The Impact of Stone Density on Operative Complications of Retrograde Intrarenal Surgery: A Multicenter Study with Propensity Score Matching Analysis

Is Psoas Muscle Mass Associated with Failure of Ureteral Access Sheath Insertion and Complications from Retrograde Intrarenal Surgery? A Case-Control Study from RIRSearch group

Objective: To investigate the association between psoas muscle mass (PMM) and failure of ureteral access sheath (UAS) insertion and complications from retrograde intrarenal surgery (RIRS). Materials and Methods: A multicenter retrospective case-control study was conducted that included patients who underwent RIRS despite failure of UAS insertion (Cohort 1) and confounder-matched control patients who underwent RIRS after successful UAS insertion (Cohort 2). For morphometric analysis of PMM, ipsilateral psoas muscle areas (iPMAs) were measured using the coreslicer.com webkit. After comparing demographic, clinical, and complication rates and iPMAs between cohorts, gender-specific median iPMAs were also determined to further subdivide patients in each cohort as either low iPMAs or high iPMAs. Thereafter, patients were also compared in terms of RIRS complications. Results: Cohort 1 included 86 patients whereas Cohort 2 consisted of 124 matched cases. The median (interquartile range) iPMAs were similar between the cohorts: Cohort 1, 11.05 (6.82-14.44) cm2 versus 11.12 (6.97-13.69) cm2 for Cohort 2 (P ˃ .05). There was a significant inverse relationship between iPMAs with age (r = -0.222) and Charlson comorbidity index (r = -0.180) for all patients (P ˂ .05). Perioperative and postoperative complication rates were 8.1% and 16.3% for Cohort 1 and 6.5% and 21% for Cohort 2, respectively. The complication rates were not statistically different between patients with high iPMAs and those with low iPMAs, in male or female patients (P > .05). Conclusions: These results show that failure of UAS was not associated with PMM. Furthermore, since the complication rates were similar between patients with high PMM and low PMM, RIRS may be a reliable treatment choice for sarcopenic patients as well as in nonsarcopenic patients.

Comparison of Thulium Fiber Laser versus Holmium laser in ureteroscopic lithotripsy: a Meta-analysis and systematic review

OBJECTIVES

To compare the efficacy and safety of thulium fiber laser (TFL) to holmium: YAG (Ho: YAG) laser in ureteroscopic lithotripsy for urolithiasis.

METHODS

PubMed, Web of Science, Embase, CENTRAL, SinoMed, CNKI database, VIP and Wanfang Database were systematically searched for all relevant clinical trials until September 2023. References were explored to identify the relevant articles. Meta-analysis was carried out for the retrieved studies using RevMan5.4.1 software, and the risk ratio, mean difference and 95% confidence interval were expressed. Statistical significance was set at p < 0.05. The main outcomes of this meta-analysis were stone-free rate (SFR), perioperative outcomes and intraoperative or postoperative complications.

RESULTS

Thirteen studies, including 1394 patients, were included. According to the results of pooled analysis, TFL was associated with significantly higher stone-free rate (SFR) [0.52, 95% CI (0.32, 0.85), P = 0.009], shorter operation time [-5.47, 95% CI (-8.86, -2.08), P = 0.002], and less stone migration [0.17, 95% CI (0.06, 0.50), P = 0.001]. However, there was no significant difference in terms of the laser time, duration of hospital stay, drop of hemoglobin level, total energy, postoperative ureteral stenting, the incidence of intraoperative complications or postoperative complications between TFL and Ho: YAGs.

CONCLUSION

The findings of this study demonstrated several advantages of TFL in terms of higher SFR, shorter operative time and less stone migration.

TRIAL REGISTRATION

The protocol of this systematic review was listed in PROSPERO ( www.crd.york.ac.uk/PROSPERO ) (Protocol number: CRD42022362550).

Do Hounsfield Units have any significance in predicting intra- and postoperative outcomes in retrograde intrarenal surgery using Holmium and Thulium fiber laser? Results from the FLEXible ureteroscopy Outcomes Registry (FLEXOR)

PURPOSE

To evaluate outcomes of flexible ureteroscopy for renal stones by comparing hard versus soft stones based on their attenuation on computed tomography (Hounsfield Units-HU).

METHODS

Patients were divided into two groups according to the type of laser employed [Holmium:YAG (HL) or Thulium fiber laser (TFL)]. Residual fragments (RF) were defined as > 2 mm. Multivariable logistic regression analysis was performed to evaluate factors associated with RF and RF needing further intervention.

RESULTS

4208 patients from 20 centers were included. In whole series, age, recurrent stones, stone size, lower pole stones (LPS), and multiple stones were predictors of RF at multivariable analysis and LPS and stone size with RF requiring further treatment. HU and TFL were associated with lesser RF and RF requiring an additional treatment. In HU < 1000 stones, recurrent stones, stone size, and LPS were predictors of RF at multivariable analysis, whereas TFL was less likely associated with RF. Recurrent stones, stone size, and multiple stones were predictors of RF requiring further treatment, while LPS and TFL were associated with lesser RF requiring further treatment. In HU ≥ 1000 stones, age, stone size, multiple stones, and LPS were predictors of RF at multivariable analysis, while TFL was less likely associated with RF. Stone size and LPS were predictors of RF requiring further treatment, whereas TFL was associated with RF requiring further treatment.

CONCLUSION

Stone size, LPS, and use of HL are predictors of RF after RIRS for intrarenal stones regardless of stone density. HU should be considered an important parameter in predicting SFR.