Ureteroscopic Treatment of Lower Pole Calculi: Comparison of Lithotripsy In Situ and After Displacement

Ureteroscopy and lasertripsy for lower pole stones <2 cm, in situ vs displacement? A systematic review and meta-analysis

OBJECTIVE

To investigate the outcomes of ureteroscopy and lasertripsy in lower pole renal stones <2 cm when treated in situ compared to displacement to the upper pole.

PATIENTS AND METHODS

Using the Medical Literature Analysis and Retrieval System Online (MEDLINE)/PubMed, the Excerpta Medica dataBASE (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Library, and Clinicaltrials.gov we identified adult population, English language, studies published until March 2023 comparing surgical outcomes and stone-free rates (SFRs) in relation to lower pole stones <2 cm managed in situ vs those displaced (International Prospective Register of Systematic Reviews [PROSPERO] identifier: CRD42023432750). Analysis was performed using R with the 'meta' package. Bias analysis was performed using the Cochrane Risk of Bias 2 tool for randomised trials and the Newcastle-Ottawa scale for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to ascertain the certainty of evidence.

RESULTS

A total of five studies were included, comprising two retrospective cohort studies, three randomised trials, with a total of 408 patients. Meta-analysis demonstrated SFRs are significantly higher in those patients undergoing displacement vs those managed in situ (risk ratio 1.21, 95% confidence interval [CI] 1.10-1.34, P < 0.001). There was no significant difference in complication rates. Operative time was significantly longer in the displacement group (mean difference 5.62 min, 95% CI 0.40-10.83 min; P = 0.03). Overall risk of bias was moderate. Certainty of evidence was moderate for stone-free status, and very low for all other outcomes.

CONCLUSIONS

This systematic review and meta-analysis demonstrates that for lower pole stones <2 cm displacement strategies have significantly higher SFRs than treatment in situ, with no significant difference in complications. There is significantly increased operative time in the displaced group, but an additional 6 min is unlikely to be clinically significant.

The relationship between stone-free and patient position in retrograde intrarenal surgery: a randomized prospective study

PURPOSE

Residual fragments not removed with urinary stone surgery may become symptomatic. In this context, this study was carried out to investigate the effect of performing retrograde intrarenal surgery, which is conventionally performed in the lithotomy position, in the modified lithotomy position (Trend-side) on stone-free rates following the surgery.

METHODS

This prospective study consisted of 100 patients with a single kidney stone smaller than 2 cm between 2021 and 2023. These patients were randomized into two groups of 50 patients each to be operated on in the conventional lithotomy and Trend-side positions. Variables were compared using independent t test for continuous variables and chi-square test for categorical variables.

RESULTS

There was no significant difference between the lithotomy and Trend-side position groups in terms of preoperative size, density, location of the stone, and hydronephrosis degree. Stone-free rate was 72% (n = 36) in the lithotomy group and 92% (n = 46) in the Trend-side group. Hence, there was a significant difference between the groups in the stone-free rate in favor of the Trend-side group (p = 0.009). Fragmentation time was statistically significantly shorter in the Trend-side group than in the lithotomy group (34 ± 17 min vs. 43 ± 14 min; p = 0.006). There was no significant difference between the groups in postoperative complication rates.

CONCLUSION

Performing retrograde intrarenal surgery in the Trend-side position shortened the duration of fragmentation compared to the lithotomy position and was associated with higher stone-free rates. In conclusion, the Trend-side position can be safely preferred in patients undergoing retrograde intrarenal surgery due to kidney stones.

Relocation of lower pole renal stones helps improve the stone-free rate during flexible ureteroscopy with a low complication rate

OBJECTIVE

To compare the efficacy and safety of relocating the lower pole stones to a favorable pole during flexible ureteroscopy with in situ lithotripsy for the treatment of 10-20 mm lower pole stone (LPS).

METHODS

This study was a prospective analysis of patient outcomes who underwent an FURS procedure for the treatment of 10-20 mm lower pole renal stones from January 2020 to November 2022. The patients were randomized into a relocation group or in situ group. The LPSs were relocated into a calyx, during lithotripsy in the relocation group was performed, whereas the in situ group underwent FURS without relocation. All the procedures were performed by the same surgeon. The patients' demographic data, stone characteristics, perioperative parameters and outcomes, stone-free rate (SFR), complications, and overall costs were assessed retrospectively.

RESULTS

A total of 90 patients were enrolled and analyzed in this study (45 per group) with no significant differences between the two groups in terms of age, gender, BMI, diabetes, hypertension, stone size, number, laterality, composition, and density. The mean operation time, total energy consumption, postoperative stay, and complications were similar between the groups. Both groups had similar SFR at 1 day postoperative follow-up (p = 0.091), while the relocation group achieved significantly higher SFR 3 months later (97.8% vs 84.4%, p = 0.026). The relocation group also had a significantly higher WisQol score than the in situ group (126.98 vs 110.18, p < 0.001).

CONCLUSION

A satisfactory SFR with a relatively low complication rate was achieved by the relocation technique during the FURS procedure.

Does displacement of lower pole stones during retrograde intrarenal surgery improves stone-free status? A systematic review and meta-analysis

PURPOSE

Kidney stones are one of the most common urological diseases worldwide. The size and location of the stone are the most important factors in determining the most suitable treatment options. The aim of this review was to evaluate the displacement of lower pole stones.

METHODS

Three studies assessing the efficacy of translocating kidney stones from the lower pole of the kidney to other locations during retrograde intrarenal surgery published in the last 20 years were included. A systematic search was conducted in the PubMed, Embase, Latin American and Caribbean Health Sciences Literature (LILACS), and Web of Science databases using the following search terms: "Lower pole," "Lithotripsy." Meta-analysis was performed using Review Manager version 5.4.

RESULTS

Stone-free rates were improved through displacement (odds ratio - OR = -0.15; 95% confidence interval-95%CI -0.24--0.05; p = 0.002; I2 = 21%), but at the cost of increased surgical duration (mean difference = -12.50; 95%CI -24.06--0.95; p = 0.03; I2 = 94%). Although this represents a potentially negative outcome, the improvement in clearance rates justifies the additional investment of time and effort.

CONCLUSIONS

Displacement of lower pole kidney stones for subsequent lithotripsy brings significant benefits in terms of stone-free rate, with no difference in laser energy usage. However, it results in increased surgical time. Despite these factors, the benefits to patients undergoing the procedure are substantial.

A Comparative Study on Outcomes of Retrograde Intrarenal Surgery (RIRS), Mini Percutaneous Nephrolithotomy (PCNL), and Extracorporeal Shock Wave Lithotripsy (ESWL) for Lower Pole Renal Calculi of < 1.5 cm

Background: Percutaneous nephrolithotomy (PCNL), established in the 1970s, has replaced open surgery for large stones. Extracorporeal shock wave lithotripsy (ESWL), once the preferred first-line treatment for small-to-medium-sized renal stones, has a questionable charm owing to patient reluctance for repeated treatments and hospitalizations since ESWL has a reduced stone-free rate (SFR). Flexible ureterorenoscopy, also referred to as RIRS, originally applied in the management of lower pole stones resistant to ESWL, is increasingly being used as a primary modality to manage lower pole stones, and it may potentially achieve higher SFR than ESWL and lower morbidity than PCNL for patients with low-volume stone diseases. Objectives: Observations were made to compare ESWL, mini PCNL, and RIRS in managing lower pole renal calculi of < 1.5 cm. Methods: This observational study encompassed all patients with lower pole renal stones with < 1.5 cm diameter and < 1000 HU density who underwent mini PCNL, RIRS, or ESWL from January 2020 to July 2021. There were 40, 60, and 60 patients in the RIRS, mini PCNL, and ESWL groups, respectively, for all of whom preoperative CT urogram was performed. The patients were informed of the procedures, and their informed consent was obtained. The stone-free rates of the three modalities were compared, and the outcomes were statistically analyzed. Results: The mean stone sizes in the present study were 12.99 × 3.56 mm in mini PCNL, 10.62 × 2.51 mm in RIRS, and 10.93 × 3.13 mm in ESWL. The mini PCNL group's SFR was significantly higher than those of other groups: 59 (98.3%) in mini PCNL, 34 (85%) in RIRS, and 46 (76.7%) in ESWL (P = 0.002). Out of the 60 patients in the mini PCNL group, only one (1.7%) required an ancillary procedure, while only six (10%) out of 40 patients in the RIRS group and 11 (18.33%) out of 60 patients in the ESWL group required the ancillary procedure (P = 0.031). Conclusions: For lower pole renal calculi < 1.5 cm, mini PCNL has the highest SFR, followed by RIRS and ESWL, in sequence. The ancillary procedure rate was 18.33% in the ESWL group, which was higher than those of mini PCNL (1.7%) and RIRS (10%).

The efficacy of retrograde intra-renal surgery (RIRS) for lower pole stones: results from 2946 patients

PURPOSE

To evaluate the perioperative outcomes of retrograde intra-renal surgery (RIRS) for lower pole stones (LPS) and factors affecting stone-free rate (SFR).

METHODS

Data from 20 centers were retrospectively reviewed. Inclusion criteria were adult patients, normal renal anatomy, and LPS. Exclusion criteria were bilateral surgery, concomitant surgery for ureteral stones. SFR was defined as a single residual fragment (RF) ≤ 2 mm and evaluated 3-months after surgery. A multivariable logistic regression analysis was performed to assess factors associated with RF. Statistical significance was set at p value < 0.05.

RESULTS

2946 patients were included. Mean age and stone size were 49.9 years 10.19 mm, with multiple LPS in 61.1% of cases. Total operation and laser time were 63.89 ± 37.65 and 17.34 ± 18.39 min, respectively. Mean hospital stay was 3.55 days. Hematuria requiring blood transfusion and fever/urinary infections requiring prolonged antibiotics occurred in 6.1% and 169 5.7% of cases, while sepsis with intensive-care admission in 1.1% of patients. On multivariate analysis, Multiple stones (OR 1.380), stone size (OR 1.865), and reusable ureteroscopes (OR 1.414) were significantly associated with RF, while Thulium fiber laser (TFL) (OR 0.341) and pre-stenting (OR 0.750) were less likely associated with RF.

CONCLUSIONS

RIRS showed safety and efficacy for LPS with a mean diameter of 10 mm. This procedure can achieve a satisfactory SFR in pre-stented patients with a single and smaller stone, particularly with TFL use.

Unfavorable factors in accessing the pelvicalyceal system during retrograde flexible ureteroscopy (fURS)

Flexible ureteroscopy (fURS) is a well-established procedure for treating multiple upper-urinary tract pathologies, particularly renoureteral lithiasis. Endoscopes have undergone significant advancements, including miniaturization, improved optics, and increased maneuverability. In addition, advancements in accessory instruments, such as the performance of laser fibers, guidewires, and extraction probes, have played a significant role in improving the overall performance of flexible ureteroscopy procedures. However, despite these advancements, unique circumstances can make achieving optimum results during flexible ureteroscopy challenging. These include congenital renal anomalies (horseshoe kidneys, ectopic kidneys, rotation anomalies), as well as the unique intrarenal anatomy (infundibulopelvic angle, infundibular length) or the specifications of the endoscope in terms of maneuverability (active and passive deflection). This review explored challenging scenarios during flexible ureteroscopy procedures in the pyelocaliceal system.

Retrograde intrarenal surgery for lower pole stones utilizing stone displacement technique yields excellent results

Objective

To evaluate the long-term stone-free rate (SFR) of retrograde intra-renal surgery (RIRS) in the treatment of lower pole renal calculi using only basket relocation and identify independent predictors of stone-free status.

Methods

All consecutive patients undergoing RIRS lower pole renal calculi at a single high-volume tertiary center were analyzed retrospectively. Lower pole stones were relocated to the upper pole, where laser lithotripsy was performed. All patients were followed up in the clinic following the surgery and yearly thereafter. The stone-free status was assessed with a combination of an abdominal ultrasound and abdominal X-ray, or an abdominal non-contrast computed tomography if the stones were known to be radiolucent.

Results

A total of 480 consecutive patients who underwent RIRS for treatment of lower pole renal calculi, between January 2012 and December 2018, were analyzed from a prospectively maintained database of 3000 ureteroscopies. With a median follow-up time of 18.6 months, the mean SFR was 94.8%. The procedures were unsuccessful in 26 (5.4%) patients due to unreachable stones. The median stone size of the unreachable stones was 12 mm (range 10-30 mm). Multivariable logistic regression analysis revealed two predictors of SFR for lower pole stones: a small cumulative stone burden (odds ratio [OR]: 0.903, 95% confidence interval [CI]: 0.867-0.941, p<0.0001) and preoperative ureteral stent insertion (OR: 0.515, 95% CI: 0.318-0.835, p=0.007).

Conclusion

The long-term SFR of RIRS for the treatment of lower pole stones with basket displacement with appropriate patient selection is high.

Retrograde Intrarenal Surgery Versus Miniaturized Percutaneous Nephrolithotomy for Kidney Stones >1cm: A Systematic Review and Meta-analysis of Randomized Trials

CONTEXT

Although miniaturized percutaneous nephrolithotomy (mPCNL) and retrograde intrarenal surgery (RIRS) are both options for treating >1cm kidney stones, controversies exist on whether one is more effective and safer than the other.

OBJECTIVE

To systematically appraise randomized trials comparing the effectiveness and safety of mPCNL and RIRS for treating >1cm kidney stones.

EVIDENCE ACQUISITION

A systematic search on PubMed/Medline, Web of Science, Embase, and ClinicalTrials.gov was conducted in August 2020 following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). Randomized trials comparing mPCNL and RIRS for >1cm kidney stones, and reporting stone-free rate (SFR), hemoglobin drop, transfusion rate, length of hospital stay (LOS), and/or complications, were included.

EVIDENCE SYNTHESIS

Eight studies compared mPCNL and RIRS, but one was not included due to its high risk of bias. SFR was higher for mPCNL (RR: 1.06 [95% coefficient interval {CI}, 1.01-1.10], p=0.008). Hemoglobin drop was higher for mPCNL (mean difference [MD]: 0.35 [95% CI, 0.05-0.65] g/dl, p=0.02); however, transfusion rates were similar (p=0.44). Complication rate was similar between mPCNL and RIRS (p=0.39), and the LOS was higher for mPCNL (MD: 1.11 [95% CI, 0.06-2.16] d, p=0.04). A subgroup analysis of lower pole stones showed that SFR was higher for mPCNL (RR: 1.09 [95% CI, 1.00-1.19], p=0.05).

CONCLUSIONS

Both approaches are effective and safe. Among these approaches, mPCNL has a higher SFR than RIRS for overall >1cm renal and lower pole stones, but longer LOS, and a higher hemoglobin drop that does not translate into higher transfusion rates. Complications are comparable.

PATIENT SUMMARY

Randomized trials have evaluated whether miniaturized percutaneous nephrolithotomy (mPCNL) or retrograde intrarenal surgery is more effective and safer for treating >1cm stones. After comparing the stone-free rate, hemoglobin drop, transfusion rate, length of hospital stay, and complications between both the approaches, mPCNL was found to be slightly more effective, but both were equally safe.

Effect of Preoperative Double-J Ureteral Stenting before Flexible Ureterorenoscopy on Stone-free Rates and Complications

The effect of preoperative Double-J (DJ) ureteral stenting before flexible ureterorenoscopy (FURS) in the treatment for urinary stones was evaluated. We retrospectively enrolled 306 consecutive patients who underwent FURS from Jan. 2014 to Dec. 2017. All the patients were classified into two groups according to whether they had DJ ureteral stenting before FURS. Baseline characteristics (age, sex, stone location, stone size, surgical success rate, operation time, stone-free rate of the first day after surgery, stone-free rate of the first month after surgery, total complication rate) were compared using Chi-square test for categorical variables and Kruskal-Wallis test for continuous variables. In total, 306 patients were included in this study. The group of DJ stenting before FURS included 203 (66.3%) patients, and non-DJ stenting before FURS was observed in 103 (33.7%) patients. The group of DJ stenting before FURS was significantly associated with a shorter operation time (53.8 vs. 59.3 min, P<0.001), a higher stone-free rate of the first day after surgery (69.0% vs. 51.5%, P=0.003). However, statistical significant differences were not found in the age, sex, stone location, stone size, surgical success rate, stone-free rate of the first month after surgery (89.2% vs. 81.6%, P=0.065) and total complication rate (5.4% vs. 9.7%, P=0.161) between the two groups. Preoperative DJ ureteral stenting before FURS could reduce the operation time and increase stone-free rate of the first day after surgery. However, it might not benefit the stone-free rate of the first month after surgery and reduce the complication rate. Preoperative DJ stenting should be not routinely performed.

Consultation on kidney stones, Copenhagen 2019: aspects of intracorporeal lithotripsy in flexible ureterorenoscopy

Purpose

To summarize current knowledge on intracorporeal laser lithotripsy in flexible ureterorenoscopy (fURS), regarding basics of laser lithotripsy, technical aspects, stone clearance, lithotripsy strategies, laser technologies, endoscopes, and safety.

Methods

A scoping review approach was applied to search literature in PubMed, EMBASE, and Web of Science. Consensus was reached through discussions at the Consultation on Kidney Stones held in September 2019 in Copenhagen, Denmark.

Results and conclusions

Lasers are widely used for lithotripsy during fURS. The Holmium laser is still the predominant technology, and specific settings for dusting and fragmenting have evolved, which has expanded the role of fURS in stone management. Pulse modulation can increase stone ablation efficacy, possibly by minimizing stone retropulsion. Thulium fibre laser was recently introduced, and this technology may improve laser lithotripsy efficiency. Small fibres give better irrigation, accessibility, and efficiency. To achieve optimal results, laser settings should be adjusted for the individual stone. There is no consensus whether the fragmentation and basketing strategy is preferable to the dusting strategy for increasing stone-free rate. On the contrary, different stone scenarios call for different lithotripsy approaches. Furthermore, for large stone burdens, all laser settings and lithotripsy strategies must be applied to achieve optimal results. Technology for removing dust from the kidney should be in focus in future research and development. Safety concerns about fURS laser lithotripsy include high intrarenal pressures and temperatures, and measures to reduce both those aspects must be taken to avoid complications. Technology to control these parameters should be targeted in further studies.

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

PURPOSE

To critically review all literature concerning the cost-effectiveness of flexible ureteroscopy comparing single-use with reusable scopes.

MATERIALS AND METHODS

A systematic online literature review was performed in PubMed, Embase and Google Scholar databases. All factors potentially affecting surgical costs or clinical outcomes were considered. Prospective assessments, case control and case series studies were included.

RESULTS

741 studies were found. Of those, 18 were duplicated and 77 were not related to urology procedures. Of the remaining 646 studies, 59 were considered of relevance and selected for further analysis. Stone free and complication rates were similar between single-use and reusable scopes. Operative time was in average 20% shorter with digital scopes, single-use or not. Reusable digital scopes seem to last longer than optic ones, though scope longevity is very variable worldwide. New scopes usually last four times more than refurbished ones and single-use ureterorenoscopes have good resilience throughout long cases. Longer scope longevity is achieved with Cidex and if a dedicated nurse takes care of the sterilization process. The main surgical factors that negatively impact device longevity are lower pole pathologies, large stone burden and non-use of a ureteral access sheath. We have built a comprehensive fi nancial costeffective decision model to fl exible ureteroscope acquisition.

CONCLUSIONS

The cost-effectiveness of a fl exible ureteroscopy program is dependent of several aspects. We have developed a equation to allow a literature-based and adaptable decision model to every interested stakeholder. Disposable devices are already a reality and will progressively become the standard as manufacturing price falls.

Comparison of stone-free rates following shock wave lithotripsy, percutaneous nephrolithotomy, and retrograde intrarenal surgery for treatment of renal stones: A systematic review and network meta-analysis

OBJECTIVES

To perform a systematic review and network meta-analysis comparing stone-free rates following retrograde intrarenal surgery (RIRS), extracorporeal shock wave lithotripsy (SWL), and percutaneous nephrolithotomy (PCNL) treatments of renal stones.

MATERIALS AND METHODS

Clinical trials comparing RIRS, SWL, and PCNL for treatment of renal stones were identified from electronic databases. Stone-free rates for the procedures were compared by qualitative and quantitative syntheses (meta-analyses). Outcome variables are shown as risk ratios (ORs) with 95% credible intervals (CIs).

RESULTS

A total of 35 studies were included in this network meta-analysis of success and stone-free rates following three different treatments of renal stones. Six studies compared PCNL versus SWL, ten studies compared PCNL versus RIRS, fourteen studies compared RIRS versus SWL, and five studies compared PCNL, SWL, and RIRS. The quality scores within subscales were relatively low-risk. Network meta-analyses indicated that stone-free rates of RIRS (OR 0.38; 95% CI 0.22-0.64) and SWL (OR 0.12; 95% CI 0.067-0.19) were lower than that of PCNL. In addition, stone-free rate of SWL was lower than that of RIRS (OR 0.31; 95% CI 0.20-0.47). Stone free rate of PCNL was also superior to RIRS in subgroup analyses including ≥ 2 cm stone (OR 4.680; 95% CI 2.873-8.106), lower pole stone (OR 1.984; 95% CI 1.043-2.849), and randomized studies (OR 2.219; 95% CI 1.348-4.009). In rank-probability test, PCNL was ranked as No. 1 and SWL was ranked as No. 3.

CONCLUSIONS

PCNL showed the highest success and stone-free rate in the surgical treatment of renal stones. In contrast, SWL had the lowest success and stone-free rate.

The role of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS)

To assess the safety and efficacy of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS), we retrospectively evaluated 44 patients with symptomatic LPSs with previously failed SWL or RIRS and consequently underwent SMP from October 2014 to March 2016. The percutaneous renal access was performed 12-14F with C-arm fluoroscopy or ultrasonographic guidance. Stone disintegration was performed using either Holmium laser or pneumatic lithotripter. Perioperative parameters along with operations were assessed in detail. A total of 44 patients (mean age 49.1 ± 13.7 years) were included in the study. Stone size was 18.4 ± 6.0 mm (range 9-29), operative time was 63.9 ± 32.7 min (range 14-145) and hospital stay was 2.8 ± 1.2 days (range 1-5). The hemoglobin drop was 12.4 ± 8.8 g/L (range 0-31), and no patients required blood transfusion. Complete stone-free status was achieved in 40 (90.9%) patients. Clinically insignificant residual fragments were observed in three (6.8%) patients and only one (2.3%) patient had a 6 mm residual calculus. A total of three minor complications (urinary tract infection, hemorrhage resolved by hemostatics and renal colic requiring analgesics) were observed postoperatively. For symptomatic LPSs after the failure of SWL or RIRS, SMP is a safe and efficient auxiliary option and even might be an alternative to SWL or RIRS, while further considering the stone-free rates and stone-related events.

Nephrolithiasis in a 17-Year-Old Male With Seckel Syndrome and Horseshoe Kidneys: Case Report and Review of the Literature

We report the case of a 17-year-old male with Seckel syndrome and horseshoe kidneys which had a 7 mm kidney stone in the lower pole calyx of the right moiety. The patient had a history of rotoscoliosis with 60° dextroconvex curvature and hepatic steatosis. Attempted ureteroscopy was unsuccessful due to stone location and anatomy. Percutaneous nephrolithotomy was ultimately required. This case highlights the difficulties of endoscopic treatments of renal calculi in patients with abnormal renal anatomy and dysmorphia. To our knowledge, this is the first reported case of nephrolithiasis in a patient with Seckel syndrome and horseshoe kidneys.

Comparison of flexible ureteroscopy damage rates for lower pole renal stones by laser fiber type

OBJECTIVES

Laser lithotripsy, often used during ureteronephroscopy (URNS), requires the Ho:YAG optical fiber transmit energy via total internal reflection (TIR). In critical lower pole deflections, energy may refract into the cladding causing fiber failure and scope damage. New optical fiber technology aims to have increased tolerance for high degrees of flexion. We compared two brands of laser fibers with sub-300 micron cores (Sureflex, Boston Flexiva) to determine failure rates and scope repair costs.

METHODS

A retrospective cohort study comparing these two fibers for patients at a single academic institution who underwent flexible URNS with laser lithotripsy was performed from September 2013 to October 2015. Preoperative imaging was evaluated for stone burden and location. Intraoperative variables were collected, including energy use, lower pole lasering, laser fiber malfunction, and scope damage. The primary outcome was scope damage caused by laser fiber malfunction. Secondary outcome was scope repair costs. Fisher's exact test and two tailed t-tests were used.

RESULTS

Of 223 subjects, 143 met inclusion criteria, and 8 had laser fiber failure. All failures occurred with the Sureflex fiber (8 of 63, 13%) vs the Boston Flexiva fiber (0 of 80, 0%) (P < 0.01). Malfunctions occurred in 8 of 79 lower pole stone applications versus 0 of 64 non-lower pole stone laser applications (P < 0.01). No other risk factor was different between fiber cohorts, except energy setting. Scope repair cost averaged $9155 CDN, yielding an average repair cost per case of $1144 CDN for the Sureflex versus $0 for the Boston fiber (P < 0.01).

CONCLUSIONS

Both optical fibers perform well in non-lower pole locations. However, the challenge for laser fibers in lower pole URNS is to maintain TIR. Fiber failure reflects an inability to maintain reflection and is not based on energy used or stone burden. The Boston Flexiva laser fiber has fewer failures, resulting in $0 repair cost per case, compared to the Sureflex fiber in URNS with an average repair cost of $1144 CDN per case. Lasers Surg. Med. 50:798-801, 2018. © 2018 Wiley Periodicals, Inc.

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.

Flexible ureteroscopy: Technological advancements, current indications and outcomes in the treatment of urolithiasis

The last 3 decades have witnessed great improvements in the technology and clinical applications of many minimally invasive procedures in the urological field. Flexible ureteroscopy (fURS) has advanced considerably to become a widely utilized diagnostic and therapeutic tool for multiple upper urinary tract pathologies. The most common indication for fURS is the treatment of upper urinary tract stones with the aid of Holmium:Yttrium Aluminium Garnet (YAG) laser lithotripsy. Advancements in endoscope technologies and operative techniques have lead to a broader application of fURS in the management of urolithiasis to include larger and more complex stones. fURS has proved to be an effective and safe procedure with few contraindications. Continued progression in fURS may increase its clinical applicability and supplant other procedures as the first line treatment option for urolithiasis.

Comparison between retrograde intrarenal surgery and extracorporeal shock wave lithotripsy in the treatment of lower pole kidney stones up to 15 mm. Prospective, randomized study

INTRODUCTION

Extracorporeal Shock Wave Lithotripsy (ESWL) is currently the recommended treatment for intra-renal calculi smaller than 2 cm. However the low Stone Free Rate (SFR) in lower pole calculi gives rise to new techniques, such us retrograde intrarenal surgery (RIRS), for improve the surgery outcomes.

OBJECTIVE

To compare the efficacy of a treatment with ESWL with RIRS, in terms of SFR after surgery, in patients with kidney stones up to 15 mm in the lower pole.

MATERIAL AND METHODS

A prospective study was carried out in order to assess the results of ESWL and RIRS in patients with lower pole stones less than 15 mm. Among a total of 55 patients, 31 were underwent to ESWL (Group 1) and the remaining 24 to RIRS (Group 2). Clinical data recorded, including general characteristics of each patient, were: calculi size, side, operative time, complications according to Clavien scale, SFR and the presence of residual fragments at 2 months post-treatment assessed by a CT scan. STATA 11 was used to perform the statistical analysis.

RESULTS

There were no differences for general descriptors among groups with the exception of a significantly longer operative time for RIRS. The rates of SFR and residual fragments lesser than 3 mm. were lower in the RIRS group than in ESWL ones. RIRS also showed a lower rate of clinically significant fragments (0% vs 42.3%. P < .05). In the subgroup of patients with stones between 10/15 mm RIRS showed higher SFR (75% vs. 41.2%) and a lower rate of stones>3 mm (0% vs. 58.8%), being statistically significant (P < .05). Clavien III or higher complications were not reported in any of the groups.

CONCLUSIONS

In the treatment of lower pole stone RIRS has the same results than ESWL in terms of SFR. Regarding absence of a clinically significant residual fragment, RIRS was superior to ESWL. A bigger sample size is required in order to confirm this results.

Flexible Ureterorenoscopy versus Extracorporeal Shock Wave Lithotripsy for the treatment of upper/middle calyx kidney stones of 10-20 mm: a retrospective analysis of 174 patients

To compare the outcomes of flexible ureterorenoscopy (F-URS) with extracorporeal shock wave lithotripsy (ESWL) for the treatment of upper or mid calyx kidney stones of 10 to 20 mm.

A total of 174 patients with radioopaque solitary upper or mid calyx stones who underwent ESWL or F-URS with holmium:YAG laser were enrolled in this study. Each group treated with ESWL and F-URS for upper or mid calyx kidney stones were retrospectively compared in terms of retreatment and stone free rates, and complications.

87% (n = 94) of patients who underwent ESWL therapy was stone free at the end of 3rd month. This rate was 92% (n = 61) for patients of F-URS group (p = 0.270 p > 0.05). Retreatment was required in 12.9% of patients (n = 14) who underwent ESWL and these patients were referred to F-URS procedure after 3rd month radiologic investigations. The retreatment rate of cases who were operated with F-URS was 7.5% (n = 5) (p = 0.270 p > 0.05). Ureteral perforation (Clavien grade 3B) was occured in 3 patients (4.5%) who underwent F-URS. Fever (Clavien grade 1) was noted in 7 and 5 patients from ESWL and F-URS group, respectively (6.4% vs 7.5%) (p = 0.78 p > 0.05).

F-URS and ESWL have similar outcomes for the treatment of upper or mid calyx renal stones of 10–20 mm. ESWL has the superiority of minimal invasiveness and avoiding of general anethesia. F-URS should be kept as the second teratment alternative for patients with upper or mid caliceal stones of 10–20 mm and reserved for cases with failure in ESWL.

Efficacy of flexible ureteroscopy and laser lithotripsy for lower pole renal calculi

Objective:

Our aim was to determine whether flexible ureterorenoscopy and laser lithotripsy is efficacious and safe in treating lower pole renal calculi.

Materials and methods:

Patient, procedure and stone data of patients who underwent flexible ureterorenoscopy and laser lithotripsy at our referral centre were collected prospectively between November 2005 and November 2011 and entered into a designated database. In all, 242 procedures were performed in 198 patients.

Results:

The mean age was 51.2 years. The mean calculi size was 10.51 mm (range 4–27 mm). Thirty seven patients had more than one stone in the lower pole. An access sheath was used in 19 patients (9.6%), 171 (86.4%) had a ureteric stent inserted after the procedure, and 165 patients had a single procedure. Re-operation rate was 16.7%. Stone-free rates after one procedure were 89%, 80% and 41%, respectively, for calculi measuring 4–10 mm ( n=107), 11–20 mm ( n=76) and > 20 mm ( n=15). The overall stone-free rate was 83%, 91% and 95% after one, two and three procedures, respectively.

Conclusion:

Flexible ureterorenoscopy and laser lithotripsy is a safe and effective minimally invasive treatment option for patients with 4–20 mm lower pole calculi. Staged procedures, however, become necessary as the size of the stone increases greater than 20 mm, and this should be mentioned when counselling patients for their primary procedure.

[Calyceal stones]

The natural course of untreated, asymptomatic calyceal calculi has not yet been clearly defined regarding disease progression and risk of surgical interventions. The decision for an active treatment of calyceal calculi is based on stone composition, stone size and symptoms. Extracorporeal shockwave lithotripsy (ESWL) has a low complication rate and is recommended by the current guidelines of the German (DGU) and European (EAU) Associations of Urology as a first-line therapy for the treatment of calyceal stones <2 cm in diameter. However, immediate removal of stones is not achieved with ESWL. The primary stone-free rates (SFR) after ESWL depend on stone location and stone composition and can show remarkable differences. Minimally invasive procedures, such as percutaneous nephrolitholapaxy and ureteroscopy are alternatives for the treatment of calyceal stones which have low morbidity and high primary SFR when performed in centres of excellence.

Intracorporeal laser lithotripsy

Objectives

To review the current literature on intracorporeal laser lithotripsy.

Methods

We searched PubMed for relevant reports up to January 2012, using the keywords ‘laser’, ‘lithotripsy’ and ‘intracorporeal’.

Results

We studied 125 relevant reports of studies with various levels of evidence. Efficient lithotripsy depends on the laser variables (wavelength, pulse duration and pulse energy) and the physical properties of the stones (optical, mechanical and chemical). The most efficient laser for stones in all locations and of all mineral compositions is the holmium yttrium–aluminium–garnet laser (Ho:YAG). The frequency-doubled double-pulse Nd:YAG laser functions through the generation of a plasma bubble. New laser systems, such as the erbium:YAG and the thulium laser, are under evaluation. Laser protection systems have also been developed for the novel digital flexible ureteroscopes. Although complications are rare, a high relevant clinical suspicion is necessary.

Conclusions

Laser lithotripsy technology is continuously developing, while the Ho:YAG laser remains the reference standard for intracorporeal lithotripsy.

Flexible ureterorenoscopy versus extracorporeal shock wave lithotripsy for treatment of lower pole stones of 10-20 mm

What's known on the subject? and What does the study add? Shock wave lithotripsy and flexible ureterorenoscopy are acceptable treatment options for lower pole stones smaller than 10 mm, while percutaneous nephrolithotomy is the favoured treatment for stones larger than 20 mm. For treatment of lower pole stones of 10-20 mm, flexible ureterorenoscopy has a significantly higher stone-free rate and lower retreatment rate than shock wave lithotripsy.

OBJECTIVE

To compare the outcomes of flexible ureterorenoscopy (F-URS) and extracorporeal shock wave lithotripsy (ESWL) for treatment of lower pole stones of 10-20 mm.

PATIENTS AND METHODS

The database of patients with a single lower pole stone of 10-20 mm was examined to obtain two matched groups who were treated with F-URS or ESWL. Matching criteria were stone length, side and patient gender. Stone-free rates were evaluated 3 months after the last treatment session by non-contrast computed tomography. Both groups were compared for retreatment rate, complications and stone-free rate.

RESULTS

The matched groups included 37 patients who underwent F-URS and 62 patients who underwent ESWL. Retreatment rate was significantly higher for ESWL (60% vs 8%, P < 0.001). Complications were more after F-URS (13.5% vs 4.8%), but the difference was not significant (P= 0.146). All complications were grade II or IIIa on modified Clavien classification. The stone-free rate was significantly better after F-URS (86.5% vs 67.7%, P= 0.038). One failure of F-URS (2.7%) and five failures (8%) of ESWL were treated with percutaneous nephrolithotomy. Significant residual fragments in three patients (8%) after F-URS were treated with ESWL, while significant residual fragments after ESWL in five patients (8%) were treated with F-URS. Residual fragments (<4 mm) were followed every 3 months in one patient (2.7%) after F-URS and in 10 patients (16%) after ESWL.

CONCLUSIONS

For treatment of lower pole stones of 10-20 mm, F-URS provided significantly higher stone-free rate and lower retreatment rate compared with ESWL. The incidence of complications after F-URS was not significantly more than after ESWL.

[Controversy on lower pole stones: monitor or intervene?]

For many years, the treatment options of lower pole stones have been discussed controversially: Watchful waiting, shock wave lithotripsy, flexible ureterorenoscopy and percutaneous litholapaxy. Small lower pole stones <1 cm can be monitored actively. Shock waves can disintegrate the stones and are recommended for stones <1 cm. However, the stone-free rate is limited because of the particular anatomy of the lower pole. Modern flexible ureterorenoscopes can nowadays reach even anatomically unfavourable lower calyxes. For stones <1 cm good stone-free results can be achieved. For larger stones >2 cm percutaneous nephrolithotomy (PNL) is the standard treatment modality.

[Retrograde intrarenal surgery (RIRS). Technical complement for cases of acute lithiasis]

INTRODUCTION

Washing the renal cavities using minipercutaneous surgery shaft is an ideal technical procedure for retrograde intrarenal surgery (RIRS) when lithiasic fragmentation is significant or if the anatomy of the renal cavities may obstruct the spontaneous elimination of fragments.

MATERIALS AND METHODS

we performed 37 RIRS on 35 patients with renal lithiasis (14 men, 21 women) with a mean age of 56 (range 33-72) years, divided into two groups in accordance with the size of their kidney stones. Group A, 23 patients with lithiasis <1.5 cm; Group B, 12 cases with lithiasis >1.5 cm. 28 patients had a single kidney stone and 7 had multiple stones.

APPROACH

Flexible uretrorenoscopy, 7.5 Fr (Flex-X(®, Karl Storz) by means of a ureteral access sheath. Holmium laser lithotripsy (Calculase®, Karl Storz) using 200 and 365 micrometer fibres. Fragment extraction with 1.7 Fr nitinol baskets (N-gage, Cook). In cases of significant fragmented stone burden, the renal cavities were washed with low-pressure fluid irrigation using a ureteral access sheath, which was collected together with the stone fragments carried by the "mini-perc" sheath (Ultrax-x® 18Fr, Cook; Rusch, 14 Fr) placed under radiologic and endoscopic control at the level of the calyx-papilla selected for fragment drainage.

RESULTS

the mean diameter for group A was 9.13 (range 5-13) mm and 20.25 (range 16-28) mm for group B. The overall mean operating time was 81 (range 30-160) min. Group A required 66.43±35.18 min. and group B 107.5±46.73 min. (p=0.006). The rate of absence of stones immediately after surgery was 83.2%, 93.1% at 3 months (95.6% for A and 83.3% for B; p=0.217). In no case was ureteral stenosis observed as a result of the use of ureteral access sheaths. In 7 group B patients (58.3%) with acute lithiasis and/or alteration in their pyelocaliceal anatomy, we performed active lavage of the renal cavities applying the aforementioned percutaneous technique. The mean post-surgery hospital stay was 2.1 (range 1-4) days. There were post-surgery complications (Clavien 1) in 7 patients (20%). Two patients required a second FURS.

CONCLUSIONS

RIRS can be effective treatment for renal lithiasis >1.5 cm. Lavage of the renal cavities helps to eliminate stone fragments, reducing the possibility of retreatment.

Lower calyceal occlusion by autologous blood clot to prevent stone fragment reaccumulation after retrograde intra-renal surgery for lower calyceal stones: first experience of a new technique

PURPOSE

We tested the hypothesis that lower calyceal (LC) autologous blood clot (ABC) occlusion, after retrograde intra-renal surgery (RIRS) may prevent LC fragment reaccumulation where all fragments cannot be directly removed.

METHODS

Over two years, patients with LC stones >6 mm <2 cm, that had presented de-novo or failed primary SWL or PNL elsewhere, were treated with RIRS. After intra-renal relocation into a favorable lie, stones were fragmented with Holmium laser energy to <3 mm, suitable for spontaneous passage. The LC was filled with 5-10 cc venous autologous blood with the patient in reverse Trendelenberg, leaving the blood to clot. After confirmatory pyelogram a DJ stent was placed. Ultrasound and KUB at 3 months assessed stone free rate.

RESULTS

This technique was tested in 35 patients with LC calculi (16 as primary treatment, and 19 as salvage for residual fragments post SWL or PNL). Nine salvage patients had indwelling DJ stents (three significantly encrusted at RIRS). Nine unstented patients had upper ureteral tortuosities or narrowing limiting multiple instrument passes for stone removal. Median maximum stone dimension was 1.2 cm. All were successfully relocated & fragmented. A Nitinol basket was required for stone relocation in 60%. All but one occlusion procedures succeeded at the first attempt. None required re-admission for clot colic. Only 8.6% required more than overnight hospital stay. Three and six month stone free rates were 94% and 97% respectively.

CONCLUSIONS

The simple LC autologous blood clot occlusion technique after RIRS, for difficult LC stones, validates our hypothesis and results in excellent stone free rates, while minimizing ureteral trauma from multiple instrument passages needed for active fragment removal. This study supports the need for multi-center experience of this technique to validate our results.

Management options for lower pole renal calculi

PURPOSE OF REVIEW

The optimal treatment of lower pole renal calculi is controversial. Shock wave lithotripsy, ureteroscopy and percutaneous nephrostolithotomy all constitute viable therapeutic options in select patients.

RECENT FINDINGS

Lower pole stones smaller than 1 cm in diameter can be managed with observation, shock wave lithotripsy or ureteroscopy. Patients electing expectant management should be counseled regarding the potential for stone-related symptom progression and need for future intervention. Shock wave lithotripsy and ureteroscopy have similar stone-free rates, although shock wave lithotripsy may be preferable due to more favorable secondary outcomes. Lower pole stones 1-2 cm in diameter are best managed with percutaneous nephrostolithotomy, although ureteroscopy is an option in select patients, particularly those not considered candidates for percutaneous nephrostolithotomy. Finally, patients with lower pole stones larger than 2 cm are best served with percutaneous nephrostolithotomy, as the morbidity in experienced hands is low and stone-free rates are unequivocally higher than those of other treatment modalities.

SUMMARY

A variety of factors, including patient body habitus, local renal anatomy, cost and patient preference, must be taken into consideration when determining the optimal treatment modality for lower pole renal calculi.

A case of a lower pole renal calculus managed with percutaneous nephrolithotomy

BACKGROUND

A 50-year-old man presented to an outpatient urology clinic with left-sided flank pain. He had received treatment for a left renal pelvis calculus 5 years earlier; shock wave lithotripsy had been unsuccessful and ureteroscopic laser lithotripsy had left the patient with a 2 mm residual stone fragment. The fragment was deemed clinically insignificant, and the patient remained asymptomatic without any further follow-up.

INVESTIGATIONS

Physical examination, CT of the abdomen and pelvis, and complete metabolic evaluation.

DIAGNOSIS

Left lower pole renal calculus and idiopathic hypercalciuria.

MANAGEMENT

The patient was counseled about his treatment options, and he elected to undergo percutaneous nephrolithotomy. After a single-stage procedure, CT confirmed a stone-free state. The patient was administered thiazide therapy and dietary counseling to treat his hypercalciuria. This condition resolved, and the patient remained stone-free 1 year after treatment.

Advances in ureterorenoscopy

There has been a shift toward minimally invasive surgery in all surgical subspecialties in recent decades. Ureterorenoscopy represents an area in which there have been numerous advances that have resulted in excellent patient outcomes with low morbidity. Technologic advances such as miniaturization of ureteroscopes and improved video imaging have expanded the indications for ureteroscopy. The entire upper urinary tract can now be accessed for diagnosis and treatment of many common urologic conditions. Technologic research and development will continue to drive future improvements in the technique and applications for ureteroscopy.

Treatment Selection and Outcomes: Renal Calculi

This article summarizes the history of how renal stones have been treated over the centuries and reviews current treatments and outcomes for renal stones. The authors provide an algorithm based on available outcome data for shock wave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy.