Epidemiology of stone disease across the world

Evaluation of Coscinium fenestratum (Goetgh.) Colebr. stem extracts for urolithiasis and quantification of bioactive alkaloids to validate the traditional claims

Coscinium fenestratum (Goetgh.) Colebr. is widely used for urinary disorders and kidney stones by ethnic communities in southern India. The species is documented in various ancient Indian Ayurvedic literatures having therapeutic use in 'Ashmari' i.e., urolithiasis. The present study aims at validation of in-vitro anti-urolithiatic potential of various extracts of C. fenestratum stem along with identification and quantification of major bioactive alkaloids, i.e., berberine and palmatine through HPTLC and LC-MS/MS. Water extract showed maximum anti-urolithiatic activity which on further kinetic analysis, showed concentration dependent inhibitory delay in nucleation and aggregation of calcium oxalate crystals. Berberine and palmatine were quantified with maximum content in methanolic extract (0.478 ± 0.003 and 0.0358 ± 0.001) followed by chloroform and petroleum ether extracts. The study validates ethnobotanical use of C. fenestratum as anti-urolithiatic agent. Further, species can also be explored as a substitute for Berberis spp. for the alkaloid metabolites i.e., berberine and palmatine.

Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones

BACKGROUND

Nephrolithiasis is a common urological disease worldwide. Extracorporeal shock wave lithotripsy (ESWL) has been used for the treatment of renal stones since the 1980s, while retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) are newer, more invasive treatment modalities that may have higher stone-free rates. The complications of RIRS and PCNL have decreased owing to improvement in surgical techniques and instruments. We re-evaluated the best evidence on this topic in an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the effects of extracorporeal shock wave lithotripsy compared with percutaneous nephrolithotomy or retrograde intrarenal surgery for treating kidney stones.

SEARCH METHODS

We performed a comprehensive search in CENTRAL, MEDLINE, Embase, and ClinicalTrials.gov with no restrictions on language or publication status. The latest search date was 6 December 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that compared ESWL with PCNL or RIRS for kidney stone treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies, extracted data, and assessed risk of bias. Our primary outcomes were treatment success rate at three months (defined as residual fragments smaller than 4 mm, or as defined by the study authors), quality of life (QoL), and complications. Our secondary outcomes were retreatment rate, auxiliary procedures rate, and duration of hospital stay. We performed statistical analyses using a random-effects model and independently rated the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 31 trials involving 3361 participants (3060 participants completed follow-up). Four trials were only available as an abstract. Overall mean age was 46.6 years and overall mean stone size was 13.4 mm. Most participants (93.8%) had kidney stones measuring 20 mm or less, and 68.9% had lower pole stones. ESWL versus PCNL ESWL may have a lower three-month treatment success rate than PCNL (risk ratio [RR] 0.67, 95% confidence interval [CI] 0.57 to 0.79; I2 = 87%; 12 studies, 1303 participants; low-certainty evidence). This corresponds to 304 fewer participants per 1000 (397 fewer to 194 fewer) reporting treatment success with ESWL. ESWL may have little or no effect on QoL after treatment compared with PCNL (1 study, 78 participants; low-certainty evidence). ESWL probably leads to fewer complications than PCNL (RR 0.62, 95% CI 0.47 to 0.82; I2 = 18%; 13 studies, 1385 participants; moderate-certainty evidence). This corresponds to 82 fewer participants per 1000 (115 fewer to 39 fewer) having complications after ESWL. ESWL versus RIRS ESWL may have a lower three-month treatment success rate than RIRS (RR 0.85, 95% CI 0.78 to 0.93; I2 = 63%; 13 studies, 1349 participants; low-certainty evidence). This corresponds to 127 fewer participants per 1000 (186 fewer to 59 fewer) reporting treatment success with ESWL. We are very uncertain about QoL after treatment; the evidence is based on three studies (214 participants) that we were unable to pool. We are very uncertain about the difference in complication rates between ESWL and RIRS (RR 0.93, 95% CI 0.63 to 1.36; I2 = 32%; 13 studies, 1305 participants; very low-certainty evidence). This corresponds to nine fewer participants per 1000 (49 fewer to 48 more) having complications after ESWL.

AUTHORS' CONCLUSIONS

ESWL compared with PCNL may have lower three-month success rates, may have a similar effect on QoL, and probably leads to fewer complications. ESWL compared with RIRS may have lower three-month success rates, but the evidence on QoL outcomes and complication rates is very uncertain. These findings should provide valuable information to aid shared decision-making between clinicians and people with kidney stones who are undecided about these three options.

Association between hysterectomy and kidney stone disease: results from the National Health and Nutrition Examination Survey 2007-2018 and Mendelian randomization analysis

PURPOSE

Hysterectomy is one of the most common types of gynecological operations and it is associated with numerous postoperative complications. Few studies have reported a definitive association between hysterectomy and kidney stone disease (KSD). This study aimed to explore whether hysterectomy increases the risk of KSD.

METHODS

This is a cross-sectional study that used six continuous cycles of data obtained from the National Health and Nutrition Examination Survey from 2007 to 2018. The correlations between hysterectomy or age at hysterectomy and the prevalence of KSD were assessed using weighted multivariable-adjusted logistic regression. Further, five methods of two-sample Mendelian randomization (MR) were applied to decrease bias and infer causality in the observational study.

RESULTS

After adjusting for potential confounders, hysterectomy (OR: 1.37, 95% CI 1.04-1.81) was found to be positively associated with the prevalence of KSD, whereas age at hysterectomy was found to be negatively associated with the prevalence of KSD (OR: 0.96, 95% CI: 0.94-0.98). In the inverse-variance weighted method, MR analyses suggested that genetically predicted hysterectomy is causally associated with a higher risk of KSD (OR: 11.961, 95% CI 1.12-1.28E2).

CONCLUSIONS

Hysterectomy could increase the risk of KSD. Younger age at hysterectomy is associated with a higher risk of KSD. Further prospective cohort studies with larger sample sizes and longer follow-up times are needed.

Overexpression of sirtuin 1 attenuates calcium oxalate-induced kidney injury by promoting macrophage polarization

Sirtuin 1 (SIRT1) protein is involved in macrophage differentiation, while NOTCH signaling affects inflammation and macrophage polarization. Inflammation and macrophage infiltration are typical processes that accompany kidney stone formation. However, the role and mechanism of SIRT1 in renal tubular epithelial cell injury caused by calcium oxalate (CaOx) deposition and the relationship between SIRT1 and the NOTCH signaling pathway in this urological disorder are unclear. This study investigated whether SIRT1 promotes macrophage polarization to inhibit CaOx crystal deposition and reduce renal tubular epithelial cell injury. Public single-cell sequencing data, RT-qPCR, immunostaining approaches, and Western blotting showed decreased SIRT1 expression in macrophages treated with CaOx or exposed to kidney stones. Macrophages overexpressing SIRT1 differentiated towards the anti-inflammatory M2 phenotype, significantly inhibiting apoptosis and alleviating injury in the kidneys of mice with hyperoxaluria. Conversely, decreased SIRT1 expression in CaOx-treated macrophages triggered Notch signaling pathway activation, promoting macrophage polarization towards the pro-inflammatory M1 phenotype. Our results suggest that SIRT1 promotes macrophage polarization towards the M2 phenotype by repressing the NOTCH signaling pathway, which reduces CaOx crystal deposition, apoptosis, and damage in the kidney. Therefore, we propose SIRT1 as a potential target for preventing disease progression in patients with kidney stones.

PPARG: A Novel Target for Yellow Tea in Kidney Stone Prevention

Kidney stones are a common urological disorder with increasing prevalence worldwide. The treatment of kidney stones mainly relies on surgical procedures or extracorporeal shock wave lithotripsy, which can effectively remove the stones but also result in some complications and recurrence. Therefore, finding a drug or natural compound that can prevent and treat kidney stones is an important research topic. In this study, we aimed to investigate the effects of yellow tea on kidney stone formation and its mechanisms of action. We induced kidney stones in rats by feeding them an ethylene glycol diet and found that yellow tea infusion reduced crystal deposits, inflammation, oxidative stress, and fibrosis in a dose-dependent manner. Through network pharmacology and quantitative structure-activity relationship modeling, we analyzed the interaction network between the compounds in yellow tea and kidney stone-related targets and verified it through in vitro and in vivo experiments. Our results showed that flavonoids in yellow tea could bind directly or indirectly to peroxisome proliferator-activated receptor gamma (PPARG) protein and affect kidney stone formation by regulating PPARG transcription factor activity. In conclusion, yellow tea may act as a potential PPARG agonist for the prevention and treatment of renal oxidative damage and fibrosis caused by kidney stones.

The altered composition of gut microbiota and biochemical features as well as dietary patterns in a southern Chinese population with recurrent renal calcium oxalate stones

The correlation among gut microbiota, biochemical features, and dietary patterns in recurrent stone formers has been inadequately investigated in the Chinese population. Forty-two patients with calcium oxalate stones (CaOxS group), including 34 recurrent stone formers (RS group), and 40 nonstone healthy subjects (NS group) from Changshu Hospital Affiliated with Soochow University, were prospectively recruited. Food frequency questionnaires were completed by participants, fasting vein blood was extracted, 24-h urine was collected for biochemical detection, and fecal samples were gathered for 16S ribosomal RNA (rRNA) gene sequencing. BMI; serum levels of triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), magnesium, and creatinine; and urine levels of magnesium in stone formers were significantly different from those of controls, and RS patients showed significantly low serum phosphate and high urine phosphate levels. Celery, bamboo shoots, and pickled food were the favored foods of local stone formers. Patients with recurrent stones had altered microbiota composition, with Escherichia, Fusobacterium, and Epulopiscium being the predominant pathogenic genera. The gut microbiota in RS patients had stronger functions in fatty acid and amino acid degradation but weaker functions in their biosynthesis. The pathogenic genera were positively correlated with BMI; serum levels of TGs and creatinine; urine levels of calcium, phosphate, and uric acid (UA); and celery, bamboo shoots, and pickled food intake. The abundance of Escherichia and Fusobacterium and the levels of serum magnesium and creatinine were the most relevant factors associated with stone recurrence and could be validated as biomarkers of recurrence. Our research provides a novel prevention strategy for the recurrence of renal calcium oxalate stones in the Han Chinese population of southern China.

Use of artificial intelligence for sepsis risk prediction after flexible ureteroscopy: a systematic review

INTRODUCTION

flexible ureteroscopy is a minimally invasive surgical technique used for the treatment of renal lithiasis. Postoperative urosepsis is a rare but potentially fatal complication. Traditional models used to predict the risk of this condition have limited accuracy, while models based on artificial intelligence are more promising. The objective of this study is to carry out a systematic review regarding the use of artificial intelligence to detect the risk of sepsis in patients with renal lithiasis undergoing flexible ureteroscopy.

METHODS

the literature review is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The keyword search was performed in MEDLINE, Embase, Web of Science and Scopus and resulted in a total of 2,496 articles, of which 2 met the inclusion criteria.

RESULTS

both studies used artificial intelligence models to predict the risk of sepsis after flexible uteroscopy. The first had a sample of 114 patients and was based on clinical and laboratory parameters. The second had an initial sample of 132 patients and was based on preoperative computed tomography images. Both obtained good measurements of Area Under the Curve (AUC), sensitivity and specificity, demonstrating good performance.

CONCLUSION

artificial intelligence provides multiple effective strategies for sepsis risk stratification in patients undergoing urological procedures for renal lithiasis, although further studies are needed.

Prevalence of osteoporosis in patients with nephrolithiasis and vice versa: a cumulative analysis

Purpose

Nephrolithiasis is thought to be a risk factor for osteoporosis, but data assessing if osteoporosis predisposes to the risk of nephrolithiasis are lacking. The present study aims to investigate whether patients with nephrolithiasis have a prominently higher prevalence of osteoporosis than the controls and vice versa via a cumulative analysis.

Methods

Four databases were used to detect the eligible studies. We calculated the relative risk (RR) with a 95% confidence interval (CI) to assess the combined effect. The methodologies for conducting this study followed the PRISMA guidelines and were registered in the PROSPERO (ID: CRD42023395875).

Results

Nine case-control or cohort studies with a total of 454,464 participants were finally included. Combined results indicated that there was a significantly higher prevalence of osteoporosis in patients with nephrolithiasis as compared to the general population without nephrolithiasis (overall RR from six studies= 1.204, 95%CI: 1.133 to 1.28, P< 0.001; heterogeneity: I2 = 34.8%, P= 0.162). Conversely, osteoporosis was significantly correlated to an increased risk of nephrolithiasis as compared to the controls without osteoporosis (overall RR from four studies= 1.505, 95%CI: 1.309 to 1.731, P< 0.001; I2 = 89.8%, P< 0.001). Sensitivity analysis on the two categories validated the above findings. No significant publication bias was identified in this study.

Conclusions

The present study highlighted a significantly high prevalence of osteoporosis in patients with nephrolithiasis and vice versa. This reciprocal association reminded the clinicians to conduct a regular follow-up assessment when managing patients with nephrolithiasis or osteoporosis, especially for the elderly.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#searchadvanced, identifier CRD42023395875.

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

OBJECTIVES

We evaluated the baseline characteristics, and risk factors of renal stone recurrence among Saudi Arabian patients after successful primary stone treatment.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

Male gender, hypertension, primary hyperparathyroidism, low fluid intake and high daily protein intake increase the risk of renal stone recurrence among Saudi Arabian patients.

The impact of secondhand smoke on the development of kidney stone disease is not inferior to that of smoking: a longitudinal cohort study

BACKGROUND

Tobacco use and secondhand smoke (SHS) are risk factors of kidney stone disease (KSD). The hypothesis is that tobacco produces chemicals that increase oxidative stress and vasopressin, which leads to decreased urine output, and contributes to stone formation. The aim of this study was to examine the effects of smoking and SHS on the development of KSD.

MATERIALS AND METHODS

We analyzed a total of 25,256 volunteers with no history of KSD participated in the Taiwan Biobank. The presence of underlying and follow-up KSD was surveyed by a self-administrated questionnaire. They were classified into three groups on the basis of smoking and SHS exposure, accessed with survey questionnaires; never-smokers with no SHS exposure, never-smokers with SHS exposure and ever-smokers groups.

RESULTS

KSD was noted in 352 (2.0%), 50 (3.3%) and 240 (4.1%) subjects in the never-smokers with no SHS exposure, never-smokers with SHS exposure and ever-smokers groups, respectively, with a mean follow-up of 4 years. The odds ratio (OR) of KSD was higher in the never-smokers with SHS exposure (OR, 1.622; 95% confidence interval [95% CI], 1.225 to 2.255) and ever-smokers groups (OR, 1.282; 95% CI, 1.044 to 1.574) than in the never-smokers with no SHS exposure group after adjustment of confounders. In addition, never-smokers with SHS exposure had similar effects on the development of KSD than ever-smokers (OR, 1.223; 95% CI, 0.852 to 1.756).

CONCLUSION

Our study suggests that both smoking and SHS are a risk factor for developing KSD and that the impact of SHS is not inferior to that of smoking.

TRIAL REGISTRATION

The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Kaohsiung Medical University Hospital (KMUHIRB-E(I)-20,210,058).

Prospective comparison of extracorporeal shock wave lithotripsy and ureteroscopy in distal ureteral stones

The optimal treatment modality of distal ureteral stones is controversial. Therefore, we conducted a prospective study to evaluate the efficacy, safety, and cost of early second shock wave lithotripsy (SWL) sessions versus ureterorenoscopy (URS) in patients with distal ureteral stones. This prospective study was conducted in a tertiary hospital from June 2020 to April 2022. Patients who underwent SWL or URS for distal ureteral stones were enrolled in this study. The stone-free rate (SFR), secondary treatment rate, complications, and costs were recorded. Propensity-score matching (PSM) analysis was also performed. A total of 1023 patients were included, of whom 68.4% (700) were treated with SWL and 31.6% (323) with URS. Based on PSM, SWL had an equivalent SFR (87.4% vs. 84.9%, P = 0.325) at one month after SWL and secondary treatment rate (10.7% vs.10.8%, P = 0.958) when compared with URS. Complications were rare and comparable between the SWL and URS groups (6.0% vs. 5.9%, P > 0.05), while the incidence of ureteral injuries (i.e., perforations) was higher in the URS group compared with the SWL group (1.3% vs. 0%, P = 0.019). The hospital stay was significantly shorter (1 day vs. 2 days, P < 0.001) and the costs considerably less (2000 RMB vs. 25,030 RMB; P < 0.001) in the SWL group compared with the URS group. This prospective study demonstrated that early second SWL sessions had equivalent efficacy in addition to reduced complication rates and costs compared with URS in patients with distal ureteral stones. Our findings may help guide clinical decision making.

Electromechanically Functionalized Ureteral Stents for Wireless Obstruction Monitoring

While millions of ureteral stents are placed in patients with urinary tract issues around the world every year, hydronephrosis still poses great danger to these patients as a common complication. In the present work, an intelligent double-J ureteral stent equipped with a micro pressure sensor and antenna circuitry is investigated and prototyped toward enabling continuous wireless monitoring of kidney pressure to detect a ureteral obstruction and the resultant hydronephrosis via the indwelling stent. This electromechanically functionalized "intelligent" ureteral stent acts as a radiofrequency resonator with a pressure-sensitive resonant frequency that can be interrogated using an external antenna to track the local pressure. The prototype passes mechanical bending tests of up to 15 cm radius of curvature and shows wireless sensing with a sensitivity of 3.1 kHz/mmHg in artificial urine, which represents 25× enhancement over the preceding design, using an in vitro model with test tissue layers and a pressure range that functions within the conditions found in hydronephrotic conditions. These promising results are expected to propel intelligent ureteral stent technology into further clinical research.

Efficacy of acupuncture for pain relief in patients receiving extracorporeal shock wave lithotripsy: a meta-analysis of randomized controlled studies

Background

This meta-analysis aimed at investigating the efficacy of acupuncture for pain relief in patients receiving extracorporeal shock wave lithotripsy (ESWL).

Methods

Randomized controlled trials comparing the efficacy of acupuncture with conventional treatments were retrieved from major electronic databases (e.g., MEDLINE, EMBASE, and Cochrane Library) until August 28, 2022. The primary outcome was the response rate (i.e., rate of pain relief), while secondary outcomes included stone-free rate, satisfaction rate, duration of ESWL, peri-/post-procedural pain score, and risk of adverse events.

Results

Thirteen eligible studies involving 1,220 participants published between 1993 and 2022 were analyzed. Pooled results indicated that acupuncture had a better response rate compared to conventional treatments (RR = 1.17, 95% CI: 1.06-1.3, p = 0.003, seven trials, n = 832). Despite no difference in ESWL duration (MD = 0.02 min, 95% CI: -1.53 to 1.57, p = 0.98, three trials, n = 141), stone-free rate (RR = 1.11, 95% CI: 1-1.25, p = 0.06, six trials, n = 498), and satisfaction rate (RR = 1.51, 95% CI: 0.92-2.47, p = 0.1, three trials, n = 334) between the two groups, the acupuncture group had a lower risk of adverse events (RR = 0.51, 95% CI: 0.33-0.79, p = 0.003, five trials, n = 327), peri- (MD = -1.91 points, 94% CI: -3.53 to -0.28, p = 0.02, four trials, n = 258 patient) and post-procedural (MD = -1.07, 95% CI: -1.77 to -0.36, p = 0.003, four trials, n = 335) pain score.

Conclusion

The results of this meta-analysis showed that the use of acupuncture in patients receiving ESWL was associated with a higher pain relief rate and a lower risk of adverse events, suggesting feasibility of its use in this clinical setting.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022356327.

Translation and validation of the Chinese version of Wisconsin Stone Quality of Life questionnaire in patients with kidney stones

BACKGROUND

Wisconsin Stone Quality of Life (WISQOL) has been designed specifically for patients with kidney stones. The present study aimed to develop the Chinese version of WISQOL and reach its validation.

METHODS

The WISQOL was translated into Chinese following a standard procedure. Kidney stone patients admitted for surgical treatment were enrolled and fulfilled both WISQOL and SF-36 on the admission day and at one month postoperatively. The internal consistency, inter-domain correlation and convergent validity were analyzed.

RESULTS

One hundred twenty-four 124 males and 76 females were enrolled. The total WISQOL Score and SF-36 had significant correlation both preoperatively (r=0.772, P<0.01) and postoperatively (r=0.639, P<0.01). The internal consistency of the Chinese version WISQOL's different domains ranged from 0.766 to 0.959. The value of Spearman rank correlation to assess the convergent validity of different domains ranged from 0.444 to 0.687. The postoperative WISQOL raised about 20% showing a better quality of life.

CONCLUSIONS

The Chinese version of WISQOL questionnaire was a reliable tool to evaluate the health quality of life in Chinese-speaker patients with kidney stones. To evaluate its test-retest reliability, reliability and validity in a longer term, further studies are required.

The effectiveness of citrates and pyridoxine in the treatment of kidney stones

The prevalence of nephrolithiasis is increasing across all demographic groups. Apart from the morbidity associated with an acute occurrence, preventative treatment is essential for stone disease, which can become a long-term problem. Simple interventions like fluid intake optimization and dietary modification are effective for most stone types. However, patients with specific metabolic abnormalities may require pharmaceutical therapy if lifestyle changes are insufficient to reduce the risk of stone recurrence. The treatment of citrates and/or pyridoxines may help eliminate or prevent recurrences of kidney stones, especially when they are composed of uric acid, calcium oxalate, calcium phosphate, or the latter two together. In cases of struvite stones, which often necessitate a surgical approach, acetohydroxamic acid emerges as a valuable second-line treatment option. Thiol-binding agents may be needed for cystinuria, as well as lifestyle modifications. Successful treatment reduces stone recurrence and the need to remove stones surgically.

Improving Outcomes of Same-sitting Bilateral Flexible Ureteroscopy for Renal Stones in Real-world Practice-Lessons Learnt from Global Multicenter Experience of 1250 Patients

Background

Bilateral kidney stones are commonly treated in staged procedures.

Objective

To evaluate outcomes after same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS) for renal stones.

Design setting and participants

Data from adults who underwent bilateral RIRS in 21 centers were retrospectively reviewed (from January 2015 to June 2022). The inclusion criteria were unilateral/bilateral symptomatic bilateral stone(s) of any size/location in both kidneys and bilateral stones on follow-up with symptom/stone progression. Stone-free rate (SFR) was defined as absence of any fragment >3 mm at 3 mo.

Outcome measurements and statistical analysis

Continuous variables are presented as medians and 25-75th percentiles. A multivariable logistic regression analysis was performed to evaluate independent predictors of sepsis and bilateral SFR.

Results and limitations

A total of 1250 patients were included. The median age was 48.0 (36-61) yr. Of the patients, 58.2% were prestented. The median stone diameter was 10 mm on both sides. Multiple stones were present in 45.3% and 47.9% of the left and right kidneys, respectively. Surgery was stopped in 6.8% of cases. The median surgical time was 75.0 (55-90) min. Complications were transient fever (10.7%), fever/infection needing prolonged stay (5.5%), sepsis (2%), and blood transfusion (1.3%). Bilateral and unilateral SFRs were 73.0% and 17.4%, respectively. Female (odds ratio [OR] 2.97, 95% confidence interval [CI] 1.18-7.49, p = 0.02), no antibiotic prophylaxis (OR 5.99, 95% CI 2.28-15.73, p < 0.001), kidney anomalies (OR 5.91, 95% CI 1.96-17.94, p < 0.001), surgical time ≥100 min (OR 2.86, 95% CI 1.12-7.31, p = 0.03) were factors associated with sepsis. Female (OR 1.88, 95% CI 1.35-2.62, p < 0.001), bilateral prestenting (OR 2.16, 95% CI 1.16-7.66, p = 0.04), and the use of high-power holmium:YAG laser (OR 1.63, 95% CI 1.14-2.34, p < 0.01) and thulium fiber laser (OR 2.50, 95% CI 1.32-4.74, p < 0.01) were predictors of bilateral SFR. Limitations were retrospective study and no cost analysis.

Conclusions

SSB-RIRS is an effective treatment with an acceptable complication rate in selected patients with kidney stones.

Patient summary

In this large multicenter study, we looked at outcomes after same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS) for renal stones in a large cohort. We found that SSB-RIRS was associated with acceptable morbidity and good stone clearance after a single session.

Diagnostic accuracy of Doppler twinkling artifact for identifying urolithiasis: a systematic review and meta-analysis

OBJECTIVE

The goal of this study was to perform a comprehensive meta-analysis to assess the overall diagnostic value of Doppler twinkling for the diagnosis of urolithiasis.

METHODS

We systematically searched the PubMed, EMBASE, and Cochrane Library databases from inception through May 31, 2021. Studies including patients with urolithiasis who underwent color flow Doppler sampling to highlight the twinkling artifact and computed tomography were included. Diagnostic test meta-analysis was performed with a bivariate model. We used summary receiver operating characteristic curves to summarize the overall diagnostic performance. The weighted sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were calculated.

RESULTS

Sixteen studies involving 4572 patients were included in the systematic review and meta-analysis. The weighted sensitivity was 0.86 (95% confidence interval [CI] 0.72-0.94), specificity 0.92 (95% CI 0.75-0.98), positive likelihood ratio 11.3, negative likelihood ratio 0.2, and diagnostic odds ratio 75.5.

CONCLUSION

The Doppler twinkling artifact has good diagnostic value for the diagnosis of urolithiasis and should be used as a complementary tool in the diagnosis of urolithiasis.

The predictive factors that total laser energy consumed during retrograde intrarenal surgery (RIRS): stone area and density

Holmium: YAG (Ho: YAG) laser lithotripsy with flexible ureterorenoscopy can be used with high stone-free and low complication rates for renal stones. This study aimed to determine the factors affecting the total laser energy in cases with provided stone-free status after a single session of retrograde intrarenal surgery (RIRS). Data of 222 patients who underwent RIRS between October 2017 and March 2020 were evaluated retrospectively. After exclusion criteria, the study was carried out with 184 stone-free cases. All cases were performed without using a ureteral access sheath (UAS), and dusting was preferred as the lithotripsy method. The effects of age, gender, body mass index (BMI), previous RIRS history, previous shock wave lithotripsy (SWL) history, stone localization, number of stones, stone surface area, and stone density on total laser energy were analyzed. There was no significant correlation between total laser energy with gender, BMI, previous RIRS history, previous SWL history, stone localization, and the number of stones (p:0.347, p:0.482, p:0.119, p:0.167, p:0.907, p:0.933 respectively). There was a significant correlation between age and total laser energy (p = 0.032), but it was not observed when the effect of the stone surface area was removed (p = 0.354). There were significant correlations between total laser energy and stone surface area, stone density, and total laser time (p<0.001, p<0.001, and p <0.001, respectively). Stone area and stone density affect the total energy consumed during laser lithotripsy. Urologists should consider the stone area, stone density, and the power of the laser device to determine which surgical technic to prefer.

Could METS-VF provide a clue as to the formation of kidney stones?

Objective

The lifetime occurrence rate of kidney stones is 14%, making it one of the most prevalent urological conditions. Other contributing elements, such as obesity, diabetes, diet, and heredity, are also taken into account. Our research sought to explore the potential link between high visceral fat scores (METS-VF) and the occurrence of kidney stones, as a means of understanding how to prevent them.

Methods

This research utilized data from the National Health and Nutrition Examination Survey (NHANES), mirroring the demographics of the United States. We carried out an in-depth analysis of the connection between METS-VF and kidney stones, based on data from 29,246 participants in the National Health and Nutrition Examination Survey spanning 2007 to 2018, involving logistic regression, segmentation, and dose-response curve analysis.

Results

Our study of 29,246 potential participants found that METS-VF was positively associated with the prevalence and progression of kidney stones. After subgroup analysis by gender, race, blood pressure, and blood glucose, our results showed that the ORs for METS-VF and kidney stones were (1.49, 1.44) in males and females, respectively; while in Mexicans, whites, blacks, and In other populations, the OR values were (1.33, 1.43, 1.54, 1.86); in hypertensive and normal populations, the OR values were (1.23, 1.48); in diabetic patients and normoglycemic patients were (1.36,1.43). This proves that it works for all groups of people.

Summary

Our studies demonstrate a strong connection between METS-FV and the emergence of kidney stones. It would be beneficial to investigate METS-VF as a marker for kidney stone development and progression in light of these findings.

Metabolic changes in kidney stone disease

Kidney stone disease (KSD) is one of the earliest medical diseases known, but the mechanism of its formation and metabolic changes remain unclear. The formation of kidney stones is a extensive and complicated process, which is regulated by metabolic changes in various substances. In this manuscript, we summarized the progress of research on metabolic changes in kidney stone disease and discuss the valuable role of some new potential targets. We reviewed the influence of metabolism of some common substances on stone formation, such as the regulation of oxalate, the release of reactive oxygen species (ROS), macrophage polarization, the levels of hormones, and the alternation of other substances. New insights into changes in substance metabolism changes in kidney stone disease, as well as emerging research techniques, will provide new directions in the treatment of stones. Reviewing the great progress that has been made in this field will help to improve the understanding by urologists, nephrologists, and health care providers of the metabolic changes in kidney stone disease, and contribute to explore new metabolic targets for clinical therapy.

Impact of body mass index on size and composition of urinary stones: a systematic review and meta-analysis

BACKGROUND

Several studies have explored the impact of BMI on size and composition of urinary stones. Because there were controversies, a meta-analysis was necessary to be carried out to provide some evidence of the relationship of BMI and urolithiasis.

MATERIALS AND METHODS

PubMed, Medline, Embase, Web of Science databases, and the Cochrane Library were searched up to August 12th 2022 for eligible studies. The urolithiasis patients were summarized into two groups: BMI < 25 and ≥ 25 kg/m2. Summary weighted mean difference (WMD), relative risk (RR) and 95% confidence intervals (CI) were calculated through random effects models in RevMan 5.4 software.

RESULTS

A total of fifteen studies involving 13,233 patients were enrolled in this meta-analysis. There was no significant correlation of BMI and size of urinary stone (WMD -0.13mm, 95% CI [-0.98, 0.73], p = 0.77). Overweight and obesity increased the risk of uric acid stones in both genders and in different regions (RR=0.87, [95% CI] = 0.83, 0.91, p<0.00001). There was a higher risk of calcium oxalate stones formation in overweight and obesity group in total patients (RR=0.95, [95% CI] = 0.91, 0.98, p = 0.006). The relationship of BMI and calcium phosphate was not observed in this meta-analysis (RR=1.12, [95% CI] = 0.98, 1.26, p = 0.09). Sensitivity analysis was performed and indicated similar results.

CONCLUSIONS

The current evidence suggests a positive association between BMI and uric acid and calcium oxalate stones. It would be of great guiding significance to consider losing weight when treating and preventing urinary stones.

A Newly Developed Hematuria Grading System May Predict the Status of Stone-Free and Acute Pyelonephritis of Minimally Invasive Renal Stone Surgery

OBJECTIVES

The aim of this study was to evaluate the level of hematuria and the presence of clots during retrograde intrarenal surgery (RIRS) and miniaturized percutaneous nephrolithotomy (mPCNL) to predict surgical outcomes.

MATERIALS AND METHODS

The data of patients who underwent RIRS and mPCNL were analyzed separately. A hematuria grading (HG) system was classified into five grades based on the presence of blood clots and any visible stones according to the irrigation settings. Inter-observer reliability of the grading system was assessed using intra-class correlation and Spearman's rho.

RESULTS

The HG system showed high agreement among examiners, with high intra-class reliability and a strong correlation between RIRS and mPCNL groups. The stone density of the Houns-field unit was the most important factor in determining the hematuria across the development and validation groups of RIRS and mPCNL patients. Multivariate logistic regression analysis showed that the HG system was a significant predictor for remnant stones in the PCNL group and the probability of acute pyelonephritis or sepsis in the RIRS group. The high hematuria group showed lower basketing difficulty with the basket with a blue marker instrument than with others.

CONCLUSIONS

The new HG system shows excellent inter-observer reliability and a correlation with a gradual increase in stone density and surgical difficulty.

Finding the optimal candidate for shock wave lithotripsy: external validation and comparison of five prediction models

We aimed to externally validate five previously published predictive models (Ng score, Triple D score, S3HoCKwave score, Kim nomogram, Niwa nomogram) for shock wave lithotripsy (SWL) single-session outcomes in patients with a solitary stone in the upper ureter. The validation cohort included patients treated with SWL from September 2011 to December 2019 at our institution. Patient-related variables were retrospectively collected from the hospital records. Stone-related data including all measurements were retrieved from computed tomography prior to SWL. We estimated discrimination using area under the curve (AUC), calibration, and clinical net benefit based on decision curve analysis (DCA). A total of 384 patients with proximal ureter stones treated with SWL were included in the analysis. Median age was 55.5 years, and 282 (73%) of the sample were men. Median stone length was 8.0 mm. All models significantly predicted the SWL outcomes after one session. S3HoCKwave score, Niwa, and Kim nomograms had the highest accuracy in predicting outcomes, with AUC 0.716, 0.714 and 0.701, respectively. These three models outperformed both the Ng (AUC: 0.670) and Triple D (AUC: 0.667) scoring systems, approaching statistical significance (P = 0.05). Of all the models, the Niwa nomogram showed the strongest calibration and highest net benefit in DCA. To conclude, the models showed small differences in predictive power. The Niwa nomogram, however, demonstrated acceptable discrimination, the most accurate calibration, and the highest net benefit whilst having relatively simple design. Therefore, it could be useful for counselling patients with a solitary stone in the upper ureter.

Factors Associated With Urolithiasis: A Hospital-Based Case-Control Study

BACKGROUND

Urolithiasis is a common preventable ailment. Previous studies showed that there are a lot of factors, such as dietary, health and environmental factors, which are likely to develop this condition. Only a few research have been conducted on urolithiasis in the UAE. Therefore, our study aimed to identify the factors associated with urolithiasis in the country, identify the symptoms of urolithiasis among the cases and identify the most common diagnostic methods.

METHODOLOGY

It was a case-control study design. The study population was adults above 18 years attending a tertiary care centre. Those who have confirmed diagnosis of urolithiasis and gave informed consent were considered cases and those who have not confirmed diagnosis of urolithiasis as controls. Patients with renal, bladder or urinary tract impairment or anomaly were excluded from the study. Ethical approval was obtained for the study.

RESULTS

Crude odds ratio (OR) showed that age, gender, past treatment for urinary stones, and lifestyle factors such as diet and smoking are risk factors while exercising is a protective factor. Age-adjusted OR found that past treatment for the urinary disease (OR=10.4), consumption of oily food (OR=11.5), consumption of fast food (OR=11.0) and consumption of energy drinks (OR=5.9) were the significant risk factors for urolithiasis.

CONCLUSION

We found that past urinary disease treatment and diet are vital in developing urinary stones. Higher consumption of salty, oily, sugary and protein foods increases the odds of urinary diseases. Public awareness programs are essential to educating people about urolithiasis risk factors and preventive measures.

Pancreatic exocrine insufficiency is a risk factor for kidney stones in patients with chronic pancreatitis

INTRODUCTION

Most patients with chronic pancreatitis (CP) develop pancreatic exocrine insufficiency (PEI) over the course of the disease. PEI may lead to hyperoxaluria and development of urinary oxalate stones. It has been postulated that the patients with CP may be at increased risk of kidney stone formation, but the data is scarce. We aimed to estimate incidence and risk factors for nephrolithiasis in a Swedish cohort of patients with CP.

PATIENTS AND METHODS

We performed retrospective analysis of an electronical medical database of patients diagnosed with definite CP during 2003-2020. We excluded patients <18 years of age, those with missing relevant data in medical charts, patients with probable CP (according to the M-ANNHEIM classification system) and those in whom kidney stones were diagnosed before CP diagnosis.

RESULTS

Some 632 patients with definite CP were followed over a median of 5.3 (IQR 2.4-6.9) years. There were 41 (6.5%) patients diagnosed with kidney stones, of whom 33 (80.5%) were symptomatic. Comparing to patients without kidney stones, patients with nephrolithiasis were older, with median age of 65 (IQR 51-72) years, and a male predominance (80% vs 63%). Cumulative incidence of kidney stones was 2.1%, 5.7%, 12.4% and 16.1% at 5, 10, 15, and 20 years after CP diagnosis, respectively. Multivariable cause-specific Cox regression analysis revealed PEI as independent risk factor for nephrolithiasis (adjusted HR 4.95, 95%CI 1.65-14.84; p = 0.004). Another risk factors were increase in BMI (aHR 1.16 95% CI 1.04-1.30; p = 0.001 per unit increment), and a male sex (4.51, 95% CI 1.01-20.3, p = 0.049).

CONCLUSION

PEI and increase in BMI are risk factors for kidney stone development in patients with CP. Male CP patents are particularly at increased risk of nephrolithiasis. This should be taken into consideration in general clinical approach to raise awareness among patients and medical workers.

The influence of climatic factors in the seasonal fluctuation of urolithiasis and the trend of stone disease management in the southern Taiwan

This study aims to analyze the effects of climate parameters on the number of urolithiasis treatments in our hospital and understand the effects of climate parameters on the prevalence of urolithiasis in southern Taiwan. We also look at trends associated with urolithiasis and treatments. Retrospectively reviewed the records of extracorporeal shockwave lithotripsy (ESWL), ureteroscopy (URS), retrograde intrarenal surgery (RIRS), and percutaneous nephrolithotripsy (PCNL) performed in our hospital from January 2012 to December 2018. Climate data for were collected from Central Weather Bureau. The monthly meteorological data included average temperatures, humidity, rainfall, sunshine hours, atmospheric pressure, and wind speed. Monthly numbers of patients undergoing stone management was positively correlated to average temperature (r = 0.657), relative humidity (r = 0.234), monthly rainfall (r = 0.261) and monthly sunshine hours (r = 0.348), while it was negatively correlated to atmospheric pressure (r = - 0.522). The multivariate linear regression model demonstrated temperature (ß = 10.682, 95% CI 6.178-14.646, p < 0.001) and Relative humidity (ß = - 95% CI - 5.233- - 1.216, p = 0.002) to be independently related to numbers of stone treatment. The data also revealed a rising prevalence of urolithiasis with an associated increase in the number of interventions, with fewer ESWL (74.0-49.4%). Temperature and relative humidity are associated with monthly numbers of stone treatment. Ambient temperature is the most critical climate factor affecting the prevalence of symptomatic urolithiasis and intention of active stone removal in southern Taiwan.

Associations between dietary patterns and nephrolithiasis risk in a large Chinese cohort: is a balanced or plant-based diet better?

Purpose: Individual food items and nutrients are associated with the development of nephrolithiasis. Few studies have investigated the association between dietary patterns, particularly plant-based diets, and this disease. We aim to explore the associations between dietary patterns and incident nephrolithiasis risk. Materials and methods: This prospective cohort study included 26 490 participants. Factor analysis was applied to dietary information to identify three a posteriori dietary patterns, and six a priori plant-based dietary patterns (overall plant-based diet index [PDI], healthful plant-based diet index [hPDI], unhealthful plant-based diet index [uPDI], vegan diet, lacto-ovo-vegetarian diet, and fish-vegetarian diet) were defined. Nephrolithiasis was diagnosed using ultrasonography. Cox proportional hazard regression models were used to assess the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident nephrolithiasis related to dietary patterns. Results: After 101 094 person-years follow-up, we documented 806 incident nephrolithiasis cases. An a posteriori balanced dietary pattern characterized by a higher intake of vegetables, eggs, grains, legumes, legume products, and meat was associated with a lower risk of nephrolithiasis (P for trend = 0.02). Compared to the reference group in the lowest quartile of the balanced pattern, participants in the highest quartile had an adjusted HR (95% CI) of 0.72 (0.53-0.96) for incident nephrolithiasis. Adherence to the uPDI increased the risk of incident nephrolithiasis (P for trend < 0.01; adjusted HR_{4th quartile vs. 1st quartile}, 1.46, 95% CI, 1.14-1.97). No significant association was found between other a posteriori or a priori dietary patterns and incident nephrolithiasis. Conclusions: Adherence to a balanced dietary pattern, but not a plant-based diet, was associated with a lower nephrolithiasis risk. Moreover, higher uPDI consumption increased incident nephrolithiasis risk.

Bioinformatics analysis reveals the potential role of matrix metalloproteinases in immunity and urolithiasis

Background

The pathogenesis of urolithiasis remains unclear, making the development of medications for treatment and prevention stagnant. Randall’s plaques (RPs) begin as interstitial calcium phosphate crystal deposits, grow outward and breach the renal papillary surface, acting as attachment for CaOx stones. Since matrix metalloproteinases (MMPs) can degrade all components of extracellular matrix (ECM), they might participate in the breach of RPs. Besides, MMPs can modulate the immune response and inflammation, which were confirmed to be involved in urolithiasis. We aimed to investigate the role of MMPs in the development of RPs and stone formation.

Methods

The public dataset GSE73680 was mined to identify differentially expressed MMPs (DEMMPs) between normal tissues and RPs. WGCNA and three machine learning algorithms were performed to screen the hub DEMMPs. In vitro experiments were conducted for validation. Afterwards, RPs samples were classified into clusters based on the hub DEMMPs expression. Differentially expressed genes (DEGs) between clusters were identified and functional enrichment analysis and GSEA were applied to explore the biological role of DEGs. Moreover, the immune infiltration levels between clusters were evaluated by CIBERSORT and ssGSEA.

Results

Five DEMMPs, including MMP1, MMP3, MMP9, MMP10, and MMP12, were identified between normal tissues and RPs, and all of them were elevated in RPs. Based on WGCNA and three machine learning algorithms, all of five DEMMPs were regarded as hub DEMMPs. In vitro validation found the expression of hub DEMMPs also increased in renal tubular epithelial cells under lithogenic environment. RPs samples were divided into two clusters and cluster A exhibited higher expression of hub DEMMPs compared to cluster B. Functional enrichment analysis and GSEA found DEGs were enriched in immune-related functions and pathways. Moreover, increased infiltration of M1 macrophages and enhanced levels of inflammation were observed in cluster A by immune infiltration analysis.

Conclusion

We assumed that MMPs might participate in RPs and stone formation through ECM degradation and macrophages-mediated immune response and inflammation. Our findings offer a novel perspective on the role of MMPs in immunity and urolithiasis for the first time, and provide potential biomarkers to develop targets for treatment and prevention.

Anti-urolithiatic effect of Cucumis melo L. var inodorous in male rats with kidney stones

Melon seed extracts have high antioxidant activities and are effective against a variety of diseases, including kidney stones. In kidney stone model rats, the anti-urolithiatic effects of the hydro-ethanolic extract of melon seed and potassium citrate were studied and compared. After urolithiasis induction by ethylene glycol, the extract and potassium citrate were treated orally for 38 days concurrent with ethylene glycol. Then, urine and kidney sampling were done, and the urinary parameter levels were measured. The melon and potassium citrate treatments reduced the kidney index, the levels of urinary calcium and oxalate, calcium oxalate deposit numbers, the score of crystal deposits, histo-pathological damages, and the score of inflammation in the kidney sections, while elevating the urinary pH, magnesium, and citrate levels, and also the expression of the UMOD, spp1, and reg1 genes in the kidney of treated animals. The effect of potassium citrate is the same as the effect of melon in treated animals. So, their effects could be by normalizing urinary parameters, reducing crystal deposits, excreting small deposits from the kidney, reducing the chance of them being retained in the urinary tract, and elevating the expression of the UMOD, spp1, and reg1 genes, which are involved in kidney stone formation.

The role of microbiome: a novel insight into urolithiasis

Urolithiasis, referred to as the formation of stones in the urinary tract, is a common disease with growing prevalence and high recurrence rate worldwide. Although researchers have endeavoured to explore the mechanism of urinary stone formation for novel effective therapeutic and preventative measures, the exact aetiology and pathogenesis remain unclear. Propelled by sequencing technologies and culturomics, great advances have been made in understanding the pivotal contribution of the human microbiome to urolithiasis. Indeed, there are diverse and abundant microbes interacting with the host in the urinary tract, overturning the dogma that urinary system, and urine are sterile. The urinary microbiome of stone formers was clearly distinct from healthy individuals. Besides, dysbiosis of the intestinal microbiome appears to be involved in stone formation through the gut-kidney axis. Thus, the human microbiome has potential significant implications for the aetiology of urolithiasis, providing a novel insight into diagnostic, therapeutic, and prognostic strategies. Herein, we review and summarize the landmark microbiome studies in urolithiasis and identify therapeutic implications, challenges, and future perspectives in this rapidly evolving field. To conclude, a new front has opened with the evidence for a microbial role in stone formation, offering potential applications in the prevention, and treatment of urolithiasis.

Metabolic evaluation of first-time uncomplicated renal stone formers: A prospective study

Background

Nephrolithiasis is a global health problem. The recurrence rate after the first stone clearance is approximately 50% at 5 years. Metabolic abnormalities are an important factor responsible for stone recurrence. Our prevalidated study aimed to evaluate metabolic abnormalities associated with first-time uncomplicated renal stone formers (FTURSF).

Materials and methods

In this prospective, exploratory, time-bound, descriptive study, 30 first-time renal stone formers were evaluated for metabolic abnormalities. High-risk stone formers were excluded from the study. Data were collected in a predefined proforma, transferred to an Excel sheet, and analyzed using the Statistical Package for Social Sciences 20 and Epi Info 7. Fisher exact test, Mann-Whitney U test, paired t test, and Pearson correlation coefficient were used for statistical analyses.

Results

The mean age of the participants was 35.57 ± 11.07 years, with a male-to-female ratio of 1.72. The most common abnormality was a 24-hour urine volume of <2.5 L in 73.33% of the participants. One or more metabolic abnormalities were detected in 76.67% of the participants. Other common metabolic abnormalities detected were hypocitraturia (60%), hypercalciuria (16.67%), hyperoxaluria (13.33%), and hyperuricosuria (3.33%). Parathyroid adenoma was detected in one participant (3.33%).

Conclusions

Our study documented significant metabolic abnormalities in FTURSF. Therefore, a simplified metabolic evaluation protocol should be adopted while evaluating FTURSF. Detection of an underlying metabolic abnormality would enable the early institution of preventive measures to reduce stone recurrence and related complications.

Learning curve in flexible ureteroscopy for renal stones: A propensity score-matched study

OBJECTIVE

To assess the learning curve and evaluate the impact of surgical experience related to the outcomes of flexible ureteroscopy (fURS) for upper urinary tract stones.

METHOD

We evaluated retrospectively lithiasis fURS performed in our institution between January 2004 and December 2020. Patients were divided into two groups by the number of procedures performed by surgeon. Group 1 (G1) included the first 50 procedures, and group 2 (G2) the next cases. These groups were matched on baseline characteristics by a propensity score. Stones free rate (SFR) and complication rate (CR) were compared. Learning curves were realized using logistic curve with 95% confidence interval.

RESULTS

After criteria exclusion and propensity score matching, 1548 procedures were analyzed (1:1, G1 and G2, n=774 procedures). A total of 29 surgeons were evaluated. The overall SFR was 68.4% without statistical difference between the two groups (G1=67.9% vs. G2=68.8%, P=0.72). The surgeon's experience was not associated with SFR (OR=1.15, 95% CI: 0.90-1.47), except in subgroup stones>2cm (OR=2.89, 95% CI: 1.29-6.46). The overall CR was 12.5%, mainly Clavien-Dindo grade I-II complications (96.2%). Surgical experience was not associated with CR (OR=1.06, 95% CI: 0.77-1.45). The overall logistic curves for probability of stone clearance and complication tended to be a flat slope.

CONCLUSION

Impact of surgical experience on fURS for UUTS was not associated with SFR and CR. However, for stones larger than 2cm, surgeon's experience tended to be associated with SFR, but without impact on overall complications.

LEVEL OF EVIDENCE: 3

[Evaluation of the results and feasibility of vibration, diuresis and inversion therapy in the treatment of upper urinary tract stones]

OBJECTIVES

To evaluate the feasibility, efficiency, and predictive factors of therapeutic success of Vibration, Diuresis and Inversion (VDI) therapy for the removal of upper urinary tract stones.

METHODS

It is a retrospective, single-center study at the CHU - La Conception, Marseille, France including all patients treated with VDI from 2013 to 2018. VDI was indicated for stones <6mm in first-line treatment or for residual fragments <6mm after ureteroscopy, PCNL, microPCNL. The protocol included 4 sessions in outpatient care from 2013 to 2015 then 6 sessions from 2015 to 2018 and a final radiological evaluation.

RESULTS

In total, 109 patients or 489 sessions are reported: median age was 55 years [14-84], median BMI 25kg/m² [15-37], average cumulative size of kidney stones 3mm ±4. VDI was performed after flexible ureteroscopy (62%), SWL (20%), percutaneous treatment (9%) or as a first-line treatment (9%). Compliance was 87 %. The median VAS during the session was 0[0-8]. The incidence of post-session renal colic was 4% (all Clavien I). The postoperative fragment-free and microfragment rates were respectively 39% and 21%, i.e. an overall success of 60% for kidney stones, and 43% and 21%, i.e. an overall success of 64% for lower pole kidney stones.

CONCLUSION

VDI is a simple, non invasive and well tolerated technique for the elimination of small renal lithiasis after SWL, ureteroscopy, PCNL or as a first-line treatment.

Breakage Costs in Flexible Ureteroscopy: Digital vs. Fiberoptic Modalities

OBJECTIVE

To compare the maintenance costs of digital flexible ureteroscopes (DFU) versus fiberoptic flexible ureteroscopes (FFU) to understand the long-term financial impact associated with breakage in a flexible ureteroscopy (f-URS) program.

METHODS

Data for breakage of FFU and DFU at an academic institution from 2019 to 2021 were obtained from our vendor (Karl Storz) and analyzed by month. Correlation test was used to evaluate significant differences in number of procedures, number of breakage events, breakage rates, and repair cost per month. Cumulative analyses were utilized to examine the number of procedures before failure (time to failure - TTF) and repair costs per procedure (RCpP).

RESULTS

We performed a total of 2,154 f-URS, including 1,355 with FFU and 799 with DFU (P<.001). Although we found a higher number of breakage events in FFU (n=124) than DFU (n=73) (P<.001), the overall breakage rate was similar, 9.9% vs. 8.8%, respectively (P=0.86). On cumulative analysis, both modalities reached the same TTF plateau (11 cases) after 18 months. After 400 cases, the RCpP for DFU was 1.25 times higher than for FFU (P=0.04).

CONCLUSION

Overall, we found no difference in overall scope breakage rates between DFU and FFU. Although there was no difference in TTF over time, at the beginning DFU displayed considerable higher durability, leading to lower RCpP. Furthermore, DFU's endurance leveled off to FFU over time, resulting in higher RCpP after 400 cases. This finding may be explained by the presence of renewed scopes after repair.

Tea intake and risk of kidney stones: A mendelian randomization study

OBJECTIVES

Observational studies indicate that tea intake is associated with a decreased risk of kidney stones. Here we performed a mendelian randomization (MR) analysis to evaluate whether this association is causal.

METHODS

Forty-four independent genetic variants strongly associated with tea intake were identified from a large genome-wide association study, including 448 060 individuals of the UK Biobank. We additionally obtained genome-wide association study summary statistics for kidney stones from the FinnGen consortium (5985 cases and 253 943 controls) and UK Biobank (6536 cases and 388 508 controls). Random-effect inverse variance weighted regression was used to evaluate causal estimates. The random-effect inverse variance weighted estimates based on the FinnGen consortium and UK Biobank were meta-analyzed using fixed-effects meta-analysis. Other MR methods, including MR-Egger, weighted median, weighted mode, and MR-Pleiotropy RESidual Sum and Outlier, were also performed to test the robustness of our results.

RESULTS

In a combined sample of 12 521 cases and 642 451 controls, the inverse variance weighted analysis indicated that genetically predicted tea intake was causally associated with a decreased risk of kidney stones (odds ratio = 0.47; 95% CI, 0.34-0.66; P < 0.001). This association was consistent in other MR methods.

CONCLUSIONS

This study suggests that tea intake may be causally associated with a decreased risk of kidney stones.

Preoperative patient optimization for endourological procedures: the current best clinical practice

PURPOSE OF REVIEW

Despite technological advancements in endourological surgery, there is room for improvement in preoperative patient optimization strategies. This review updates recent best clinical practices that can be implemented for optimal surgical outcomes.

RECENT FINDINGS

Outcome and complication predictions using novel scoring systems and techniques have shown to assist clinical decision-making and patient counseling. Innovative preoperative simulation and localization methods for percutaneous nephrolithotomy have been evaluated to minimize puncture-associated adverse events. Novel antibiotic prophylaxis strategies and further recognition of risk factors that attribute to postoperative infections have shown the potential to minimize perioperative morbidity. Accumulating data on the roles of preoperative stenting and selective oral alpha-blockers adds evidence to the current paradigm of preventive measures for ureteral injury.

SUMMARY

Ample tools and technologies exist that can be utilized preoperatively to improve surgical outcomes. The combination of these innovations, along with validation in larger-scale studies, presents the cornerstone of future urolithiasis management.

Cucumis callosus (Rottl.) Cogn. fruit extract ameliorates calcium oxalate urolithiasis in ethylene glycol induced hyperoxaluric Rat model

Cucumis callosus dry fruits are traditionally used as folk remedy to treat conditions like urethral irritations, urine stoppage or dribbling and other urinary ailments of man in north-west India. But no study is reported to validate this ethnic practice of using Cucumis fruit in urolithiasis. To evaluate anti-urolithiatic potential of Cucumis, hyperoxaluria was induced in rats by supplying 0.75% ethylene glycol (EG) + 1% ammonium chloride (AC) in drinking water for 14 days. Anti-urolithiatic activity of Cucumis callosus hydro-ethanolic extract (CCHEE) was assessed by measuring blood and urine biochemical parameters, oxidative stress indices, histopathology and osteopontin (OPN) expression. Administration of EG-AC to rats caused hyperoxaluria, crystalluria, azotaemia, oxidant/antioxidant imbalance (increase in lipid peroxidation (LPO), and decrease in glutathione (GSH) and catalase (CAT)), up-regulation of OPN and calcium oxalate (CaOx) crystal deposition in kidney. Treatment of afflicted rats with Cucumis fruits extract restored renal function to a great extent (CCHEE group), testified by improvement of stated parameters. Findings demonstrate curative efficacy of Cucumis fruit extract in EG induced urolithiasis of rats. The restoration of renal function was possibly by regulating renal stone formation via reducing urinary oxalate excretion, correcting oxidant/antioxidant imbalances, and reduced expression of OPN. Hence, results of this study validate the ethnic practice of using Cucumis fruit and conclude that fruit extracts have beneficial effects on CaOx urolithiasis and renal function.

Past, present and future of genomics for kidney stone disease

PURPOSE OF REVIEW

To summarize the latest findings and developments in genomics for kidney stone disease (KSD) that help to understand hereditary pathomechanisms, identify high risk stone formers, provide early treatment and prevent recurrent kidney stone formation.

RECENT FINDINGS

Several gene loci associated to KSD have presently been discovered in large Genome-wide association studies. Monogenic causes are rare, but are thought to have higher penetrance, while polygenic causes are more frequent with less penetrance. Although there is a great effort identifying genetic causes of KSD, targeted therapies are scarce.

SUMMARY

There have been great advancements in genetic research in identifying genetic variants associated with KSD. Identifying these variants and understanding the underlying pathophysiology will not only provide individual risk assessment but open the way for new treatment targets and preventive care strategies.

Patient compliance to dietary recommendations: tips and tricks to improve compliance rates

Urinary stone disease continues to be a public health problem with growing incidence and recurrences. Recurrence is nearly detected in 50% of the patients within 5 years after the first episode. However, stone recurrence rates can be reduced to a certain extent. The American Urological Association (AUA) and the European Urological Association (EAU) guidelines advice dietary, fluid intake, and medical treatment to prevent or minimize stone recurrence. However, studies have shown that compliance to dietary and fluid intake recommendations is low. Beside this, nutritional evaluation of the patients is sufficient. Using food frequency questionnaires (FFQs), 24 h recall methods (short, individual-oriented, and easily applicable) or mobile apps can be used. In addition, cooperation with registered dietitians (RD) and planning tailored dietary programmes may have positive effect on compliance. Providers who give dietary advices should improve their knowledge about the topic and communication skills to create a patient-provider trust relationship. Simplifying the advices (shorter lists, applicable advices), spending more time, and giving education until being sure for patients' understanding with regular remindings may improve adherence. Moreover, patients increased awareness and knowledge about dietary advices are beneficial. Smart devices for fluid uptake or urine pH monitoring, mobile apps or web-based portals, and telemedicine applications can be used to maintain the compliance on dietary advices. Compliance with dietary modifications and fluid intake recommendations can be well achieved by individualized evaluation/close follow-up and the elimination of the problems limiting the patient compliance.

The Swiss Kidney Stone Cohort: A Longitudinal, Multicentric, Observational Cohort to Study Course and Causes of Kidney Stone Disease in Switzerland

BACKGROUND

Kidney stone disease has a high prevalence worldwide of approximately 10% of the population and is characterized by a high recurrence rate. Kidney stone disease results from a combination of genetic, environmental, and lifestyle risk factors, and the dissection of these factors is complex.

METHODS

The Swiss Kidney Stone Cohort (SKSC) is an investigator-initiated prospective, multicentric longitudinal, observational study in patients with kidney stones followed with regular visits over a period of 3 years after inclusion. Ongoing follow-ups by biannual telephone interviews will provide long-term outcome data. SKSC comprises 782 adult patients (age >18 years) with either recurrent stones or a single stone event with at least one risk factor for recurrence. In addition, a control cohort of 207 individuals without kidney stone history and absence of kidney stones on a low-dose CT scan at enrolment has also been recruited. SKSC includes extensive collections of clinical data, biochemical data in blood and 24-h urine samples, and genetic data. Biosamples are stored at a dedicated biobank. Information on diet and dietary habits was collected through food frequency questionnaires and standardized recall interviews by trained dieticians with the Globodiet software.

CONCLUSION

SKSC provides a unique opportunity and resource to further study cause and course of kidney disease in a large population with data and samples collected of a homogeneous collective of patients throughout the whole Swiss population.

Pediatric Nephrolithiasis

The prevalence of pediatric nephrolithiasis has increased dramatically in the past two decades for reasons that have yet to be fully elucidated. Workup of pediatric kidney stones should include metabolic assessment to identify and address any risk factors predisposing patients to recurrent stone formation, and treatment should aim to facilitate stone clearance while minimizing complications, radiation and anesthetic exposure, and other risks. Treatment methods include observation and supportive therapy, medical expulsive therapy, and surgical intervention, with choice of treatment method determined by clinicians' assessments of stone size, location, anatomic factors, comorbidities, other risk factors, and preferences and goals of patients and their families. Much of the current research into nephrolithiasis is restricted to adult populations, and more data are needed to better understand many aspects of the epidemiology and treatment of pediatric kidney stones.

Comparison of shock wave lithotripsy and ureteroscopy in patients with proximal ureteral stones under the COVID-19 pandemic

PURPOSE

To compare the effectiveness, safety, and cost between ultrasound-guided shock wave lithotripsy (SWL) with an early second session protocol and ureteroscopy (URS) in patients with proximal ureteral stones using the propensity score matching (PSM) method based on a large prospective study.

METHODS

This prospective study was conducted in a tertiary hospital from June 2020 to April 2022. Patients who underwent lithotripsy (SWL or URS) for proximal ureteral stones were enrolled. The stone-free rate (SFR), complications, and cost were recorded. PSM analysis was performed.

RESULTS

A total of 1230 patients were included, of whom 81.1% (998) were treated with SWL and 18.9% (232) were treated with URS. After PSM, the SWL group had an equivalent SFR at one month (88.7 vs. 83.6%, P = 0.114) compared with the URS group. Complications were rare and comparable between the two groups, while the incidence of ureteral injuries was higher in the URS group compared with the SWL group (1.4 vs. 0%, P = 0.011). The hospital stay was significantly shorter (1 day vs. 2 days, P < 0.001), and the cost was considerably less (2000 vs. 25,053, P < 0.001) in the SWL group compared with the URS group.

CONCLUSION

This prospective PSM cohort demonstrated that ultrasound-guided SWL with an early second session protocol had equivalent effectiveness but better safety and lower cost compared with URS in the treatment of patients with proximal ureteral stones, whether the stones were radiopaque or radiolucent. These results will facilitate treatment decisions for proximal ureteral stones.

Epidemiology of Kidney Stones

In the past two decades, major breakthroughs that improve our understanding of the pathophysiology and therapy of kidney stones (KS) have been lacking. The disease continues to be challenging for patients, physicians, and healthcare systems alike. In this context, epidemiological studies are striving to elucidate the worldwide changes in the patterns and the burden of the disease and identify modifiable risk factors that contribute to the development of kidney stones. Our expanding knowledge of the epidemiology of kidney stones is of paramount importance and largely upgrades the modern management of the disease. In this paper, we review the variables affecting prevalence and incidence, including age, gender, race, ethnicity, occupation, climate, geography, systemic diseases, diabetes, vascular disease, chronic kidney disease, and dietary risk factors relevant to kidney stones.

The association between menopause, postmenopausal hormone therapy, and kidney stone disease in Taiwanese women

PURPOSE

The association between menopause, postmenopausal hormone therapy, and kidney stone disease has long been a topic of discussion and is still unclear. Moreover, most previous research has focused on Caucasians. Therefore, we aimed to explore this issue in an Asian population.

METHODS

In this cross-sectional study, we enrolled female participants aged between 30 and 70 years from the Taiwan Biobank. The presence of kidney stone disease (KSD) was defined through a self-reported questionnaire. The participants were divided into two groups according to the presence of menopause; premenopausal and postmenopausal groups. The associations among menopause, postmenopausal hormone therapy, and KSD were examined using binary logistic regression models.

RESULTS

A total of 17,460 women with available information were recruited, including 5976 in the premenopausal group and 11,484 in the postmenopausal group. Compared to the premenopausal group, the postmenopausal group had a significantly higher prevalence of KSD (3% vs. 6%). The odds ratio for KSD was higher in the postmenopausal group than in the premenopausal group (odds ratio = 1.50; 95% confidence interval = 1.17-1.92) after adjusting for confounders. We also examined associations between the type of menopause (natural and surgical) and KSD, and found that both types of menopause were associated with KSD in age-adjusted and multivariable models. Compared with those who had never received postmenopausal hormone therapy, those who had received postmenopausal hormone therapy were not associated with a higher risk of KSD.

CONCLUSIONS

Our study suggests that natural and surgical menopause were associated with KSD. However, we found no association between the postmenopausal hormone therapy and KSD in the postmenopausal women.

Hydration and Nephrolithiasis in Pediatric Populations: Specificities and Current Recommendations

Renal lithiasis is less frequent in children than in adults; in pediatrics, lithiasis may be caused by genetic abnormalities, infections, and complex uropathies, but the association of urological and metabolic abnormalities is not uncommon. The aim of this study is to provide a synthesis of nephrolithiasis in children and to emphasize the role of hydration in its treatment. As an etiology is reported in 50% of cases, with a genetic origin in 10 to 20%, it is proposed to systematically perform a complete metabolic assessment after the first stone in a child. Recent data in the field reported increased incidence of pediatric urolithiasis notably for calcium oxalate stones. These changes in the epidemiology of stone components may be attributable to metabolic and environmental factors, where hydration seems to play a crucial role. In case of pediatric urolithiasis, whatever its cause, it is of utmost importance to increase water intake around 2 to 3 L/m² per day on average. The objective is to obtain a urine density less than 1010 on a dipstick or below 300 mOsm/L, especially with the first morning urine. Some genetic diseases may even require a more active 24 h over-hydration, e.g., primary hyperoxaluria and cystinuria; in such cases naso-gastric tubes or G-tubes may be proposed. Tap water is adapted for children with urolithiasis, with limited ecological impact and low economical cost. For children with low calcium intake, the use of calcium-rich mineral waters may be discussed in some peculiar cases, even in case of urolithiasis. In contrast, sugar-sweetened beverages are not recommended. In conclusion, even if parents and patients sometimes have the feeling that physicians do not propose "fancy" therapeutic drugs, hydration and nutrition remain cornerstones of the management of pediatric urolithiasis.

Identification of the core genes in Randall's plaque of kidney stone and immune infiltration with WGCNA network

Background: Randall's plaque is regarded as the precursor lesion of lithiasis. However, traditional bioinformatic analysis is limited and ignores the relationship with immune response. To investigate the underlying calculi formation mechanism, we introduced innovative algorithms to expand our understanding of kidney stone disease. Methods: We downloaded the GSE73680 series matrix from the Gene Expression Omnibus (GEO) related to CaOx formation and excluded one patient, GSE116860. In the RStudio (R version 4.1.1) platform, the differentially expressed genes (DEGs) were identified with the limma package for GO/KEGG/GSEA analysis in the clusterProfiler package. Furthermore, high-correlated gene co-expression modules were confirmed by the WGCNA package to establish a protein-protein interaction (PPI) network. Finally, the CaOx samples were processed by the CIBERSORT algorithm to anchor the key immune cells group and verified in the validation series matrix GSE117518. Results: The study identified 840 upregulated and 1065 downregulated genes. The GO/KEGG results revealed fiber-related or adhesion-related terms and several pathways in addition to various diseases identified from the DO analysis. Moreover, WGCNA selected highly correlated modules to construct a PPI network. Finally, 16 types of immune cells are thought to participate in urolithiasis pathology and are related to hub genes in the PPI network that are proven significant in the validation series matrix GSE117518. Conclusion: Randall's plaque may relate to genes DCN, LUM, and P4HA2 and M2 macrophages and resting mast immune cells. These findings could serve as potential biomarkers and provide new research directions.

The relationship between ethylene oxide levels in hemoglobin and the prevalence of kidney stones in US adults: an exposure-response analysis from NHANES 2013-2016

Exposure to ethylene oxide may cause a number of diseases. The purpose of this study was to investigate whether there is an association between hemoglobin ethylene oxide (HbEO) and the risk of developing kidney stones in US adults. We analyzed 3348 patients from the National Health and Nutrition Survey (NHANES) 2013-2016 and conducted a cross-sectional study. Dose-response analysis curves of restricted cubic spline function, multiple logistic regression, and subgroup analysis were used to investigate the association between HbEO and the risk of kidney stones. Logistic regression models were used to analyze the correlation between HbEO and kidney stones. Among the 3348 participants, 3016 people self-reported having a kidney stone. After adjusting for age, sex, race, marital status, education level, diabetes, vigorous recreational activity, moderate recreational activity, body mass index, blood urea nitrogen, creatinine, eGFR, and uric acid, we found a positive association between HbEO and the risk of kidney stones. We divided patients into four groups based on quartiles of HbEO levels and performed multifactorial logistic regression after adjusting for confounders, which showed that the incidence of kidney stones increased with increasing HbEO concentrations compared with Q1 (Q2, OR = 0.922, 95% CI, 0. 657-1.295, P = 0.639; Q3, OR = 1.004, 95% CI, 0.713-1.414, P = 0.983; Q4, OR = 1.535, 95% CI, 1.114-2.114, P = 0.009). High levels of HbEO were positively correlated with the risk of kidney stone development and could be used as an indicator of kidney stone prevention.

Comparison of flexible ureteroscopy in the treatment of 1-2 cm single nephrolithiasis and multiple nephrolithiasis

Objective

To compare the efficacy of flexible ureteroscopy for single urinary stones with that of multiple urinary stones.

Methods

A retrospective study was conducted on patients who underwent flexible ureteroscopy in Qilu Hospital of Shandong University from January 2016 to March 2021. Propensity score matching was used to match patients with no statistical difference in preoperative clinical data, and they were divided into solitary calculi and multiple calculi two groups. The postoperative hospital days, operation time, complications and stone free rate were compared between the two groups. And multiple stones were divided into high group (S-ReSc > 4) and non-high group (S-ReSc ≤ 4) for analysis.

Results

313 patients were counted. After propensity score matching, 198 patients were finally included in the study. There were 99 cases in the solitary stone group and the multiple stone group. There were no significant differences in postoperative hospital days, complications and stone free rate between the two groups. The operation time of patients with solitary stone group was significantly shorter than that of patients with multiple stones (65.00 min, 45.00 min VS 90.00 min, 50.00 min, P < 0.001). The SFR of high group in the multiple stones group was significantly lower than that in the non-high group (7, 58.3% VS 78, 89.7%, P = 0.013).

Conclusion

Despite the longer operation time, flexible ureteroscopy has similar outcomes in the treatment of multiple (S-Rec ≤ 4) compared to solitary calculi. Although, this doesn't apply when S-ReSc > 4.

Short-term effects of ambient air pollution on emergency department visits for urolithiasis: A time-series study in Wuhan, China

Background

Previous studies have explored the correlation between short-term exposure to air pollution and urinary system diseases, but lack of evidence on the correlation between air pollution and urolithiasis.

Methods

Daily data of emergency department visits (EDVs), concentrations of six air pollutants (SO₂, NO₂, PM_2.5, PM₁₀, CO, and O₃) and meteorological variables were collected in Wuhan, China, from 2016 to 2018. And a time-series study was conducted to investigate short-term effects of air pollutants on urolithiasis EDVs. In addition, stratified analyses by season, age and gender were also conducted.

Results

A total of 7,483 urolithiasis EDVs were included during the study period. A 10-μg/m³ increase of SO₂, NO₂, PM_2.5, CO, PM₁₀, and O₃ corresponded to 15.02% (95% confidence interval [CI]: 1.69%, 30.11%), 1.96% (95% CI: 0.19%, 3.76%), 1.09% (95% CI:-0.24%, 2.43%), 0.14% (95% CI: 0.02%, 0.26%), 0.72% (95% CI: 0.02%, 1.43%), and 1.17% (95% CI: 0.40%, 1.94%) increases in daily urolithiasis EDVs. Significant positive correlations were observed between SO₂, NO₂, CO, and O₃ and urolithiasis EDVs. The correlations were mainly among females (especially PM_2.5 and CO) and younger people (especially SO₂, NO₂, and PM₁₀) but the effect of CO was more obvious in elders. Furthermore, the effects of SO₂ and CO were stronger in warm seasons, while the effects of NO₂ were stronger in cool seasons.

Conclusion

Our time-series study indicates that short-term exposure to air pollution (especially SO₂, NO₂, CO, and O₃) was positively correlated with EDVs for urolithiasis in Wuhan, China, and the effects varied by season, age and gender.