric stones using a high-power laser machine. METHODS: Over a period of 6.5 years (January 2016-May 2022), we prospectively collected data for patients undergoing URSL for stones larger than 15 mm treated using high power Ho:YAG laser (60W Moses or 100W laser). Patient parameters, stone demographics and outcomes of URSL were analyzed. RESULTS: A total of 201 patients, underwent URSL for large urinary stones. In 136 patients (61.6%) stones were multiple and the mean single and cumulative stone size was 18 mm and 22.4 mm respectively. A pre- and post-operative stent was placed in 92 (41.4%) and 169 (76%) respectively. The initial and final stone free rate (SFR) were 84.5% and 94% respectively and 10% patients underwent additional procedure to achieve stone free status. 7 (3.9%) complications were recorded, all related to UTI/sepsis, with 6 Clavien II and 1 Clavien IVa complication. CONCLUSION: Dusting and pop-dusting has shown to be successful and safe with the ability to treat large, bilateral or multiple stones with low retreatment and complication rates.