Next-Generation Single-Use Ureteroscopes: An In Vitro Comparison

Initial experience of comparison between two slimmest single-use flexible ureteroscopes: Indoscope Sleek (Bioradmedisys™) Versus Uscope PU3033A (Pusen™): A single-center prospective study

PURPOSE

A single-use digital flexible ureteroscope (fURS) has become a cost-effective alternative option to reusable fURS. The requirement of large-diameter access sheath for passage of 9.5 Fr single-use fURS has not always achieved in the first attempt in all cases leading to stage stone clearance. Recently, two slimmest single-use digital disposable fURSs have been introduced by Bioradmedisys™ and Pusen™ to mitigate the accessibility problem, without or with small size access sheath. Primary objective was to compare in vivo performance and surgical outcomes with two single-use fURS: 7.5Fr Indoscope (Bioradmedisys™, Pune, India) and 7.5Fr Uscope PU3033A (Pusen, Zhuhai, China).

METHODS

60 patients undergoing Retrograde Intrarenal Surgery (RIRS) with < 2 cm renal stones were prospectively randomized into: Group A (30 patients) for Indoscope and Group B (30 patients) for Uscope PU3033A. Pre-operative, intra-operative, and post-operative parameters were evaluated. In vivo visibility and maneuverability were rated on 5-point Likert scale by the operating surgeon. At one-month stone clearance was assessed with ultrasound and X-ray KUB. Data were analyzed using SPSS 23.0.

RESULTS

Patient demographics and stone characteristics were comparable in both groups. Indoscope had significantly higher visibility (p < 0.05) than Uscope; however, the maneuverability scores were comparable between both the groups (p > 0.05). 28 patients in group A and 26 patients in group B achieved complete stone clearance (p = 0.38). Scope failure was observed in 1 case of group B (p = 0.31).

CONCLUSION

We conclude that 7.5Fr Indoscope has better vision than 7.5Fr Uscope and the rest of in vivo performances were comparable with similar outcomes and complications among both scopes.

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-X^C®, 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 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.

Innovations in Kidney Stone Removal

Urolithiasis is a common clinical condition, and surgical treatment is performed with different minimally invasive procedures, such as ureteroscopy, shockwave lithotripsy and percutaneous nephrolithotomy. Although the transition from open surgery to endourological procedures to treat this condition has been a paradigm shift, ongoing technological advancements have permitted further improvement of clinical outcomes with the development of modern equipment. Such innovations in kidney stone removal are new lasers, modern ureteroscopes, development of applications and training systems utilizing three-dimensional models, artificial intelligence and virtual reality, implementation of robotic systems, sheaths connected to vacuum devices and new types of lithotripters. Innovations in kidney stone removal have led to an exciting new era of endourological options for patients and clinicians alike.

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.

Repair Rate and Associated Costs of Reusable Flexible Ureteroscopes: A Systematic Review and Meta-analysis

Context

The refined mechanics of a flexible ureteroscope (fURS) are vulnerable to damage. Sending the fURS for repair is costly and has driven interest toward estimating the resources used for fURS repairs.

Objective

To systematically review available literature and to estimate the total weighted repair rate of an fURS and the average repair cost per ureteroscopy.

Evidence acquisition

A systematic review was conducted by searching the MEDLINE, Embase, Web of Science, and Cochrane Library databases. The average costs of all repairs identified in the included studies were extracted. A random-effect model was used to calculate the pooled total fURS repair rate. The total weighted repair rate and average cost per repair were multiplied to provide an average cost of repair per ureteroscopy procedure.

Evidence synthesis

We identified 18 studies that fulfilled the inclusion criteria, which included 411 repairs from 5900 investigated ureteroscopy procedures. The calculated weighted repair rate was 6.5% ± 0.745% (95% confidence interval: 5.0–7.9%; I² = 75.3%), equivalent to 15 ureteroscopy procedures before repair. The average cost per repair was 6808 USD; according to the weighted repair rate of 6.5%, this corresponds to an average repair cost of 441 USD per procedure. Egger’s regression test did not reveal a significant publication bias (p = 0.07).

Conclusions

This is the first meta-analysis to estimate the repair rate of the fURS used for ureteroscopy. Our analysis demonstrates a repair rate of 6.5%, equivalent to 15 ureteroscopy procedures between fURS repairs and a repair cost of 441 USD per procedure. Ureteroscopy practices should consider fURS breakage rates and repair costs to optimize the use of reusable versus disposable devices.

Patient summary

We reviewed available literature investigating the repair rate of a flexible ureteroscope (fURS). We found that fURSs are sent for repair after every 15 ureteroscopy procedures, corresponding to 441 USD per procedure in repair cost.

Disposable Ureteroscopes in Urology: Current State and Future Prospects

Ureteroscopy is the most common surgical modality for stone treatment. Reusable flexible ureteroscopes are delicate instruments that require expensive maintenance and repairs. Multiple single use ureteroscopes have been developed recently to combat the expensive and time-intensive sterilization and repair of ureteroscopes. Although multiple studies have looked at different aspects of reusable and single use ureteroscopes, there is significant heterogeneity in performance measures and cost between the 2 categories, and neither has a clear advantage. Both can be used successfully, and individual and institution level factors should be considered when deciding which ureteroscope to use.

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.

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.

Reusable, Single-Use, or Both: A Cost Efficiency Analysis of Flexible Ureterorenoscopes After 983 Cases

Objectives: To determine which flexible ureterorenoscopy program would be most cost-efficient in our center, a cost efficiency analysis and a formula to assess cost efficiency feasibility of a hybrid model were performed. Methods: Total cost per case of reusable flexible ureterorenoscopes (rfURS) was retrospectively calculated and compared with two single-use flexible ureterorenoscopes (sufURS) marketed. A mathematical formula was developed from our data to identify the necessary increase of use of rfURS (NIU-rfURS) to be cost-efficient in a hybrid system utilizing sufURS for only high-risk-of-breakage cases. Results: In 57 months, 983 procedures were performed using 4 digital rfURS (Flex-XC; Storz), necessitating 45 repairs, with a total repair cost of €256.809. Including the capital investment of €24.000 per scope and €60 per sterilization cycle, the cost per case averaged €419 after 983 cases. Consistently using sufURS would have cost 55% to 127% more (respectively, Uscope PU3022^® and Lithovue^® at €650 and €950 manufacturer suggested retail price). On a per case analysis, the cost was initially extremely high, but declined to reach a plateau around €480 after ∼400 cases. After 155 or 274 procedures, a rfURS program appeared more cost-efficient than consistently using Lithovue or Uscope PU3022, respectively. Based on our data and formula, if we would hypothetically use Uscope PU3022 or Lithovue for 15% of the cases, the NIU-rfURS is, respectively, 28% or 74% (∼6 or 16 cases). The NIU-rfURS increases exponentially with an increased use of sufURS. Conclusion: Consistently using rfURS is more cost-efficient than the constant use of sufURS after 155 to 274 cases. We describe the first mathematical formula that allows a calculation and feasibility assessment of using both reusable and disposable fURS. To identify whether a hybrid system may be a feasible cost-efficient alternative to a rfURS-only program, any center can calculate the NIU-rfURS by entering center-specific data in the formula.

Single-use flexible ureteroscopes: how to choose and what is around the corner?

PURPOSE OF REVIEW

The pace of technology development with single-use endoscopy has led to a range of disposable ureteroscopes. We review the development of single-use scopes, deconstruct the basic design and functional characteristics of available devices, and discuss future directions for next-generation platforms.

RECENT FINDINGS

Currently available devices are differentiated on the basis of several core features. The optical, deflection and irrigation characteristics are marginally different with no device clearly superior in every category. Studies comparing single-use ureteroscopes in patients linked to outcomes are limited. The incorporation of next-generation technologies into these platforms include sensors to monitor intrarenal pressure and temperature, suction of fluid and fragments, and computer vision for artificial intelligence.

SUMMARY

Each ureteroscope has specific features that may be advantageous in different circumstances. Single-use devices could transform the ureteroscope from a visual conduit to a transformative surgical instrument that improves outcomes and reduces 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.

Evaluation of a new disposable flexible ureterorenoscope and comparison to an established disposable flexible ureterorenoscope: a prospective, observational study

PURPOSE

To objectively and subjectively assess the performance and surgical outcomes of the new Innovex EU-scope™ single-use digital flexible ureteroscope (fURS).

METHODS

A prospective cohort study was carried out (August 2019 to May 2020). The new single-use fURS (Innovex Medical Devices Co. Shanghai, China) was analysed with regard to visibility, manoeuvrability, laser interference and overall performance using a validated Likert scale. Outcomes are compared to the LithoVue™ (Boston Scientific, Marlborough, MA).

RESULTS

One hundred patients were included in this study. 50 cases underwent retrograde fURS using the Innovex EU-scope™ and 50 with the LithoVue™. There were no differences in the patient demographics data, or operative data between the two groups. The Innovex EU-scope™ scored higher visibility scores compared to the LithoVue™, median 4, interquartile range (IQR) (4-4), vs. 3.5, IQR (3-5), p = 0.5086. Both scopes had similar manoeuvrability scores. The Innovex EU-scope™ scored significantly lower with regard to comfort compared to the LithoVue, median 4 IQR (3-4) vs. 4.5 IQR (4-5), p = 0.0445. Whereas, laser interference, affected the Innovex much less than the LithoVue™. Both scopes scored well for overall performance. The median overall performance score for the Innovex was 4 IQR (4-4) vs. 4 IQR (4-5).

CONCLUSIONS

This Innovex EU-scope™ has good objective and subjective visibility and manoeuvrability profiles. This single-use flexible ureteroscope may achieve similar clinical outcomes to an established single use instrument.

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.

Device profile of the LithoVue single-use digital flexible ureteroscope in the removal of kidney stones: overview of safety and efficacy

Introduction: Flexible ureteroscopy is a commonly performed urologic procedure for visualization and treatment of the upper urinary tracts. Traditionally, ureteroscopy has been performed with reusable scopes, which have large initial purchasing costs. LithoVue was the first widely adopted single-use flexible ureteroscope clinically available in 2016 and has caused reevaluation of this paradigm. Areas covered: This review is an objective assessment of the LithoVue single-use ureteroscope based on available studies at the time of publication. The authors searched major databases for papers that included the term 'LithoVue' and included relevant papers. The state of the market, technical specifications, results from clinical studies and cost analyses, and competitors are discussed. Expert opinion: The LithoVue single-use flexible ureteroscope has comparable clinical performance to existing reusable ureteroscopes based on available data. Direct clinical comparisons to competing single-use ureteroscopes, many of which are relatively new, are limited. In numerous pre-clinical studies LithoVue performed favorably compared to available competitors. Cost analyses suggest that benefit of single-use ureteroscopes is institution-specific, and will likely be favorable at a low volume of cases and with high local costs for repairs of reusable scopes.

Single-Use Versus Reusable Digital Flexible Ureteroscopes for the Treatment of Renal Calculi: A Prospective Multicenter Randomized Controlled Trial

Objective: To compare the efficacy and safety of a single-use digital flexible ureteroscope (f-URS) and a reusable digital f-URS (URF-V) for the treatment of renal stones in adults. Patients and Methods: In this randomized open-label noninferiority trial, we randomly selected patients with renal stones to receive ureteroscopy through a single-use digital f-URS (ZebraScope^™; Happiness Workshop, Beijing, China) or a URF-V (Olympus, Tokyo, Japan). The primary endpoint was the 1-month postsurgical stone-free rate (SFR). The secondary efficacy endpoints assessed were the high-quality rate of images, the eligible rate of operability, the operative time, and the length of hospital stay. The safety outcomes assessed were the presence of postoperative complications, adverse events (AEs), and serious AEs (SAEs). The noninferiority margin was set at -10%. Results: In total, 126 patients completed the study (i.e., 63 patients in each group). The demographic and preoperative parameters were comparable between the two groups. The 1-month SFR was 77.78% for the ZebraScope group and 68.25% for the URF-V group (two-sided 95% confidence interval [CI]: -5.95 to 25.01). The high-quality rate of images and the eligible rate of operability were 100% in both groups (two-sided 95% CI: -5.27 to 5.35). There was no difference between the two groups in the operative time (p = 0.687), the length of hospital stay (p = 0.430), the presence of postoperative complications (p = 0.310), the presence of AEs (p = 0.709), and the presence of SAEs (p = 0.648). The most important and fatal SAE was acute urinary tract obstruction. Conclusion: The single-use digital f-URS (ZebraScope) appears to be at least noninferior to URF-V regarding the 1-month SFR, the high-quality rate of images, and the eligible rate of operability. Single-use digital f-URSs are an effective and safe alternative to URF-V.

A comprehensive literature-based equation to compare cost-effectiveness of a flexible ureteroscopy program with single-use versus reusable devices

PURPOSE

To critically review all literature concerning the cost-effectiveness of flexible ureteroscopy comparing single-use with reusable scopes.

MATERIALS AND METHODS

A systematic online literature review was performed in PubMed, Embase and Google Scholar databases. All factors potentially affecting surgical costs or clinical outcomes were considered. Prospective assessments, case control and case series studies were included.

RESULTS

741 studies were found. Of those, 18 were duplicated and 77 were not related to urology procedures. Of the remaining 646 studies, 59 were considered of relevance and selected for further analysis. Stone free and complication rates were similar between single-use and reusable scopes. Operative time was in average 20% shorter with digital scopes, single-use or not. Reusable digital scopes seem to last longer than optic ones, though scope longevity is very variable worldwide. New scopes usually last four times more than refurbished ones and single-use ureterorenoscopes have good resilience throughout long cases. Longer scope longevity is achieved with Cidex and if a dedicated nurse takes care of the sterilization process. The main surgical factors that negatively impact device longevity are lower pole pathologies, large stone burden and non-use of a ureteral access sheath. We have built a comprehensive fi nancial costeffective decision model to fl exible ureteroscope acquisition.

CONCLUSIONS

The cost-effectiveness of a fl exible ureteroscopy program is dependent of several aspects. We have developed a equation to allow a literature-based and adaptable decision model to every interested stakeholder. Disposable devices are already a reality and will progressively become the standard as manufacturing price falls.

Characteristics of current digital single-use flexible ureteroscopes versus their reusable counterparts: an in-vitro comparative analysis

Background

Single-use flexible ureterorenoscopes (fURSs) have been recently introduced aiming to offer solutions to the sterilization, fragility and cost issues of the reusable fURSs. In order to be a viable alternative, the single-use scopes must prove similar capabilities when compared to their reusable counterparts. The goal of our in-vitro study was to compare the current reusable and single-use digital fURSs regarding their deflection, irrigation and vision characteristics.

Methods

We compared in-vitro 4 single-use fURSs-LithoVue™ (Boston Scientific, Marlborough, Massachusetts, USA), Uscope™ (Zhuhai Pusen Medical Technology Co. Ltd., Zhuhai, Guangdong Province, China), NeoFlex™ (NeoScope Inc, San Jose, California, USA) and ShaoGang™ (YouCare Technology Co. Ltd., Wuhan, China) versus 4 reusable fURSs-FLEX-X^c (Karl Storz SE & Co KG, Tuttlingen, Germany), URF-V2 (Olympus, Shinjuku, Tokyo, Japan), COBRA vision and BOA vision (Richard Wolf GmbH, Knittlingen, Germany). Deflection and irrigation abilities were evaluated with different instruments inserted through the working channel: laser fibres (200/273/365 µm), retrieval baskets (1.5/1.9/2.2 Fr), guide wires [polytetrafluoroethylene (PTFE) 0.038 inch, nitinol 0.035 inch] and a biopsy forceps. A scoring system was designed to compare the deflection impairment. Saline at different heights (40/80 cm) was used for irrigation. The flow was measured with the tip of the fURS initially straight and then fully deflected. The vision characteristics were evaluated (field of view, depth of field, image resolution, distortion and colour representation) using specific target models.

Results

Overall, the single-use fURSs had superior in-vitro deflection abilities than the reusable fURSs, in most settings. The highest score was achieved by NeoFlex™ and the lowest by ShaoGang™. PTFE guide wire had most impact on deflection for all fURSs. The 200 µm laser fibre had the lowest impact on deflection for the single-use fURSs. The 1.5 Fr basket caused the least deflection impairment on reusable fURSs. At the end of the tests, deflection loss was noted in most of the single-use fURSs, while none of the reusable fURSs presented deflection impairment. ShaoGang™ had the highest irrigation flow. Increasing the size of the instruments occupying the working channel led to decrease of irrigation flow in all fURSs. The impact of maximal deflection on irrigation flow was very low for all fURSs. When instruments were occupying the working channel, the single-use fURSs had slightly better in-vitro irrigation flow than the reusable fURSs. The field of view was comparable for all fURSs, with LithoVue™ showing a slight advantage. Depth of field and colour reproducibility were almost similar for all fURSs. ShaoGang™ and Uscope™ had the lowest resolution. FLEX X^c had the highest image distortion while LithoVue™ had the lowest. Partial field of view impairment was not for Uscope™ and ShaoGang™.

Conclusions

In-vitro, there are differences in technical characteristics of fURSs. It appears that single-use fURSs deflect better than their reusable counterparts. Irrespective of deflection, the irrigation flow of the single-use fURSs was slightly superior to the flow of the reusable fURSs. Overall, reusable fURSs had better vision characteristics than single-use fURSs. Further in-vivo studies might be necessary to confirm these findings.

Single use versus reusable digital flexible ureteroscopes: A prospective comparative study

OBJECTIVES

To compare the performance and surgical outcomes of two different single-use digital flexible ureteroscopes with a reusable video flexible ureteroscope.

METHODS

Patients undergoing retrograde flexible ureteroscopy at Nepean Hospital, Sydney, Australia, were included in this study. Three different flexible ureteroscopes were used in this study: (i) single-use digital LithoVue (Boston Scientific, Marlborough, MA, USA); (ii) single-use digital PU3022A (Pusen, Zhuhai, China); and (iii) reusable digital URF-V2 (Olympus, Tokyo, Japan). Visibility and maneuverability was rated on a 5-point Likert scale by the operating surgeon. Operative outcomes and complications were collected and analyzed.

RESULTS

A total of 150 patients were included in the present study. Of these, 141 patients had ureteroscopy for stone treatment, four for endoscopic combined intrarenal surgery and five for diagnostic/tumor treatment. There were 55 patients in the LithoVue group, 31 in the PU3022A group and 64 patients in the Olympus URF-V2 group. The URF-V2 group had higher visibility scores than both the single-use scopes and higher maneuverability scores when compared with the PU3022A. The LithoVue had higher visibility and maneuverability scores when compared with the PU3022A. There were no differences in operative time, rates of relook flexible ureteroscopes, scope failure or complication rates observed.

CONCLUSIONS

Single-use digital flexible ureteroscopes have visibility and maneuverability profiles approaching that of a reusable digital flexible ureteroscope. Single-use flexible ureteroscopes achieve similar clinical outcomes to the more expensive reusable versions.

Single-Use Ureteroscopes

A PubMed search using the terms "single use" and "ureteroscope" was performed to identify published studies on this topic. In addition, the abstracts of the annual meeting of the World Congress of Endourology and the American Urologic Association since 2010 were reviewed. Here we present a review of published studies on single-use ureteroscopes.

In vitro, in vivo, and clinical tests of a novel flexible ureteroscope for the diagnosis and treatment of kidney and ureteral diseases

Purpose

Despite advances in flexible ureteroscopy, the high cost and long repair time of ureteroscopes limit their use in the urology. We compared the performance of a novel flexible ureteroscope (fURS) 'HF-EH' with that of the two contemporary fURSs 'URF-P6' and 'COBRA'.

Materials and Methods

We compared in vitro measurements of deflection angle, irrigation flow rate, and image quality between HF-EH and URF-P6 while also inspecting renal collecting systems in five female pigs. For clinical testing, we performed retrograde intrarenal surgeries using HF-EH in four patients. Experienced urologists compared performance parameters (irrigation, convenience, and maneuverability) between the HF-EH and COBRA.

Results

The flow rate of HF-EH (21.0 mL/min) was worse, and its resolution (1.59 line pairs/mm) was inferior to that of URF-P6 (28.7 mL/min and 3.17 line pairs/mm, respectively). However, HF-EH was superior to URF-P6 in terms of loss of deflection angle with the insertion of accessories (1.8% vs. 12.7%). In vivo and clinical testing revealed that the performance parameters of HF-EH were slightly inferior to those of conventional domestic fURSs. We successfully performed retrograde intrarenal surgeries using HF-EH in four patients and achieved stone-free statuses in two. None of the patients exhibited any procedure-related complications.

Conclusions

Although we observed that two of the three performance parameters of the novel ureteroscope 'HF-EH' were inferior to those of the conventional ureteroscope, we successfully used HF-EH to perform retrograde intrarenal surgeries in patients. Further studies on performance and durability are warranted for making HF-EH commercially available.

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.