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

Opportunities in Primary and Enteric Hyperoxaluria at the Cross-Roads Between the Clinic and Laboratory

Hyperoxaluria is a condition in which there is a pathologic abundance of oxalate in the urine through either hepatic overproduction (primary hyperoxaluria [PH]) or excessive enteric absorption of dietary oxalate (enteric hyperoxaluria [EH]). Severity can vary with the most severe forms causing kidney failure and extrarenal manifestations. To address the current challenges and innovations in hyperoxaluria, the 14th International Hyperoxaluria Workshop convened in Perugia, Italy, bringing together international experts for focused presentation and discussion. The objective of the following report was to disseminate an overview of the proceedings and provide substrate for further thought. The format of this paper follows the format of the meeting, addressing, "PH type 1" (PH1) first, followed by "surgery, genetics, and ethics in PH", then "PH types 2 and 3," (PH2 and PH3) and, finally, "EH." Each session began with presentations of the current clinical challenges, followed by discussion of the latest advances in basic and translational research, and concluded with interactive discussions about prioritizing the future of research in the field to best serve the need of the patients.

Single-use flexible ureteroscopes: practice patterns, attitudes, and preferences for next-generation concepts

Background

Single use flexible ureteroscopes (su-fURS) have emerged as an alternative to reusable flexible ureteroscopes (r-fURS) for the management of upper urinary tract calculi. However, little is known about urologist usage and attitudes about this technology. Through a worldwide survey of endourologists, we assessed practice patterns and preferences for su-fURS.

Methods

An online questionnaire was sent to Endourology Society members in January 2021. The survey explored current su-fURS practice patterns, reasons for/against adoption, and preferences for next generation models including developments in imaging, intra-renal pressure, heat generation, and suction. Responses were collected through QualtricsXM over a 1-month period from surgeons in North America, Latin America, Europe, Asia, Africa, and Oceania. The study was conducted according to the Checklist for Reporting Results of Internet E-Surveys (CHERRIES).

Results

208 (13.9%) members responded to the survey. Most respondents (53.8%) performed >100 ureteroscopies per year. 77.9% of all respondents used su-fURS for less than half of all procedures while only 2.4% used su-fURS for every procedure. 26.0% had never used a su-fURS. Overall, usage was not influenced by a surgeon's geographic region, practice environment, or years of experience. Top reasons for not adopting su-fURS were cost (59.1%) and environmental impact (12.5%). The most desired improvements in design were smaller outer shaft size (19.4%), improved optics and vision (15.9%), and wireless connectivity (13.6%). For next generation concepts, the functions most commonly described as essential or important by respondents was the ability to suction fragments (94.3%) while the function most commonly noted as not important or unnecessary was incorporation of a temperature sensor (40.4%).

Conclusions

su-fURS are not commonly used, even among urologists who perform a high number of fURS. The primary concern for adoption is cost and environmental impact. Suction capability was considered the most important future development.

Single-Use Flexible Ureteroscopes: How Difficult Is It Today to Stay Up to Date? A Pictorial Review of Instruments Available in Europe in 2023

The invention of the flexible ureteroscope (fURS) and its subsequent spread have revolutionized the surgical management of urolithiasis and upper tract urothelial carcinoma (UTUC). During the last few years, single-use flexible ureteroscopes (su-fURSs) have been developed to improve the limitations of reusable fURSs, namely their cost, durability and risk of device contamination. Since the introduction of the first fully disposable digital fURS, several su-fURSs have been developed by various manufacturers. In this pictorial review, we combined the different physical and technical features of su-fURSs currently available on the market with Food and Drug Administration (FDA) and European Conformity (CE) approval, in order to help surgeons choose the appropriate device according to each case requirement and personal preferences. To the best of our knowledge, 17 su-fURSs with CE and FDA approval have been developed to date.

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.

Single-Use Ureteroscopy and Environmental Footprint: Review of Current Evidence

PURPOSE OF REVIEW

Ureteroscopy is a well-established treatment modality for kidney and ureteric calculi in addition to playing a key role in upper tract cancer diagnostics. Traditional reusable flexible ureteroscopes are technologically advanced and expensive pieces of equipment that require repeat sterilisation and periodical repair. These issues have led to the development of single-use flexible ureteroscopes that are disposed of after each case. Whilst this may be advantageous in many respects, the environmental impact of such technology is yet to be fully determined. The aim of this review is to therefore identify and summarise the available literature concerning the environmental footprint of single-use ureteroscopy.

RECENT FINDINGS

To identify the latest research on this topic, a systematic search of world literature was conducted using the Medline, Embase, and PsycINFO databases. PRISMA guidelines were followed and articles were assessed by all authors and relevant study results were included in a narrative format. Only one relevant article was identified and included. This study found that a single-use flexible ureteroscope (LithoVue^TM by Boston Scientific) generated an equivalent amount of carbon dioxide per case to a contemporary reusable flexible ureteroscope. Literature concerning the environmental footprint of single-use ureteroscopy is worryingly lacking. No conclusions can be definitively drawn from a single study and further research is imperative given the global climate crisis and the significant contribution that healthcare services have to the environmental problem.

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.

Comparison of Surgical Outcomes between Single-Use and Reusable Flexible Ureteroscopes for Renal Stone Management: A Systematic Review and Meta-Analysis

Background and Objectives: Disposable flexible ureteroscopes have been widely used because of their cost-effectiveness and higher sterility potential compared with reusable flexible ureteroscopes. This study aimed to compare the surgical outcomes and complication rates in patients who undergo reusable or disposable flexible ureteroscopic stone surgeries (fURS) for urinary stone disease. Materials and Methods: A systematic review and meta-analysis were conducted under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. This systematic review was registered with PROSPERO (CRD42022331291). Clinical trials comparing reusable and disposable fURS for stone disease were found from PubMed, EMBASE, Cochrane Library, and the Web of Science up to March 2022. Participants were patients with upper urinary tract stones; the interventions were reusable or disposable fURS. Outcomes, including stone-free rate, operation time, length of hospital stay, and complication rate, were compared for analysis. Results: Overall, 111 studies were identified, but after removing duplicate studies, 75 studies remained. Thirty-two of these studies were excluded. Of the 43 screened studies, 11 met the eligibility criteria. There was no difference in the stone-free rate (SFR) between disposable and reusable fURS (p = 0.14; OR = 1.36; 95% CI, 0.9 to 2.04). For operation time, no difference was identified between reusable and disposable fURS groups (p = 0.12; MD = -5.31; 95% CI, -12.08 to 1.46). For hospital stay, there was also no difference between the two groups (p = 0.61; MD = -0.03; 95% CI, -0.17 to 0.10). There was no significant difference in complication rate between the two groups (p = 0.85; OR = 0.95; 95% CI, 0.56 to 1.61). Conclusions: There were no differences in the SFR, operation time, length of hospital stay, and complication rate between reusable and disposable fURS. Disposable fURS may be a comparable alternative to reusable fURS.

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.

Evolution of Single-Use Urologic Endoscopy: Benchtop and Initial Clinical Assessment of a New Single-Use Flexible Cystoscope

Introduction Office cystoscopy is one of the most frequently performed procedures by a urologist. However, single-use cystoscopes remain quite undeveloped. Ambu® has developed single-use broncoscopes, rhinolaryngoscopes and duodenoscopes. Recently, they released a single-use cystoscope. In this study, we performed a benchtop and initial clinical assessment of the Ambu® aScope™ (4) Cysto single-use cystoscope. Methods Ten new, never-used Ambu® aScope™ (4) Cysto single-use cystoscopes were assessed for optical performance, maximal tip flexion and irrigation flow rate with empty working channel, 365μm laser fiber, 0.035in hydrophilic-tipped wire, 1.9Fr nitinol basket and a 1.8mm flexible stent grasper. All cystoscopes were then fully flexed 25 times in each direction, and maximal flexion angles were re-measured with and without instruments. Optical resolution, distortion, and depth of field was measured and compared to our reusable digital flexible cystoscopes. Assessment of clinical use was performed for inpatient bedside procedures using a Likert feedback survey and the NASA Task-Load-Index. Results Maximal upward flexion exceeded 200^○ and 160^○ for all working instruments in upward and downward flexion. Downward flexion demonstrated different flexion between instrument groups in pre- and post-cycling (p<0.001). There was no clinical difference between the pre- or post-cycling flexion. Flow rate decreased with increasing working instrument size (p<0.001). The Olympus HD cystoscope resolution was superior at 3mm and 5mm distance, but not at other distances. The Ambu® scope was superior to the Olympus SD scope at all distances except 3mm. The aScope™ (4) Cysto had higher Likert scale survey scores for clinical use. Conclusions The new Ambu® single-use cystoscope demonstrates good flexion across instruments and comparable optics to reusable cystoscopes. Additionally, initial inpatient bedside use of the aScope™ (4) Cysto and Monitor system compares favorably to the Olympus reusable cystoscope. Further testing in clinical scenarios such as hematuria, urothelial carcinoma and operative endoscopy is warranted.

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.

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.