Urolithiasis Research Articles

Comparison of laparoscopic-assisted flexible ureteroscopic lithotripsy with percutaneous nephrolithotripsy and flexible ureteroscopy lithotripsy: a case-control study and meta-analysis.

This study aims to compare the differences in stone clearance rate, infection rate, and bleeding risk among laparoscopic-assisted flexible ureteroscopic lithotripsy (LAFUL), percutaneous nephrolithotripsy (PCNL), and flexible ureteroscopic lithotripsy (FUL) through case-control studies and meta-analysis, to evaluate the safety and effectiveness of LAFUL. 1. Through systematic literature search, clinical studies related to LAFUL, PCNL, and FUL were screened, and data on stone clearance rate, infection rate, and bleeding events were collected and analyzed for three groups of patients, followed by meta-analysis. 2. Data of patients who met the single center inclusion criteria and received LAFUL (40 cases), PCNL (40 cases, FUL), and FUL (40 cases) treatments for kidney stones from January 2021 to December 2023 were collected. Using a case-control study method, relevant clinical data were analyzed using SPSS 26.0 software. A total of 31 studies involving 2974 patients were included. The results of case-control analysis showed the stone clearance rate in the LAFUL group (F = 225.19, P < 0.001) and the positive rate of postoperative urine bacterial culture (X2 = 4.558, P = 0.033). The results of meta-analysis showed the stone clearance rate (rate = 0.986, 95% CI 0.964-0.999) and blood transfusion rate (rate = 0, 95% CI 0-0.012) in the LAFUL group. LAFUL shows potential in improving the stone clearance rate and reducing the risk of postoperative infection and bleeding, suggesting it may have certain advantages in the treatment of renal calculi.

Total tubeless percutaneous nephrolithotomy without retrograde insertion of a ureteral catheter for the treatment of kidney stone patients without hydronephrosis: a randomized controlled trial.

To evaluate the safety and efficacy of total tubeless percutaneous nephrolithotomy (PCNL) without retrograde insertion of a ureteral catheter for the treatment of kidney stone patients without hydronephrosis. This prospective randomized controlled study at a tertiary care medical center was conducted from August 2019 to April 2023. Kidney stone patients diagnosed by computed tomography (CT) without significant hydronephrosis were randomly assigned to two groups: total tubeless PCNL without retrograde insertion of a ureteral catheter (group 1) and traditional PCNL (group 2). The primary endpoint was postoperative complications, while the secondary endpoints included the stone-free rate (SFR), operative time, length of postoperative hospital stay, and medical costs. A total of 99 patients were recruited, including 50 patients in group 1 and 49 patients in group 2. There were no significant differences in postoperative complications and SFR between the two groups (P > 0.05). However, relative to group 2, patients in group 1 had significantly shorter operative time (58.5 ± 25.39min vs. 82.98 ± 26.02min, P < 0.001) and length of postoperative hospital stay (1.98 ± 1.72days vs. 4.39 ± 2.95days, P < 0.001), as well as significantly lower medical costs (3190.30 ± 590.58 dollars vs. 3552.78 ± 967.79 dollars, P = 0.03). Total tubeless PCNL without retrograde insertion of a ureteral catheter for the treatment of kidney stone patients without hydronephrosis is safe and effective for urologists with extensive experience in PCNL. chictr.org.cn identifier, ChiCTR2000040884, date of registration: 13/12/2020, retrospectively registered.

Air pollutants, residential greenspace, and the risk of kidney stone disease: a large prospective cohort study from the UK Biobank.

The epidemiological evidence regarding the correlation between air pollution, residential greenspace, and the risk of kidney stone disease (KSD) is limited, with no large-scale prospective studies conducted on this relationship. We conducted a large-scale prospective study from the UK Biobank to explore the correlation between air pollution, residential greenspace, and the risk of KSD. This study included 419,835 UK Biobank participants who did not have KSD at baseline. An air pollution score was derived through the summation of concentrations for five air pollutants, including particulate matter (PM) with aerodynamic diameter ≤2.5 μm (PM2.5), ranging from 2.5 to 10 μm (PM2.5-10), ≤10 μm (PM10), nitrogen dioxide (NO2), and nitrogen oxides (NOx). Various covariates were adjusted for in Cox proportional hazard regression to evaluate the risk of KSD associated with air pollution score, single air pollutant, and residential greenspace. During a follow-up period of 12.7 years, 4503 cases of KSD were diagnosed. Significant associations were found between KSD risk and air pollution score (HR: 1.08, 95% CI: 1.03-1.13), PM2.5 (1.06, 1.02-1.11), PM10 (1.04, 1.01-1.07), NO2 (1.09, 1.02-1.16), NOx (1.08, 1.02-1.11), greenspace buffered at 300 m (0.95, 0.91-0.99), and greenspace buffered at 1000 m (0.92, 0.86-0.98) increase per interquartile range (IQR). PM2.5 and NO2 reductions may be a key mechanism for the protective impact of residential greenspace on KSD (P for indirect path < 0.05). Prolonged exposure to air pollution was correlated with a higher risk of KSD, while residential greenspace exhibits an inverse association with KSD risk, partially mediated by the reduction in air pollutants concentrations. These findings emphasize the significance of mitigating air pollution and maintaining substantial greenspace exposure as preventive measures against KSD.

Integrating 3D technology with the Sampaio classification for enhanced percutaneous nephrolithotomy in complex renal calculi treatment.

To investigate the safety and efficacy of percutaneous nephrolithotomy (PCNL) in the treatment of complicated renal calculi by integrating three-dimensional (3D) computed tomography (CT) reconstruction with the Sampaio classification of the renal collecting system. Sixty-four consecutive patients with complex kidney calculi who underwent PCNL between January 2019 and October 2023 were retrospectively analyzed and divided into experimental group (3D printing) and control group (CT imaging) according to their willingness to pay for 3D imaging. Both groups underwent preoperative CT urography. The Digital Imaging and Communications (DICOM) in Medicine data of the experimental group from CT imaging were used for 3D reconstruction and model printing. Then, the Sampaio classification system was used to design the puncture channel and develop a surgical strategy. The 3D-printed models of the experimental group successfully displayed the Sampaio classification system. There was no significant difference in the baseline parameters between the groups. Compared with the control group, the experimental group exhibited significant improvements in the puncture time, number of puncture needles, number of puncture channels, target calyx consistency, number of first puncture channels, and stone clearance. There were no significant differences in the total operative time, decrease in the hemoglobin level, length of hospital stay, and postoperative complications between the groups. Integration of 3D technology with the Sampaio classification of the renal collecting system can enhance the preoperative evaluation and planning of percutaneous renal access. This approach allows a more precise method of PCNL for treating complex renal calculi.

Optimization of Plant Oxalate Quantification and Generation of Low-Oxalate Maize (Zea mays L.) through O7 Overexpression.

Oxalate, the simplest dicarboxylic acid, is a prevalent antinutrient that chelates with various metals and can lead to the formation of kidney stones in humans. The accurate detection of the oxalate concentration in food and the cultivation of low-oxalate crops are important for enhancing public health. In this study, we established a high-throughput and highly sensitive technique for oxalate detection using ultra-high-performance liquid chromatographic-triple quadrupole tandem mass spectrometry (UPLC-QqQ-MS/MS). Additionally, we overexpressed the gene O7, which encodes oxalyl-CoA synthetase in the maize oxalate degradation pathway, resulting in O7-OE lines. By employing the UPLC-QqQ-MS/MS method to measure oxalate levels in these transgenic lines, we observed that the oxalate content in the kernels of O7-OE lines was reduced by approximately 43%, with a concurrent increase in some micronutrients such as zinc. Importantly, the transgenic maize showed normal seed storage compound accumulation or other agronomic characteristics. In summary, we developed a high-throughput detection method that advances oxalate measurement. Furthermore, by generating new maize germplasm with diminished oxalate, our work offers potential health advantages to consumers.

Mini-percutaneous nephrolithotomy vs flexible ureteroscopy for 1-2 cm lower pole renal stones: a randomised controlled trial.

To compare the safety and efficacy of flexible ureteroscopy (f-URS) and ambulatory tubeless mini-percutaneous nephrolithotomy (mini-PCNL) in the treatment of 1-2 cm lower calyceal renal stones. Patients who underwent f-URS and mini-PCNL for the treatment of 1-2 cm lower calyceal renal stones between October 2020 and November 2023 were evaluated in a randomised controlled trial. A total of 72 patients were included in the study. All patients underwent a computed tomography renal colic scan preoperatively, on postoperative Day 1 (POD 1), and at 3 months follow-up. We compared perioperative outcomes, including operative time and hospital stay. Additionally, we evaluated follow-up outcomes, such as the stone-free rate (SFR) and complications. All patients were discharged home on the same operative day. There were no significant differences in preoperative baseline data between the two surgical groups. A significantly longer median operative time was reported in the mini-PCNL group (P = 0.04). The median hospital stay was 5 h and 4 h in the mini-PCNL and f-URS groups, respectively (P = 0.14). On POD 1, the SFR, defined as the absence of residual fragments measuring 0 cm, was 50% for mini-PCNL vs 11.1% for f-URS (P < 0.001). When a total cut-off of <4 cm was utilised, the SFR was 75% in the mini-PCNL group vs 22.2% in the f-URS cohort (P < 0.001). At 3 months follow-up, the SFR remained favourable for mini-PCNL at 72.2% vs 37.1% for f-URS (P = 0.003), with a cut-off of 0 cm, and it increased to 86.1% for mini-PCNL vs 65.7% for f-URS (P = 0.04) when a total cut-off of <4 cm was applied. There was no significant difference in postoperative complications between the two groups. Two patients (5.7%) in the f-URS group required re-treatment. Ambulatory tubeless mini-PCNL and f-URS are effective treatment options for 1-2 cm lower calyceal renal stones. Both techniques have a comparable hospital stay and complication rates, with a significantly better SFR with mini-PCNL.

Association of dietary live microbe intake with kidney stone disease in US adults: a real-world cross-sectional study.

Kidney stone disease (KSD) is a common urological condition linked with hypertension, chronic kidney disease, and other health issues. Although the gut microbiome has a notable association with KSD formation, the relationship between dietary live microbes and KSD risk remains underexplored. This study utilized data from the NHANES surveys conducted between 2007 and 2016 to analyze the association between dietary live microbe intake and KSD. Dietary intake data were obtained through 24-h dietary recall interviews conducted by trained professionals. Participants were categorized into three groups based on Sanders' classification system of dietary live microbe intake: low, medium, and high. The intake levels were determined by estimating the live microbe content in foods. Weighted logistic regression analysis was employed to account for the complex survey design and to assess the impact of different levels of live microbe intake on KSD risk. A total of 20,380 participants were included in the study. Participants with low, medium, and high dietary microbe intake represented 33, 39, and 28% of the cohort, respectively. The adjusted odds ratios (ORs) for KSD were 0.78 (95% CI, 0.65-0.93) in the high dietary live microbe group compared to the low group (p < 0.05). Subgroup analyses revealed no significant interactions between dietary live microbe intake and gender, age, BMI, hypertension, or diabetes status. Higher dietary live microbe intake group may be associated with a reduced risk of KSD. Further prospective studies are necessary to validate these findings and to elucidate the specific mechanisms and optimal intake levels of dietary microbes.

Application value of surgical navigation system based on deep learning and mixed reality for guiding puncture in percutaneous nephrolithotomy: a retrospective study.

This study was conducted to investigate the clinical value of a navigation system based on deep learning and mixed reality for the treatment of kidney stones with percutaneous nephrolithotomy (PNL), and to improve its theoretical basis for the treatment of kidney stones. The data of 136 patients with kidney stones from October 2021 to December 2023 were retrospectively analyzed. All patients underwent PNL, and were categorized into a control group (Group 1) and a surgical navigation group (Group 2) according to puncture positioning method. Preoperative computed tomography (CT) was performed in both groups. In group 1, procedures were performed under standard ultrasound guidance. PNL was performed with navigation system fused with ultrasound to guide percutaneous puncture in group 2. The baseline information and procedural characteristics of both groups were compared. PNL was successfully performed in both groups. No significant difference was found in the baseline date between the two groups. In group 2, real-time ultrasound images could be accurately matched with CT images with the aid of navigation system. The success rate of single puncture, puncture time, and decrease in hemoglobin were significantly improved in group 2 compared to group 1. (p < 0.05). The application of navigation system based on deep learning and mixed reality in PNL for kidney stones allows for real-time intraoperative navigation, with acceptable accuracy and safety. Most importantly, this technique is easily mastered, particularly by novice surgeons in the field of PNL.

Current Trends and Technological Advancements in the Use of Oxalate-Degrading Bacteria as Starters in Fermented Foods—A Review

Nephrolithiasis is a medical condition characterized by the existence or development of calculi, commonly referred to as stones within the renal system, and poses significant health challenges. Calcium phosphate and calcium oxalate are the predominant constituents of renal calculi and are introduced into the human body primarily via dietary sources. The presence of oxalates can become particularly problematic when the delicate balance of the normal flora residing within the gastrointestinal tract is disrupted. Within the human gut, species of Oxalobacter, Lactobacillus, and Bifidobacterium coexist in a symbiotic relationship. They play a pivotal role in mitigating the risk of stone formation by modulating certain biochemical pathways and producing specific enzymes that can facilitate the breakdown and degradation of oxalate salts. The probiotic potential exhibited by these bacteria is noteworthy, as it underscores their possible utility in the prevention of nephrolithiasis. Investigating the mechanisms by which these beneficial microorganisms exert their effects could lead to novel therapeutic strategies aimed at reducing the incidence of kidney stones. The implications of utilizing probiotics as a preventive measure against kidney stone formation represent an intriguing frontier in both nephrology and microbiome research, meriting further investigation to unlock their full potential.

Prevention and Management of Urolithiasis With Parsley and Barley Among the Hail Population, Saudi Arabia: Is It Fact or Not?

Urolithiasis is one of the most common urinary tract diseases. It is a multifactorial condition involving both environmental and metabolic aspects. Dietary changes and lifestyle modifications are crucial for managing and preventing urolithiasis. Barley and parsley have been utilized as a complementary treatment to manage urolithiasis, which may be helpful in managing and preventing this disease. This was a community-based cross-sectional study conducted to determine the effects of parsley and barley in managing urolithiasis among the population of Hail, Saudi Arabia by an electronic questionnaire. All responses were kept confidential. Statistical analyses were conducted using SPSS version 22 (Chicago, IL: SPSSInc.). A total of 395 participants completed the questionnaire, with ages ranging from 18 years to more than 60 years; nearly half of them were females. Only 37 (9.4%) had a history of renal disease but 182 (46.1%) had a family history of renal stones. Regarding the frequency of barley and parsley used in the management of renal stones, 162 (41%) respondents used barley, while 176 (44.6%) of them used parsley to treat or prevent kidney stones. Factors associated with the use of barley and parsleyin the management of renal stones were older age, female gender, non-healthcare staff, those with renal disease history, and family history of renal stones. The results showed that among the Hail population, non-conventional therapies are more commonly used for treating renal stones than medical treatment. There were multiple factors associated with using barley and parsley to manage urolithiasis. Additional research is needed to gain a clearer understanding of the safety and effectiveness of non-conventional therapies, such as barley and parsley, in managing urolithiasis.

Preventive Impacts of Black Tea, Green Tea and Bidens pilosa on Renal Stone Formation in Rats: Antioxidant and Anti-inflammatory Pathways.

Preventive Impacts of Black Tea, Green Tea and Bidens pilosa on Renal Stone Formation in Rats: Antioxidant and Anti-inflammatory Pathways.

Bidirectional Impact of Varying Severity of Acute Kidney Injury on Calcium Oxalate Stone Formation

Introduction: Acute kidney injury (AKI) is a prevalent renal disorder. The occurrence of AKI may promote the formation of renal calcium oxalate stones by exerting continuous effects on renal tubular epithelial cells (TECs). We aimed to delineate the molecular interplay between AKI and nephrolithiasis. Methods: A mild (20 min) and severe (30 min) renal ischemia-reperfusion injury model was established in mice. Seven days after injury, calcium oxalate stones were induced using glyoxylate (Gly) to evaluate the impact of AKI on the formation of kidney stones. Transcriptome sequencing was performed on TECs to elucidate the relationship between AKI severity and kidney stones. Key transcription factors (TFs) regulating differential gene transcription levels were identified using motif analysis, and pioglitazone, ginkgetin, and fludarabine were used for targeted therapy to validate key TFs as potential targets for kidney stone treatment. Results: Severe AKI led to increased deposition of calcium oxalate crystals in renal, impaired kidney function, and upregulation of kidney stone-related gene expression. In contrast, mild AKI was associated with decreased crystal deposition, preserved kidney function, and downregulation of similar gene expression. Transcriptomic analysis revealed that genes associated with inflammation and cell adhesion pathways were significantly upregulated after severe AKI, while genes related to energy metabolism pathways were significantly upregulated after mild AKI. An integrative bioinformatic analysis uncovered a TF regulatory network within TECs, pinpointing that PKNOX1 was involved in the upregulation of inflammation-related genes after severe AKI, and inhibiting PKNOX1 function with pioglitazone could simultaneously reduce the increase of calcium oxalate crystals after severe AKI in kidney. On the other hand, motif analysis also revealed the protective role of STAT1 in the kidneys after mild AKI, enhancing the function of STAT1 with ginkgetin could reduce kidney stone formation, while the specific inhibitor of STAT1, fludarabine, could eliminate the therapeutic effects of mild AKI on kidney stones. Conclusion: Inadequate repair of TECs after severe AKI increases the risk of kidney stone formation, with the upregulation of inflammation-related genes regulated by PKNOX1 playing a role in this process. Inhibiting PKNOX1 function can reduce kidney stone formation. Conversely, after mild AKI, effective cell repair through upregulation of STAT1 expression can protect TEC function and reduce stone formation, and activating STAT1 function can also achieve the goal of treating kidney stones.

Insulin Resistance in Hypercalciuric Calcium Kidney Stone Patients

Rational and ObjectiveDiabetes and uric acid kidney stones are strongly associated. Patients with calcium kidney stones also have higher risk of developing diabetes compared to non-kidney stone patients yet this has not been further investigated. We aimed to characterize insulin resistance in calcium kidney stone patients. Study DesignObservational Setting & PopulationThis study was performed in the University of Chicago Clinical Research Center. Kidney stone patients (N=42) were selected for having idiopathic hypercalciuria and calcium stones with no other medical conditions and controls (N=27) were healthy. ExposuresAll participants presented to the Clinical Research Center in a fasting state and at least 2 timed fasting blood and urine were collected prior to a fixed breakfast. Six additional timed blood and urine collections were performed after breakfast. OutcomesWe compared fasting and fed indices of insulin resistance between the groups. Analytic ApproachWe used t-tests and multivariable linear regression models. A sensitivity analysis removing all patients who had ever been on a thiazide diuretic was also performed. ResultsIn separate multivariable linear models, kidney stone patients had higher fasting serum insulin (24 (3 to 46pmol/L), p=0.03) and higher homeostatic model of insulin resistance (HOMA-IR) (1.0 (0.2 to 1.8), p=0.02). In separate multivariable linear models, kidney stone patients had higher fed serum glucose (10 (2 to 18mg/dL), p=0.01). Results were similar in a sensitivity analysis removing all patients who had ever been on a thiazide diuretic. There were no differences in urine composition based on HOMA-IR levels. LimitationsSingle institution. Small sample size limited subanalyses by different calcium stone types. ConclusionsCalcium kidney stone patients without diabetes or other medical conditions demonstrated signs of insulin resistance compared to healthy matched controls.

Unveiling the Burden of Nephrolithiasis in Low- and Lower-Middle Income Countries: A Review on Its Presentation, Risk Factors, Treatment Practices, and Future Directions

Background: Nephrolithiasis, or kidney stone disease, presents a significant global health burden, with global incidence rates and treatment practices varying widely. This study aims to discuss the epidemiology, risk factors, treatment modalities, and challenges for nephrolithiasis in the lower half of the World Bank rankings; that is, in low- and lower-middle-income countries. Methods: A comprehensive literature review was conducted using PubMed for each country on the list, focusing on studies published from January 2000 onwards and reporting data on prevalence, risk factors, treatment practices, and economic implications. Results: Nephrolithiasis represents a significant burden for healthcare systems, with noteworthy geographical variability in prevalence possibly dependent on socioeconomic status and gender. Risk factors include dietary habits, climate, pollution, and infectious diseases. Treatment practices in some regions still rely on open surgery due to limited access to advanced endourological techniques, while other regions demonstrate high proactivity in research. The burden is exacerbated by inadequate healthcare infrastructure and training. Conclusions: Addressing nephrolithiasis in challenging economic circumstances requires targeted interventions, including improved access to modern treatment methods, enhanced training for healthcare professionals, and better socioeconomic and environmental conditions. Future research should focus on region-specific strategies and the development of sustainable healthcare solutions.

HR-pQCT reveals marked trabecular and cortical structural deficits in women with pregnancy and lactation associated osteoporosis (PLO).

Pregnancy and lactation associated osteoporosis (PLO) is a rare presentation of early-onset osteoporosis characterized by low trauma, spontaneous fractures during late pregnancy/lactation. Herein, we report areal BMD (aBMD) by DXA and volumetric BMD (vBMD), microarchitecture and strength at the distal radius and tibia by HR-pQCT in 59 women with PLO - in comparison to both healthy premenopausal Controls (n= 28) and premenopausal women with idiopathic osteoporotic fractures not associated with pregnancy/lactation (Non-PLO IOP;n= 50). Women with PLO (aged 34 ± 6yrs) had a more severe clinical presentation than Non-PLO IOP: 80% had vertebral and 92% had multiple fractures (P<.001). They had lower DXA aBMD at all sites vs Controls (all P<.001) and non-PLO IOP (all P<.05). By HR-pQCT, PLO had deficits in all radial/tibial density and most microarchitecture parameters, and lower bone strength than Controls (all P<.001). Compared to non-PLO IOP, PLO had lower total and trabecular density at radius and tibia (all P≤.01) and significant deficits in trabecular microstructure and cortical thickness at the radius only. We studied PLO subgroups with clinical factors potentially related to bone physiology: Within PLO, women with vertebral fractures had lower spine aBMD and higher tibial cortical porosity but were otherwise structurally similar to the nonvertebral group. Those with prior heparin exposure had larger bone size and trabecular area, and those with renal stones had smaller bone size and lower 1/3radius aBMD. We also compared groups based on postpartum timing: Recent PLO (n= 25) evaluated ≤12M postpartum, before expected recovery of pregnancy/lactation bone loss, had significantly lower aBMD than Distant PLO (n= 34) evaluated >12M postpartum. However, radial/tibial HR-pQCT measures did not differ, suggesting pre-existing and/or persistent structural deficits. This structural study increases our mechanistic understanding of the severe bone fragility presentation that characterizes PLO and also highlights areas of potential mechanistic heterogeneity that require additional investigation.

Efficacy of an erector spinae plane block for renal colic: a systematic review and meta-analysis

Background and aimThe passage of kidney stones through the ureter creates renal colic, a severe visceral abdominal pain. Renal colic is typically managed with non-steroidal anti-inflammatory drugs and opioids. Yet,...

"Modified Lithotomy Position RIRS For Infectious Staghorn Renal Calculi in a Patient at Extremely High Risk of Thrombosis: A Case Report"

"Modified Lithotomy Position RIRS For Infectious Staghorn Renal Calculi in a Patient at Extremely High Risk of Thrombosis: A Case Report"

Serial manual bolus irrigation leads to critical intrarenal pressures during flexible ureterorenoscopy - time to abandon this manoeuvre.

To characterise the effect of solitary and serial manual bolus irrigations on intrarenal pressures (IRPs) and observe the clinical consequences. A pressure guidewire was used for IRP measurement during routine flexible ureterorenoscopy for management of renal stone disease, including manual bolus irrigation when required to maintain vision. The fluid bolus was either as a solitary manual bolus or a series of manual boluses in quick succession. The pre-bolus, maximal and difference between IRPs were calculated. A total of 50 procedures in 46 patients were analysed. In all, 68 solitary manual boluses and 38 serial manual boluses were observed to have been undertaken during these procedures. After a solitary manual bolus, the median (standard deviation [SD], range) increase in IRP was 22.4 (34.0, 0.1-160.8) mmHg, and the mean (SD, range) maximum IRP was 46.1 (41.7, 15.8-190.0) mmHg, with elevated IRPs persisting for a median (range) duration of 19 (4-66) s. After serial manual boluses, the median (SD, range) rise in IRP was 58.4 (64.7, 10.2-242.84) mmHg and the mean (SD, range) maximum IRP reached was 100.8 (69.7, 34.3-303.5) mmHg. The elevated IRPs endured for a median (range) of 42 (9-121 s; P < 0.01 in all comparisons), suggesting a much greater elevation of IRP with instances where serial bolus irrigation was undertaken. Manual bolus irrigation, both solitary but particularly serial boluses, produces significant rises in IRP and could logically result in pyelovenous backflow and sepsis. We suggest that this manoeuvre should be avoided to reduce complications during ureterorenoscopy.

Macroscopic hematuria-associated severe acute kidney injury triggered by kidney stone formation in a patient with thin basement membrane and no history of microscopic hematuria.

Macroscopic hematuria (MH)-associated acute kidney injury (AKI) is a rare condition that causes acute tubular damage due to severe glomerular bleeding with MH. A 66-year-old Japanese woman with no significant past medical history was referred for severe kidney injury with oliguric MH. Her prior medical checkup results showed no occult blood in her urine. Seven days earlier, she had experienced transient severe acute right lumbar back pain. On admission, her serum urea nitrogen was 147mg/dL, serum creatinine (sCr) 18.3mg/dL, urinary red blood cells (RBCs) > 100/hpf, urinary protein 28.8g/gCr, with no hydronephrosis in either kidney, but two stones were found in the right kidney and right ureteropelvicjunction. At the start of her hemodialysis, the patient was treated with high-dose steroids because of suspected rapidly progressive glomerulonephritis. A renal biopsy of the left kidney showed acute tubular injury with massive RBC casts filling the tubular lumen. Glomerulitis was not detected, but electron microscopy revealed diffuse glomerular thin basement membrane (TBM). Despite immediate steroid discontinuation, the patient's renal function and MH improved, and she was weaned from hemodialysis. The stones resolved 2months after onset, but microscopic hematuria persisted for 7months post-onset. The sCr level was fixed at 1.1mg/dL 20months post-onset. This is the first report of MH-AKI in a TBM without the risk of MH-AKI development, such as bleeding tendency or iron overload. In this TBM, a colic attack of the renal urinary tract induced glomerular bleeding, and intolerance to hematuria may have caused severe tubular damage.

Selenium participates in the formation of kidney stones by alleviating endoplasmic reticulum stress and apoptosis of renal tubular epithelial cells

ABSTRACT Objectives: To investigate the role of selenium and selenium-containing proteins in the etiology and pathogenesis of kidney stones. Methods: The HK-2 cell line was subjected to supersaturation oxalate treatment to establish an in vitro model of calcium oxalate kidney stones, while SD rats were administered with ethylene glycol to establish an in vivo model of calcium oxalate kidney stones. qPCR analysis was employed to investigate the alterations in selenoproteins within the models, and subsequently, genes exhibiting significant changes were identified. Subsequently, based on the functions of these genes, their regulatory effects on endoplasmic reticulum stress (ERS) and apoptosis during the disease progression were examined both in HK-2 cells and rat kidneys. Finally, Selenomethionine (SeMet) supplementation was introduced to explore its therapeutic potential for kidney stone management. Results: The involvement of Selenoprotein K in the pathogenesis of calcium oxalate kidney stone disease has been confirmed, exhibiting significant alterations. Manipulation of its expression levels through overexpression and knockdown techniques resulted in a corresponding reduction or increase in oxidative stress, ERS, and apoptosis within renal tubular epithelial cells. SelK regulates ERS and apoptosis by controlling the IRE1-ASK1-JNK pathway. In addition, SeMet treatment, which contains selenium, effectively reduced the levels of oxidative stress, ERS, and apoptosis in vivo and in vitro models, thereby alleviating tubular epithelial cell damage and reducing the formation of kidney stones in experimental rats. Discussion: Selenium is involved in the occurrence and development of kidney stones by regulating oxidative damage to renal tubular epithelial cells. The results suggest that dietary selenium supplementation in daily life may be of great significance for the prevention and treatment of kidney stones.