Fiber Optic Flexible Ureteroscope Research Articles

Being all-seeing gymnast within kidney cavity: analysis of the optical and flexibility characteristics trends of 61 flexible ureteroscopes over four decades.

The purpose of this review is to analyze the trend in optical features and flexibility changes of flexible ureteroscopes over the past decades, and determine the correlation of individual parameters with release period as well as with dimensional parameters. Flexible ureteroscopes mentioned in the literature or those commercially available were searched. To minimize the search bias, the instruments were grouped by release date time-periods of < 2000 year, 2000-2009, 2010-2019, and 2020 onwards. The final review included only those instrument models for which data on minimum and maximum depth of field, field of view, direction of view, and deflection degree had been determined. The correlation among features investigated as well as with release period was also determined. 61 models of flexible ureteroscopes (27 fibreoptic and 34 digital scopes) were included. Among the different features investigated among fiberoptic endoscopes, minimum depth of field positively and negatively correlated with channel size and field of view, respectively, whereas maximum depth of view and field of view positively correlated with overall shaft and deflection degree, respectively. Up and down deflection strongly correlated with each other and both were negatively proportional to the distal tip size. For the digital endoscopes, minimum depth of field negatively and positively correlated with distal tip size and working length, respectively. Maximum depth of field positively correlated with field of view, whereas the latter was negatively proportional to the overall shaft. As for the fiberoptic counterparts, up and down deflection strongly correlated with each other. Field of view, up and down deflection of fiberoptic flexible ureteroscopes, were significantly increased among fiberoptic and digital endoscopes over decades. As flexible ureteroscopy technology has evolved, there has been a trend towards increasing field of view with up and down deflection. Given the importance of scope ergonomics, one aspect of this popularity is the improvement of optical characteristics and deflection degree, which significantly correlates with the release period.

Breakage Costs in Flexible Ureteroscopy: Digital vs. Fiberoptic Modalities

To compare the maintenance costs of digital flexible ureteroscopes (DFU) versus fiberoptic flexible ureteroscopes (FFU) to understand the long-term financial impact associated with breakage in a flexible ureteroscopy (f-URS) program. Data for breakage of FFU and DFU at an academic institution from 2019 to 2021 were obtained from our vendor (Karl Storz) and analyzed by month. Correlation test was used to evaluate significant differences in number of procedures, number of breakage events, breakage rates, and repair cost per month. Cumulative analyses were utilized to examine the number of procedures before failure (time to failure - TTF) and repair costs per procedure (RCpP). We performed a total of 2,154 f-URS, including 1,355 with FFU and 799 with DFU (P<.001). Although we found a higher number of breakage events in FFU (n=124) than DFU (n=73) (P<.001), the overall breakage rate was similar, 9.9% vs. 8.8%, respectively (P=0.86). On cumulative analysis, both modalities reached the same TTF plateau (11 cases) after 18 months. After 400 cases, the RCpP for DFU was 1.25 times higher than for FFU (P=0.04). Overall, we found no difference in overall scope breakage rates between DFU and FFU. Although there was no difference in TTF over time, at the beginning DFU displayed considerable higher durability, leading to lower RCpP. Furthermore, DFU's endurance leveled off to FFU over time, resulting in higher RCpP after 400 cases. This finding may be explained by the presence of renewed scopes after repair.

Current Disposable Ureteroscopes: Performance and Limitations in a Standardized Kidney Model.

Objectives: Due to the increasing fragility of the instruments and rising concerns about the sterility of reprocessable scopes, several single-use devices for flexible ureteroscopy have been introduced. In this study, we compare currently available disposable digital and fiberoptic flexible ureteroscopes with a contemporary reusable fiberoptic device. Materials and Methods: LithoVue™, Pusen Uscope® (UE3011, UE3022), Flexor®Vue™, and a reusable fiber optic flexible ureteroscope (BOA vision®) were tested in kidney models. The setup included (1) visualization of all calices (correct assignment of colored pearls) and (2) the extraction of human calculi with a standard disposable extraction device (NGage®). We documented the effective visualization, stone extraction, and times to completion. In addition, the surgeons' workload and performance were determined using the National Aeronautics and Space Administration-Task Load Index. Results: In visualizing and identifying calices, the LithoVue and both generations of the Uscope performed similarly, but time to completion was significantly longer for all single-use devices in comparison with the Boa Vision. LithoVue retracted stones almost as well as the reusable scope (97% vs 95%/82%/96% stone clearance), while accessibility was impeded using Uscope UE3011, as reflected by the retrieval time per stone (73 vs 102 seconds/stone). This disadvantage has, however, been overcome with the new Uscope Generation UE3022, showing a retrieval time of only 65 seconds per stone, excelling over the reusable scope in this category. The Uscope UE3022 image quality was also rated best, but showed no significant difference. Conclusions: In comparison with disposable ureteroscopes available, LithoVue offers performance and characteristics similar to a reusable device, while the FlexorVu's performance does not yet yield satisfactory results for clinical use. The first generation of Uscope exhibits potential, but requires further technical improvements to match the performance of a reusable device. With the new-generation UE3022, Pusen has made significant improvement and offers a quality comparable with the LithoVue's.

Visual clarity of irrigants used during flexible ureterorenoscopy: an in vitro comparison.

IntroductionSaline solution is the standard irrigant used during ureteroscopy. However, there is an opinion that water has better visual clarity. We aimed to compare the visual clarities of saline, water, and 5% mannitol as an irrigant during ureteroscopy.Material and methodsAn in vitro model consisting of an irrigant-filled container and a fiberoptic flexible ureteroscope was designed. A 1951 USAF Resolution Test Target and color checker within irrigants were used to evaluate the clarity of vision. The visual clarity was compared for 0.9% saline, distilled water and 5% mannitol solution with screen resolution and color contrast. The tests were repeated after adding human blood (2/400 ml) and contrast (20/400 ml) to the irrigants.ResultsThere was no significant difference in resolution values of three plain irrigants at a distance of 10 mm. However, when blood was added to the irrigants, a better resolution of 29.3% for water and 20.6% for mannitol was achieved compared to saline. At 20 mm of distance, it was observed that the difference was more pronounced in irrigants with blood. Water and mannitol had 55.6% and 37.1% better resolution than saline, respectively. In the color reproduction test, there was no significant difference in the three plain irrigants, however, water had better color contrast compared to the others.ConclusionsWater and 5% mannitol did not provide a significant image clarity advantage compared to saline. However, when blood was added to the irrigants, water provided significantly better visual clarity compared to saline. The use of water during various clinical scenarios in flexible ureteroscopy should be further investigated.

Comparison of a Single Use Digital Ureteroscope to a Fiberoptic Ureteroscope During Retrograde Renolithotripsy

Introduction: Ureterorenoscopy is a common procedure for treatment of stone disease. LithoVue is a relatively new entry in urologist armamentarium and offers digital image as well as single use nature when compared with traditional fiber-optic, reusable ureteroscopes. We aim to compare periprocedural outcomes for stone disease when using these two types of ureteroscopes. Patients and Methods: Baseline demographic data, perioperative( procedural time, surgical equipment, complication and stone-free rates) and postoperative(complication rate, length of stay) variables were recorded for two groups of patients: one managed with LithoVue and another with fiber-optic flexible ureteroscope. Chi-square and Fisher's exact test was used to compare qualitative data and unpaired t-test for continuous data, with a statistical significance set at a=0.05. Results: LithoVue was utilized in 40 and fiber-optic ureteroscope in 37 patients. The two groups were balanced regarding their baseline characteristics. Mean operative time for LithoVue cases was 49.36 ± 14.48 minutes and 62.46 ± 16.60 minutes for fiber-optic ureteroscope (p<0.001), while intraoperative stone-free rate for LithoVue was 70% and 43% for fiber-optic ureteroscope(p<0.005). This difference was also detected 24 hours postoperatively. Conclusions: Our study indicates that LithoVue can be used safely as an alternative for flexible fiber-optic ureteroscopes when managing patients with stone disease. These results should be confirmed with randomized trials.

The application of a single-use fiberoptic flexible ureteroscope for the management of upper urinary calculi.

To evaluate the clinical outcomes with a Chinese single-use fiberoptic flexible ureteroscope (YouCare Tech) from a prospective database. 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 < 2mm on a postoperative image study. 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 52min. The postoperative stone-free rate for the first 2weeks 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. 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.

PD35-09 COMPARISON OF A NOVEL SINGLE-USE FLEXIBLE URETEROSCOPE TO CURRENTLY EXISTING REUSABLE AND SINGLE-USE FLEXIBLE URETEROSCOPES

You have accessJournal of UrologyStone Disease: Surgical Therapy IV1 Apr 2017PD35-09 COMPARISON OF A NOVEL SINGLE-USE FLEXIBLE URETEROSCOPE TO CURRENTLY EXISTING REUSABLE AND SINGLE-USE FLEXIBLE URETEROSCOPES Daniel Wollin, Ruiyang Jiang, Daniela Radvak, Charles Scales, Michael Ferrandino, W Neal Simmons, Glenn Preminger, and Michael Lipkin Daniel WollinDaniel Wollin More articles by this author , Ruiyang JiangRuiyang Jiang More articles by this author , Daniela RadvakDaniela Radvak More articles by this author , Charles ScalesCharles Scales More articles by this author , Michael FerrandinoMichael Ferrandino More articles by this author , W Neal SimmonsW Neal Simmons More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1545AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Due to the high cost and limited durability associated with reusable ureteroscopes, single-use ureteroscopes have been gaining popularity in recent years. We aimed to directly compare the YouCare Single-Use fiberoptic flexible ureteroscope (YC-FR-A) to contemporary reusable/single-use flexible ureteroscopes in regards to optics, resolution, deflection, and irrigation flow. METHODS Four flexible ureteroscopes, YC-FR-A (YouCare Tech, China), LithoVue (Boston Scientific, USA), Flex-Xc (Karl Storz, Germany), and Cobra (Richard Wolf, Germany), were assessed in vitro for image resolution, distortion, color representation, and grayscale imaging. Ureteroscope deflection was tested with an empty channel followed by placement of a 200µm laser fiber and a 1.9F wire basket. Irrigation flow was measured using normal saline at a height of 100cm through an empty channel, channel with 200µm laser fiber, and channel with 1.9F basket. RESULTS The optical and functional characteristics of the four ureteroscopes are shown in Table 1. The YC-FR-A showed a resolution of 5.04 lines/mm and 4.3% image distortion. No substantial difference was demonstrated in color reproducibility or in the discernment of gray-scales between ureteroscopes. The YC-FR-A had an impressive one-way deflection of 349 degrees at baseline but lacks two-way deflection capability. In addition, there was a loss of deflection ability with any instrument in the working channel, with a loss of deflection ranging from 17.7 degrees to 30.3 degrees. With an empty channel, the YC-FR-A showed a maximum flow rate of 59 mL/min, which is the highest flow rate among the tested ureteroscopes. However, the flow rate decreased to 28.7 and 16.7 mL/min with laser fiber and basket in the working channel, respectively. CONCLUSIONS The YouCare Single-Use fiber-optic ureteroscope has comparable resolution to the Cobra fiberoptic ureteroscope but cannot match the two digital ureteroscopes tested. Although the one-way deflection and ergonomics of the YC-FR-A are not intuitive, this scope can be a viable alternative to the current reusable/single-use flexible ureteroscopes on the market; additionally, newer digital models in production may be more competitive. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e666 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Daniel Wollin More articles by this author Ruiyang Jiang More articles by this author Daniela Radvak More articles by this author Charles Scales More articles by this author Michael Ferrandino More articles by this author W Neal Simmons More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

MP33-18 FOURTH GENERATION FLEXIBLE URETEROSCOPES: A COMPARISON OF OPTICS, DEFLECTION AND FLOW

You have accessJournal of UrologyStone Disease: Surgical Therapy III1 Apr 2016MP33-18 FOURTH GENERATION FLEXIBLE URETEROSCOPES: A COMPARISON OF OPTICS, DEFLECTION AND FLOW Adam Kaplan, Daniela Radvak, Richard Shin, Annika Ackerman, Tony Chen, Fernando Cabrera, Joanne Dale, Michael Ferrandino, Charles Scales, Neal Simmons, Glenn Preminger, and Michael Lipkin Adam KaplanAdam Kaplan More articles by this author , Daniela RadvakDaniela Radvak More articles by this author , Richard ShinRichard Shin More articles by this author , Annika AckermanAnnika Ackerman More articles by this author , Tony ChenTony Chen More articles by this author , Fernando CabreraFernando Cabrera More articles by this author , Joanne DaleJoanne Dale More articles by this author , Michael FerrandinoMichael Ferrandino More articles by this author , Charles ScalesCharles Scales More articles by this author , Neal SimmonsNeal Simmons More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1375AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Flexible ureteroscopes remain in continual evolution, with improved optical characteristics and maneuverability with each generation. They now have smaller diameters than their predecessors and improved imaging capabilities, among other benefits. In this study, three ureteroscopes were directly compared with regards to optics, ureteroscope deflection and irrigation flow. METHODS Two digital flexible ureteroscopes including the Flex-Xc (Karl Storz, Germany) and URF-V2 (Olympus, Japan) and one fiberoptic flexible ureteroscope (URF-P6, Olympus, Japan) were assessed in vitro for image resolution, distortion, field of view, depth of field, grayscale imaging and color representation. Ureteroscope deflection was tested with an empty channel followed by placement of a 200 μm laser fiber, a 1.9F wire basket, a 2.0F Nanoelectric pulse lithotripsy (NPL) probe and a 2.4F NPL probe. Ureteroscope irrigation flow was measured using normal saline at 100 cm, with an empty channel followed by a 200 μm laser fiber, a 1.9F wire basket and a 2.0F NPL probe. RESULTS The optical characteristics of the three ureteroscopes are shown in Table 1. The digital platforms showed superior resolution and depth of field while the Fiberoptic platform had a larger field of view. No substantial difference was demonstrated in color reproducibility or grayscale discernment. Maximal deflection of each ureteroscope is shown in table 1. There was no significant difference in impact on deflection between the ureteroscopes by instruments in the working channel. With an empty channel, the flow rates of the URF-V2 and URF-P6 were identical and significantly lower than the Flex-Xc (p=0.001). The Flex-Xc maintained significantly faster flow with instruments in the channel than both the URF-V2 and URF-P6 (p=0.03). CONCLUSIONS The flexible ureteroscopes tested showed excellent optical, deflection and flow capabilities. The resolution of the digital ureteroscopes is superior to the fiberoptic scope, yet the field of view is limited. The Flex-Xc showed deflection comparable to the URF-P6, and improved flow rates over the URF-V2 and URF-P6. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e443-e444 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Adam Kaplan More articles by this author Daniela Radvak More articles by this author Richard Shin More articles by this author Annika Ackerman More articles by this author Tony Chen More articles by this author Fernando Cabrera More articles by this author Joanne Dale More articles by this author Michael Ferrandino More articles by this author Charles Scales More articles by this author Neal Simmons More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

The Digital Flexible Ureteroscope: In Vitro Assessment of Optical Characteristics

Recent advances in endoscope design have placed the charged coupled device chip on the tip of the endoscope. The image is instantly digitalized and converted into an electrical signal for transmission. Digital technology was first introduced into flexible cystoscopes/nephroscopes and subsequently into rigid and flexible ureteroscopes. Herein, we assess the image characteristics and advantages of a new generation of digital flexible ureteroscopes. The Olympus URF-V flexible digital ureteroscope and the Olympus URF-P3 fiberoptic ureteroscope were assessed in vitro for image resolution, distortion, color representation, grayscale imaging, field of view, and depth of field. The digital ureteroscope had a higher resolution at 3, 5, 10, and 20 mm (25.2 lines/mm vs. 8.0, 14.1 vs. 5.0, 6.3 vs. 2.8, and 3.2 vs. 1.3), respectively. Distortion with the digital flexible ureteroscope was lower, though not statistically significant. Color representation was better with the digital ureteroscope, whereas contrast evaluation was comparable between both scopes. The digital flexlible ureteroscope produced a 5.3 times larger image size compared with the standard fiberoptic flexible uretersocpe with a narrower field of view. The depth of field was limited by light and not the optic or the camera for both ureteroscopes. The development of digital flexible ureteroscopes represents a significant technological advance in urology. These devices offer significantly improved resolution and color reproduction as compared with traditional fiberoptic flexible ureteroscopes. Future clinical trials are warranted to ultimately determine the advantages of these innovative endoscopes.

Editorial Comment

This article tells us very much as well as very little about the current state of fiberoptic flexible ureteroscopes. The authors compared 4 commonly used, “next-generation” ureteroscopes in a prospective trial involving 175 patients at 3 institutions. Access sheaths were used in almost all cases, and the ureteroscopes were removed from the study after they required a major repair as a result of severe deficits in vision or maneuverability. Of the 12 brand-new, direct from the manufacturer ureteroscopes, 5 needed repair after ≤10 cases. The DUR-8E fared poorly with early failure at all 3 institutions after an average of 5.3 cases. However, in prior studies, the DUR-8E was superior in durability to its competitors, lasting an average of 14 and 42 uses before repair (Refs. 5 and 7 in the article, respectively). In those prior studies, the ureteroscopes being compared with the DUR-8E were earlier generations of models evaluated in this article. Although their forebears failed after an average of 4 and 8 uses, the Wolf and Olympus ureteroscopes in this study lasted 17 and 18 cases, respectively. While definitive conclusions cannot be made, it would seem that the quality of most ureteroscopes is improving. The poor performance of the DUR-8E in this study is not commensurate with prior investigations, and the reasons for this are not entirely clear. However, no statistically significant differences in durability or performance can be concluded from this study. In fact, the only significant difference was subjective visibility ratings, favoring the Wolf Viper. Thus, the direct ureteroscope comparisons tell us very little about which ureteroscope might be superior. Durability of the Next-generation Flexible Fiberoptic Ureteroscopes: A Randomized Prospective Multi-institutional Clinical TrialUrologyVol. 75Issue 3PreviewTo evaluate the durability of 4 next-generation flexible ureteroscopes in a randomized, multi-institutional, prospective study. Full-Text PDF ReplyUrologyVol. 75Issue 3PreviewWe appreciate each of the constructive editorial comments and concur that critical evaluations of the performance and durability of digital flexible ureteroscopes under a variety of sterilization protocols are warranted as the next step in quality assurance and improvement. The lack of statistical differences in durability in this study, though powered in a similar fashion to previous studies, confirms the observation that the playing field has been leveled. Though an alternate mode of transportation would be appealing, for now the flexible ureteroscope takes us places where other surgical instrumentation cannot. Full-Text PDF

Conventional Fiberoptic Flexible Ureteroscope Versus Fourth Generation Digital Flexible Ureteroscope: A Critical Comparison

Development of flexible renoureteroscopy had a significant impact on the diagnosis and management of upper urinary tract pathology. The aim of our study was to compare the performances of a fiberoptic flexible ureteroscope (FFU) with those of a digital flexible ureteroscope (DFU). We compared the maneuverability, visibility, and fragility of a Storz 11274AA FFU and of an Olympus URF-Vo DFU. In 44 diagnostic retrograde procedures (22 with FFU and 22 with DFU), the maneuverability and visibility were evaluated with a score ranging from 1 to 5. The success of the inferior calix approach, maximal deflection, irrigation flow, and the endoscopes' fatigability were also compared. FFU and DFU received mean scores of 3.64 vs 4.27 for maneuverability and 3.27 vs 4.68 for visibility. In four cases, acute infundibulopelvic angle and long infundibulum prevented the inferior calix approach with FFU. In two cases, the approach of the narrow infundibulum was impossible using DFU. The normal/pressure irrigation flow through FFU and DFU was 54/144 vs 60/150 mL/min with an empty working channel, decreasing to almost 0 mL/min with 3F instruments inserted. The maximal deflection loss of FFU and DFU ranged between 8% to 50.6% vs 0% to 21.1%, depending on the accessory instrument inserted through the working channel. After 22 procedures, the deflection loss was 10 degrees for the FFU and 0 degrees for the DFU. DFU proved to have superior maneuverability and visibility, which may translate into improved performances. The larger tip of the DFU may decrease its accessibility, especially in narrow segments of the upper urinary tract.

C73 Conventional fiberoptic flexible ureteroscope vs. 4th generation digital flexible ureteroscope: a critical comparison

C73 Conventional fiberoptic flexible ureteroscope vs. 4th generation digital flexible ureteroscope: a critical comparison