Single-Use Flexible Ureteroscopes: How Do They Compare with Reusable Ureteroscopes?

Development and Validation of a Preoperative Nomogram for Endoscopic Management Decision Making in Upper Urinary Tract Urothelial Carcinoma

OBJECTIVE

We aimed to develop and validate a preoperative nomogram that predicts low-grade, non-muscle invasive upper urinary tract urothelial carcinoma (LG-NMI UTUC), thereby aiding in the accurate selection of endoscopic management (EM) candidates.

METHODS

This was a retrospective study that included 454 patients who underwent radical surgery (Cohort 1 and Cohort 2), and 26 patients who received EM (Cohort 3). Utilizing a multivariate logistic regression model, a nomogram predicting LG-NMI UTUC was developed based on data from Cohort 1. The nomogram's accuracy was compared with conventional European Association of Urology (EAU) and National Comprehensive Cancer Network (NCCN) models. External validation was performed using Cohort 2 data, and the nomogram's prognostic value was evaluated via disease progression metrics in Cohort 3.

RESULTS

In Cohort 1, multivariate analyses highlighted the absence of invasive disease on imaging (odds ratio [OR] 7.04; p = 0.011), absence of hydronephrosis (OR 2.06; p = 0.027), papillary architecture (OR 24.9; p < 0.001), and lack of high-grade urine cytology (OR 0.22; p < 0.001) as independent predictive factors for LG-NMI disease. The nomogram outperformed the two conventional models in predictive accuracy (0.869 vs. 0.759-0.821) and exhibited a higher net benefit in decision curve analysis. The model's clinical efficacy was corroborated in Cohort 2. Moreover, the nomogram stratified disease progression-free survival rates in Cohort 3.

CONCLUSION

Our nomogram ( https://kmur.shinyapps.io/UTUC_URS/ ) accurately predicts LG-NMI UTUC, thereby identifying suitable candidates for EM. Additionally, the model serves as a useful tool for prognostic stratification in patients undergoing EM.

Retrospective study of single-use digital flexible ureteroscopic lithotripsy versus miniaturized percutaneous nephrolithotomy for 1.5-2.5cm lower pole renal stones

PURPOSE

Retrospective analysis was performed on the clinical information of patients with 1.5-2.5 cm lower pole renal stones treated by single-use digital flexible ureteroscopic lithotripsy (fURS) and miniaturized percutaneous nephrolithotomy (MPCNL) in affiliated hospital of the Nantong University from January 2020 to December 2022. To compare the safety and efficacy of single-use fURS and MPCNL in the treatment from 1.5cm to 2.5cm lower pole renal stones.

METHODS

Clinical information of 141 patients were collected and divided into single-use fURS group and MPCNL group according to their treatment methods, including 83 patients in the single-use fURS group and 58 patients in the MPCNL group. Baseline data, data on the clinical characteristics of stones, laboratory examination data, operation time, and postoperative data of the two groups were collected. Statistical analysis was made on the collected data to analyze the differences and causes between the two groups of patients.

RESULTS

There was no significant difference in the baseline data and preoperative clinical features of 141 patients between the two groups (P > 0.05). In comparison of postoperative serum indexes, the drop values of hemoglobin and creatinine in single-use fURS group were lower than those in MPCNL group, and the difference was statistically significant (P < 0.05). The stone free rate was higher in the MPCNL group than in the single-use fURS group on the first day after surgery. At the 1st month after surgery, the two groups were similar. At 3rd month after surgery, the single-use fURS group was slightly higher than the MPCNL group, with no statistical significance (P > 0.05). The total complication rate in single-use fURS group was slightly lower than that in MPCNL group, but there was no statistical significance (P > 0.05).

CONCLUSIONS

Single-use fURS has similar safety and efficacy to MPCNL in the treatment of 1.5-2.5cm lower pole renal stones. Single-use fURS may be a new option for the treatment of these stones.

Single use flexible ureteroscopes: Current status and future directions

Introduction

Single use ureteroscopes are a technological innovation that have become available in the past decade and gained increased popularity. To this end, there are now an increasing number of both benchside and clinical studies reporting outcomes associated with their use. Our aim was to deliver a narrative review in order to provide an overview of this new technology.

Methods

A narrative review was performed to gain overview of the history of the technology's development, equipment specifications and to highlight potential advantages and disadvantages.

Results

Findings from preclinical studies highlight potenial advantages in terms of the design of single use ureteroscopes such as the lower weight and more recent modifications such as pressure control. However, concerns regarding plastic waste and environmental impact still remain unanswered. Clinical studies reveal them to have a non inferior status for outcomes such as stone free rate. However, the volume of evidence, especially in terms of randomised trials remains limited. From a cost perspective, study conclusions are still conflicting and centres are recommended to perform their own micro cost analyses.

Conclusions

Most clinical outcomes for single use ureteroscopes currently match those achieved by reusable ureteroscopes but the data pool is still limited. Areas of continued debate include their environmental impact and cost efficiency.

Reuse and Reprocessing of Endoscopic Instruments: For

Reusable endoscopes appear to be most environmentally sustainable when the carbon footprint of routine device maintenance is optimized. Single-use endoscopes may offer cost-savings in clinical settings that accelerate device damage, such as prolonged procedure time or complex patient anatomy. For many urology practices, a hybrid approach that integrates single-use and reusable devices may be most economically sensible and environmentally sound.

Flexible ureteroscopy for lower pole calculus: is it still a challenge?

PURPOSE

Flexible ureteroscopy (fURS) is steadily gaining popularity in the management of renal calculi, including those located in the lower pole (LP). Due to difficulty in accessing to the LP of kidney in minority of cases with fURS and reports of lower stone-free rate (SFR), it is still considered as a challenge in selected cases. The purpose of the review was to analyze the various aspects of fURS for LP stones.

METHODS

An extensive review of the recent literature was done including different factors such as anatomy, preoperative stenting, stone size, flexible scopes, types of lasers, laser fibers, suction, relocation, stone-free rates, and complications.

RESULTS

The significance of various lower pole anatomical measurements remain a subject of debate and requires standardization. Recent improvements in fURS such as single-use digital scopes with better vision and flexibility, high power laser, thulium fiber laser, smaller laser fiber, and accessories have significantly contributed to make flexible ureteroscopy  more effective and safer in the management of LP stone. The utilization of thulium fiber lasers in conjunction with various suction devices is being recognized and can significantly improve SFR.

CONCLUSIONS

With the significant advancement of various aspects of fURS, this treatment modality has shown remarkable efficacy and gaining widespread acceptance in management of LP kidney stones. These developments have made the fURS of LP stones less challenging.

Reprocessing semicritical items: An overview and an update on the shift from HLD to sterilization for endoscopes

BACKGROUND

Semicritical medical devices are defined as items that come into contact with mucous membranes or nonintact skin (e.g., gastrointestinal endoscopes, endocavitary probes). Such medical devices require minimally high-level disinfection.

METHODS

Analyze the methods used to reprocess semicritical medical devices and identify methods and new technologies to reduce the risk of infection.

RESULTS

The reprocessing methods for semicritical medical devices is described as well as a shift from high-level disinfection to sterilization for lumened endoscopes.

CONCLUSIONS

Strict adherence to current guidelines and transition to sterilization for endoscopes is required as more outbreaks have been linked to inadequately disinfected endoscopes and other semicritical items than any other reusable medical devices.

TAVAC: choledochoscopy disposable scopes, and the single-stage vs. two-stage approach to choledocholithiasis

BACKGROUND

Previous studies have been published evaluating the benefits and drawbacks of clearing the common bile duct of stones using a single-stage approach (LCBDE + LC) versus a two-stage approach (ERCP followed by LC). These studies have demonstrated that a single-stage approach offers similar outcomes and morbidities as a two-stage approach, with the added benefit of a lower cost and shorter length of stays. However, it is significant we understand why LCBDE is not commonly performed currently and also the lapse in surgical trainee exposure and competence in LCBDE. This paper aims to address the lapse in surgical trainee exposure to LCBDE, evaluate the scopes currently available to perform LCBDE, and review current data evaluating the risks and benefits of single-stage versus two-stage approaches to.

METHODS

We utilized PubMed to analyze all publications related to the various disposable scopes utilized to perform choledochoscopy. We also discuss the need for disposable scopes and how this new market niche is transforming the choledochoscopy space.

RESULTS

We analyzed the data related to single-stage and two-stage approach to choledocholithiasis. We noted an overall shorter length of stay and also decreased costs in favor of a single-stage approach.

CONCLUSION

A single-stage LCBDE is the most cost-effective treatment option for choledocholithiasis in patients with choledocholithiasis undergoing a cholecystectomy. In addition, single-stage approach is associated with shorter length of stay. Knowledge of the available choledochoscopes and tools available to surgeons to perform choledochoscopy is significant. The evidence does support the use of disposable choledochoscope from a cost and cross-contamination perspective. Additionally, efforts should be made to incorporate LCBDE into the teaching paradigm of surgical training programs.

Learning from the past and present to change the future: Endoscopic management of upper urinary tract urothelial carcinoma

Current guidelines recommend endoscopic management (EM) for patients with low-risk upper urinary tract urothelial carcinoma, as well as those with an imperative indication. However, regardless of the tumor risk, radical nephroureterectomy is still mainly performed worldwide despite the benefits of EM, such as renal function maintenance, no hemodialysis requirement, and treatment cost reduction. This might be explained by the association of EM with a high risk of local recurrence and progression. Furthermore, the need for rigorous patient selection and close surveillance following EM may be relevant. Nevertheless, recent developments in diagnostic modalities, pathological evaluation, surgical devices and techniques, and intracavitary regimens have been reported, which may contribute to improved risk stratification and treatments with superior oncological outcomes. In this review, considering recent advances in endourology and oncology, we propose novel treatment strategies for optimal EM.

A single center comparative study of two single use digital flexible ureteroscopy in the management of renal stones less than 2 cm

PURPOSE

For renal stones < 2 cm, guidelines recommend the use of retrograde intrarenal surgery as a first line treatment option. Many available single use flexible ureteroscopy were found. We aim to compare the effectiveness of two single use flexible ureteroscopy; Pusen Uscope 3011 versus LithoVue in the management of renal stones less than 2 cm.

METHODS

Our study prospectively included 60 patients equally divided in to two groups: Pusen group and LithoVue group during the period from June 2020 to June 2021. The included patients were above 18 years old. Perioperative details as operative time, fluoroscopy time, hospital stay, and complications were recorded. Stone free rate was assessed. Base purchase cost was also compared.

RESULTS

There was no statistically significant difference between the two groups regarding age, gender, and body mass index (BMI), stones size, side, number and location. The perioperative evaluation and outcome had no statistically significant differences between the two groups regarding the operative time, hospital stay, access sheath use, and stone free rate or radiation exposure. Among all cases, we had 49 cases (81.6%) with no postoperative complications (21 cases for Pusen group and 28 cases for LithoVue group). The incidence of postoperative complications was significantly higher among Pusen group than LithoVue group (p = 0.02). Initial purchase cost for both FURS had no significant difference (P = 0.86).

CONCLUSION

RIRS can be performed effectively with Pusen 3011 and LithoVue single use flexible ureteroscopy in patients diagnosed with renal calculi < 2 cm with superior outcomes with LithoVue.

Unfavorable factors in accessing the pelvicalyceal system during retrograde flexible ureteroscopy (fURS)

Flexible ureteroscopy (fURS) is a well-established procedure for treating multiple upper-urinary tract pathologies, particularly renoureteral lithiasis. Endoscopes have undergone significant advancements, including miniaturization, improved optics, and increased maneuverability. In addition, advancements in accessory instruments, such as the performance of laser fibers, guidewires, and extraction probes, have played a significant role in improving the overall performance of flexible ureteroscopy procedures. However, despite these advancements, unique circumstances can make achieving optimum results during flexible ureteroscopy challenging. These include congenital renal anomalies (horseshoe kidneys, ectopic kidneys, rotation anomalies), as well as the unique intrarenal anatomy (infundibulopelvic angle, infundibular length) or the specifications of the endoscope in terms of maneuverability (active and passive deflection). This review explored challenging scenarios during flexible ureteroscopy procedures in the pyelocaliceal system.

Single-use versus conventional reusable flexible ureteroscopes - an evaluation of the functional parameters

The purpose of single-use flexible ureteroscopes (su-fURS) was to overcome the limitations of conventional reusable ureteroscopes in terms of maneuverability and maintenance. We aimed to perform a systematic literature review on available su-fURS performance versus conventional reusable fURS focusing on clinical data. A systematic research using Pubmed was performed evaluating single-use fURS and reusable fURS in urinary tract stone disease, including prospective assessments and case series. This review aimed to provide an overview of single-use and disposable flexible ureteroscopes and to examine and compare their capabilities (deflection, irrigation, optical properties). We included 11 studies, where the single-use fURS were compared to the reusable fURS. The studies with single-use ureteroscopes included data on LithoVue (Boston Scientific), The Uscope UE3022 (Pusen, Zhuhai, China), NeoFlex-Flexible, (Neoscope Inc San Jose, CA), 23 YC-FR-A (Shaogang). For reusable ureteroscopes, data were included on three models, two digital (Karl Storz Flex-XC and Olympus URF-Vo) and one fiber optic (Wolf-Cobra). There were no significant differences in stone-free rate, procedure duration, or functional capabilities between single-use fURS and reusable fURS. The systematic literature review analyzed operative time, functional capabilities, stone-free rates, and postoperative complications of the ureteroscopes, and a special chapter about renal abnormalities to emphasize that they are a good choice having a high proportion of stone-free rates and few risks, particularly in treating difficult-to-access calculi. Single-use fURS demonstrate a comparable efficacy with reusable fURS in resolving renal lithiasis. Further studies on clinical efficacy are needed to determine whether single-use fURS will reliably replace its reusable counterpart.

RIRS with disposable or reusable scopes: does it make a difference? Results from the multicenter FLEXOR study

Introduction

With several single-use ureteroscopes now available, our aim was to analyze and compare data obtained globally from high-volume centers using both disposable and reusable flexible ureteroscopes and see if indeed in real-world practice either scope has a distinct advantage.

Methods

Retrospective analysis was performed on the FLEXOR registry, which was created as a TOWER group (Team of Worldwide Endourological Researchers, research wing of the Endourological Society) endeavor. Patients who underwent retrograde intrarenal surgery (RIRS) for renal stones from January 2018 to August 2021 were enrolled from 20 centers globally. A total of 6663 patients whose data were available for analysis were divided into Group 1 (Reusable scopes, 4808 patients) versus Group 2 (Disposable scopes, 1855 patients).

Results

The age and gender distribution were similar in both groups. The mean stone size was 11.8 mm and 9.6 mm in Groups 2 and 1, respectively (p < 0.001). Group 2 had more patients with >2 cm stones, lower pole stones and of higher Hounsfield unit. Thulium fiber laser (TFL) was used more in Group 2 (p < 0.001). Patients in Group 2 had a slightly higher stone-free rate (SFR) (78.22%) and a lower number of residual fragments (RFs) compared with Group 1 (p < 0.001). The need for further treatments for RF and overall complications was comparable between groups. On multivariate analysis, overall complications were more likely to occur in elderly patients, larger stone size, lower pole stones, and were also more when using disposable scopes with longer operative time. RFs were significantly higher (p < 0.001) for lower pole, larger, harder, multiple stones and in elderly.

Conclusion

Our real-world practice observations suggest that urologists choose disposable scopes for bigger, lower pole, and harder stones, and it does indeed help in improving the single-stage SFR if used correctly, with the appropriate lasers and lasing techniques in expert hands.

An in vitro Comparative Assessment of Single-Use Flexible Ureteroscopes Using a Standardized Ureteroscopy Training Model

INTRODUCTION

Perceived benefits like decreased contamination rates and reduced postoperative incidence of complications after urolithiasis surgery have led to increased adoption of single-use flexible ureteroscopes (su-fURS). Using a validated, standardized simulator model with enhanced "fluoroscopic" capabilities, we performed an in vitro comparative assessment of four commercially available models of su-fURS. Both objective and subjective parameters were assessed in this study.

METHODS

Two standardized tasks, (1) exploration of the model's kidney collecting system and (2) repositioning of a stone fragment from the upper renal to lower renal pole were assigned to participants, who performed these tasks on all four scopes. Four models of su-fURS (Boston LithoVue, PUSEN PU3033A, REDPINE, INNOVEX EU-ScopeTM) were assessed, with task timings as end-points for objective analysis. Cumulative "fluoroscopic" time was also recorded as a novel feature of our enhanced model. Post-task questionnaires evaluating specific components of the scopes were distributed to document subjective ratings.

RESULTS

Both subjective and objective performances (except stone repositioning time) across all four su-fURS demonstrated significant differences. However, objective performance (task timings) did not reflect subjective scope ratings by the participants (Rs < 0.6). Upon Kruskal-Wallis H test with post hoc analyses, REDPINE and INNOVEX EU-ScopeTM were the preferred su-fURS as rated by the participants, with overall scope scores of 9.00/10 and 9.57/10.

CONCLUSIONS

Using a standardized in vitro simulation model with enhanced fluoroscopic capabilities, we demonstrated both objective and subjective differences between models of su-fURS. However, variations in perception of scope features (visibility, image quality, deflection, maneuverability, ease of stone retrieval) did not translate into actual technical performance. Eventually, the optimal choice of su-fURS fundamentally lies in individual surgeon preference, as well as cost-related factors.

Hybrid flexible ureteroscopy strategy in the management of renal stones - a narrative review

The introduction of single-use flexible ureteroscopes (suFURSs) in daily practice tends to overcome the main limitations of reusable ureteroscopes (reFURSs), in terms of high acquisition costs, maintenance, breakages and repairing costs, reprocessing and sterilization, as retrograde intrarenal surgery (RIRS) is promoted as first-line treatment of renal stones in most cases. A hybrid strategy implies having both instruments in the armamentarium of endourology and choosing the best strategy for cost-efficiency and protecting expensive reusable instruments in selected high-risk for breakage cases such as large stones of the inferior calyx, a steep infundibulopelvic angle or narrow infundibulum, or abnormal anatomy as in horseshoe and ectopic kidney. In terms of safety and efficiency, data present suFURSs as a safe alternative considering operating time, stone-free, and complication rates. An important aspect is highlighted by several authors about reusable instrument disinfection as various pathogens are still detected after proper sterilization. This comprehensive narrative review aims to analyze available data comparing suFURSs and reFURSs, considering economic, technical, and operative aspects of the two types of instruments, as well as the strategy of adopting a hybrid approach to selecting the most appropriate flexible ureteroscope in each case.

Clinical Evaluation of Single-Use, Fiber-Optic, and Digital Ureterorenoscopes in the Treatment of Kidney Stones

<b><i>Introduction:</i></b> Indication of ureteroscopy for the treatment of urolithiasis has expanded immensely over the last decade. Fiber-optic and digital reusable instruments present the standard in clinical practice, but various newly available single-use devices might offer an exciting alternative. To date, the evidence is limited to clinical evaluation and efficacy of single-use ureteroscopes (URS) compared to standard instruments. Therefore, we evaluate a single-use instrument’s clinical characteristics and efficacy in direct comparison with a fiber-optic and digital device. <b><i>Methods:</i></b> A prospective study was conducted for patients undergoing endoscopic therapy for urolithiasis at a tertiary care center. We evaluated the different instruments’ clinical performance in categories of visibility, the stability of visibility, irrigation flow, and surgeon’s satisfaction. Statistical analyses were performed by SPSS using the Chi-Quadrat and Kruskal-Wallis test. A <i>p</i> value of <i>p</i> ≤ 0.05 was defined as statistically significant. <b><i>Results:</i></b> A total number of 77 patients were included and distributed as follows: 35 (46.7%) single-use, 19 (25.3%) digital, and 23 (28%) fiber-optic URS. Patients’ characteristics were homogenous over the three cohorts in sex, stone amount, and localization. The stone-free rate was equal in all three cohorts (<i>p</i> = 0.31). We identify stability of visibility, irrigation flow, and satisfaction were equal in all cohorts (<i>p</i> = 0.73; <i>p</i> = 0.20; <i>p</i> = 0.20). We report a significant difference in visibility, with 100% rated excellent in the digital URS group (<i>p</i> = 0.028). <b><i>Discussion/Conclusions:</i></b> Single-use URS achieve comparable clinical outcomes with equal stone-free rates in direct comparison with fiber-optic and digital reusable instruments. Accordingly, single-use devices present an adequate alternative for endoscopic therapy of urolithiasis.

Single-Use Versus Reusable Endoscopes for Percutaneous Biliary Endoscopy with Lithotripsy: Technical Metrics, Clinical Outcomes, and Cost Comparison

PURPOSE

To compare procedure and fluoroscopy time, technical and clinical success, and costs between single-use and reusable endoscopes in patients undergoing percutaneous biliary endoscopy (PBE) with lithotripsy.

MATERIAL AND METHODS

In this retrospective study, we included 34 patients (67 procedures) treated with PBE for gallstone removal from October 24, 2014, through February 12, 2020, using reusable (28 procedures) or single-use (39 procedures) endoscopes. We compared 1) procedure time, 2) fluoroscopy time, 3) technical success rate (accessing the biliary system and locating the gallstone), 4) clinical success rate (at least partial gallstone removal), 5) complication rate, and 6) cost of use. Alpha = 0.05.

RESULTS

Mean (± standard deviation) procedure time was not significantly different between single-use (136 ± 45 minutes) and reusable endoscopes (136 ± 51 minutes) (p = 0.47). Mean fluoroscopy time was significantly shorter for single-use endoscopes (11 ± 8.4 minutes) than for reusable endoscopes (18 ± 12 minutes) (p = 0.01). When comparing single-use vs. reusable endoscopes, rates were not significantly different for technical success (N=37, 95% vs. N=26, 93%) or clinical success (N=35, 90% vs. N=21, 75%) (both, p>0.05). Only 1 complication was noted in the reusable endoscope group (p=0.42). Cost per case was lower for single-use ($1500) than for reusable ($3987) endoscope procedures, primarily due to differences in capital costs and costs due to repair.

CONCLUSION

Single-use endoscopes offer the potential for less radiation exposure to the patient and lower cost per case, which may reduce financial barriers to offering PBE in interventional radiology practices. Clinical and technical success rates did not differ by endoscope type.

The Life and Death of Percutaneous Stone Removal: "Looking Back-Looking Forward"

Although percutaneous nephrolithotomy (PCNL) is less morbid than open surgery, it still carries risks of significant complications as well as injury to the renal parenchyma. Flexible ureteroscopic stone removal, although causes no appreciable damage to the renal parenchyma, has limitations, most notably, a lower stone-free rate than PCNL. Advances in our knowledge regarding ureteral physiology combined with technical developments applied to ureteral access sheath deployment and size may well propel retrograde intrarenal surgery to the forefront of kidney stone removal, regardless of stone size or location.

Comparison of pre- and post-surgical images of reusable and single use flexible ureteroscopes: a qualitative analysis

Introduction

Given the fragility of reusable ureterorenoscopes, many single use instruments have appeared on the market. Unfortunately, reuse of these scopes occurs in undeveloped countries in order to cut costs. This raises safety concerns for the patient.

The aim of this article was to macroscopically evaluate the changes that single use flexible ureterorenoscopes (su-fURS) suffer after a retrograde intrarenal surgery (RIRS), and to compare them to reusable fURS.

Material and methods

Pre and post-operative images of the instruments used in 23 RIRS were obtained. All the cases had renal calculi of the inferior calix between 10–15 mm, and all of them were treated with Holmium laser. The ureterorenoscopes used were: Storz^® Flex X2, Storz^® Flex XC, Pusen^® 3022, OTU^® Wiscope, AnQIng^® Innovex and Boston Scientific^® LithoVue. Qualitative comparisons of these were made.

Results

After su-fURS usage, significant damage was observed, especially on the distal tip. Deflection was not compromised. Reusable fURS did not sustain any damage after their use.

Conclusions

fURS are delicate equipment, especially if they are of single use. The considerable damage sustained by single use scopes could mean that reuse of these instruments is dangerous and should be avoided.

Comparison Between Single-Use Flexible Ureteroscope and Reusable Flexible Ureteroscope for Upper Urinary Calculi: A Systematic Review and Meta-Analysis

Objective: This article explores the differences in the effectiveness and safety of the treatment of the upper urinary calculi between single-use flexible ureteroscope (su-fURS) and reusable flexible ureteroscope (ru-fURS).

Methods: We systematically searched PubMed, Embase, Cochrane Library, Scopus database, and CNKI databases within a period from the date of database establishment to November 2020. Stata 16 was used for calculation and statistical analyses.

Results: A total of 1,020 patients were included in the seven studies. The statistical differences were only found in the Clavien–Dindo grade II postoperative complication [odds ratio (OR) 0.47; 95% CI 0.23–0.98; p = 0.04]. No significant statistical differences were observed in operative time (OT), estimated blood loss (EBL), length of hospital stay (LOS), and stone-free rate (SFR).

Conclusion: Our meta-analysis results demonstrate that su-fURS, compared with ru-fURS, has similar effectiveness and better security for treating upper urinary calculi.

Single-use flexible ureteroscopes: update and perspective in developing countries. A narrative review

Flexible ureteroscopy is a well-established method for treatment of urinary stones but flexible ureteroscopes are expensive and fragile devices with a very limited lifetime. Since 2006 with the advent of digital flexible ureteroscopes a great evolution has occurred. The first single-use flexible ureteroscope was launched in 2011 and new models are coming to the market. The aim of this article is to review the characteristics of these devices, compare their results with the reusable devices and evaluate the cost-benefits of adopting single-use flexible ureteroscopes in developing countries.

How to evaluate a flexible ureterorenoscope? Systematic mapping of existing evaluation methods

Objectives

The objective of this study was to identify, map and review scope‐related and user‐related parameters used to evaluate the quality of flexible ureterorenoscopes. Thereby identifying key items and variability in grading systems.

Methods

A literature search of four databases (MEDLINE [Ovid], EMBASE [Ovid], Web of Science, Google scholar and the Cochrane Library) was performed according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines encompassing articles published up to August 2020. A total of 2386 articles were screened.

Results

A total of 48 articles were included in this systematic scoping review. All studies had a prospective design. Five key items in the assessment of flexible ureterorenoscopy were distinguished: ‘Manoeuvrability’ (87.5%), ‘Optics’ (64.6%), ‘Irrigation’ (56.3%), ‘Handling’ (39.6%) and ‘Durability’ (35.4%). After regrouping, every key item could be divided into specific subcategories. However, the quality assessment showed a wide variation in denomination, method of measurement, circumstances of measurement, tools used during measurements, number of measurements performed, number of observers, and units of outcomes.

Conclusion

The research field regarding quality assessment of ureterorenoscopes is heterogeneous. In this systematic scoping review we identified five key parameters: Manoeuvrability, Optics, Irrigation, Handling and Durability, used to grade flexible ureterorenoscopes. However, within these categories we found a wide variety in terms of method of measurements. A standardised, uniform grading tool is required to assess and compare the quality of flexible ureterorenoscopes in the future.

Relevance of Adopting a Hybrid Strategy Mixing Single-Use and Reusable Ureteroscopes for Stones Management: An Economic Study to Support the Best Strategy

Endoscopic procedures such as ureteroscopy (URS) have seen a recent increase in single-use devices. Despite all the advantages provided by disposable ureteroscopes (sURSs), their cost effectiveness remains questionable, leading most teams to use a hybrid strategy combining reusable (rURS) and disposable devices. Our study aimed to create an economic model that estimated the cut-off value of rURS procedures needed to support the profitability of a hybrid strategy (HS) for ureteroscopy. We used a budget impact analysis (BIA) model that estimated the financial impact of an HS compared to 100% sURS use. The model included hospital volume, sterilization costs and the private or public status of the institution. Although the hybrid strategy generally remains the best economic and clinical option, a predictive BIA model is recommended for the decision-making. We found that the minimal optimal proportion of rURS procedures in an HS was mainly impacted by the activity volume and overall number of sterilization procedures. Private and public institutions must consider these variables and models in order to adapt their HS and remain profitable.

Disposable versus Reusable Ureteroscopes: A Prospective Multicenter Randomized Comparison

Purpose

To compare reusable and disposable flexible ureteroscopes in terms of efficacy and safety for patients undergoing Retrograde Intrarenal Surgery (RIRS).

Patients and Methods

Patients with a renal stone eligible for RIRS were enrolled in this multicenter, randomized, clinical trial study. Patients were randomized into two groups: group A (90 patients) underwent RIRS with a reusable flexible ureteroscope and group B (90 patients) were treated with a disposable one.

Results

The patients’ demographics, stone features and pre-operative urine cultures were comparable between the groups. The Stone Free Rates (SFRs) were not significantly different (86.6% and 90.0% for group A and group B, respectively, p=0.11) and the mean cost for each procedure was comparable (2321 € in group A vs 2543 € in group B, p=0.09). However, the days of hospitalization and of antibiotic therapy were higher in group A (p ≤ 0.05). The overall complication rate in group A was 8.8% whilst in group B it was 3.3% (p ≤ 0.05); in particular, group A exhibited a greater number of major complications (Clavien score IIIa-V). The overall postoperative infection rate was 16.6% in group A and 3.3% in group B (p ≤ 0.05). Furthermore, none of the patients in group B developed urosepsis or had a positive blood culture, while 3 patients in group A did (p<0.05).

Conclusion

The use of disposable ureteroscopes is characterized by significantly lower post-operative complications and infection rates, while having comparable costs and SFRs vis à vis reusable ureteroscopes. Clinical Trial Registration Number: ISRCTN92289221.

A Single-Center Prospective Comparative Study of Two Single-Use Flexible Ureteroscopes: LithoVue (Boston Scientific, USA) and Uscope PU3022a (Zhuhai Pusen, China)

Introduction and Objective: Single-use flexible ureteroscopes have the benefit of decreasing infection transmission, avoiding sterilization need, and no maintenance cost. Primary objective was to compare in vivo performance and surgical outcomes with two single-use ureteroscopes: LithoVue (Boston Scientific, USA) and Uscope PU3022a (Zhuhai Pusen, China) with secondary objective being to compare in vivo vision by independent endourologist blinded to ureteroscope manufacturer. Materials and Methods: Fifty patients undergoing retrograde intrarenal surgery with <2 cm renal stones were prospectively allocated: Group 1 (25 patients) for LithoVue and group 2 (25 patients) for Uscope. Pre-, intra-, and postoperative parameters were evaluated. Vision of both ureteroscopes with and without accessory was evaluated by an independent endourologist, blinded to the make of the ureteroscope. Stone clearance was assessed with kidney, ureter, and bladder radiograph (KUB) and ultrasonography KUB at 1 month. Student's t-test for quantitative and chi-square for categorical data was used. Results: Pre- and intraoperative parameters such as need for ureteral dilatation (p > 0.05), ureteral access-sheath size (p = 0.78), accessibility to pelvicaliceal system (p > 0.05), and maneuverability (p > 0.05) were comparable in both groups. Lower-pole access was possible in all cases of LithoVue and slightly difficult in three cases of Uscope (p > 0.5). Intraoperative vision was hazy in four cases of LithoVue and eight cases of Uscope (p = 0.32) during lasing along with three cases of Uscope with accessory (p = 0.24). Blinded endourologist reported more cases of hazy vision with or without accessory or lasing in Uscope arm (p > 0.05). One device had malfunction in LithoVue arm. Complete stone clearance was achieved in all cases at 1 month. Conclusions: We conclude that performance of these two single-use ureteroscopes, LithoVue and Uscope, is comparable in clinical settings with similar clinical outcomes and complications.

Retrograde intrarenal surgery: Past, present, and future

With the recent technological advancements in endourology, retrograde intrarenal surgery has become a more popular procedure for treatment of urolithiasis. Furthermore, since the introduction of new laser systems and advanced flexible ureteroscopy with miniaturized ureteroscopes, the treatment indications for retrograde intrarenal surgery have expanded to include not only larger renal stones of >2 cm but also upper urinary tract urothelial carcinoma, ureteral stricture, and idiopathic renal hematuria. Clinicians must keep up with these trends and make good use of these technologies in the rapidly changing field of endourology. Simultaneously, we must consider the risk of various complications including thermal injury due to laser use, ureteral injury caused by the ureteral access sheath, and radiation exposure during retrograde intrarenal surgery with fluoroscopic guidance. This review focuses on the past, present, and future of retrograde intrarenal surgery and provides many topics and clinical options for urologists to consider.

Flexible ureteroscopy: reuse? Or is single use the new direction?

PURPOSE OF REVIEW

Single-use flexible ureteroscopes (su-fURS) aim at overcoming the main limitations of conventional reusable ureteroscopes in terms of acquisition and maintenance costs, breakages, and reprocessing. However, little data exist to date regarding the superiority of su-fURS at this regard. We aimed to perform a systematic literature review on available su-fURS performance with a focus on clinical data for all articles in the last 10 years.

RECENT FINDINGS

To date, more than 10 different su-fURS are available on the market, with different characteristics and performance. Some of these devices have top-level features, almost catching up with those observed in reusable flexible ureteroscopes. Clinical evidence is mainly available only for two models, LithoVue and Uscope PU3022, and to date it is not strong enough to support routine adoption and use of su-fURS, with a consequent lack of consensus of specific clinical indications. Cost-effectiveness analyses seem to indicate an economic disadvantage in the routine adoption of su-fURS. Environmental issues related to the use of su-fURS also remain to be inquired and addressed.

SUMMARY

Since their introduction, su-fURS have gained widespread popularity. Despite their ability at addressing reusable ureteroscope limitations, high-cost and a substantial lack of evidence are still limiting their routine adoption.

Critical Assessment of Single-Use Ureteroscopes in an In Vivo Porcine Model

Methods

A female pig was placed under general anesthesia and positioned supine, and retrograde access to the renal collecting system was obtained. The LithoVue (Boston Scientific) and Uscope (Pusen Medical) were evaluated by three experienced surgeons, and each surgeon started with a new scope. The following parameters were compared between each ureteroscope: time for navigation to upper and lower pole calyces with and without implements (1.9 F basket, 200 μm laser fiber, and 365 μm laser fiber for upper only) in the working channel and subjective evaluations of maneuverability, irrigant flow through the scope, lever force, ergonomics, and scope optics.

Results

Navigation to the lower pole calyx was significantly faster with LithoVue compared to Uscope when the working channel was empty (24.3 vs. 49.4 seconds, p < 0.01) and with a 200 μm fiber (63.6 vs. 94.4 seconds, p=0.04), but not with the 1.9 F basket. Navigation to the upper pole calyx was similar for all categories except faster with LithoVue containing the 365 μm fiber (67.1 vs. 99.7 seconds, p=0.02). Subjective assessments of scope maneuverability to upper and lower pole calyces when the scope was empty and with implements favored LithoVue in all categories, as did assessments of irrigant flow, illumination, image quality, and field of view. Both scopes had similar scores of lever force and ergonomics.

Conclusions

In an in vivo porcine model, the type of single-use ureteroscope employed affected the navigation times and subjective assessments of maneuverability and visualization. In all cases, LithoVue provided either equivalent or superior metrics than Uscope. Further clinical studies are necessary to determine the implications of these findings.

Evaluation of flexible ureteroscope with an omni-directional bending tip, using a JOYSTICK unit (URF-Y0016): an ex-vivo study

PURPOSE

To compare the range of reach of our newly designed omni-directional ureteroscope (URF-Y0016), compared to the commonly used URF-P6, FlexX2s, and LithoVue™ scopes, in the upper, middle, and lower calyces in an ex-vivo pyelocaliceal model.

METHODS

We fabricated a three-dimensional pyelocaliceal model of the upper, middle, and lower pole calyces using urethane and acrylic resin. The inner surface of the dome of each calyx was engraved with reference lines along eight directions, set at 10° of latitude from the top to the base of the dome, and at angles of 0-90°, to precisely determine the range of reach of each scope. The main feature of the URF-Y0016 scope is the omni-directional bending of the tip of the flexible ureteroscope, with the control of these four directions integrated into a handgun-type control unit with a joystick. The range of reach within each calyx was measured by four expert surgeons.

RESULTS

The URF-Y0016 scope provided a greater range of reach along all directions in the lower pole calyx compared to URF-P6, FlexX2s, and LithoVue™ scopes (p < 0.001), particularly along the anterior-posterior direction in the lower lobe calyx. However, the URF-Y0016 scope did not influence the improvement of reach range in the upper and middle pole calyx compared to URF-P6, FlexX2s, and LithoVue™ scopes (p = 0.08, p = 0.296).

CONCLUSION

The novel design of the URF-Y0016 could improve treatment outcomes for calyceal stones in the lower pole in practice.