Experts' recommendations in laser use for the treatment of urolithiasis: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training-Research in Urological Surgery and Technology (T.R.U.S.T.)-Group

PURPOSE

To identify laser lithotripsy settings used by experts for specific clinical scenarios and to identify preventive measures to reduce complications.

METHODS

After literature research to identify relevant questions, a survey was conducted and sent to laser experts. Participants were asked for preferred laser settings during specific clinical lithotripsy scenarios. Different settings were compared for the reported laser types, and common settings and preventive measures were identified.

RESULTS

Twenty-six laser experts fully returned the survey. Holmium-yttrium-aluminum-garnet (Ho:YAG) was the primary laser used (88%), followed by thulium fiber laser (TFL) (42%) and pulsed thulium-yttrium-aluminum-garnet (Tm:YAG) (23%). For most scenarios, we could not identify relevant differences among laser settings. However, the laser power was significantly different for middle-ureteral (p = 0.027), pelvic (p = 0.047), and lower pole stone (p = 0.018) lithotripsy. Fragmentation or a combined fragmentation with dusting was more common for Ho:YAG and pulsed Tm:YAG lasers, whereas dusting or a combination of dusting and fragmentation was more common for TFL lasers. Experts prefer long pulse modes for Ho:YAG lasers to short pulse modes for TFL lasers. Thermal injury due to temperature development during lithotripsy is seriously considered by experts, with preventive measures applied routinely.

CONCLUSIONS

Laser settings do not vary significantly between commonly used lasers for lithotripsy. Lithotripsy techniques and settings mainly depend on the generated laser pulse's and generator settings' physical characteristics. Preventive measures such as maximum power limits, intermittent laser activation, and ureteral access sheaths are commonly used by experts to decrease thermal injury-caused complications.

Experts' recommendations in laser use for the treatment of upper tract urothelial carcinoma: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training Research in Urological Surgery and Technology (T.R.U.S.T.) group

PURPOSE

To highlight and compare experts' laser settings during endoscopic laser treatment of upper tract urothelial carcinoma (UTUC), to identify measures to reduce complications, and to propose guidance for endourologists.

METHODS

Following a focused literature search to identify relevant questions, a survey was sent to laser experts. We asked participants for typical settings during specific scenarios (ureteroscopy (URS), retrograde intrarenal surgery (RIRS), and percutaneous treatment). These settings were compared among the reported laser types to find common settings and limits. Additionally, we identified preventive measures commonly applied during surgery.

RESULTS

Twenty experts completed the survey, needing a mean time of 12.7 min. Overall, most common laser type was Holmium-Yttrium-Aluminum-Garnet (Ho:YAG) (70%, 14/20) followed by Thulium fiber laser (TFL) (45%, 9/20), pulsed Thulium-Yttrium-Aluminum-Garnet (Tm:YAG) (3/20, 15%), and continuous wave (cw)Tm:YAG (1/20, 5%). Pulse energy for the treatment of distal ureteral tumors was significantly different with median settings of 0.9 J, 1 J and 0.45 J for Ho:YAG, TFL and pulsed Tm:YAG, respectively (p = 0.048). During URS and RIRS, pulse shapes were significantly different, with Ho:YAG being used in long pulse and TFL in short pulse mode (all p < 0.05). We did not find further disparities.

CONCLUSION

Ho:YAG is used by most experts, while TFL is the most promising alternative. Laser settings largely do not vary significantly. However, further research with novel lasers is necessary to define the optimal approach. With the recent introduction of small caliber and more flexible scopes, minimal-invasive UTUC treatment is further undergoing an extension of applicability in appropriately selected patients.

Practices and utility of imaging among urological communities for urolithiasis, observations, and inferences from a targeted survey

To evaluate the general practice among urologists about the use of various radiological imaging and measurement tools, and to compare the different preferences in radiological evaluations between Turkish and European urologists. Our study was designed as a survey study. The survey comprised 22 questions which evaluated the epidemiological information, caseload of participants, general preferences of participants on CT image slice thickness, basic radiologic workup routines prior to surgery, use of special tools and measurements on CT. Data collection was conducted with both an online poll and printed copies. A total of 222 urologists from 23 different countries responded to the survey. The most performed endourologic surgery was semi-rigid URS which was performed more than 25 times/year by 90.1% (n = 200) of the participants. Although PCNL was performed more commonly by Turkish urologists (39.7%) compared to their European (17.3%) colleagues (p < 0.001), it was still the least often performed endourological surgery among all participants (31.5%). The stone size evaluation was the most performed measurement performed by the participants. Although the group of surgeons used size measurement tools, there were differences between the two groups. Turkish urologists used size measurement before PCNL (85.7%) as opposed to European urologists who used it mostly before URS (91.4%). Non-contrast CT images for urolithiasis are mainly evaluated by urologists themselves and a considerable number of urologists do not use additional measurement tools in evaluating CT images. Although there are similarities in the knowledge of various radiological tools, there are distinct regional differences.

Ablation rates with Holmium:YAG and Thulium Fiber Laser: Influence of the stone phantom homogeneity. An in vitro study

OBJECTIVES

The lithotripsy efficiency (LE) in vitro study requires artificial or human stone samples (AS, HS). With the development of dusting lithotripsy, less ex vivo HS are available. We aimed to compare Thulium Fiber Laser (TFL) and Holmium:YAG (Ho:YAG)'s LE and define the most accurate LE parameter.

METHODS

Hard and soft homogenous- and heterogenous-AS (Ho-AS, He-AS) were made to reproduce calcium-oxalate monohydrate and uric acid stones, respectively by a rapid or slow brewing of BegostonePlus (Bego) and distilled water. One hundred and fifty and 272μm-laser fibers, connected to 50W-TFL and 30W-HoYAG generators, compared three settings for TFL (FD: 0.15J/100Hz; D: 0.5J/30Hz; Fr: 1J/15Hz) and two for Ho:YAG (D-Fr). An experimental setup consisted in immerged 10mm cubic stone phantoms with a 20 seconds' lasing spiral, in contact mode, repeated four times. Stones were dried, weighted and μ-scanned (ablation weight and volume [AW and AV]).

RESULTS

With He-AS, dusting AV were four- and three-fold higher with TFL compared to Ho:YAG against hard and soft (P<0.05). In fragmentation, AV were two-fold higher with TFL compared to Ho:YAG against hard (P<0.05) and soft (P<0.05). Experiments with Ho-AS were associated with non-significant differences when comparing TFL-150μm and TFL-272μm. The ablation weight-volume correlation coefficients was higher with Ho-AS than with He-AS (P<0.0001), and with hard than soft AS. If the LE can be estimated by the AW with hard AS, this approximation is not consistent for soft AS.

CONCLUSION

TFL presented higher ablation rates than Ho:YAG, significant with He-AS. If the AW is acceptable and less expensive for hard Ho-AS, AV are more accurate for He-AS, which are suggested to imitate closely HS.

How reliable is endoscopic stone recognition? A comparison between visual stone identification and formal stone analysis

OBJECTIVE

To assess the diagnostic accuracy and intra-observer agreement of endoscopic stone recognition compared with formal stone analysis.

INTRODUCTION

Stone analysis is a corner stone in the prevention of stone recurrence. Although X-ray diffraction and infrared spectroscopy are the recommended techniques for reliable formal stone analysis, this is not always possible, and the process takes time and is costly. Endoscopic stone recognition could be an alternative as it would give immediate information on stone composition.

MATERIAL AND METHODS

Fifteen endourologists predicted stone composition based on 100 videos from ureterorenoscopy. Diagnostic accuracy was evaluated by comparing the prediction from visual assessment with stone analysis by X-ray diffraction. After 30 days, the videos were reviewed again in a random order to assess intra-observer agreement.

RESULTS

The median diagnostic accuracy for calcium oxalate monohydrate was of 54% in questionnaire 1 (Q1) and 59% in questionnaire 2 (Q2), whereas calcium oxalate dihydrate had a median diagnostic accuracy of 75% in Q1 and 50% in Q2. The diagnostic accuracy for calcium hydroxyphosphate was 10% in Q1 and 13% in Q2. The median diagnostic accuracy for calcium hydrogen phosphate dihydrate and calcium magnesium phosphate was 0% in both questionnaires. The median diagnostic accuracy for magnesium ammonium phosphate was in 20% in Q1 and 40% in Q2. The median diagnostic accuracy for uric acid was 22% in both questionnaires. Finally, there was a diagnostic accuracy of 60% in Q1 and 80% in Q2 for cystine. The intra-observer agreement ranged between 45-72%.

CONCLUSION

Diagnostic accuracy of endoscopic stone recognition is limited and intra-observer agreement is below the threshold of acceptable agreement.

Efficacy and safety of the EMS Swiss LithoClast® Trilogy for PCNL: results of the European multicentre prospective study on behalf of European Section of UroTechnology

Purpose

PCNL requires a lithotrite to efficiently break stones, and some devices include active suction to remove the fragments. We set out to determine the efficacy and safety of the Swiss LithoClast® Trilogy, in a prospective European multicentre evaluation and compared it to published stone clearance rates for Trilogy based on surface area (68.9 mm²/min) and using the 3D calculated stone volume (526.7 mm³/min).

Methods

Ten European centres participated in this prospective non-randomized study of Trilogy for PCNL. Objective measures of stone clearance rate, device malfunction, complications and stone-free rates were assessed. Each surgeon subjectively evaluated ergonomic and device effectiveness, on a 1–10 scale (10 = extremely ergonomic/effective) and compared to their usual lithotrite on a 1–10 scale (10 = extremely effective).

Results

One hundred and fifty seven PCNLs using Trilogy were included (53% male, 47% female; mean age 55 years, range 13–84 years). Mean stone clearance rate was 65.55 mm²/min or 945 mm³/min based on calculated 3D volume. Stone-free rate on fluoroscopy screening at the end of the procedure was 83%. Feedback for suction effectiveness was 9.0 with 9.1 for combination and 9.0 for overall effectiveness compared to lithotrite used previously. Ergonomic score was 8.1, the least satisfactory element. Complications included 13 (8.2%) Clavien–Dindo Grade II and 2 (1.3%) Grade III. Probe breakage was seen in 9 (5.7%), none required using a different lithotrite.

Conclusions

We have demonstrated that Trilogy is highly effective at stone removal. From a user perspective, the device was perceived by surgeons to be highly effective overall and compared to the most commonly used previous lithotrite, with an excellent safety profile.

A call for HoLEP: AEEP for mega-prostates (≥ 200 cc)

PURPOSE

To evaluate the efficiency and efficacy of HoLEP, and methods of tissue retrieval, in patients with prostate volume (PV) ≥ 200 cc (Group 1) and to compare these to patients with PV 80-199 cc (Group 2).

METHODS

A database of all cases performed under the care of two surgeons at a tertiary HoLEP centre was reviewed.

RESULTS

157 patients with PV ≥ 200 cc were compared to 157 of the most recent consecutive cases with PV 80-199 cc. Median (IQR) enucleation efficiency was greater in Group 1 [2.8 g/min (2.2-3.5)] than Group 2 [2.1 g/min (1.6-2.5), p < 0.001]. Morcellation efficiency did not differ significantly. Cystotomy was required for tissue retrieval in Group 1 only (5.7%). Decrease in serum haemoglobin (Hb) was greater in Group 1 (19 g/l (30-8) vs 12 (18-3.5), p < 0.001) with a transfusion rate of 4.5% vs 1.3%, respectively (p = 0.104). Length of stay was longer in Group 1 than Group 2 (1 day (1-2) vs 1 (1-1), p < 0.001). There were no significant differences between groups in: time to and success of first trial without catheter, pre- and post-operative IPSS, Qmax and PVR, and 3 month catheter-free and urinary incontinence rates.

CONCLUSION

HoLEP outcomes are largely PV-independent even when PV is ≥ 200 cc, although length of stay and reduction in Hb are greater in this group. Alternatives to pure morcellation, such as cystotomy and resection of nodules, are more likely to be necessary with PV ≥ 200 cc.

Percutaneous Cystolitholapaxy Using the LithoClast Trilogy for Multiple Bladder Stones

Background: Multiple large bladder calculi are traditionally managed through open cystolithotomy or transurethrally in patients who have an open bladder neck. Open procedures are technically challenging in patients who may have had multiple previous open surgeries, and may be associated with significant morbidity in patients with a high comorbid burden. Therefore, a percutaneous approach to such stones has been used especially when there is a closed bladder neck, and has been shown to be effective. There are a number of available devices for breaking stones in these approaches, the newest of which is the LithoClast Trilogy™ (EMS, Nyon, Switzerland) device, a probe that provides ultrasonic and mechanical calculi fragmentation and suction in a single instrument. Case Presentation: We describe the first reported case of percutaneous cystolitholapaxy using the LithoClast Trilogy device in a 41-year-old woman with spina bifida, and multiple large bladder calculi with a history of ileocystoplasty and Mitrofanoff formation, and a bladder neck closure for neuropathic bladder. The calculi measured 31 and 25 mm, and had a volume of 19.6 and 7.9 cm³ and average HU of 408 and 462, respectively. The calculi were composed of 37% calcium phosphate and 63% magnesium ammonium phosphate. Conclusion: We demonstrate that this approach can be used as a viable alternative to open surgery, which is of particular importance for complex patients who have undergone multiple previous open operations, and who may have a high comorbid burden.

Reusable flexible ureterorenoscopes are more cost-effective than single-use scopes: results of a systematic review from PETRA Uro-group

Clinical data suggest an equipoise between single-use (disposable) and reusable flexible ureterorenoscope (fURS) in terms of scope characteristics, manipulation, view and clinical outcomes. The procedural cost of reusable fURS is dependent on the initial and repair cost, maintenance and scope sterilization and on the number of procedures performed/repair. We conducted a systematic review on the procedural cost ($) of fURS based on the individual authors reported data on the number of procedures performed before repair and to see if it is a feasible option compared to single use fURS. A systematic review carried out in a Cochrane style and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist using Medline, Scopus, CINAHL, EMBASE and Cochrane library for all English language articles. All papers on fURS cost analysis were searched from 2000-2018 (19 years), which mentioned the cost of fURS based on the number of procedures performed and the repairs needed (procedure/repair) as reported by the individual authors. Six studies reported on both the number of procedures performed with number of repairs needed and the cost calculated/procedure in the given time period. The number of uses/repair in various studies varied between 8-29 procedures and the cost per procedure varied between $120-1,212/procedure. A significant trend was observed between the decreasing cost of repair with the number of usages. With studies reporting on a minimum of 20 cases/repair the mean cost was around $200/procedure. This is contrast to the disposable scopes such as Lithovue ($1,500-2,000/usage) and Pusen ($700/usage). The cost of reusable fURS is low in centres performing a high volume of procedures. Similarly, when a reasonable volume of procedures is performed before scope repair, the cost is lower than the disposable scopes. Although, the disposable and reusable scopes seem to be comparable in terms of their performance, this review proves that reusable fURS are still more cost effective than disposable scopes.

Pictorial review of tips and tricks for ureteroscopy and stone treatment: an essential guide for urologists from PETRA research consortium

With an increase in the number of ureteroscopy (URS) procedures, URS is now performed more widely and is becoming a standard procedure for all urologists. There is also a rise in the complexity of these procedures and URS is now offered for treatment of stones as well as for diagnosis and treatment of urothelial tumours. We wanted to provide a 'pictorial review' of the 'tips and tricks' of URS, as the finer and technical details are often easier to understand and remember with images rather than through textual explanations.

The industrial revolution for the management of benign prostate obstruction: worldwide publication trends for surgical and medical therapies over the past two decades

INTRODUCTION

Research for management of benign prostate obstruction (BPO) for adult males remains a cornerstone of urology research. This landscape has witnessed the rise and fall of multiple therapies, both surgical and medical. Our aim was to formally evaluate the publication trends for these interventions over the past 20 years.

MATERIAL AND METHODS

A systematic search was performed in a Cochrane style. Data was analysed using the independent t-test and Pearson's correlation coefficient (SPSS version 24). To observe changes in trends more effectively, data was sub-divided into two time periods: 1997 to 2006 and 2007 to 2016.

RESULTS

Over the past 20 years, 4236 papers have been published concerning for BPO (surgical, n = 2177 and medical, n = 2059). For surgical treatments, these included articles on monopolar transurethral resection of prostate (TURP) (n = 340), bipolar TURP (n = 260), HoLEP (n = 293) and Greenlight laser (n = 395). For medical therapies, these included alpha blockers (848), 5-alpha reductase inhibitors (n = 618) and PDE5I (n = 91). Between the two time periods the change was +18.8% (p = 0.108) for monopolar TURP, +497.1% (<0.001) for bipolar TURP, -54.5% (p <0.001 for prostatic stents and -81.9% (p <0.001) for transurethral microwave therapy (TUMT). There was over 290% rise in number of publications related to BPO laser surgery (p <0.001). For medical interventions, the change was +11.5% (p = 0.397) for alpha blockers, -1.9% (p = 0.867), +49.0%( 0.122) for phytotherapy, +2075% (p <0.001) for PDEI and +2375.0% (p <0.001) for combined alpha blocker and anti-muscarinics.

CONCLUSIONS

Interventions for BPO have undergone a high volume of research. In particular, minimally invasive laser surgeries and combined medical therapies have seen significant expansion.

Outcomes and Long-term Follow-up of Patients with Cystine Stones: a Systematic Review

PURPOSE OF REVIEW

Cystine stone patients can be difficult to manage with frequent recurrences. We performed a systematic review with a view to assessing interventions, compliance and their long-term outcomes.

RECENT FINDINGS

Ten retrospective observational studies (253 patients) assessed the outcomes and long-term follow-up of cystine stone patients. The mean length of follow-up was 9.6 years (range 3.5-21.8 years). The overall mean number of surgical procedures/patient was 5.7 (range 2-9.8/patient) with the overall mean number of surgical procedures/patient/year at 0.59 (range 0.22-1.32/patient/year). While open surgery has decreased over the last decade and PCNL has been stable, there seems to be a rise of RIRS during this period. Patients with cystine stones need periodic interventions for stone recurrences despite medical management, with limited data showing the impact on renal function. While the management is individualised, wide variability exists with often poor and incomplete patient data.

The new Avicenna Roboflex: How does the irrigation system work? Results from an in vitro experiment

Introduction: Since 2012 Elmed has been working on a robot specifically designed for flexible ureteroscopy. After the first version of Avicenna Roboflex, a second version was developed in 2015, with significant changes especially in the irrigation system. We consider mandatory for the endourologist that works with the Avicenna Roboflex be aware of the functioning of the irrigation system. Materials and Methods: We connected a container to the pump’s irrigation system and measured the quantity of saline per second delivered by each speed setting, with/without the flush in five different modalities: pump on its own, pump with ureteroscope, with two laser fibers, with 1.9 Fr basket, and with a Terumo guidewire. Results: The highest mean flow-rates were observed in the 200- micrometer laser fiber, after the pump on its own. Median flowrates for all speed settings were significantly higher for the pump on its own than for the URS in both flushed and nonflushed modes (p = 0.045, p = 0.039 respectively). There was no statistically significant difference in median flow-rates between the guide wire and basket in all of the speed settings (p = 0.932 and p = 0.977). For both laser fibers there was no statistically significant difference between the median flow rate on both nonflush and flush modes. (p = 0.590 & p = 0.590). There was a linear correlation between the speed setting and the increase measured with the flush-option for pump only measurements (r = 0.602, p = 0.038). There was no statistically significant difference between laser fibers and the pump on its own on the increase of flow rate with flush mode. (p = 0.443 for the 272- micrometer fiber and p = 0.219 for the 200-micrometer fiber). Conclusion: The irrigation system of the new Avicenna Roboflex is optimized compared to the previous version. However other more complex studies concerning the live flow/pressure relationship are needed before firm conclusions can be made.

Ureteroscopy in pregnant women with complicated colic pain: Is there any risk of premature labor?

OBJECTIVE

Clinical presentation of ureteral stones during pregnancy is generally with renal colic pain. The aim of this study is to present our experience in the management of renal colic during pregnancy in emergency settings.

MATERIALS AND METHODS

208 pregnant patients who presented to emergency department with renal colic pain and underwent ureteroscopy (URS) due to failed conservative therapy were enrolled in the study. Urinary tract stones were diagnosed either with ultrasound (US) examination or during URS. Laser lithotripsy and double J (DJ) stent placement were routinely done in all patients with ureteral stones. The incidence of infective complications and premature uterine contractions (PUC) due to URS were compared.

RESULTS

No stone was identified in 36.1% (n = 75) of patients with using US and diagnostic URS. Of the remaining 133 patients, 30 (22.6%) had no stone at US but stones were diagnosed during diagnostic URS. The type of anesthesia had no significant effect on PUC. An increased risk of sepsis and PUC was found in patients with fever at the initial presentation. Interestingly, PUC was more frequent in patients with lower serum magnesium levels. There was a significant correlation with time delay until the intervention and the risk of urosepsis and PUC, individually.

CONCLUSIONS

Ureteroscopy is a safe option for evaluation of pregnant patients with unresolved renal colic. According to the current findings, timing of the operation is the most important factor affecting the septic risks and abortion threat. Surgical intervention with URS must be planned as soon as possible.

In Vitro Comparison of Maximum Pressure Developed by Irrigation Systems in a Kidney Model

Purpose: To evaluate in vitro the maximum pressure generated in an artificial kidney model when people of different levels of strengths used various irrigation systems. Materials and Methods: Fifteen people were enrolled and divided into three groups based on their strengths. Individual strength was evaluated according to the maximum pressure each participant was able to achieve using an Encore™ Inflator. The irrigation systems evaluated were as follows: T-Flow™ Dual Port, Hiline™, continuous flow single action pumping system (SAPS™) with the system close and open, Irri-flo II™, a simple 60-mL syringe, and Peditrol™. Each irrigation system was connected to URF-V2 ureteroscope, which was inserted into an artificial kidney model. Each participant was asked to produce the maximum pressure possible with every irrigation device. Pressure was measured with the working channel (WC) empty, with a laser fiber, and a basket inside. Results: The highest pressure was achieved with the 60 mL-syringe system and the lowest with SAPS continuous version system (with continuous irrigation open), compared to the other irrigation devices (p < 0.0001). Irrespective of the irrigation system, there was a significant difference in the pressure between the WC empty and when occupied with the laser fiber or the basket inside it (p < 0.0001). The stratification between the groups showed that the most powerful group could produce the highest pressure in the kidney model with all the irrigation devices in almost any situation. The exception to this was the T-Flow system, which was the only device where no statistical differences were detected among these groups. Conclusion: The use of irrigation systems can often generate excessive pressure in an artificial kidney model, especially with an unoccupied WC of the ureteroscope. Depending on the strength of force applied, very high pressure can be generated by most irrigation devices irrespective of whether the scope is occupied or not.

Thulium laser vaporesection of the prostate: Can we operate without interrupting oral antiplatelet/anticoagulant therapy?

Purpose

Thulium vaporesection of the prostate (ThuVARP) is a new and safe approach for patients receiving anticoagulant therapy in whom transurethral resection of the prostate (TURP) may possess a high bleeding risk. We aimed to demonstrate the efficacy and safety of ThuVARP in patients receiving oral antiplatelet/anticoagulant (OAP/OAC) therapy.

Materials and Methods

A total of 103 patients who underwent ThuVARP between 2011 and 2013 were enrolled in the study. Patients were divided into 2 groups. Group A consisted of 47 patients who underwent low molecular weight heparin (LMWH) bridging and group B consisted of 56 patients who were operated on while receiving OAP/OAC therapy.

Results

The drop in hemoglobin levels in the pre- and postoperative periods was significantly higher in group A than in group B. When subgroups were analyzed, the mean drop in hemoglobin was significantly lower in the warfarin and ticlopidine subgroups of group B than in group A. International Prostate Symptom Scores were significantly lower 3, 12, 18, and 24 months after surgery in group A than in group B. Quality of life scores, maximal flow rate values, and postmicturition residual urine volumes (mL) were similar between the 2 groups. A total of 38 and 41 patients in groups A and B, respectively, had no complications.

Conclusions

Our study showed the safety profile of continuing different OAP/OAC therapies in terms of bleeding problems in patients undergoing ThuVARP. We strongly recommend abandoning LMWH bridging and maintaining the OAP/OAC regimen patients are already receiving.

Ureteroscopic skills with and without Roboflex Avicenna in the K-box® simulator

Introduction

The aim of this study was to evaluate the acquisition of basic ureteroscopic skills with and without Roboflex Avicenna by subjects with no prior surgical training.

Material and methods

Ten medical students were divided in two groups: Group 1 was trained with Roboflex Avicenna and Group 2 with flexible ureteroscope alone, using the K-box^® simulator model. Participants were scored on their ability to perform or not two exercises, recording the time. In addition, the participants were evaluated on the quality of their performance for the following parameters: respect of the surrounding environment, flow of the operation, orientation, vision centering and stability.

Results

The first exercise was completed only by three and four out of five of students in Group 1 and Group 2, respectively. Stability with the scope was significantly more accurate in the first group compared with the second (P = 0.02). There were no differences in timing, flow or orientation between groups. Although not significant, a tendency of respecting the surrounding tissue and maintaining centered vision was perceived more in the first group. As for the second exercise, there were no differences between groups in regard of orientation, flow, respecting the surrounding tissue, stability or the ability of maintaining centered vision. Although not significant, the second group had a tendency of performing the exercise faster.

Conclusions

According to these preliminary results, the acquisition of basic ureteroscopic skills with and without robotic fURS in the K-box^® simulator, by subjects with no prior surgical training, is similar.

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.