Flexible Ureterorenoscopy for Renal and Proximal Ureteral Stone in Patients with Previous Ureteral Stenting: Impact on Stone-Free Rate and Morbidity

Effect of perioperative tamsulosin on successful ureteral access sheath placement and stent-related symptom relief: A double-blinded, randomized, placebo-controlled study

PURPOSE

This study investigated the effect of administering tamsulosin before surgery on the successful insertion of a 12/14 French (F) ureteral access sheath (UAS) during the procedure, as well as the impact of preoperative and postoperative tamsulosin use on symptoms related to the ureteral stent.

MATERIALS AND METHODS

This study was a randomized, single-center, double-blinded, placebo-controlled trial involving 200 patients who underwent unilateral retrograde intrarenal surgery. Patients received either tamsulosin (0.4 mg) or placebo 1 week before surgery until stent removal. Patients were randomly assigned to one of four groups. Group 1 received tamsulosin throughout the study period. Group 2 received tamsulosin before surgery and placebo after surgery. Group 3 received placebo before surgery and tamsulosin after surgery. Group 4 received placebo before and after surgery. The USSQ (Ureteral Stent Symptom Questionnaire) was completed between postoperative days 7 and 14 immediately before stent removal.

RESULTS

A total of 160 patients were included in this analysis. Their mean age was 55.0±11.0 years, and 48 patients (30.0%) were female. In the group that received preoperative tamsulosin, the success rate of 12/14F UAS deployment was significantly higher than that of the preoperative placebo group (88.0 vs. 75.3%, p=0.038). Preoperative and postoperative tamsulosin did not significantly alleviate symptoms related to the ureteral stent.

CONCLUSIONS

Our results revealed that preoperative administration of tamsulosin improved the success of larger-sized UAS, whereas preoperative and postoperative tamsulosin use did not significantly alleviate symptoms related to ureteral stents.

International Alliance of Urolithiasis guideline on retrograde intrarenal surgery

OBJECTIVES

To set out the second in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis that concerns retrograde intrarenal surgery (RIRS), with the aim of providing a clinical framework for urologists performing RIRS.

MATERIALS AND METHODS

After a comprehensive search of RIRS-related literature published between 1 January 1964 and 1 October 2021 from the PubMed database, systematic review and assessment were performed to inform a series of recommendations, which were graded using modified GRADE methodology. Additionally, quality of evidence was classified using a modification of the Oxford Centre for Evidence-Based Medicine Levels of Evidence system. Finally, related comments were provided.

RESULTS

A total of 36 recommendations were developed and graded that covered the following topics: indications and contraindications; preoperative imaging; preoperative ureteric stenting; preoperative medications; peri-operative antibiotics; management of antithrombotic therapy; anaesthesia; patient positioning; equipment; lithotripsy; exit strategy; and complications.

CONCLUSION

The series of recommendations regarding RIRS, along with the related commentary and supporting documentation, offered here should help provide safe and effective performance of RIRS.

Failure of ureteral access sheath insertion in primary flexible ureteroscopy for renal stones: is there any relation with inflammation?

PURPOSE

To investigate the relationship between failure to insert a ureteral access sheath (UAS) with inflammation and other clinical parameters in patients treated with flexible ureteroscopy for renal stones.

METHODS

This study included patients who underwent flexible ureteroscopy for the treatment of renal stones in our centre between 2015 and 2020. Patients who underwent any surgical procedure on the ipsilateral ureter and had a history of spontaneous stone passage were excluded. Patients were divided into two groups based on UAS insertion success (group 1) or failure (group 2). Both groups were compared with a view to clinical characteristics, preoperative neutrophil, lymphocyte, monocyte and platelet counts and ratios of these counts, all being considered inflammatory markers. A multivariate logistic regression analysis was performed to determine the independent variables affecting UAS insertion success.

RESULTS

There were 113 (59.1%) patients in group 1, while group 2 consisted of 78 (40.9%) patients. The rates of male gender, coronary artery disease and preoperative ipsilateral hydronephrosis were significantly higher in group 2, while platelet counts and platelet-lymphocyte ratios were significantly lower. Our analysis revealed four independent predictors for UAS insertion failure: female gender (odds ratio [OR]=2.1) increased the rate of UAS insertion success, while hydronephrosis (OR=1.6), low platelet counts and PLR increased the rate of UAS insertion failure (OR=0.99, OR=0.98, respectively).

CONCLUSION

Our results suggest that male gender and ipsilateral hydronephrosis are associated with increased UAS insertion failure. Although we found a relationship between relatively low platelet levels and UAS insertion failure, we think that further studies are needed to investigate this matter.

Single-Use vs. Reusable Digital Flexible Ureteroscope to Treat Upper Urinary Calculi: A Propensity-Score Matching Analysis

Objective: The purpose of this research was to compare the treatment outcomes and costs of a single-use and reusable digital flexible ureteroscope for upper urinary calculi.

Methods: Four hundred forty patients with reusable digital flexible ureteroscope and 151 patients with single-use flexible digital ureteroscope were included in this study. Through exclusion and inclusion criteria and 1:1 propensity-score matching analysis based on baseline characteristics, ultimately, 238 patients (119:119) were compared in terms of treatment outcomes. The cost analysis was based on the costs of purchase, repair, and reprocessing divided by the number of all procedures in each group (450 procedures with reusable digital flexible ureteroscope and 160 procedures with single-use digital flexible ureteroscope).

Results: There was no statistical significance in mean operation time (P = 0.666). The single-use digital flexible ureteroscope group has a shorter mean length of hospital stay than the reusable digital flexible ureteroscope group (P = 0.026). And the two groups have a similar incidence of postoperative complications (P = 0.678). No significant difference was observed in the final stone-free rate (P = 0.599) and the probability of secondary lithotripsy (P = 0.811) between the two groups. After 275 procedures, the total costs of a single-use flexible ureteroscope would exceed the reusable flexible ureteroscope.

Conclusion: Our data demonstrated that the single-use digital flexible ureteroscope is an alternative to reusable digital flexible ureteroscopy in terms of surgical efficacy and safety for upper urinary calculi. In terms of the economics of the two types of equipment, institutions should consider their financial situation, the number of FURS procedures, the volume of the patient's calculus, surgeon experience, and local dealerships' annual maintenance contract when making the choice.

The Outcomes of Pre-Stenting on Renal and Ureteral Stones: A Meta-Analysis

BACKGROUND

Pre-stenting (PS) on the outcomes of semirigid and flexible ureteroscopic lithotripsy for a different upper urinary urolithiasis remains controversial. We performed a meta-analysis comparing the outcomes of ureteroscopic lithotripsy between PS and non-PS.

MATERIALS AND METHODS

Randomized, controlled trials and observational studies comparing PS and non-PS were identified from electronic databases. Stone-free rate (SFR), operative time, and complications were compared by qualitative and quantitative syntheses (meta-analyses).

RESULTS

Eleven articles were included in this study. Nearly, all of recently published studies exhibited relatively moderate or high quality during quality assessment. PS was more likely to achieve good SFR compared with non-PS (p < 0.00001). The subgroup results indicated that PS improved the SFR for renal stones and the stones dealt by flexible ureteroscopy (p = 0.0002; p < 0.0001, respectively; some ureteral stones were dealt by flexible ureteroscopy). Ureteral stones and the stones dealt by semirigid ureteroscopy were not influenced by PS (p = 0.62; p = 0.90, respectively). PS is equal as non-PS in terms of operative time for renal stones and the renal and ureteral stones dealt by flexible ureteroscopy (p = 0.47; p = 0.05). No significant difference was found in major complications between the 2 groups for total or for the subgroup of renal stones (p = 0.3; p = 0.69).

CONCLUSIONS

For ureteral stones or the stones dealt by semirigid ureteroscopy, PS does not show any benefits. For renal stones or the stones dealt by flexible ureteroscopy, PS improves the SFR and may be as safe as non-PS.

Impact of Preoperative Stenting on the Outcome of Flexible Ureterorenoscopy for Upper Urinary Tract Urolithiasis: A Systematic Review and Meta-Analysis

PURPOSE

This study aimed to investigate the effect of preoperative stenting (POS) on the perioperative outcomes of flexible ureterorenoscopy (fURS).

MATERIALS AND METHODS

A systematic review and meta-analysis was conducted based on the PRISMA statement. From the initially retrieved 609 reports, we excluded the ineligible studies at 2 stages. We only included studies that contained fURS patients with and without POS in the same report. Data of patients who underwent semirigid ureteroscope only were excluded from the analysis. The Newcastle-Ottawa Scale (NOS) system was applied for risk of bias assessment.

RESULTS

A total of 20 studies including 5,852 patients were involved. 48.5% of the patients had preoperative stent. Stone-free rate was significantly higher with prestenting; odds ratio (OR) was 1.98 (95% CI: 1.51-2.58) (Z = 5.02; p = 0.00001). It also displayed tendency toward lower complications; OR was 0.74 (95% CI: 0.52-1.05) (Z = 1.67; p = 0.09). POS significantly increased the use of ureteral access sheath; OR was 1.49 (95% CI: 1.05-2.13) (Z = 2.22; p = 0.03). Risk of bias assessment showed 13 and 7 studies with low and moderate risk, respectively.

CONCLUSIONS

POS clearly improves the stone-free rates after fURS. It might reduce the complications, especially ureteral injury. These findings might help solve the current debate and can be useful for urologists during patient counselling for a proper decision-making.

Prestenting Versus Nonprestenting on the Outcomes of Flexible Ureteroscopy for Large Upper Urinary Stones: A Systematic Review and Meta-Analysis

INTRODUCTION

The purpose of this article is to evaluate the efficacy and safety of prestenting (PS) versus non-PS (NPS) of flexible ureteroscopy (fURS) to treat large upper urinary stones.

METHODS

We conducted a systematic literature research of PubMed, Ovid, Scopus (up to August 2019), and citation lists to identify eligible studies. All studies comparing PS versus NPS of fURS were included. Data were analyzed using the Cochrane Collaboration's Review Manager (RevMan) 5.3 software.

RESULTS

Overall, 7 studies including 3,145 patients (PS 1,408; NPS 1,737) were included in this article. PS group was associated with older age (weighted mean difference [WMD] 0.91 year; p < 0.001) and more male patients (odds ratio [OR] 1.34; p < 0.001). There were no statistical differences between PS and NPS in BMI (WMD 0.34 kg/m2; p = 0.13), stone size (WMD 0.13 mm; p = 0.77), and operative time (WMD 0.44 min; p = 0.86). Compared with NPS, PS showed better initial success rate (OR 4.04; p < 0.001) and higher SFR (OR 1.64; p < 0.001). There were no statistical differences for complications (OR 0.84; p = 0.42) and Clavien-Dindo score ≥3 complications (OR 1.04; p = 0.93).

CONCLUSION

PS could improve initial success rate and avoid secondary general anesthesia for first ureteral access sheath failed patients. PS could provide better SFR than NPS in the treatment of large upper urinary stones with fURS.

Risk Factors for Urosepsis After Ureteroscopy for Stone Disease: A Systematic Review with Meta-Analysis

Introduction: Urosepsis is a serious potential complication of ureteroscopic procedures for stone disease, yet the risk factors for this complication are not well characterized. The purpose of this systematic review with meta-analysis was to identify potential risk factors for urosepsis after ureteroscopy (URS) for stone disease. Materials and Methods: We performed systematic searches of Medline, Embase, and the Cochrane Central Register of Controlled Trials for studies reporting at least one prospectively defined risk factor for urosepsis after URS. Studies that only reported rates of isolated fever, urinary tract infection (UTI), or pooled infectious complications were excluded. The risk factors evaluated in this review were age, sex, body mass index, diabetes mellitus, ischemic heart disease, recent UTI, pyuria, hydronephrosis, stone history, stone size, preoperative stent placement, preoperative positive urine culture, and procedure time. A random effects meta-analysis model with inverse variance weighting was used where the statistic of interest was the odds ratio for dichotomous variables and the mean difference for continuous outcomes. Results: In 13 studies (5 prospective) with 5597 patients, the pooled incidence of postoperative urosepsis was 5.0% (95% confidence interval: 2.4-8.2). Six risk factors were statistically associated with increased postoperative urosepsis risk-preoperative stent placement (odds ratio = 3.94, p < 0.001, 6 studies), positive preoperative urine culture (odds ratio = 3.56, p < 0.001, 6 studies), ischemic heart disease (odds ratio = 2.49, p = 0.002, 2 studies), older age (mean difference = 2.7 years, p = 0.002, 6 studies), longer procedure time (mean difference = 9 minutes, p = 0.02, 1 study), and diabetes mellitus (odds ratio = 2.04, p = 0.04, 6 studies). Conclusions: Current evidence suggests that among patients undergoing URS for treatment of stone disease, the risk of postoperative urosepsis was 5.0%. Older age, diabetes mellitus, ischemic heart disease, preoperative stent placement, a positive urine culture, and longer procedure time were associated with increased postoperative urosepsis risk. These results will assist urologists with preoperative risk stratification before ureteroscopic procedures.

The feasibility of one-stage flexible ureteroscopy lithotripsy in solitary kidney patients with 1-3 cm renal stones and risk factors of renal function changes

Purpose

To compare perioperative outcomes and long-term renal function changes between prior stenting (PS) and not prior stenting (NPS) before flexible ureteroscopy lithotripsy (f-URS) for solitary kidney patients.

Methods

Solitary kidney patients with 10–30 mm renal stones were enrolled in this historical control study. Perioperative parameters and complications were compared. Stone-free was defined as the absence of any residual stones on a CT scan. Renal function changes were evaluated by estimated glomerular filtration rate (eGFR) and adjusted for body surface area. A decrease in the eGFR over 20% was identified as ‘deterioration’ in renal function. The follow-up period was at least 6 months. Logistic regression was used to identify risk factors of renal function deterioration.

Results

Of the 76 patients included, 40 cases experienced prior stenting before f-URS. The average stone diameter was 16.8 ± 4.7 mm, ranging from 10.0 to 28.4 mm. Initial SFR was 85.0 and 83.3% in the PS and NPS groups, respectively (p = 0.842), while SFR after the second procedure was 97.5 and 94.4% (p = 0.926). Seven PS and 5 NPS patients developed complications (p = 0.666). At the postoperative 6 months, seven patients showed a deteriorated renal function. Surgical time in minutes was identified as a risk factor for renal function deterioration after the operation (OR = 1.061, 95% CI: 1.015–1.109, p = 0.009, per minute).

Conclusion

It appears that one-stage f-URS without PS could be feasible for 10–30 mm renal stones in solitary kidney patients, and less surgical time might be beneficial to protect renal function.

Comparison of single-use and reusable flexible ureteroscope for renal stone management: a pooled analysis of 772 patients

Flexible ureteroscopy is a common therapy for patients with renal calculi. In recent years, the prevalence of single-use flexible ureteroscope (FURS) use has been on the rise. Thus, several trials have been conducted to compare the efficacy between single-use and reusable FURS. The aim of this meta-analysis was to systematically assess the effectiveness and safety of single-use vs. reusable FURS in treating renal stones. PubMed, Web of Science, Cochrane Library and EMBASE were researched to identify relevant studies up to September 2019. Article selection was performed through the search strategy based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The Newcastle-Ottawa Scale was applied to assess the methodological quality of non-randomized controlled trials, and the methodological quality of randomized controlled trials was evaluated using the Jadad scale. A total of five studies with 772 patients were included in the meta-analysis, including two randomized controlled trials, two single-centre prospective studies, and one prospective case-control trial. The pooled results showed that single-use FURS was associated with a higher stone-free rate (SFR) (OR: 1.50; 95% CI, 1.06–2.12; P=0.02) than reusable FURS. A significant difference was noted in operative time, and single-use FURS was associated with a longer operative duration (MD: 7.39 min; 95% CI, 1.75–13.03; P=0.01). No significant difference was noted in perioperative complications (OR: 0.97; 95% CI, 0.56–1.70; P=0.92). Subgroup analysis showed no significant difference in urinary tract infection (OR: 0.80; 95% CI, 0.44–1.46; P=0.46), stent migration (OR: 0.56; 95% CI, 0.19–1.65; P=0.30) or acute kidney injury (OR: 0.76; 95% CI, 0.16–3.57; P=0.73). Single-use FURS is an effective and safe alternative to reusable FURS for the management of renal stones.

Evaluation and comparison of scoring systems for predicting stone-free status after flexible ureteroscopy for renal and ureteral stones

OBJECTIVE

To evaluate four predictive scores for stone-free rate (SFR) after flexible ureterorenoscopy (f-URS) with holmium-YAG laser fragmentation of renal and ureteral lithiasis.

METHODS

We carried out a retrospective analysis of 800 f-URS procedures performed in our institution between January 2009 and December 2016. For each procedure, a single surgeon calculated the following scores: S.T.O.N.E score; Resorlu Unsal Stone Score (RUSS); modified Seoul National University Renal Complexity (S-ReSC) score; and Ito's score.

RESULTS

Overall SFR was 74.1%. Univariate analysis demonstrated that stone size (p<0.0001), stone volume (p<0.0001), stone number (p = 0.004), narrow lower pole infundibulopelvic angle (IPA) (p = 0.003) and lower pole location + IPA <45° (p = 0.011) were significantly associated with SFR. All scores differed between the stone-free and non-stone-free groups. Area under the curve of the receiving operator characteristics curve was calculated for each score: 0.617 [95%CI: 0.575-0.660] for the S.T.O.N.E score; 0.644 [95%CI: 0.609-0.680] for the RUSS; 0.651 [95%CI: 0.606-0.697] for the S-ReSC score; and 0.735 [95%CI: 0.692-0.777] for Ito's nomogram.

CONCLUSION

All four scores were predictive of SFR after f-URS. Ito's score was the most sensitive. However, the performance of all scores in this analysis was lower than in developmental studies.

Predictors of Urinary Infections and Urosepsis After Ureteroscopy for Stone Disease: a Systematic Review from EAU Section of Urolithiasis (EULIS)

PURPOSE OF REVIEW

To present the latest evidence related to the predictors of urinary tract infections (UTIs) and urosepsis after ureteroscopy (URS) for stone disease.

RECENT FINDINGS

Our review suggests that almost half of all post-URS complications are related to infectious complications although reported rates of urosepsis were low. The use of antibiotic prophylaxis, treatment of pre-operative UTI, and low procedural time seem to reduce this risk. However, the risk is higher in patients with higher Charlson comorbidity index, elderly patients, female gender, long duration of pre-procedural indwelling ureteric stents and patients with a neurogenic bladder and with high BMI. Infectious complications following ureteroscopy can be a source of morbidity and potential mortality. Although majority of these are minor, efforts must be taken to minimise them especially in high-risk patients. This includes the use of prophylactic antibiotics, limiting stent dwell and procedural time, prompt identification and treatment of UTI and urosepsis, and careful planning in patients with large stone burden and multiple comorbidities.

Prospects for the research and application of biodegradable ureteral stents: from bench to bedside

Ureteral stents are commonly used in urological practices but are frequently associated with patient discomfort, encrustation and stent-related infection. And a second procedure is needed to remove the stent. New biomaterials and designs have been attempted to solve these problems. The development of biodegradable ureteral stent shows promising prospects in future clinical applications. This article reviews the biomaterials and preparation methods commonly used in the present study of biodegradable ureteral stents. To date, none of the technological developments has lead to the 'ideal' biodegradable ureteral stent, but much progress has been made in the stent design by improving the physical characteristics and biocompatibility of the biomaterials. The controllability of degradation, the biggest problem faced currently, still needs to be further improved. In the future, the nanotechnology and chemical modification of biomaterials may be able to further optimize the properties of degradation.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

Clinical outcomes and costs of reusable and single-use flexible ureterorenoscopes: a prospective cohort study

The purpose of this study is to analyze clinical outcomes and costs of single-use flexible ureterorenoscopes in comparison with reusable flexible ureterorenoscopes in a tertiary referral center. Prospectively, 68 flexible ureterorenoscopies utilizing reusable (Flex-X2S, Flex-X^C, Karl Storz) and 68 applying single-use flexible ureterorenoscopes (LithoVue, Boston Scientific) were collected. Clinical outcome parameters such as overall success rate, complication rates according to Clavien-Dindo, operation time and radiation exposure time were measured. Cost analysis was based on purchase costs and recurrent costs for repair and reprocessing divided by number of procedures. In each group 68 procedures were available for evaluation. In 91% of reusable and 88% of single-use ureterorenoscopies stone disease was treated with a mean stone burden of 101 ± 226 and 90 ± 244 mm² and lower pole involvement in 47 and 41%, respectively (p > 0.05). Comparing clinical outcomes of reusable vs. single-use instruments revealed no significant difference for overall success rates (81 vs. 87%), stone-free rates (82 vs. 85%), operation time (76.2 ± 46.8 vs. 76.8 ± 40.2 min), radiation exposure time (3.83 ± 3.15 vs. 3.93 ± 4.43 min) and complication rates (7 vs. 17%) (p > 0.05). A wide range of repair and purchase costs resulted in total to $1212-$1743 per procedure for reusable ureterorenoscopy whereas price of single-use ureterorenoscopy was $1300-$3180 per procedure. The current work provided evidence for equal clinical effectiveness of reusable and single-use flexible ureterorenoscopes. Partially overlapping ranges of costs for single-use and reusable scopes stress the importance to precisely know the expenses and caseload when negotiating purchase prices, repair prices and warranty conditions.