Sex-specific Stone-forming Phenotype in Mice During Hypercalciuria/Urine Alkalinization.

Sex differences in kidney stone formation are well known. Females generally have slightly acidic blood and higher urine pH when compared with males, which makes them more vulnerable to calcium stone formation, yet the mechanism is still unclear. We aimed to examine the role of sex in stone formation during hypercalciuria and urine alkalinization through acetazolamide and calcium gluconate supplementation, respectively, for 4 weeks in wild-type (WT) and moderately hypercalciuric [TRPC3 knockout [KO](-/-)] male and female mice. Our goal was to develop calcium phosphate (CaP) and CaP+ calcium oxalate mixed stones in our animal model to understand the underlying sex-based mechanism of calcium nephrolithiasis. Our results from the analyses of mice urine, serum, and kidney tissues show that female mice (WT and KO) produce more urinary CaP crystals, higher [Ca2+], and pH in urine compared to their male counterparts. We identified a sex-based relationship of stone-forming phenotypes (types of stones) in our mice model following urine alkalization/calcium supplementation, and our findings suggest that female mice are more susceptible to CaP stones under those conditions. Calcification and fibrotic and inflammatory markers were elevated in treated female mice compared with their male counterparts, and more so in TRPC3 KO mice compared with their WT counterparts. Together these findings contribute to a mechanistic understanding of sex-influenced CaP and mixed stone formation that can be used as a basis for determining the factors in sex-related clinical studies.

Climate change and kidney stones.

PURPOSE OF REVIEW: Kidney stones affect an increasing proportion of the population. We suggest that these trends are in part influenced by exposure to higher temperatures as a result of climate change and urbanization. The changing epidemiology of kidney stones is a topic worthy of discussion due to the economic and healthcare burden the condition poses as well as the quality-of-life disruption faced by individuals with kidney stones. RECENT FINDINGS: The relationship between heat and kidney stones is well supported. Exposure to high temperatures has been shown to increase risk for stone development within a short time frame. Effects are modified by factors such as sex, comorbid conditions, and population vulnerability and adaptability. Urban heat islands (UHIs) likely exaggerate the effect of increasing global surface temperature. The concentration of UHIs often coincides with historic redlining practices in the United States, potentially contributing to observed disparities in kidney health among minoritized populations. As global surface temperature increases and urbanization trends continue, a greater proportion of the world's population is exposed to significant temperature extremes each year, leading to the expectation that kidney stone prevalence will continue to increase. SUMMARY: This work describes the effect of increasing global surface temperature as a result of climate change on kidney stone disease and kidney health. These effects may result in further perpetuation of significant kidney stone related social disparities. We suggest strategies to mitigate the effects of heat exposure on stone formation.

24-Hour Urinary Chemistries and Kidney Stone Risk.

RATIONALE & OBJECTIVE: Most previous studies of the relationship between urinary factors and kidney stone risk have either assumed a linear effect of urinary parameters on kidney stone risk or implemented arbitrary thresholds suggesting biologically implausible "all-or-nothing" effects. In addition, little is known about the hierarchy of effects of urinary factors on kidney stone risk. This study evaluated the independent associations between urine chemistries and kidney stone formation and examined their magnitude and shape. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: We analyzed 9,045 24-hour urine collections from 6,217 participants of the Health Professionals Follow-Up Study and Nurses' Health Studies I and II. EXPOSURE: Urine volume and pH, and concentrations of calcium, citrate, oxalate, potassium, magnesium, uric acid, phosphorus, and sodium. OUTCOME: Incident symptomatic kidney stones. ANALYTICAL APPROACH: Multivariable logistic regression analysis incorporating restricted cubic splines to explore potentially nonlinear relationships between urinary factors and the risk of forming a kidney stone. Optimal inflection point analysis was implemented for each factor, and dominance analysis was performed to establish the relative importance of each urinary factor. RESULTS: Each urinary factor was significantly associated with stone formation except for urine pH. Higher urinary levels of calcium, oxalate, phosphorus, and sodium were associated with a higher risk of stone formation whereas higher urine volume, uric acid, citrate, potassium, and magnesium were associated with a lower risk. The relationships were substantially linear for urine calcium, uric acid, and sodium. By contrast, the magnitudes of the relationships were modestly attenuated at levels above the inflection points for urine oxalate, citrate, volume, phosphorus, potassium, and magnesium. Dominance analysis identified 3 categories of factors' relative importance: higher (calcium, volume, and citrate), intermediate (oxalate, potassium, and magnesium), and lower (uric acid, phosphorus, and sodium). LIMITATIONS: Predominantly White participants, lack of information on stone composition. CONCLUSIONS: Urine chemistries have complex relationships and differential relative associations with the risk of kidney stone formation. PLAIN-LANGUAGE SUMMARY: Kidney stones are common and likely to recur. Certain urinary factors play a role in the development of stones, but their independent roles, relative importance, and shapes of association with stone formation are not well-characterized. We analyzed 24-hour urine collections from individuals with and without kidney stones. Stones were less likely in those with higher urine volume, citrate, potassium, magnesium, and uric acid and were more likely in those with higher calcium, oxalate, phosphorus, and sodium. The acidity of the urine was not related to stones. The urinary parameters showed different degrees of relative importance, with calcium, volume, and citrate being greatest. All parameters exhibited a linear or close-to-linear shape of association with stone formation.

Play it safe: renal function after bilateral flexible ureteroscopy for kidney stones.

PURPOSE: We searched for perioperative renal function deterioration risk factors in patients that underwent bilateral flexible ureteroscopy (fURS) for kidney stones. METHODS: From August 2016 to February 2020, symptomatic patients > 18 years old with bilateral kidney stones up to 20 mm in each side were prospectively studied. Serum creatinine samples were collected on admission to surgery, immediate postoperative (IPO), on POD 3, 10, and 30. Estimated glomerular filtration rate (eGFR) was calculated using Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) without a race coefficient. RESULTS: Thirty patients underwent bilateral fURS. Comparing to preoperative eGFR, median IPO and POD3 eGFR (p < 0.001) were significantly lower, and POD10 (p = 0.092) and POD30 (p = 0.648) were similar to preoperative eGFR. During follow-up, 22/30 (73.3%), 14/30 (46.7%), and 7/30 (23.3%) of the patients presented a decrease > 10% eGFR, > 20% eGFR, and > 30% eGFR, respectively. Multivariate analysis demonstrated that lower preoperative eGFR is a risk factor for eGFR < 60 mL/min/1.73 m2, p = 0.019 [1.021-1.263; 1.136]; ASA > 1 is a risk factor for decrease of eGFR > 10%, p = 0.028 [1.25-51.13; 8.00]; longer operative time is a risk factor for decrease of eGFR > 20%, p = 0.042 [1.00-1.05; 1.028]; and operative time ≥ 120 min is a risk factor for decrease of eGFR > 30%, p = 0.026 [0.016-0.773; 0.113]. CONCLUSIONS: Renal function suffers a reversible decrease after bilateral fURS. Our study suggests that adequate selection of patients and maintaining operative time < 120 min are relevant factors in preventing acute renal function deterioration following bilateral fURS.

Ureteral stent after PCNL: is leaving the threads through the percutaneous tract safe and better tolerated?

OBJECTIVE: To assess safety, urinary symptoms, and feasibility of JJ stent removal with exteriorized threads through the percutaneous tract after percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: Prospective, transversal, comparative, experimental, randomized 1-to-1 cohort study in 52 patients who underwent "tubeless" PCNL from October 2020 to November 2022. Group A with threads through the urethra and Group B through the percutaneous tract. The validated USSQ (Ureteral Stent Symptom Questionnaire) was applied in the Urology office a week after the procedure, and the JJ stent was withdrawn by pulling the threads. Hemoglobin and urine culture, and pre- and post-surgery were evaluated. RESULTS: There is a statistically significant difference in favor of group B when comparing urinary symptoms (p = 0.008), body pain (p = 0.009), and general condition (p = 0.042), mainly for non-urgency incontinence, frequency of analgesic use, and dysuria. There were significant differences between groups (p = 0.028, p = 0.026, p = 0.027, respectively). There is no association with urinary infections (p = 0.603) nor an increased risk of bleeding (p = 0.321). CONCLUSION: The removal of the JJ stent with exteriorized threads through the percutaneous tract after PCNL in the office is a feasible and safe procedure if it is removed before 8 days and has better tolerance regarding the urinary symptoms.

Ureteral wall thickness as a predictor for non-invasive treatment success for steinstrasse. Can we save time?

PURPOSE: We aimed to define factors affecting the non-invasive overall treatment success (medical expulsive therapy (MET) ± shock wave lithotripsy (SWL)) for uncomplicated ureteral steinstrasse (SS) clearance. METHODS: We retrospectively evaluated consecutive patients who underwent SWL for renal stones between 2017 and 2021. Patients with uncomplicated SS were included. All patient's demographic and radiological data, e.g., age, gender, pre-SWL stenting, SS site, type, leading stone size in widest diameter (< 10 mm and ≥ 10 mm), ureteral wall thickness (UWT) in mm against the leading stone were collected. If SS was diagnosed, medical treatment was given for 4 weeks. In case of MET failure, either SWL for the leading stones + MET or direct URS was done. Non-invasive treatment success (SFR) was considered if complete clearance of SS occurred with no complications or the need for invasive intervention. RESULTS: A total of 145 patients were included with mean age of 45.9 ± 12.4 years. SFR in case of MET only occurred in 27.9%. Complications happened in 26 patients (17.9%). Non-invasive treatment SFR was achieved in 78 patients (53.8%) totally where SS type I, leading stone size ≤ 10 mm type and decreased UWT around the leading stone increased treatment success. CONCLUSION: Ureteral wall thickness is an important factor predicting SS management success. Besides the decreased UWT, non-invasive management should be offered for type I SS with leading stone ≤ 10 mm.

Climate change and its implications for kidney health.

PURPOSE OF REVIEW: Extremes of weather as a result of climate change are affecting social, economic and health systems. Kidney health is being threatened by global warming while treatment of kidney disease is contributing to increasing resource utilization and leaving a substantial carbon footprint. Improved physician awareness and patient education are needed to mitigate the risk. RECENT FINDINGS: Rising temperatures are changing kidney disease patterns, with increasing prevalence of acute kidney injury, chronic kidney disease and kidney stones. These issues disproportionately affect people suffering from social inequality and limited access to resources. SUMMARY: In this article, we review the effects of climate change on kidney stones, and acute and chronic kidney injury. Finally, we discuss the impact of renal replacement therapies on the environment and proposed ways to mitigate it.

Natural history of urine and plasma oxalate in children with primary hyperoxaluria type 1.

BACKGROUND: Primary hyperoxaluria type 1 (PH1) is a rare, severe genetic disease causing increased hepatic oxalate production resulting in urinary stone disease, nephrocalcinosis, and often progressive chronic kidney disease. Little is known about the natural history of urine and plasma oxalate values over time in children with PH1. METHODS: For this retrospective observational study, we analyzed data from genetically confirmed PH1 patients enrolled in the Rare Kidney Stone Consortium PH Registry between 2003 and 2018 who had at least 2 measurements before age 18 years of urine oxalate-to-creatinine ratio (Uox:cr), 24-h urine oxalate excretion normalized to body surface area (24-h Uox), or plasma oxalate concentration (Pox). We compared values among 3 groups: homozygous G170R, heterozygous G170R, and non-G170R AGXT variants both before and after initiating pyridoxine (B6). RESULTS: Of 403 patients with PH1 in the registry, 83 met the inclusion criteria. Uox:cr decreased rapidly over the first 5 years of life. Both before and after B6 initiation, patients with non-G170R had the highest Uox:cr, 24-h Uox, and Pox. Patients with heterozygous G170R had similar Uox:cr to homozygous G170R prior to B6. Patients with homozygous G170R had the lowest 24-h Uox and Uox:cr after B6. Urinary oxalate excretion and Pox tend to decrease over time during childhood. eGFR over time was not different among groups. CONCLUSIONS: Children with PH1 under 5 years old have relatively higher urinary oxalate excretion which may put them at greater risk for nephrocalcinosis and kidney failure than older PH1 patients. Those with homozygous G170R variants may have milder disease. A higher resolution version of the Graphical abstract is available as Supplementary information.

Comparison of percutaneous nephrolithotomy and flexible ureterorenoscopy in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters: a retrospective study.

PURPOSE: To compare the efficacy and safety of micropercutaneous nephrolithotomy (MPCNL) and flexible ureteroscopy (FURS) in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters. METHODS: This study is a retrospective analysis that combines a review of medical records with an outcomes management database. A total of 163 patients who underwent MPCNL and 137 patients who had FURS were identified between January 2017 and December 2021. Demographic data, operation time, hospitalization time, stone-free rate, and complication rate were collected and analyzed. RESULTS: Preoperative general data of sex, age, BMI, serum creatinine, time of stone existence, stone hardness, stone diameter, preoperative hydronephrosis, and preoperative infection of the MPCNL group have no statistically significant difference with that of the FURS group. All MPCNL or FURS operations in both groups were successfully completed without any instances of reoperation or conversion to another surgical procedure. Patients who underwent MPCNL had a considerably reduced operation time (49.6 vs. 72.4 min; P<0.001), but a higher duration of hospitalization (9.1 vs. 3.9 days; P<0.001) compared to those who underwent FURS. The stone-free rate in the MPCNL group was superior to that of the FURS group, with a percentage of 90.8% compared to 71.5% (P<0.001). There was no statistically significant disparity in the rate of complications between the two groups (13.5% vs. 15.3%; P = 0.741). CONCLUSION: Both MPCNL and FURS are viable and secure surgical choices for individuals with solitary upper ureteral calculi measuring 1 to 2 cm. The FURS procedure resulted in a shorter duration of hospitalization compared to MPCNL. However, it had a comparatively lower rate of successfully removing the stones and required a longer duration for the operation.There were no substantial disparities observed in the complication rate between the two groups.FURS is the preferable option for treating uncomplicated upper ureteral calculi, whereas MPCNL is the preferable option for treating complicated upper ureteral calculi.Prior to making treatment options, it is crucial to take into account the expertise of surgeons, the quality of the equipment, and the preferences of the patient. TRIAL REGISTRATION: No.

Association between oxidative balance score and kidney stones: data from the national health and nutrition examination survey (NHANES).

PURPOSE: Some studies have found that the pathological formation of kidney stones is closely related to injury and inflammatory response. Behaviors such as dietary composition, physical activity, obesity and smoking can all affect the body's oxidative stress levels. In order to evaluate the effects of various diets and lifestyles on the body's oxidative and antioxidant systems, an oxidative balance score was developed. To investigate whether the OBS is associated with the development of kidney stones. METHODS: Data were taken from the National Health and Nutrition Examination Survey (NHANES) from 2007-2018, followed by retrospective observational studies. The association between kidney stones and OBS was analyzed using survey-weighted logistic regression by adjusting for demographics, laboratory tests, and medical comorbidity covariates. The oxidative balance score is calculated by screening 16 nutrients and 4 lifestyle factors, including 5 prooxidants and 15 antioxidants, based on prior information about the relationship between oxidation levels in the body and nutrients or lifestyle factors. RESULTS: A total of 26,786 adult participants were included in the study, of which 2,578, or 9.62%, had a history of nephrolithiasis. Weighted logistic regression analysis found an association between OBS and kidney stones. In the fully tuned model, i.e., model 3, the highest quartile array of OBS was associated with the lowest quartile array of OBS (OR = 0.73 (0.57, 0.92)) with the risk of kidney stone (p = 0.01), and was statistically significant and remained relatively stable in each model. At the same time, the trend test in the model is also statistically significant. With the increase of OBS, the OR value of kidney stones generally tends to decrease. CONCLUSIONS: There is an inverse correlation between OBS and kidney stone disease. At the same time, higher OBS suggests that antioxidant exposure is greater than pro-oxidative exposure in diet and lifestyle, and is associated with a lower risk of kidney stones.

Association between drinking status and risk of kidney stones among United States adults: NHANES 2007-2018.

OBJECTIVE: This study aimed to investigate the relationship between drinking status and kidney stones occurrence among United States (US) adults who consume alcohol. METHODS: We conducted a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES 2007-2018). Questionnaires yielded information on alcohol consumption and kidney health. Drinking status was categorized into four groups-former, mild, moderate, and heavy-based on alcohol consumption patterns. The aim was to explore the relationship between drinking status and the prevalence of kidney stones occurrence. For this analysis, we examined a group of individuals diagnosed with kidney stones. With survey weights applied, the total weight of the group was 185,690,415. RESULTS: We used logistic regression to measure the relationship between drinking status and the likelihood of developing kidney stones. In a fully adjusted model, former drinkers were less likely to have previously experienced kidney stones (OR 0.762, 95% CI 0.595-0.977, P < 0.05). In subgroup analysis, heavy alcohol consumption was associated with a significantly reduced likelihood of kidney stones occurrence in various populations. The adjusted odds ratios (with 95% confidence intervals) of kidney stones risk for heavy alcohol consumption were 0.745 (0.566-0.981) for young individuals, 0.566 (0.342-0.939) for older individuals, 0.708 (0.510-0.981) for individuals of white race, 0.468 (0.269-0.817) for individuals with underweight/normal BMI, 0.192 (0.066-0.560) for widowed people, 0.538 (0.343-0.843) for smoking individuals, 0.749 (0.595-0.941) for individuals without a cancer history, and 0.724 (0.566-0.925) for individuals without a stroke history. CONCLUSIONS: In US adults who consume alcohol, a negative linear relationship is apparent between drinking status and the prevalence of kidney stones, with heavy drinking showing a lower prevalence compared to former drinkers. However, the causal relationship between drinking status and kidney stones requires further investigation in future research endeavors.

Kidney stones and dietary intake in adults: a population-based study in southwest Iran.

BACKGROUND: The prevalence of kidney stones is on the rise globally. Several risk factors, including lifestyle, contribute to the formation of kidney stones. Nevertheless, there is a contentious debate about the relationship between diet and kidney stones. Therefore, our study aimed to assess the relationship between macronutrients and micronutrients and the formation of kidney stones. METHODS: This population-based cross-sectional study was conducted in the baseline phase of the Hoveyzeh Cohort Study, focusing on adults aged 35-70 in southwest Iran. The information on demographic characteristics, anthropometrics, kidney stone history, and food frequency was collected. Chi-square and t-tests were utilized to assess the relationship between categorical and numerical variables with kidney stones. The ANCOVA and logistic regression models were used to evaluate the relationships while controlling for confounding factors. RESULTS: Among 10,009 participants, the overall prevalence of kidney stones was 18.77% (95% CI: 17.99-19.53). A higher intake of carbohydrates [OR = 1.02 (95% CI:1.002-1.03), p = 0.026] and copper [OR = 1.04 (95% CI:1.01-1.09), p = 0.025] were found to be associated with kidney stones. No associations were found between the other assessed macronutrients or micronutrients and kidney stones (p-tvalues > 0.05). CONCLUSION: Our study's findings indicate a correlation between diet and the formation of kidney stones. However, the relationship between dietary factors and kidney stones is complex, and further research is needed.

Pathophysiology and Main Molecular Mechanisms of Urinary Stone Formation and Recurrence.

Kidney stone disease (KSD) is one of the most common urological diseases. The incidence of kidney stones has increased dramatically in the last few decades. Kidney stones are mineral deposits in the calyces or the pelvis, free or attached to the renal papillae. They contain crystals and organic components, and they are made when urine is supersaturated with minerals. Calcium-containing stones are the most common, with calcium oxalate as the main component of most stones. However, many of these form on a calcium phosphate matrix called Randall's plaque, which is found on the surface of the kidney papilla. The etiology is multifactorial, and the recurrence rate is as high as 50% within 5 years after the first stone onset. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more effective drugs. This review aims to understand the pathophysiology and the main molecular mechanisms known to date to prevent recurrences, which requires behavioral and nutritional interventions, as well as pharmacological treatments that are specific to the type of stone.

The Rise in Tubular pH during Hypercalciuria Exacerbates Calcium Stone Formation.

In calcium nephrolithiasis (CaNL), most calcium kidney stones are identified as calcium oxalate (CaOx) with variable amounts of calcium phosphate (CaP), where CaP is found as the core component. The nucleation of CaP could be the first step of CaP+CaOx (mixed) stone formation. High urinary supersaturation of CaP due to hypercalciuria and an elevated urine pH have been described as the two main factors in the nucleation of CaP crystals. Our previous in vivo findings (in mice) show that transient receptor potential canonical type 3 (TRPC3)-mediated Ca2+ entry triggers a transepithelial Ca2+ flux to regulate proximal tubular (PT) luminal [Ca2+], and TRPC3-knockout (KO; -/-) mice exhibited moderate hypercalciuria and microcrystal formation at the loop of Henle (LOH). Therefore, we utilized TRPC3 KO mice and exposed them to both hypercalciuric [2% calcium gluconate (CaG) treatment] and alkalineuric conditions [0.08% acetazolamide (ACZ) treatment] to generate a CaNL phenotype. Our results revealed a significant CaP and mixed crystal formation in those treated KO mice (KOT) compared to their WT counterparts (WTT). Importantly, prolonged exposure to CaG and ACZ resulted in a further increase in crystal size for both treated groups (WTT and KOT), but the KOT mice crystal sizes were markedly larger. Moreover, kidney tissue sections of the KOT mice displayed a greater CaP and mixed microcrystal formation than the kidney sections of the WTT group, specifically in the outer and inner medullary and calyceal region; thus, a higher degree of calcifications and mixed calcium lithiasis in the kidneys of the KOT group was displayed. In our effort to find the Ca2+ signaling pathophysiology of PT cells, we found that PT cells from both treated groups (WTT and KOT) elicited a larger Ca2+ entry compared to the WT counterparts because of significant inhibition by the store-operated Ca2+ entry (SOCE) inhibitor, Pyr6. In the presence of both SOCE (Pyr6) and ROCE (receptor-operated Ca2+ entry) inhibitors (Pyr10), Ca2+ entry by WTT cells was moderately inhibited, suggesting that the Ca2+ and pH levels exerted sensitivity changes in response to ROCE and SOCE. An assessment of the gene expression profiles in the PT cells of WTT and KOT mice revealed a safeguarding effect of TRPC3 against detrimental processes (calcification, fibrosis, inflammation, and apoptosis) in the presence of higher pH and hypercalciuric conditions in mice. Together, these findings show that compromise in both the ROCE and SOCE mechanisms in the absence of TRPC3 under hypercalciuric plus higher tubular pH conditions results in higher CaP and mixed crystal formation and that TRPC3 is protective against those adverse effects.

[Living-donor kidney graft ex vivo endoscopic nephrolithotomy with flexible instrument]. / Nefrolitotomía Endoscópica ex vivo del injerto renal de donante vivo con instrumento flexible.

INTRODUCTION: The finding of an asymptomatic stone in the study of a living kidney donor does not necessarily contraindicate donation, however, there is no consensus on the management of these cases. The use of a graft with lithiasis may represent a risk of recurrence in the remaining kidney in the donor and eventual obstructive complications in the transplanted kidney. The objective of this work is to present the usefulness of ureteroscopy (URS) to resolve lithiasis ex vivo before transplantation. MATERIAL AND METHODS: Donors with a small, asymptomatic kidney stone and with an analysis of lithogenic factors without relevant findings were considered to continue in the donation process. The kidney unit with stone was selected for nephrectomy. RESULTS: Four donor kidneys underwent flexible URS after nephrectomy under hypothermic preservation conditions during bench preparation. The average time of the procedure was 35 minutes and the stone was extracted in all cases without incident. The transplant was carried out in the usual way and the evolution of the recipients was without complications and with excellent renal function. During follow-up, no recurrence of lithiasis was observed in donors or recipients. CONCLUSIONS: In this experience, the URS of the donor kidney was a feasible procedure and was not associated with adverse consequences for the graft. The main advantage of this procedure is to avoid the potential risk to the recipient of an obstructive graft complication.

[The efficiency of totally tubeless percutaneous nephrolithotomy: analysis of 40 cases].

INTRODUCTION: Previously, the placement of a nephrostomy tube was considered standard practice during percutaneous nephrolithotomy (PCNL) to ensure repeat access and kidney assessment. However, some publications have shown that in certain cases, a totally tubeless approach may be a viable alternative, provided that PCNL is performed properly and safely. AIM: To analyze the results and complications of totally tubeless PCNL. MATERIALS AND METHODS: A retrospective analysis of 40 patients with renal stones who underwent totally tubeless PCNL using a single percutaneous access of 16 Ch or 26 Ch at the urology department of NUZ KB "RJD-Medicine", Krasnoyarsk, Russia, from September 2021 to March 2023, was carried out. Factors that could affect the efficiency and safety of PCNL were analyzed. RESULTS: The mean duration of the procedure was 39.6 +/- 14.4 minutes. The average decrease in hemoglobin level was 5.9 +/- 5.5. Narcotic analgesics were used postoperatively in 17.5% (7) of patients. The mean length of stay was 4.7 +/- 1.1 days. Transient fever was observed in 4 (10%) cases. In one case, an exacerbation of chronic pyelonephritis developed. There were no cases of significant bleeding during the PCNL, and no patients required blood transfusion. CONCLUSIONS: Our results confirm that totally tubeless PNL is a safe alternative to standard procedure and is not associated with an increased risk of early postoperative complications. This technique is efficient and safe for kidney stones and may be recommended for a select group of patients.

Association between DCP levels and kidney stone prevalence in US female adults based on NHANES data.

Our study aimed to evaluate the correlation between levels of 2,4-DCP(2,4-Dichlorophenol) and 2,5-DCP(2,5-Dichlorophenol) and the prevalence of kidney stones in US female adults. Participants were chosen from the National Health and Nutrition Examination Survey database, spanning the years 2007-2016. Dose-response curves were analyzed using logistic regression, subgroup analyses, and other statistical methods to evaluate the relationship between 2,4-DCP and 2,5-DCP levels and the prevalence of kidney stones. The final study included 3220 participants aged over 20 years, with 252 females reporting a history of kidney stones. After accounting for all interfering variables, we found that every 0.1 ug/ml increase in 2.4-DCP correlated with a 1% rise in kidney stone prevalence (OR = 1.01, 95% CI 1.00, 1.01), whereas the same increase in 2.5-DCP was linked to a 27% growth in prevalence (OR = 1.27, 95% CI 1.01, 1.61). Sensitivity analysis was performed by triangulating 2,4-DCP and 2,5-DCP levels. The dose-response curves demonstrated a linear positive relationship between 2,4-DCP and 2,5-DCP levels and the risk of stone development. Our findings indicate a positive correlation between 2,4-DCP and 2,5-DCP levels and the prevalence of kidney stones in US female adults. This association is of clinical significance; however, a direct causal relationship cannot be definitively established.

A prospective case-control study on the evaluation of oxidative stress in renal stone formers.

Association of increased oxidative stress (OS) with the pathophysiology of renal stone formation has not been explored greatly in the field of urolithiasis. In this prospective case-control study, we measured 24-h urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in patients with urolithiasis and compared them with matched healthy controls. We also measured 24-h urinary uric acid, calcium, oxalate, and citrate levels in patients with renal stone disease and studied their relation with urinary 8-OHdG levels. Seventy-five cases of renal stone disease and 75 well-matched controls were included. Median 24-h urinary 8-OHdG levels were significantly higher in cases compared to controls (7.6 vs. 3.7 µg/g of creatinine; p < 0.000). Receiver-operating curve (ROC) analysis for 8-OHdG between cases and controls revealed an area under the curve of 0.90. At 8-OHdG (µg/g of creatinine) value of 5 or more, a sensitivity and a specificity of 84% each were obtained. A positive correlation between 8-OHdG (µg/g of creatinine) and 24-h urinary oxalate level was noted (r = 0.461, p = 0.000). No correlation between 8-OHdG (µg/g of creatinine) and other variables was noted. On multivariate linear regression analysis, we noted 24-h urinary oxalate levels to be an independent predictor of urinary 8-OHdG levels. OS is significantly higher in patients with renal stone diseases compared to healthy controls. Urinary oxalate levels were significantly correlated with urinary 8-OHdG levels.

Correlation research demonstrates that an inflammatory diet is a risk factor for calcium oxalate renal stone formation.

BACKGROUND AND AIMS: Previous studies have demonstrated associations between the Dietary Inflammatory Index (DII®), an analytical tool which evaluates the inflammatory potential of the diet according to the pro- and anti-inflammatory properties of its components, and renal stone formation. However, these have not comprehensively addressed important parameters such as stone type, gender, DII scores in stone formers (SFs) and healthy controls (Cs) and associations of DII with urine and blood chemistries. These were adopted as the survey parameters for the present study, the purpose of which was to test whether the contributory role of an inflammatory diet on stone formation could be further confirmed. METHODS: 97 calcium oxalate (CaOx) SFs and 63 Cs, matched for age and gender each completed a semi-quantitative food frequency questionnaire from which nutrient composition was computed. These data were used to calculate the DII® score. To control the effect of energy intake, energy-adjusted DII scores were calculated per 1000 kcal consumed (E-DII™). A single blood sample and two consecutive overnight (8h) urine samples were collected from a subset (n = 59 SFs and n = 54 Cs) of the overall number of particpants (n = 160). These were analysed for renal stone risk factors. Data were analysed using regression models fit in R software. RESULTS: E-DII scores were found to fit the data better than DII, so they were used throughout. E-DII scores were significantly more positive (more pro-inflammatory) in SFs than in controls in the combined gender group (-0.34 vs. -1.73, p < 0.0001) and separately in males (-0.43 vs. -1.78, p = 0.01) and females (-0.26 vs. - 1.61, p = 0.05). In blood, a significant negative correlation was seen between E-DII and HDL cholesterol. In urine significant positive correlations were seen between E-DII and each of calcium (ρ = 0.25, p = 0.02), phosphate (ρ = 0.48, p < 0.001), magnesium (ρ = 0.33, p < 0.0001) and uric acid (ρ = 0.27, p = 0.004) concentrations. A significant negative correlation was seen between E-DII and urinary volume ρ = -0.27, p = 0.003). There was no correlation between E-DII scores and the relative supersaturations of urinary CaOx, calcium phosphate (brushite) and uric acid. CONCLUSIONS: Our findings provide hitherto unreported quantitative evidence in support of the notion that the diet of calcium oxalate renal stone patients is significantly more pro-inflammatory than that of healthy controls.