Matlaga, Brian R.

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.

Objectives To compare the carbon footprint and environmental impact of single‐use and reusable flexible cystoscopes. Materials and Methods We analysed the expected clinical lifecycle of single‐use (Ambu aScope™ 4 Cysto) and reusable (Olympus CYF‐V2) flexible cystoscopes, from manufacture to disposal. Performance data on cumulative procedures between repairs and before decommissioning were derived from a high‐volume multispecialty practice. We estimated carbon expenditures per‐case using published data on endoscope manufacturing, energy consumption during transportation and reprocessing, and solid waste disposal. Results A fleet of 16 reusable cystoscopes in service for up to 135 months averaged 207 cases between repairs and 3920 cases per lifecycle. Based on a manufacturing carbon footprint of 11.49 kg CO 2 /kg device for reusable flexible endoscopes and 8.54 kg CO 2 /kg device for single‐use endoscopes, the per‐case manufacturing cost was 1.37 kg CO 2 for single‐use devices and 0.0017 kg CO 2 for reusable devices. The solid mass of single‐use and reusable devices was 0.16 and 0.57 kg, respectively. For reusable devices, the energy consumption of reusable device reprocessing using an automated endoscope reprocessor was 0.20 kg CO 2 , and per‐case costs of device repackaging and repair were 0.005 and 0.02 kg CO 2 , respectively. The total estimated per‐case carbon footprint of single‐use and reusable devices was 2.40 and 0.53 kg CO 2 , respectively, favouring reusable devices. Conclusion In this lifecycle analysis, the environmental impact of reusable flexible cystoscopes is markedly less than single‐use cystoscopes. The primary contributor to the per‐case carbon cost of reusable devices is energy consumption of reprocessing.

Introduction: Patients who form kidney stones are typically advised to limit intake of nondairy animal protein. Plant-based meat products may be a processed substitute protein source for these patients and have recently gained popularity because of health concerns, increased retail availability, decreased environmental impact, and meat supply shortages during the COVID-19 pandemic. Despite these perceived benefits and tangential association with whole food plant-based diets, the potential lithogenic risks associated with these products are not well characterized. Methods: The U.S. Department of Agriculture database was queried with a sample of plant-based meat products widely available to U.S. consumers. Nutrient profile data were compiled and compared with animal protein data using standardized serving sizes. Primary protein sources were identified using verified ingredient lists. Oxalate content was extrapolated based on dietary data sources. Results: A total 47 plant-based meat products (16 beef, 11 pork, 10 chicken, and 10 seafood) were analyzed. Compared with their respective animal protein, most products contained on average fewer calories (plant-based beef 77%, pork 94%, chicken 86%, and seafood 83%) and less protein (plant-based beef 68%, pork 96%, chicken 53%, and seafood 54%). Most products used soy protein as the primary protein source (55%). Soy-based beef contained the highest average oxalate content (18 mg per serving), whereas soy-based seafood contained the lowest (7 mg). The most common non-soy protein source was pea protein (30%), containing trace amounts of oxalate. Sodium content was higher in most plant-based products overall (72%) and in each category (plant-based beef 109%, pork 128%, chicken 100%, and seafood 148%). Calcium content was higher (plant-based beef 317%, pork 144%, chicken 291%, and seafood 295%) compared with animal protein. Conclusions: Most plant-based meat products consist of protein sources that are, relative to animal protein sources, higher in oxalate, sodium, and calcium. Stone-forming patients should be counseled about the potential lithogenic risk of these processed products.