Exaggerated primary endoscope deflection: initial clinical experience with prototype flexible ureteroscopes

How to evaluate a flexible ureterorenoscope? Systematic mapping of existing evaluation methods

Objectives

The objective of this study was to identify, map and review scope‐related and user‐related parameters used to evaluate the quality of flexible ureterorenoscopes. Thereby identifying key items and variability in grading systems.

Methods

A literature search of four databases (MEDLINE [Ovid], EMBASE [Ovid], Web of Science, Google scholar and the Cochrane Library) was performed according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines encompassing articles published up to August 2020. A total of 2386 articles were screened.

Results

A total of 48 articles were included in this systematic scoping review. All studies had a prospective design. Five key items in the assessment of flexible ureterorenoscopy were distinguished: ‘Manoeuvrability’ (87.5%), ‘Optics’ (64.6%), ‘Irrigation’ (56.3%), ‘Handling’ (39.6%) and ‘Durability’ (35.4%). After regrouping, every key item could be divided into specific subcategories. However, the quality assessment showed a wide variation in denomination, method of measurement, circumstances of measurement, tools used during measurements, number of measurements performed, number of observers, and units of outcomes.

Conclusion

The research field regarding quality assessment of ureterorenoscopes is heterogeneous. In this systematic scoping review we identified five key parameters: Manoeuvrability, Optics, Irrigation, Handling and Durability, used to grade flexible ureterorenoscopes. However, within these categories we found a wide variety in terms of method of measurements. A standardised, uniform grading tool is required to assess and compare the quality of flexible ureterorenoscopes in the future.

Miniaturized percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of renal stones with a diameter <15 mm: A 3-year open-label prospective study

Aim

The aim of this study is to compare the outcomes of miniaturized percutaneous nephrolithotomy (mini-perc) and retrograde intrarenal surgery (RIRS) in management of renal stones with a diameter <15 mm.

Materials and Methods

This was an open-label prospective study that included a total of 80 cases underwent mini-perc (n = 40) and RIRS (n = 40) between July 2014 and August 2017. The primary outcome objective was stone-free rate, retreatment rate, complications, hospital stay, operative time, and reduction in hemoglobin level. Data were analyzed using SPSS version 16.0 Software.

Results

Overall, 80 patients were enrolled in this study. The mean age was 40.12 and 38.20 years, and the mean stone size was 1.15 and 1.30 cm in mini-perc and RIRS group, respectively. Majority of the study participants were males. Overall, mini-perc and RIRS had stone clearance rates of 100% and 95.4%, respectively. Two patients required retreatment in RIRS group. The duration of hospital stay and the rate of complication was similar in both the groups. Operative duration was more in RIRS group. Decrease in hemoglobin level was more in mini-perc group.

Conclusions

Results demonstrated that both modalities were associated with high stone clearance rates with minimal complications. RIRS was associated with less reduction in hemoglobin and could be used as standard treatment modality for small renal calculi.

Extracorporeal Shockwave Lithotripsy Versus Flexible Ureteroscopy for the Management of Upper Tract Urinary Stones in Children

OBJECTIVE

To compare the efficacy and morbidity of extracorporeal shockwave lithotripsy (SWL) and flexible ureteroscopy (F-URS) for the management of upper tract urinary stones in children.

METHODS

All SWL and F-URS performed in children in a single institution between 2000 and 2014 were reviewed retrospectively. Only procedures performed to treat upper tract urinary stones (upper ureter or kidney) were included in this study. Preoperative and perioperative outcomes were compared between the SWL and F-URS groups. Univariate and multivariate logistic regression analyses were used to evaluate predictors of stone-free (SF) status.

RESULTS

Over the study period, 100 SWL and 46 F-URS were conducted in 69 children. The SWL and F-URS groups were comparable in terms of stone size (14.6 vs 13.2 mm, p = 0.32), but there were more multiple stones (31% vs 57%; p = 0.003) and lower pole calculi (14% vs 37%; p = 0.003) in the F-URS group. The SF rate after one procedure was almost two times higher in the F-URS group compared with the SWL group (37% vs 21%; p = 0.04) without increasing the complication rate (21.7% vs 16%; p = 0.31). Similar results were observed in the subgroup of single renal stones <20 mm (SF rates: 78.6% vs 50%; p = 0.06). In multivariate analysis, the use of F-URS vs SWL was a predictor of an SF status (odds ratio = 3.7; p = 0.02).

CONCLUSION

F-URS provides a higher single-session SF rate, despite more complex urinary stones (multiple, lower pole, etc.) and without increasing morbidity.

The efficacy of performing shockwave lithotripsy before retrograde intrarenal surgery in the treatment of multiple or large (≥1.5 cm) nephrolithiasis: A propensity score matched analysis

Purpose

To investigate the effect of performing shockwave lithotripsy (SWL) before retrograde intrarenal surgery (RIRS) on the treatment outcomes of patients with nephrolithiasis.

Materials and Methods

The data of 189 patients with renal stones who underwent RIRS from July 2007 to July 2014 was reviewed retrospectively. Patients with stones larger than 1.5 cm were recommended to undergo SWL before RIRS. Patients were divided into 2 groups based on whether the preoperative SWL was performed (group 1, n=68) or not (group 2, n=121). The cohorts of the 2 groups cohorts were matched 1:1 using propensity score analysis. Patient, stone characteristics, operative parameters, and stone-free rates were compared.

Results

Patients in groups 1 and 2 were matched with respect to stone size, number, and location, leaving 57 patients in each group. After matching, no differences were identified between the 2 groups regarding age, body mass index, sex, stone composition, density and multiplicity. Compared to group 2 patients, patients in group 1 had fewer number of procedures performed (1.10 vs. 1.26, p=0.045) and higher stone-free rate (89.4% vs.73.6%, p=0.039). In multivariate analysis, Non lower calyceal location (odd ratio [OR], 8.215; 95% confidence interval [CI], 1.782–21.982; p=0.041), stone size (OR, 6.932; 95% CI, 1.022–18.283; p<0.001), and preoperative SWL (OR, 2.210; 95% CI, 1.058–7.157; p=0.019) were independent factors predicting a stone-free state after RIRS.

Conclusions

Performing SWL before RIRS may favor stone eliminations during surgery and increase the stone-free rate in selected patients.

Ureteroscopy and laser lithotripsy: technologic advancements

Ureteroscopic lithotripsy has evolved since the first reported cases employing rigid rod-lens endoscopes and stiff ultrasonic lithotrites. Fiber optics facilitated rigid endoscope miniaturization and the development of a steerable, deflectable flexible ureteroscopes. Over 30 years of technical innovations culminating in digital imagers and powerful, precise laser lithotrites, complimented by progressive endoscopic techniques have produced efficient endoscopic therapies with minimal morbidity and commonly performed in an outpatient setting.

Modified Seoul National University Renal Stone Complexity score for retrograde intrarenal surgery

The Seoul National University Renal Stone Complexity (S-ReSC) score is a well-validated tool for the prediction of stone-free rate (SFR) after percutaneous nephrolithotomy. We modified the S-ReSC score system for application to retrograde intrarenal surgery (RIRS) and evaluated this score. A total of 88 patients who underwent RIRS from 2011 to 2013 were included. The modified S-ReSC score was assigned according to the number of sites involved in the renal pelvis (#1), superior and inferior major calyceal groups (#2-3), and anterior and posterior minor calyceal groups of the superior (#4-5), middle (#6-7), and inferior calyx (#8-9). If the stone was in the inferior sites (#3, #8-9), one additional point per site was added to the original score. The SFR was examined according to the modified S-ReSC score. To evaluate the predictive accuracy, the area under the receiver operating characteristic curve (AUC) was used and compared with the Resorlu-Unsal Stone (RUS) score. The SFR was 85.2% and was significantly decreased in the order of low (1-2: 94.2%), medium (2-4: 84.0%), and high (>4: 45.5%) modified ReSC score groups (p < 0.001). AUCs of the modified S-ReSC score (0.806) and score group (0.766) were higher than the AUC of the RUS score (0.692; p = 0.012 and p = 0.040, respectively). The modified S-ReSC score predicts the SFR after RIRS well. Furthermore, its predictive accuracy is higher than that of the RUS score.

Comparison of percutaneous nephrolithotomy, shock wave lithotripsy, and retrograde intrarenal surgery for lower pole renal calculi 10-20 mm

OBJECTIVE

To compare the results of percutaneous nephrolithotomy (PCNL), shock wave lithotripsy (SWL), and retrograde intrarenal surgery (RIRS) for 1- to 2-cm lower pole kidney stones.

PATIENTS AND METHODS

This retrospective study was based on data collected from the files of patients between January 2007 and May 2012. The files of 383 patients (221 SWL, 144 PCNL, 38 RIRS) were evaluated. The groups were compared for stone size, success rate, and complication rate using the modified Clavien grading system.

RESULTS

The stone burdens of the groups were similar (p = 0.36). The success rates were 76, 94, and 73%, respectively, in SWL, PCNL, and RIRS. The highest stone-free rate was in the PNL group (p < 0.05). When the complication rates were evaluated using the Clavien grading system, they were determined to be 13% in PCNL, 3% in SWL, and 5% in RIRS. Especially GII and GIII complications were more common in the PCNL group (p < 0.05).

CONCLUSION

PCNL seems to be the most successful but most invasive method. However, with relatively low complication rates, SWL and RIRS are other techniques to keep in mind. To determine the first-line treatment, prospective randomized studies with larger series are needed.

A randomized controlled study to analyze the safety and efficacy of percutaneous nephrolithotripsy and retrograde intrarenal surgery in the management of renal stones more than 2 cm in diameter

OBJECTIVE

The gold standard for removal of renal stones more than 2 cm in diameter is percutaneous nephrolithotripsy (PCNL). Retrograde intrarenal surgery (RIRS) has become more and more fashionable because of its high safety and repeatability, especially in smaller stones. Many retrospective studies have proved its efficacy and safety in larger calculi, however. We decided to compare prospectively both procedures in terms of safety and efficacy in renal pelvic stones more than 2 cm in diameter.

PATIENTS AND METHODS

This was a randomized single tertiary care center trial with two arms (32 patients in each arm). The first group comprised patients who underwent PCNL, while in the second group, there were patients in whom RIRS with a semirigid ureteroscope was used. The primary end points were hematocrit and hemoglobin drop after surgery as equivalents of safety and stone disintegration rate in terms of efficacy. The secondary end points comprised operating room time, visual analogue scale of pain, pain treatment, and hospital stay.

RESULTS

The mean hematocrit drop after the procedure was lower in the second group. Similarly, operating room time and hospital stay were significantly shorter after RIRS in comparison with PCNL. In the second group, patients had favorable features in terms of pain intensity and treatment after the procedure. PCNL showed higher efficacy (94%) in comparison with RIRS (75%). The power of 83% was calculated for the primary end point.

CONCLUSION

The efficacy of RIRS is acceptable and, emphasizing its high safety, it should be considered as a valuable alternative option for management of renal pelvic stones more than 2 cm in diameter.

Flexible ureteroscopy update: indications, instrumentation and technical advances

Retrograde ureteroscopy has recently gained a broadened indication for use from diagnostic to a variety of complex minimally invasive therapies. This review aims to look at the recent advances in the instrumentation and accessories, the widened indications of its use, surgical techniques and complications. With minimization of ureteroscopic instruments manufacturers are challenged to develop new, smaller and sturdier instruments that all will also survive the rigors of surgical therapy.

Lower pole calculi larger than one centimeter: Retrograde intrarenal surgery

Controversy remains on how to treat lower pole calculi between 1 and 2 cm of size. Treatment options like shock wave lithotripsy (SWL) or percutaneous stone treatment (PCNL) are associated with poor stone-free rates or high morbidity.

Due to the ongoing development in endourologic technology, especially in flexible renoscopy, laser technique and grasping devices (tipless Nitinol baskets) retrograde intrarenal surgery (RIRS) has become an option in treating these patients.

Based on personal experience and an overview of the published literature we discuss RIRS as a valuable alternative to PCNL in treating patients with larger calculi of the lower pole.

The technical developments in laser technology as well as significant improvement in flexible renoscopes have made RIRS for larger lower pole stones possible. The low complication rate gives RIRS for lower pole stones superiority over the invasive percutaneous approach, which is associated with significant morbidity, even in experienced hands.

Working tools in flexible ureterorenoscopy--influence on flow and deflection: what does matter?

INTRODUCTION

Flexible renoscopes offer access to almost all points within the collecting system. For stone workup, excellent visualization is mandatory. Therefore, irrigation flow is of critical importance. The aim of this study was to evaluate the effect of tools and probes on deflection angle and irrigation flow volume in the latest generation of flexible renoscopes.

METHODS

Five flexible renoscopes [Wolf (Viper), Storz (FlexX(2)), ACMI (DUR-8 Elite, DUR-D), Olympus (URF-P5)] were tested. Deflection angle, lowest diameter of the bent tip, and flow rates were measured. Recorded parameters were deflection angle and flow rate of the empty and loaded scopes. A laser probe (273 mum), biopsy forceps (2.4-3.0 French), and tipless nitinol baskets (1.5-2.4 French) were tested.

RESULTS

Deflection has no influence on flow rate. The size of the basket has no influence on the maximum angle of deflection. Introducing the laser fiber or the biopsy forceps leads to relevant loss of deflection (laser fiber: 4.44%-10.21%; biopsy forceps: 30.7%-57.8%). The inner diameter of the bent tip increases with introduction of a laser fiber (+1 to 3 mm) or the biopsy forceps (+13 to 34 mm). Flow rates are dependent on the size of the tool used. Loss of irrigation volume varies from 62.24% (1.5 French) to 99.1% (3.0 French). The use of a laser fiber leads to a decrease in irrigation volume of 53.7%.

CONCLUSION

Irrigation flow, loss of deflection, and intraoperative visualization are dependent on the working tool used. The provided data, in awareness of the patient's anatomy, help to select scopes, probes, and tools correctly for successful ureterorenoscopy.

Update on flexible ureteroscopy

OBJECTIVE

An update on ureteroscopy with focus on current technology and newer instrumentation is presented.

METHODS

A literature search through Medline-indexed journals as well as personal comments are included in this review. Topics such as new semirigid and flexible ureteroscopes, lasers, ureteral access sheats, wires and stone extraction devices are outlined.

RESULTS

Thanks to the continuous advances of technology and miniaturization of instruments, ureteroscopy is an ever-expanding field. A clear outline of the available instruments and techniques with reference to published results catches the status of this dynamic field.

CONCLUSIONS

Urologists are faced with a host of new products related to ureteroscopy every year. This review serves to identify the most useful and proven advances in the field and helps in selecting the equipment needed for a successful minimally invasive approach to upper urinary tract pathologies.

Advanced Ureteroscopy: Wireless and Sheathless

BACKGROUND

The introduction of a new generation of flexible ureteroscopes significantly advanced the therapeutic and diagnostic efficacy of the instrument, allowing greater access to all aspects of the upper urinary tract and facilitating wireless ureteroscopy.

PATIENTS AND METHODS

Four hundred sixty consecutive upper urinary-tract procedures were performed utilizing the 7.5F actively deflectable, flexible ureteroscope. A prospective database of these procedures was maintained. The indications, access technique, complications, success rate of stone treatment, and access to lower-pole calices were evaluated. The accumulated clinical data were compared with a published database of 1000 consecutive flexible ureteroscopies.

RESULTS

A stent was in place or had recently been in place in 108 of the procedures (24%). Of the remaining 352 flexible ureteroscopic procedures, only 11% (52) required any form of ureteral dilation to facilitate ureteral access. Two hundred twenty seven procedures were performed in which no guidewire was required to place the flexible endoscope in the upper urinary tract (i.e., "wireless" ureteroscopy).

CONCLUSION

Wireless no-touch flexible ureteroscopy with the new flexible instruments is a feasible and safe technique for diagnostic and therapeutic procedures in most patients, irrespective of the location of the pathology, including the distal ureter. These ureteroscopes, with their exaggerated deflection, are ushering in a new era of endoscopic treatment of the upper urinary tract. Greater instrument deflectability and control can lead to shorter procedures and fewer treatment failures.

Incontinence after radical prostatectomy: surgical treatment options

PURPOSE OF REVIEW

Stress urinary incontinence is an uncommon finding in healthy men. Following radical prostatectomy, however, stress urinary incontinence is the most important complication influencing patient morbidity following surgery and influencing satisfaction, regardless of the surgical technique applied. Conservative treatment options centre at early restoration of bladder and pelvic floor function. When significant and bothersome stress urinary incontinence persists, even after six to 12 months active treatment follow-up, surgical restoration of continence seems advisable.

RECENT FINDINGS

Two themes emerge in reviewing the recent publications in this field. Implantation of the hydraulic artificial urinary sphincter is still the gold standard, particularly in severe cases. Alternatively, new techniques and other artificial materials are gaining favour, aiming at a large cohort of patients with less severe incontinence, which have been not treated or overtreated so far. Advances in both areas are covered within this review article in detail.

SUMMARY

For treatment of incontinence following prostatectomy, a large variety of surgical techniques are readily available and have proven to be helpful tools in making patients' uncomfortable lives much easier. In addition, the wide armamentarium of artificial materials and techniques may help to choose the proper surgical technique for every patients' needs.

An update on ureteroscopic instrumentation for the treatment of urolithiasis

PURPOSE OF REVIEW

Ureteroscopic instruments, both endoscopic and working devices, continue to evolve. Changes in instrumentation have necessitated concurrent modifications in ureteroscopic techniques over the years. The safety and efficacy of the ureteroscopic approach for the treatment of renal and ureteral calculi, however, have continued to improve.

RECENT FINDINGS

This review emphasizes the recent advances in the major groups of instruments employed for ureteroscopy. Among the endoscopic instruments, the flexible ureteroscopes have undergone the most notable advances, benefiting from greatly improved deflection and durability. Progress has been made in adjunctive instruments as well. Current stone retrieval devices composed of nitinol-based wire technology are able to easily secure fragments from the most peripheral calices. The holmium laser is a versatile device with proven safety and effectiveness as an endoscopic lithotrite.

SUMMARY

The availability and coordinated use of the latest ureteroscopic instruments have resulted in better treatment outcomes, thus expanding the use of ureteroscopy as a first-line option for the treatment of calculi in appropriate cases. Urologists should be familiar with currently available instrumentation in order to optimize their equipment.