Ureteroscopy vs laparoscopic ureterolithotomy for large proximal ureteric stone: a randomised trial.

OBJECTIVE: To compare the outcomes of retrograde flexible ureteroscopy (fURS) with retroperitoneal laparoscopic ureterolithotomy (RLU) for large proximal ureteric stones. PATIENTS AND METHODS: A prospective randomised trial was conducted from January 2018 through December 2022 including patients with impacted proximal ureteric stones of 15-25 mm. Patients underwent fURS or RLU. Primary outcome was the stone-free rate. Demographic data, stone features, and complications rates were also compared between groups. RESULTS: A total of 64 patients were enrolled, 32 in each group. The mean impacted stone time was similar between groups, as well as stone size (17 mm) and stone density (>1000 Hounsfield Units). The ureteric stone-free rates between the two groups (93.7% in fURS vs 96.8% in RLU; odds ratio [OR] 0.72, 95% confidence interval [CI] -1.72 to 3.17; P = 0.554), and overall success rates, which take into account residual fragments in the kidney (84.3% in fURS vs 93.7% in RLU; OR 1.02, 95% CI -0.69 to 2.74; P = 0.23), were similar. Operative time was also not statistically significantly different between groups (median 80 vs 82 min; P = 0.101). There was no difference in hospital length of stay. Retropulsion rate was higher with fURS (65.6% vs 3.1%; p < 0.001). Residual hydronephrosis (34.3% each group) and complication rates did no differ according to treatment. CONCLUSION: Flexible URS and RLU are both highly efficient and present low morbidity for large impacted proximal ureteric stone treatment. RLU is not superior to fURS.

Patients undergoing double J substitution with a pigtail suture stent report a significant decrease of stent-related symptoms. Results from a prospective multicenter longitudinal trial.

PURPOSE: To compare stent-related symptoms (SRS) in patients with double J (DJ) undergoing substitution with a pigtail suture stent (PSS) after ureteroscopy (URS), through the Ureteral Stent Symptom Questionnaire (USSQ). MATERIALS AND METHODS: Patients with DJ undergoing URS for stone treatment were enrolled in this prospective multicenter longitudinal study. The USSQ was submitted thrice: 2 weeks after DJ, 2 weeks after PSS and 4 weeks after PSS removal (baseline). PRIMARY ENDPOINT: to compare Urinary Symptom Index Score and the rate of patients with pain 2 weeks after DJ and PSS. Secondary endpoints: to compare other USSQ scores and single answers 2 weeks after DJ and PSS, and DJ and PSS USSQ scores with baseline. RESULTS: 93 patients were enrolled. 2 weeks Urinary Symptom Index Score (p < 0.001) and the percentage of patients complaining of pain (60.2% vs 88.2%, p < 0.001) were significantly in favour of PSS compared to DJ. 2 weeks scores were significantly improved with PSS compared to DJ: Pain Index (p < 0.001), VAS (p < 0.001), General Health Index (p < 0.001) and Work Performance Index (p < 0.001). All urinary symptoms were significantly decreased with PSS, including renal pain during micturition and pain interfering with life. Pain Index Score (p = 0.622) and VAS (p = 0.169) were comparable to baseline with PSS, while differed with DJ. CONCLUSIONS: Patients undergoing DJ substitution with PSS after URS report a significant decrease of SRS. Urologists may consider positioning PSS after URS in pre-stented patients to reduce the impact of SRS.

A novel post-percutaneous nephrolithotomy sepsis prediction model using machine learning.

OBJECTIVES: To establish a predictive model for sepsis after percutaneous nephrolithotomy (PCNL) using machine learning to identify high-risk patients and enable early diagnosis and intervention by urologists. METHODS: A retrospective study including 694 patients who underwent PCNL was performed. A predictive model for sepsis using machine learning was constructed based on 22 preoperative and intraoperative parameters. RESULTS: Sepsis occurred in 45 of 694 patients, including 16 males (35.6%) and 29 females (64.4%). Data were randomly segregated into an 80% training set and a 20% validation set via 100-fold Monte Carlo cross-validation. The variables included in this study were highly independent. The model achieved good predictive power for postoperative sepsis (AUC = 0.89, 87.8% sensitivity, 86.9% specificity, and 87.4% accuracy). The top 10 variables that contributed to the model prediction were preoperative midstream urine bacterial culture, sex, days of preoperative antibiotic use, urinary nitrite, preoperative blood white blood cell (WBC), renal pyogenesis, staghorn stones, history of ipsilateral urologic surgery, cumulative stone diameters, and renal anatomic malformation. CONCLUSION: Our predictive model is suitable for sepsis estimation after PCNL and could effectively reduce the incidence of sepsis through early intervention.

Distribution and antimicrobial resistance patterns of urinary pathogens in preoperative midstream urine cultures from Chinese patients with urinary calculi: a meta-analysis.

BACKGROUND AND OBJECTIVE: This study comprehensively evaluates the distribution patterns and antimicrobial resistance profiles of urinary pathogens in Preoperative midstream urine cultures collected from patients with urinary calculi in China over the last two decades. METHODS: A cross-sectional analysis of 41 studies was conducted. A systematic search across various databases, including Wanfang Data, CNKI, SinoMed, Embase, PubMed, and Web of Science, was carried out, covering the time period from 2002 to 2022. Using R 4.2.1 software, a meta-analysis was performed to assess heterogeneity using Cochran's Q test and the I2 statistic. RESULTS: In the analysis of preoperative midstream urine cultures from Chinese patients with urinary calculi, gram-negative bacteria dominated at 69%, with Escherichia coli (43%), Klebsiella pneumoniae (8%), Proteus mirabilis (6%), Pseudomonas aeruginosa (5%), Acinetobacter baumannii (3%), and Enterobacter cloacae (4%) being prominent. Gram-positive organisms included Enterococcus faecalis (9%), Enterococcus faecium (5%), and Staphylococcus aureus (4%). Over time, proportions of Proteus mirabilis, Enterococcus faecalis, and Staphylococcus aureus decreased, while Klebsiella pneumoniae and Pseudomonas aeruginosa increased. Notably, Escherichia coli proportion reduced from 37 to 33% within the last two decades. Antimicrobial resistance analysis indicated declining resistance in E. coli (e.g., co-trimoxazole from 73 to 55%, gentamicin from 64 to 40%), but rising resistance in piperacillin and cefotaxime (34-60%). Enterococcus faecalis exhibited increasing resistance to ampicillin (5-69%), gentamicin (59-94%), and tetracycline (77-89%) over time, while resistance to levofloxacin and ciprofloxacin notably decreased (72-16% and 49-8%, respectively). CONCLUSION: Over the past two decades, the proportion of gram-negative bacteria was declined, while the proportion of gram-positive bacteria increased. Escherichia coli remained the most common pathogen in the urine culture of patients with urinary calculi in China and the resistance of Escherichia coli to commonly used antibiotics increased. Clinicians should select appropriate antibiotics according to the results of urine culture and drug sensitivity test to reduce the occurrence of antibiotic resistance.

Wisely Choosing a Fast-Food Burger Meal Results in Meaningful Reduction in Sodium: Implications for Kidney Stone Patients.

OBJECTIVE: Stone formers trying to limit dietary sodium may be unable to give up fast food. For the classic American hamburger, it is unclear if lower sodium preparations of this item are available and how this could affect sodium intake. We determined the impact of careful selection at national chains. METHODS: Nutritional guides for 14 national chains were analyzed for all beef-based burgers and french fries. A meal was defined as 1 burger and an order of fries. The daily sodium limit (recommended daily sodium allowance [RDA]) was considered to be 2,300 mg. The maximal sodium reduction was defined as the difference between the highest and lowest sodium-containing meals. The Kruskal-Wallis test with Dunn's method was used to compare food items among the chains. RESULTS: Of the total 263 different burgers and 74 different fries, median sodium was 1130 mg (range 180-3520) and 565 mg (range 30-1480), respectively. Mean sodium for burgers at individual chains ranged from a low of 590 mg to a high of 1721 mg (P < .001). The mean sodium for fries at individual chains ranged from a low of 245 mg to a high of 947 mg (P < .001). Post-hoc testing revealed 26 significant differences between pairs of restaurants for sodium content of burgers with P < .05 for each. The median maximal sodium reduction among the different chains was 1925 mg. Depending on the chain, sodium content of 1 meal could be reduced by as little as 830 mg (36% RDA) or as much as 3360 mg (146% RDA) by careful selection. CONCLUSION: Stone formers should be aware of significant variation in sodium content of burgers and fries among chains and within a chain. Wisely selecting just 1 fast-food burger meal can significantly reduce sodium intake.

Effect of Cannabidiol Oil on Post-ureteroscopy Pain for Urinary Calculi: A Randomized, Double-blind, Placebo-controlled Trial.

PURPOSE: Post-ureteroscopy stent placement carries significant morbidity which can interfere with daily life. This discomfort unfortunately leads to high utilization of opioid pain medications, which have a known risk of addiction. Cannabidiol oil represents an alternative analgesic that has proven anti-inflammatory and antinociceptive effects. The purpose was to evaluate the effect of a Food and Drug Administration-approved cannabidiol oil (Epidiolex) on pain control and opioid usage in the post-ureteroscopy setting. MATERIALS AND METHODS: This was a prospective, randomized, double-blind, placebo-controlled trial at a tertiary care center. Ninety patients undergoing ureteroscopy with stent placement for urinary stone disease were randomized 1:1 to placebo or 20 mg cannabidiol oil daily for 3 days postoperatively. Both groups were prescribed a rescue narcotic, tamsulosin, oxybutynin, and phenazopyridine. Daily pain scores, medication usage, and ureteral stent symptoms using the validated Ureteral Stent Symptom Questionnaire were recorded postoperatively. RESULTS: Both the placebo and cannabidiol oil groups were not different in pre- and perioperative characteristics. There was no difference in pain scores or opioid usage between groups postoperatively. The level of discomfort with ureteral stents was also not different between groups when comparing physical activity, sleep, urination, and activities of daily life. CONCLUSIONS: This randomized, blinded, placebo-controlled trial showed that cannabidiol oil is safe but ineffective when compared to placebo in reducing post-ureteroscopic stent discomfort or opioid usage. Despite the availability of numerous analgesic agents, stent symptoms continue to be a dissatisfier for most patients, suggesting additional work needs to focus on novel interventions and pain control.

Risk Factors for Increased Stent-associated Symptoms Following Ureteroscopy for Urinary Stones: Results From STENTS.

PURPOSE: The STudy to Enhance uNderstanding of sTent-associated Symptoms sought to identify risk factors for pain and urinary symptoms, as well as how these symptoms interfere with daily activities after ureteroscopy for stone treatment. MATERIALS AND METHODS: This prospective observational cohort study enrolled patients aged ≥12 years undergoing ureteroscopy with ureteral stent for stone treatment at 4 clinical centers. Participants reported symptoms at baseline; on postoperative days 1, 3, 5; at stent removal; and day 30 post-stent removal. Outcomes of pain intensity, pain interference, urinary symptoms, and bother were captured with multiple instruments. Multivariable analyses using mixed-effects linear regression models were identified characteristics associated with increased stent-associated symptoms. RESULTS: A total of 424 participants were enrolled. Mean age was 49 years (SD 17); 47% were female. Participants experienced a marked increase in stent-associated symptoms on postoperative day 1. While pain intensity decreased ∼50% from postoperative day 1 to postoperative day 5, interference due to pain remained persistently elevated. In multivariable analysis, older age was associated with lower pain intensity (P = .004). Having chronic pain conditions (P < .001), prior severe stent pain (P = .021), and depressive symptoms at baseline (P < .001) were each associated with higher pain intensity. Neither sex, stone location, ureteral access sheath use, nor stent characteristics were drivers of stent-associated symptoms. CONCLUSIONS: In this multicenter cohort, interference persisted even as pain intensity decreased. Patient factors (eg, age, depression) rather than surgical factors were associated with symptom intensity. These findings provide a foundation for patient-centered care and highlight potential targets for efforts to mitigate the burden of stent-associated symptoms.

Development and validation of the UCSS score, a novel method to predict septic shock after PCNL.

OBJECTIVE: To develop an objective and easily recognizable model to predict septic shock following percutaneous nephrolithotomy (PCNL). SUBJECTS AND METHODS: First, we identified differences between 431 patients who underwent PCNL with or without septic shock. These data were used to develop existing models and examine their improvement. Multivariate analysis was applied to identify risk factors of septic shock after PCNL based on the scores allocated to the PCNL postoperative test indicators. Finally, we developed a predictive nomogram using the selected factors and compared its performance with that of the existing nomograms SOFA, qSOFA, and SIRS. RESULTS: Twelve (2.8%) of the patients met the criteria for postoperative septic shock after PCNL. Baseline data analysis revealed differences in sex, preoperative drainage, urinary culture, and urinary leukocyte between groups. After transforming patient data into measurement-level data, we investigated each index score in these conditions, and found that the incidence of septic shock generally increased with the score. Multivariate analysis and early optimization screening revealed that septic shock factors could be predicted using platelets, leukocytes, bilirubin, and procalcitonin levels. We further compared the prediction accuracy of urinary calculi-associated septic shock (UCSS), SOFA, qSOFA, and SIRS scores using the AUC of the ROC curve. As compared to SIRS [AUC 0.938 (95% CI 0.910-0.959)] and qSOFA [AUC 0.930 (95% CI 0.901-0.952)], UCSS [AUC 0.974 (95% Cl 0.954-0.987)] and SOFA [AUC 0.974 (95% CI 0.954-0.987)] scored better at discriminating septic shock after PCNL. We further compared the ROC curves of UCSS with SOFA (95% CI - 0.800 to 0.0808, P = 0.992), qSOFA (95% CI - 0.0611 to 0.0808, P = 0.409), and SIRS (95% CI - 0.0703 to 0.144, P = 0.502), finding that UCSS was non-inferior to these models. CONCLUSIONS: UCSS, a new convenient and cost-effective model, can predict septic shock following PCNL and provide more accurate discriminative and corrective capability than existing models by including only objective data. The predictive value of UCSS for septic shock after PCNL was greater than that of qSOFA or SIRS scores.

Contrast-enhanced ultrasound versus conventional ultrasound-guided percutaneous nephrolithotomy in patients with a non-dilated collecting system: results of a pooled analysis of randomized controlled trials.

BACKGROUND: Contrast-enhanced ultrasound in percutaneous nephrolithotomy (CEUS-PCNL) is an economical and practical technique for the treatment of patients with renal stones without significant collecting system dilatation. The aim of this systematic review is to compare the safety and efficacy of CEUS-PCNL and conventional ultrasound (US)-guided (US-PCNL) treatment of patients with renal calculi without significant hydronephrosis. METHODS: This review was conducted with strict adherence to the PRISMA guidelines. Comparative studies on CEUS-PCNL and US-PCNL published in PubMed, SinoMed, Google Scholar, Embase, and Web of science until March 1, 2023, were systematically searched. RevMan 5.1 software was used for meta-analysis. Pooled odds ratios (ORs), weight mean differences (WMDs) and standard mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using the fixed-effects or random-effects model. Publication bias was evaluated using funnel plots. RESULTS: Four randomized controlled trials involving 334 patients (168 with CEUS-guided PCNL and 166 with US-guided PCNL) were identified. There was no statistically significant difference between CEUS-guided PCNL and US-guided PCNL in terms of the operation time (SMD: - 0.14; 95% CI - 0.35 to 0.08; p = 0.21), minor complications (p = 0.48), major complications (p = 0.28) and overall complications (p = 0.25). However, CEUS-guided PCNL had a higher stone-free rate (OR: 2.22; 95% CI 1.2 to 4.12; p = 0.01), higher success rate of single-needle punctures (OR:3.29; 95% CI 1.82 to 5.95; p < 0.0001), shorter puncture time (SMD: - 1.35; 95% CI - 1.9 to - 0.79; p < 0.00001), shorter hospital stay (SMD: - 0.34; 95% CI - 0.55 to - 0.12; p = 0.002) and lesser hemoglobin loss (SMD: - 0.83; 95% CI - 1.06 to - 0.61; p < 0.00001) as compared with conventional US-guided PCNL. CONCLUSIONS: According to almost all pooled data, CEUS-guided PCNL is superior to US-guided PCNL in terms of the perioperative outcomes. However, many rigorous clinical randomized controlled studies are required to obtain more accurate results. Registration The study protocol was registered with PROSPERO (CRD42022367060).

Drug resistance and influencing factors of biofilm bacteria in upper urinary calculi patients with double J stent indwelling.

OBJECTIVE: To analyze the distribution and drug resistance of biofilm bacteria infected with upper urinary calculi patients with double J stent indwelling, and to explore the influencing factors of Biofilm Bacteria Infections. METHODS: A total of 400 patients with upper urinary calculi who adopted double J stent inserting in our hospital from January 2019 to January 2022 were included. Urine and double J stent samples were collected, pathogen cultures were performed, and then drug sensitivity test analysis was carried out for isolates. Univariate and multivariate logistic regression analyzes were used to analyze the influencing factors of patients with double J stent associated biofilm bacteria infections. RESULTS: A total of 13 strains (3.2%) of biofilm bacteria were detected in urine samples and 168 strains (42%) in double J stent samples (P < 0.05), 95 strains (23.7%) of pathogenic bacteria were separated from urine samples and 117 strains (29.2%) from double J-stent samples (P > 0.05). Escherichia coli were the most common bacteria. There was significantly higher drug resistance observed in biofilm bacteria versus urine-cultured pathogens (P < 0.05). Advanced age, long-term catheterization, inadequate water intake, hypoproteinemia, abnormal renal function, and diabetes mellitus were independent risk factors for biofilm bacteria infection associated with double J stent(P < 0.05). CONCLUSION: Among the upper urinary calculi patients with double J stent indwelling, the positive rate and drug resistance of biofilm bacteria obtained from double J stent were significantly higher than that from urine. More attention should be paid to the factors that influence biofilm bacteria infections.

Risk factors for systemic inflammatory response syndrome after endoscopic lithotripsy for upper urinary calculi.

BACKGROUND: To explore the risk factors for systemic inflammatory response syndrome (SIRS) after endoscopic lithotripsy for upper urinary calculi. METHODS: This retrospective study included patients with upper urinary calculi who underwent endoscopic lithotripsy in the First Affiliated Hospital of Zhejiang University between June 2018 and May 2020. RESULTS: A total of 724 patients with upper urinary calculi were included. One hundred and fifty-three patients developed SIRS after the operation. The occurrence of SIRS was higher after percutaneous nephrolithotomy (PCNL) compared with ureteroscopy (URS) (24.6% vs. 8.6%, P < 0.001) and after flexible ureteroscopy compared with ureteroscopy (fURS) (17.9% vs. 8.6%, P = 0.042). In the univariable analyses, preoperative infection history (P < 0.001), positive preoperative urine culture (P < 0.001), history of kidney operation on the affected side (P = 0.049), staghorn calculi (P < 0.001), stone long diameter (P = 0.015), stone limited to the kidney (P = 0.006), PCNL (P = 0.001), operative time (P = 0.020), and percutaneous nephroscope channel (P = 0.015) were associated with SIRS. The multivariable analysis showed that positive preoperative urine culture [odds ratio (OR) = 2.23, 95% confidence interval (CI): 1.18-4.24, P = 0.014] and operative methods (PCNL vs. URS, OR = 2.59, 95% CI: 1.15-5.82, P = 0.012) were independently associated with SIRS. CONCLUSION: Positive preoperative urine culture and PCNL are independent risk factors for SIRS after endoscopic lithotripsy for upper urinary calculi.

Plasma formation in holmium:YAG laser lithotripsy.

OBJECTIVES: During holmium:yttrium-aluminum-garnet (holmium:YAG) laser lithotripsy to break urinary stones, urologists frequently see flashes of light. As infrared laser pulses are invisible, what is the source of light? Here we studied the origin, characteristics, and some effects of flashes of light in laser lithotripsy. METHODS: Ultrahigh-speed video-microscopy was used to record single laser pulses at 0.2-1.0 J energy lasered with 242 µm glass-core-diameter fibers in contact with whole surgically retrieved urinary stones and hydroxyapatite (HA)-coated glass slides in air and water. Acoustic transients were measured with a hydrophone. Visible-light and infrared photodetectors resolved temporal profiles of visible-light emission and infrared-laser pulses. RESULTS: Temporal profiles of laser pulses showed intensity spikes of various duration and amplitude. The pulses were seen to produce dim light and bright sparks with submicrosecond risetime. The spark produced by the intensity spike at the beginning of laser pulse generated a shock wave in the surrounding liquid. The subsequent sparks were in a vapor bubble and generated no shock waves. Sparks enhanced absorption of laser radiation, indicative of plasma formation and optical breakdown. The occurrence and number of sparks varied even with the same urinary stone. Sparks were consistently observed at laser energy >0.5 J with HA-coated glass slides. The slides broke or cracked by cavitation with sparks in 63 ± 15% of pulses (1.0 J, N = 60). No glass-slide breakage occurred without sparks (1.0 J, N = 500). CONCLUSION: Unappreciated in previous studies, plasma formation with free-running long-pulse holmium:YAG lasers can be an additional physical mechanism of action in laser procedures.

Predictive model for urosepsis in patients with Upper Urinary Tract Calculi based on ultrasonography and urinalysis using artificial intelligence learning.

PURPOSE: To construct a predicting model for urosepsis risk for patients with upper urinary tract calculi based on ultrasound and urinalysis. MATERIALS AND METHODS: A retrospective study was conducted in patients with upper urinary tract calculi admitted between January 2016 and January 2020. The patients were randomly grouped into the training and validation sets. The training set was used to identify the urosepsis risk factors and construct a risk prediction model based on ultrasound and urinalysis. The validation set was used to test the performance of the artificial neural network (ANN). RESULTS: Ultimately, 1716 patients (10.8% cases and 89.2% control) were included. Eight variables were selected for the model: sex, age, body temperature, diabetes history, urine leukocytes, urine nitrite, urine glucose, and degree of hydronephrosis. The area under the receiver operating curve in the validation and training sets was 0.945 (95% CI: 0.903-0.988) and 0.992 (95% CI: 0.988-0.997), respectively. Sensitivity, specificity, and Yuden index of the validation set (training set) were 80.4% (85.9%), 98.2% (99.0%), and 0.786 (0.849), respectively. CONCLUSIONS: A preliminary screening model for urosepsis based on ultrasound and urinalysis was constructed using ANN. The model could provide risk assessments for urosepsis in patients with upper urinary tract calculi.

Nomogram to predict the risk of adverse outcomes in patients with residual stones following percutaneous nephrolithotomy.

PURPOSE: To investigate the risk factors associated with adverse outcomes in patients with residual stones after percutaneous nephrolithotomy (PCNL) and to establish a nomogram to predict the probability of adverse outcomes based on these risk factors. METHODS: We conducted a retrospective review of 233 patients who underwent PCNL for upper urinary tract calculi and had postoperative residual stones. The patients were divided into two groups according to whether adverse outcomes occurred, and the risk factors for adverse outcomes were explored by univariate and multivariate analyses. Finally, we created a nomogram for predicting the risk of adverse outcomes in patients with residual stones after PCNL. RESULTS: In this study, adverse outcomes occurred in 125 (53.6%) patients. Multivariate logistic regression analysis indicated that the independent risk factors for adverse outcomes were the diameter of the postoperative residual stones (P < 0.001), a positive urine culture (P = 0.022), and previous stone surgery (P = 0.004). The above independent risk factors were used as variables to construct the nomogram. The nomogram model was internally validated. The calculated concordance index was 0.772. The Hosmer-Lemeshow goodness-of-fit test was performed (P > 0.05). The area under the ROC curve of this model was 0.772. CONCLUSIONS: Larger diameter of residual stones, positive urine culture, and previous stone surgery were significant predictors associated with adverse outcomes in patients with residual stones after PCNL. Our nomogram could help to assess the risk of adverse outcomes quickly and effectively in patients with residual stones after PCNL.

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.

The Consecutive 200 Cases of Endoscopic-Combined Intrarenal Surgery: Comparison between Standard and Miniature Surgeries.

Background and Objectives: Percutaneous nephrolithotomy (PCNL) is still the gold-standard treatment for large and/or complex renal stones. Endoscopic combined intrarenal surgery (ECIRS) was developed with the goal of minimizing the number of access tracts of PCNL while simultaneously improving the one-step stone-free rate (SFR). The aim of this study was to share the experience of the consecutive 200 cases of ECIRS in one institute and analyze surgical outcomes of mini-ECIRS and standard ECIRS. Materials and Methods: We performed ECIRS for 200 adult patients between July 2017 and January 2020. An ECIRS was performed with the patient under general anesthesia in the intermediate-supine position. Surgeries were finished using a tubeless technique with a simple ureteral stent insertion. Results: There were significant differences in the mean maximal stone length (MSL), the variation coefficient of stone density (VCSD), the linear calculus density (LCD), the Seoul National University Renal Stone Complexity (S-ReSC), and the modified S-ReSC scores in stone characteristics, and estimated blood loss (EBL) and operation time in peri-operative outcomes between conventional and mini-ECIRS. After propensity-score matching, there was only a difference in EBL between the two groups. In logistic regression models, MSL [odds ratio (OR) 0.953; 95% confidence interval (CI) 0.926-0.979; p < 0.001], LCD (OR 4.702; 95% CI 1.613-18.655; p = 0.013) were significant factors for the success rate after ECIRS. Conclusions: In patients who underwent a mini-ECIRS, the stones were relatively smaller and less complex, and the operation time was shorter. However, if the size of stones was similar, there was no difference in the success rate, but EBL was lower in mini-ECIRS than in standard surgery.

Serum procalcitonin, C-reactive protein, and neutrophil gelatinase-associated lipocalin in early diagnosis of acute kidney injury after upper urinary tract calculi.

Objective: To investigate the value of serum procalcitonin(PCT), C-reactive protein(CRP), and neutrophil gelatinase-associated lipocalin(NGAL) in the early diagnosis of acute kidney injury(AKI) after upper urinary tract calculi(UUTC). Methods: The clinical data of 86 patients who underwent UUTC surgery in our hospital from March 2020 to April 2021 were analyzed retrospectively(Approval number: 20211205L, Date: 2021-12-21). Patients were divided into an AKI group (AKI≥7 days after the operation) and a Non-AKI group. PCT, CRP, and NGAL concentrations were compared before and two hours after the operation. Multivariate logistic regression analysis was used to identify risk factors affecting the early occurrence of AKI post-operation. The receiver operating characteristic curve evaluated PCT, CRP, and NGAL in the early AKI diagnosis. Results: A total of 86 patients (30 with AKI and 56 with Non-AKI) were included. Kidney injury molecule-1(KIM-1) and urinary microalbumin(mAlb) concentrations were significantly higher in the AKI group (P<0.05). PCT, CRP, and NGAL concentrations were significantly higher two hours after the operation than before the operation (P<0.05). KIM-1 levels and elevated PCT, CRP and NGAL concentrations affected the establishment of AKI after UUTC. The sensitivity of PCT, CRP, and NGAL in evaluating AKI after UUTC were 81.17%, 84.42%, and 79.02%; the specificity was 62.31%, 71.48%, and 73.32%; and the AUC was 0.812, 0.885 and 0.804 respectively. Conclusions: PCT, CRP, and NGAL concentrations in patients with AKI after UUTC were significantly increased two hours after the operation, which can be used for the early diagnosis of AKI after UUTC operation.

Loop-tail stents fail in reducing stent-related symptoms: results of a prospective randomised controlled trial.

OBJECTIVE: To compare stent-related symptoms (SRS) of loop-tail (LT) and conventional double J (DJ) stents after uncomplicated flexible ureterorenoscopy (fURS), in a prospective randomised controlled single-blind parallel-group study. PATIENTS AND METHODS: Patients undergoing fURS were randomised into two groups: the LT Group received LT stents (Polaris™ Loop) and the DJ Group received conventional DJ stents (Vortek® ). The stent was removed after 4 weeks. The Ureteric Stent Symptom Questionnaire (USSQ) was administered at 2 days, 4 and 8 weeks (baseline evaluation) after stent insertion. The primary endpoint was to compare the Urinary Symptom Index Score of the LT vs DJ groups at 4 weeks after stent insertion. The secondary endpoints were to compare the USSQ domains' subscores at 2 days and 4 weeks after stent insertion, USSQ single answers at 4 weeks, and the 4-week USSQ domains' subscores adjusted for baseline. RESULTS: A total of 68 patients were randomised (34 LT and 34 DJ). The answers given at 4 weeks were not significantly different between the two groups for the Urinary Symptom Index Score (P = 0.982), Pain Index Score (P = 0.169), visual analogue scale (P = 0.276), and all the other domains of the USSQ. At 4 weeks, the single-answer analysis did not find any differences between the groups; the urinary symptoms were all comparable, as was the requirement for pain painkillers (P = 0.684) and pain during sex (P = 0.496). There were also no significant differences for every single domain score for the responses given at 2 days. The same applied to USSQ subscores at 4 weeks adjusted for the 8-week baseline results, which were also comparable. CONCLUSIONS: The study found no differences in terms of SRS between the LT and DJ groups, either at 2 days or 4 weeks after stent insertion, with or without baseline correction.

Sensitivity of virtual non-contrast dual-energy CT urogram for detection of urinary calculi: a systematic review and meta-analysis.

OBJECTIVE: To determine the sensitivity of dual-energy (DE) virtual non-contrast computed tomography (vNCT), generated from the excretory phase of a CT urogram, compared to true non-contrast CT (tNCT) for the detection of urinary calculi. METHODS: A search of multiple medical literature databases was performed using predetermined search terms. Inclusion and exclusion criteria were applied, and bias risk was assessed by two independent reviewers using the quality assessment of diagnostic accuracy studies (QUADAS) tool. Collated estimates of sensitivity were generated, and sources of heterogeneity were identified and reviewed. RESULTS: Thirteen studies (1760 patients; 1740 urinary calculi) were included for sensitivity assessment. Pooled sensitivity for urinary calculi on vNCT was 78.1% (95% CI: 70.2 to 85.0%); however, heterogeneity between studies was very high (I2 = 92.0%). Sources of heterogeneity between studies were explored through subgroup analysis by categorising studies according to slice thickness (≥ 2 mm and < 2 mm), use of oral hydration, and use of intravenous furosemide. Pooled sensitivity for detection of urinary calculi on vNCT for studies that used oral hydration and < 2 mm slice thickness was 92.2% (95% CI: 89.5 to 94.5%). Pooled specificity was not performed as true negatives were not reported in most studies. Potential sources of bias were identified in included studies. CONCLUSION: vNCT demonstrated a moderate pooled sensitivity compared to tNCT for the detection of urinary calculi in split bolus CT urogram protocols. However, subgroup analysis suggests higher sensitivity when employing oral hydration and < 2 mm slice thickness or increment. KEY POINTS: • vNCT demonstrated moderate pooled sensitivity for the detection of urinary calculi in split bolus CT urogram protocols. • Subgroup analysis suggested higher sensitivity with oral hydration and < 2 mm slice thickness or increment.

Construction of a novel rabbit model of ureteral calculi implanted with flowable resin.

BACKGROUND: The purpose of this study was to characterize the pathophysiological changes of hydronephrosis caused by ureteral calculi obstruction in a new rabbit ureteral calculi model by implanting flowable resin. METHODS: Forty New Zealand rabbits were randomly divided into two groups: the calculi group and the sham control group. In the calculi group (n = 20), rabbits were operated at left lower abdomen and the left ureter was exposed. Then flowable resin (flowable restorative dental materials) was injected into the left ureter using a 0.45 mm diameter intravenous infusion needle. Then light-cured for 40 s by means of a dental curing light to form calculi. In the sham control group, normal saline was injected into the ureter. Rabbits underwent X-ray and routine blood and urine tests preoperatively, as well as X-ray, CT, dissection, HE staining and routine blood and urine tests on 1, 3, 5 and 7 days postoperatively. Stone formation was assessed by X-ray and unenhanced CT scan after surgery. The pathophysiological changes were evaluated through dissection, HE staining and routine blood and urine tests. RESULTS: Ureteral calculi models were successfully constructed in 17 rabbits. In calculi group, high-density shadows were observed in the left lower abdomen on postoperative day 1st, 3rd, 5th and 7th by X-ray and CT scan. Dissection found obstruction formation of the left ureters, dilatation of the renal pelvis and upper ureter during 7 days after surgery. The renal long-diameters of the left ureters increased only on the 1st postoperative day. HE staining found ureteral and kidney damage after surgery. In calculi group and sham group,the serum creatinine, urea nitrogen, white blood cells and urine red blood cells were raised at day 1 after surgery. However, the indicators returned to normal at day 3, 5, and 7. CONCLUSIONS: This is a stable, less complicated operation and cost-effective ureteral calculi model by implanting flowable resin. And this novel model may allow us to further understand the pathophysiology changes caused by ureteral calculi obstruction.