Nimmagadda, Naren

Objective To assess the effect of Moses™ 2.0 (Lumenis Be Ltd., Yokneam Illit, Israel; Boston Scientific, Marlborough, MA, USA) for lithotripsy of renal stones of 8–20 mm in diameter on operative time, surgeon workload, and retropulsion. Subjects/Patients and Methods In our multicentre, randomised, double‐blind clinical trial, patients were randomised 1:1 to standard or Moses 2.0 laser lithotripsy and stratified by stone size. Patients and surgeons were blinded to laser modality. Primary outcomes were total operative time as well as surgeon workload assessed by the National Aeronautics and Space Administration‐Task Load Index (NASA‐TLX). Secondary outcomes were stone retropulsion evaluated by blinded video review and postoperative clinical outcomes. Linear regression modelling was used for analysis. Results A total of 153 patients (79 Standard, 74 Moses 2.0) with similar clinical, stone, and operative characteristics were evaluated. There was no significant difference in operative times between the Standard and Moses 2.0 groups ( P = 0.73). Moses 2.0 was associated with lower effort, frustration, mental, physical, and temporal workload, as well as higher rated overall performance compared to the standard laser. Video review demonstrated no difference in rates of retropulsion ( P = 0.13). Complication rates (Standard: 13%; Moses 2.0: 10%) and stone‐free rates (Standard: 51%; Moses: 2.0 55%) were comparable. Conclusion Our study evaluated the impact of Moses 2.0 technology on high‐powered renal stone dusting, constituting the largest double‐blind trial of its kind to date. There was insufficient evidence to suggest any difference in operative times or clinical outcomes when using Moses 2.0 compared to standard laser lithotripsy. Moses 2.0 was associated with reduced surgeon workload, which has implicit impact on surgeon wellness.

Purpose: The ASPiration to Improve Renal Calculi Removal Effectiveness study showed steerable ureteroscopic renal evacuation (SURE) with CVAC that significantly reduced residual stone volume at 30 days vs standard ureteroscopy (URS). This report presents 2-year health care consumption and stone events (SE) and their link to residual stone volume and other variables ( n = 101 at primary end point; n = 93 at 2 years). Materials and Methods: Logistic regression identified predictors of health care consumption events (HCEs), that is, emergency department visits, hospitalization, surgical retreatment, and SE across the study population. Incidence was compared between the treatment groups with Kaplan–Meier survival analysis. Results: At 2 years, residual stone volume was significantly associated with both HCEs and SE. For every 100 mm 3 increase in residual stone volume, the HCE risk increased by 50% to 54%, and the SE risk increased by 70%. Stone-free rate, the number of residual fragments (RFs), and RF total stone burden (based on diameter) were not predictors. Significantly fewer HCEs occurred in the SURE group (3 vs 20 events, p = 0.0004). Survival analysis confirmed this (4.3% vs 20%, log-rank p = 0.02), with a 73% risk reduction (hazard ratio 0.27, 95% Cl 0.09–0.80, p = 0.02). Fewer SE occurred in the SURE group, although not statistically significant. These subjects also had longer event-free survival. Conclusion: High-quality volumetric analysis supports evaluation of stone removal therapies, as residual stone volume predicts HCEs and SE. SURE significantly reduces the downstream incidence and risk of HCEs compared with standard URS.

Purpose: We report the first multicenter, prospective, randomized noninferiority controlled trial of steerable ureteroscopic renal evacuation (SURE) for nephrolithiasis treatment. Materials and Methods: Candidates for laser lithotripsy ≥18 years with ≥1 renal stone ≥7 mm and 7–20 mm stone burden were randomized 1:1 SURE vs ureteroscopy (URS). SURE was performed using the CVAC Aspiration System, a novel steerable irrigation–aspiration catheter. The primary efficacy end point was noninferiority in stone-free rate (SFR) based on zero residual fragments (RFs) 30 days postprocedure on noncontrast computed tomography. Secondary end points were superiority tests, stone clearance (percent stone volume reduction), residual stone volume (RSV), SFR (no RF >2 mm), and SFR (no RF >4 mm) 30 days postprocedure. Results: Of the subjects, 123 were randomized and 101 qualified for efficacy analysis (SURE 46 vs URS 55). Despite randomization, baseline URS stone volume was higher (SURE 485.0 ± 432.5 mm 3 vs URS 713.3 ± 558.5 mm 3 ). The primary noninferiority end point was achieved (SURE SFR 48% vs URS SFR 49%, p = 0.027, −1.3% [90% confidence interval; −18%, 15%]). Stone clearance was significantly higher for SURE vs URS subjects (SURE 96.9 ± 5.6% vs URS 92.9 ± 11.6%, p = 0.036); RSV was significantly lower (SURE 14.3 ± 3 0.9 mm 3 vs URS 70.2 ± 144.9 mm 3 , p = 0.012). SURE stone clearance and RSV were independent of baseline stone volume, but for URS degraded with increasing baseline stone volume. Safety was comparable between groups. Conclusions: SFR for SURE subjects was noninferior compared with URS subjects; stone clearance and RSV were significantly better with SURE, independent of baseline stone volume.

Background: Residual fragments (RFs) after percutaneous nephrolithotomy (PCNL) have a significant impact on patients' quality of life and clinical course. There is a paucity of studies that evaluate the natural history of RFs after PCNL. The objective of this study is to compare rates of reintervention, complications, stone growth, and passage in patients with RFs >4, ≤4, and ≤2 mm after PCNL. Methods: Sites from the Endourologic Disease Group for Excellence (EDGE) research consortium examined data of PCNL patients from 2015 to 2019 with at least 1-year follow-up. RF passage, regrowth, reintervention, and complications were recorded and RFs were stratified into >4 and ≤4 mm groups, as well as >2 and ≤2 mm groups. Potential predictors for stone-related events after PCNL were determined using multivariable logistic regression analysis. It was hypothesized that larger RF thresholds would result in lower passage rates, faster regrowth, and greater clinically significant events (complications and reinterventions) than smaller RF thresholds. Results: A total of 439 patients with RFs >1 mm on CT postoperative day 1 were included in this study. For RFs >4 mm, rates of reintervention were found to be significantly higher and Kaplan–Meier curve analysis showed significantly higher rates of stone-related events. Passage and RF regrowth were not found to be significantly different compared with RFs ≤4 mm. However, RFs ≤2 mm had significantly higher rates of passage, and significantly lower rates of fragment regrowth (>1 mm), complications, and reintervention compared with RFs >2 mm. On multivariable analysis, older age, body mass index, and RF size were found to be predictive of stone-related events. Conclusions: With the largest cohort to date, this study by the EDGE research consortium further confirms that clinically insignificant residual fragment is problematic for patients after PCNL, particularly in older more obese patients with larger RFs. Our study underscores the importance of complete stone clearance post-PCNL and challenges the use of Clinically insignificant residual fragment (CIFR).