Stone Episodes Research Articles

Kidney Stones as Minerals: How Methods from Geology Could Inform Urolithiasis Treatment

Despite the recent advances in minimally invasive surgery, kidney stones still pose a significant clinical challenge due to their high recurrence rate of 50% in 5–10 years after the first stone episode. Using the methods of geosciences and biology, the GeoBioMed approach treats kidney stones as biogenic minerals, offering a novel perspective on their formation and dissolution processes. In this review, we discuss kidney stones’ structural and mechanical properties as emerging biomarkers of urolithiasis, emphasizing the importance of a comprehensive stone analysis in developing personalized treatment strategies. By focusing on unexplored properties like crystalline architecture, porosity, permeability, cleavage, and fracture, alongside the conventionally used composition and morphology, we show how these stone characteristics influence the treatment efficacy and the disease recurrence. This review also highlights the potential of advanced imaging techniques to uncover novel biomarkers, contributing to a deeper understanding of stone pathogenesis. We discuss how the interdisciplinary collaboration within the GeoBioMed approach aims to enhance the diagnostic accuracy, improve the treatment outcomes, and reduce the recurrence of urolithiasis.

Comparative study between silodosin, tamsulosin, silodosin plus tadalafil, and tamsulosin plus tadalafil as a medical expulsive therapy for lower ureteral stones: a prospective randomized trial.

To examine the safety and efficiency of a single-drug therapy with silodosin or tamsulosin versus combined therapy with silodosin plus tadalafil and tamsulosin plus tadalafil as a medical expulsive therapy (MET) for lower ureteral stones. This research was a prospective randomized clinical trial carried out at Fayoum University Hospital, Egypt, over one year. Patients with lower ureteral stones (5-10mm) were randomly allocated into one of four treatment groups. Group A received silodosin 8mg per day; Group B received tamsulosin 0.4mg per day; Group C received silodosin 8mg plus tadalafil 5mg daily, and Group D received tamsulosin 0.4mg plus tadalafil 5mg daily. Treatment was prescribed for up to 4weeks. The study outcomes were the stone expulsion rate, stone expulsion time, the amount of analgesics used, the frequency of pain episodes, hospital visits, and any treatment-related adverse effects. One hundred eighty patients who fulfilled the inclusion criteria completed the study. Group C had a significantly elevated stone expulsion rate (91.1%) compared to Group A (57.8%) and Group B (71.1%) [P = 0.015, P < 0.001, respectively]. Group D had a significantly elevated stone expulsion rate (86.7%) compared to Group B (57.8%) [P = 0.002] and higher than Group A (71.1%). Group C and Group D had significantly less stone expulsion time, analgesic needs, and episodes of renal colic, and fewer hospital visits than Group A and Group B. No significant differences were found in adverse effects like orthostatic hypotension, dizziness, backache, headache, myalgia, and nausea between the patient groups. Combining silodosin with tadalafil and tamsulosin with tadalafil was more efficient as MET for lower ureteric stones than a single treatment with silodosin or tamsulosin.

A giant parathyroid adenoma: a case report

BackgroundPrimary hyperparathyroidism is an endocrine disease and a common cause of nonmalignant hypercalcemia, often discovered incidentally in asymptomatic patients. The case reported herein illustrates that significant hormonal imbalances can present with unexpectedly mild clinical manifestations.Case presentationWe describe a 47-year-old Caucasian male with two episodes of kidney stones and otherwise no symptoms of severe hypercalcemia. In our case, fasting emerged as a potential risk factor for the development of renal stones. The diagnosis was primary hyperparathyroidism. The intervention consisted of preoperative fluids and cinacalcet while awaiting surgery. Despite initial stability, the patient experienced a subsequent increase in ionized calcium and parathyroid hormone levels, becoming symptomatic with fatigue, tremors, and heart palpitations. This progression led to a diagnosis of a hypercalcemic crisis, and the plan was accelerated. An acute parathyroid scintigraphy and an ultrasound was performed and revealed a giant intrathoracic parathyroid adenoma. After surgical removal of the adenoma, he developed hungry bones and biochemical remission. The patient has received three extracorporeal shock wave lithotripsy treatments for a stone in the upper left kidney, but as of a computed tomography scan on 9 February 2024, the stone remains unchanged. Owing to the stone’s resistance to extracorporeal shock wave lithotripsy and the absence of symptoms, no further treatment is planned. Endoscopic laser treatment (retrograde intrarenal surgery) is an option, but for now, the situation will be monitored.ConclusionThis case report underscores that extremely elevated levels of calcium and parathyroid hormone along with a rare giant parathyroid adenoma may not necessarily present with symptoms indicative of a calcium crisis. Additionally, management of such rare giant parathyroid adenomas requires careful monitoring and a tailored approach to address potential postsurgical complications such as hungry bone syndrome.

Development and Implementation of an Evidence-Based Electronic Request Bundle for Metabolic Screening in Patients With Urinary Tract Calculi.

Introduction Kidney stonedisease is a global health issue, with a well-known high recurrence rate after a first stone episode. Metabolic screening is a cost-effective tool for identifying patients at risk of recurrence due to a secondary disease. Our study aimed to assess compliance in a District General Hospital (DGH) and lay out a framework for the implementation of an electronic request bundle to improve screening levels in line with National Institute for Health and Care Excellence (NICE) guidelines. Methods A retrospective, cross-sectional study was conducted on 67 eligible patients, presenting with nephrolithiasis between May 2023 and July 2023. The percentage undergoing metabolic screening on admission was recorded and compared against previous Trust data. Clinical staff were surveyed to develop a streamlined electronic bundle, which was thenimplemented across the Trust collaboratively with Unity EPR engineers and senior clinical andnon-clinical management. Results Thirty (47.8%)eligible patients had serum calcium levels measured on admission, and 25 (37.3%) patients had serum urate measured - similar screening levels to that collected during previous audits in the same Trust. Of the 30 surveyed staff, 12 (40.0%) reported they would routinely check serum urate and 15 (50.0%) serum calcium in renal stone presentations. In total, eightmonths of stakeholder meetings were required to effectively develop and deploy a new electronic requesting bundle, aiming to increase metabolic screening levels at the Trust. Discussion Adherence to NICE guidelines in renal stone patients at this DGH was significantly below the recommended standards of care. Identifying intervention points, surveying staff, and working with key stakeholders allowed for the integration of a metabolic screening tool. This study provides an effective framework for the development and sustainable implementation of an electronic requesting bundle, which can be modeled healthcare-wide.

Factors affecting radiation exposure in patients undergoing endoscopic treatment for urolithiasis.

Imaging techniques, such as computed tomography (CT) and fluoroscopy, are essential for the diagnosis and treatment of urolithiasis. There is increasing concern regarding the cumulative radiation dose associated with medical imaging and its adverse effects. This study aimed to assess radiation exposure in patients undergoing endoscopic management of urolithiasis and to identify factors associated with increased exposure.A retrospective analysis of all consecutive symptomatic urolithiasis cases who underwent endoscopic surgery over a two-year period at a tertiary referral center was performed. The cumulative radiation dose was recorded per stone episode, and the effective dose (ED) then calculated. Multivariable regression analysis was performed to determine the association between ED and patient, stone, and procedural characteristics.Between January 2020 and December 2021, 250 patients underwent endoscopic intervention for urolithiasis; 71% (n = 178) were male with a median age of 48 years (IQR 35-59). The median stone size was 6mm (IQR, 5-8mm) and the median stone volume was 110 mm3 (IQR, 60-206 mm3). Most stones were located in the distal ureter (46%, n = 114). The median ED received per stone episode was 3.99 mSv (IQR 2.9-7 mSv). On multivariable analysis, BMI, number of CT scans performed, CT protocol used, and repeat procedures strongly predicted increased radiation dose (p < 0.01).It is important for urologists to consider the cumulative radiation dosage in patients with urolithiasis. Strategies to minimize exposure, such as avoiding re-imaging, low-dose CTs, and collimation of the region of interest with judicious magnification, should be considered during treatment.

Integrated Care in a Large Public System Improves Simple Kidney Stone Management.

In the Los Angeles County Department of Health Services-the second largest public health care system in the United States-clinical integration allows specialists and primary care providers to collaboratively provide specialty care. We used time-driven activity-based costing to compare patient burden and cost of kidney stone diagnosis, workup, and management with and without clinical integration. We interviewed and observed teams of physicians and staff to understand workflow practices and personnel, space, material, and device requirements for stone care in the 2 models. We created process maps that outline the entire arc of care and used time-driven activity-based costing to calculate the all-inclusive costs of kidney stone diagnosis, workup, and scheduling for surgical treatment. The total cost of kidney stone treatment per stone episode in the integrated pathway was $499.04, compared with $699.81 in the traditional, nonintegrated pathway, a difference of 29%. The number of steps needed to arrive at operating room scheduling was 11 with integration and 14 without it. Clinical integration resulted in more efficient and cost-effective care from patient, provider, and health system perspectives. Integrated care may improve access to specialty care and increase the value of care and reduce treatment burden on patients.

Challenges in diagnosis and treatment of cystinuria patients with Urolithiasis: multicenter patient centered study.

Cystinuria represents a rare cause of urolithiasis, accounting for 1% of all cases. However, it poses unique challenges in diagnosis and management. This study aimed to examine the challenges of managing cystine stones from the perspective of cystinuria patients. Following ethical approval, we reviewed the medical records of cystine stone patients treated at four tertiary centers from 2016 to 2021 and surveyed them on their perceptions of cystinuria. It included questions about demographic characteristics, herbal treatments, pain management, online engagement, disease outcomes, and cystinuria-related fears. The study included 28 adults with cystinuria nephrolithiasis, with a mean age of 30.5 years. Of these, 78.6% had consanguineous parents, and the first stone episode occurred at a mean of 14.82 years age. Family history of Cystinuria was encountered in 82.1%. Cystinuria was diagnosed after a mean of 6.43 years from the first stone episode, and stone analysis was performed in 22/28 after a mean of 3.86 years from the first stone episode. Only 17 patients (60.8%) underwent metabolic evaluation for kidney stones. Regarding non-surgical treatments, 13 (46.5%) patients received alkalinization medication, and only 10 (35.7%) were prescribed chelating agent therapy. Additionally, 50% of patients took herbal remedies. The diagnosis of cystinuria is often delayed, leading to a delay in receiving medical treatment (alkalinization and chelating agents) and poor health education and counseling. Thus, referring cystinuria patients to tertiary hospitals and providing a multidisciplinary approach might decrease the morbidity of the disease and enhance their well-being.

Increased kidney stone risk following total pancreatectomy with islet autotransplantation

Background/objectivesChronic pancreatitis (CP) is associated with increased risk of calcium-oxalate kidney stones, likely due to enteric hyperoxaluria. However, the risk of kidney stones for patients with CP after total pancreatectomy with islet autotransplantation (TPIAT) is unknown. We aimed to evaluate kidney stone risk in patients with CP after TPIAT. MethodsA retrospective analysis of 629 patients who underwent TPIAT was conducted to identify patients who developed kidney stones post-TPIAT. Kaplan-Meier analysis estimated time to first event. An Anderson-Gill proportional-hazards analysis of all kidney stone events described key clinical associations. ResultsMean age at TPIAT was 33 years (SD 15.3, range 3–69); 69.8 % (n = 439) were female. The estimated chance of any kidney stone episodes by 5 years post-TPIAT was 12.8 % (95 % CI: 8.8–16.6 %); by 10 years, 23.2 % (CI: 17.5–28.6 %); by 15 years, 29.4 % (CI: 21.8–36.2 %). Significant associations with kidney stones post-TPIAT included older age (HR 1.25 per 10 years), smoking history (HR 1.72), mild chronic kidney disease (HR 1.96), renal cysts (HR 3.67), pre-TPIAT kidney stones (HR 4.06), family history of kidney stones (HR 4.10), and Roux-en-Y reconstruction (HR 2.68). Of the 77 patients who developed kidney stones, 34 (44.1 %) had recurrent episodes. Of 143 total kidney stone events, 35 (24.5 %) required stone removal, 79 (55.2 %) resolved spontaneously, and 29 (20.3 %) were missing this data. ConclusionsPatients with CP post-TPIAT commonly have kidney stones: nearly 3 in 10 have ≥1 kidney stone episodes within 15 years. Clinicians should be aware of this risk and counsel patients on prevention.

International Alliance of Urolithiasis (IAU) guidelines on the management of pediatric urolithiasis.

The aim of this study was to construct the sixth in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis (IAU) that by providing a clinical framework for the management of pediatric patients with urolithiasis based on the best available published literature. All recommendations were summarized following a systematic review and assessment of literature in the PubMed database from January 1952 to December 2023. Each generated recommendation was graded using a modified GRADE methodology. Recommendations are agreed upon by Panel Members following review and discussion of the evidence. Guideline recommendations were developed that addressed the following topics: etiology, risk factors, clinical presentation and symptoms, diagnosis, conservative management, surgical interventions, prevention, and follow-up. Similarities in the treatment of primary stone episodes between children and adults, incorporating conservative management and advancements in technology for less invasive stone removal, are evident. Additionally, preventive strategies aiming to reduce recurrence rates, such as ensuring sufficient fluid intake, establishing well-planned dietary adjustments, and selective use pharmacologic therapies will also result in highly successful outcomes in pediatric stone patients. Depending on the severity of metabolic disorders and also anatomical abnormalities, a careful and close follow-up program should inevitably be planned in each pediatric patient to limit the risk of future recurrence rates.

#1621 Quantifying ureter smooth muscle electrophysiology from calcium transient images to understand abnormal peristaltic contraction

Abstract Background and Aims Abnormal peristaltic contraction of the ureter smooth muscle (USM) causes acute kidney stone episodes. Intracellular electrical activities like membrane depolarization and action potentials play important roles in modulating the USM contraction by releasing intracellular calcium from the sarcoplasmic reticulum. Therefore, an electrophysiological study will help to assess the USM cell's electrical activities and in diagnosing abnormal USM contraction. The objective of this study is to quantify the contribution of ionic currents in shaping experimental calcium transient profiles using in-silico electrophysiological modeling. Method The simultaneous experimental recording of action potential (AP) and intracellular calcium transient images from the mouse ureter is obtained. The single isolated USM cell model comprises several voltage-gated ion channels, such as two voltage-gated calcium (T—type, and L—type) channels, one voltage-gated fast potassium (KA) channel, one calcium-dependent large conductance potassium channel, and an HCN channel. To describe the calcium-dependent gating of Ca2+-dependent potassium channels and to update the equilibrium potential of the Ca2+ ion, the intracellular Ca2+ concentration is updated during the simulation period. Results Simulation of simultaneous recordings of AP and cytosolic calcium [Ca2+]i are done on a single isolated cell. The model shows [Ca2+]i as a function of synaptic input-induced AP to simulate extracted experimental data, where Ca2+ transient is recorded simultaneously during AP in mouse USM cells. Fig. 1 shows both experimental and simulation of AP (A) and Calcium transient (B) in the USM cell. In our model, the radius “r” and time constant τ of the shell influence the Ca2+ transient profile. In the USM cell model, the submembrane calcium transient occurs from a depth of 0.1 μm to a depth of 0.6 μm. We have investigated whether Ca2+ current via the L-type Ca2+ channel is responsible for the firing of APs with fast upstroke generation. The AP and calcium transients are demolished with the absence of the L-type Ca2+ channel. Conclusion From this study, it is found that inhibition of the L-type Ca2+ channel not only prevented AP generation, it also reduced the cytosolic Ca2+ transient. This study supports the application of L-type Ca2+ channel inhibitor as a potential drug for abnormal peristaltic contraction of the ureter smooth muscle.

#1472 Prevalence of Mendelian and non-Mendelian forms of genetic disease in a Swiss cohort of adult kidney stone formers

Abstract Background and Aims Molecular mechanisms of kidney stone formation remain unknown in most patients. Previous studies showed high heritability of nephrolithiasis, but analysis of Mendelian disease in selected cohorts and genome-wide analysis were yet unable to entirely explain heritability. While prevalence of Mendelian disease in selected nephrolithiasis cohorts has already been studied, data on prevalence and characteristics of genetic disease in unselected adults with nephrolithiasis are lacking. This study was conducted to fill this important knowledge gap. Method We performed whole exome sequencing in 787 participants of the Bern Kidney Stone Registry, an unselected cohort of adults with ≥1 past kidney stone episode (KSF), and 114 non-stone-forming individuals (NKSF). An exome-based panel of 34 established nephrolithiasis genes was analyzed and variants assessed according to ACMG criteria. Pathogenic (P) or likely pathogenic (LP) variants were considered diagnostic. Results Mean age of KSF was 47 ± 15 years, and 18% were first time KSF. A Mendelian kidney stone disease was present in 2.9% (23 of 787) of KSF. The most common genetic diagnoses were cystinuria (SLC3A1, SLC7A9; n = 13), Vitamin D-24 hydroxylase deficiency (CYP24A1; n = 5) and primary hyperoxaluria (AGXT, GRHPR, HOGA1; n = 3). 8.1% (64 of 787) of KSF were monoallelic for LP/P variants predisposing to nephrolithiasis, most frequently in SLC34A1/A3 or SLC9A3R1 (n = 37), CLDN16 (n = 8) and CYP24A1 (n = 8). KSF with Mendelian disease had a lower age at the first stone event (30 ± 14 years vs. 36 ± 14 years, p = 0.003), were more likely to have cystine stones (23.4% vs. 1.4%) and less likely to have calcium oxalate monohydrates stones (31.9% vs. 52.5%) compared to KSF without genetic diagnosis. The phenotype of KSF with variants predisposing to nephrolithiasis was subtle and showed significant overlap with KSF without diagnostic variants. In NKSF, no Mendelian disease was detected, and LP/P variants were significantly less prevalent compared to KSF (1.8% vs. 8.1%). Conclusion Mendelian disease is uncommon in unselected adult KSF, yet variants predisposing to nephrolithiasis are significantly enriched in adult KSF. While the identified variants predisposing to nephrolithiasis may explain some of the unresolved heritability, likely additional intermediate effect size variants in known and yet unknown kidney stone genes remain to be discovered for us to fully understand the genetic factors leading to the high heritability of nephrolithiasis.

Prevalence and characteristics of genetic disease in adult kidney stone formers.

Molecular mechanisms of kidney stone formation remain unknown in most patients. Previous studies have shown a high heritability of nephrolithiasis, but data on the prevalence and characteristics of genetic disease in unselected adults with nephrolithiasis are lacking. This study was conducted to fill this important knowledge gap. We performed whole exome sequencing in 787 participants in the Bern Kidney Stone Registry, an unselected cohort of adults with one or more past kidney stone episodes [kidney stone formers (KSFs)] and 114 non-kidney stone formers (NKSFs). An exome-based panel of 34 established nephrolithiasis genes was analysed and variants assessed according to American College of Medical Genetics and Genomics criteria. Pathogenic (P) or likely pathogenic (LP) variants were considered diagnostic. The mean age of KSFs was 47±15years and 18% were first-time KSFs. A Mendelian kidney stone disease was present in 2.9% (23/787) of KSFs. The most common genetic diagnoses were cystinuria (SLC3A1, SLC7A9; n=13), vitamin D-24 hydroxylase deficiency (CYP24A1; n=5) and primary hyperoxaluria (AGXT, GRHPR, HOGA1; n=3). Of the KSFs, 8.1% (64/787) were monoallelic for LP/P variants predisposing to nephrolithiasis, most frequently in SLC34A1/A3 or SLC9A3R1 (n=37), CLDN16 (n=8) and CYP24A1 (n=8). KSFs with Mendelian disease had a lower age at the first stone event (30±14 versus 36±14years; P=.003), were more likely to have cystine stones (23.4% versus 1.4%) and less likely to have calcium oxalate monohydrates stones (31.9% versus 52.5%) compared with KSFs without a genetic diagnosis. The phenotype of KSFs with variants predisposing to nephrolithiasis was subtle and showed significant overlap with KSFs without diagnostic variants. In NKSFs, no Mendelian disease was detected and LP/P variants were significantly less prevalent compared with KSFs (1.8% versus 8.1%). Mendelian disease is uncommon in unselected adult KSFs, yet variants predisposing to nephrolithiasis are significantly enriched in adult KSFs.

Incidence and trends in the treatment of kidney stones in Canada A population-based cohort study.

Our objective was to assess the incidence of kidney stones requiring acute care, trends in the surgical treatment of stones, and the demographics of stone formers in Canada. We conducted a population-based, retrospective cohort study using administrative data from the Canadian Institute for Health Information. We included Canadian residents age >18 years, outside of Quebec, who presented between January 1, 2013, and December 31, 2018, with a kidney stone episode. This was defined as a kidney stone resulting in hospital admission, emergency department visit, or stone intervention, specifically shockwave lithotripsy (SWL), ureteroscopy (URS), or percutaneous nephrolithotomy (PCNL). There were 471 824 kidney stone episodes, including 184 373 interventions. The number of kidney stone episode increased from 277/100 000 in 2013 to 290/100 000 in 2018. The median age was 53 (interquartile range 41-65) years and 59.9% were male. The crude rate for stone intervention was 877/100 000. The age- and gender-standardized rate for interventions was highest in Nova Scotia and Newfoundland and Labrador, and lowest in Prince Edward Island. The most common intervention in Canada was URS (73.5%), followed by SWL (19.8%) and PCNL (6.7%). The percent utilization of SWL was highest in Manitoba, whereas for URS, it was highest in Prince Edward Island and Alberta. Our study provides the first population-based data on the demographics of stone formers and treatment trends across Canada. There has been a 4.7% increase in kidney stone episodes over the study period. Those presenting to hospital or requiring intervention for a kidney stone are more likely to be male, aged 41-65, and undergo URS.

The significance of clinically insignificant residual fragments after percutaneous nephrolithotomy: an analysis into the relevance of complete stone clearance

PurposeAfter treatment for kidney stones, residual fragments with a diameter of ≤ 4 mm are traditionally referred to as ‘clinically insignificant residual fragments’. We hypothesize that patients with these fragments are at an increased risk for stone-related morbidity, such as complaints, hydronephrosis, and stone regrowth, when compared to stone-free patients. This study aimed to investigate the relevance of complete stone clearance in surgical treatment of urolithiasis.MethodsWe conducted a single-center retrospective cohort study. Patients who underwent percutaneous nephrolithotomy between 2015 and 2020 were included if a CT-scan was available within 6 months after the procedure, and the follow-up duration was at least 1 year. The stone-free status at the end of the first stone episode during the study period was categorized as fully stone-free, not stone-free with small residual fragments (≤ 4 mm) and not stone-free with large residual fragments (> 4 mm). Follow-up data were collected, including stone-related events and re-intervention rates.ResultsA total of 103 subjects were included with a median follow-up of 21.4 months. Stone-related events occurred in 10 (29.4%) of the fully stone-free subjects, 20 (58.8%) of the subjects with small residual fragments and 25 (71.4%) of the subjects with large residual fragments. The stone-related event-free survival per subgroup resulted in a significantly different survival distribution in a log rank test (p = 0.008).ConclusionA complete stone-free status seems to be of fundamental importance for decreasing stone-related morbidity. Further developments and research should focus on optimizing the full clearance of stone material during PCNL.

Preventive Pharmacological Therapy and Risk of Recurrent Urinary Stone Disease.

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. 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. 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). 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.

Comparison of Radiation Exposure for Pregnant Patients Requiring Intervention for Suspected Obstructing Nephrolithiasis

To identify the differences in radiation exposure per suspected stone episode between percutaneous nephrostomy tube (PCN), stent, and primary ureteroscopy (URS).The incidence of nephrolithiasis in pregnancy is low; however, repercussions for both mother and fetus can be significant. In cases of suspected obstructing nephrolithiasis, intervention may be required, including ureteral stent, PCN, or URS, with the potential for multiple subsequent procedures that often utilize fluoroscopy. Pregnant patients who required an intervention (stent, PCN, or URS) for suspected obstructing nephrolithiasis were retrospectively reviewed. The primary outcome was total fluoroscopy exposure per suspected stone episode. Secondary outcomes included fluoroscopic exposure per procedure and number of procedures required. After excluding patients with renal anomalies and incomplete radiation data, 78 out of 100 patients were included in the analysis. Forty patients (51.3%) underwent initial stent placement, 22 (28.2%) underwent initial PCN placement, and 16 (20.5%) underwent primary URS. Total mean radiation exposure per stone episode was significantly higher in patients who underwent PCN, (286.9mGy vs 3.7mGy (stent) and 0.2mGy (URS), P<.001). In addition, patients who underwent initial PCN placement had significantly more procedures (P<.001) and mean radiation exposure per procedure was higher (P<.001). More than 40% of PCNs experienced dysfunction, and mean duration between PCN exchanges was 16.5days. In pregnant patients with suspected obstructing nephrolithiasis requiring intervention, initial PCN placement was associated with a significantly higher number of procedures, radiation exposure per procedure, and total radiation exposure per suspected stone episode compared to stent and URS.

Patient compliance for metabolic evaluation and medical treatment (CoMET) in calcium-oxalate stone patients: prospective study by EULIS eCORE study group.

In this study, we aimed to identify the compliance rates of calcium-oxalate stone patients for metabolic evaluation, diet and medical treatment and also determine the factors that are associated with poor compliance rates. This study was conducted by the EULIS eCORE working group prospectively. In the initial visit, demographic and stone-related characteristics were recorded. Patients were suggested metabolic evaluation, dietary advices and medical treatment. Follow-up visit was performed after 3months and compliance rates were recorded. Logistic regression analysis was performed to determine factors associated with poor compliance to metabolic evaluation, diet and medical treatment. Data of 346 patients from nine centers were analyzed. Compliance rates were 71.7%, 65.3%, and 63.7% for metabolic evaluation, diet, and medical treatment, respectively. In multivariate analysis, level of education (p = 0.003), history of emergency department visit (p = 0.04), number of stone surgeries (p = 0.03), patient care in dedicated stone clinic (p = 0.03), and history of shock wave lithotripsy (p = 0.005) were detected as independent predictors of compliance to metabolic analysis. Level of education (p < 0.001) and history of emergency department visit (p = 0.01) were detected as independent predictors of patient compliance to diet. Number of stone episodes (p = 0.03), family history of stones (p = 0.02), and polypharmacy (p < 0.001) were detected as independent predictors of patient compliance to medical treatment. Patient compliance to metabolic evaluation, diet, and medical therapy is important for successful management of urolithiasis. Dietary advices and medications should be personalized by taking in to account the factors associated with poor compliance.

The intestinal microbiome of children with initial and recurrent nephrolithiasis: A pilot study and exploratory analysis

Kidney stone disease in children is rising disproportionate to the general population, representing a disease population with a distinct biological mechanism as compared to adults. Factors influencing recurrent kidney stone disease in children are poorly characterized and the associations of the intestinal microbiome within sub-populations of kidney stone formers, however, are not well described. We evaluated a pilot cohort of children with nephrolithiasis comparing patients based on recurrent kidney stone episodes and abnormal 24-h urinary parameters, with dual aims to compare the microbiome signal in children with initial and recurrent nephrolithiasis and to explore additional associations in microbiome composition and diversity within this population. Children aged 6-18 with a history of nephrolithiasis, without an active ureteral calculus or antibiotic exposure within 30 days of study entry were eligible to participate. All participants had a 24-h urine study within 6 months of study entry and provided a fecal sample. Microbiome samples were analyzed using 16S ribosomal DNA sequencing techniques for alpha and beta diversity comparing initial and recurrent stone formers as well as microbiome multivariate association (MaAsLin2) to determine differentially abundant taxa. Shotgun sequencing reads were aligned to custom oxidase degradation and butyrate production gene databases (5 databases total). Comparisons for MaAsLin2 and shotgun metagenomics, normalized to sequencing depth, were based on stone recurrence, sex, hypercalcuria (≤4mg/kg/day), hyperoxaluria (≥45 mg/1.73m2), and hypocitraturia (<310 mg/1.73 m2 [females] or<365 mg/1.73 m2 [males]). A total of 16 enrolled children provided samples sufficient for analyses, including 9 girls and 7 boys, of whom 5 had experienced recurrent kidney stone events. Three participants had hypercalcuria, 2 had hyperoxaluria, and 4 had hypocitraturia. Comparisons of Formyl-CoA transferase between index and recurrent urinary stone disease revealed a trend towards higher mean abundance of the gene in initial stone formers (0.166% vs 0.0343%, p=0.2847) (Summary Figure), while trends toward lower biodiversity were also noted in the recurrent stone cohort on both Faith (p=0.06) and Shannon (p=0.05) indices. Exploratory analyses found Eubacterium siraeum to be significantly greater in relative abundance in children with documented hypercalciuria (p=0.001). Our pilot study demonstrates possible signals in both microbial diversity and oxalate gene expression, both of which are lower in recurrent pediatric kidney stone patients. These findings warrant further investigation as a potential diagnostic marker for future kidney stone events.

The Most Common Type of Kidney Stone and High Incidence in Males or Female

In the renal calyces and pelvis, mineral deposits known as kidney stones can be found either loosely or firmly attached to the renal papillae. They comprise both crystalline and organic molecules and are produced when the urine is very saturated with a specific mineral. The majority of stones are mostly formed of calcium oxalate, and a lot of these stones form on Randall's plaques on the renal papillary floor, which are made of calcium phosphate. In the first five years after the initial stone episode, charges of up to 50% may recur. There are charges of up to 14.8% and increasing for stone creation. Risk factors for kidney stone development include obesity, diabetes, high blood pressure, and metabolic syndrome. Kidney stones can then lead to hypertension, chronic kidney disease, and end-stage renal disease. Less invasive endourological techniques have replaced open surgical lithotomy for the treatment of symptomatic kidney stones, reducing patient morbidity, increasing stone-free rates, and improving quality of life. Prevention of recurrence requires behavioral and nutritional adjustments in addition to drugs according to the kind of stone. The creation of stronger capsules and the pressing need for recurrence prevention necessitate a greater comprehension of the mechanisms behind stone formation.

Evaluation of risk factors for recurrent renal stone formation among Saudi Arabian patients: Comparison with first renal stone episode.

We evaluated the baseline characteristics, and risk factors of renal stone recurrence among Saudi Arabian patients after successful primary stone treatment. In this cross-sectional comparative study, we reviewed the medical records of patients who presented consecutively with a first renal stone episode from 2015 to 2021 and were followed-up by mail questionnaire, telephone interviews, and/or outpatient clinic visit. We included patients who achieved stone-free status after primary treatment. Patients were divided into two groups: group I (patients with first episode renal stone) and group Ⅱ (patients who developed renal stone recurrence). The study outcomes were to compare the demographics of both groups and to evaluate the risk factors of renal stone recurrence after successful primary treatment. We used Student's t-test, Mann Whitney test or chi-square (x2) to compare variables between groups. Cox regression analyses were used to examine the predictors. We investigated 1260 participants (820 males and 440 females). Of this number, 877 (69.6%) didn't develop renal stone recurrence and 383 (30.4%) had recurrence. Primary treatments were percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), extracorporeal shock wave lithotripsy (ESWL), surgery and medical treatment in 22.5%, 34.7%, 26.5%, 10.3%, and 6%, respectively. After primary treatment, 970 (77%) and 1011 (80.2%) of patients didn't have either stone chemical analysis or metabolic work-up, respectively. Multivariate logistic regression analysis revealed that male gender (OR: 1.686; 95% CI, 1.216-2.337), hypertension (OR: 2.342; 95% CI, 1.439-3.812), primary hyperparathyroidism (OR: 2.806; 95% CI, 1.510-5.215), low fluid intake (OR: 28.398; 95% CI, 18.158-44.403) and high daily protein intake (OR: 10.058; 95% CI, 6.400-15.807) were predictors of renal stone recurrence. Male gender, hypertension, primary hyperparathyroidism, low fluid intake and high daily protein intake increase the risk of renal stone recurrence among Saudi Arabian patients.