Improving flexible ureterorenoscope durability up to 100 procedures

The Predictive Factors for the Longer Survival of the Reusable Flexible Ureterorenoscopy

PURPOSE

The flexible ureterorenoscopy (FURS) is expensive and fragile equipment which easily break down during the surgery. f-URS have yet some problems with their durability that affect survival. One of the most important ways to increase the survival of a device is to improve its use in the right indications. We aimed to investigate whether the durability of the f-URS will be affected due to the volume and location of the stone and some anatomical features of the including infundibulopelvic angle (IPA), and location anomalies.

MATERIALS AND METHODS

The collected data from 705 patients' data including their age, sex, stone location, and stone volume, S-ReSC score, Hounsfield unit (HU) as stone density, IPA, BMI, and the usage time of f-URS using 10f-URS were included to study. Exp(B) values and confidence intervals (95% CIs) of parameters were calculated with COX regression and Roc curve analysis was also used to determine the cut-off value.

RESULTS

Renal malformation, DJstent use, previous ESL application, and UAS use did not affect contrary to expectations stone volume, HU, IPA, and S-ReSC score were among the factors statistically significant affecting the durability of the device. It was observed, Exp(B) values of the affecting factors to be 0.984, 0.268, 0.894, and 0.607, respectively. We found the most appropriate cutoff value for IPA as 41.25 degrees.

CONCLUSION

The mean stone volume broken by each of the subsequent f-URS may increase, while the mean operative time may decrease as time progresses. This result shows us the importance of mastery of the device, such as the deflection maneuver, and the correct use distance of the laser, which improves with the increase in user experience, and makes us interpret that the operation time is shortened with this self-confidence. Factors including stone volume, HU, IPA, S-ReSC score affect the durability of the f-URS device and the as well as manufacturing features.

Breakage Costs in Flexible Ureteroscopy: Digital vs. Fiberoptic Modalities

OBJECTIVE

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.

METHODS

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).

RESULTS

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).

CONCLUSION

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.

Repair Rate and Associated Costs of Reusable Flexible Ureteroscopes: A Systematic Review and Meta-analysis

Context

The refined mechanics of a flexible ureteroscope (fURS) are vulnerable to damage. Sending the fURS for repair is costly and has driven interest toward estimating the resources used for fURS repairs.

Objective

To systematically review available literature and to estimate the total weighted repair rate of an fURS and the average repair cost per ureteroscopy.

Evidence acquisition

A systematic review was conducted by searching the MEDLINE, Embase, Web of Science, and Cochrane Library databases. The average costs of all repairs identified in the included studies were extracted. A random-effect model was used to calculate the pooled total fURS repair rate. The total weighted repair rate and average cost per repair were multiplied to provide an average cost of repair per ureteroscopy procedure.

Evidence synthesis

We identified 18 studies that fulfilled the inclusion criteria, which included 411 repairs from 5900 investigated ureteroscopy procedures. The calculated weighted repair rate was 6.5% ± 0.745% (95% confidence interval: 5.0–7.9%; I² = 75.3%), equivalent to 15 ureteroscopy procedures before repair. The average cost per repair was 6808 USD; according to the weighted repair rate of 6.5%, this corresponds to an average repair cost of 441 USD per procedure. Egger’s regression test did not reveal a significant publication bias (p = 0.07).

Conclusions

This is the first meta-analysis to estimate the repair rate of the fURS used for ureteroscopy. Our analysis demonstrates a repair rate of 6.5%, equivalent to 15 ureteroscopy procedures between fURS repairs and a repair cost of 441 USD per procedure. Ureteroscopy practices should consider fURS breakage rates and repair costs to optimize the use of reusable versus disposable devices.

Patient summary

We reviewed available literature investigating the repair rate of a flexible ureteroscope (fURS). We found that fURSs are sent for repair after every 15 ureteroscopy procedures, corresponding to 441 USD per procedure in repair cost.

Advanced ureteroscopic techniques for the management of kidney stones

PURPOSE OF REVIEW

Recent years witnessed significant changes in the endourological management of renal tones because of the development of new, more advanced instruments. Retrograde intrarenal surgery (RIRS) has gained particular advantage from such technological progress and now tends to be considered the gold standard treatment for uncomplicated less than 20 mm renal stones. Using a step-by-step approach, this review aims to highlight current achievements but also unsolved problems in RIRS.

RECENT FINDINGS

Several technical details of RIRS, including preoperative stenting, use of ureteral access sheets, lithotripsy method, and renal drainage, remain open to discussion and linked to surgeon's preference. Moreover, there is a wide range of variation in efficacy and safety data, with major complications being episodic but often under-reported.

SUMMARY

RIRS has gained increased popularity among the urological community. This is certainly because of the continuous technological advancements, which have continuously improved the RIRS performance but also to the perception of ease and safety of this procedure when compared with the other available treatment modalities, particularly percutaneous nephrolitotomy. Indeed, the reported advances in RIRS technique have significantly improved the outcomes of this procedure but care should be taken not to underestimate its potential challenges.

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.

Handling and protecting your flexible ureteroscope: how to maximise scope usage

Flexible ureteroscopy is an important therapeutic and diagnostic procedure and has seen rapid rise in its utilisation in recent years. There have been numerous developments in flexible ureteroscope (fURS) technology but scope fragility, and the associated high maintenance costs, remains a concern. A comprehensive Medline search for related publications from the last 20 years was undertaken to identify common causes of fURS damage and ascertain practices to minimise this. Flexible ureteroscopy can be due to intraoperative causes (loss of the deflection mechanism, damage to the working channel due and fibreoptic bundle injury) and non-operative damage which occur during cleaning, sterilisation and handling of the fURS. The review summarises the available literature to help highlight common mechanisms of scope damage, and outlines evidence-based measures to reduce the risk of damage and maximise durability. Scope fragility remains a problem with significant associated cost implications. In a culture of rising fURS use and reducing re-imbursement for endourologists, prolonging the longevity of the fURS is imperative for maintaining profitability. There are simple and inexpensive practices which can be immediately adopted to maximise fURS use and reduce the need for repairs.

Let's Get to the Point: Comparing Insertion Characteristics and Scope Damage of Flat-Tip and Ball-Tip Holmium Laser Fibers

INTRODUCTION

A ball-tip holmium laser fiber (TracTip; Boston Scientific) has been developed to theoretically reduce damaging friction forces generated within a ureteroscope working channel. We compared the insertional forces and damage with a ureteroscope inner lining when inserting standard flat-tip and ball-tip laser fibers.

MATERIALS AND METHODS

A standard ureteroscope channel liner was placed in a 3D-printed plastic mold. Molds were created at four angles of deflection (30°, 45°, 90°, and 180°) with a 1 cm radius of curvature. New 200 μm ball-tip (TracTip; Boston Scientific) and 200 μm flat-tip (Flexiva; Boston Scientific) laser fibers were advanced through the liner using a stage controller. A strain gauge was used to measure force required for insertion. Each fiber was passed 600 times at each angle of deflection. The ureteroscope liner was changed every 150 passes. Leak testing was performed every 50 passes or when the insertional force increased significantly to assess damage to the liner.

RESULTS

At all deflection angles, the average insertional force was significantly lower with the ball-tip laser fibers compared with flat-tip laser fibers (p < 0.001). All trials with the ball-tip lasers were completed at each angle without any leaks. Two of four trials using flat-tip fibers at 45° deflection caused liner leaks (at 91 and 114 passes). At 90° deflection, all flat-tip trials caused liner leaks on first pass. The 180° trials could not physically be completed with the flat-tip laser fiber. Within the flat- and ball-tip groups, an increasing amount of force was needed to pass the fiber as the degree of deflection increased (p < 0.001).

CONCLUSIONS

The ball-tip holmium laser fiber can be safely passed through a deflected ureteroscope without causing liner perforation. The standard flat-tip fiber requires greater insertion force at all angles and can cause the ureteroscope liner to leak if it is deflected 45° or more.

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

OBJECTIVE

To evaluate the clinical outcomes with a Chinese single-use fiberoptic flexible ureteroscope (YouCare Tech) from a prospective database.

MATERIALS AND METHODS

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 < 2 mm on a postoperative image study.

RESULTS

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 52 min. The postoperative stone-free rate for the first 2 weeks 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.

CONCLUSION

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.

Single use and disposable flexible ureteroscopes

PURPOSE OF REVIEW

Flexible ureteroscopy has been widely developed in the last decade been nowadays one of the first line treatment options for urolithiasis and conservative management for upper tract urothelial tumors. Even though some unfavorable features of the reusable flexible scopes can limit the surgical procedure such as their availability, lack of sterilization or costly repairs. Disposable scopes have been developed with the intention of improving such problems.

RECENT FINDINGS

To our knowledge, seven devices have been developed. Of the scopes features, size, deflection, image quality and ergonomic handling have to be at least as good as reusable ones as they are expected to be noninferior. Three devices match all the features of reusable scopes, although only one has been properly studied.

SUMMARY

Not all the available disposable devices have been properly studied or compared with standard scopes. Although some devices are promising more studies are needed to proof their benefits.

In vitro investigations of propulsion during laser lithotripsy using video tracking

OBJECTIVES

Ureteroscopic laser lithotripsy is an important and widely used method for destroying ureter stones. It represents an alternative to ultrasonic and pneumatic lithotripsy techniques. Although these techniques have been thoroughly investigated, the influence of some physical parameters that may be relevant to further improve the treatment results is not fully understood. One crucial topic is the propulsive stone movement induced by the applied laser pulses. To simplify and speed up the optimization of laser parameters in this regard, a video tracking method was developed in connection with a vertical column setup that allows recording and subsequently analyzing the propulsive stone movement in dependence of different laser parameters in a particularly convenient and fast manner.

MATERIALS AND METHODS

Pulsed laser light was applied from below to a cubic BegoStone phantom loosely guided within a vertical column setup. The video tracking method uses an algorithm to determine the vertical stone position in each frame of the recorded scene. The time-dependence of the vertical stone position is characterized by an irregular series of peaks. By analyzing the slopes of the peaks in this signal it was possible to determine the mean upward stone velocity for a whole pulse train and to compare it for different laser settings. For a proof of principle of the video tracking method, a specific pulse energy setting (1 J/pulse) was used in combination with three different pulse durations: short pulse (0.3 ms), medium pulse (0.6 ms), and long pulse (1.0 ms). The three pulse durations were compared in terms of their influence on the propulsive stone movement in terms of upward velocity. Furthermore, the propulsions induced by two different pulse energy settings (0.8 J/pulse and 1.2 J/pulse) for a fixed pulse duration (0.3 ms) were compared. A pulse repetition rate of 10 Hz was chosen for all experiments, and for each laser setting, the experiment was repeated on 15 different freshly prepared stones. The latter set of experiments was compared with the results of previous propulsion measurements performed with a pendulum setup.

RESULTS

For a fixed pulse energy (1 J/pulse), the mean upward propulsion velocity increased (from 120.0 to 154.9 mm · s^-1 ) with decreasing pulse duration. For fixed pulse duration (0.3 ms), the mean upward propulsion velocity increased (from 91.9 to 123.3 mm · s^-1 ) with increasing pulse energy (0.8 J/pulse and 1.2 J/pulse). The latter result corresponds roughly to the one obtained with the pendulum setup (increase from 61 to 105 mm · s^-1 ). While the mean propulsion velocities for the two different pulse energies were found to differ significantly (P < 0.001) for the two experimental and analysis methods, the standard deviations of the measured mean propulsion velocities were considerably smaller in case of the vertical column method with video tracking (12% and 15% for n = 15 freshly prepared stones) than in case of the pendulum method (26% and 41% for n = 50 freshly prepared stones), in spite of the considerably smaller number of experiment repetitions ("sample size") in the first case.

CONCLUSION

The proposed vertical column method with video tracking appears advantageous compared to the pendulum method in terms of the statistical significance of the obtained results. This may partly be understood by the fact that the entire motion of the stones contributes to the data analysis, rather than just their maximum distance from the initial position. The key difference is, however, that the pendulum method involves only one single laser pulse in each experiment run, which renders this method rather tedious to perform. Furthermore, the video tracking method appears much better suited to model a clinical lithotripsy intervention that utilizes longer series of laser pulses at higher repetition rates. The proposed video tracking method can conveniently and quickly deliver results for a large number of laser pulses that can easily be averaged. An optimization of laser settings to achieve minimal propulsive stone movement should thus be more easily feasible with the video tracking method in connection with the vertical column setup. Lasers Surg. Med. 50:333-339, 2018. © 2017 Wiley Periodicals, Inc.

Single-use flexible ureteropyeloscopy: a systematic review

PURPOSE

Data assessing the effectiveness of single-use flexible ureteropyeloscopy (FURS) are limited. This study evaluates and compares single-use FURS with conventional reusable FURS.

METHODS

A systematic search using electronic databases (Pubmed and Embase) was performed for studies evaluating single-use FURS in the setting of urinary tract stone disease. Outcome measures included a comparative evaluation of their mechanical, optical and clinical outcomes.

RESULTS

Eleven studies on 466 patients met inclusion criteria. In vitro comparative data were available on three single-use flexible ureteropyeloscopes (LithoVue™, Polyscope™ and SemiFlex™) and clinical data were available on two (LithoVue™ and Polyscope™). The overall stone-free rate and complication rate associated with single-use FURS was 87 ± 15% and 9.3 ± 9%, respectively. There were no significant differences in procedure duration, stone size, stone clearance and complication rates when single-use FURS and reusable FURS were compared (duration: 73 ± 27 versus 74 ± 13 min, p = 0.99; stone size: 1.36 ± 0.2 versus 1.34 ± 0.18 cm, p = 0.93; stone-free rate: 77.8 ± 18 versus 68.5 ± 33%, p = 0.76; complication rate 15.3 ± 10.6 versus 15 ± 1.6%, p = 0.3).

CONCLUSIONS

Single-use FURS demonstrates comparable efficacy with reusable FURS in treating renal calculi. Further studies on clinical efficacy and cost are needed to determine whether single-use FURS will reliably replace its reusable counterpart.

Contract Costs Associated with Maintaining Flexible Ureteroscopes: A Single Center Experience

INTRODUCTION

We compared the cost of flexible ureteroscope processing and maintenance contracts offered by a scope manufacturer and a third-party company.

METHODS

Use and repairs of the Storz 11278AU1 Flex X2 Flexible Ureteroscope are prospectively recorded at our large, 371-bed, acute care hospital. A retrospective analysis of the processing of ureteroscopic instruments during a 3-year period (2011 to 2013) was completed. We compared the handling of ureteroscopes between 1 year under a third-party contractor (Integrated Medical Systems International, Inc. [IMS]) and 2 prior years under the manufacturer (KARL STORZ) contract.

RESULTS

From January 1, 2011 through October 1, 2012 our institution used the manufacturer for the processing of ureteroscopic instruments. From January 1, 2013 through December 9, 2013 our institution used the third-party contractor IMS for repairs. The number of procedures performed per repair/exchange during the manufacturer contract was 19.9 and the number of procedures performed per repair/exchange during the third-party contract was 11. The third-party contract resulted in a reduction of procedures performed per repair/exchange by 52%. Adjusted for inflation, the yearly cost of ureteroscope repairs was $125,715 during the manufacturer contract and $158,040 during the third-party contract. By analyzing the costs incurred in 2013, if our institution had maintained the manufacturer contract for all 3 years, the estimated repair cost would have resulted in a savings of $32,325.

CONCLUSIONS

Using the manufacturer repair contract is more cost-effective than using that of third-party companies.

Comprehensive Costs Associated with Fiberoptic and Digital Flexible Ureteroscopes at a High Volume Teaching Hospital

INTRODUCTION

Modern flexible ureteroscope ownership costs are considerable. Most prior estimates focus exclusively on repair costs, likely underestimating overall costs, including those of acquisition and reprocessing. Furthermore, to our knowledge no prior cost analyses focus on the latest generation digital flexible ureteroscope, which may differ due to unique purchase and repair prices. We sought to gain greater insight into the comprehensive costs associated with modern flexible ureteroscope use, particularly the difference between digital and fiberoptic models.

METHODS

Data on use and repair of fiberoptic Storz Flex-X2 and digital Flex-Xc flexible ureteroscopes from 2011 to 2015 were reviewed. List prices and repair costs were obtained from Storz. Per case reprocessing costs were estimated, accounting for disposables, reagents and labor. Maintenance costs were estimated by combining cost of repairs and reprocessing. Analyses were performed at list pricing and standard discount rates. Global flexible ureteroscope costs were calculated to account for the cost of acquisition, repair and maintenance of a new scope during its first 100 uses.

RESULTS

Global costs associated with digital flexible ureteroscope ownership were 1.3 to 1.4 times greater than fiberoptic on a per case basis ($1,008/$1,086 vs $715/$835). The majority of expenses went toward scope repairs (73% vs 71%), with instrument purchase (23% vs 24%) and reprocessing (4% vs 5%) being less costly. Repair rates were not significantly different between fiberoptic and digital devices (12.5 vs 11.5, p=0.757).

CONCLUSIONS

Expenditures associated with ownership of modern flexible ureteroscopes are considerable and driven primarily by the high cost of repairs. Digital instruments are more costly despite comparable rates of flexible ureteroscope damage.

First clinical evaluation of a new single-use flexible ureteroscope (LithoVue™): a European prospective multicentric feasibility study

INTRODUCTION

We evaluated a new digital single-use flexible ureteroscope, LithoVue™ with respect to deflection, image quality and maneuverability.

METHODS

A prospective cohort study was conducted in eight tertiary reference centers in Europe in December 2015 and January 2016. All consecutive patients included underwent flexible ureteroscopy and were 18 years or older. Deflection and image quality pre- and post-use and maneuverability were rated with a Likert scale.

RESULTS

A total of 40 procedures were performed (five per institution). The indication for FURS was treatment of renal stones in 92.5 % of the cases. Before LithoVue™ usage, the median measured upward and downward deflections were both 270°. Image quality was rated as "very good" in 65 % of cases and "good" in 30 %. Maneuverability was "very good" in 77.5 % and "good" in 17.5 %. At the final evaluation, median upward and downward deflections were both 270°. Image quality was still "very good" in 65 % of cases and "good" in 30 % with no significant difference compared with preoperative data (p = 1). Maneuverability was "very good" in 72.5 % and "good" in 17.5 %, with no significant difference compared with preoperative data (p = 0.92). Two LithoVue™ broke during surgery (5 %): one occurring in extreme deflection with acute infundibulopelvic angle and spontaneous loss of vision for the second one.

CONCLUSION

The LithoVue™ displayed good image quality, active deflection and maneuverability. Further evaluation of surgical outcomes and cost analysis will help to present the best utility of this single-use FURS in current practice.

Comparison of New Single-Use Digital Flexible Ureteroscope Versus Nondisposable Fiber Optic and Digital Ureteroscope in a Cadaveric Model

Purpose: To evaluate LithoVue, the new single-use digital flexible ureteroscope, in a human cadaveric model and compare it with a nondisposable fiber optic and digital flexible ureteroscopes.

Materials and Methods: LithoVue, a conventional fiber optic, and digital flexible ureteroscopes were each tested in four renal units of recently deceased female cadavers by three surgeons. The following parameters were analyzed: accessibility to the kidney and navigation of the entire collecting system with and without ureteral access sheath (UAS), lower pole access measuring the deflection of the ureteroscope with the working channel empty, and with inside two different baskets and laser fibers. A subjective evaluation of maneuverability and visibility was assessed by each surgeon at the end of every procedure.

Results: Kidney access into the Renal unit 1 was not possible without UAS for all ureteroscopes because of noncompliant ureter at the level of sacroiliac joint. The reusable digital ureteroscope was unable to reach one calix of the lower pole and one calix of the upper pole (Renal units 2 and 3) without UAS placement. Lower pole access with baskets and laser fibers was possible for each ureteroscope after UAS placement. No statistically significant differences were detected in angle deflection between ureteroscopes. The digital ureteroscope was preferred for visibility in all procedures: LithoVue for maneuverability in six procedures, fiber optic in five procedures, and the digital ureteroscope in one procedure.

Conclusions: LithoVue seems to be comparable with conventional ureteroscopes in terms of visibility and manipulation into the collecting system in fresh human cadavers. Further studies in humans are needed to determine the clinical value of this new instrument.

Modular flexible ureteroscopy and holmium laser lithotripsy for the treatment of renal and proximal ureteral calculi: A single-surgeon experience of 382 cases

To determine the safety and efficacy of modular flexible ureteroscopy and holmium laser lithotripsy for the treatment of renal and proximal ureteral calculi, a retrospective chart review of a single surgeon's 3-year modular flexible ureteroscopy experience was performed. All of the patients were treated with modular flexible ureteroscopy and holmium laser lithotripsy by a single surgeon. Stone-free status was defined as no fragments or a single fragment ≤4 mm in diameter at the 3-month follow-up. The procedure number, operative time, stone-free rates, repeat usage of the multilumen catheter, and perioperative complications were documented. The present study included 215 male patients and 167 female patients, with an average age of 48.5±13.7 years (range, 17-84 years). The mean stone size was 11.5±4.1 mm (range, 4-28 mm), and the mean total stone burden was 17.5±5.7 mm (range 15-46 mm). A total of 305 patients (79.8%) had a stone burden ≤20 mm, and 77 patients (20.2%) had a stone burden >20 mm. The mean number of primary procedures was 1.3±0.2 (range, 1-3). The stone-free rate following the first and the second procedure was 73.4 and 86.9%, respectively. The mean postoperative hospital stay was 3.1±1.2 days (range, 2-6 days). The highest clearance rates were observed for proximal ureteral stones (100%) and renal pelvic stones (88.7%), whereas the lowest clearance rates were observed for lower calyx stones (76.7%) and multiple calyx stones (77.8%). The higher the initial stone burden, the lower the postoperative stone-free rate (≤20 vs. >20 mm; 89.8 vs. 75.3%). The overall complication rate was 8.1%. The results of the present study suggest that modular flexible ureteroscopy with holmium laser lithotripsy may be considered the primary method for the treatment of renal and proximal ureteral calculi in select patients, due to its acceptable efficacy, low morbidity, and relatively low maintenance costs.

Comparing the Efficacy of a Multimodular Flexible Ureteroscope With Its Conventional Counterpart in the Management of Renal Stones

OBJECTIVE

To report our prospective comparison of clinical efficacy between multimodular flexible ureteroscope, PolyScope, and conventional flexible ureteroscope, both combined with holmium laser lithotripsy in managing renal stones <3 cm in diameter.

PATIENTS AND METHODS

Between February 2011 and July 2014, a total of 360 adult patients with renal stones were randomized in a single tertiary-care center trial. For 180 patients in each arm, flexible ureteroscopy and holmium laser lithotripsy were done with either PolyScope or Olympus URF P-5 as control. The primary end points were single-session stone fragmentation rate and stone-free rate. The secondary end points comprised operation time, complication rate, and hospital stay.

RESULTS

Demographic and preoperative parameters were comparable between 2 groups. For stones of different locations and sizes, single-session stone fragmentation rate of PolyScope was similar to that of URF P-5. However, for lower calyceal stones, URF P-5 was significantly better than PolyScope (82.0% vs 69.2%; P = .022). No statistically significant difference existed in single-session or overall stone-free rate, complication rate, and hospital stay. Mean operation time of PolyScope group was 92.6 ± 20.2 minutes, 9 minutes (10.8%) longer than that of URF P-5 group 83.3 ± 17.1 minutes (P < .01).

CONCLUSION

PolyScope demonstrates similar overall stone clearance rate to a conventional flexible ureteroscope in managing renal calculi <3 cm in diameter, but for lower pole stones, it is of inferior efficacy and it is more skillfully demanding, taking longer operation time.

[Flexible ureteroscope damages. Evaluation of university hospital service equipment]

OBJECTIVE

To evaluate predictors of flexible ureterorenoscopes breakage and damage of their optical beam.

MATERIALS AND METHODS

Retrospective survey, single center on 393 interventions with 4 flexible ureterorenoscopes between January 2009 and March 2013. We analyzed factors linked to patient, pathology and surgical technique.

RESULTS

We identified 21 major accidents, a breakage rate of 5.34% and 76 pixels losses in the maintenance of endoscopes and 10 during the procedure. The only statistically significant predictor of loss was the cumulative duration of operating time since the last repair (P=0.04, OR=1.001 [1-1001]). For lesions of the optical beam between the procedures, parameters appearing as significant were the ureterorenoscope model (P=0.01, OR=2.558, 95% CI [1229-5326]), the use of instruments by the working channel: the laser (P=0.02, OR=2.06, 95% CI [1109-3827]), or the use of endoluminal graspers (P=0.007, OR=0.467, 95% CI [0269-0809]). Intraoperatively, the number of open or laparoscopic surgery (P=0.007, OR=3.105, 95% CI [1364-7068]), duration of intervention (P=0.01, OR=1.023, 95% CI [1.006-1041]) and the cumulative duration of intervention (P=0.003, OR=1.001, 95% CI [1-1002]) appeared to be statistically significant.

CONCLUSION

The only predictor of loss of equipment under repair was the cumulative duration of operation time. It has not been demonstrated any difference between ureterorenoscopes. It was during the endoscopes disinfection that the majority of optical beam lesions take place.

Predictive factors for flexible ureterorenoscopy requirement after rigid ureterorenoscopy in cases with renal pelvic stones sized 1 to 2 cm

Purpose

To evaluate the outcomes of rigid ureterorenoscopy (URS) for renal pelvic stones (RPS) sized 1 to 2 cm and to determine the predictive factors for the requirement for flexible URS (F-URS) when rigid URS fails.

Materials and Methods

A total of 88 patients were included into the study. In 48 patients, the RPS were totally fragmented with rigid URS and F-URS was not required (group 1). In 40 patients, rigid URS was not able to access the renal pelvis or fragmentation of the stones was not completed owing to stone position or displacement and F-URS was utilized for retrograde intrarenal surgery (RIRS) (group 2). The predictive factors for F-URS requirement during RIRS for RPS were evaluated. Both groups were compared regarding age, height, sex, body mass index, stone size, stone opacity, hydronephrosis, and previous treatments.

Results

The mean patient age was 48.6±16.5 years and the mean follow-period was 39±11.5 weeks. The overall stone-free rate in the study population was 85% (75 patients). In groups 1 and 2, the overall stone-free rates were 83% (40 patients) and 87% (35 patients), respectively (p>0.05). The independent predictors of requirement for F-URS during RIRS were male gender, patient height, and higher degree of hydronephrosis.

Conclusions

Rigid URS can be utilized in selected patients for the fragmentation of RPS sized 1 to 2 cm with outcomes similar to that of F-URS. In case of failure of rigid URS, F-URS can be performed successfully in this group of patients.

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.

Improved durability of flex-Xc digital flexible ureteroscope: how long can you expect it to last?

OBJECTIVE

To retrospectively analyze a significant number of flexible ureterorenoscopic procedures performed with the Storz Flex-Xc model to evaluate its durability.

MATERIALS AND METHODS

Between May 2012 and May 2013, all the flexible ureteroscopic procedures performed with 3 Storz Flex-Xc flexible ureteroscopes were analyzed. Relocation of the lower pole stones was performed in all cases when possible. In the second and third series, the access sheath was retracted together with the flexible ureteroscope, thus preventing the damages, which its distal part may inflict on the flexed endoscope.

RESULTS

A total of 406 procedures were performed on 372 patients: first endoscope used on 96 procedures (90 patients), second one on 151 procedures (139 patients), and third one on 159 procedures (143 patients). Ureteral access sheath was used in 71.4% of the cases. The first endoscope was used for 67.1 hours, the second for 107.7 hours, and the third one for 107.2 hours. Major repairs were needed after significant damages of the outer coating (first endoscope) and severe deterioration of the deflecting mechanism (second and third endoscopes).

CONCLUSION

The digital Storz Flex-Xc seems to be a durable model of flexible ureteroscope. The use of ureteral access sheath and avoidance of overstressing the deflection mechanism by relocating lower pole stones seem to offer substantial advantages in prolonging the lifespan of these expensive instruments.

The cost analysis of flexible ureteroscopic lithotripsy in 302 cases

The objective of this study was to audit the cost of flexible ureterorenoscopic lithotripsy. The data for 302 consecutive flexible ureteroscopic lithotripsy (FURSL) procedure undertaken in our department for renal stone treatment were collected retrospectively. The costs associated with performing FURSL, including the cost of ancillary equipment were analyzed. This includes the cost of the initial purchase of the ureterorenoscopes and the holmium laser equipment. The cost of flexible ureterorenoscopy for each lithotripsy procedure (for a total of 302 FURSL) was $118. Additional cost of ancillary equipment including laser device, ureteral access sheath and stone retrival catheter were $156, $231 and $611, respectively. In this series, the costs of the ancillary equipment including laser exceeded the purchase and maintenance of the flexible ureteroscope. The cost of disposables rather than flexible ureteroscope itself should be considered in planning the budget.