In vitro comparison of simulated intrapelvic pressure in an artificial kidney model during retrograde intrarenal surgery among various single-use ureteroscopes.

OBJECTIVES: This study compares intrapelvic pressure (IPP) during retrograde intrarenal surgery with various single-use flexible ureteroscopes (f-URS) in an artificial kidney model. METHODS: We created an artificial kidney model with a pressure sensor using a bladder evacuation device. The model was completely closed and the only backflow was on the side of the ureteroscope inside the ureteral access sheath (UAS). We tested five single-use f-URSs (LithoVue, Wiscope, PU3022A, PU3033A, and AXIS) with six different types of UAS (9.5/11.5-14/16 Fr). Using the automatic irrigation system, 30 s of irrigation was performed at various pressures (40-180 mmHg) and steady-state IPP was recorded. IPP was compared between the five single-use f-URSs. IPP cutoff value was determined at 30 mmHg. The diameter of the endoscope tip and the curved and shaft parts were also measured and recorded. RESULTS: The diameters of all parts were significantly different between single-use f-URSs. The maximum IPP tended to be higher in ureteroscopes with larger diameters of the proximal parts (curved part/shaft part). In LithoVue and Uscope PU3022A f-URSs, the maximum IPP did not exceed 30 mmHg when UAS ≥12/14 Fr was used. In AXIS and Wiscope f-URSs, it did not exceed the cutoff value when the UAS ≥11/13 Fr was used. In Uscope PU3033A f-URS, it did not exceed 30 mmHg when the UAS ≥10/12 Fr was used. CONCLUSIONS: Maximum IPP tended to be higher in f-URSs with larger diameters of the proximal part and the appropriate size of the UAS differed between various single-use f-URSs.

Predictive risk factors of urinary tract infection following flexible ureteroscopy despite preoperative precautions to avoid infectious complications.

PURPOSE: Urinary tract infection (UTI) is a common complication after flexible ureteroscopy (fURS) despite technical precautions to avoid infectious complications. The aim was to investigate incidence and predictive risk factors of UTI following fURS procedure. PATIENTS AND METHODS: We conducted a retrospective study including consecutive fURS performed in our center from January 2015 to March 2019. The indications were: nephrolithiasis management and diagnosis and conservative treatment of upper urinary tract urothelial carcinomas (UTUC). Since 2015, we had technical precautions to avoid postoperative infectious complications: centralized collection of preoperative urine cultures which are examined daily by an urologist and a service provider, systematic use of ureteral access sheath and application of standardized antibiotic prophylaxis measures. The primary endpoint was occurrence of UTI within 15 days following fURS. RESULTS: Six hundred and four fURS were included for nephrolithiasis (n = 462) and UTUC management (n = 142). The median (IQR) age in the study cohort was 61(48-68) years, 268 female patients were included (44.4%), the median (IQR) Charlson score was 2(1-4) and single-use fURS were used in 186 cases (30.8%). Postoperative UTI occurred in 41 cases (6.7%). In multivariate analysis, female gender (OR 2.20 [1.02-5.02], p = 0.04), UTI within the last 6 months (OR 2.34 [1.12-5.11], p = 0.02), preoperative polymicrobial urine culture (OR 4.53 [1.99-10.56], p < 0.001) and increased operative time (OR 1.02 [1.002-1.031], p = 0.02) remain associated with postoperative UTI. CONCLUSIONS: In a large cohort study, female gender, prior UTI, increased operative time and preoperative polymicrobial urine culture were associated with the occurrence of postoperative UTI. Limiting operative time and improving our knowledge of polymicrobial urine cultures could reduce the infectious risk.

Initial Experience and Clinical Assessment of the Karl Storz FLEX-XC1 Single-Use Flexible Ureteroscope.

INTRODUCTION: The Karl Storz FLEX-XC1 is a novel single-use flexible ureteroscope that uses the same videographics platform as its reusable digital counterpart. We evaluated the technical performance of the FLEX-XC1 in its initial clinical use. METHODS: We reviewed a series of consecutive ureteroscopy procedures performed by 2 endourologists using the FLEX-XC1 for indications for which we typically use a single-use device: total stone burden > 15 mm or > 10 mm in the lower pole, anticipated case duration > 60 minutes, bilateral procedure, or upper tract urothelial cancer procedures. We assessed device tip deflection, intraoperative mechanical failure, and clinical outcomes for each case. Surgeons rated visual clarity, image quality, and maneuverability on a 1 to 5 Likert scale. RESULTS: Of 29 procedures using FLEX-XC1, 27 (93%) were successfully completed. Preoperative upward deflection was < 270° in 6 (21%) cases, and downward deflection was < 270° in 9 (31%) cases. Three types of intraoperative malfunctions occurred: rotational twisting of deflectable tip (4 cases, 13%), device not advancing through distal ureter (1 case, 3%), and working channel not accommodating a 365-µm laser (1 case, 3%). Visual clarity, image quality, and maneuverability were rated as 5 "very good" or 4 "good" in 100%, 100%, and 97% of cases, respectively. No device-specific or general 30-day complications were observed. CONCLUSIONS: The FLEX-XC1 showed comparable image quality and maneuverability to reusable digital devices. We observed incomplete deflection in up to 31% of cases and mechanical failure in 2 cases. The FLEX-XC1 may be advantageous in prolonged cases where maintaining visual clarity is paramount.

Comparing outcomes of single-use vs reusable ureteroscopes: a systematic review and meta analysis.

Flexible ureterolithotripsy is a frequent urological procedure, usually used to remove stones from the kidney and upper ureter. Reusable uretero-scopes were the standard tool for that procedure, but recent concerns related to sterility and maintenance and repair costs created the opportunity to develop new technologies. In 2016, the first single-use digital flexible ureteroscope was introduced. Since then, other single-use ureteroscopes were developed, and studies compared them with the reusable ureteroscopes with conflicting results. The purpose of this study is to describe the literature that compares the performance of single-use and reusable flexible ureteroscopes in retrograde intrarenal surgery for urinary stones. A Systematic Review was performed in October 2022 in accordance with the Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA). A search in MEDLINE, EMBASE, Web of Science, Google Scholar and LILACS retrieved 10,039 articles. After screening, 12 articles were selected for the Meta-Analysis. No differences were found in stone-free rate (OR 1.31, CI 95% [0.88, 1.97]), operative time (MD 0.12, CI 95% [-5.52, 5.76]), incidence of post-operative fever (OR 0.64, CI 95% [0.22, 1.89]), or incidence of post-operative urinary tract infection (OR 0.63 CI 95% [0.30, 1.32]). No differences were observed in the studied variables. Hence, the device choice should rely on the availability, cost analysis and surgeons' preference.

First worldwide report on safety and efficacy of using small 7.5 Fr scope for pediatric ureteroscopy: prospective pilot series from Europe.

Introduction: Although pediatric urolithiasis remains relatively uncommon, its global prevalence is on the rise. Technological advances have led to miniaturization of instruments especially in the form of single use scopes. As the evidence on the use of small single use ureteroscopes in children is scarce, we have conducted a pilot two-center study to analyze the outcomes of pediatric patients treated with the Pusen 7.5 Fr single use scopes at our institutions. Material and methods: This study included consecutive pediatric patients with urinary stones treated with the small Pusen 7.5 Fr single use ureteroscope. The study was conducted at two large European tertiary endourology centers that specialize in pediatric kidney stone management. Patient data and outcomes were prospectively collected, and analysis was performed regarding patient demographics, stone parameters, as well as stone free rate (SFR), operating time, and complications. Results: In this pilot study, 26 patients were included with a median age of 12 years (7.0-16.0) and a male to female ratio of 14:12. The mean cumulative stone size was 15.15 mm (SD ±11.1) and multiple stones were present in 9 (34.6%) patients. Pre-operative stent, access sheath and post-operative stent usage was done in 12 (46.2%), 23 (88.5%) and 13 (50%) patients respectively. The median operative time was 47 minutes (IQR: 40.0-63.8). Following the initial procedure 24 (92.3%) patients were stone free, while no intra or postoperative complications were observed. Conclusions: Our study demonstrates that the use of the small 7.5 single use ureteroscope is safe and efficient for the treatment of urinary stones in pediatric patients with high stone-free rates and no complications noted in our series. While this might become a standard of care in future, to confirm and validate our findings further studies with larger cohorts are warranted.

Comparison of single-use flexible ureteroscopes with a reusable ureteroscope for the management of paediatric urolithiasis.

INTRODUCTION: To compare the efficacy, side effects, and cost-effectiveness between a single-use digital flexible ureteroscope and a reusable flexible ureteroscope in the treatment of paediatric renal stones. METHODS: This analytic, case-control, monocentric study included all patients undergoing flexible ureterosopies for stone treatment. Between April 2016 and February 2019, a reusable (Flex-XC®, Karl Storz) flexible ureteroscope was used (control group), whereas a single-use (Uscope®, PUSEN Medical©) flexible ureteroscope was used in all procedures from March 2019 to April 2021. Clinical and procedural outcomes, operative times, complication rates, hospital stay, and costs per procedure were evaluated. RESULTS: Forty-three cases using a reusable flexible ureteroscope and thirty-nine using a single-use flexible ureteroscope were included in the study. Demographic patient characteristics, stone burden, location and composition, preoperative presence of a double-J stent, procedural outcomes, mean length of postoperative hospital stay, and complications (4.6% versus 5%, p = 0.81) were comparable between the two groups. Median operative duration for stone removal was 93 min (20-170) with reusable versus 81 min (55-107) with the single-use scope (p = 0.18). Scope failure occurred four times with the reusable scope and in no case with the single-use. The total cost per procedure associated with the use of single-use scopes (798 Euros) was lower than a reusable scope (1483.23 Euros). DISCUSSION: Single-use flexible ureteroscopes were created to bypass the problems incurred when reusable scopes were damaged and therefore not available for use in surgical procedures. Single-use flexible ureteroscopes are always immediately available and ready to be used, even in urgent cases, as they typically do not require maintenance or sterilization. Compared with their reusable counterparts, single-use flexible ureteroscopes have similar digital performance (270°), image quality and we found no difference in the success and complication rates. Cost analysis of a reusable flexible ureteroscope must consider the purchase price, maintenance and repair costs, and decontamination costs (including handling, detergent, bacterial culture, transportation, and storage costs). In contrast, only purchase price is included in cost analysis for single-use flexible ureteroscopes. Our study suggests that single-use flexible ureteroscopes may be associated with lower costs per procedure than their reusable counterparts. CONCLUSION: Single-use flexible ureteroscopes are an interesting alternative to their reusable counterparts, particularly in terms of material resource management. Cost analyses conducted using a low volume of cases representative of a paediatric urology division favour the use of single-use ureteroscopes.

Single-Use Ureteroscopes Are Associated with Decreased Risk of Urinary Tract Infection After Ureteroscopy for Urolithiasis Compared to Reusable Ureteroscopes.

Objective: Urinary tract infection (UTI) is a common complication after ureteroscopy. Despite sterilization, there is evidence that reusable ureteroscopes can still harbor bacteria. Whether this property is associated with increased risk of UTI is unknown. The objective of this study was to compare rates of postoperative UTI after ureteroscopy for urolithiasis performed with single-use ureteroscopes vs reusable ureteroscopes. Materials and Methods: This was a single-center, retrospective cohort study of all patients who underwent ureteroscopy for urolithiasis between June 2012 and March 2021. Outcomes were compared between those who underwent stone removal with single-use and reusable ureteroscopes. The primary endpoint was postoperative UTI. The secondary endpoints were intra-operative and postoperative outcomes, and health service utilization after surgery. Results: Of 991 patients identified, 500 (50.4%) underwent ureteroscopy with a single-use ureteroscope. Rates of postoperative UTI were lower in those undergoing ureteroscopic stone removal with a single-use ureteroscope compared to a reusable ureteroscope (6.5% vs 11.9%, p = 0.018). In multivariable analysis, use of a single-use ureteroscope was associated with lower odds of postoperative UTI compared to a reusable ureteroscope when adjusting for risk (odds ratio 0.37, p = 0.015). Use of a single-use ureteroscope was associated with a higher stone clearance rate compared to a reusable ureteroscope (90.0% vs 83.9%, p = 0.005). There was no difference in operative time, overall complication rate, readmission, or emergency department visits between two groups. Conclusion: Single-use ureteroscopes are associated with a twofold decreased risk of UTI and increased stone clearance rate after ureteroscopy for urolithiasis compared to reusable ureteroscopes.

Stone removing efficiency and safety comparison between single use ureteroscope and reusable ureteroscope: a systematic review and meta-analysis.

BACKGROUND: Urologists are gradually beginning to use single-use ureteroscopes (sufURSs), despite a lack of high-level evidence as to their efficacy and safety. This systematic review was registered on PROSPERO (no. CRD42020181808). METHODS: The PubMed, Embase, Web of Science, and Cochrane Library databases were searched for studies published before October 1, 2020. Jadad score tools were used to evaluate the quality of the included randomized controlled trials (RCTs) and the Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the included nonrandomized studies. Two researchers independently extracted data according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) principles. A data synthesis was performed using Stata 15.0. Heterogeneity was mainly evaluated with I2 tests. In addition to funnel plots, Egger's and Begg's tests were used to detect publication bias. A sensitivity analysis was also performed. Stone-free rates and postoperative complications were the 2 primary outcomes; operation-time data were also extracted. RESULTS: Six studies (comprising 887 patients) containing the efficacy data and 5 studies (comprising 952 patients) containing the safety data that were finally included in the quantitative analysis. In relation to stone removal, no significant difference was found in terms of efficacy [Mantel-Haenszel statistic (M-H), relative risk (RR): 1.01, 95% confidence interval (CI): 0.96-1.07, P=0.658) or safety (M-H, RR: 1.30, 95% CI: 0.96-1.75, P=0.093) between the sufURS and the reusable flexible ureteroscope (rfURS), and no significant heterogeneity was found. A publication bias was detected in the efficacy comparison; however, the trim-and-fill analysis indicated that the original synthesis results remained stable. CONCLUSIONS: In relation to stone removal, sufURSs were found to be comparable to rfURS, and no compromising complications were found. However, the results should be treated with caution due to limitations related to the small number of studies included in the analysis.

Benchtop Assessment of a New Single-Use Flexible Ureteroscope.

Introduction: Single-use flexible ureteroscopes are an increasingly popular alternative to reusable ureteroscopes. In this study, we performed a benchtop examination of the physical and optical properties of the new Dornier Axis™ (Webling, Germany) single-use ureteroscope. Methods: Ten new, never-used Dornier Axis ureteroscopes were assessed for optical performance, maximal tip deflection, and irrigation flow rate with an empty working channel and with insertion of 200 and 365 µm laser fibers, and a 1.9F nitinol basket. All ureteroscopes were then fully deflected 100 times in each direction, and maximal deflection angles were re-measured with and without instruments in the working channel. All measurements were performed in duplicate. In vitro optical testing for resolution, image distortion, and depth of field was performed and compared vs the LithoVue™ (Boston Scientific, Marlborough, MA) single-use ureteroscope. Statistical analyses using paired Wilcoxon rank-sum tests and Kruskal-Wallis multiple-group comparison tests were performed in R. Results: Median maximal deflection angles exceeded 300° in both directions before and after 100 full deflection cycles for all groups except the 365 µm laser fiber group. After 100 deflection cycles, there was no change in the majority of working instruments, except a decrease in upward flexion with an empty channel and 200 µm Moses™ laser fiber, and downward flexion with 200 µm Flexiva™ laser fiber (all <10°). After excluding the 365 µm fiber, there was no difference in multi-group comparison for upward and downward flexion pre- and post-cycling. Median flow rate through an empty channel was 48.0 mL/min, and it decreased significantly with all used instruments (p < 0.001). Compared with the LithoVue, the Axis demonstrated superior resolution at all tested distances and less distortion. Conclusions: The new Dornier Axis single-use ureteroscope demonstrates excellent tip deflection, which remains unchanged after 100 manual flexions in each direction. The Axis also demonstrates superior optical performance compared with the LithoVue in benchtop testing.

Comparative medico-economic study of reusable vs. single-use flexible ureteroscopes.

PURPOSE: Reusable flexible-ureteroscopes (fURS) require personnel and budget for processing and repairing, whereas single-use fURS were recently developed. After exclusive reusable fURS since 2011, we experienced high repair costs and single-use fURS were therefore introduced in mid-2017. We aimed to evaluate economic and practical advantages and disadvantages of reusable versus single-use fURS. MATERIALS AND METHODS: First, we evaluated the incidence of breakage and repairs of reusable fURS in 2017. We assessed the overall operational costs of reusable fURS including purchase, processing, and repairing in our institution from 2011 to 2017. Following our experience, we created a model to compare operation costs/procedure of single-use fURS with reusable fURS depending on repair costs. RESULTS: In 2017, repair costs of reusable fURS increased by 345% compared with the period 2011-2016, causing: a median unavailability per reusable fURS of 200 days/year (100-249), median number of functioning fURS 0/5-3/5 per operating day, while unavailability of reusable fURS had become the first reason for cancellation of procedure. Since it was introduced, single-use fURS accounted for 59% of the flexible ureteroscopy activity. Taking into account the costs of processing, maintenance and repair, in 2011-2016 versus 2017, the single-use fURS was cost-effective compared with the reusable fURS until the 22nd procedure versus the 73rd procedure, respectively. CONCLUSIONS: After years of exclusive reusable fURS, the rising incidence of breakage not only increased maintenance costs but also hampered daily activity owing to unavailability of the devices. The introduction of single-use with reusable fURS provided substantial help to maintain our activity.

The application of a single-use fiberoptic flexible ureteroscope for the management of upper urinary calculi.

OBJECTIVE: To evaluate the clinical outcomes with a Chinese single-use fiberoptic flexible ureteroscope (YouCare Tech) from a prospective database. MATERIALS AND METHODS: A prospective study was conducted in a single center in China between January 2016 and October 2017. All consecutive patients who underwent flexible ureteroscopy performed by YouCare flexible ureteroscope were analyzed. Patients' demographics, clinical characteristics, intraoperative parameters, postoperative complications, and stone-free rate were evaluated and recorded. Stone-free status was defined as no visible stones or clinically insignificant residual stones < 2 mm on a postoperative image study. RESULTS: A total of 684 procedures were performed for 653 patients (31 patients had bilateral stones). A double J stent had been previously placed in 431 patients. The location of the calculi was upper calyx, middle calyx, lower calyx, and renal pelvis and proximal ureter in 74, 101, 211, 115, and 183 patients, respectively. The median operative time was 52 min. The postoperative stone-free rate for the first 2 weeks after surgery was 78.5%, which increased to 91.1% at the first month. The overall stone-free rate was 95.2%. The complication rate was minor and short-term, such as gross hematuria or flank pain. CONCLUSION: YouCare flexible ureteroscope can be considered effective and safe in the treatment of both upper ureteral and renal stones in selected patients. Further evaluation of comparison with other FURS's surgical outcomes and cost-effectiveness analysis will help to present the best utility of this single-use FURS in clinical practice.

First clinical evaluation of the new single-use flexible and semirigid Pusen ureteroscopes.

INTRODUCTION: The purpose of the present study was to clinically evaluate two new single-use Pusen ureteroscopes, one semirigid with a flexible tip (srURS) and one flexible (fURS). MATERIALS AND METHODS: During ten consecutive procedures (five srURS and five fURS), we subjectively evaluated on a scale from 0 (poor) to 10 (excellent), the scope's deflection, image quality, and maneuverability prior to, during and after the surgery. Patient demographics, complications with the devices, and troubleshooting were recorded. RESULTS: There were a total of ten patients, five of which were female while the other five were male. Mean age was 58.9 years. Seven patients had a single kidney stone with mean size of 9.6 mm (1.6-20 mm). Half of the patients were pre-stented. For the fURS, the preoperative image quality rating was 8.4 (8-10), compared with 6.8 (4-9) during surgery. The preoperative deflection rating was 9.6+ 0.9 (8-10), while during surgery this decreased to 8.0 (6-10) and to 6.0 (4-8) when using a laser fiber. The srURS had a preoperative image quality rating of 9.2 (8-10), which decreased to 7.6 (6-9) while using the scope. The deflection rating decreased from 9.4 (7-10) preoperatively to 7.0 (1-10) postoperatively, and a similar reduction was observed in the maneuverability rating, from 9.6 (8-10) to 7.4 (1-10). Ureteroscopy was considered as a standard in four of the fURS and three of the srURS procedures. The mean overall satisfaction rating was 6. CONCLUSIONS: The two new single-use ureteroscopes, one flexible and one semirigid, were considered to have allowed standard ureteroscopy in four and three out of the five procedures for each scope, respectively. The image quality, deflection, and maneuverability ratings decreased during the procedure for both scopes.

Performance of Single-Use FlexorVue vs Reusable BoaVision Ureteroscope for Visualization of Calices and Stone Extraction in an Artificial Kidney Model.

PURPOSE: To evaluate and compare Flexor®Vue™, a semidisposable endoscopic deflection system with disposable ureteral sheath and reusable visualization source, and a nondisposable fiber optic ureteroscope in a standard in vitro setting. MATERIALS AND METHODS: FlexorVue and a reusable fiber optic flexible ureteroscope were each tested in an artificial kidney model. The experimental setup included the visualization of colored pearls and the extraction of calculi with two different extraction devices (NCircle® and NGage®). The procedures were performed by six experienced surgeons. Visualization time, access to calices, successful stone retraction, and time required were recorded. In addition, the surgeons' workload and subjective performance were determined according to the National Aeronautics and Space Administration-task load index (NASA-TLX). We referred to the Likert scale to assess maneuverability, handling, and image quality. RESULTS: Nearly all calices (99%) were correctly identified using the reusable scope, indicating full kidney access, whereas 74% of the calices were visualized using FlexorVue, of which 81% were correctly identified. Access to the lower poles of the kidney model was significantly less likely with the disposable device, and time to completion was significantly longer (755 s vs 153 s, p < 0.001). The stone clearance success rate with the disposable device was 23% using the NGage and 13% using the NCircle basket. Overall NASA-TLX scores were significantly higher using FlexorVue. The conventional reusable device also demonstrated superior maneuverability, handling, and image quality. CONCLUSIONS: FlexorVue offers a semidisposable deflecting endoscopic system allowing basic ureteroscopic and cystoscopic procedures. For its use as an addition or replacement for current reusable scopes, it requires substantial technical improvements.