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Introduction: Infected ureteral stones are a urologic emergency and require urgent decompression. We set out to determine whether serum procalcitonin (PCT) could aid in the diagnosis of infected ureteral stones. Methods: All consecutive patients presenting to the emergency room from November 9, 2016, to November 10, 2018, with an obstructing ureteral stone were included. All patients had complete blood count, urinalysis (UA), PCT, and urine culture (UCx). Subgroup analysis was performed in a "clinically equivocal" cohort of afebrile patients defined as a leukocytosis >104/μL and UA with <50 white blood cells (WBCs) per high powered field (hpf). Patients with positive and negative UCx were compared. Results: A total of 231 patients were included, of whom 56 had a positive UCx. Of all covariates, UA WBCs with a cutoff of 9 per hpf performed best at predicting positive UCx with an area under the curve (AUC) of 0.87. PCT did not perform as well with an ideal cutoff of 0.08 ng/mL, having an AUC of 0.77, sensitivity 70.6%, specificity 73.9%, positive predictive value (PPV) 34.3%, and negative predictive value (NPV) 92.9%. When looking at the clinically equivocal cohort, UA WBCs with a cutoff of 6 per hpf appeared to perform best at predicting a positive UCx with an AUC of 0.72. PCT was less predictive in this cohort with an ideal cutoff of 0.3 ng/mL, having an AUC of 0.32, sensitivity 47.1%, specificity 85.2%, PPV 38.1%, and NPV 89.3%. Conclusion: PCT does not appear to be a superior marker for diagnosing urinary tract infection in the setting of obstructing ureterolithiasis when compared with components of the standard work-up. [ABSTRACT FROM AUTHOR]

Introduction: Reusable ureteroscope durability and need for repair are significant sources of expense and inefficiency for patients and urologists. Utilization of LithoVue™, a disposable flexible digital ureteroscope, may address some of these concerns. To identify its economic impact on clinical care, we performed a micro-cost comparison between flexible reusable fiberoptic ureteroscopes (URF-P6™) and LithoVue. Patients and Methods: For this prospective, single-center micro-costing study, all consecutive ureteroscopies performed during 1 week each in July and August 2016 utilized either URF-P6 or LithoVue ureteroscopes respectively. Workflow data were collected, including intraoperative events, postoperative reprocessing cycle timing, consumables usage, and ureteroscope cost data. Results: Intraoperative data analysis showed mean total operating room time for URF-P6 and LithoVue cases were 93.4 ± 32.3 and 73.6 ± 17.4 minutes, respectively (p = 0.093). Mean cost of operating room usage per case was calculated at $1618.72 ± 441.39 for URF-P6 and $1348.64 ± 237.40 for LithoVue based on institutional cost rates exclusive of disposables. Postoperative data analysis revealed costs of $107.27 for labor and consumables during reprocessing for URF-P6 cases. The costs of ureteroscope repair and capital acquisition for each URF-P6 case were $957.71 and $116.02, respectively. The total ureteroscope cost per case for URF-P6 and LithoVue were $2799.72 and $2852.29, respectively. Conclusions: Micro-cost analysis revealed that the cost of LithoVue acquisition is higher per case compared to reusable fiberoptic ureteroscopes, but savings are realized in labor, consumables, and repair. When accounting for these factors, the total cost per case utilizing these two ureteroscopes were comparable. [ABSTRACT FROM AUTHOR]

Introduction: Cystinuria is a genetic disorder marked by elevated urinary cystine excretion and recurrent cystine nephrolithiasis. Interestingly, despite seemingly similar contralateral renal anatomy, a subset of cystinuric patients consistently form stones in only one kidney. The aim of this study is to evaluate clinical outcomes in unilateral vs bilateral cystine stone formers. Patients and Methods: We performed a retrospective case--control study of cystinuric patients evaluated and treated at the University of California, San Francisco between 1994 and 2015 and categorized patients as either unilateral or bilateral stone formers. Clinical presentation, baseline patient demographics, stone procedures, medical therapy regimens, and long-term renal function were compared between the two groups. Results: A total of 42 cystine stone patients (22 female, 20 male) were included in the analysis. The median age at first presentation was 18.5 years and median age at study conclusion was 45.5 years. Two-thirds of patients (n = 28) had a history of bilateral stones, whereas one-third (n = 14) had unilateral stones. Medical therapy regimens were similar between groups. Despite an increased average number of lifetime surgeries (7.5 sessions for bilateral vs 3.7 sessions for unilateral, p < 0.05), there was no significant difference in medians of the most recent glomerular filtration rate when compared with unilateral stone formers (81.5 vs 95 mL/min, respectively; p = 0.28). Conclusions: The majority of cystinuric patients within our cohort form stones bilaterally during their lifetime, and require more surgical interventions than unilateral stone formers. Despite this, overall renal function is well preserved in unilateral and bilateral cystinuric stone formers treated with minimally invasive stone extraction procedures. [ABSTRACT FROM AUTHOR]

Purpose: Careful decontamination and sterilization of reusable flexible ureteroscopes used in ureterorenoscopy cases prevent the spread of infectious pathogens to patients and technicians. However, inefficient reprocessing and unavailability of ureteroscopes sent out for repair can contribute to expensive operating room (OR) delays. Time-driven activity-based costing (TDABC) was applied to describe the time and costs involved in reprocessing. Materials and Methods: Direct observation and timing were performed for all steps in reprocessing of reusable flexible ureteroscopes following operative procedures. Estimated times needed for each step by which damaged ureteroscopes identified during reprocessing are sent for repair were characterized through interviews with purchasing analyst staff. Process maps were created for reprocessing and repair detailing individual step times and their variances. Cost data for labor and disposables used were applied to calculate per minute and average step costs. Results: Ten ureteroscopes were followed through reprocessing. Process mapping for ureteroscope reprocessing averaged 229.0 ± 74.4 minutes, whereas sending a ureteroscope for repair required an estimated 143 minutes per repair. Most steps demonstrated low variance between timed observations. Ureteroscope drying was the longest and highest variance step at 126.5 ± 55.7 minutes and was highly dependent on manual air flushing through the ureteroscope working channel and ureteroscope positioning in the drying cabinet. Total costs for reprocessing totaled $96.13 per episode, including the cost of labor and disposable items. Conclusions: Utilizing TDABC delineates the full spectrum of costs associated with ureteroscope reprocessing and identifies areas for process improvement to drive value-based care. At our institution, ureteroscope drying was one clearly identified target area. Implementing training in ureteroscope drying technique could save up to 2 hours per reprocessing event, potentially preventing expensive OR delays. [ABSTRACT FROM AUTHOR]

Introduction: Endoscopic tools have provided versatile examination and treatment for kidney stone procedures. Despite endourologists researching urinary stone disease using endoscopes to collect tissue, this tissue collection method is limited. Endoscopically removed tissues are small in size, restricting the types of genomebased examination possible. We investigated a new method of renal papilla biopsy and RNA extraction to establish a genomic research methodology for kidney stone disease. Patients and Methods: We conducted a prospective multi-institutional study and collected renal papilla specimens from consecutive percutaneous nephrolithotomy and ureteroscopy (URS) cases performed for removal of upper urinary tract stones. Renal papilla tissue was extracted using ureteroscopic biopsy forceps after stone removal. RNA was extracted using two different extraction kits, and their quantity and quality were examined. Additionally, the impact of biopsy on surgical complications was compared between cases performed with and without biopsy by matched case–control analysis adjusted for age, gender, body mass index, bilaterality, and stone burden. Results: A total of 90 biopsies from 49 patients were performed, and the median duration between specimen collection and RNA extraction was 61 days. Both univariate and multivariate analyses showed BIGopsy® forceps usage significantly increased the total yield ( p = 0.004) and quality ( p = 0.001 for A260/280, p = 0.004 for A260/ A230) of extracted RNA. Extraction using the RNeasy Micro Kit® also improved A260/A230, whereas reduced RNA integrity number of extracted RNA by univariate and multivariate analyses ( p = 0.002 and p < 0.001, respectively). Moreover, matched case–control study demonstrated that endoscopic renal papilla biopsy caused no significant surgical complications, including bleeding, decreased stone clearance and hematocrit, and renal dysfunction. Biopsies during URS imparted an average of 20 minutes of procedure time over nonbiopsy cases. Conclusions: We demonstrate a safe methodology for optimal RNA extraction of renal papilla tissue. This technique will accelerate advanced genomic studies for kidney stone formers by facilitating larger tissue yields. [ABSTRACT FROM AUTHOR]

Objective: LithoVue™ is a novel, single-use, digital flexible ureteroscope that was released to the US market in January 2016. There are scant data regarding its performance in humans. Procedural outcomes comparing LithoVue with reusable ureteroscopes are presented in patients undergoing ureteroscopy for upper urinary tract pathology. Patients and Methods: Clinical outcomes between two groups of patients undergoing flexible ureteroscopy for upper urinary tract pathology were analyzed. The first group underwent surgery utilizing LithoVue, and the second group used reusable fiber-optic flexible ureteroscopes. Differences in procedural outcomes, operative times, and time spent in hospital were analyzed using two-tailed t-tests and chi-squared and Fisher's exact tests. Results: One hundred fifteen cases utilizing LithoVue and 65 cases utilizing reusable ureteroscopes were included in this study. Demographics, surgical indications, stone size, location, total stone burden, composition, procedural outcomes, and complications were comparable between groups. For all cases, LithoVue procedures lasted 54.1 ± 25.7 minutes compared with 64.5 ± 37.0 minutes for reusable scope procedures ( p < 0.05) and for stone removal cases, 57.3 ± 25.1 vs 70.3 ± 36.9 minutes, respectively ( p < 0.05). Scope failure occurred in 4.4% of LithoVue cases and 7.7% of reusable cases ( p = 0.27). Conclusions: LithoVue represents a feasible alternative to reusable ureteroscopes with a low rate of scope failure comparable with reusable ureteroscopes. Its use shortens procedure duration, a finding that warrants further investigation. [ABSTRACT FROM AUTHOR]