A new era: performance and limitations of the latest models of flexible ureteroscopes

The Effect of Reusable Flexible Ureteroscope Aging on the Efficacy and Safety of Retrograde Intrarenal Surgery

Purpose: Reusable flexible ureteroscopes may lose their mechanical functionality through overuse, which is known as "aging of the flexible ureteroscope." Although mechanical deterioration has been shown in several studies, the data about the effect of this situation on the efficacy and safety of retrograde intrarenal surgery (RIRS) are missing. The aim of our study was to evaluate the effect of the aging of flexible ureteroscopes on the efficacy and safety of RIRS. Methods: Patients who had undergone RIRS between 2017 and 2021 at a single center were retrospectively included in the study. Serial surgeries were performed using the same reusable flexible ureteroscope (Storz X2) until it was broken or malfunctioned because of the aging process. Group 1 was formed by the first 10 cases on whom the flexible ureteroscopes were used, representing the youngest period of the instruments, whereas group 2 was composed of the last 10 cases on whom the flexible ureteroscopes were used, representing the oldest phase of the instruments. The operative and postoperative data-including the operation time, hospitalization time, intraoperative complications, postoperative complications, and stone-free rates-were compared between the two groups. Results: A total of five flexible ureteroscopes were included in the study. The number of cases for each flexible ureteroscope ranged between 87 and 133, with a median number of 107 cases. The demographic and clinical properties of patients in both groups were similar. The operation time, lasering time, and total laser pulse were similar between the groups. The stone-free rates in group 1 and group 2 were 82.0% and 78.0%, respectively (p = 0.304). The complication rates were also similar between the groups (p = 0.591). Conclusion: The aging of reusable flexible ureteroscopes did not negatively affect the efficacy and safety of RIRS. Therefore, surgeons may use the reusable types of flexible ureteroscopes until they are totally broken.

Illumination matters part IV: blackout and whiteout in flexible ureteroscopy - first report on a phenomenon observed by PEARLS

PURPOSE

To date, no study has evaluated effects of varying brightness settings on image quality from flexible ureteroscopes submerged in saline. The aim was to evaluate blackout and whiteout occurrences in an in-vitro kidney calyx model.

MATERIAL AND METHODS

We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed enclosed pink in-vitro kidney calyx model submerged in saline. Endoscopic images were captured with ureteroscope tip placed at 5 mm,10 mm and 20 mm distances. The complete range of brightness settings and video capture modes were evaluated for each scope. Distribution of brightness on a grayscale histogram of images was analyzed (scale range 0 to 255). Blackout and whiteout were defined as median histogram ranges from 0 to 35 and 220 to 255, respectively (monitor image too dark or too bright for the human eye, respectively).

RESULTS

Blackout occurred with the P7, Pusen 7.5F, 9.2F and WiScope at all distances, and V3 at 20 mm - with lowest brightness settings. Whiteout occurred with Flex-X2s, V3 and P7 at 5 mm and 10 mm, as well as with V3 and P7 at 20 mm - mostly with highest brightness settings. The Flex-Xc had neither blackout nor whiteout at all settings and distances.

CONCLUSION

Blackout or whiteout of images is an undesirable property that was found for several scopes, possibly impacting diagnostic and therapeutic purposes during ureteroscopy. These observations form a guide to impact a urologist's choice of instruments and settings.

Retrograde Cystonephroscopy for Complex Renal Calculi Using Novel Dual Action Aspiration, Irrigation Cystoscope: Initial Case Series

Introduction Percutaneous nephrolithotomy (PCNL) is the gold standard treatment for kidney stones ≥ 2 cm; however, it remains an invasive procedure with significant risks especially in individuals with severe medical co-morbidities. In contrast, while ureteroscopy is far less morbid, a major impediment to its use for larger calculi is the inability to evacuate the many fragments created during laser lithotripsy. Herein, we describe two patients with large volume calculi and a third high risk patient with a smaller stone that were treated with cystonephroscopy using a recently released, 16Fr flexible cystoscope equipped with dual aspiration and irrigation capabilities. Materials and Methods Three consecutive female patients underwent retrograde cystonephroscopy from June 2021 to July 2021 with a novel 16Fr aspiration enabled flexible cystoscope. Demographic data were collected. Pre-operative and post-operative CT-scan images were reviewed to determine linear stone dimensions and scalene ellipsoid volume. Results The three female patients had an average age of 72.3 years and an American Society of Anesthesiologists (ASA) physical status score of 3. The mean preoperative stone volume was 4950 mm³. The average post-cystonephroscopy stone volume was 217 mm³ resulting in a total stone clearance rate of 97%. No major complications occurred. Average procedure time was 176 minutes. Conclusions Among three high risk female patients, two with large volume calculi, retrograde cystonephroscopy with a novel aspiration-enabled cystoscope allowed for the procedure to be successfully completed solely via a retrograde approach.

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.

[Chinese Expert Consensus Statement on Clinical Evaluation System of Medical Endoscopy]

医用内窥镜的发展速度及普及程度非常快，国际大厂品牌统领内窥镜市场半壁江山，目前国产品牌的市场规模也迅速增长，硬镜、软镜电子化技术迅速发展，逐渐接近国际先进水平。但是，目前适用于评价医用内窥镜的国家标准、行业规定等相关标准缺乏，国内外产品差距缺少定量、明确的认识，国产品牌多而杂，需要对医用内窥镜给予全面、准确的评价。在此背景下，专家组经过科学地遴选和严谨地实践提出了一套科学、系统、适用的标准化医用内窥镜临床评价体系，以期规范化各类内窥镜评价指标。

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

PURPOSE

Reusable flexible-ureteroscopes (fURS) require personnel and budget for processing and repairing, whereas single-use fURS were recently developed. After exclusive reusable fURS since 2011, we experienced high repair costs and single-use fURS were therefore introduced in mid-2017. We aimed to evaluate economic and practical advantages and disadvantages of reusable versus single-use fURS.

MATERIALS AND METHODS

First, we evaluated the incidence of breakage and repairs of reusable fURS in 2017. We assessed the overall operational costs of reusable fURS including purchase, processing, and repairing in our institution from 2011 to 2017. Following our experience, we created a model to compare operation costs/procedure of single-use fURS with reusable fURS depending on repair costs.

RESULTS

In 2017, repair costs of reusable fURS increased by 345% compared with the period 2011-2016, causing: a median unavailability per reusable fURS of 200 days/year (100-249), median number of functioning fURS 0/5-3/5 per operating day, while unavailability of reusable fURS had become the first reason for cancellation of procedure. Since it was introduced, single-use fURS accounted for 59% of the flexible ureteroscopy activity. Taking into account the costs of processing, maintenance and repair, in 2011-2016 versus 2017, the single-use fURS was cost-effective compared with the reusable fURS until the 22nd procedure versus the 73rd procedure, respectively.

CONCLUSIONS

After years of exclusive reusable fURS, the rising incidence of breakage not only increased maintenance costs but also hampered daily activity owing to unavailability of the devices. The introduction of single-use with reusable fURS provided substantial help to maintain our activity.

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

INTRODUCTION

Single-use ureteroscopes have been gaining popularity in recent years. We compare the optics, deflection, and irrigation flow of two novel single-use flexible ureteroscopes-the YC-FR-A and the NeoFlex-with contemporary reusable and single-use flexible ureteroscopes.

METHODS

Five flexible ureteroscopes, YC-FR-A (YouCare Tech, China), NeoFlex (Neoscope, Inc., USA), LithoVue (Boston Scientific, USA), Flex-Xc (Karl Storz, Germany), and Cobra (Richard Wolf, Germany), were assessed in vitro for image resolution, distortion, field of view, depth of field, color representation, and grayscale imaging. Ureteroscope deflection and irrigation were also compared.

RESULTS

The YC-FR-A showed a resolution of 5.04 lines/mm and 4.3% image distortion. NeoFlex showed a resolution of 17.9 lines/mm and 14.0% image distortion. No substantial difference was demonstrated regarding the other optic characteristics between the two. Across all tested ureteroscopes, single-use or reusable, the digital scopes performed best with regard to optics. The YC-FR-A had the greatest deflection at baseline, but lacks two-way deflection. The NeoFlex had comparable deflection at baseline to reusable devices. Both ureteroscopes had substantial loss of deflection with instruments in the working channel. The YC-FR-A had the greatest irrigation rate. The NeoFlex has comparable irrigation to contemporary ureteroscopes.

CONCLUSIONS

The YouCare single-use fiberoptic flexible ureteroscope and NeoFlex single-use digital flexible ureteroscope perform comparably to current reusable ureteroscopes, possibly making each a viable alternative in the future. Newer YouCare single-use flexible ureteroscopes with a digital platform and two-way deflection may be more competitive, while the NeoFlex devices are undergoing rapid improvement as well. Further testing is necessary to validate the clinical performance and utility of these ureteroscopes, given the wide variety of single-use devices under development.

Digital ureteroscopes: technology update

The field of ureteroscopy has undergone a continual evolution since the first ureteroscopes were introduced. Over the past 10 years, we have entered into the digital era of ureteroscopy with both semirigid and flexible options becoming available. The following review looks at the benefits and drawbacks of digital flexible ureteroscopes as well as the current commercially available options.

Papillary ureteral neoplasm of low malignant potential in the upper urinary tract: endoscopic treatment

INTRODUCTION

Papillary ureteral neoplasm of low malignant potential (PUNLMP) is a rare diagnosis, and to our knowledge, has not yet been reported in the upper urinary tract. In this study, we aimed to present our experience in managing a very rare diagnosis, PUNLMP, in the upper urinary tract, with endoscopic treatment.

MATERIALS AND METHODS

Files of patients who received surgery between January 2007 and January 2013 for upper urinary tract tumors were reviewed and patients treated for PUNLMP in the upper urinary tract in 4 urology clinics were reviewed. Patients included in the study had at most 2 tumors in the ureter and had a pathology of PUNLMP.

RESULTS

The study included 11 patients with a mean age of 58.5 years. There were 9 men, and 2 women with a smoking rate of 81.8%. Nine patients (8 in the distal and 1 in the mid ureter) were managed using a semirigid ureteroscope. Two patients (1 with mid ureteral and 1 proximal) were treated using flexible ureteroscopy. The mean hospital stay was 1.56 days. Mean surgical time was 37.18 ± 7.14 minutes. The mean follow-up was 31.5 (range, 7-72) months. In the follow-ups, 3 patients had recurrences of 3, 2, and 4 mm in 9, 15, and 17 months, respectively.

CONCLUSION

For tumors with a low risk of progression and relatively low risk of recurrence, organ-sparing treatments should be the choice of preference. To support our initial findings, randomized controlled studies on larger cohorts should be designed.

Pushing the boundaries of ureteroscopy: current status and future perspectives

Substantial advances in ureteroscopy have resulted in the incorporation of this procedure into routine urological practice in many centres worldwide. Subsequently, an abundance of clinical data and technological progression have enabled the development of novel solutions that have increased the efficacy of ureteroscopy, and reduced associated morbidity and costs. In addition the indications for this retrograde approach have been expanded, and pyelocalyceal diverticulum, infundibular stenosis, urolithiasis in pregnant women or in patients with urinary diversions, as well as upper urinary tract tumours can now be managed using this methodology. New endoscopes are continuously developed, with different manufacturers choosing various technical solutions to further increase the efficacy and safety-and sometimes decrease costs-of ureteroscopy, including miniaturization, inclusion of digital optical systems and dual working channels, and the introduction of disposable apparatus. The holmium laser, currently the most-versatile energy source available, enables tissue incision, tumour ablation, and intracorporeal lithotripsy. Modern ancillary instruments are diverse, flexible, and durable, and novel devices used in daily clinical practice can minimize ascendant migration of stone fragments and, therefore, decrease the failure rate of the retrograde ureteroscopic approach. However, the peak of ureteroscopy evolution seems to remain distant, with further improvement of endoscopes and ancillary instruments, and robot-assisted ureteroscopy representing only some of the areas in which future developments are possible.