Bilateral same-session flexible ureteroscopy for renal stones: a feasible method

Stone dust in endourology: a systematic review of its definition, management, and clinical impact

OBJECTIVE

To evaluate and synthesise the existing literature on stone dust (DUST) in endourology, focusing on its definition, creation methods, and removal techniques.

METHODS

A comprehensive electronic literature search was conducted using the PubMed/Medline, Web Of Science, and Embase databases to identify reports published until October 2024. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed to identify eligible studies. The outcomes assessed included the definition of DUST, the method by which DUST was created, and how it was removed, evaluating both in vitro and in vivo studies. The review also assessed the efficacy of different laser technologies, including holmium-yttrium-aluminium-garnet (Ho:YAG) laser, thulium fibre laser (TFL), and pulsed thulium-YAG laser (p-Tm:YAG) laser, in generating DUST and their clinical relevance in stone management.

RESULTS

The systematic review identified 43 eligible studies, revealing significant variability in the definition and evaluation of DUST. Criteria for DUST ranged from sub-millimetre particle sizes to functional properties like floatability and aspiration capability. While Ho:YAG lasers remain widely used for stone dusting, emerging technologies such as TFL and p-Tm:YAG lasers have shown superior efficiency in producing finer particles and reducing retropulsion. No consensus emerged regarding the settings used by surgeons and the pre-settings provided by laser manufacturers.

CONCLUSIONS

Despite the widespread use of dusting techniques in endourology, a standardised definition of DUST remains lacking, with significant variability in laser settings, particle sizes, and evacuation methods. It must be clarified whether DUST should be defined as a noun-representing a distinct entity with a precise definition-or as the result of the dusting process, in which case clear criteria are needed to characterise it accurately. Establishing standardised definitions and protocols through international consensus is crucial to optimising clinical outcomes and ensuring consistency in future research.

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.

Play it safe: renal function after bilateral flexible ureteroscopy for kidney stones

PURPOSE

We searched for perioperative renal function deterioration risk factors in patients that underwent bilateral flexible ureteroscopy (fURS) for kidney stones.

METHODS

From August 2016 to February 2020, symptomatic patients > 18 years old with bilateral kidney stones up to 20 mm in each side were prospectively studied. Serum creatinine samples were collected on admission to surgery, immediate postoperative (IPO), on POD 3, 10, and 30. Estimated glomerular filtration rate (eGFR) was calculated using Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) without a race coefficient.

RESULTS

Thirty patients underwent bilateral fURS. Comparing to preoperative eGFR, median IPO and POD3 eGFR (p < 0.001) were significantly lower, and POD10 (p = 0.092) and POD30 (p = 0.648) were similar to preoperative eGFR. During follow-up, 22/30 (73.3%), 14/30 (46.7%), and 7/30 (23.3%) of the patients presented a decrease > 10% eGFR, > 20% eGFR, and > 30% eGFR, respectively. Multivariate analysis demonstrated that lower preoperative eGFR is a risk factor for eGFR < 60 mL/min/1.73 m2, p = 0.019 [1.021-1.263; 1.136]; ASA > 1 is a risk factor for decrease of eGFR > 10%, p = 0.028 [1.25-51.13; 8.00]; longer operative time is a risk factor for decrease of eGFR > 20%, p = 0.042 [1.00-1.05; 1.028]; and operative time ≥ 120 min is a risk factor for decrease of eGFR > 30%, p = 0.026 [0.016-0.773; 0.113].

CONCLUSIONS

Renal function suffers a reversible decrease after bilateral fURS. Our study suggests that adequate selection of patients and maintaining operative time < 120 min are relevant factors in preventing acute renal function deterioration following bilateral fURS.

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.