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.

The effectiveness and safety of Sun tip-flexible ureterorenoscope for the management of kidney stones: A protocol for systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Kidney stone is one of the urinary system diseases with a high incidence. In this study, we will evaluate the effectiveness and safety of Sun tip-flexible ureterorenoscope treating patients with kidney stone. METHODS AND ANALYSIS: English and Chinese literature about Sun tip-flexible ureterorenoscope treatment for kidney stones published before October 31, 2020 will be systematic searched in PubMed, Embase, Web of Science, Cochrane Library, Open Grey, Clinicaltrials.gov, Chinese Clinical Trial Registry, WANFANG, VIP Chinese Science and Technology Journal Database, CNKI, Chinese biomedical document service system (SinoMed). Only randomized controlled trials (RCTs) of patients with kidney stones will be included. Literature screening, data extraction, and the assessment of risk of bias will be independently conducted by 2 reviewers, and the 3rd reviewer will be consulted if any different opinions existed. Systematic review and meta-analysis will be produced by RevMan 5.3 and Stata 14.0. This protocol reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) statement, and we will report the systematic review by following the PRISMA statement. RESULTS: The current study is a protocol for systematic review and meta-analysis without results, and data analysis will be carried out after the protocol. We will share our findings in the fourth quarter of 2021. CONCLUSION: This study will provide recommendations for the effectiveness and safety of Sun tip-flexible ureterorenoscope for patients with kidney stones (KS), which may help to guide clinician. ETHICS AND DISSEMINATION: Ethical approval is not required as the review is a secondary study based on published literature. The results of the study will be published in peer-reviewed publications and disseminated electronically or in print. PROTOCOL REGISTRATION NUMBER: INPLASY2020110099.

Flexible ureteroscopy: reuse? Or is single use the new direction?

PURPOSE OF REVIEW: Single-use flexible ureteroscopes (su-fURS) aim at overcoming the main limitations of conventional reusable ureteroscopes in terms of acquisition and maintenance costs, breakages, and reprocessing. However, little data exist to date regarding the superiority of su-fURS at this regard. We aimed to perform a systematic literature review on available su-fURS performance with a focus on clinical data for all articles in the last 10 years. RECENT FINDINGS: To date, more than 10 different su-fURS are available on the market, with different characteristics and performance. Some of these devices have top-level features, almost catching up with those observed in reusable flexible ureteroscopes. Clinical evidence is mainly available only for two models, LithoVue and Uscope PU3022, and to date it is not strong enough to support routine adoption and use of su-fURS, with a consequent lack of consensus of specific clinical indications. Cost-effectiveness analyses seem to indicate an economic disadvantage in the routine adoption of su-fURS. Environmental issues related to the use of su-fURS also remain to be inquired and addressed. SUMMARY: Since their introduction, su-fURS have gained widespread popularity. Despite their ability at addressing reusable ureteroscope limitations, high-cost and a substantial lack of evidence are still limiting their routine adoption.

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.

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.

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

ABSTRACT 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 financial cost-effective decision model to flexible ureteroscope acquisition. Conclusions The cost-effectiveness of a flexible 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.

Avoiding a Lemon: Performance Consistency of Single-Use Ureteroscopes.

INTRODUCTION AND OBJECTIVES: Single-use flexible ureteroscopes are increasingly popular because of high repair costs of reusable ureteroscopes. As new single-use ureteroscopes enter the market, the consistency of performance of these devices has been questioned. Our objective was to compare two single-use ureteroscopes: the Pusen PU3022a (Zhuhai Pusen) and the LithoVue (Boston Scientific) with emphasis on physical and optical performance consistency. METHODS: Ten LithoVue and 10 Pusen ureteroscopes were evaluated in never-used condition. The following parameters were recorded: maximal tip deflection with an empty working channel, 200 µm laser fiber, and 1.9F basket; image resolution at 10, 20, and 50 mm; and irrigation flow rate; all ureteroscopes were then fully deflected for 200 cycles. Maximum deflection was remeasured. Mean values for each parameter were compared. To examine within-manufacturer consistency, the variance was calculated and an F-test performed to evaluate for equivalence. RESULTS: Both ureteroscopes provided max deflection over 270°. The Pusen flexed to a greater degree than LithoVue. The Pusen lost more deflection with a laser fiber in the working channel. LithoVue had higher resolution at 10 mm, but the ureteroscopes were similar at 20 and 50 mm. Although the working channel diameter is identical, irrigation flow was higher with the Pusen. However, its working channel was 7 cm shorter than LithoVue. After 200 cycles of deflections, LithoVue had less deflection loss, although one ureteroscope was excluded from analysis because of mechanical failure. Variability was minimal and not significant between manufacturers at all measured parameters. CONCLUSIONS: LithoVue and the newer PU3022a have similar "out-of-the-box" performance characteristics and seem durable. These two single-use flexible ureteroscopes performed consistently regardless of the manufacturer.

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.

The "Body Mass Index" of Flexible Ureteroscopes.

OBJECTIVE: To assess the "body mass index" (BMI) (weight and length) of 12 flexible ureteroscopes (digital and fiber optic) along with the light cables and camera heads, to make the best use of our instruments. MATERIALS AND METHODS: Twelve different brand-new flexible ureteroscopes from four different manufacturers, along with eight camera heads and three light cables were evaluated. Each ureteroscope, camera head, and light cable was weighted; the total length of each ureteroscope, shaft, handle, flexible end-tip, and cable were all measured. RESULTS: According to our measurements (in grams [g]), the lightest ureteroscope was the LithoVue (277.5 g), while the heaviest was the URF-V2 (942.5 g). The lightest fiber optic endoscope was the Viper (309 g), while the heaviest was the Cobra (351.5 g). Taking into account the entirety of the endoscopes, the lightest ureteroscope was the Lithovue and the heaviest was the Wolf Cobra with the Wolf camera "3 CHIP HD KAMERA KOPF ENDOCAM LOGIC HD" (1474 g). The longest ureteroscope was the URF-P6 (101.6 cm) and the shortest was the LithoVue (95.5 cm); whereas the Viper and Cobra had the longest shaft (69 cm) and URF-V had the shortest shaft (67.2 cm). The URF-V2 had the longest flexible end-tip (7.6 cm), while the LithoVue had the shortest end-tip (5.7 cm) in both directions (up/down), while the URF-V had the shortest upward deflection (3.7 cm). CONCLUSIONS: Newer more versatile digital endoscopes were lighter than their traditional fiber optic counterparts in their entirety, with disposable endoscope having a clear advantage over other reusable ureteroscopes. Knowing the "BMI" of our flexible ureteroscopes is an important information that every endourologist should always take into consideration.

Evaluating the Ergonomics of Flexible Ureteroscopy.

INTRODUCTION: To date, the ergonomics of flexible ureteroscopy (URS) have not been well described. We performed a study to assess the biomechanical stresses on urologists performing URS and to investigate the effect of ureteroscope type on these parameters. METHODS: Electromyography (EMG) was used to quantify the activation level of muscle groups involved in URS. Surface EMG electrodes (Delsys, Boston, MA) were placed on the right and left thenar, flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), biceps, triceps, and deltoid. Three endoscopes were studied: single-use digital (Boston Scientific LithoVue), reusable digital (Karl Storz Flex-Xc), and reusable fiber-optic (Karl Storz Flex-X2). Each ureteroscope was used to perform a set sequence of navigation and procedural tasks in a training model. EMG data were processed and normalized to compare the maximum voluntary contractions between muscle groups. Cumulative muscular workload (CMW) and average muscular work per second (AWS) were used for comparative analysis. RESULTS: For navigational tasks, CMW and AWS were greatest for the ECU, followed in descending order by right and left thenar, FCU, biceps, deltoid, and triceps. For procedural tasks, CMW and AWS were greatest for the right thenar, followed in descending order by the left thenar, ECU, FCU, triceps, biceps, and deltoid. During navigational tasks, both LithoVue and Flex-Xc had lower CMWs for every muscle group than Flex-X2 (p < 0.05). LithoVue and Flex-Xc had similar AWS and both were lower than Flex-X2 for the right thenar, ECU, biceps, and deltoid activation (p < 0.05). During procedural tasks, both LithoVue and Flex-Xc had lower CMWs and AWS for right and left thenar, ECU, and biceps than Flex-X2 (p < 0.05). CONCLUSIONS: This study provides the first description of EMG-measured ergonomics of URS. Both the single-use and reusable digital ureteroscopes have similar profiles, and both have significantly better ergonomic metrics than the reusable fiber-optic ureteroscope.

Locked Deflection During Flexible Ureteroscopy: Incidence and Elucidation of the Mechanism of an Underreported Complication.

BACKGROUND AND PURPOSE: Flexible ureteroscopy (URS) is widely implemented with a well-defined safety profile and low complication rates. Although rare, locked deflection of a flexible ureteroscope in the upper tract is a potentially serious complication with poorly understood etiology and is likely underreported. MATERIALS AND METHODS: We attempted to capture all cases of locked deflection during URS by performing an anonymous, online computer survey targeting members of the Endourological Society. The Manufacturer and User Facility Device Experience (MAUDE) database and published literature were queried to find additional cases. The indication for URS, method of ureteroscope removal, patient outcomes, incident reporting, and explanations provided by the manufacturer or third party repair service were obtained whenever possible. RESULTS: In total, 10 cases of locked deflection during flexible URS were identified. Survey responses were obtained from 250/2424 (10.3%) endourologists polled. Locked deflection was noted by 8/250 (3.2%). The reported literature and MAUDE database identified one case each. Successful removal was noted in four using retrograde manipulation techniques while a percutaneous approach was used in three patients. Open surgery was needed in two cases because of resultant ureteral avulsion, and in one case, an open ureterotomy was needed for ureteroscope extraction. According to our survey, locked deflection was reported to the patient in 4/8 cases, the hospital in 3/8 cases, and the Food and Drug Administration (FDA) 0/8 cases. The two cases reported outside of our survey both notified the FDA. The minority of respondents (2/8), including our group, felt improper surgical technique was responsible for resultant locked deflection. Specifically, removal of a completely deflected ureteroscope through a stenotic infundibulum should be avoided. Rather, in such a situation, the ureteroscope should be straightened under fluoroscopy before being withdrawn. CONCLUSIONS: Locked deflection of a flexible ureteroscope is rare and underreported. Some cases are attributed to surgical technique, and awareness is crucial for avoidance of this complication.

Prospective evaluation of refurbished flexible ureteroscope durability seen in a large public tertiary care center with multiple surgeons.

OBJECTIVE: To evaluate the durability and cost of maintenance for outsourced, refurbished flexible ureteroscopes. MATERIALS AND METHODS: Ureteroscope usage and repair were prospectively recorded over a 365-day period at a large 836-bed public hospital. Cases were performed by 14 different urologists using either refurbished DUR-8 or DUR-8 Elite model ureteroscopes. Retrograde cases involving calculi, urothelial carcinoma, stricture, and diagnostic evaluations were included. Ureteroscope repairs were performed by a single outsourced repair vendor, not the original manufacturer. RESULTS: A total of 501 ureteroscopic cases involving 550 ureteroscope usages were performed over a 365-day period. Semirigid ureteroscopes were used for 281 (56.1%) cases and refurbished flexible ureteroscopes for 220 (43.9%). The reason for the ureteroscopy was calculi in 386 (77.0%) cases, urothelial carcinoma in 32 (6.4%), stricture in 36 (7.2%), and diagnostic in 47 (9.4%). No repairs were needed during this period for semirigid scopes. Ureteral access sheaths were used in 82 (37.7%) of the cases. A total of 32 instances of catastrophic breakage occurred. Each newly refurbished ureteroscope was used for an average of 6.9 times before incurring further damage requiring repair. CONCLUSION: Refurbished flexible ureteroscopes that have undergone comprehensive repair are extremely fragile in the setting of multiple surgeon users in a large public hospital that uses central processing for sterilization and storage. This poor durability results in significant maintenance, repair, and administrative inconvenience that should be considered along with the purchase price.

Evaluation of the pressure leak test in increasing the lifespan of flexible ureteroscopes.

INTRODUCTION: Flexible ureteroscopes are expensive and delicate instruments that are integral in the offering of a minimally invasive technique of diagnosis and treatment of urolithiasis. Published literature has identified the importance of early damage recognition in preventing frequent use of the scope that would lead to further damage and high repair and replacement costs. Our study was designed to examine the outcome of the pressure leak test on the condition of flexible ureteroscopes after every use and analysing the damage and costs of maintenance. PATIENTS AND METHODS: A prospective study was designed with two treatment groups. Group 1, 95 consecutive procedures (n = 95) of flexible ureterorenoscopy and laser fragmentation of renal calculi were performed with ACMI DUR 8, (a scope with no in-built leak test facility). This was compared against group 2, where 98 procedures of laser fragmentation of renal calculi (n = 98) were performed using Storz Flex X(2) Ureteroscopes (with a in-built leak test facility). All scopes in Group 2 were tested for pressure leak after every procedure and the outcome of the tests recorded. RESULTS: Both groups were comparable for grade of surgeon; stone location, size & number; access sheath usage and duration of lasering. In Group 1, there were seven scope damages resulting in repairs/replacement amounting to costs $46264.40 (7.1% damage). In Group 2, three scopes revealed a positive pressure leak test, implying damage with repair costs of $9952.80 (3.1% damage) (p < 0.05). Significant cost savings and reduction in downtime were made in Group 2. CONCLUSIONS: Pressure leak testing following flexible ureterorenoscopy helped to significantly control costs of maintenance and repair. Newer scopes should have a leak testing mechanism as it prevents further detrimental damage to the scope, build-up of repair costs are avoided and there is an increase in the longevity of these delicate instruments.

Improving the durability of digital flexible ureteroscopes.

OBJECTIVE: To present the damage to digital flexible ureteroscopes after 1 year of use in a tertiary stone center and our strategy to reduce the damage. MATERIALS AND METHODS: Data regarding all procedures performed with 3 new digital flexible ureteroscopes (Olympus URF-V) were collected. We examined the conditions under which the damage occurred and retrieved the manufacturer's repair reports. Two study groups were created. Group 1 included all the procedures performed before the introduction of a set of guidelines for safe use of the digital flexible ureteroscopes and a stepwise credentialing process for new surgeons. Group 2 included all the procedures performed thereafter. RESULTS: A total of 141 procedures were performed in 122 patients. Five events of damage occurred in the first study group and were related to working in maximum deflection. In the second group only 3 events occurred. The damage affected the angulation system, working channel, or body shaft. No damage occurred to the imaging system of any ureteroscope. The changes that were made after the first 5 months of use resulted in a significant prolongation of the number of uses before damage occurred for every ureteroscope (10.6 vs 21.6 uses before damage, P = .035). CONCLUSION: The optical system of the new digital ureteroscopes is very durable; however, the overall longevity depends on the correct handling of their use. By following the proposed guidelines for safe use and with monitored training of new users, these instruments can have a significantly longer lifespan.

Standardized ex vivo comparison of different upper urinary tract biopsy devices: impact on ureterorenoscopes and tissue quality.

OBJECTIVES: To evaluate the influence of different biopsy forcipes on the deflection, irrigant flow, and optical characteristics of flexible ureterorenoscopes and to assess tissue quality for histopathologic evaluation in an ex vivo setting. MATERIALS AND METHODS: The following five different biopsy forcipes were compared: Olympus (FB-56D-1; diameter 5Fr.), R. Wolf (829.601; 3Fr.), Karl Storz Medical (11275ZE; 3Fr.), Boston Scientific (Piranha; 505-160; 3 Fr.), and Cook BIGopsy (115CM; 2.4 Fr.). The devices were tested in 3 different ureterorenoscopes: Storz 11278 VU (Flex-X(2)), Storz 11278 V (Flex-X(C)), and Wolf Cobra (7326071/-6). Tissue samples were obtained from porcine upper urinary tracts. RESULTS: Baseline irrigation flow rates with empty channels were significantly higher in the Wolf Cobra than in Storz ureterorenoscopes (30.5 vs. 23 and 21 ml/min). The BIGopsy forceps allowed for higher flow rates in both Storz ureterorenoscopes (2.2 and 1.3, respectively) when compared to the other devices (0.5 and 0.6 ml/min). The Storz and Wolf biopsy forcipes resulted in the highest impairment of the deflection angle. In all 3 ureterorenoscopes, flow rates and deflection angle were least impaired by the BIGopsy. However, BIGopsy compromised the field of view (20 % reduction vs. 12 % by others). The largest sample of renal pelvis and ureter biopsies was obtained with BIGopsy and Storz(®) forcipes, respectively. The extent of artifacts and denuded urothelium were comparable in all samples. CONCLUSIONS: The various biopsy devices showed different impacts on irrigation flow, deflection, and field of view. The Cook BIGopsy best retains irrigation flow in single-channel flexible ureterorenoscopes and deflection. However, a smaller field of view may complicate handling and tissue acquisition.

Advances in ureteroscopy.

Recent innovations in imaging equipment and novel instrumentation have helped ureteroscopy evolve from a diagnostic to a therapeutic tool. In this review, the authors highlight several of the most recent advances in ureteroscopy that have helped allow unprecedented access, visualization, and treatment of upper urinary tract pathologic conditions.

Improving flexible ureterorenoscope durability up to 100 procedures.

BACKGROUND AND PURPOSE: Controversy exists in the literature regarding flexible ureterorenoscopy (F-URS) durability, with a variable expected number of uses from a new F-URS. In this study, a tertiary center experience with the use of two consecutive F-URS is reported and suggestions as to how to improve durability further are made. MATERIALS AND METHODS: All F-URS performed in the same tertiary care center between July 2009 and February 2011, with two new instruments Flex-X, were reviewed retrospectively. All renal pathology were included. Ureteral cases were excluded. A 9.5F semirigid ureteroscope was always used at the start for a ureteral optical predilation and to explore the upper urinary tract for possible lithotripsy/laser ablation/biopsy. The F-URS was introduced sequentially to explore the remaining calices. Data pertaining to the procedure were collected. The method of sterilization was complete immersion with Cidex®. RESULTS: The instruments were substituted after 113 and 102 procedures, respectively. The first F-URS was used for a total operative time of 79 hours and 10 minutes while the second one was used for 71 hours and 25 minutes (mean 75 hours and 15 min). Procedure duration was 15 to 175 minutes (mean 58 min). The flexible instruments were used for a mean of 42 minutes per procedure (range 13-153 min). The indications for F-URS were therapeutic in 75.4% and diagnostic in 22.8% of the cases. For lower pole calculi, the stone was relocated in 65.2% and managed with the nonflexed flexible instrument 90% of the time. The most common causes of damage of F-URS were: Deflection mechanism impairment, inner sheath damage, and fiberoptic bundle breaks. CONCLUSIONS: Increased durability of F-URS was from a variety of factors, a key element of which was the method of sterilization, while routine use of the semirigid instrument initially further contributed significantly to increase the number of F-URS procedures, saving overall costs.

Comparison of ureteroscopic procedures with rigid and semirigid ureteroscopes in pediatric population: does the caliber of instrument matter?

OBJECTIVES: To compare the results of two different ureteroscopes in pediatric ureteroscopy (URS) procedures. PATIENTS AND METHODS: Sixty-five consecutive URS procedures in pediatric population (39 males, 26 females) were retrospectively evaluated. The subjects were divided in two groups according to the type of ureteroscope used: Group 1 (n = 32, Wolf 8F) and group 2 (n = 33, ACMI 6.9F). All the procedures performed in both groups were statistically compared regarding patient age, gender, lateralization, complication rates, whether the procedure was diagnostic or therapeutic, and whether a guide-wire was used. Additionally, in cases with ureteral stones, stone clearance rate and the necessity of a stone extractor were also compared between the groups. All data were statistically analyzed using chi-square and t tests, where appropriate. A p value less than 0.05 was considered as significant. RESULTS: Mean age of the groups were comparable (9.44 +/- 4.3 and 8.67 +/- 3.9, p = 0.456). There was no statistically meaningful difference between the groups regarding patients' gender, lateralization rates, whether the procedure was diagnostic or therapeutic, the need for a guide-wire use, and complication rates (p > 0.05). In cases with ureteral stones, both groups exhibited statistically comparable results in stone clearance rates and the use of a stone extractor (p > 0.05). CONCLUSIONS: Data on this comparison demonstrated that both ureteroscopy devices in pediatric population can be used safely in URS procedures. Neither the diameter nor the rigidity is significantly affecting the outcomes and success rates

Effects of resectoscope loop manipulation.

BACKGROUND AND PURPOSE: Urologic resectoscope loops often are manipulated to reposition the angle. The effects of these maneuvers on the efficiency and functionality of the loop have never been tested. Our goal was to evaluate the changes in tensile strength, conductivity, and dispersion of cautery effect resulting from such manipulation. MATERIALS AND METHODS: Resectoscope loops manufactured by Karl Storz, Olympus, Boston Scientific, and ACMI were tested for tensile strength and unevenness of cautery effect before and after one manipulation from an angel of 15 degrees posterior to 15 degrees anterior deviation. RESULTS: Prior to manipulation, the loops demonstrated a tensile strength of approximately 40 lb to failure. After one manipulation, the tensile strength was reduced by 90.1% (P < 0.001), with 46.7% of the loops failing to meet minimum industry standards. Manipulation of the loops increased the resistance to current flow within the wire. Microscopic evaluation showed longitudinal fracture lines at the manipulated sites. CONCLUSION: Physician-manipulated resectoscope loop angles have a dramatic effect on the strength of the loop as well as the dispersion of energy. A bend of 30 degrees results in 46.7% of the loops failing to meet minimum tensile-strength standards and alters the effectiveness and dispersion of electrical current. Infrared photography confirms the defect to be generated at the point of manipulation, thereby reducing the anticipated capabilities at a constant setting of the loop energizer. Ultimately, the quality of surgical resection suffers from even one manipulation of a resectoscope loop.