Role of pre-operative ureteral stent on outcomes of retrograde intra-renal surgery (RIRS): systematic review and meta-analysis of 3831 patients and comparison of Asian and non-Asian cohorts

Impact of preoperative stenting in management of bilateral ureteral stones

OBJECTIVE

This study aims to evaluate the impact of preoperative stenting on surgical outcomes and complications in patients with bilateral ureteric stones, specifically assessing its role in reducing the need for subsequent interventions.

METHODS

A retrospective analysis was conducted at a tertiary center over eight years, involving 82 patients with bilateral ureteric stones. Patients were divided into two groups: Group 1 (no preoperative stenting) and Group 2 (preoperative stenting). Key data collected included demographics, preoperative stone sizes, preoperative serum creatinine levels, operative details, postoperative complications, and stone-free rates (SFR) at two weeks post-surgery. Statistical analyses were performed using SPSS 25.0.

RESULTS

Of the 54 patients analyzed (27 in each group), the mean age was 48.8 ± 12.7 for Group 1 and 52.3 ± 15.2 for Group 2. Group 2 exhibited significantly higher preoperative serum creatinine levels (p = 0.016). Secondary interventions were needed for 8 patients in Group 1 versus 3 in Group 2 (p = 0.042). The SFR was 67% in Group 1 and 78% in Group 2 (p = 0.361), indicating no statistically significant difference.

CONCLUSION

Preoperative stenting may enhance the success of surgical interventions for bilateral ureteric stones, potentially reducing the need for further procedures. Further prospective studies are needed to validate these findings and optimize management strategies.

The effect of preoperative ureteral stenting on the outcomes and complications of pediatric ureteroscopy: A systematic review and meta-analysis

INTRODUCTION

Small ureteral caliber may prohibit safe primary ureteroscopy (URS), particularly in children. Pre-stenting was proposed to passively dilate the ureter for later safer ureteral access. This meta-analysis aims to analyze outcomes of both primary and deferred ureteroscopy after a period of pre-stenting.

METHODS

PubMed, Scopus, Cochrane Library, and Web of Science were searched for studies comparing outcomes of primary and deferred ureteroscopy in children younger than 18 years with ureteral and/or renal stones. Outcomes of interest were stone free rate (SFR), complication rates, ureteral injury, urinary tract infection (UTI), operative time, stone migration, postoperative stenting use and ureteral access sheath use.

RESULTS

Four studies encompassing 826 patients were included. When attempted, primary ureteroscopic access was successful in 69-83 % of patients. SFR was higher in the pre-stenting group (OR 0.87, 95 % CI [0.81-0.94], P = 0.0005). No significant difference was found between the two groups in terms of the overall complications rate (RR 1.66, 95 % CI [0.93-2.96], P = 0.09), ureteral injury (RR 3.67, 95 % CI [0.43-31.66], P = 0.24) febrile UTI (RR 0.62 (95 % CI [0.15 to 2.5], P = 0.5), use of postoperative stent (OR 0.86, 95 % CI [0.52-1.44], P = 0.58), use of ureteral access sheath (RR 0.94 (95 % CI [0.73 to 1.22], P = 0.65), or stone migration (RR 2.28 (95 % CI [0.48 to 10.80], P = 0.30).

CONCLUSION

Although pre-stenting is associated with a relatively higher SFR, primary URS is successful in most pediatric patients without increased complication risk. We advocate primary URS whenever possible to allow stone treatment under a single anesthetic and minimize healthcare costs.

The utility of flexible and navigable suction access sheath (FANS) in patients undergoing same session flexible ureteroscopy for bilateral renal calculi: a global prospective multicenter analysis by EAU endourology

PURPOSE

To assess the 30-day stone-free rate and peri-operative outcomes of flexible ureteroscopy (FURS) with flexible and navigable suction ureteral access sheaths (FANS) in adults undergoing same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS).

METHODS

Prospectively data of 115 adult patients with bilateral kidney stone disease undergoing SSB-RIRS across 14 global centers between July 2023 and March 2024 were analyzed. Patient demographics, stone characteristics and operative outcomes were recorded. A low-dose non contrast CT scan was performed at 30 days to assess the stone-free rate and clinical outcomes.

RESULTS

Overall bilateral zero residual fragment(ZRF) was 42.6%; unilateral ZRF was 75.7%. Only two patients were noted to have residual fragments > 4 mm. 1.7% experienced Traxer-Thomas grade 1 ureteric injury which was managed with a ureteral stent for four weeks. No pelvicalyceal injury occured. Postoperative mean loin pain score was 1.7 ± 1.0. None had sepsis nor required blood transfusion. 4.3% required readmission within 30 days of surgery. Multivariate analysis indicated longer total operation time correlated with lower odds of achieving a 100% bilateral stone-free (ZRF) (OR 0.978, 95%CI = 0.959-0.994, p = 0.013).

CONCLUSION

To our knowledge, this is the first multicenter study demonstrating the use of FANS in SSB-RIRS can achieve bilateral ZRF with low complication and re-intervention rates. However, prolonged surgical time may negatively impact outcomes. The indications of bilateral renal stones management with FURS can be expanded in appropriate chosen patients.

Outcomes of Same-sitting bilateral Retrograde IntraRenal Surgery for renal stone in patients aged 70 years and above

OBJECTIVE

To evaluate outcomes of same sitting Bilateral Retrograde IntraRenal Surgery (SSB-RISRS) for kidney stone in patients aged ≥70 years.

METHODS

We retrospectively reviewed patients with bilateral kidney stones who underwent SSB-RISRS in 21 centers (January 2015-June 2022).

INCLUSION CRITERIA

patients aged ≥70 years, bilateral kidney stones diagnosed due to either unilateral or bilateral symptomatic presentation. Patients were divided into 2 groups. Group 1: patients aged 70-74 years, Group 2: patients aged ≥75 years.

RESULTS

There were 86 patients in Group 1 and 60 patients in Group 2. There was no difference between the groups for gender, ASA score, BMI, comorbidities, presenting symptoms, and positive preoperative urine culture. Group 2 had a significantly higher proportion of recurrent stone formers (54.7% vs 35.0%, p=0.03). A higher proportion of bilaterally pre-stented patients were present in group 2 (37.9% vs 18.6%). There was no difference in total operation time and rate of post-operative uni- and bilateral stent positioning. Surgery was discontinued in 15.1% and 18.3% of cases in groups 1 and 2, respectively (p=0.773). Median length of postoperative stay was 2 days in both groups. The most frequent complication was fever requiring antibiotics and prolonged admission (10.5% in group 1 and 11.7% in group 2, p>0.99). Sepsis rate was 2.3% patients in group 1 and none in group 2. 1.2% in group 1 required a blood transfusion due to hematuria. Bilateral SFR was similar (60.0% vs 47.7%, p=0.194).

CONCLUSIONS

SSB-RISRS in elderly patients demonstrated an acceptable safety profile with good bilateral SFR.

Assessing flexible ureteroscopy outcomes for lower Pole versus non lower Pole stones using the flexible and navigable suction ureteric access sheath: a prospective multicenter study by EAU Endourology and PEARLS group

PURPOSE

Use of suction in flexible ureteroscopy is increasing lately. The introduction of flexible and navigable suction access sheath (FANS) has shown improved stone free rate (SFR). However, its efficacy in lower pole stone (LPS) in terms of SFR and complications is yet to be studied.

METHODS

We collected data from 25 centers that included 394 adult patients undergoing ureteroscopy using FANS. Non contrast CT (NCCT) scan was done within first 30 days post operatively to access the SFR. Residual fragments were graded as A: 100% SFR; B: single fragment ≤ 2 mm; C: single fragment 2.1-4 mm; D: Single or multiple fragments > 4 mm. Post operative complications were recorded.

RESULTS

Out of 394 patients, non LPS (group1) comprised of 268 patients, rest 126 patients had LPS (group 2). Single stage zero fragment SFR was seen in 58.6% (group 1) vs. 54.8% (group 2) (P = 0.619). Single stage grade A + B SFR was achieved in 96.6% vs. 98.4% in groups 1 and 2 respectively. On multivariate analysis Thulium fiber laser use was significantly associated with higher odds of being grade A stone-free, while stone volume with lower odds. In LPS group only two patients needed reintervention. The highest grade of complication was Clavien 2, which was seen in 3.2% LPS group.

CONCLUSION

Use of flexible and navigable suction ureteric access sheath for lower pole stones is effective and safe. The stone free rate of lower pole stones is comparable to non-lower pole locations with very low reintervention rate in both groups.

Safety and effectiveness of preoperative stenting compared to non-stenting in ureteroscopy for urinary stone disease: a meta-analysis of comparative studies

PURPOSE

Ureteroscopy (URS) is considered one of the first-line surgical treatments for urinary stones < 2 cm. Preoperative stenting (PS) employment in URS for urolithiasis remains debated, with evidence differing in terms of outcomes and recommendations. We sought to evaluate the influence of PS on surgical outcomes compared to non-PS (NPS) in patients with renal and ureteral stones undergoing ureteroscopic lithotripsy.

METHODS

Databases were searched until December 2023 for randomized and non-randomized studies reporting perioperative outcomes for PS and NPS. Pooled data were analyzed through a Random-Effects model when Higgins I2% heterogeneity values were > 50%; otherwise, a Fixed-Effects model was employed. Results were reported as risk ratios (RR), or mean differences (MD) with 95% confidence intervals (CI). Statistical significance was set at p < 0.05.

RESULTS

The analysis included 23,668 patients from 25 included studies (5 non-randomized prospective and 20 retrospective studies). Higher stone-free rates (SFR) were observed in kidney and ureteral stones (RR 1.05; 95%CI 1.03-1.08; p ≤ 0.0001), especially if managed with flexible URS (RR 1.05; 95%CI 1.01-1.09) in the PS cohort. Additionally, lower rates of intraoperative (RR 0.70; 95%CI 0.49-0.99; p = 0.04) and postoperative complications (RR 0.82; 95%CI 0.70-0.95; p = 0.008) were seen with PS. Both groups had a comparable operative time, length of stay (LOS), ureteral access sheath (UAS) placement success, and SFR in semi-rigid URS.

CONCLUSION

Higher SFR with PS were seen in kidney and ureteral stones, especially if f-URS was employed. Moreover, perioperative complications did not increase with PS. Future randomized studies, evaluating cost-effectiveness and quality of life are needed.

Could radiological parameters help to predict the failure of ureteral access sheath placement

To identify the radiological parameters which may help to predict the success of ureteral access sheath (UAS) placement during retrograde intrarenal surgery (RIRS).The study included 49 patients in whom failure ureteral access sheath placement in RIRS and 49 control group patients who were successfully placement between January 2023 and December 2023. The age, gender, body mass index (BMI), non-contrast computed tomography (NCCT), and kidney ureter bladder (KUB) radiographs were compared between the two groups. Measurements of the anteroposterior (ap) diameter of the pelvic inlet, anteroposterior diameter of the pelvic outlet, interspinous distance diameter were taken from non-contrast computed tomography (NCCT), while pelvic anteroposterior diameter and pelvic lateral diameter were measured from kidney ureter bladder (KUB) radiography. There were no significant differences between the groups in age, gender, body mass index, ap pelvic inlet diameter, ap pelvic outlet, and interspinous distance diameter. However, a statistically significant difference was found between the pelvic ap diameter and pelvic lateral diameter values measured on the KUB radiography. The values for pelvic ap diameter and pelvic lateral diameter measured in the KUB radiographs can be used to predict the likelihood of UAS passage during RIRC procedures. However, further studies with larger patient groups are needed to establish a cut-off value.

Thulium fiber laser vs Ho:YAG in RIRS: a prospective randomized clinical trial assessing the efficacy of lasers and different fiber diameters (150 µm and 200 µm)

INTRODUCTION

The aims of the study: (1) to compare the Super Pulse Thulium Fiber Laser (SP TFL) and the holmium: yttrium-aluminium-garnet (Ho:YAG) lasers in retrograde intrarenal surgery (RIRS); (2) to compare the efficacy of SP TFL laser fibers of different diameters (150 μm and 200 μm).

METHODS

A prospective randomized single-blinded trial was conducted. Patients with stones from 10 to 20 mm were randomly assigned RIRS in three groups: (1) SP TFL (NTO IRE-Polus, Russia) with fiber diameter of 150 μm; (2) SP TFL with 200-μm fiber; and (3) Ho:YAG (Lumenis, USA) with 200-μm fiber.

RESULTS

Ninety-six patients with kidney stones were randomized to undergo RIRS with SP TFL using a 150-μm fiber (34 patients) and a 200-μm fiber (32 patients) and RIRS with Ho:YAG (30 patients). The median laser on time (LOT) in the 200-μm SP TFL group was 9.2 (6.2-14.6) min, in 150-μm SP TFL-11.4 (7.7-14.9) min (p = 0.390), in Ho:YAG-14.1 (10.8-18.1) min (p = 0.021). The total energy consumed in 200-μm SP TFL was 8.4 (5.8-15.2) kJ; 150-μm SP TFL - 10.8 (7.3-13.5) kJ (p = 0.626) and in Ho:YAG-15.2 (11.1-25.3) kJ (p = 0.005).

CONCLUSIONS

Irrespective of the density, RIRS with SP TFL laser has proven to be both a safe and effective procedure. Whilst the introduction of smaller fibers may have the potential to reduce the duration of surgery, SP TFL results in a reduction in the LOT and total energy for stone ablation in RIRS compared with Ho:YAG.

A comparative study of flexible ureteroscopic lithotripsy for upper urinary tract stones in patients with prior urosepsis following emergency drainage via retrograde ureteral stent or percutaneous nephrostomy

BACKGROUND

Patients with urosepsis associated with upper urinary tract stones require further stone management after emergency drainage.

OBJECTIVE

To evaluate the safety and efficacy of elective flexible ureteroscopic lithotripsy (F-URSL) for upper urinary tract stones in patients with prior urosepsis who have undergone emergency drainage using retrograde ureteral stent(RUS) or percutaneous nephrostomy (PCN).

METHOD

Between January 2017 and December 2021, clinical data were collected for 102 patients who underwent elective F-URSL following emergency drainage for urosepsis caused by upper ureteral or renal stones. The patients were categorized into two groups based on the drainage method used: the RUS group and the PCN group. The collected data included patient demographics, stone parameters, infection recovery after emergency drainage, and clinical outcomes post F-URSL. Subsequently, the data underwent statistical analysis.

RESULTS

A total of 102 patients were included in the statistical analysis, with 58 (56.86%) in the RUS group and 44 (43.14%) in the PCN group. Among the patients, 84 (82.35%) were female and 18 (17.65%) were male, with an average age of 59.36 years. Positive urine cultures were observed in 71 (69.61%) patients. Successful drainage was achieved in all patients in both groups, and there were no significant differences in the time required for normalization of white blood cell count (WBC) and body temperature following drainage. Additionally, all patients underwent F-URSL successfully, and no statistically significant differences were observed between the two groups in terms of operative time, stone-free rates, postoperative fever, and postoperative hospital stay.

CONCLUSION

Both RUS and PCN have been established as effective approaches for managing urosepsis caused by upper urinary tract stones. Furthermore, the impact of these two drainage methods on the subsequent management of stones through elective F-URSL has shown consistent outcomes.

Flexible ureteroscopy for lower pole calculus: is it still a challenge?

PURPOSE

Flexible ureteroscopy (fURS) is steadily gaining popularity in the management of renal calculi, including those located in the lower pole (LP). Due to difficulty in accessing to the LP of kidney in minority of cases with fURS and reports of lower stone-free rate (SFR), it is still considered as a challenge in selected cases. The purpose of the review was to analyze the various aspects of fURS for LP stones.

METHODS

An extensive review of the recent literature was done including different factors such as anatomy, preoperative stenting, stone size, flexible scopes, types of lasers, laser fibers, suction, relocation, stone-free rates, and complications.

RESULTS

The significance of various lower pole anatomical measurements remain a subject of debate and requires standardization. Recent improvements in fURS such as single-use digital scopes with better vision and flexibility, high power laser, thulium fiber laser, smaller laser fiber, and accessories have significantly contributed to make flexible ureteroscopy  more effective and safer in the management of LP stone. The utilization of thulium fiber lasers in conjunction with various suction devices is being recognized and can significantly improve SFR.

CONCLUSIONS

With the significant advancement of various aspects of fURS, this treatment modality has shown remarkable efficacy and gaining widespread acceptance in management of LP kidney stones. These developments have made the fURS of LP stones less challenging.

Influence of pre-stenting on RIRS outcomes. Inferences from patients of the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR)

BACKGROUND

Retrograde Intrarenal Surgery (RIRS) is recommended as an alternative to percutaneous nephrolithotomy for stones up to 2 cm. Pre-stenting before RIRS remains controversial with various studies differing in outcomes and recommendations. We aim to understand how pre-stenting influences surgical outcomes.

METHODS

A number of 6579 patients from the TOWER group registry were divided into pre-stented (group 1) and non-pre-stented groups (group 2). Patients aged ≥18 years old, with normal calyceal anatomy were enrolled. Patients with ureteric stones, anomalous kidneys, bilateral stones, planned for ECIRS were excluded.

RESULTS

Patients are homogeneously distributed in both groups (3112 vs. 3467). The predominant indication for pre-stenting was symptom relief. Overall stone size was comparable, whilst group 1 had a significantly more multiple (1419 vs. 1283, P<0.001) and lower-pole (LP) stones (1503 vs. 1411, P<0.001). The mean operative time for group 2 was significantly longer (68.17 vs. 58.92, P<0.001). Stone size, LP stones, age, recurrence and multiple stones are contributing factors for residual fragments at the multivariable analysis. The incidence of postoperative day 1 fever and sepsis was significantly higher in group 2, indicating that pre-stenting is associated with a lower risk of post-RIRS infection and a lower overall complications rate (13.62% vs. 15.89%) (P<0.001).

CONCLUSIONS

RIRS without pre-stenting can be considered safe without significant morbidity. Multiple, lower-pole and large stone is a significant contributor towards residual fragments. Patients who were not pre-stented had significantly higher but low-grade complications, especially for lower pole and large volume stones. While we do not advocate routine pre-stenting, a tailored approach for these patients should include proper counselling regarding pre-stenting.

A Feasibility Study on Clinical Utility, Efficacy and Limitations of 2 Types of Flexible and Navigable Suction Ureteral Access Sheaths in Retrograde Intrarenal Surgery for Renal Stones

OBJECTIVE

To evaluate stone-free rate, device maneuverability, and complications after retrograde intrarenal surgery (RIRS) using 2 different sizes of flexible and navigable suction ureteral access sheaths (FANS).

METHODS

A retrospective analysis was performed for patients who underwent RIRS for renal stones of any size, number, and location between November 2021 and October 2022. Group 1 had FANS of 12 French. Group 2 had FANS of 10 French. Both sheaths have a Y-shaped suction channel. Tip of 10 French FANS has 20% more flexibility. Lithotripsy was achieved using either thulium fiber or high-power holmium lasers. A 5-point Likert scale was used to assess the performance of each sheath.

RESULTS

There were 16 patients in Group 1 and 15 patients in Group 2. Baseline demographics and stone parameters were similar. Four patients in Group 2 had the same session bilateral RIRS. Sheath insertion was successful in all renal units but one. Ten French FANS had a higher percentage of excellent scores for ease of use, manipulation, and visibility. Neither of the sheaths had an average or difficult rating for all evaluation scales. A fornix rupture requiring prolonged stenting occurred in group 2. All patients were discharged within 24 hours of surgery. One patient in each group visited the emergency department (analgesic treatment). There were no infectious complications. At 3 months, a computed tomography scan showed that the absence of residual fragments >2 mm was significantly higher in Group 2 (94.7% vs 68.8%, P = 0.01).

CONCLUSION

The 10 Fr FANS showed a higher stone-free rate. There was no infectious complication using both sheaths.

Improving Outcomes of Same-sitting Bilateral Flexible Ureteroscopy for Renal Stones in Real-world Practice-Lessons Learnt from Global Multicenter Experience of 1250 Patients

Background

Bilateral kidney stones are commonly treated in staged procedures.

Objective

To evaluate outcomes after same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS) for renal stones.

Design setting and participants

Data from adults who underwent bilateral RIRS in 21 centers were retrospectively reviewed (from January 2015 to June 2022). The inclusion criteria were unilateral/bilateral symptomatic bilateral stone(s) of any size/location in both kidneys and bilateral stones on follow-up with symptom/stone progression. Stone-free rate (SFR) was defined as absence of any fragment >3 mm at 3 mo.

Outcome measurements and statistical analysis

Continuous variables are presented as medians and 25-75th percentiles. A multivariable logistic regression analysis was performed to evaluate independent predictors of sepsis and bilateral SFR.

Results and limitations

A total of 1250 patients were included. The median age was 48.0 (36-61) yr. Of the patients, 58.2% were prestented. The median stone diameter was 10 mm on both sides. Multiple stones were present in 45.3% and 47.9% of the left and right kidneys, respectively. Surgery was stopped in 6.8% of cases. The median surgical time was 75.0 (55-90) min. Complications were transient fever (10.7%), fever/infection needing prolonged stay (5.5%), sepsis (2%), and blood transfusion (1.3%). Bilateral and unilateral SFRs were 73.0% and 17.4%, respectively. Female (odds ratio [OR] 2.97, 95% confidence interval [CI] 1.18-7.49, p = 0.02), no antibiotic prophylaxis (OR 5.99, 95% CI 2.28-15.73, p < 0.001), kidney anomalies (OR 5.91, 95% CI 1.96-17.94, p < 0.001), surgical time ≥100 min (OR 2.86, 95% CI 1.12-7.31, p = 0.03) were factors associated with sepsis. Female (OR 1.88, 95% CI 1.35-2.62, p < 0.001), bilateral prestenting (OR 2.16, 95% CI 1.16-7.66, p = 0.04), and the use of high-power holmium:YAG laser (OR 1.63, 95% CI 1.14-2.34, p < 0.01) and thulium fiber laser (OR 2.50, 95% CI 1.32-4.74, p < 0.01) were predictors of bilateral SFR. Limitations were retrospective study and no cost analysis.

Conclusions

SSB-RIRS is an effective treatment with an acceptable complication rate in selected patients with kidney stones.

Patient summary

In this large multicenter study, we looked at outcomes after same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS) for renal stones in a large cohort. We found that SSB-RIRS was associated with acceptable morbidity and good stone clearance after a single session.

Impact of Preoperative Ureteral Stenting in Retrograde Intrarenal Surgery for Urolithiasis

Background and Objectives: Ureteral stent insertion passively dilates the ureter. Therefore, it is sometimes used preoperatively before flexible ureterorenoscopy to make the ureter more accessible and facilitate urolithiasis passage, especially when ureteroscopic access has failed or when the ureter is expected to be tight. However, it may cause stent-related discomfort and complications. This study aimed to assess the effect of ureteral stenting prior to retrograde intrarenal surgery (RIRS). Materials and Methods: Data from patients who underwent unilateral RIRS for renal stone with the use of a ureteral access sheath from January 2016 to May 2019 were retrospectively analyzed. Patient characteristics, including age, sex, BMI, presence of hydronephrosis, and treated side, were recorded. Stone characteristics in terms of maximal stone length, modified Seoul National University Renal Stone Complexity score, and stone composition were evaluated. Surgical outcomes, including operative time, complication rate, and stone-free rate, were compared between two groups divided by whether preoperative stenting was performed. Results: Of the 260 patients enrolled in this study, 106 patients had no preoperative stenting (stentless group), and 154 patients had stenting (stenting group). Patient characteristics except for the presence of hydronephrosis and stone composition were not statistically different between the two groups. In surgical outcomes, the stone-free rate was not statistically different between the two groups (p = 0.901); however, the operation time for the stenting group was longer than that of the stentless group (44.8 ± 24.2 vs. 36.1 ± 17.6 min; p = 0.001). There were no differences in the complication rate between the two groups (p = 0.523). Conclusions: Among surgical outcomes for RIRS with a ureteral access sheath, preoperative ureteral stenting does not provide a significant advantage over non-stenting with respect to the stone-free rate and complication rate.

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.

Preoperative patient optimization for endourological procedures: the current best clinical practice

PURPOSE OF REVIEW

Despite technological advancements in endourological surgery, there is room for improvement in preoperative patient optimization strategies. This review updates recent best clinical practices that can be implemented for optimal surgical outcomes.

RECENT FINDINGS

Outcome and complication predictions using novel scoring systems and techniques have shown to assist clinical decision-making and patient counseling. Innovative preoperative simulation and localization methods for percutaneous nephrolithotomy have been evaluated to minimize puncture-associated adverse events. Novel antibiotic prophylaxis strategies and further recognition of risk factors that attribute to postoperative infections have shown the potential to minimize perioperative morbidity. Accumulating data on the roles of preoperative stenting and selective oral alpha-blockers adds evidence to the current paradigm of preventive measures for ureteral injury.

SUMMARY

Ample tools and technologies exist that can be utilized preoperatively to improve surgical outcomes. The combination of these innovations, along with validation in larger-scale studies, presents the cornerstone of future urolithiasis management.

Role of Preoperative Ureteral Stent on Outcomes of Retrograde Intra-Renal Surgery (RIRS) in Children. Results From a Comparative, Large, Multicenter Series

OBJECTIVE

To assess outcomes of pre-stenting versus non-pre-stenting in children undergoing retrograde intrarenal surgery (RIRS) for intrarenal stones.

METHODS

Children/adolescent with kidney stones undergoing RIRS in 9 centers between 2015 and 2020 were retrospectively reviewed.

EXCLUSION CRITERIA

ureteral lithotripsy, bilateral procedures. Stone-free status was evaluated at 3-month and defined as a single residual fragment (RF) ≤2 mm/absence of multiple fragments. Patients were divided into two groups (Group 1 no-prestenting; Group 2 prestenting). Student's, Chi-square and Fisher's exact test was used to assess difference between groups. Univariable and multivariable logistic regression analysis were performed to predict RF. Statistical significance: P-value <0.05.

RESULTS

Three hundred eighty-nine children/adolescents were included (192 patients in Group 1). Prestented patients were younger compared with non-prestented (mean age 8.30 ± 4.93 vs 10.43 ± 4.30 years, P < 0.001). There were no differences in stone characteristics (number, size, locations). Lasing and total surgical time were similar. Urinary tract infections were more prevalent in Group 2 (10.7%) compared to Group 1 (3.7%, P = 0.016). Sepsis occurred in 2.1% of patients in Group 2 and no patient in Group 1 (P = 0.146). 30.7% patients in Group 1 and 26.4% in Group 2 had RF (P = 0.322). In univariate logistic regression analysis, stone size was associated with RF (OR 1.12 95%CI 1.06-1.18, P < 0.001), whereas Thulium fiber laser with a lower incidence (OR 0.24 95%CI 0.06-0.69, p=0.020). Multivariate logistic regression analysis showed that stone size was associated with RF (OR 1.20 95%CI 1.08-1.36, P = 0.001).

CONCLUSIONS

RIRS showed similar stone-free rate in pre and non-prestented children/adolescents, although prestented patients were younger. A higher risk of post-operative infections was reported in prestented patients.

Are adrenergic α1- antagonists beneficial for the access of retrograde ureteral access sheath or semi-rigid ureteroscope access? A systematic review and meta-analysis

Introduction

To evaluate the clinical benefit of preoperative adrenergic α1-antagonist therapy in the management of upper urinary calculi.

Materials and methods

Publications were searched for The Cochrane Central Register of Controlled Trials, EMBASE, and MEDLINE until 1 March 2022 that related to the adrenergic α1- antagonist intake as adjunctive therapy before retrograde surgery. Dichotomous data were reported with risk ratios (RR) with 95% confidence intervals (CIs) and the continuous data were reported with mean difference (MD) with 95% CIs.

Results

There were nine studies with 867 patients included in this meta-analysis. Preoperative adrenergic α1- antagonists could significantly elevate the compared with the placebo. Higher successful access rate to the stone was found in patients who received preoperative adrenergic α1- antagonists than those who received the placebo (RR 1.24; 95% CI 1.17-1.33). Besides, the application of preoperative adrenergic α1- antagonists can also elevate 4th-week stone-free rate (RR 1.20; 95% CI 1.12-1.28), decrease postoperative analgesia (RR 0.30;95% CI 0.20-0.46) and result in a lower risk of overall complications (RR 0.38; 95% CI 0.24-0.61).

Conclusion

Preoperative adjunctive adrenergic α1- antagonist therapy is effective and safe in the management of retrograde surgery with a higher successful access rate and lower risk of severe complications.

Ureteral Access Sheaths and Its Use in the Future: A Comprehensive Update Based on a Literature Review

Ureteral access sheaths (UASs) are part of urologist’s armamentarium when performing retrograde intrarenal surgery (RIRS). Recently, the world of RIRS has changed dramatically with the development of three game-changers: thulium fiber laser (TFL), smaller size single use digital flexible ureterosopes and intraoperative intrarenal pressure (IRP) measurement devices. We aimed to clarify the impact of UASs on IRP, complications and SFRs and put its indications in perspective of these three major technological improvements. A systematic review of the literature using the Medline, Scopus and Web of Science databases was performed by two authors and relevant studies were selected according to PRISMA guidelines. Recent studies showed that using a UAS lowers IRP and intrarenal temperature by increasing irrigation outflow during RIRS. Data on the impact of a UAS on SFRs, postoperative pain, risk of infectious complications, risk of ureteral strictures and risk of bladder recurrence of urothelial carcinoma after diagnostic RIRS were inconclusive. Prestenting for at least one week resulted in ureteral enlargement, while the influence of pre-operative administration of alpha-blockers was unclear. Since TFL, smaller single use digital ureteroscopes and devices with integrated pressure-measuring and aspiration technology seemed to increase SFRs and decrease pressure and temperature related complications, indications on the use of a UAS may decrease in the near future.

Identification of the Risk Factors for the Failure of Ureteral Access Sheath Placement

PURPOSE

Insertion of a ureteral access sheath (UAS) may fail in some patients in retrograde intrarenal surgery (RIRS), and this study aimed to seek preoperative risk factors for the failure of 12/14F UAS placement.

METHODS

We retrospectively analyzed 260 consecutive patients who underwent RIRS between May 2020 and March 2022 at our institution. Data on patient and stone characteristics and several computed tomography (CT)-based measurements were collected and compared between the success and failure UAS placement groups.

RESULTS

Twenty-nine (11.2%) patients failed to insert the UAS. Age, gender, height, weight, stone side, stone location, length of history, and computed tomography (CT)-based parameters were not significant differences between the two groups. Univariate logistic regression analyses showed sex (female/male) (odds ratio: 0.287 and 95% CI [0.107, 0.722], p=0.013), length of history 15-31 days (odds ratio: 0.315 and 95% CI [0.102, 0.974], p=0.045), length of history >31 days (odds ratio: 0.202 and 95% CI [0.051, 0.805], p=0.023), and diameter of the ipsilateral common iliac artery (odds ratio: 1.285 and 95% CI [1.018, 1.623], p=0.035) were associated with UAS placement.

CONCLUSION

Our study indicated that males, the short length of history, and the short diameter of the ipsilateral common iliac artery were the risk factors for the failure of UAS placement.

CT-Based Predictor for the Success of 12/14-Fr Ureteral Access Sheath Placement

PURPOSE

Ureteral access sheaths (UAS) are widely used in retrograde intrarenal surgery (RIRS), and this study aimed to develop a model for predicting the success of UAS placement based on computed tomography.

METHODS

We analyzed the clinical data of 847 patients who received ureteroscopy. Data on patient and stone characteristics and several computed tomography (CT)-based measurements were collected. A nomogram predicting the success of UAS placement was developed and validated using R software.

RESULTS

Two hundred and forty-seven patients were identified. Twenty-five patients (10.1%) failed to pass through the UAS. A model with three factors including the short diameter of ureteral calculi, the short diameter of hydronephrosis, and the diameter of the narrowest part of the renal parenchyma was to be strongly practical and had a high area under the curve on internal validation (80.3%). Using a threshold cutoff of 92%, the sensitivity and specificity for predicting UAS placement were 0.35 and 0.92, respectively.

CONCLUSION

Our study provides a nomogram for predicting the success of UAS placement, and this model could help discriminate patients who are likely to suffer from failed UAS insertion; preoperative ureteral stenting is recommended according to the prediction.