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

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.

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.

Single-use flexible ureteroscope provides an alternative treatment for upper urinary calculi: A systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the efficacy and safety of single-use flexible ureteroscope and reusable flexible ureteroscope for upper urinary calculi.

METHODS

We conducted a meta-analysis that had a comprehensive search in PubMed, Embase, Cochrane Library, Web of Science, and WanFang databases from 2000/01/01 to 2023/06/01 for available randomized controlled trials. "Ureteroscopes," "Flexible Ureteroscope," "Single-use," and "Upper Urinary Calculi" were used as the major keywords for the search. Review Manager 5.0 and STATA 12.0 were used for calculation and statistical analysis.

RESULTS

A total of 9 randomized controlled trials comprising 1293 participants were included in our meta-analysis. Single use-FURS had better results in stone-free rate (relative risk: 1.08, 95% confidence interval: [1.02, 1.15], P = .02) and postoperative infection (relative risk: 0.41, 95% confidence interval: [0.23, 0.72], P = .002). Operative time, hemoglobin decline, postoperative serum creatinine, postoperative hospital stay, and overall complication after surgery showed no significant differences between the 2 procedures (P > .05).

CONCLUSION

Single-use flexible ureteroscope provides a valuable alternative to reusable flexible ureteroscope in upper urinary calculi with its better visual field performance and manipulation, opening a new technological revolution for kidney stone treatment.

International Alliance of Urolithiasis guideline on retrograde intrarenal surgery

OBJECTIVES

To set out the second in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis that concerns retrograde intrarenal surgery (RIRS), with the aim of providing a clinical framework for urologists performing RIRS.

MATERIALS AND METHODS

After a comprehensive search of RIRS-related literature published between 1 January 1964 and 1 October 2021 from the PubMed database, systematic review and assessment were performed to inform a series of recommendations, which were graded using modified GRADE methodology. Additionally, quality of evidence was classified using a modification of the Oxford Centre for Evidence-Based Medicine Levels of Evidence system. Finally, related comments were provided.

RESULTS

A total of 36 recommendations were developed and graded that covered the following topics: indications and contraindications; preoperative imaging; preoperative ureteric stenting; preoperative medications; peri-operative antibiotics; management of antithrombotic therapy; anaesthesia; patient positioning; equipment; lithotripsy; exit strategy; and complications.

CONCLUSION

The series of recommendations regarding RIRS, along with the related commentary and supporting documentation, offered here should help provide safe and effective performance of RIRS.

Influencing factors of acute kidney injury following retrograde intrarenal surgery

PURPOSE

To investigate the influencing factors of acute kidney injury (AKI) following retrograde intrarenal surgery (RIRS).

METHODS

The data of patients who underwent RIRS for kidney stones between January 2018 and June 2022 at two tertiary centers were retrospectively analyzed. Demographic data of patients were obtained. According to kidney disease: Improving Global Outcomes (KDIGO) criteria, those with and without AKI were divided into two groups. Preoperative, intraoperative, and postoperative predictive factors of patients were investigated between the groups. In addition, the influencing factors of AKI were examined by multivariate analysis.

RESULTS

This study included 295 (35.7%) women and 532 (64.3%) men. The mean age was 50.03 ± 15.4 years (range 18-89), and mean stone size was 15.5 ± 6.1 mm (range 6-47). Overall, 672 of patients (81.3%) were stone-free after the initial treatment. According to KDIGO, 110 of patients (13.3%) had AKI during the postoperative period. Univariate analysis showed that stone size (P = .003), previous stone surgery (P = .010), renal malformations (P = .017), high operative time (P =  < .001), high preoperative creatinine value (P = .036), intraoperative complications (P = .018), and postoperative urinary tract infection (P = .003) had significant influence on the AKI after RIRS. Multivariate analysis excluded previous stone surgery, high preoperative creatinine value, renal malformations, and intraoperative complications from the logistic regression model, whereas other factors maintained their statistically significant effect on AKI, indicating that they were independent predictors.

CONCLUSIONS

Stone size, operative time, postoperative urinary tract infection, and diabetes mellitus are significant predictors of AKI. During RIRS, urologists should consider the factors that increase the risk of AKI and evaluate the treatment outcomes based on these factors.

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.