Flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stone <2 cm: a meta-analysis

Recent advances in the treatment of renal stones using flexible ureteroscopys

Upper urinary tract stones are a common urological disease that can be treated by flexible ureteroscopy (FURS) through the natural urinary tract, in addition to extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy. The advantages of FURS are less trauma, faster recovery, and fewer complications, while its disadvantages include poor results of lithotripsy and stone extraction when dealing with larger stones, and prolonged operation time. Over the last two decades, the emergence of new technologies such as FURS combined with negative pressure suction, robot-assisted FURS, and artificially intelligent FURS, coupled with improvements in laser technology (the use of thulium fiber lasers and the invention of single-use flexible ureteroscopes (su-fURS) suitable for primary level application, have significantly increased the global adoption of FURS. This surge in usage holds a promising future in clinical application, benefiting a growing number of patients with renal calculi. Accompanied by changes in technical concepts and therapeutic modalities, the scope of indications for FURS is broadening, positioning it as a potential primary choice for urolithiasis treatment in the future. This review outlines the progress in employing FURS for the treatment of renal calculi in order to generate insights for further research.

Which Method Is More Effective for the Treatment of 1-2 cm Renal Pelvis Stones in Obese Patients: Extracorporeal Shock Wave Therapy or Flexible Ureterorenoscopy?

OBJECTIVE

This study aimed to compare the clinical outcomes and complications of obese patients who underwent extracorporeal shock wave lithotripsy (ESWL) and flexible ureterorenoscopy (FURS) for treating 1-2 cm renal pelvic stones.

METHODS

This study included 89 patients with a body mass index (BMI) >30 who underwent ESWL and FURS surgeries for 10-20 mm renal pelvic stones between January 2015 and July 2023. Three months after the treatments, patients underwent full abdominal computed tomography (CT) and were examined for stone-free status and the presence of residual stones. The presence of ≥4 mm residual stones on imaging was considered a failure, and these patients were treated again. Demographic data, stone characteristics, stone-free rate (SFR) three months after the procedure, surgery/procedure time, and complications such as bleeding, urosepsis, and collecting system perforation were compared between the groups.

RESULTS

The patients included in the study were divided into two groups: ESWL (n=46) and FURS (n=43). Demographic and clinical data were similar between the groups. Retreatment rates were higher in the ESWL group compared to the FURS group. The mean procedure time was similar between the groups (p=0.085). The three-month SFR was found to be higher in the FURS group (88.3% vs. 73.9%; p=0.043). There was no difference in complication rates between groups.

CONCLUSION

FURS is a more effective treatment method than ESWL in obese patients with stones 1-2 cm in size located in the renal pelvis.

Comparison of novel flexible and traditional ureteral access sheath in retrograde intrarenal surgery

OBJECTIVES

To compare the efficiency and safety of a novel flexible ureteral access sheath (f-UAS) and traditional ureteral access sheath (UAS) during retrograde intrarenal surgery (RIRS).

PATIENTS AND METHODS

Between January 2022 and September 2022, a total of 152 consecutive cases with renal stones underwent RIRS with the f-UAS. Their outcomes were compared with those of another 152 consecutive cases undergoing RIRS with traditional UAS using a 1:1 scenario matched-pair analysis, with matching parameters including age and stone size. The f-UAS is a novel UAS with a 10-cm-long tube at the tip that can follow the bends of flexible ureteroscope (f-URS).

RESULTS

Baseline characteristics were found to be similar between the two groups. The f-UAS group demonstrated significantly higher SFR (76.3% vs. 7.2%; P < 0.001) at 1 day postoperatively and a higher clearance rate of stone volume (98.11% vs. 91.78%; P < 0.001). The f-UAS group also had lower total complications rate (9.9% vs. 22.4%; P = 0.003), lower incidence of fever (5.9% vs 11.9%; P = 0.001), shorter operative times (56.5 min vs. 59.9 min; P = 0.047), and lower usage rate of baskets (17.1% vs. 100%; P < 0.001). There was no significant difference in SFR at 1 month postoperatively (P = 0.627) and in the length of postoperative hospital stay between the two groups (P = 0.225).

CONCLUSION

Compared to the traditional UAS during RIRS, the f-UAS showed several advantages, including higher SFR at 1 day postoperatively, shorter operative times, lower incidence of complications, and less use of basket.

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

Flexible Ureteroscopy: Global User Experience Using Disposable Devices

INTRODUCTION

Renal stone treatment through flexible ureteroscopy is widely established and successful. Ureteroscopes can broadly be classified into reusable and single-use disposable devices, each with their own advantages. Disposable scopes are cheaper to buy, maintain, and dispose of but may have a greater environmental impact and long-term cost. To establish the collective views of urologists, we conducted a multicentre, global study to demonstrate users' experience with single-use flexible ureteroscopes.  Methods: An online nine-question survey was distributed to urologists globally through email and social media platforms. Questions focused on user grade, experience, location, general opinion, advantages, disadvantages, and estimated cost of a single-use flexible ureteroscope. All responses were collated over a three-day period and analysed using descriptive statistics.

RESULTS

A total of 69 responses were received; the majority of responses were from the UK (75%), and most were consultants (64%). Two-thirds of those surveyed had used a single-use scope on a patient, and 95% of them stated they enjoyed using it, citing excellent vision and reduced need for maintenance. The majority (52%) stated that widespread adoption of disposable scopes was limited due to their prohibitive expense, with an average, sterling-converted responder-estimated cost of £991 (£100-£6000) per reusable scope.

CONCLUSION

Most urologists enjoyed using disposable scopes, finding them comparable or better than reusable devices. However, the initial cost can be prohibitive in certain centres. The potential environmental impact is a further concern as this remains largely unknown for now. In the meantime, it is likely that stone units will continue to use a combination of single-use and reusable scopes, considering their individual needs and budgets as well as local availability and price.

Flexible ureteroscopy under local anesthesia for stone management: initial exploration and two-year experience

BACKGROUND

Flexible ureteroscopy (f-URS) is a minimally invasive surgical technique used for treating urinary tract stones. While general anesthesia (GA) is the standard method used, it comes with risks. Local anesthesia (LA) is a safer and more cost-effective alternative to GA, and its use in f-URS could potentially reduce patients' risks and increase accessibility to treatment. This study aims to investigate the feasibility, safety, and efficacy of using LA for f-URS in treating stones, as an initial experience in the diagnosis related group (DRG) era of China.

METHODS

Patients who met the inclusion and exclusion criteria and were continuously included in the study Between 2021 and 2023. We analyzed the stone free status, postoperative complication rate, hospitalization costs, and presented key points of the procedure performed under LA that we had summarized over the past two years.

RESULTS

A study of 614 patients undergoing f-URS under LA for urinary stones in our hospital showed 83.4% stone-free rate with a mean operative time of 44.12 ± 16.63 minutes; 18 patients experienced fever postoperatively, and 12 had ureteral injuries. No severe complication was reported. The cost of LA was found to be only 1.7% of the DRG payment, which is around $40. The highest VAS scores were observed during the sheath insertion, with STAI scores decreasing during and after surgery.

CONCLUSIONS

The study revealed that f-URS administered under LA was a well-tolerated, efficient, safe, and economical procedure. In the DRG era, this new anesthetic option for f-URS provides urologists with a more cost-effective alternative.

Prospective comparison of extracorporeal shock wave lithotripsy versus flexible ureterorenoscopy in patients with non-lower pole kidney stones under the COVID-19 pandemic

Both shock wave lithotripsy (SWL) and flexible ureterorenoscopy (F-URS) are recommended as the first choice for non-lower pole kidney stones. Therefore, we conducted a prospective study to evaluate the efficacy, safety, and cost of SWL versus F-URS in patients with solitary non-lower pole kidney stones ≤ 20 mm under the COVID-19 pandemic. This prospective study was conducted in a tertiary hospital from June 2020 to April 2022. Patients who underwent lithotripsy (SWL or F-URS) for non-lower pole kidney stones were enrolled in this study. The stone-free rate (SFR), retreatment rate, complications, and cost were recorded. Propensity score-matched (PSM) analysis was performed. A total of 699 patients were finally included, of which 81.3% (568) were treated with SWL and 18.7% (131) underwent F-URS. After PSM, SWL showed equivalent SFR (87.9% vs. 91.1%, P = 0.323), retreatment rate (8.6% vs. 4.8%, P = 0.169), and adjunctive procedure (2.6% vs. 4.9%, P = 0.385) compared with F-URS. Complications were scarce and also comparable between SWL and F-URS (6.0% vs 7.7%, P > 0.05), while the incidence of ureteral perforation was higher in the F-URS group compared with the SWL group (1.5% vs 0%, P = 0.008). The hospital stay was significantly shorter (1 day vs 2 days, P < 0.001), and the cost was considerably less (1200 vs 30,083, P < 0.001) in the SWL group compared with the F-URS group. This prospective cohort demonstrated that SWL had equivalent efficacy with more safety and cost benefits than F-URS in treating patients with solitary non-lower pole kidney stones ≤ 20 mm. During the COVID-19 pandemic, SWL may have benefits in preserving hospital resources and limiting opportunity for virus transmission, compared to URS. These findings may guide clinical practice.

Comparison of shock wave lithotripsy and ureteroscopy in patients with proximal ureteral stones under the COVID-19 pandemic

PURPOSE

To compare the effectiveness, safety, and cost between ultrasound-guided shock wave lithotripsy (SWL) with an early second session protocol and ureteroscopy (URS) in patients with proximal ureteral stones using the propensity score matching (PSM) method based on a large prospective study.

METHODS

This prospective study was conducted in a tertiary hospital from June 2020 to April 2022. Patients who underwent lithotripsy (SWL or URS) for proximal ureteral stones were enrolled. The stone-free rate (SFR), complications, and cost were recorded. PSM analysis was performed.

RESULTS

A total of 1230 patients were included, of whom 81.1% (998) were treated with SWL and 18.9% (232) were treated with URS. After PSM, the SWL group had an equivalent SFR at one month (88.7 vs. 83.6%, P = 0.114) compared with the URS group. Complications were rare and comparable between the two groups, while the incidence of ureteral injuries was higher in the URS group compared with the SWL group (1.4 vs. 0%, P = 0.011). The hospital stay was significantly shorter (1 day vs. 2 days, P < 0.001), and the cost was considerably less (2000 vs. 25,053, P < 0.001) in the SWL group compared with the URS group.

CONCLUSION

This prospective PSM cohort demonstrated that ultrasound-guided SWL with an early second session protocol had equivalent effectiveness but better safety and lower cost compared with URS in the treatment of patients with proximal ureteral stones, whether the stones were radiopaque or radiolucent. These results will facilitate treatment decisions for proximal ureteral stones.

Comparison of Shock Wave Lithotripsy and Flexible Ureterorenoscopy in the Treatment of 10-20 mm Lower Pole Stone: Prospective Non-randomized Study

INTRODUCTION

The objective of the study is to clarify the efficiency, safety, and limitations of shock wave lithotripsy (SWL) and flexible ureterorenoscopy (f-URS) in the management of lower pole stones (LPS).

METHODS

The present study was planned prospectively in a non-randomized manner. Patients who had LPS between 10 and 20 cm in size were enrolled in the study. Patient demographic characteristics, stone-related parameters, complications, and success were noted. Patients who underwent SWL and patients who underwent f-URS were compared according to demographic characteristics, procedure-related parameters, complications, and success rate.

RESULTS

A total of 82 patients matched the study inclusion criteria, with 44 patients treated with SWL and 38 patients treated with f-URS. The time between diagnosis and the end of the treatment was 29.2 days in the SWL group and 15.2 days in the f-URS group (p = 0.001). The success rate was 89.5% with f-URS and 72.7% with SWL (p = 0.036). Receiver operating curve analysis revealed that a stone size larger than 14 mm in the lower pole was significantly associated with SWL failure (area under the curve [AUC]: 0.711, p = 0.033), and a stone size larger than 16 mm was a predictive factor for f-URS failure.

CONCLUSION

The present study found that f-URS had a significantly higher stone-free rate in the management of 10-20 mm LPS compared to SWL. For the first time, this study showed that the time between diagnosis and the end of treatment was significantly shorter with f-URS. Moreover, LPS larger than 14 mm and 16 mm were predictive factors for SWL and f-URS failure, respectively.

Patient-reported outcome measures (PROMs) in stone surgery: A multi-centre study of patient experience of flexible ureteroscopy (fURS) versus extracorporeal shockwave lithotripsy (SWL)

Objectives:

To compare patient-reported outcome measures (PROMs) for patients with symptomatic renal stone disease treated by flexible ureterorenoscopy (fURS) and shockwave lithotripsy (SWL)

Introduction:

Historically, surgical outcomes are measured by surgeon-specific outcomes such as ‘stone-free rates’. More recently, there is increasing emphasis on PROMs to ascertain a patient’s perspective of their own surgical outcome. Despite this, the literature in reference to renal stone-specific PROMs following stone treatment remains limited.

Methods:

Data were collected in a prospective multi-centre study. Patients undergoing fURS or SWL were asked to complete the validated Cambridge Renal Stone Patient Reported Outcome Measure ( CReSP) on the day of initial treatment and at weeks 1, 6 and 12 post-operatively.

Results:

Data were collected for 119 patients. Three were excluded as stone metric and demographic details were incomplete. Sixty underwent SWL and 56 underwent fURS. Median stone size was 7.52 mm. There were no significant differences in baseline PROM scores between the treatment groups. At 1 week, the PROM scores were significantly higher in the fURS group compared to SWL (27.40 ± 0.85sd versus 22.51 ± 1.07sd; p < 0.05). However, at 6 and 12 weeks, the PROM scores were significantly lower in the fURS group (18.51 ± 2.27sd versus 23.67 ± 1.30sd; p < 0.05) and (17.01 ± 2.29sd versus 22.49 ± 1.49sd; p < 0.05), respectively. By week 12, overall scores for anxiety and social factors were more favourable in the fURS cohort.

Conclusion:

Our study suggests that fURS is associated with a short-lived increase in morbidity in comparison with SWL, which may be due to ureteric stenting in the majority of patients post-operatively. However, fURS patients appear to report significantly better PROM scores in the longer term. This appears to be associated with more favourable anxiety and social factor scoring over the treatment period.

Level of evidence:

Not applicable.

Comparison of outcomes between flexible ureteroscopy and mini-percutaneous nephrolithotomy in the management of upper calyceal calculi larger than 2 cm

Objective

To compare the outcomes of FURSL and m-PNL in the management of upper calyceal calculi larger than 2 cm.

Methods

A total of 75 patients with upper calyceal calculi larger than 2 cm that were treated by FURSL (n = 37) or mini-PNL (n = 38) were retrospectively analysed. The mean age, sex, stone burden, operative time, complications, length of hospitalization, and stone-free rate (SFR) were compared between the groups. The success of the procedure was defined by the absence of residual stones or residual fragments smaller than 4 mm on computed tomography at 4 weeks postoperatively.

Results

The two groups had comparable preoperative parameters. The mean operative time was significantly longer in the mini-PNL group than in the FURSL group (87.8 vs. 69.8 min, p < 0.001). The length of hospitalization was greater in the mini-PNL group than in the FURSL group (2.5 vs. 1.3 days, p < 0.001). Although the perioperative complication rate was higher in the mini-PNL group (23.7%) than in the FURSL group (13.5%), this difference was not statistically significant (p = 0.258). The SFR for the mini-PNL group was 89.5%, and that of the FURSL group was 81.1%; the difference was not significantly different (p = 0.304).

Conclusions

Both FURSL and mini-PNL are effective and safe for the management of upper calyceal calculi larger than 2 cm. Of these two procedures, mini-PNL is less time consuming, FURSL is associated with faster recovery. FURSL can be considered a good alternative treatment in selected patients.

Safety and efficacy of extracorporeal shock wave lithotripsy vs. flexible ureteroscopy in the treatment of urinary calculi: A systematic review and meta-analysis

Objective

This study aims to compare the safety and efficacy of extracorporeal shock wave lithotripsy (SWL) and flexible ureteroscopy lithotripsy (f-URS) in treating urinary tract stones.

Methods

We systematically searched PubMed, Embase, and Cochrane for literature comparing SWL with f-URS. The primary outcomes we focused on were stone-free rate (SFR) and complications; the secondary outcomes were operation time, hospital stay, retreatment rate, number of sessions, and auxiliary procedures rate. We used ReviewManager version 5.4.1 and STATA version 14.2 for meta-analysis.

Results

Seventeen studies with a total of 2,265 patients were included in the meta-analysis, including 1,038 patients in the SWL group and 1,227 patients in the f-URS group. The meta-analysis indicated that patients in the f-URS group had higher SFR than those in the SWL group [odds ratio (OR): 2.00, 95% confidence interval (CI): 1.29–3.12, p = 0.002]. In addition, we found no significant difference in complications (OR: 1.08, 95% CI: 0.85–1.37) between the two treatments. Also, we found that the retreatment rate and the auxiliary procedure rate in the f-URS group were significantly lower than those in the SWL group (OR: 0.08, 95% CI: 0.02–0.24, p &lt; 0.00001; OR: 0.30, 95% CI: 0.11–0.83, p = 0.02). Moreover, the number of sessions in the f-URS group was significantly lower than that in the SWL group [mean difference (MD): −1.96, 95% CI: −1.55 to −0.33, p = 0.003]. However, the operation time and hospital stay in the f-URS group were significantly longer than those in the SWL group (MD: 11.24, 95% CI: 3.51–18.56, p = 0.004; MD: 1.14, 95% CI: 0.85–1.42, p &lt; 0.00001).

Conclusion

For 1–2-cm urinary stones, f-URS can achieve a higher SFR than SWL while having a lower retreatment rate, number of sessions, and auxiliary procedure rate. For urinary stones &lt;1 cm, there was no significant difference in SFR between SWL and f-URS groups. The SWL group has a shorter operative time and hospital stay than the f-URS group.

Microdamage analysis of single-use flexible ureteroscope immediately after lithotripsy use

This prospective ex vivo study investigated microdamage to single-use flexible ureteroscopes (fURS) after ureteroscopy and endoscopic combined intrarenal surgery (ECIRS). The performance of 30 WiScope devices (OTU Medical, San Jose, CA, USA) was examined immediately after use, dividing them into three equal groups: ureteroscopy and ECIRS in the prone and supine positions. The overall scope of microdamage assessment included the scope deflection, bending radius, resolution, and water flow rate. Additionally, we analyzed the association between scope status and surgical parameters. The deflection, bending radius, and resolution remained similarly above the thresholds in all groups. However, the water flow rate was below the threshold in seven scopes (70%) in the ureteroscopy group and none in the ECIRS groups (P = 0.001). Univariate and multivariable logistic regression analyses demonstrated that basket wire catheter use was associated with an increased risk for overall scope microdamage (odds ratio [OR], 22.70; P = 0.006 and OR, 22.40; P = 0.019, respectively). Stone size, total laser energy, and surgical position were not associated with a risk for scope microdamage. In conclusion, ureteroscopy was more closely associated with scope damage than ECIRS, and basket wire catheter use seemed to inflict more damage to the fURS.

Evaluation of the relation between size of stone and its attenuation measured by Hounsfield units and the total laser energy required to fragment it

BACKGROUND

Anticipating the total laser energy (TLE) of Holmium YAG laser required for ureteroscopic (URS) lithotripsy is essential to guide urologists in selecting the optimal fiber size. This study aimed at evaluating the relationship between stone size and stone attenuation measured by HU as predictors for the TLE during the procedure.

METHODS

We conducted an observational prospective cohort study of patients undergoing URS lithotripsy at the Urology department of Ain Shams University Hospitals from September 2018 to September 2019 with the use of a holmium YAG laser as the lithotripsy method. Patients' demographic and clinical characteristics, stone location, stone size, stone attenuation measured by HU from the non-contrast CT, TLE, and procedure time were recorded. Data were analyzed using Jamovi software (version 2.0 for macOS).

RESULTS

Forty patients were included in the study (22 males and 18 females) with a mean age of 57.8 years. The mean stone size was 9.8 mm³, the mean HU was 858.8 units, and the mean TLE was 3.5 KJ. Both stone size and stone attenuation measured by HU were positively correlated with TLE (r = 0.81 and 0.84, respectively; p < 0.001 for both). Further, regression analysis showed that both variables could significantly predict the TLE (ß = 0.001 and 0.71, respectively).

CONCLUSIONS

Both stone attenuation, as measured by HU, and stone size positively correlate with TLE required for URS lithotripsy. Therefore, both HU and stone size can predict the TLE, which will be helpful to guide the urologist in selecting the optimal fiber size for the procedure.

Comparison of two techniques for the management of 2-3 cm lower pole renal calculi in obese patients

OBJECTIVE

To compare the outcomes of mini percutaneous nephrolithotomy (mPNL) and retrograde intrarenal surgery (RIRS) for the management of 2-3 cm lower pole renal calculi (LPC) in obese patients.

PATIENTS AND METHODS

120 obese patients with 2-3 cm LPC were randomly divided into mPNL group and RIRS group. Demography, clinical characteristics, perioperative complications, and stone free rate (SFR) were recorded. Stone-free status means no stone on computed tomography 3 months after surgery, or residual fragments were less than 3 mm.

RESULTS

Baseline characteristics were similar between the two groups. The mean stone burden was 585.39 ± 131.06 mm² in the mPNL group and 548.64 ± 123.55 mm² in the RIRS group (P = 0.125). The SFR of mPNL group was significantly better than that of RIRS group (86.2% vs 61.4%, P = 0.002). Besides, the overall complication rate was 22.4% in the mPNL group and 7% in the RIRS group (P = 0.02). Patients performed with mPNL required longer length of hospital stay than those with RIRS (P = 0.001). There were no significant differences in operative time and stone composition between the two groups.

CONCLUSION

In our study, both mPNL and RIRS are safe and effective techniques for the treatment of 2-3 cm LPC in obese patients. Compared to RIRS, mPNL has better SFR at the expense of the higher incidence of complications and prolonged length of hospital stay.

Comparison Between Single-Use Flexible Ureteroscope and Reusable Flexible Ureteroscope for Upper Urinary Calculi: A Systematic Review and Meta-Analysis

Objective: This article explores the differences in the effectiveness and safety of the treatment of the upper urinary calculi between single-use flexible ureteroscope (su-fURS) and reusable flexible ureteroscope (ru-fURS).

Methods: We systematically searched PubMed, Embase, Cochrane Library, Scopus database, and CNKI databases within a period from the date of database establishment to November 2020. Stata 16 was used for calculation and statistical analyses.

Results: A total of 1,020 patients were included in the seven studies. The statistical differences were only found in the Clavien–Dindo grade II postoperative complication [odds ratio (OR) 0.47; 95% CI 0.23–0.98; p = 0.04]. No significant statistical differences were observed in operative time (OT), estimated blood loss (EBL), length of hospital stay (LOS), and stone-free rate (SFR).

Conclusion: Our meta-analysis results demonstrate that su-fURS, compared with ru-fURS, has similar effectiveness and better security for treating upper urinary calculi.

Is extracorporeal shockwave lithotripsy (SWL) still suitable for >1.5 cm intrarenal stones? Data analysis of 1902 SWLs

PURPOSE

According to the American Urological Association and European Association of Urology guidelines, shockwave lithotripsy (SWL) is the least-invasive treatment option for kidney stones smaller than 2 cm. However, it is well known that SWL stone-free rates (SFR) decline as stone size increases. We sought to evaluate whether the size limit of 1.5 cm could be a better predictor of success after a single SWL session than current recommendations.

METHODS

Data from an SWL-dedicated center were prospectively scrutinized according to stone locations and sizes. Information on patients' demography, lithotripsy parameters, and outcomes was evaluated by multivariate analysis among 1902 SWLs.

RESULTS

The overall SFR was 70.8% (1347/1902). SFRs according to stone size were <1 cm: 73.8% (825/1118), 1-1.5 cm: 70.4% (401/569) and >1.5 cm: 56.2% (121/215); and according to calculi location were lower pole (LP) 64.4% (398/618), mid pole 73.8% (339/459), upper pole 73.8% (273/370) and renal pelvis 74.1% (337/455). Multivariate analysis revealed better SFR independent better SFR in <1.5 cm (p < 0.01), and non-LP stones (p < 0.01).

CONCLUSION

SWL is an effective treatment modality for kidney stones. The single session reached up to 74.8% SFRs (range 70.8%-74.8%) when indicated for intrarenal non LP stones smaller than 1.5 cm. Patients with stones >1.5 cm or >1 cm located in the LP should be counseled on the lower SFRs after a single SWL session.

Can we successfully predict the outcome for extracorporeal shock wave lithotripsy (ESWL) for medium size renal stones? A single-center experience

BACKGROUND

Extracorporeal shock wave lithotripsy (ESWL) is one of the most used modalities in treatment of renal stones, but its effectiveness can be influenced by many factors related to the patient or the stone itself which may affect the success of stone disintegration. The aim of our study was to investigate the predictive value of some patient and stone-related factors for ESWL success for renal stones.

METHODS

A total of 100 patients with single radiopaque renal stone 10-20 mm in diameter, undergoing ESWL were enrolled in this study. All patients had non contrast computed tomography (NCCT) done before ESWL. We evaluated body mass index (BMI), skin-to-stone distance (SSD), stone size and Hounsfield density comparing these values between stone free (SF) and residual stone (RS) groups.

RESULTS

Of the 100 patients, 70% had successful disintegration. There was no significant difference between stone free (SF) and residual stone (RS) groups as regard age or BMI. Meanwhile, there was a significant difference between SF and RS groups as regard stones' density and SSD, with higher values in RS group but there was statistically insignificant difference as regard stone size (p = 0.522). Using logistic regression analysis, we found that Hounsfield unit (HU) was better in predicting successful disintegration than SSD but without statistical significance.

CONCLUSION

HU and SSD are the independent predictive factors for ESWL outcome, and they should be considered when planning ESWL in treatment of medium size renal stones.

Effectiveness of Flexible Ureterorenoscopy Versus Extracorporeal Shock Wave Lithotripsy for Renal Calculi of 5-15 mm: Results of a Randomized Controlled Trial

Background

Primary flexible ureterorenoscopy (URS) and extracorporeal shock wave lithotripsy (SWL) are treatment options in patients with renal calculi of 5-15 mm.

Objective

To compare effectiveness, complication rates, and pain scores between primary URS and SWL.

Design setting and participants

Between 2011 and 2016, patients with renal calculi between 5 and 15 mm were randomized to undergo either primary URS or SWL.

Outcome measurements and statistical analysis

Stone-free rate and size of residual fragments assessed by computed tomography after 3 mo, complications, and pain scores were evaluated.

Results and limitations

The study was prematurely closed after randomizing 44 patients due to poor accrual. The 3-mo stone-free rate and mean residual stone size were, respectively, 61% and 1.8 mm after URS and 48% and 2.4 mm after SWL. Early post-treatment pain scores were significantly higher after URS than after SWL on day 1 (3.3 vs 1.6, p =  0.02) and day 7 (5.2 vs 3.4, p =  0.04), but were no longer detectable after 3 wk and 3 mo, respectively. One Clavien-Dindo grade II complication was observed after URS (5%) and SWL (4%), while one (4%) grade IIIb complication was observed after SWL.

Conclusions

URS appears to be associated with higher early post-treatment discomfort, which could be associated with routine postoperative stenting. Owing to premature closure of this trial, the power was insufficient to formally compare URS and SWL; however, the present data might be informative to counsel patients about treatment outcomes and allow future meta-analyses.

Patient summary

This study was ended prematurely, but it contributes data about efficacy and side effects of different treatment options in patients with renal calculi.

Shock-wave lithotripsy, ureterorenoscopy and percutaneous nephrolithotomy for 1–2 cm renal stones: A randomised pilot study

Objectives:

This study aimed to assess which of extracorporeal shock-wave lithotripsy (SWL), ureterorenoscopy (URS) or percutaneous nephrolithotomy (PCNL) offers the best stone-free rate (SFR) for 1–2 cm renal stones.

Patients and methods:

A total of 31 patients with renal stones between 1 and 2 cm were randomised to SWL, URS or PCNL. Repeat treatments or alternatives were performed until the patient was stone free or clinically in no further need of treatment. All patients were assessed with computed tomography scanning independently reviewed by a radiologist blinded to the treatment.

Results:

Overall, 10 well-matched patients were randomised to SWL, 11 to URS and 10 to PCNL. SFRs were 60% for SWL, 55% for URS and 80% for PCNL (no significant difference). The mean number of procedures required were 2.6 (range 1–7) for SWL, 2.5 (range 1–4) for URS and 1.3 (range 1–3) for PCNL ( p=0.072). There were no major complications, but 50% of SWL had minor complications compared with 9% for URS and 20% for PCNL.

Conclusion:

The results for SWL were disappointing for SFR, number of procedures and complications. In common with other recent studies, the SFR following URS was also poor. PCNL had the best results for SFR with the fewest procedures. We calculate that an adequately powered study will require 42 patients per arm.

Level of evidence

Level 2b

Management of Migrated or Residual Stones Following Laparoscopic Pyelolithotomy and Ureterolithotomy in Abnormal Kidneys: A Prospective and Randomized Comparison

Objective: To conduct a prospective and randomized controlled trial comparing contemporaneous transabdominal rigid ureteroscopy (TRU) with postoperative extracorporeal shockwave lithotripsy (SWL) in the management of migrated or residual stones during laparoscopic pyelolithotomy and ureterolithotomy in kidneys with either intrinsic or extrinsic abnormalities. Materials and Methods: From February 2016 to December 2019, 45 patients with migrated or residual stones following laparoscopic pyelolithotomy and ureterolithotomy were accrued and randomly divided into two groups. These patients all had either urinary tract obstruction distal to the stone or concomitant ipsilateral intrinsic or extrinsic pathology requiring laparoscopic intervention. Twenty-three patients underwent contemporaneous TRU, and 22 patients underwent postoperative SWL. Patients' demographics, perioperative variables, and follow-up data were collected. The primary outcome was the final stone-free rate (SFR) at the 2-month follow-up. Secondary outcomes included blood loss, operative time, change in serum creatinine, complications per Clavien-Dindo grading system, renal colic occurrence rate (RCOR), and postoperative hospitalization. Results: There was no significant difference in gender, age, body mass index, location, or stone burden between the two groups (p > 0.05). At the 2-month follow-ups, the SFR was higher in the TRU than the SWL group (p = 0.002), and the RCOR was lower in the TRU than the SWL group (p = 0.005). Postoperative hospitalization was also shorter for the TRU group. No significant difference was noted in the operative time, blood loss, change in serum creatinine, or perioperative complications (p > 0.05). Conclusion: Contemporaneous TRU is more effective and equally safe compared to postoperative SWL in the management of residual or migrated stones during laparoscopic pyelolithotomy and ureterolithotomy in kidneys with either intrinsic or extrinsic abnormalities.

Prediction of stone-free rates following extracorporeal shockwave lithotripsy in a contemporary cohort of patients with stone densities exceeding 1000 HU

Purpose: Nephrolithiasis is a common urologic problem, and its incidence is increasing. Shockwave Lithotripsy (SWL) has better results for patients with stones < 1000 HU. We attempted to identify SWL stone-free (SF) predictors for > 1000 HU stones.Methods: From January 2013 to September 2019, patient shared decision consecutive SWL for the treatment of a single > 1000 HU renal stone diagnosed by non-contrast computed tomography (NCCT). Endpoints: Fragmentation and SF or clinically insignificant residual fragments ≤ 4 mm at 4 weeks. Age, gender, stone side, location, size and density, number and average energy (Joules) of shocks were explored on uni- and multivariate regression analysis.Results: All sixty-one patients included were diagnosed with renal stone between 5 and 20 mm (maximum length) and underwent one SWL session only: 62.3% males, median age 48 (21-80) years, mean stone size 9.43 ± 2.9 mm (6.0-20.0), mean density 1210 ± 135 HU (1000-1558). There were 39 (63.9%) cases of SF, 16 (26.2%) of partial success and six (9.8%) of no success. Stone size was the only independent predictor of fragmentation, OR = 1.83, 95% CI = 1.32-2.55, p = 0.0003, and SF OR = 1.91, 95% CI = 1.31-2.78, p = 0.008. The best discriminatory stone size on ROC analysis was 1 cm.Conclusion: Stone size was the only significant success predictor in our cohort, with 76% SF rate for stones < 1 cm in 4 weeks follow-up, supporting that renal stones > 1000 HU may be suitable to SWL.

A comparison among PCNL, Miniperc and Ultraminiperc for lower calyceal stones between 1 and 2 cm: a prospective, comparative, multicenter and randomised study

Background

Conventional Percutaneous Lithotripsy (PCNL) has been an effective, successful and easy approach for especially > 1 cm sized calyceal stones however risks of complications and nephron loss are inevitable. Our aim is to compare the efficacy and safety of PCNL, MiniPerc (MP) and UltraMiniPerc (UMP) for lower calyceal stones between 1 and 2 cm with a multicenter prospective randomized study.

Methods

Between January 2015 and June 2018, 132 consecutive patients with single lower calyceal stone were enrolled. Patients were randomized in three groups; A: PCNL; B: MP; C: UMP. 44 patients for the Group A, 47 for Group B and 41 for Group C. Exclusion criterias were the presence of coagulation impairments, age of < 18 or > 75, presence of infection or serious comorbidities. Patients were controlled with computerized tomography scan after 3 months. A negative CT or an asymptomatic patient with stone fragments < 3 mm size were the criteria to assess the stone-free status. Patient characteristics, stone free rates (SFR) s, complications and re-treatment rates were analyzed.

Results

The mean stone size were 16.38, 16.82 and 15.23 mm respectively in Group A, B and C(p = 0.34). The overall SFR was significantly higher in Group A (86.3%) and B (82.9%) as compared to Group C (78%)(p < 0.05). The re-treatment rate was significantly higher in Group C (12.1%) and complication rates was higher in Group A (13.6%) as compared to others(p < 0.05). The hospitalization was significantly shorter in Group C compared to Group A (p = 0.04).

Conclusions

PCNL and MP showed higher efficacy than UMP to obtain a better SFR. Auxiliary and re-treatment rates were higher in UMP. On the other hand for such this kind of stones PCNL had more complications. Overall evaluation favors MP as a better indication in stones 1–2 cm size.

The effects of shock wave lithotripsy and retrograde intrarenal surgery on renal function

Introduction: The aim of this study was to compare the early effects of shock wave lithotripsy (SWL) and retrograde intrarenal surgery (RIRS) on renal function using the cystatin C levels.Material and methods: Serum samples were taken from each of the patients preoperatively, on the first postoperative day, and on the 30th postoperative day in order to evaluate the renal damage. The cystatin C level was determined using a particle-enhanced turbid metric immunoassay with a clinical chemistry analyzer.Results: In the comparison between the preoperative and postoperative cystatin C levels on day 1, there was an increase in the SWL group (p = .001); however, the decrease in the RIRS group was statistically significant (p = .007). There were statistically significant differences in the cystatin C levels on the first postoperative day in both groups (p = .001). In the SWL group, there was a statistically significant increase between the preoperative and the 30th postoperative day cystatin C levels (p = .006), but no differences were found between these levels in the RIRS group or between the two groups (p = .255).Conclusions: RIRS may be the preferred procedure for patients who need more renal function protection when treating renal stones <2 cm.

Dusting versus fragmentation for renal stones during flexible ureteroscopy

Objectives: To compare stone dusting and spontaneous passage vs fragmentation and active fragment retrieval during flexible ureteroscopy (fURS) for renal calculi.

Patients and methods: The study included patients who underwent fURS and holmium laser lithotripsy for renal calculi from January 2015 to March 2017. Dusting was done using low energy and high frequency (0.3–0.5 J and 15–20 Hz, respectively), and fragmentation was done with higher energy and lower frequency (1–1.2 J and 6–10 Hz, respectively) and then stone fragments were extracted using a basket. The stone-free rate (SFR) was evaluated after 2 months with non-contrast computed tomography. Operative time, complication rate, SFR, and the need for secondary procedures were compared.

Results: The study included 107 consecutive patients, with a mean (SD) age of 49 (13) years. Dusting was performed in 51 patients and fragmentation in 56. The patients’ demographics, laboratory tests, preoperative stents, stone and renal characteristics were comparable for both groups. Operative time was significantly shorter for dusting than fragmentation (76 vs 91 min, P = 0.009). Complication rates were comparable between the groups (7.8% for dusting and 8.9% for fragmentation, P = 0.840). The mean hospital stay was comparable for both groups (P = 0.686). The SFR was significantly better in fragmentation group (78.6%) compared with the dusting group (58.6%, P = 0.035). The need for a secondary procedure was 33.3% in the dusting group and 23.3% in fragmentation group (P = 0.244).

Conclusions: During fURS for renal stones, the dusting technique had a significantly shorter operation time, whilst the fragmentation technique led to a significantly better SFR. Both techniques have comparable safety, hospital stay, and requirement for secondary procedures.

Abbreviations: fURS: flexible ureteroscopy/ureteroscope; ICU: intensive care unit; KUB: plain abdominal radiograph of the kidney, ureter and bladder; NCCT: non-contrast CT; SFR: stone-free rate; SWL: shockwave lithotripsy; UAS: ureteric access sheath

Single-use disposable digital flexible ureteroscopes: an ex vivo assessment and cost analysis

OBJECTIVE

To assess and measure the capability of a single-use disposable digital flexible ureteroscope, the LithoVue™ (Boston Scientific, Marlborough, MA, USA), and to assess if there is a benefit to switching to single-use scopes.

PATIENTS AND METHODS

The LithoVue was compared to two commonly used reusable flexible ureteroscopes (Olympus URF-V [Olympus, Tokyo, Japan] and Karl Storz Flex-X^c [Karl Storz & Co. KG, Tuttlingen, Germany]) ex vivo. An analysis of reusable ureteroscope usage was performed to evaluate damage, durability, and maintenance costs. This was then compared to the projected costs of using single-use disposable scopes.

RESULTS

Flexion, deflection and irrigation flow of the LithoVue was equivalent, if not better than the reusable flexible ureteroscopes. An analysis of 234 procedures with seven new Olympus URF-V scopes, revealed 15 scope damages. Staghorn stones and lower pole/mid-zone stones were significant risk factors for damage (P = 0.014). Once damage occurred it was likely to occur again. Total repair costs were $162 628 (Australian dollars) (£92 411 in Great British pounds), the mean cost per case was $695 (£395). Factoring in the purchase cost, cleaning and repair costs, the cumulative cost of 28 reusable flexible ureteroscopy procedures was ~$50 000 (£28 412). If the LithoVue was priced at $1 200 (£682), switching to a single-use scope would cost ~$35 000 (£19 888).

CONCLUSION

The LithoVue is analogous to reusable flexible ureteroscopes in regard to standard technical metrics. Depending on its purchase cost it may also represent a cost saving for hospitals when compared to the cumulative costs of maintaining reusable scopes. Additionally, urologist may consider using the scope in cases in which reusable scope damage is anticipated.

Shock-wave lithotripsy or ureterorenoscopy for renal stones?

Kidney stones are a common condition with high direct and indirect costs; to date, the optimal urological approach for some particular presentations including non-lower pole kidney stones between 10 and 20 mm of diameter is not clear. A limited number of randomized controlled trials and observational longitudinal studies suggests that ureterorenoscopy (URS) could be superior to shock-wave lithotripsy (SWL) in achieving stone-free rates in this setting; however, such reports are generally weakened by a number of limitations including small sample size and scarce control for confounding. In this issue, Fankhauser et al. [1] report the results of a large observational retrospective study on the comparative efficacy and safety of URS and SWL for the treatment of previously untreated kidney stones.

Surgical management of urolithiasis - a systematic analysis of available guidelines

Background

Several societies around the world issue guidelines incorporating the latest evidence. However, even the most commonly cited guidelines of the European Association of Urology (EAU) and the American Urological Association (AUA) leave the clinician with several treatment options and differ on specific points. We aimed to identify discrepancies and areas of consensus between guidelines to give novel insights into areas where low consensus between the guideline panels exists, and therefore where more evidence might increase consensus.

Methods

The webpages of the 61 members of the Societé Internationale d’Urologie were analysed to identify all listed or linked guidelines. Decision trees for the surgical management of urolithiasis were derived, and a comparative analysis was performed to determine consensus and discrepancies.

Results

Five national and one international guideline (EAU) on surgical stone treatment were available for analysis. While 7 national urological societies refer to the AUA guidelines and 11 to the EAU guidelines, 43 neither publish their own guidelines nor refer to others. Comparative analysis revealed a high degree of consensus for most renal and ureteral stone scenarios. Nevertheless, we also identified a variety of discrepancies between the different guidelines, the largest being the approach to the treatment of proximal ureteral calculi and larger renal calculi.

Conclusions

Six guidelines with recommendations for the surgical treatment of urolithiasis to support urologists in decision-making were available for inclusion in our analysis. While there is a high grade of consensus for most stone scenarios, we also detected some discrepancies between different guidelines. These are, however, controversial situations where adequate evidence to assist with decision-making has yet to be elicited by further research.

Extracorporeal shock wave lithotripsy versus flexible ureterorenoscopy in the treatment of untreated renal calculi

Background

The reported success rates for treatments of kidney stones with either extracorporeal shock wave lithotripsy (ESWL) or flexible ureterorenoscopy (URS) are conflicting. We aimed to compare the efficacy and safety of ESWL and URS for previously untreated renal calculi.

Methods

All patients treated with ESWL or URS at our tertiary care centre between 2003 and 2015 were retrospectively identified. Patients with previously untreated kidney stones and a stone diameter of 5–20 mm were included. Stone-free, freedom from reintervention and complication rates were recorded. Independent predictors of stone-free and freedom from reintervention rates were identified by multivariable logistic regression and a propensity score-matched analysis was performed.

Results

A total of 1282 patients met the inclusion criteria, of whom 999 (78%) underwent ESWL and 283 (22%) had URS. During post-operative follow-up, only treatment modality and stone size could independently predict stone-free and freedom from reintervention rates. After propensity score matching, ESWL showed significantly lower stone-free rates [ESWL (71%) versus URS (84%)] and fewer patients with freedom from reintervention [ESWL (55%) versus URS (79%)] than URS. Complications were scarce for both treatments and included Clavien Grade 3a in 0.8% versus 0% and Grade 3b in 0.5% versus 0.4% of ESWL and URS treated patients, respectively.

Conclusions

Treatment success was mainly dependent on stone size and treatment modality. URS might be the better treatment option for previously untreated kidney stones 5–20 mm, with similar morbidity but higher stone-free rates and fewer reinterventions than ESWL.

Laparoscopic pyelolithotomy as a monotherapy for the management of intermediate-sized renal pelvic stones

Introduction:

Renal calculi are one of the major reason leading to kidney failure or urinal obstructions. Percutaneous nephrolithotomy is considered as the major management option for intermediate to large renal pelvic stones. In the present study we compare Percutaneous nephrolithotomy vs laparoscopic pyelolithotomy procedures in the management of intermediate sized renal pelvic stones.

Methods:

The time duration of study was between July 2012 and Jan 2014, 20 patients with solitary intermediate sized renal pelvic stones were selected and randomly divided into two groups; group one included 10 patients who were treated by laparoscopic pyelolithotomy and group two included 10 patients who were treated by PCNL. The differences in procedure time, blood loss, stone clearance and duration of hospital stay between the two procedures were compared and analyzed.

Results:

There was no difference between the two groups regarding patient demographics and stone size. There was statistically significant difference between laparoscopic pyelolithotomy and PCNL regarding mean estimated blood loss (<50 mL vs. 180–250 mL), hospital stay (3–5 days vs. 4–6 days), mean time of postoperative analgesia (2.2 ± 0.9 days vs. 2 ± 0.9 days), and stone-free rate (100% vs. 95%). The operative time was significantly longer in the laparoscopic pyelolithotomy group (80–150 min vs. 45–75 min).

Conclusion:

Although PCNL is the gold standard for intermediate-sized renal pelvic stones of 2-4 cm, laparoscopic pyelolithotomy is a suitable surgical technique in selected cases.

To Dust or Not To Dust: a Systematic Review of Ureteroscopic Laser Lithotripsy Techniques

PURPOSE OF REVIEW

This review discusses factors affecting outcomes during ureteroscopy (URS) with laser lithotripsy (LL), explores specific clinical challenges to the efficacy of URS LL, and reviews the available literature comparing the dusting and basketing approaches to URS LL.

RECENT FINDINGS

Data show high stone-free rates with URS LL in all locations of the urinary tract and with all stone types and sizes. Recent data comparing LL with dusting versus basketing suggest higher rates of residual fragments with dusting but less utilization of ureteral access sheaths and potentially shorter operative times. Differences in postoperative complications, re-intervention rates, and other outcome parameters are not yet clear. Interpretation of published data is problematic due to variability in laser settings, follow-up intervals, and definitions for what constitutes stone-free status. URS has overtaken shock wave lithotripsy in the last decade as the most commonly utilized surgical approach for treating urolithiasis. Two primary strategies have emerged as the most common techniques for performing LL: dusting and basketing. There is a relative paucity of data examining the difference in these techniques as it pertains to peri-operative outcomes and overall success. We attempt to synthesize this data into evidence-based and experience-based recommendations.

Management of lower pole renal stones: the devil is in the details

Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) are highly effective treatment options for lower pole stones up to 2 cm. Selecting the best treatment modality represents a controversial area in urology, because each treatment methods have their own advantages and disadvantages. Donaldson and co-workers have recently published a very comprehensive review and meta-analysis to compare the benefits and harms of SWL, RIRS and PNL techniques.