Environmental impact of single-use and reusable flexible cystoscopes.

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 CO2 /kg device for reusable flexible endoscopes and 8.54 kg CO2 /kg device for single-use endoscopes, the per-case manufacturing cost was 1.37 kg CO2 for single-use devices and 0.0017 kg CO2 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 CO2 , and per-case costs of device repackaging and repair were 0.005 and 0.02 kg CO2 , respectively. The total estimated per-case carbon footprint of single-use and reusable devices was 2.40 and 0.53 kg CO2 , 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.

Evolution of healthcare costs for lower urinary tract symptoms associated with benign prostatic hyperplasia.

PURPOSE: With the ubiquity of lower urinary tract symptoms due to benign prostatic hyperplasia (LUTS/BPH) in older men, costs related to this highly prevalent disease are likely significant but not well defined. With this study, we hoped to define costs related to LUTS/BPH care. METHODS: We utilized the Optum© de-identified Clinformatics® Data Mart Database (CDM) for privately insured male enrollees aged 40-64 years with LUTS/BPH (N ≈ 100,300 annually) and the Centers for Medicare and Medicaid Services Medicare 5% Sample for male beneficiaries aged 65 + years with LUTS/BPH (N ≈ 147,800 annually). Annual LUTS/BPH-related expenditures from 2004 to 2013 were age standardized and calculated overall and by age and service location. RESULTS: The Medicare cohort demonstrated a 23% increase in total costs over the study period with a 28% decrease in CDM costs. Decreases in inpatient hospital charges (45% for Medicare, 55% for CDM) were offset by increasing hospital-based outpatient fees (120% for Medicare, 87% for CDM). Overall, we estimated a total cost of at least $1.9 billion for treatment of men with LUTS/BPH for 2013. Per person expenditures increased with age within cohorts with an average per-person cost of $269 (CDM) and $248 (Medicare) in 2013. CONCLUSION: The distribution of healthcare expenditures for LUTS/BPH shifted across practice settings from 2004 to 2013, with increasing outpatient relative to inpatient expenditures. Total direct costs for LUTS/BPH in 2013 were at least $1.9 billion, not accounting for indirect costs or certain unmeasured populations.

A Global Survey of Ergonomics Practice Patterns and Rates of Musculoskeletal Pain Among Urologists Performing Retrograde Intrarenal Surgery.

Purpose: Retrograde intrarenal surgery (RIRS) requires urologists to adopt an awkward body posture for long durations. Few urologists receive training in ergonomics despite the availability of ergonomic best practices utilized by other surgical specialties. We characterize ergonomic practice patterns and rates of musculoskeletal (MSK) pain among urologists performing RIRS. Methods: A web-based survey was distributed through the Endourological Society, the European Association of Urology, and social media. Surgeon anthropometrics and ergonomic factors were compared with ergonomic best practices. Pain was assessed with the Nordic Musculoskeletal Questionnaire (NMQ). Results: Overall, 519 of 526 participants completed the survey (99% completion rate). Ninety-three percent of urologists consider ergonomic factors when performing RIRS to reduce fatigue (68%), increase performance (64%), improve efficiency (59%), and reduce pain (49%). Only 16% received training in ergonomics. Residents/fellows had significantly lower confidence in ergonomic techniques compared with attending surgeons with any career length. Adherence to proper ergonomic positioning for modifiable factors was highly variable. On the NMQ, 12-month rates of RIRS-associated pain in ≥1 body part, pain limiting activities of daily living (ADLs), and pain requiring medical evaluation were 81%, 51%, and 29%, respectively. Annual case volume >150 cases (odds ratio [OR] 0.55 [0.35-0.87]) and higher adherence to proper ergonomic techniques (OR 0.67 [0.46-0.97]) were independently associated with lower odds of pain. Limitations include a predominantly male cohort, which hindered the ability to assess gender disparities in pain and ergonomic preferences. Conclusions: Adherence to ergonomic best practices during RIRS is variable and may explain high rates of MSK pain among urologists. These results underscore the importance of utilizing proper ergonomic techniques and may serve as a framework for establishing ergonomic guidelines for RIRS.

Poor clinical guideline adherence and inappropriate testing for incident lower urinary tract symptoms associated with benign prostatic hyperplasia.

BACKGROUND: The American Urological Association makes recommendations for evaluation and testing for lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH) to help primary care providers and specialists identify LUTS/BPH and harmful related conditions including urinary retention and prostate or bladder cancer. Our understanding of provider adherence to these Guidelines is limited to single-site or nonrepresentative settings. METHODS: We analyzed two insurance claims databases: the Optum® de-identified Clinformatics® Data Mart database for privately insured males aged 40-64 years (N ≈ 1,650,900 annually) and the Medicare 5% Sample for males aged ≥65 years (N ≈ 546,000 annually). We calculated the annual prevalence of LUTS/BPH and comorbid bladder cancer and bladder stones from 2004 to 2013. We additionally examined LUTS/BPH incidence and adherence to testing guidelines in a cohort of men newly diagnosed with LUTS/BPH in 2009. RESULTS: While LUTS/BPH prevalence and incidence increased with increasing age, evaluation testing became less common. Urinalysis was the most common testing type but was performed in <60% of incident patients. Serum prostate-specific antigen (PSA) was the second most common test across age groups (range: 15-34%). Prevalence of comorbid bladder cancer (range: 0-4%), but not bladder stones (range: 1-2%), increased with increasing age. CONCLUSIONS: Although older men were at greater risk of LUTS/BPH than younger men, they were less likely to undergo testing at diagnosis. Recommended testing with urinalysis was poor despite higher prevalence of bladder cancer in older men and a standard recommendation for urinalysis since 1994. Providers should be more cognizant of AUA Guidelines when assessing LUTS/BPH patients.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Retrograde Intrarenal Surgery for the Management of Renal Stones.

BACKGROUND: Retrograde intrarenal surgery (RIRS) has become the preferred treatment modality for nephrolithiasis. However, because of ongoing uncertainties regarding the optimal perioperative management, operative technique, and postoperative follow-up, as well as a lack of standardization for outcome reporting, consensus is needed to achieve more uniform clinical practice worldwide. OBJECTIVE: To develop recommendations for RIRS on the basis of existing data and expert consensus. DESIGN, SETTING, AND PARTICIPANTS: A protocol-driven, three-phase study was conducted by the European Association of Urology Section of Urolithiasis (EULIS) and the International Alliance of Urolithiasis (IAU). The process included: (1) a nonsystematic review of the literature to define domains for discussion; (2) a two-round modified Delphi survey involving experts in this field; and (3) an additional group meeting and third-round survey involving 64 senior representative members to formulate the final conclusions. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The results from each previous round were returned to the participants for re-evaluation of their decisions during the next round. The agreement threshold was set at 70%. RESULTS AND LIMITATIONS: The panel included 209 participants who developed 29 consensus statements on the following topics of interest: (1) perioperative infection management; (2) perioperative antithrombotic therapy; (3) fundamentals of the operative technique; and (4) standardized outcome reporting. Although this consensus can be considered as a useful reference for more clinically oriented daily practice, we also acknowledge that a higher level of evidence from further clinical trials is needed. CONCLUSIONS: The consensus statements aim to guide and standardize clinical practice and research on RIRS and to recommend standardized outcome reporting. PATIENT SUMMARY: An international consensus on the best practice for minimally invasive surgery for kidney stones was organized and developed by two international societies. It is anticipated that this consensus will provide further guidance to urologists and may help to improve clinical outcomes for patients.

Contemporary considerations in the management and treatment of lower pole stones

ABSTRACT The presence of lower pole stones poses a unique challenge due to the anatomical considerations involved in their management and treatment. Considerable research has been performed to determine the optimal strategy when faced with this highly relevant clinical scenario. Standard options for management include observation, shock wave lithotripsy, retrograde intrarenal surgery, or percutaneous nephrolithotomy. Indeed, each approach confers a distinct set of risks and benefits, which must be placed into the context of patient preference and expected outcomes. The current state of practice reflects a combination of lessons learned from managing calculi not only in the lower pole, but also from other locations within the kidney as well.

Evidence-Based Recommendations for Opioid Prescribing After Endourological and Minimally Invasive Urological Surgery.

Introduction: Procedure-specific guidelines for postsurgical opioid use can decrease overprescribing and facilitate opioid stewardship. Initial recommendations were based on feasibility data from limited pilot studies. This study aims to refine opioid prescribing recommendations for endourological and minimally invasive urological procedures by integrating emerging clinical evidence with a panel consensus. Materials and Methods: A multistakeholder panel was convened with broad subspecialty expertise. Primary literature on opioid prescribing after 16 urological procedures was systematically assessed. Using a modified Delphi technique, the panel reviewed and revised procedure-specific recommendations and opioid stewardship strategies based on additional evidence. All recommendations were developed for opioid-naive adult patients after uncomplicated procedures. Results: Seven relevant studies on postsurgical opioid prescribing were identified: four studies on ureteroscopy, two studies on robotic prostatectomy including a combined study on robotic nephrectomy, and one study on transurethral prostate surgery. The panel affirmed prescribing ranges to allow tailoring quantities to anticipated need. The panel noted that zero opioid tablets would be potentially appropriate for all procedures. Following evidence review, the panel reduced the maximum recommended quantities for 11 of the 16 procedures; the other 5 procedures were unchanged. Opioids were no longer recommended following diagnostic endoscopy and transurethral resection procedures. Finally, data on prescribing decisions supported expanded stewardship strategies for first-time prescribing and ongoing quality improvement. Conclusion: Reductions in initial opioid prescribing recommendations are supported by evidence for most endourological and minimally invasive urological procedures. Shared decision-making before prescribing and periodic reevaluation of individual prescribing patterns are strongly recommended to strengthen opioid stewardship.

A micro-costing analysis of outpatient flexible cystoscopy: implications for adoption of single-use flexible cystoscopes.

PURPOSE: To evaluate the total cost of outpatient flexible cystoscopy associated with reusable device purchase, maintenance, and reprocessing, and to assess potential cost benefits of single-use flexible cystoscopes. METHODS: Cost data regarding the purchasing, maintaining, and reprocessing of reusable flexible cystoscopes were collected using a micro-costing approach at a high-volume outpatient urology clinic. We estimated the costs to facilities with a range of annual procedure volumes (1000-3000) performed with a fleet of cystoscopes ranging from 10 to 25. We also compared the total cost per double-J ureteral stent removal procedure performed using single-use flexible cystoscopes versus reusable devices. RESULTS: The cost associated with reusable flexible cystoscopes ranged from $105 to $224 per procedure depending on the annual procedure volume and cystoscopes available. As a practice became more efficient by increasing the ratio of procedures performed to cystoscopes in the fleet, the proportion of the total cost due to cystoscope reprocessing increased from 22 to 46%. For ureteral stent removal procedures, the total cost per procedure using reusable cystoscopes (range $165-$1469) was higher than that using single-use devices ($244-$420), unless the annual procedure volume was sufficiently high relative to the number of reusable cystoscopes in the fleet (≥ 350 for a practice with ten reusable cystoscopes, ≥ 700 for one with 20 devices). CONCLUSION: The cost of reprocessing reusable cystoscopes represents a large fraction of the total cost per procedure, especially for high-volume facilities. It may be economical to adopt single-use cystoscopes specifically for stent removal procedures, especially for lower-volume facilities.

Contemporary considerations in the management and treatment of lower pole stones.

The presence of lower pole stones poses a unique challenge due to the anatomical considerations involved in their management and treatment. Considerable research has been performed to determine the optimal strategy when faced with this highly relevant clinical scenario. Standard options for management include observation, shock wave lithotripsy, retrograde intrarenal surgery, or percutaneous nephrolithotomy. Indeed, each approach confers a distinct set of risks and benefits, which must be placed into the context of patient preference and expected outcomes. The current state of practice reflects a combination of lessons learned from managing calculi not only in the lower pole, but also from other locations within the kidney as well.

Surgical ergonomics for urologists: a practical guide.

Poor ergonomics in the operating room can have detrimental effects on a surgeon's physical, psychological and economic well-being. This problem is of particular importance to urologists who are trained in nearly all operative approaches (open, laparoscopic, robotic-assisted, microscopic and endoscopic surgery), each with their own ergonomic considerations. The vast majority of urologists have experienced work-related musculoskeletal pain or injury at some point in their career, which can result in leaves of absence, medical and/or surgical treatment, burnout, changes of specialty and even early retirement. Surgical ergonomics in urology has been understudied and underemphasized. In this Review, we characterize the burden of musculoskeletal injury in urologists and focus on various ergonomic considerations relevant to the urology surgeon. Although the strength of evidence remains limited in this space, we highlight several practical recommendations stratified by operative approach that can be incorporated into practice without interrupting workflow whilst minimizing injury to the surgeon. These recommendations might also serve as the foundation for ergonomics training curricula in residency and continuing medical education programmes. With improved awareness of ergonomic principles and the sequelae of injury related to urological surgery, urologists can be more mindful of their operating room environment and identify ways of reducing their own symptoms and risk of injury.

Evidence-based analysis of online consumer information about prostate artery embolization for benign prostatic hyperplasia.

BACKGROUND: Clinical guidelines have conflicting recommendations on the role of prostate artery embolization (PAE), a novel interventional radiology technique used to treat benign prostatic hyperplasia (BPH). In the absence of consensus among clinicians, patients may seek information online, where consumer-targeted content has proliferated in recent years. Our objective was to assess the content and quality of online information about prostate artery embolization (PAE). METHODS: We evaluated patient interest and exposure to PAE by searching Google Trends for PAE and searching Google for BPH and treatment-related terms. To assess online content about PAE safety and efficacy, we queried Google for patient-oriented websites and YouTube for consumer videos, assessing quality using the validated DISCERN instrument and performing an evidence-based content analysis of how indications, risks, and benefits of PAE were presented. RESULTS: Worldwide searches for PAE peaked in 2019; PAE was mentioned in 15 (26%) of the 57 general BPH-related websites. From our PAE-specific searches, we identified 50 websites and 31 videos. Academic hospitals were the most common sponsor of both PAE-related websites (16, 32%) and videos (15, 48%). Among sources offering PAE to patients, only 15% of websites and 11% of videos explicitly did so as part of a clinical trial. The average DISCERN rating of quality of content was 3.0 out of 5 for websites and 2.0 out of 5 for videos (p < 0.001). Over a quarter of websites and more than half of videos contained potential misinformation, inaccuracies, or non-evidence-based claims about PAE (p = 0.02). CONCLUSIONS: Online consumer information about PAE is of low to moderate quality, with a high frequency of non-evidence-based claims. In the absence of guideline consensus about the role of PAE, clinicians should offer shared decision making and evidence-based counseling about the risks and benefits of PAE.

Integrated Real-Time Digital Measurement During Ureteroscopic Procedures for Nephrolithiasis: A Workflow Feasibility Study.

Introduction: Accurate estimation of stone fragment size during ureteroscopic lithotripsy procedures facilitates operative efficiency and predicts the safety of fragment extraction or spontaneous passage. Using a novel stone measurement software application, this study assesses the feasibility of performing integrated real-time digital stone measurement during ureteroscopy. Methods: This workflow feasibility study was conducted in two phases. First, in the ex vivo simulation, mock stone fragments were placed in a renal collecting system training model. A basket extraction task was performed using a digital ureteroscope, with and without digital stone measurement. The time required to perform the tasks was recorded and compared. Second, in the in vivo workflow trial, adult patients undergoing ureteroscopic stone procedures were prospectively enrolled. Intraoperative measurements of stone fragments were performed to determine the time required to complete the measurements. Technical failures and perioperative complications were recorded. Results: In the ex vivo simulation, 20 mock stones mimicking varied fragmentation conditions were tested in the training model. The mean completion time of the basketing task without vs with digital stone measurement was 16.5 seconds (range 10.2-33.7) vs 38.9 seconds (range 27.2-60.0). Mean additional time required to measure stones was 22.3 seconds (range 8.4-42.7). In the in vivo workflow trial, nine patients undergoing ureteroscopy were enrolled. A median of five fragments (range 3-10) were measured in each patient. Mean completion time for each measurement was 10.1 seconds (range 8.2-12.8). Mean total time required to perform digital measurement per procedure was 50.8 seconds (range 25.9-99.0). No technical failures or clinical complications were observed. Conclusions: Integrating real-time digital stone measurement during ureteroscopy is safe and feasible. The findings support clinical trials of digital stone measurement to enhance intraoperative decision-making during ureteroscopy.

Recommendations for Opioid Prescribing after Endourological and Minimally Invasive Urological Surgery: An Expert Panel Consensus.

PURPOSE: Opioids are frequently overprescribed after surgery. The 2018 AUA position statement on opioid use suggests using the lowest dose and potency to achieve pain control but the lack of procedure specific prescribing guidelines contributes to wide variation in prescribing patterns. To address this gap we aimed to develop opioid prescribing recommendations through an expert panel consensus. MATERIALS AND METHODS: The 15-member multidisciplinary expert panel included representatives from 5 stakeholder groups. A 3-step modified Delphi method was used to develop recommendations for postoperative opioid prescribing. Recommendations were made for opioid naïve patients without chronic pain conditions. The panel used oxycodone 5 mg equivalents to define the number of prescribed tablets. RESULTS: Procedure specific recommendations were developed for 16 endourological and minimally invasive urological procedures. The panel agreed that not all patients desire or require opioids and, thus, the minimum recommended number of opioid tablets for all procedures was 0. Consensus ranges were identified to allow prescribed quantities to be aligned with expected needs. The maximum recommended quantity varied by procedure from 0 tablets (3 procedures) to 15 tablets (6 procedures) with a median of 10 tablets. Attending urologists typically voted for higher opioid quantities than nonattending panel members. The panel identified 8 overarching strategies for opioid stewardship, including contextualizing postoperative pain management with patient goals and preferences, and maximizing nonopioid therapies. CONCLUSIONS: Procedure specific guidelines for postoperative opioid prescribing may help align individual urologist prescribing habits with consensus recommendations. These guidelines can aid quality improvement efforts to reduce overprescribing in urology.

Trends in Lower Urinary Tract Symptoms Associated with Benign Prostatic Hyperplasia, 2004 to 2013: the Urologic Diseases in America Project.

PURPOSE: Our current understanding of recent trends in the management of lower urinary tract symptoms associated with benign prostatic hyperplasia is incomplete, particularly in younger men. The 2018 Urologic Diseases in America Project attempted to fill this gap by analyzing multiple large administrative claims databases which include men of all ages and permit longitudinal followup. To our knowledge we report these findings for the first time in the scientific literature. MATERIALS AND METHODS: The 2 data sources used in this study included the de-identified Optum® Clinformatics® Data Mart database for men 40 to 64 years old and the Medicare 5% Sample for men 65 years old or older. To assess trends in lower urinary tract symptoms/benign prostatic hyperplasia related medication prescriptions and surgical procedures from 2004 to 2013 we created annual cross-sectional cohorts and a longitudinal cohort of patients with incident lower urinary tract symptoms/benign prostatic hyperplasia and 5 years of followup. RESULTS: The use of medications related to lower urinary tract symptoms/benign prostatic hyperplasia increased with age, particularly among men 40 to 60 years old. While medication use increased with time, surgical procedures decreased. Increasing age correlated with a higher rate of surgical procedures in the longitudinal cohort. Younger men were more likely to elect treatments of lower urinary tract symptoms/benign prostatic hyperplasia which reportedly optimize sexual function. CONCLUSIONS: Medication use increased and surgery decreased during the study period. Treatment approaches to lower urinary tract symptoms/benign prostatic hyperplasia varied greatly by patient age. While the minority of men in the fifth and sixth decades of life required treatment, a sharp increase in treatment use was seen between these decades. Younger men were more likely to elect less invasive surgical options. Future studies of lower urinary tract symptoms/benign prostatic hyperplasia should focus on age specific treatment selection.

New Imaging Techniques in the Management of Stone Disease.

Recent advances in computed tomography, X-ray-based imaging, and ultrasonography have improved the accuracy of urinary stone detection and differentiation of stone composition while minimizing radiation exposure. Dual-energy computed tomography and digital tomosynthesis show promise in predicting mineral composition to optimize medical and surgical therapy. Electromagnetic tracking may enhance the use of ultrasonography to achieve percutaneous renal access for nephrolithotomy. This article reviews innovations in imaging technology in the contemporary management of urinary stone disease.

Trends in the Setting and Cost of Ambulatory Urological Surgery: An Analysis of 5 States in the Healthcare Cost and Utilization Project.

INTRODUCTION: With the rising costs of health care, surgical procedures have migrated from the inpatient to outpatient setting with more than 60% of urological procedures performed in the ambulatory setting. Ambulatory surgical centers have the potential to reduce costs but may also lead to overutilization. We assessed utilization of ambulatory surgical centers for urological procedures, case mix distribution compared to hospital based outpatient surgery departments and cost implications. METHODS: All outpatient urological procedures were identified from 5 states in the United States (2010 to 2014) using all payer data. Patient demographics, regional data, facility type (ambulatory surgical center vs hospital based outpatient surgery department) and total charges (converted to costs and inflation adjusted to 2014 USD) were determined. Analyses of overall number of procedures, population adjusted rates, annual percent change and adjusted linear regression models were performed. RESULTS: Of more than 37 million surgical procedures 1,842,630 (4.9%) were urological with overall annual percent change +0.97% (+1.09% hospital based outpatient surgery departments vs +0.41% ambulatory surgical centers) and 20.0% performed in ambulatory surgical centers. The proportion performed in ambulatory surgical centers decreased slightly with time (-0.48% per year, p <0.001). Overall costs totaled $4.78 billion, representing 7.6% of all ambulatory surgery (average cost per procedure $2,603.76). All procedures demonstrated reduced costs per case when performed in ambulatory surgical centers (range -$800 to -$1,800). Unadjusted net cost increase per procedure per year was +$147.79 (+$113.98 adjusted). Providers performing the top quartile (Q1) of procedures demonstrated reduced costs. CONCLUSIONS: Ambulatory urological surgery represents 5% of all surgical cases but 7.6% of costs. The rate of procedures is increasing steadily with performance in ambulatory surgical centers outpaced by those in hospital based outpatient surgery departments. The cost of ambulatory urological surgery is rising out of proportion to explanation by inflation, patient factors or case mix.

Individual renal unit urine sampling to identify unilateral metabolic defects
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AIMS: Preventing kidney stone recurrence relies on detecting and modifying urine chemistry abnormalities. The assumption is that an abnormality is due to a global metabolic defect present in both kidneys. However, we hypothesize that clinically significant unilateral defects may exist. We aimed to identify these patients by sampling urine from each renal unit. MATERIALS AND METHODS: Adults undergoing retrograde upper urinary tract surgery were eligible for inclusion. Excluded were patients with a solitary kidney, suspected urothelial malignancy, or urinary tract infection. Following informed consent, all patients proceeded to the operating room. After induction of anesthesia, cystoscopy with ureteral catheterization was performed with urine collected via gravity drainage for 10 minutes. Urine samples with adequate volume were analyzed for chemistry concentrations. A difference greater than the 75th percentile between matched pairs was considered significant. For urine pH, a difference of 0.5 was considered significant. RESULTS: A total of 47 patients were screened for eligibility with only 13 (28%) electing to enroll in the study (26 renal units). All subjects underwent successful bilateral ureteral catheterization with no adverse events observed or later reported. The mean (± SD) urine volume captured from the right and left renal units was 5.0 ± 7.4 cm3 and 6.6 ± 6.4 cm3, respectively. Urine was only captured from paired renal units in 8 participants (8/13; 62%). Of these 8 participants, 5 (5/8; 63%) had at least 1 unilateral metabolic defect. CONCLUSION: Unilateral renal unit urine sampling is safe and feasible. However, captured urine volumes are small and variable, but chemical analysis can still be performed. Unilateral defects in renal electrolyte handling are relatively common, but the clinical implications of these differences are still yet to be determined.
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Urine kidney injury markers do not increase following gastric bypass: a multi-center cross-sectional study.

INTRODUCTION: To determine if markers of kidney injury correlate with urinary oxalate excretion. If so, such biomarkers might be early predictors of oxalate nephropathy. Gastric bypass surgery for obesity is known to be associated with postoperative hyperoxaluria, which can lead to urolithiasis and kidney damage. MATERIALS AND METHODS: Patients were recruited from four large academic centers > 6 months following completion of gastric bypass surgery. Patients provided a spot urine sample for analysis of three markers of kidney injury: 8-iso-Prostaglandin F2 α, N-acetyl- ß -D-Glucosaminidase, and Neutrophil gelatinase-associated lipocalin. Patients also provided 24 hour urine samples for stone risk analysis. RESULTS: A total of 46 study patients provided samples, the average age was 48.4 +/- 11.3. There were 40 women and 6 men. There was no difference in the level of any of the three inflammatory markers between the study group and the reference range generated from healthy non-hyperoxaluric subjects. Neither oxalate excretion nor supersaturation of calcium oxalate correlated with any of the injury markers. There was no difference noted between those with hyperoxaluria (n = 17) and those with normoxaluria (n = 29) with respect to any of the injury markers. CONCLUSIONS: Though hyperoxaluria was common after bypass surgery, markers of kidney injury were not elevated after surgery. No correlation was found between urine oxalate excretion and any of the injury markers.

Ureteroscopic Laser Lithotripsy: A Review of Dusting vs Fragmentation with Extraction.

INTRODUCTION: Ureteroscopic laser lithotripsy is becoming the most commonly utilized treatment for patients with urinary calculi. The Holmium:YAG (yttrium aluminum garnet) laser is integral to the operation and is the preferred flexible intracorporeal lithotrite. In recent years, there has been increasing interest in examining the effect of varying the laser settings on the effectiveness of stone treatment. Herein, we review the two primary laser treatment approaches: dusting and fragmentation with extraction. METHODS: We reviewed PubMed and MEDLINE databases from January 1976 through January 2017. All authors participated in the development of consensus definitions of dusting and fragmentation with extraction. The review protocol adhered to preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology. RESULTS: When the Holmium:YAG laser is used to treat stones, there are two parameters that can be adjusted: power (J) and frequency (Hz). In one treatment paradigm, which became termed "fragmentation with extraction," laser settings that relied on high energy and low frequency were used. Another paradigm, which became termed "dusting," utilized low energy and high frequency settings, which had the effect of breaking off exceedingly small fragments from the stone. CONCLUSIONS: Both dusting and fragmentation with extraction approaches to ureteroscopic stone treatment are effective. In fact, there is little evidence that one approach is better than the other. However, each does have relative advantages and disadvantages, which should be considered. Although dusting tends to be associated with shorter procedure times and a lower risk of ureteral damage, this approach may place the patient at increased risk for future stone events should all of the resultant debris not be expelled from the collecting system. The active removal associated with fragmentation with extraction, in contrast, may provide for a more complete initial stone clearance.