Sodium-glucose cotranspor ter 2 (SGLT2) inhibitors in nephrolithiasis: should we "gliflozin" patients with kidney stone disease? / Inibidores de cotransportadores sódio-glicose-2 (SGLT2) na nefrolitíase - devemos "gliflozinar" os litiásicos?

ABSTRACT The prevalence of nephrolithiasis is increasing worldwide. Despite advances in understanding the pathogenesis of lithiasis, few studies have demonstrated that specific clinical interventions reduce the recurrence of nephrolithiasis. The aim of this review is to analyze the current data and potential effects of iSGLT2 in lithogenesis and try to answer the question: Should we also "gliflozin" our patients with kidney stone disease?

RESUMO A prevalência da nefrolitíase está aumentando em todo o mundo. Apesar dos avanços na compreensão da patogênese da doença litiásica, poucos estudos demonstraram que intervenções clínicas específicas diminuem a recorrência da nefrolitíase. O objetivo desta revisão é analisar os dados atuais e efeitos potenciais dos iSGLT2 na doença litiásica e tentar responder à pergunta: devemos também "gliflozinar" os litiásicos?

Efficacy of mini-endoscopic combined intrarenal surgery for pediatric kidney calculi: a single center retrospective study.

Management of large pediatric kidney calculi (PKC) is challenging. This study aimed to evaluate the efficacy and safety of miniature endoscopic combined intrarenal surgery (mini-ECIRS) for PKC. We retrospectively analyzed mini-ECIRS in 16 pediatric patients undergoing kidney stone treatment between November 2014 and October 2023 to determine its safety, efficacy, and associated outcomes. The median age was 50.50 (interquartile range: 36.75, 84.75) months, and the mean stone size was 21.63 ± 11.65 mm. The stone-free rate was 81.25%. The median decrease in hemoglobin level on the day after surgery was 1.10 (0.80, 1.55), and no patient required a blood transfusion. The median number of general anesthesia procedures was 2.00 (2.00, 2.00). Postoperative complications included fever in two patients and difficulty in removing the ureteral stent in one patient. In this cohort, five patients underwent pre-stenting under general anesthesia before mini-ECIRS. Age was significantly lower in the pre-stenting group than in the non-pre-stenting (P < 0.01); however, there were no significant differences in operative time, stone-free rate, total number of general anesthesia procedures, hemoglobin loss, or postoperative hospital stay between the groups. Mini-ECIRS was found to be a safe and efficient treatment method with a high stone removal rate in pediatric patients.

[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.

Can Machine Learning Correctly Predict Outcomes of Flexible Ureteroscopy with Laser Lithotripsy for Kidney Stone Disease? Results from a Large Endourology University Centre.

Background and objective: The integration of machine learning (ML) in health care has garnered significant attention because of its unprecedented opportunities to enhance patient care and outcomes. In this study, we trained ML algorithms for automated prediction of outcomes of ureteroscopic laser lithotripsy (URSL) on the basis of preoperative characteristics. Methods: Data were retrieved for patients treated with ureteroscopy for urolithiasis by a single experienced surgeon over a 7-yr period. Sixteen ML classification algorithms were trained to investigate correlation between preoperative characteristics and postoperative outcomes. The outcomes assessed were primary stone-free status (SFS, defined as the presence of only stone fragments <2 mm on endoscopic visualisation and at 3-mo imaging) and postoperative complications. An ensemble model was constructed from the best-performing algorithms for prediction of complications and for prediction of SFS. Simultaneous prediction of postoperative characteristics was then investigated using a multitask neural network, and explainable artificial intelligence (AI) was used to demonstrate the predictive power of the best models. Key findings and limitations: An ensemble ML model achieved accuracy of 93% and precision of 87% for prediction of SFS. Complications were mainly associated with a preoperative positive urine culture (1.44). Logistic regression revealed that SFS was impacted by the total stone burden (0.34), the presence of a preoperative stent (0.106), a positive preoperative urine culture (0.14), and stone location (0.09). Explainable AI results emphasised the key features and their contributions to the output. Conclusions and clinical implications: Technological advances are helping urologists to overcome the classic limits of ureteroscopy, namely stone size and the risk of complications. ML represents an excellent aid for correct prediction of outcomes after training on pre-existing data sets. Our ML model achieved accuracy of >90% for prediction of SFS and complications, and represents a basis for the development of an accessible predictive model for endourologists and patients in the URSL setting. Patient summary: We tested the ability of artificial intelligence to predict treatment outcomes for patients with kidney stones. We trained 16 different machine learning tools with data before surgery, such as patient age and the stone characteristics. Our final model was >90% accurate in predicting stone-free status after surgery and the occurrence of complications.

Artificial Intelligence in Urology: Application of a Machine Learning Model to Predict the Risk of Urolithiasis in a General Population.

This research presents our application of artificial intelligence (AI) in predicting urolithiasis risk. Previous applications, including AI for stone disease, have focused on stone composition and aiding diagnostic imaging. AI applications centered around patient-specific characteristics, lifestyle considerations, and diet have been limited. Our study comprised a robust sample size of 976 Chilean participants, with meticulously analyzed demographic, lifestyle, and health data through a comprehensive questionnaire. We developed a predictive model using various classifiers, including logistic regression, decision trees, random forests, and extra trees, reaching high accuracy (88%) in identifying individuals at risk of kidney stone formation. Key protective factors highlighted by the algorithm include the pivotal role of hydration, physical activity, and dietary patterns that played a crucial role, emphasizing the protective nature of higher fruit and vegetable intake, balanced dairy consumption, and the nuanced impact of specific protein sources on kidney stone risk. In contrast, identified risk factors encompassed gender disparities with males found to be 2.31 times more likely to develop kidney stones than females. Thirst and self-perceived dark urine color emerged as strong predictors, with a significant increase in the likelihood of stone formation. The development of predictive tools with AI, in urolithiasis management signifies a paradigm shift toward more precise and personalized health care. The algorithm's ability to process extensive datasets, including dietary habits, heralds a new era of data-driven medical practice. This research underscores the transformative impact of AI in medical diagnostics and prevention, paving the way for a future where health care interventions are not only more effective but also tailored to individual patient needs. In this case, AI is an important tool that can help patients stay healthy, prevent diseases, and make informed decisions about their overall well-being.

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.

Could Use of a Flexible and Navigable Suction Ureteral Access Sheath Be a Potential Game-changer in Retrograde Intrarenal Surgery? Outcomes at 30 Days from a Large, Prospective, Multicenter, Real-world Study by the European Association of Urology Urolithiasis Section.

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the stone-free status (SFS) rate and complications after flexible ureteroscopy (fURS) for treatment of renal stones using a flexible and navigable suction (FANS) ureteral access sheath. METHODS: Data for adults undergoing fURS in 25 centers worldwide were prospectively collected (August 2023 to January 2024). Exclusion criteria were abnormal renal anatomy and ureteral stones. All patients had computed tomography scans before and within 30 d after fURS with a FANS ureteral access sheath. SFS was defined as follows: grade A, zero fragments; grade B, a single fragment ≤2 mm; grade C, a single fragment 2.1-4 mm; and grade D, single/multiple fragments >4 mm. Data for continuous variables are presented as the median and interquartile range (IQR). Multivariable logistic regression was performed to evaluate predictors of grade A SFS. KEY FINDINGS AND LIMITATIONS: The study enrolled 394 patients (59.1% male) with a median age of 49 yr (IQR 36-61). The median stone volume was 1260 mm3 (IQR 706-1800). Thulium fiber laser (TFL) was used in 45.9% of cases and holmium laser in the rest. The median lasing time was 18 min (IQR 11-28) and the median operative time was 49 min (IQR 37-70). One patient required a blood transfusion and 3.3% of patients had low-grade fever. No patient developed sepsis. Low-grade ureteral injury occurred in eight patients (2%). The grade A SFS rate was 57.4% and the grade A + B SFS rate was 97.2%, while 2.8% of patients had grade C or D SFS. Eleven patients underwent repeat fURS. Multivariable analysis revealed that a stone volume of 1501-3000 mm3 (odds ratio 0.50) and of >3000 mm3 (odds ratio 0.29) were significantly associated with lower probability of grade A SFS, while TFL use was associated with higher SFS probability (odds ratio 1.83). Limitations include the lack of a comparative group. CONCLUSIONS AND CLINICAL IMPLICATIONS: fURS using a FANS ureteral access sheath resulted in a high SFS rate with negligible serious adverse event and reintervention rates. PATIENT SUMMARY: We looked at 30-day results for patients undergoing telescopic laser treatment for kidney stones using a special type of vacuum-assisted sheath to remove stone fragments. We found a high stone-free rate with minimal complications.

Is ureteroscopy and active stone treatment safe and effective in octogenarians? A review of current literature.

Background: With the aging of our patient population, and the increasing incidence of kidney stone disease in the elderly, active stone treatment is becoming more common. In this review of current literature, we aim to assess safety and efficacy of ureteroscopy (URS) as primary treatment for urolithiasis in the octogenarians. Materials and methods: A scoping review of literature according to the PRISMA guidelines was performed, using the relevant search terms. Original articles were screened and included. A narrative review of the studies is provided, with emphasis on outcomes of URS in the elderly. Results: 10 studies were included in the analysis. URS performed in the elderly population showed a good safety and efficacy, with stone-free rates (SFR) comparable to the general population. URS specific complication rates seems to be comparable to the other age groups, with postoperative events mostly related to anaesthesia and pre-existing medical conditions. The overall complication rate was still low, with a slightly prolonged hospital stay. Predictors for SFR were age, severe comorbidities and stone burden. Conclusion: URS for stone treatment in the elderly population is safe and effective, with comparable surgical outcomes to that of the general population. As comorbidities play an important role in the fitness for surgery and overall survival, risks and benefit of active stone treatment should be carefully balanced in this group.

Supine tubeless upper pole PCNL under spinal anaesthesia: Safety, feasibility and outcomes from a tertiary endourology centre.

Objective: Supine Percutaneous Nephrolithotomy (PCNL) is being taken up by many urologists in recent times, but there is a tendency to shift to prone PCNL for upper pole puncture. We analyzed the safety, feasibility and outcomes of upper pole access in Supine Percutaneous Nephrolithotomy (sPCNL). Materials and methods: A retrospective review of all patients undergoing sPCNL at a tertiary care center was done from January 2021 to December 2022. Data collection was done from the maintained imaging, laboratory and hospital records. All cases with complete data on upper pole access were included. Data analysis was done with Xlstat2021. Results: 50 patients with upper pole access were included (64%, 32 with single access and 36%, 18 with multiple accesses). The mean stone size was 23.88 ± 9.99, mean HU was 1093 ± 232.83, and the mean operative duration was 67.92 ± 34.62. Stone clearance rate was 98.82%, with all procedures performed tubeless.The mean haemoglobin drop was 0.75 ± 0.42 gm/dl with 2 (4%) patients needing a blood transfusion. The overall complication rate was 22% with only 1 Clavien Dindo III complication (1 pleural injury and hydrothorax needing USS guided aspiration) and others being Clavien Dindo I/II complications. Conclusion: Supine PCNL is a feasible and safe approach for upper pole access. While the procedure can be done tubeless, these procedures must be done in experienced endourology units.

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.

Prone vs supine percutaneous nephrolithotomy: does position affect renal pelvic pressures?

The purpose of this study was to measure and compare renal pelvic pressure (RPP) between prone and supine percutaneous nephrolithotomy (PCNL) in a benchtop model. Six identical silicone kidney models were placed into anatomically correct prone or supine torsos constructed from patient CT scans in the corresponding positions. A 30-Fr renal access sheath was placed in either the upper, middle, or lower pole calyx for both prone and supine positions. Two 9-mm BegoStones were placed in the respective calyx and RPPs were measured at baseline, irrigating with a rigid nephroscope, and irrigating with a flexible nephroscope. Five trials were conducted for each access in both prone and supine positions. The average baseline RPP in the prone position was significantly higher than the supine position (9.1 vs 2.7 mmHg; p < 0.001). Similarly, the average RPP in prone was significantly higher than supine when using both the rigid and flexible nephroscopes. When comparing RPPs for upper, middle, and lower pole access sites, there was no significant difference in pressures in either prone or supine positions (p > 0.05 for all). Overall, when combining all pressures at baseline and with irrigation, with all access sites and types of scopes, the mean RPP was significantly higher in the prone position compared to the supine position (14.0 vs 3.2 mmHg; p < 0.001). RPPs were significantly higher in the prone position compared to the supine position in all conditions tested. These differences in RPPs between prone and supine PCNL could in part explain the different clinical outcomes, including postoperative fever and stone-free rates.

Multivitamins co-intake can reduce the prevalence of kidney stones: a large-scale cross-sectional study.

BACKGROUND: This research aimed to explore the association between changes in the intake of common individual vitamins and combinations of vitamins and the prevalence of kidney calculi. METHODS: We used data from NHANES to investigate the association between nine common vitamins and kidney stone prevalence. Participants were clustered into several vitamin exposure patterns using an unsupervised K-means clustering method. We used logistic regression models and restrictive cubic spline curves to explore the influence of vitamins. RESULTS: The regression model exposed that compared to lower intake, high intake of vitamin B6 [Q4: OR (95% CI) = 0.76 (0.62, 0.93)], vitamin C [Q4: OR (95% CI) = 0.73 (0.59, 0.90)] and vitamin D [Q4: OR (95% CI) = 0.77 (0.64, 0.94)] individually exerted protective effects against the prevalence of kidney stones. Furthermore, the restrictive cubic spline analysis showed that the protective effect against the prevalence of kidney stones is enhanced as the take of vitamin B6 and vitamin D increased. Moreover, with the increase in vitamin C intake, its protective effect may turn into a risk factor. Regarding mixed exposure, Cluster 4 exhibited a significant protective effect against kidney stones compared with Cluster 1 [Model 3: OR (95% CI) = 0.79 (0.64, 0.98)]. CONCLUSIONS: Our research revealed that high levels of vitamin B6 and vitamin D intake were linked to a lower prevalence of kidney stone. With the gradual increase intake of vitamin C, the prevalence of kidney calculi decreased first and then increased. In addition, the co-exposure of nine vitamins is a protective factor for kidney stone disease.

Retrograde intrarenal surgery using the ILY robotic flexible ureteroscope: a single centre experience.

Introduction: The ILY robotic flexible ureteroscope has been introduced in order to improve intraoperative ergonomics, reduce operator distance from radiation and shorten the learning curve. In this study we aimed to assess the clinical performance and feasibility of the ILY robot during retrograde intrarenal surgery (RIRS) and combined endoscopic procedures (miniECIRS). Material and methods: The RIRS procedures were performed using the ILY robotic arm in 57 adult patients (46 RIRS and 11 miniECIRS) from 2022 to 2023. All procedures were performed in the supine position. Pre-stenting was not the standard of care. Results: Turning on and calibration of the device took approximately 100 s. Average draping time was 93 s using original ILY drapes and 47 s using classic drapes designed for C-arm covering. Mean docking time was 73 s in procedures with ureteral access sheath (UAS) and 61 s in procedures without it. The undocking took less than 60 s in every case. Average procedure time was 63 min for RIRS and 55 min for miniECIRS. Endoscopically proven stone-free rate was achieved in 37 (80.4%) RIRS and 10 (90.9%) miniECIRS patients. A total of 17 (36.9%) RIRS and 8 (72.7%) miniECIRS procedures required conversion in order to perform basketing and stone fragments retrieval/transposition. Conclusions: The use of ILY robot during endourological procedures is feasible and urologists that are familiar with the device controller do not require extensive training. The time needed for device draping, docking and undocking was approximately 4 minutes. Moreover, use of the robot resulted in satisfactory stone-free rates.

Regional versus general anaesthesia in percutaneous nephrolithotomy: a systematic review and meta-analysis.

Introduction: Several studies have compared the safety and effectiveness of general and regional anaesthesia in percutaneous nephrolithotomy (PCNL). This study aimed to compare the perioperative and postoperative outcomes of general anaesthesia and regional anaesthesia for patients undergoing PCNL. Material and methods: For relevant articles, three electronic databases, including PubMed, Scopus, and Web of Science, were searched from their inception until March 2023. A meta-analysis has been reported in line with PRISMA 2020 and AMSTAR Guidelines. The risk ratio (RR) and mean difference (MD) were applied for the comparison of dichotomous and continuous variables with 95% confidence intervals (CI). Results: The final cohort analysis, comprised 3871 cases of PCNL, (2154 regional anaesthesia and 1717 general anaesthesia). Compared to general anaesthesia, the regional anaesthesia group had a significantly shorter length of stay (MD = -0.34 days, 95% CI -0.56 to -0.12, p = 0.002), lower postoperative nausea and vomiting rates (RR = 0.16, 95% CI 0.03 to 0.80, p = 0.026), lower complications grade III-V rates (RR = 0.68, 95% CI 0.53 to 0.88, p = 0.004), and lower postoperative visual analogue pain score (VAS) at 1 hour (MD = -3.5, 95% CI -4.1 to -2.9, p <0.001). There were no significant differences in other outcomes between the two groups. Conclusions: Our results show that PCNL under regional anaesthesia is safe and feasible, with comparable results to those done under general anaesthesia. While patient selection is important, counselling and decision-making for these procedures must go hand in hand to achieve the best clinical outcome.

Extracorporeal shock wave lithotripsy, ureterolithotripsy, and percutaneous nephrolithotripsy challenges in managing spinal cord neuropathy patients. Lessons learned from a scoping review.

Introduction: We aim to review the outcomes of shock wave lithotripsy (SWL), ureteroscopy, and percutaneous nephrolithotripsy (PCNL) for renal and ureteral stones in spinal cord neuropathy patients (SNP). Material and methods: A literature search was performed on 8th March 2023 using PubMed, EMBASE, and Google Scholar with no date limit. Preclinical/animal studies, reviews, letters to the editor, case reports, and meeting abstracts were excluded. Only English papers were accepted. Results: Thirty-five articles were accepted. Five studies focused on SWL, 17 on PCNL, and 6 on ureteroscopy. The remaining articles employed more than one procedure. Stone composition has shifted from struvite to the more common calcium phosphate. SWL showed a very poor stone-free rate (SFR) likely due to challenges in patient positioning, stone visualization, localization, and inability to pass fragments spontaneously. Flexible ureteroscopy and PCNL were associated with a high incidence of infectious complications, long hospital stays, high blood transfusion rate, and intensive care admissions. There were also cases of death. Both procedures were challenging due to genitourinary reconstruction, scoliosis and kyphosis, rib-cage deformity, lower limb contractures, and severe comorbidity which also affected anesthesia. SFR was lower than in non-neurological patients. Conclusions: SWL, ureterolithotripsy, and PCNL should be considered challenging procedures in SNP due to positioning issues, an increased risk of intra and peri-operative morbidity, and even mortality. Computed tomography should be recommended to assess residual fragments as it becomes imperative to minimize a re-intervention in SNP who should be preferably treated in referral centers.

First worldwide report on safety and efficacy of using small 7.5 Fr scope for pediatric ureteroscopy: prospective pilot series from Europe.

Introduction: Although pediatric urolithiasis remains relatively uncommon, its global prevalence is on the rise. Technological advances have led to miniaturization of instruments especially in the form of single use scopes. As the evidence on the use of small single use ureteroscopes in children is scarce, we have conducted a pilot two-center study to analyze the outcomes of pediatric patients treated with the Pusen 7.5 Fr single use scopes at our institutions. Material and methods: This study included consecutive pediatric patients with urinary stones treated with the small Pusen 7.5 Fr single use ureteroscope. The study was conducted at two large European tertiary endourology centers that specialize in pediatric kidney stone management. Patient data and outcomes were prospectively collected, and analysis was performed regarding patient demographics, stone parameters, as well as stone free rate (SFR), operating time, and complications. Results: In this pilot study, 26 patients were included with a median age of 12 years (7.0-16.0) and a male to female ratio of 14:12. The mean cumulative stone size was 15.15 mm (SD ±11.1) and multiple stones were present in 9 (34.6%) patients. Pre-operative stent, access sheath and post-operative stent usage was done in 12 (46.2%), 23 (88.5%) and 13 (50%) patients respectively. The median operative time was 47 minutes (IQR: 40.0-63.8). Following the initial procedure 24 (92.3%) patients were stone free, while no intra or postoperative complications were observed. Conclusions: Our study demonstrates that the use of the small 7.5 single use ureteroscope is safe and efficient for the treatment of urinary stones in pediatric patients with high stone-free rates and no complications noted in our series. While this might become a standard of care in future, to confirm and validate our findings further studies with larger cohorts are warranted.

Percutaneous Nephrolithotomy for De Novo Urolithiasis After Kidney Transplantation: A Systematic Review of the Literature.

Introduction and Objective: Renal transplantation is the treatment for end-stage renal disease that offers better quality of life and survival. Among the possible complications that might affect allografts, urolithiasis might have severe consequences, causing acute kidney injury (AKI) or septic events in immunocompromised patients. Allograft stones might be treated with percutaneous nephrolithotomy (PCNL). The aim of this Cochrane style review was to assess the safety and efficacy of PCNL in patients with renal transplant. Methods: A comprehensive search in the literature was performed including articles between July 1982 and June 2023, with only English original articles selected for this review. Results: The final review encompassed nine articles (108 patients). The mean age was 46.4 ± 8.7 years, with a male:female ratio of 54:44. The average time from transplantation to urolithiasis onset was 47.54 ± 23.9 months. Predominant symptoms upon presentation were AKI (32.3%), followed by urinary tract infection and fever (24.2%), and oliguria (12.9%). The mean stone size was 20.1 ± 7.3 mm, with stones located in the calices or pelvis (41%), ureteropelvic junction (23.1%), or proximal ureter (28.2%). PCNL (22F-30F) was more frequently performed than mini-PCNLs (16F-20F) (52.4% vs 47.6%). Puncture was guided by ultrasound (42.9%), fluoroscopy (14.3%), or both (42.9%). The stone-free rate (SFR) and complication rates were 92.95% (range: 77%-100%) and 5.5%, respectively, with only one major complication reported. Postoperatively, a ureteral stent and nephrostomy were commonly placed in 47%, with four patients needing a second look PCNL. During an average follow-up of 32.5 months, the recurrence rate was 3.7% (4/108), and the mean creatinine level was 1.37 ± 0.28 mg/dL. Conclusions: PCNL remains a safe and effective option in de novo allograft urolithiasis, allowing to treat large stones in one-step surgery. A good SFR is achieved with a low risk of minor complications. These patients should be treated in an endourology center in conjunction with the renal or transplant team.

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.

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.

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.