Complications of ureteroscopy: a complete overview

Can preoperative transurethral catherization reduce the risk of urethral stricture after endoscopic treatment of the prostate?

Urethral strictures are a well-known complication following endoscopic treatment of benign prostatic hyperplasia (BPH). Although the exact cause remains unclear, repetitive instrument movement and pressure-induced ischemia are likely contributing factors. While the incidence seems lower after enucleation compared to transurethral resection of the prostate, it remains important to prevent this iatrogenic complication. A small randomized trial suggested a benefit from preoperative urethral dilatation, though findings were constrained by limited sample size and follow-up. Similarly, studies comparing resectoscope sizes have not yet demonstrated significant differences in stricture rates. Drawing parallels with ureteral stricture prevention, where prestenting with a ureteral catheter is commonly used, we hypothesize that preoperative transurethral catheterization may relax and dilate the urethra, potentially lowering the risk of stricture formation. Clinical observations support this: patients with preoperative indwelling catheters before endoscopic treatment of BPH often display a more compliant urethra during surgery. While mechanical irritation remains a theoretical concern of placing a catheter, the relaxing effect may outweigh potential harm, much like DJ-stent use in the ureter. A prospective study will be conducted within the EAU Endourology Consortium to evaluate this hypothesis, incorporating force-sensing dilators and standardized follow-up with uroflowmetry and cystoscopy at 3 and 6 months. If successful, preoperative catheterization may offer a simple, low-risk strategy to reduce urethral strictures in BPH surgery, particularly in patients with a narrow urethra.

Predictors and associations of complications in ureteroscopy for stone disease using AI: outcomes from the FLEXOR registry

We aimed to develop machine learning(ML) algorithms to evaluate complications of flexible ureteroscopy and laser lithotripsy(fURSL), providing a valid predictive model. 15 ML algorithms were trained on a large number fURSL data from > 6500 patients from the international FLEXOR database. fURSL complications included pelvicalyceal system(PCS) bleeding, ureteric/PCS injury, fever and sepsis. Pre-treatment characteristics served as input for ML training and testing. Correlation and logistic regression analysis were carried out by a multi-task neural network, while explainable AI was used for the predictive model. ML algorithms performed excellently. For intraoperative PCS bleeding, Extra Tree Classifier achieved the best accuracy at 95.03% (precision 80.99%), and greatest correlation with stone diameter(0.21) and residual fragments(0.26). PCS injury was best predicted by RandomForest (accuracy 97.72%, precision 63.50%). XGBoost performed best for ureteric injury (accuracy 96.88%, precision 60.67%). Both demonstrated moderate correlation with preoperative characteristics. Postoperative fever was predicted by Extra Tree Classifier with 91.34% accuracy (precision 58.20%). Cat Boost Classifier predicted postoperative sepsis with 99.15% accuracy (precision 66.38%), and the best overall performance. At logistic regression, postoperative fever/sepsis positively correlated with preoperative urine culture(p = 0.001). ML represents a powerful tool for automatic prediction of outcomes. Our study showed promises in algorithms training and validation on a very large database of patients treated for urolithiasis, with excellent accuracy for prediction of complications. With further research, reliable predictive nomograms could be created based on ML analysis, to serve as aid to urologists and patients in the decision making and treatment planning process.

A comparative study of mirabegron versus doxazosin in improving ureteral stent-related dysfunction

OBJECTIVE

To compare the efficacy of mirabegron and doxazosin in alleviating ureteral stent-related symptoms and sexual dysfunction.

METHOD

This study included 107 patients who provided informed consent and underwent transurethral ureteral lithotripsy with ureteral stent placement between January 2023 and December 2023. Patients were randomized into two groups receiving either mirabegron (50 mg/day) or doxazosin (4 mg/day). The Ureteral Stent Symptom Questionnaire (USSQ) scores and adverse drug reactions were recorded at baseline (ureteral stent placement), 2 weeks (ureteral stent removal), and 4 weeks (2 weeks after stent removal). The trial was registered with the Chinese Clinical Trial Registry (ChiCTR2500095161).

RESULTS

At 2 weeks, the mirabegron group showed a greater improvement in pain during intercourse compared to the doxazosin group (0.379 ± 0.186; p = 0.043). This improvement persisted at 4 weeks (0.363 ± 0.186). No significant differences were observed in sexual satisfaction scores between the groups at either time point (2 weeks: 0.175 ± 0.186, p = 0.350; 4 weeks: 0.157 ± 0.186, p = 0.401). Subgroup analysis revealed that mirabegron provided greater relief of pain during intercourse in women compared to doxazosin (OR = 14.40, 95% CI 1.53-135.51, p = 0.020). Additionally, women in the doxazosin group reported significantly lower sexual satisfaction compared to the mirabegron group (OR = 42.00, 95% CI 2.41-825.71, p = 0.014).

CONCLUSIONS

Mirabegron and doxazosin demonstrated similar efficacy in relieving ureteral stent-related symptoms. However, mirabegron offered a clear advantage in improving female sexual function, particularly regarding pain during intercourse and overall satisfaction.

A novel predictive method for URS and laser lithotripsy using machine learning and explainable AI: results from the FLEXOR international database

PURPOSE

We developed Machine learning (ML) algorithms to predict ureteroscopy (URS) outcomes, offering insights into diagnosis and treatment planning, personalised care and improved clinical decision-making.

METHODS

FLEXOR is a large international multicentric database including 6669 patients treated with URS for urolithiasis from 2015 to 2023. Preoperative and postoperative(PO) correlations were investigated through 15 ML-trained algorithms. Outcomes included stone free status (SFS, at 3-month imaging follow up), intraoperative (PCS bleeding, ureteric/PCS injury, need for postoperative drainage) and PO complications (fever, sepsis, need for reintervention). ML was applied for the prediction, correlation and logistic regression analysis. Explainable AI emphasizes key features and their contributions to the output.

RESULTS

Extra Tree Classifier achieved the best accuracy (81%) in predicting SFS. PCS bleed was negatively linked with 'positive urine culture'(-0.08), 'tamsulosin'(-0.08), 'stone location'(-0.10), 'fibre optic scope'(-0.19), 'Moses Fibre'(-0.09), and 'TFL'(-0.09), and positively with 'elevated creatine'(0.25), 'fever'(0.11), and 'stone diameter'(0.21). 'PCS injury' and 'ureteric injury' both showed moderate correlation with 'elevated creatinine'(0.11), 'fever'(0.10), and 'lower pole stone'(0.09). 'Tamsulosin'(0.23) use, presence of 'multiple'(0.25) or 'lower pole'(0.25) stones, 'reusable scope'(0.17) and 'Moses Fibre'(0.2546) increased the risk for PO stent, while 'digital scope'(-0.13) or 'TFL'(-0.29) reduced it. 'Preoperative fever'(0.10), 'positive urine culture'(0.16), and 'stone diameter'(0.10) may play a role in 'PO fever' and 'sepsis'. SFS was mainly influenced by 'age'(0.12), 'preoperative fever'(0.09), 'multiple stones'(0.15), 'stone diameter'(0.17), 'Moses Fibre"(0.15) and 'TFL'(-0.28).

CONCLUSION

ML is valuable tool for accurately predicting outcomes by analysing pre-existing datasets. Our model demonstrated strong performance in outcomes and risks prediction, laying the groundwork for development of accessible predictive models.

Early clinical outcomes using a 6.3 Fr single use ureteroscope compared to a 7.5 Fr device

Flexible ureteroscopy is a cornerstone in minimally invasive urology, providing effective management of kidney stones and other urological conditions. The emergence of single-use ureteroscopes addresses challenges associated with reusable devices, such as cross-contamination, maintenance costs, and degradation over time. This prospective, single-center study compared the performance of the 6.3 Fr single-use flexible ureteroscope to the 7.5 Fr model in the treatment of kidney stones ≤ 2 cm. Forty patients were divided into two groups of 20, with preoperative assessments including CT scans and urine cultures. All patients underwent flexible ureteroscopy with thulium fiber laser lithotripsy under general anesthesia, and stone-free rates (SFRs) were assessed via CT at one month postoperatively. The 6.3 Fr ureteroscope achieved a significantly higher SFR of 95% compared to 92.9% with the 7.5 Fr model (p = 0.042). Mean operative times were 58 min (6.3 Fr) vs. 62.5 min (7.5 Fr), with no statistically significant differences in laser time or total energy used. Energy efficiency was 0.047 mm3/J (6.3 Fr) vs. 0.035 mm3/J (7.5 Fr), while energy consumption was 20.89 J/mm3 vs. 28.34 J/mm3, respectively. Both devices exhibited low complication rates, with only minor complications (Clavien-Dindo grades 1 and 2) reported. Postoperative ureteral mucosal injury was assessed intraoperatively, and no cases exceeded Grade 1. This study highlights the safety and efficacy of the 6.3 Fr ureteroscope, demonstrating comparable or superior outcomes to the 7.5 Fr model in terms of SFR and operative time. While economic and sterility benefits were not evaluated, the findings support the adoption of smaller-diameter devices for minimally invasive procedures, though further studies are warranted to validate their broader clinical impact.

Medical malpractice related to urology: an analysis of court decisions in Turkey

OBJECTIVES

The aim of this study is to examine the lawsuits filed against urologists in Turkey, to reveal the results of these lawsuits and the sub-branch of urology they are related to, to discuss the possible reasons for the lawsuits and what can be done to prevent them.

MATERIALS AND METHODS

The case outcomes obtained using the keyword "Urology" from the publicly accessible official website of the Presidency of the Supreme Court of the Republic of Turkey between 2018 and 2024 were analyzed by two expert urologists.

RESULTS

Of the 215 cases reviewed, the outcomes of 25 cases that met our inclusion criteria were analyzed. Sixteen of these cases were filed against private hospitals. Fourteen of the Supreme Court rulings involved civil (compensation) lawsuits, while 11 were criminal cases. Thirteen cases were related to endourology, and 9 patients had urinary system stone disease. Seventeen of the lawsuits involved allegations of postoperative medical errors. Five cases were attributed to procedural skill errors, and four were due to a lack of informed consent. Complications led to the death of seven patients. The decisions of the first-instance courts resulted in 12 acquittals, 7 compensation rulings, and 6 criminal convictions. At the Supreme Court level, 12 cases were ruled against the physicians.

CONCLUSIONS

Nearly half of the cases resulted in rulings against urologists, with the majority being related to endourology. Our study emphasizes the importance of adhering to international medical guidelines, providing informed consent to patients, and carefully conducting postoperative follow-ups.

Diagnostic accuracy of Bladder EpiCheck for upper tract urothelial carcinoma: A meta-analysis

INTRODUCTION AND OBJECTIVE

Current upper tract urothelial carcinoma (UTUC) diagnosis and disease management rely on the combination of CT Urography (CTU), cytology and ureteroscopy (URS). The limited accuracy and complications associated with these tools have led to the search for non-invasive and reliable biomarkers. Our aim was to review and analyse the existing data on the use of Bladder EpiCheck® to assess its performance as a diagnostic tool for UTUC.

MATERIAL AND METHODS

A literature search on the diagnostic value of Bladder EpiCheck® as a urinary biomarker in UTUC was conducted through PubMed, Web of Science and Scopus until February 2024. Pooled sensitivity (Se), specificity (Sp), negative predictive value (NPV) and positive predictive value (PPV) of the biomarker were calculated. Diagnostic performance was assessed through the area under the curve (AUC).

RESULTS

Four studies, including 334 patients, were included in the quantitative analysis. Bladder EpiCheck® showed promising pooled diagnostic values with Se of 0.85 (95% CI 0.55-0.96), Sp of 0.93 (95% CI 0.56-0.99), PPV of 0.74 (95% CI 0.54-0.87) and NPV of 0.84 (95% CI 0.77-0.89). The exact AUC obtained was 0.912.

CONCLUSIONS

Bladder EpiCheck® is an effective diagnostic tool in UTUC, showing a promising diagnostic accuracy, with a Se and NPV of 85% and 84%, respectively. Its use in UTUC diagnosis and follow-up could reduce or postpone the need for more invasive procedures, such as URS, thereby reducing the procedure-associated risks and improving patients' quality of life. Although further research and large prospective studies are needed, the current results indicate that Bladder EpiCheck® is a promising tool in UTUC diagnosis, treatment decision-making, and follow-up.

Risk Factors for Adverse Outcomes Following Ureteroscopy for Stone Management in US Medicare Patients

OBJECTIVE

To evaluate the proportion of US Medicare patients undergoing ureteroscopy (URS) for kidney stone management at risk for adverse outcomes and analyze the association between risk factors and adverse events.

METHODS

Data from Medicare patients aged ≥65 who underwent URS between 2019 and 2023 were analyzed. Nine risk factors were examined for their prevalence and association with sepsis and intensive care unit (ICU) admission within 30 days, extended length of stay (LOS) during the index procedure, and death within 90 days.

RESULTS

Among 290,610 Medicare patients who underwent URS, 94.4% had ≥1 (n = 274,396) and 76.3% had ≥2 risk factors. The proportion of patients with each risk factor was: age over 70 (64.6%), preoperative stent (59.4%), female (46.4%), urinary tract infection within 3 months (39.1%), diabetes (33.0%), history of sepsis (17.3%), multiple urinary tract infections within 6 months (13.1%), Charlson Comorbidity Index score of ≥7 (10.2%), and ischemic heart disease (2.9%). Patients with risk factors experienced a higher incidence of adverse outcomes. Notably, among patients with sepsis history, the incidence of sepsis, ICU admission within 30 days, and death within 90 days were 30.3%, 2.5%, and 0.86%, respectively, versus, 2.2%, 0.80%, and 0.18% without sepsis history (all P <.001). Median LOS was 5 days among patients with sepsis history versus 3 days without (P <.001).

CONCLUSION

Most URS Medicare patients had risk factors. Those with risk factors were more likely to experience sepsis, ICU admission, prolonged hospital LOS, and death. These findings underscore the need for targeted prevention and careful management for high-risk URS patients.

European Association of Urology Guidelines on the Diagnosis and Treatment of Urolithiasis

BACKGROUND AND OBJECTIVE

The European Association of Urology urolithiasis guidelines provide evidence-based recommendations for the diagnosis and treatment of urinary stone disease. Given the complexity and variability of stone formation, individualised patient management is emphasised.

METHODS

The guidelines incorporate evidence from the latest research and focus on risk assessment, imaging techniques, pharmacological management, and surgical interventions. A research librarian conducted literature searches for urolithiasis in the Cochrane Library, Medline, and Embase databases via Dialog-Datastar. The strength of recommendations is also rated.

KEY FINDINGS AND LIMITATIONS

Diagnosis relies on a combination of clinical history, biochemical evaluation, and imaging, with ultrasound as the first-line modality and low-dose computed tomography as the gold standard for precise stone assessment. Stone composition and burden influence treatment decisions with algorithms primarily based on stone size, location, and composition. Nonsteroidal anti-inflammatory drugs are recommended for first-line pain management, with opioids reserved as a secondary option. Medical expulsive therapy with α-blockers may be considered for selected patients with ureteral stones. Extracorporeal shockwave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy remain the primary intervention modalities, with selection based on stone characteristics and patient factors. Advances in multiplanar imaging have improved assessment of the stone burden, although further research is needed to refine predictive models. Genetic testing is recommended for high-risk patients to guide personalised treatment.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The guidelines provide a framework for clinical decision-making while acknowledging the need for continued advances in urolithiasis.

With great power comes great risk: High ureteral stricture rate after high-power, high-frequency Thulium fiber laser lithotripsy in ureteroscopy

PURPOSE

To compare the safety and efficacy of Thulium Fiber Laser (TFL) using either manufacturer presets (MP) or individualized presets (IP) in ureteroscopy.

METHODS

Multi-institutional, retrospective analysis on the first patients treated with SOLTIVE® Premium (Olympus Medical Systems®) TFL in Switzerland in 2020. MP were used at the University Hospital of Geneva, while IP were used at the University Hospital of Zurich. Patient demographics, stone characteristics, and procedural details were collected. Primary outcome was postoperative ureteral stricture (US). Secondary outcome was stone-free rate (SFR).

RESULTS

A total of 158 patients were analyzed, 79 in each group. Demographics were similar between the two groups, except for a lower pre-stenting rate in the MP group (56% vs. 91%; p < 0.001) and a higher rate of ureteral access sheath use in the MP group (65% vs. 44%; p = 0.011). No significant differences in stone burden (median stone diameter 9 mm, median stone volume 267 mm3), nor in the rate of impacted ureteral stones (29% vs. 34%; p = 0.49). Mean power, maximal power, frequency settings, and energy consumption were significantly higher in the MP group. US rate was 11% in MP group compared to 1% in IP group (p = 0.009). MP were a significant predictor of US on multivariable analysis (OR 12.4; p = 0.02), independently from impacted ureteral stones. No difference in SFR between groups (85% and 84%; p = 0.67).

CONCLUSION

High-power, high-frequency laser settings from manufacturer laser presets increase the risk of US, without improving SFR. Future studies shall further evaluate optimal laser settings depending on patient characteristics and intraoperative situation.

Development of an Alginate Gel Composite with Antibacterial Properties Capable of Binding Calcium-Based Residual Stone Fragments in Endoscopic Stone Surgery

Background: Complete removal of urinary stones remains a challenge, as residual fragments can contribute to recurrence and postoperative urinary tract infections. This study presents an initial laboratory investigation into the development of an alginate gel composite designed to bind calcium-based stone remnants and exhibit antibacterial properties. Methods: To evaluate gel formation, calcium oxalate powder reagent and sodium alginate (SA) powder reagent were mixed in a Becker glass and stirred on a hot plate. Stones from 17 patients who underwent stone surgery were crushed, and gel formation was confirmed using the same experimental conditions with SA powder reagent. A gel composite material containing silver nitrate and vancomycin was prepared, and antibacterial activity against Staphylococcus aureus and Escherichia coli was tested over a 5-minute period. A mixture of 0.5 g alginic acid and 0.05 g calcium oxalate monohydrate powder reagent with 50 mL distilled water formed a gel after 30 minutes. Results: Sandy stones composed of calcium oxalate formed a better gel composite when mixed with SA than those composed of uric acid. In the antibacterial test of the alginate gel composite containing silver nitrate and vancomycin against S. aureus and E. coli, the number of live bacteria in the control and alginate gel composite was 3.5 × 103 and <10, respectively. Conclusion: This study represents a preliminary laboratory investigation into the development of an alginate gel composite for potential use in urinary stone management. Further preclinical studies are necessary to evaluate its efficacy and safety before clinical translation.

Is fluoroless retrograde intrarenal surgery safe and feasible in uncomplicated ureteral and renal stones? A single-center large series study

INTRODUCTION

Aimed to investigate the feasibility and availability of fluoroless retrograde intrarenal surgery (fRIRS) in a large patient population.

METHODS

Patients who underwent fRIRS for ureteral or renal calculi in our center between June 2019 and June 2024 were reviewed. Demographic data, stone characteristics, operation time, perioperative-postoperative complications, perioperative complications, and stone-free rates of patients who underwent fRIRS for ureteral or renal calculi were evaluated. Claven-Dindo classification was used for complications. All procedures were performed under spinal or general anesthesia.

RESULTS

1079 patients were included in the study. Of the 1079 patients, 352 (32.6%) were female and 727 (67.4%) were male. The mean age was 47.33 ± 14.31 years. The mean size of the stones was 13.1 ± 6.33 mm3. Of the patients, 208 (19.27%) received general anesthesia and 871 (80.73%) received spinal anesthesia. The mean operation time was 37.14 ± 17.65 min. All patients received a Double J (DJ) stent postoperatively. The rate of complications was 8% overall. The complications observed in general were minor; postoperative colic pain and hematuria were observed in 36 (3.3%) patients and 26 (2.4%) patients, respectively. Stone-free rate was 86.4%.

CONCLUSION

The fRIRS is a safe and feasible method for the treatment of uncomplicated ureteral and renal calculi. In uncomplicated patients, it has similar complication and success rates to conventional methods and eliminates radiation exposure.

Neutrophil to lymphocyte ratio in urolithiasis: a systematic review

BACKGROUND

Urolithiasis is among the most prevalent and possibly devastating diseases. It affects millions worldwide, and a cheap or rapid biomarker is required to diagnose it. Previous investigations revealed that inflammation has a role in the progression of urolithiasis patients, and an elevated neutrophil-to-lymphocyte ratio (NLR) value can be a valuable biomarker to ensure inflammation and, consequently, renal stones. This study was conducted to summarize the results of studies investigating the role of NLR in urolithiasis.

METHODS

We systematically searched three main databases (Scopus, PubMed, and Web of Science) up to January 1, 2023. Our study was registered in PROSPERO (CRD42024500756).

RESULTS

Ultimately, 33 studies were selected for this review article. Patients in either acute or subacute phase exhibited higher NLR levels than healthy controls. Also, patients in acute and subacute phases significantly differed regarding NLR levels. In addition, studies showed that NLR could predict sepsis and systemic inflammatory response syndrome (SIRS) among urolithiasis patients. In addition, evidence reported that NLR was helpful in the prediction of spontaneous stone passage among these patients.

CONCLUSION

Our results support a reliable biomarker that is easily added into clinical settings to help predict urolithiasis patients' condition.

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

OBJECTIVES

To evaluate the safety and efficacy of total tubeless percutaneous nephrolithotomy (PCNL) without retrograde insertion of a ureteral catheter for the treatment of kidney stone patients without hydronephrosis.

METHODS

This prospective randomized controlled study at a tertiary care medical center was conducted from August 2019 to April 2023. Kidney stone patients diagnosed by computed tomography (CT) without significant hydronephrosis were randomly assigned to two groups: total tubeless PCNL without retrograde insertion of a ureteral catheter (group 1) and traditional PCNL (group 2). The primary endpoint was postoperative complications, while the secondary endpoints included the stone-free rate (SFR), operative time, length of postoperative hospital stay, and medical costs.

RESULTS

A total of 99 patients were recruited, including 50 patients in group 1 and 49 patients in group 2. There were no significant differences in postoperative complications and SFR between the two groups (P > 0.05). However, relative to group 2, patients in group 1 had significantly shorter operative time (58.5 ± 25.39 min vs. 82.98 ± 26.02 min, P < 0.001) and length of postoperative hospital stay (1.98 ± 1.72 days vs. 4.39 ± 2.95 days, P < 0.001), as well as significantly lower medical costs (3190.30 ± 590.58 dollars vs. 3552.78 ± 967.79 dollars, P = 0.03).

CONCLUSION

Total tubeless PCNL without retrograde insertion of a ureteral catheter for the treatment of kidney stone patients without hydronephrosis is safe and effective for urologists with extensive experience in PCNL.

TRIAL REGISTRATION

chictr.org.cn identifier, ChiCTR2000040884, date of registration: 13/12/2020, retrospectively registered.

Risk factors for readmission after ureteroscopy for stone disease: Modern single centre experience

Objectives

To identify factors that increase a patient's risk of readmission in the immediate postoperative period following ureteroscopy.

Materials and Methods

An IRB-approved surgical database of patients with renal and ureteral stones at a single institution was retrospectively analysed for patients who underwent ureteroscopies and had 30 days follow-up from September 2016 to June 2019. We reviewed the most recent 600 cases (300 consecutive women and 300 consecutive men). Patient characteristics including gender, body mass index (BMI) and comorbidities (hypertension, gout, diabetes mellitus (DM), recurrent urinary tract infections (UTIs), chronic kidney disease (CKD), bowel disease), history of preoperative ED visit and surgical factors (preoperative stent, stone size) were used to conduct univariate and multivariable logistic regression analysis. Outcome measures included readmission within 30 days postoperatively. Exclusion criteria included age <18 and <30 days follow-up.

Results

Of the 600 patients, 40 (6.7%) visited the ED and 16 (2.7%) were admitted within 30 days postoperatively. None of the patient characteristics or surgical factors we examined were associated with ED visits postoperatively (all p > 0.05). Patients were more likely to have a postoperative admission if they were older (age 68 ± 15 vs 56 ± 15, p < 0.002; OR 1.06; 95% CI 1.01-1.10, p = 0.01) or had a history of recurrent UTIs (OR 7.40, 95%CI 1.78-30.67, p = 0.006). No other factors correlated with postoperative admissions.

Conclusions

Older age and history of recurrent UTIs increased patients' risks of readmission within 30 days of ureteroscopy. This finding is particularly important when hospital beds are at a premium. Older patients and patients with recurrent UTIs should be targeted for preoperative interventions to prevent readmission.

New Techniques and Technologies in Flexible Ureteroscopy

This article provides a step-by-step guide to flexible ureteroscopy (URS), with focus on some of the newer techniques and technologies available to facilitate treatment of complex stones. In it we review indications, preoperative evaluation, surgical steps, postoperative care, troubleshooting methods, and complication management. Furthermore, we will explore advances in laser technologies, the integration of suction mechanisms, and the incorporation of intrarenal pressure measurement systems in flexible URS.

Pseudoaneurysm of the lower pole segmental artery of the kidney following open nephrolithotomy using an avascular approach: a case report

Aneurysms are abnormalities in blood vessels that can be categorized as true aneurysms or pseudoaneurysms. Pseudoaneurysms occur when one or more layers of the blood vessel wall rupture, often as a result of trauma or medical procedures, such as nephrolithotomy. This case study discusses a pseudoaneurysm of the lower pole segmental artery of the kidney that developed after an open nephrolithotomy despite an avascular surgical plan. The patient experienced intermittent gross hematuria, highlighting the potential complications associated with renal surgeries. The diagnosis was challenging, necessitating a high suspicion index and imaging modalities such as ultrasound, CT scans, and angiography. Treatment options varied from conservative management to angioembolization, which is preferred for its minimally invasive nature and ability to preserve renal parenchyma. This study aims to demonstrate that the risk of pseudoaneurysm should be considered even in an atrophic nephrolithotomy performed without vascular invasion.

Effects of Ciprofol and Propofol General Anesthesia on Postoperative Recovery Quality in Patients Undergoing Ureteroscopy: A Randomized, Controlled, Double-Blind Clinical Trial

Objective

This study compares postoperative recovery quality between Ciprofol and Propofol, providing a reference for the clinical application of anesthetics.

Methods

We randomized 112 patients undergoing ureteroscopic surgery into two groups: the Ciprofol group (Group C), with an induction dose of 0.4 mg/kg and a maintenance dose of 0.8-1.5 mg/(kg·h), and the Propofol group (Group P), with an induction dose of 2 mg/kg and a maintenance dose of 4-10 mg/(kg·h). Both groups received sevoflurane at a concentration of 1%. The Bispectral Index (BIS) was maintained between 40 and 60. The primary outcomes were the Quality of Recovery-15 (QoR-15) scores on postoperative day 1 (POD1). Secondary outcomes included hemodynamic parameters, vasopressor use, timing indicators, sedative consumption, BIS values, Riker Sedation-Agitation Scale (R-SAS) scores, urinary tract symptoms, patient satisfaction, and adverse events.

Results

No significant differences were observed in QoR-15 scores between the two groups. Although Group C had higher pain (P = 0.004) and comfort (P = 0.002) scores on POD1, these differences were not clinically significant. The incidence of hypotension and vasopressor use was lower in Group C, which had more stable hemodynamics. Additionally, the time from induction to BIS ≤ 60 was shorter in Group P (P = 0.001), while Group C had lower BIS values from drug discontinuation to full recovery of consciousness (P = 0.001). The incidence of urinary tract symptoms on POD1 was lower in Group C (P = 0.043). There were no significant differences in time to spontaneous breathing recovery, extubation, recovery room stay, time to first ambulation, hospital stay, patient satisfaction, or other adverse events.

Conclusion

Ciprofol provides comparable early postoperative recovery to Propofol during ureteroscopy and may be a preferable alternative for urological procedures, especially in patients with blood pressure concerns.

Trial Registration

Chinese Clinical Trial Registry (ChiCTR2400082736).

Innovative approaches to large lower calyceal stones (10-20 mm): evaluating modified T-tilt position and lower calyx hydrodilatation techniques in flexible ureteroscopy versus hydrodilatation alone: prospective randomized controlled study

BACKGROUND

Managing lower calyceal stones poses significant challenges. Flexible ureteroscopy and laser lithotripsy (FURSL) are standard techniques for treating large stones (10-20 mm).

OBJECTIVE

This study evaluates the role of the T-tilt position (45-degree Trendelenburg with a 45-degree lateral tilt against the side of the stone) and hydrodilatation of the lower calyx with 50 cc saline injection as needed in optimizing stone-free rates and safety during FURSL for lower calyceal stones.

METHODS

Following ethical approval, a prospective randomized study with 197 patients was conducted. 13 patients were excluded (9 with renal anomalies or prior surgeries affecting anatomy, and four who refused participation). The remaining 184 were randomized into Group A (92 patients in T-tilt with hydrodilatation) and Group B (92 patients with hydrodilatation in lithotomy position). Randomization was achieved with computer-generated numbers stored in sealed envelopes. All patients had 10-20 mm stones and underwent FURSL using a 7.5 FR flexible ureteroscope and 200-micron Wolf laser fiber. Follow-up CT KUB was performed at 1 and 3 months, assessing stone-free status (no residual stones or residual < 3 mm) and the need for auxiliary procedures.

RESULTS

Both groups were statistically analyzed for age, sex, BMI, stone size, Hounsfield units (HU), infundibular dimensions, access sheath use, complications (fever, sepsis, hematuria) and hospital stay. No significant differences were found between the two groups in these variables. However, operative time was significantly longer in Group A than in Group B (P value = 0.018). The need for auxiliary procedures was significantly lower in Group A than in Group B (P value = 0.001), and the success rate was significantly higher in Group A than in Group B (P value = 0.001).

CONCLUSION

The T-tilt position and hydrodilatation significantly optimize outcomes and enhance stone-free rates for large lower calyceal stones (10-20 mm). This position improves intraoperative vision and facilitates access to the lower calyx, facilitating the clearance of stone fragments.

Real time monitoring of intrarenal pressures while using the flexible and navigable suction ureteral access sheath

PURPOSE

To report on in-vivo intrarenal pressure (IRP) during flexible ureteroscopy for treatment of kidney stones while using the novel flexible and navigable suction ureteral access sheath (FANS).

METHODS

A retrospective observational analysis was performed for 25 patients undergoing routine flexible ureteroscopy for treatment of renal stones between February 2024 and June 2024 from two centres in Canada. The LithoVue Elite™ ureteroscope (Boston Scientific Corp., Marlborough, MA, USA) with pressure sensing capability was used together with the Clearpetra® Ureteral Access Sheath System (Well Lead Medical Co. Ltd., Guangzhou, China) for all cases. Irrigation was via a pressure bag set at 250mmHg where possible and the access sheath was connected to wall suction at 200mmHg. Median and maximum IRP, as well as the distribution of cumulative procedure times according to various IRP ranges were analyzed.

RESULTS

The median age of the patients was 56 years, with a median BMI of 26.7 kg/m2. The median (Interquartile range {IQR}) IRP for all the cases was 22.0 (15.0-36.5) mmHg, with a median (IQR) procedure time of 35.9 (16.4-54.8) minutes. The IRP remained below 40mmHg in 76.2% of the total time in all procedures, and was below 60mmHg in 94.1% of the time. Significant variables associated with lower IRP were having a prior endourological procedure, pre-stenting, larger ureteral access sheath size and use of pre-operative alpha blocker. Age, BMI and total stone volume did not significantly affect IRP.

CONCLUSIONS

Low intrarenal pressures can be achieved with the use of FANS, even with higher irrigation pressures. Alpha blocker use, larger sheath size, prior endourological procedures and pre-stenting are all associated with lower IRP.

Effect of indwelling ureteral stents on sexual function: a real-world observational study

BACKGROUND

Ureteral DJ stents are commonly used devices in urology. However, stent placement may cause LUTS and affect the quality of life. We evaluated the direct relationship between ureteral stents and sexual function.

METHODS

From October 2022 to December 2023, 82 male and 90 female sexually active patients who underwent ureteroscopy at Beijing Tiantan Hospital, Capital Medical University, were enrolled. The basic information, surgical data, and two questionnaire data including the International Index of Erectile Function-5 and the Female Sexual Function Index of patients before the operation (baseline, T0), on the day of the ureteral DJ tube extraction (T1), and 4 weeks after ureteral DJ tube extraction (T2) were collected to analyze the changes in the patients' sexual function.

RESULTS

The average age of male patients was 36 years and of female patients 39 years. Before the ureteral DJ stent placement, the mean ± SD IIEF-5 score was 22.86 ± 0.91, and the average FSFI score was 31.66 ± 1.44. On the day of the ureteral DJ stent removal, the IIEF-5 score was 16.37 ± 2.62 (p < 0.01) and the FSFI score was 15.83 ± 4.05 (p < 0.01). Four weeks after ureteral DJ stent removal, the average IIEF-5 score was 22.77 ± 1.06 (p = 0.61) and the average FSFI score was 30.99 ± 1.79 (p = 0.78).

CONCLUSIONS

Indwelling ureteral stents after ureteroscopy can temporarily affect the sexual function of both male and female patients, typically recovering within 4 weeks after stent removal.

The application of new type ureteroscope and traditional linear ureteroscope in ureteric stone patients

OBJECTIVE

A ureteric stone is a type of urinary tract stone that is found within the ureter. While most cases can be managed with conservative treatment or minimally invasive surgery, these methods often cause significant pain for the patient. Interestingly, a new type of ureteroscope has shown considerable promise in treating patients with ureteric stones, and this study aims to explore its clinical application.

METHODS

A total of 120 patients with ureteric stones were recruited from our hospitals between January 1, 2023, and December 31, 2023. These patients were randomly assigned to either the control group, which received the traditional straight ureteroscope, or the experimental group, which was treated with the new type of ureteroscope. Both groups provided general data and blood samples for further analysis. A logistic regression analysis was conducted to examine the factors influencing infection following surgery in patients with ureteric stones, including preoperative CRP greater than 8 mg/L, postoperative CRP greater than 8 mg/L, preoperative white blood cell count (> 109/L), postoperative white blood cell count (> 109/L), preoperative urinalysis count greater than 28 (/ul), postoperative urinalysis count greater than 28 (/ul), and urine routine leukocyte count.

RESULTS

The findings indicated no significant differences between the observation group and the control group regarding preoperative demographic, participants general data (P > 0.05). Postoperative CRP > 8 mg/L, white blood cell count > 10 × 109/L, urinalysis count > 28/µL, and urine leukocyte count significantly decreased in the experimental group compared to the control group (P < 0.05). Binary logistic regression showed that postoperative CRP > 8 mg/L (OR = 7.03), white blood cell count > 109/L (OR = 3.86), urinalysis count > 28/µL (OR = 2.83), and urine leukocyte count (OR = 1.004) were predictive factors for ureteric stones. Preoperative values showed no significant difference (P > 0.05).

CONCLUSIONS

The binary logistic regression analysis identified Postoperative CRP > 8 mg/L, white blood cell count > 10 × 109/L, urinalysis count > 28/µL, and urine leukocyte count as significant predictors of postoperative infections. Our research findings indicate that the new ureteroscope has significant advantages over traditional ureteroscopes in terms of ease of entry into the ureteral lumen, stone fragmentation angle during surgery, surgical field of view, surgical operability, and reducing the risk of postoperative potential infections. These characteristics demonstrate that the new ureteroscope has significant potential in clinical applications, warranting further promotion and use.

Harnessing magnetism: evaluation of safety, tolerance and feasibility of magnetic kidney stone retrieval in vivo in porcine models

The primary objective of urolithiasis therapy is complete stone removal and highest stone-clearance rates possible to minimize recurrence. A novel approach that employs a magnetic suspension and a magnetic probe for the passive collection and removal of small residual fragments was developed. This study assessed the feasibility of this system in porcine models. Five female domestic pigs underwent retrograde intrarenal surgery under general anaesthesia to assess the new magnetic system. Pre-analysed human calculi were endoscopically inserted and comminuted using lithotripsy. The magnetic suspension was applied, and the magnetic-stone fragment complex was extracted. After nephrectomy, independent blinded pathologists evaluated all the kidneys. Safety and tolerance assessments revealed no adverse events (i.e. no complications on the Clavien-Dindo scale > 1) or complications associated with treatment. This study revealed superficial urothelial damage in all animals, characterized by desquamation and inflammation, caused primarily by the insertion of access sheaths and laser lithotripsy. Residual magnetic particles were observed in the renal pelvis but did not show signs of toxicity even though this study is limited to the acute treatment. No pathological indicators were observed in the hemogram and urinalysis. Overall, the treatment did not cause any significant pathological changes. Preclinical in vivo evaluation of magnetic extraction of small rest fragments in porcine kidneys presents a promising, atraumatic approach for fragments removal. It demonstrated safety, tolerance, and feasibility that warrants clinical investigation. This method has the potential to increase stone-clearance rates with shorter extraction times, offering a possibility for addressing the challenge of urolithiasis in clinical practice.

Knowledge‑map Analysis of Ureteroscopy for Urolithiasis

The utilization of ureteroscopy (URS) for managing urolithiasis has garnered substantial global recognition. Nonetheless, bibliometric analyses focusing on URS in the context of urolithiasis treatment remain sparse. Therefore, we used bibliometrics to summarize the relevant literature in this field in recent years, in order to grasp the core research directions, capture the developmental frontiers, and provide valuable information for urologists to understand the research hotspots. In this study, we compiled the literature on URS and urinary stones from the Web of Science core database over the past two decades. In this study, we compiled literature about URS and urolithiasis from the Web of Science Core Collection spanning the past two decades. The assembled data were subsequently visualized and analyzed using CiteSpace and VOSviewer software. The findings revealed a total of 1,461 publications, with a consistent annual increase and a notable surge post-2010. The most frequently occurring keywords identified were "ureteroscopy" and "calculi". Olivier Traxer, a prominent figure from France, is recognized as a leading expert in the domain, particularly emphasizing the practical application of diverse techniques for the treatment and management of urinary stones. The Journal of Urology has disseminated the most pertinent literature in this area, with Turkey emerging as the most prolific contributor. Keyword analysis within this field has identified four primary research hotspots: the investigation of complications to mitigate treatment risks, the standardization of treatment protocols, the determination of treatment indications based on stone types, and the implementation of novel techniques in ureteroscopic lithotripsy.

Does coiling of the proximal end of the ureteral stent affect stent-related symptoms?

OBJECTIVE

To evaluate the impact of coiling of the proximal end of the ureteral stent on stent-related symptoms (SRS) in in subgroup of patients undergoing preoperative ureteral stenting preceding flexible retrograde intrarenal surgery (RIRS).

MATERIALS AND METHODS

We performed a prospective comparative study including patients undergoing stent placement 7-10 days prior to RIRS. Patients were divided into 2 groups; in Group 1 coiling of proximal end of the DJ was present, while in Group 2 coiling was absent. Bladder pain, flank pain, hematuria, urgency, frequency, nocturia, and urge incontinence were evaluated on the day of surgery using Visual Analog Score (VAS).

RESULTS

In total, 81 patients, 45 males (55.6%) and 36 (44.4%) females were included. Patients in Group 2 had statistically significant severe representation of flank (43.2% vs. 22.7%, p-value = 0.049) and bladder pain compared to Group 1 (48.4% vs. 25.0%, p-value = 0.027). Additionally, they required analgesic medications more frequently (64.9% vs. 34.1%, p-value = 0.006), and experienced significantly more pronounced frequency (p-value = 0.012) and urgency (2.7 vs. 2.1, p-value = 0.033) compared to Group 1. Patients in group 1 recovered from their symptoms more frequently (52.3% vs. 29.7%, p-value = 0.041), occurring on day 4 and 5 following ureteral stenting.

CONCLUSION

Coiling of the proximal end of the DJ stent impacts stent-related symptoms significantly. Better outcomes of post-procedural frequency, urgency, bladder and flank pain were observed in patients in whom coiling was achieved. Moreover, those patients reported faster recovery from SRSs.

Safety and effectiveness of preoperative stenting compared to non-stenting in ureteroscopy for urinary stone disease: a meta-analysis of comparative studies

PURPOSE

Ureteroscopy (URS) is considered one of the first-line surgical treatments for urinary stones < 2 cm. Preoperative stenting (PS) employment in URS for urolithiasis remains debated, with evidence differing in terms of outcomes and recommendations. We sought to evaluate the influence of PS on surgical outcomes compared to non-PS (NPS) in patients with renal and ureteral stones undergoing ureteroscopic lithotripsy.

METHODS

Databases were searched until December 2023 for randomized and non-randomized studies reporting perioperative outcomes for PS and NPS. Pooled data were analyzed through a Random-Effects model when Higgins I2% heterogeneity values were > 50%; otherwise, a Fixed-Effects model was employed. Results were reported as risk ratios (RR), or mean differences (MD) with 95% confidence intervals (CI). Statistical significance was set at p < 0.05.

RESULTS

The analysis included 23,668 patients from 25 included studies (5 non-randomized prospective and 20 retrospective studies). Higher stone-free rates (SFR) were observed in kidney and ureteral stones (RR 1.05; 95%CI 1.03-1.08; p ≤ 0.0001), especially if managed with flexible URS (RR 1.05; 95%CI 1.01-1.09) in the PS cohort. Additionally, lower rates of intraoperative (RR 0.70; 95%CI 0.49-0.99; p = 0.04) and postoperative complications (RR 0.82; 95%CI 0.70-0.95; p = 0.008) were seen with PS. Both groups had a comparable operative time, length of stay (LOS), ureteral access sheath (UAS) placement success, and SFR in semi-rigid URS.

CONCLUSION

Higher SFR with PS were seen in kidney and ureteral stones, especially if f-URS was employed. Moreover, perioperative complications did not increase with PS. Future randomized studies, evaluating cost-effectiveness and quality of life are needed.

Acknowledging acute kidney disease following ureteroscopy and laser lithotripsy: results from a tertiary care referral center

BACKGROUND

Acute kidney disease (AKD) is a recently described syndrome consisting of kidney function abnormalities lasting less than 3 months. Little is known regarding AKD following ureteroscopy (URS) and laser lithotripsy.

OBJECTIVE

To evaluate the occurrence and evolution of AKD in stone patients treated with URS.

MATERIALS AND METHODS

Data from 284 patients treated with URS for urinary stones were retrospectively analyzed. According to the KDIGO 2020 criteria, AKD was defined as postoperative acute kidney injury (AKI) occurrence, estimated glomerular filtration rate (eGFR) decrease ≥ 35%, or serum creatinine (SCr) increase ≥ 50%. AKI was defined as SCr increase ≥ 0.3 mg/dL or ≥ 50%. AKD evolution was evaluated 60 days post-URS. Data were analyzed using descriptive statistics. Univariable (UVA) and multivariable (MVA) logistic regression analyses tested the association of patients' characteristics and perioperative data with the occurrence of AKD.

RESULTS

Overall, postoperative AKD occurred in 32 (11.3%) patients. Recovery from AKD was found in 26 (82%) patients and persistent AKD occurred in 6 (18%) patients. At UVA, age at surgery (p = 0.05), baseline SCr (p = 0.02), baseline CKD category (p = 0.006), Charlson comorbidity index (p = 0.01), operative time (p = 0.04) and postoperative complications (< 0.001) were associated with AKD. At MVA, CKD category (OR 2.99, 95% CI = 1.4-6.3; p = 0.004), operative time (OR 1.01, 95% CI = 1.001-1.018; p = 0.023) and postoperative complications (OR 3.5, 95% CI = 1.46-8.49; p = 0.005) were independent predictors of AKD.

CONCLUSIONS

AKD is a frequent complication in patients treated with URS. Moreover, AKD persists in a non-neglectable percentage of patients at medium-term follow-up. Therefore, nephrological assessment should be considered, especially in high-risk patients. Current findings should be considered for the peri-operative management of stone patients.

Complications of Single-Use Flexible Ureteroscopy vs. Reusable Flexible Ureteroscopy: A Narrative Review

Urolithiasis, or kidney stones, is a painful condition that is becoming increasingly common worldwide. For many, the solution lies in a minimally invasive procedure called flexible ureteroscopy (fURS). This technique involves inserting a tiny, flexible scope into the urinary tract to break up and remove stones. Reusable fURS scopes have traditionally been the norm. However, concerns about infection control and instrument durability have led to the development of single-use scopes. While both methods offer effective treatment, the question remains: which one is safer and more efficient? To answer this, we conducted a comprehensive review of the available research. We analyzed 37 studies that compared single-use and reusable fURS complication rates. While both methods carry risks, such as bleeding, infection, and ureteral injury, the overall complication rates were found to be similar. As technology continues to advance, fURS is becoming even safer and more effective. However, there is still a need for standardized reporting and further research to better understand the potential risks and benefits of both single-use and reusable scopes. Ultimately, the choice between the two will depend on various factors, including patient factors, surgeon preference, and healthcare resource availability.

Comparison of two negative pressure ureteral access sheaths combined with day-case flexible ureteroscopy for renal stones randomized trial

To compare the safety and effectiveness of the combination of intelligent intrarenal pressure control platforms and flexible end ureteral access sheath combined with flexible ureteroscopic lithotripsy (FURL) for the treatment of renal stones less than 2 cm with day case mode. From November 2023 to July 2024, a prospective, randomized, double-blind, parallel-controlled study was conducted to recruit 60 patients with upper urinary tract calculi measuring ≤ 2 cm in longest diameter. A total of 60 eligible patients were consecutively enrolled. Based on a pre-generated random number table and allocation scheme using SPSS 27.0, patients were assigned to either the intelligent pressure control group (IFURL, n = 30) or the head bending group (BFURL, n = 30). Blinding measures were implemented for patients, data collectors, statisticians, and analysts, with the allocation results disclosed to the surgeons prior to the start of the procedure in the operating room. The operation duration for IFURL and BFURL was 52.50 (48.00, 60.00) vs. 46.00 (36.00, 56.25), respectively (p = 0.047). Stone free rate (SFR) on the first postoperative day was 73.33% vs. 93.33% for IFURL and BFURL, respectively (p = 0.038). While, SFR was no significant difference between the two groups after two months(90.00% vs. 96.67%, p = 0.301). One patient in IFURL was readmitted after discharge due to fever 2 days post-discharge, and improved after 2 days of anti-infection treatment. One patient in BFURL was readmitted due to lumbar and abdominal pain from urine extravasation, which improved after 3 days of anti-infection treatment. SFR of one-month post-surgery for renal calculi ≤ 2 cm treated with intelligent pressure control and flexible UAS combined with FURL in day surgery mode was similar, with low infection-related complications and rehospitalization rates, showing no statistical difference. However, the overall hospitalization costs for the BFURL was lower than IFURL.

Fumarate hydratase-deficient renal cell carcinoma complicated with liver metastasis: case report

Background

Fumarate hydratase-deficient renal cell carcinoma (FH-RCC) is a rare subtype of kidney tumor. Most of them are solitary lesions, making preoperative diagnosis difficult, aggressive, and with poor prognosis. They may metastasize even at an early stage, however, there is currently no optimal diagnostic and therapeutic approach for metastatic FH-RCC.

Methods

We report the case of a 34-year-old male patient with renal tumor and liver metastasis, who underwent open tumor resection of the right kidney combined with resection of liver metastases. Postoperative pathology was confirmed, followed by targeted therapy.

Results

Postoperative pathological results confirmed FH-RCC, targeted therapy was performed after surgery. No tumor recurrence was observed during the follow-up of almost 16 months.

Conclusion

FH-RCC patients with liver metastasis can achieve a good prognosis through early resection of primary tumor and metastatic lesions combined with targeted therapy.

Optimal deflection techniques for flexible and navigable suction ureteral access sheaths (FANS): a comparative in vitro PEARLS analysis

PURPOSE

Flexible and navigable suction ureteral access sheaths (FANS) have been introduced without current evidence on how to optimize deflection. Aim was to evaluate in vitro deflection angles with 2 different FANS techniques-sheath advancement and ureteroscope deflection; and effects of sheath size-ureteroscope combinations.

METHODS

We evaluated in vitro deflection angles of 10/12Fr, 11/13Fr and 12/14Fr FANS (Hunan Reborn Medical Co. Ltd) with six single-use flexible ureteroscopes (Pusen Uscope 7.5Fr, OTU WiScope 7.5Fr, OTU WiScope 8.6Fr, Innovex EU-scope 8.7Fr, Red Pine RP-U-C12 8.7Fr and Boston Scientific Lithovue 9.5Fr). Two deflection techniques were tested: (1) sheath advancement-advancing the sheath forward over a maximally deflected ureteroscope, and (2) ureteroscope deflection-maximally deflecting the ureteroscope from various starting positions relative to tip of the sheath.

RESULTS

Intra and inter-scope comparisons of maximum deflection angles were significantly different (all ANOVA p < 0.01). Largest maximum angles for all ureteroscopes were with the sheath advancement technique (range 218°-277°), and second largest for most scopes using the ureteroscope deflection technique at tip (range 111°-212°), mostly deviating from manufacturer specifications (range 270°-275°). 10/12Fr and 11/13Fr sheath sizes were more flexible than 12/14Fr. Largest angles were with 11/13Fr sheath-OTU8.6Fr/Innovex8.7Fr combinations.

CONCLUSION

Optimal deflection with FANS is achieved using either a sheath advancement technique, or ureteroscope deflection technique at tip. Despite using these optimized techniques, deflection angles specified by manufacturers seem hardly achievable. The sheath advancement technique and 11/13Fr sheath-OTU8.6Fr/Innovex8.7Fr combinations may be better suited for lower pole situations. Urologists should be aware of these differences and apply the findings to their FANS technique.

First clinical evaluation of a flexible digital ureteroscope with direct in scope suctioning system (Pusen DISS 7.5Ch): prospective multicentric feasibility study

PURPOSE

A new digital single-use flexible ureteroscope, Pusen direct in scope suction (DISS) 7.5Fr (PU3033AH), was evaluated with respect to manoeuvrability, suction quality, visibility and clinical efficiency.

METHODS

A prospective cohort study was conducted in six tertiary reference centers in Europe and Asia between February-April 2024. Adult patients who underwent flexible ureteroscopy and laser lithotripsy (fURSL) for urolithiasis were included. Demographic, intraoperative and follow-up characteristics were recorded. Quality parameters were rated by each surgeon using a Likert scale.

RESULTS

a total of 57 fURSL were performed. Preoperative characteristics revealed a mean stone volume of 480.00mm3 (mean Hounsfield Unit- 998). 57.9%(n = 33) of the patients were pre-stented, and a ureteric access sheath was used in 64.9%(n = 37). Integrated-suction was deemed helpful in 94.7%(n = 54) fURSL as reported by the operators. An initial stone free rate (SFR) confirmed by postoperative imaging was achieved in 84.21%(n = 48). Quality parameters of the scope reached a mean Likert score of 4.5, with a "very good" mean evaluation for "scope placement", "visual quality", "irrigation", "deflection", "manoeuvrability", and "weight". "Suction quality" and "overall performance satisfaction" were rated "good". Comparing the Pusen DISS scope with other previously used scopes, overall satisfaction was rated 4.1. When asked if the surgeons would be willing to use the Pusen DISS 7.5Fr scope in the future, all the six surgeons answered positively.

CONCLUSION

The DISS 7.5 Pusen ureteroscope displayed good visibility, manoeuvrability and suction quality, with excellent operative results. Further evaluation with larger comparative cohorts will help understand the potential of in-vivo use of integrated suctioning systems for fURSL.

Analysis of postoperative infection factors of retrograde intrarenal surgery combined with negative pressure equipment for renal stones

Our study aimed to retrospectively analyze the patients who underwent the combination of negative pressure equipment and RIRS(NP-RIRS) for renal stones, and identified new high-risk factors related to infection. 456 patients with renal stones ≤ 3 cm underwent NP-RIRS in our department, from January 2022 to October 2023. All patients were divided into non-infection group(NIRIRS group) and infection group(IRIRS group) based on infection complications during the perioperative period. Establish a receiver operating characteristic curve(ROC curve)based on variables with statistical differences, and use the Jordan index to find the optimal cutoff value. Classify the data into two categories based on the best truncation value, and perform binary logistic regression analysis on the classified data. In the IRIRS group, there were 10 cases of fever (2.92%), 2 cases of sepsis (0.58%), and no cases of septic shock or death. The length and the CT value of the stone were 16 (13,21) vs. 22 (19,24) (p < 0.001), 764 (570,1012) vs. 1372 (841,1527) (p < 0.001), respectively, and there was a statistical difference. The surgical time of NIRIRS group and IRIRS group were 57 (50,65) vs. 75 (60,98), respectively (p < 0.001), with statistical differences. On the contrary, the stone-free rate(SFR) at 3 months after surgery was 97.60% vs. 91.70% (p = 0.209), and there was no difference. The length of stones, surgical time, and CT values of stones between the two groups were further used to establish ROC, with ROC areas of 0.791, 0.791, and 0.816, respectively(Fig. 2). Based on the Jordan index, the optimal cutoff values were 17.5 mm (stone size), 64.5 min (surgery time), and 732.5 HU (stone CT value), respectively. Three continuous variables were transformed into binary data using the best truncation criterion, and the classified results were subjected to binary logistic regression analysis. The results showed that the three variables remained independent risk factors for postoperative infection complications. The incidence of infection after NPRIRS was lower than TRIRS for kidney stones. Length of stones, surgical time, and CT value of stones were independent risk factors for postoperative infection in NPRIRS treatment of kidney stones. Due to the small sample size, the credibility and generalizability of the conclusions were limited.

Urosepsis after ureterorenoscopy, intraoperative recognition of type-IV stones could change clinical practice

OBJECTIVES

Urosepsis currently accounts for half of all post flexible ureterorenoscopy (F-URS) complications, with an incidence of up to 4.3%. It represents a quarter of all septic episodes in adults and 2% of hospital spendings. The primary objective of this study was to define the predictive clinical parameters that increase the risk of urosepsis after F-URS.

SUBJECTS/PATIENTS (OR MATERIALS) AND METHODS

This prospective multicentric study evaluated patients who underwent F-URS for calculus between June 2016 and June 2018 in eleven French centers. Clinical, bacteriological, morpho-constitutional stone data, intraoperative information and complications were compared. Risk factors for postoperative urosepsis were identified and analyzed.

RESULTS

We included 486 F-URS in 432 patients. The ureter was prepared using a double J stent in 51% of cases, a digital endoscope was used in 56% of patients with a median operative time of 120 min IQR (90-125) and using a sheath in 90% of cases. Postoperative urosepsis was observed in 18 patients (4%) with a median time to onset of 2 days IQR (1-5). The presence of coronary insufficiency: 3 (17%) vs 14 (3%) p = 0.005, a larger stone diameter: 11 cm [9-17] vs 10 cm [8-13] p = 0.02, a positive preoperative urine culture even when treated: 3 (17%) vs 56 (12%) p = 0.04, as well as the final composition of the type IV calculus (carbapatite or struvite) 5 (28%) vs 20 (4%) p < 0.001, were significantly associated with the occurrence of urosepsis. In multivariate analysis, only the presence of a type IV stone (OR = 14.0; p = 0.025) remained significant.

CONCLUSION

Ureteroscopic treatment of a type IV stone (carbapatite or struvite) in a patient should raise concerns about the risk of post-operative urosepsis. When recognized intraoperatively, they should lead to a pyelic urinary sample and prolonged clinical surveillance.

Steady-state versus burst lasing techniques for thulium fiber laser

OBJECTIVE

To evaluate the stone ablation rate and direct thermal damage from thulium fiber laser (TFL) lithotripsy using continuous (C) and burst (B) lasing techniques on an in vitro ureteral model.

METHODS

The TFL Drive (Coloplast, Humlebaek, Denmark) was used in an in vitro saline-submerged ureteral model. Ten participants, including five junior and five experienced urologists, conducted the experimental setup with 7 different settings comparing two lasing techniques: steady-state lasing (0.5 J/10 Hz = 5W for 300 s and 0.5 J/20 Hz = 10W for 150 s) and burst, intermittent 5 s on/off lasing (0.5 J/20 Hz, 0.5 J/30 Hz, 0.5 J/60 Hz, 0.1 J/200 Hz, and 0.05 J/400 Hz) with a target cumulative energy of 1500 J using cubic 125 mm3 phantom BegoStonesTM. Ureteral damage was graded 1-3 based on the severity of burns and holes observed on the surface of the ureteral model.

RESULTS

The were no significant differences in stone ablation mass neither between C and B lasing techniques, nor between expertise levels. At C lasing technique had only mild ureteral lesions with no significant differences between expertise levels (p: 0.97) or laser settings (p: 0.71). At B lasing technique, different types of thermal lesions were found with no expertise (p: 0.11) or setting (p: 0.83) differences. However, B laser setting had higher grade direct thermal lesions than C (p: 0.048).

CONCLUSION

Regarding efficacy, C and B lasing techniques achieve comparable stone ablation rates. Safety-wise, B lasing mode showed higher grade of direct thermal lesions. These results should be further investigated to verify which of the lasing mode is the safest in vivo. Until then and unless proven otherwise, a C mode with low frequency should be recommended to avoid ureteral wall lesions.

The impact of siphoning effect on renal pelvis pressure during ureteroscopy using an in vitro kidney and ureter model

PURPOSE

To experimentally measure renal pelvis pressure (PRP) in an ureteroscopic model when applying a simple hydrodynamic principle, the siphoning effect.

METHODS

A 9.5Fr disposable ureteroscope was inserted into a silicone kidney-ureter model with its tip positioned at the renal pelvis. Irrigation was delivered through the ureteroscope at 100 cm above the renal pelvis. A Y-shaped adapter was fitted onto the model's renal pelvis port, accommodating a pressure sensor and a 4 Fr ureteral access catheter (UAC) through each limb. The drainage flowrate through the UAC tip was measured for 60 s each run. The distal tip of the UAC was placed at various heights below or above the center of the renal pelvis to create a siphoning effect. All trials were performed in triplicate for two lengths of 4Fr UACs: 100 cm and 70 cm (modified from 100 cm).

RESULTS

PRP was linearly dependent on the height difference from the center of the renal pelvis to the UAC tip for both tested UAC lengths. In our experimental setting, PRP can be reduced by 10 cmH20 simply by lowering the distal tip of a 4 Fr 70 cm UAC positioned alongside the ureteroscope by 19.7 cm. When using a 4 Fr 100 cm UAC, PRP can drop 10 cmH20 by lowering the distal tip of the UAC 23.3 cm below the level of the renal pelvis.

CONCLUSION

Implementing the siphoning effect for managing PRP during ureteroscopy could potentially enhance safety and effectiveness.

Using fosfomycin to prevent infection following ureterorenoscopy in response to shortage of cephalosporins: a retrospective preliminary study

BACKGROUND

In 2019, the shortage of cefazolin led to the demand for cefotiam and cefmetazole exceeding the supply. The Department of Nephro-urology at Nagoya City University Hospital used fosfomycin as a substitute for perioperative prophylaxis. This retrospective preliminary study evaluated the efficacy of fosfomycin and cefotiam for preventing infections following ureterorenoscopy.

METHODS

The study included 182 patients who underwent ureterorenoscopy between January 2018 and March 2021). Perioperative antibacterial treatment with fosfomycin (n = 108) or cefotiam (n = 74) was administered. We performed propensity score matching in both groups for age, sex, preoperative urinary catheter use, and preoperative antibiotic treatment.

RESULTS

The fosfomycin and cefotiam groups (n = 69 per group) exhibited no significant differences in terms of patients' median age, operative duration, preoperative urine white blood cell count, preoperative urine bacterial count, and the rate of preoperative antibiotic treatment. In the fosfomycin and cefotiam groups, the median duration of postoperative hospital stay was 3 and 4 days, respectively; the median maximum postoperative temperature was 37.3 °C and 37.2 °C, respectively. The fosfomycin group had lower postoperative C-reactive protein levels and white blood cell count than the cefotiam group. However, the frequency of fever > 38 °C requiring additional antibiotic administration was similar.

CONCLUSIONS

During cefotiam shortage, fosfomycin administration enabled surgeons to continue performing ureterorenoscopies without increasing the complication rate.

Success rate and complications of performing elective ureteroscopy in <1 week versus over 1 week from renal colic initiation in ureteral stones larger than 6 mm

Background

The aim of this study was to compare the outcomes, success rate, and complications of performing elective ureteroscopy at different times: <1 week from renal colic initiation (early) and more than 1 week from renal colic initiation (late) in patients with ureteral stone larger than 6 mm.

Materials and Methods

This comparative observational study was conducted on 338 consecutive patients. Patients were evaluated in two groups: patients who underwent ureteroscopy in <1 week (A) and patients who underwent ureteroscopy in more than 1 week (B) from renal colic initiation. Helical unenhanced computed tomography was used to assess the size, location, and hardness of stone for all patients. Operation success was defined as complete clearance of stone with no stone residue (stone free) at 2-week postoperative ultrasonography with no need to further interventions. Operation data were collected using medical records, and postoperative complications were investigated at 2 weeks postoperative follow-up visits.

Results

Group A included 165 patients and Group B included 173 patients. The overall mean stone size was 8.60 ± 1.12 mm: for Group A 9.13 ± 0.94 mm and for Group B 8.10 ± 1.04 mm (P < 0.001). Stone residues were found in 11 patients: 9 in Group A (5.4%) and 2 in Group B (1.1%) (P = 0.026). Nine patients needed repeated ureteroscopy: 8 (4.8%) in Group A and 1 (0.6%) in Group B (P = 0.015). A double-J stent was used for 85 (51.5%) patients in Group A and 66 (38.2%) patients in Group B (P = 0.016). Major intraoperative complications did not happen in any patients. Fifty-three (32.1%) patients in Group A and 28 (16.2%) patients in Group B suffered from postoperative complications (P = 0.001).

Conclusion

Our study revealed that performing elective ureteroscopy with an interval of more than 1 week from the onset of renal colic in combination with medical treatments was associated with less need for double-J stent placement, less need for repeated ureteroscopy, and fewer postoperative complications compared to performing elective ureteroscopy in <1 week from the renal colic onset in nonemergent patients with ureteral stone larger than 6 mm. Although the rate of ureteroscopy failure was higher among the patients who underwent ureteroscopy in <1 week from their renal colic initiation, there was no statistically significant relationship between performing ureteroscopy in <1 week and an increased risk for ureteroscopy failure.

Japanese survey of perioperative complications and ureteral stricture after ureteroscopy with laser lithotripsy for upper urinary tract stones in multicenter collaborative study

OBJECTIVES

This study aimed to investigate perioperative complications and the details of postoperative ureteral stricture after ureteroscopy with laser lithotripsy (URS-L) for upper urinary tract stones in Japan.

METHODS

Patient data on intra- and postoperative complications after ureteroscopy using URS-L were retrospectively collected from multiple centers in Japan between April 2017 and March 2020 with the cooperation of the Japanese Society of Endourology and Robotics. Data included the number of patients undergoing URS-L, number and type of intra- and postoperative complications, and detailed characteristics of postoperative ureteral stricture.

RESULTS

In total, 14 125 patients underwent URS-L over 3 years at 82 institutions. Annual URS-L numbers gradually increased from 4419 in 2017, to 4760 in 2018, and 4946 in 2019. The total complication rate was 10.5%, which was divided into intra-operative complications in 1.40% and postoperative complications in 9.18%. The annual incidences of intra- and postoperative complications were not significantly different from year to year (p = 0.314 and p = 0.112). Ureteral perforation, ureteral avulsion, and the intra-operative conversion rate were 1.35%, 0.03%, and 0.02%, respectively. Fever >38°C, septic shock, blood transfusion, and postoperative mortality were 7.44%, 0.81%, 0.07%, and 0.04%, respectively. Ureteral stricture occurred in 0.8% of cases. The median length of stricture site was 10.0 mm and the success rate of stricture treatment was 54.6%.

CONCLUSION

Although URS-L utilization has increased in Japan, the annual complication rate has remained steady. Although URS-L is a useful and less invasive procedure, devastating complications can still occur.

Comparative study of thulium fiber laser versus holmium:yttrium-aluminum-garnet laser for ureteric stone management with semi-rigid ureteroscopy: A prospective, single-center study

Objective

To compare the efficacy and safety of thulium fiber laser (TFL) and holmium:yttrium-aluminum-garnet (Ho:YAG) laser for ureteric stone management with semi-rigid ureteroscopy.

Methods

In a prospective study from January 2020 to December 2021, we compared 40 patients in each group who underwent semi-rigid ureteroscopic lithotripsy with TFL and that with Ho:YAG laser. Stone volume, stone density, stone fragmentation rates, total lasing time, total operative time, endoscopic vision, retropulsion and stone free rates were analyzed in both groups and compared.

Results

Mean stone volume was comparable in the TFL group and the Ho:YAG laser group (282.45 [standard deviation, SD 139.79] mm3 vs. 279.49 [SD 312.52] mm3; p=0.964). Mean stone density was also comparable in the TFL group and the Ho:YAG laser group (1135.30 [SD 317.04] Hounsfield unit vs. 1131.75 [SD 283.03] Hounsfield unit; p=0.959). The mean stone fragmentation rates calculated as stone volume divided by lasing time were 25.85 (SD 10.61) mm3/min and 21.37 (SD 14.13) mm3/min in the TFL group and the Ho:YAG laser group, respectively (p=0.113). The mean total lasing time (10.15 [SD] 4.69 min vs. 11.43 [SD 4.56] min; p=0.222), mean operative time (25.13 [SD 9.51] min vs. 25.54 [SD 10.32] min; p=0.866), and mean total hospital stay (2.62 [SD 0.77] days vs. 2.61 [SD 0.84] days; p=0.893) were comparable in the TFL group and in the Ho:YAG group. The vision was better and retropulsion was less in the TFL group. The stone-free rate at 1 month postoperatively was slightly better in the TFL group (100% vs. 90%; p=0.095).

Conclusion

TFL technology was associated with the comparable total surgical time, total lasing time, and stone fragmentation rate with Ho:YAG laser. However, TFL had better endoscopic vision, lesser stone retropulsion, and slightly better stone-free rates.

Ureteral access sheaths in RIRS: a retrospective, comparative, single-center study

OBJECTIVES

To evaluate the use of ureteral access sheaths (UAS) in reducing operative time and complications, as well as improving stone-free rates (SFR), while assessing their overall safety and efficiency.

METHODS

Data regarding 234 patients who underwent retrograde intrarenal surgery (RIRS) for stones up to 3 cm between January 2017 and March 2020 were retrospectively analyzed. About 52.5 % of procedures were performed utilizing a UAS. Differences in operative time, fluoroscopy time, stone-free rate, and complications were analyzed between procedures with and without UAS and stratified, according to stone burden size, into three groups (Group A: 0.5-1 cm; Group B: 1-2 cm; Group C: 2-3 cm).

RESULTS

Operative time, fluoroscopy time, and residual fragments size were lower in RIRS without UAS, respectively, 54.27 ± 24.02 vs. 62.23 ± 22.66 min (p=0.010), 2.72 ± 0.89 vs. 4.44 ± 1.67 min (p<0.0001), and 3.85 ± 0.813 vs. 4.60 ± 0.83 mm (p=0.011). Considering stone burden, operative time was lower in RIRS without UAS for Group A (36.40 ± 8.555 vs. 46.05 ± 6.332 min) (p<0.0001) while higher for Group B (60.39 ± 18.785 vs. 50.14 ± 5.812 min) (p=0.002). Similarly, fluoroscopy time was lower in RIRS without UAS in every group, respectively, 2.11 ± 0.34 vs. 2.74 ± 0.57 min (p<0.0001), 2.94 ± 0.51 vs. 4.72 ± 0.37 min (p<0.0001), and 3.78 ± 1.26 vs. 6.79 ± 1.17 min (p<0.0001). Only Group C had a statistically significant difference in residual fragment size without UAS (3.89 ± 0.782 vs. 4.75 ± 0.886 mm) (p=0.050).

CONCLUSIONS

UAS should be carefully evaluated considering the increased fluoroscopy time and the differences in operative time related to different stone burdens.

Recent advances in the treatment of renal stones using flexible ureteroscopys

Upper urinary tract stones are a common urological disease that can be treated by flexible ureteroscopy (FURS) through the natural urinary tract, in addition to extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy. The advantages of FURS are less trauma, faster recovery, and fewer complications, while its disadvantages include poor results of lithotripsy and stone extraction when dealing with larger stones, and prolonged operation time. Over the last two decades, the emergence of new technologies such as FURS combined with negative pressure suction, robot-assisted FURS, and artificially intelligent FURS, coupled with improvements in laser technology (the use of thulium fiber lasers and the invention of single-use flexible ureteroscopes (su-fURS) suitable for primary level application, have significantly increased the global adoption of FURS. This surge in usage holds a promising future in clinical application, benefiting a growing number of patients with renal calculi. Accompanied by changes in technical concepts and therapeutic modalities, the scope of indications for FURS is broadening, positioning it as a potential primary choice for urolithiasis treatment in the future. This review outlines the progress in employing FURS for the treatment of renal calculi in order to generate insights for further research.

Sedation vs. general anesthesia in stone ureteroscopy: Comparison of efficacy and safety, a post COVID-19 report

INTRODUCTION

Ureterorenoscopy (URS) for ureteral or renal stones is traditionally performed under general anesthesia (GA). Sedation is an alternative to GA, allowing control of the level of consciousness, spontaneous ventilation, and faster recovery. Our aim was to compare sedation and GA for patients undergoing ureterorenoscopy. Endpoints were stone-free rate (SFR) and complication rates.

METHOD

Monocentric comparative retrospective study including all consecutive ureterorenoscopies for ureteral or renal stone. The inclusion period was dichotomized in two 6-months periods due to the COVID-19 pandemic: from January 1 to July 1, 2019 (URS under GA) and from January 1 to July 1, 2021 (URS under GA or sedation). Stone-free (SF) status was defined as the absence of stone or fragment>4mm after the first ureterorenoscopy. Complication rates were assessed according to the Satava (perioperative complications) and Clavien-Dindo (postoperative complications) classifications. Statistical analysis was performed by Chi-square test.

RESULTS

A total of 185 patients were included for a total of 206 ureterorenoscopies; 82 underwent ureterorenoscopy under GA and 103 under sedation. The median stone size was 10 [7-16] mm. In all, 150 (81%) patients had at least one intrarenal stone. The SFR was similar between the two groups (67% GA group, 69% sedation group, P=0.912). In the sedation group, the mean SFR in ureter was 83.7% vs. 92.5% in the GA group. In renal cavities, the mean SFR was 46.4% in the sedation group vs. 42.5% in the GA group. Satava grade I, IIa, and IIb complications were 5 (6%), 5 (6%), and 1 (1%) in the GA group and 6 (6%), 1 (1%), and 3 (3%) in the sedation group, respectively (P=0.214). The grade I, II, III, and IV Clavien complications were 6 (7%), 3 (4%), 0 (0%), and 2 (2%) in the GA group and 6 (6%), 4 (4%), 1 (1%), and 4 (4%) in the sedation group, respectively (P=0.928).

CONCLUSION

Our post COVID-19 study showed no difference in efficacy and safety between ureterorenoscopy under sedation and GA for patients with renal stones. Our results confirm the interest of the sedation procedure, particularly in the context of outpatient surgery.

LEVEL OF EVIDENCE: 4

Clinical Efficacy Evaluation of a Novel Negative Pressure Ureteroscopic Lithotripsy for Ureteral Stones

OBJECTIVE

To evaluate the clinical efficacy of a novel negative pressure ureteroscopic lithotripsy (NP-URL) compared to standard ureteroscopic lithotripsy (S-URL) for treating ureteral stones.

METHODS

A total of 284 patients diagnosed with ureteral stones and who underwent ureteroscopic lithotripsy between December 2020 and May 2022 at our hospital were included in the study. Among them, 146 cases underwent NP-URL and 138 cases underwent S-URL. The negative pressure device used in NP-URL consists of a 5F ureteric catheter and a tee joint. We evaluated the operative duration, stone-free rate, incidence of postoperative complications, stone retropulsion rate, and adjunct procedure rate between the two groups.

RESULTS

The mean operative duration was significantly shorter in the NP-URL group compared to the S-URL group (30.17 ± 5.84 minutes vs 34.84 ± 6.62 minutes; P＜.05). Additionally, the NP-URL group had a lower incidence of postoperative fever (1.4% vs 8.7%; P＜.05), reduced stone retropulsion rate (3.4% vs 11.6%; P＜.05), and a statistically lower rate of adjunct procedures (5.5% vs 14.5%, P＜.05). The NP-URL group also demonstrated a higher primary stone-free rate (91.8% vs 81.9%; P＜.05). However, there was no significant difference in the final stone-free rate between the NP-URL and S-URL groups (P＞.05).

CONCLUSION

NP-URL potentially reduces operative duration, significantly decreases the incidence of postoperative complications, and achieves better primary stone-free rates compared to S-URL.

Risk factors of early infectious complications after ureterorenoscopy for stone disease: a prospective study

PURPOSE

To prospectively evaluate the rate and associated risk factors of early infectious complications after ureterorenoscopy for urolithiasis.

METHODS

After ethical committee approval, 400 therapeutic retrograde ureterorenoscopy procedures between August 3, 2020 and November 24, 2021 were included for analysis in a single-center study. Postoperative infection was defined as an afebrile urinary tract infection, fever (≥ 38 °C) with pyuria (≥ 300 WBC/μL) or proven urinary pathogen, and urosepsis. The primary outcome was the rate of infectious complications after ureterorenoscopy. Secondary outcomes were the perioperative factors that increased the risk of infectious complications within 30 days of surgery using univariate and multivariate logistic regression analysis.

RESULTS

Twenty-nine of four hundred (7.3%) patients developed an infectious complication within 30 days after ureterorenoscopy. Ten (2.5%) patients developed an afebrile urinary tract infection, eight (2.0%) developed fever with pyuria, five (1.3%) febrile urinary tract infection, and six (1.5%) urosepsis. On univariate analysis, preoperative stent-type JFil® pigtail suture stent was significantly associated with the dependent variable (p < 0.001). On multivariate logistic regression analysis, older age (OR 1.035; 95% CI 1.006-1.070; p = 0.02) was found to be significantly associated with developing a postoperative infectious complication.

CONCLUSIONS

A 7.3% rate of postoperative infectious complications and 1.5% urosepsis rate were observed after therapeutic ureterorenoscopy, without the need of intensive care admission. The only significant risk factors were preoperative stent type (JFil® pigtail suture stent) on univariate analysis, and older age on multivariate logistic regression analysis. Further multicentric prospective observational data are needed in this field.

The association between renal pelvis urine density and the risk of severe infectious complications in patient with symptom-free hydronephrosis after shock wave lithotripsy: a multi-center prospective study

Finding reliable and easy-to-obtain predictors of severe infectious complications after shock wave lithotripsy (SWL) is a major clinical need, particular in symptom-free hydronephrosis. Therefore, we aim to prospectively investigate the predictive value of Hounsfield units (HU) in renal pelvis urine for the risk of severe infectious complications in patients with ureteral stones and symptom-free hydronephrosis after SWL. This multi-center prospective study was conducted from June 2020 to December 2023. The HU of renal pelvis urine was measured by non-enhanced computed tomography. The severe infectious complications included systemic inflammatory response syndrome, sepsis, and septic shock. Binary logistic regression models assessed the odds ratios (ORs) and 95% confidence intervals (CIs). Finally, 1,436 patients with ureteral stones were enrolled in this study. 8.9% (128/1,436) of patients experienced severe infectious complications after SWL treatment. After adjusting confounding variables, compared with the patients in the lowest renal pelvis urine density quartile, the OR (95% CI) for the highest quartile was 32.36 (13.32, 78.60). There was a positive linear association between the HU value of renal pelvis urine and the risk of severe infectious complications after SWL (P for trend < 0.001). Furthermore, this association was also observed stratified by age, gender, BMI, stone size, stone location and hydronephrosis grade (all P for interaction > 0.05). Additionally, the nonlinear association employed by restricted cubic splines is not statistically significant (nonlinear P = 0.256). The AUROC and 95%CI of renal pelvis urine density were 0.895 (0.862 to 0.927, P value < 0.001). The cut-off value was 12.0 HU with 78.59% sensitivity and 85.94% specificity. This multi-center prospective study demonstrated a positive linear association between HU in renal pelvis urine and the risk of severe infectious complications in patients with ureteral stones and symptom-free hydronephrosis after SWL, regardless of age, gender, BMI, stone size, stone location, and hydronephrosis grade. These findings might be helpful in the SWL treatment decision-making process.