Prospective Multicenter Evaluation of Pain Before and After Removal of Nonobstructing Renal Calculi: A CoRE Initiative.

PURPOSE: Flank pain associated with stone disease is typically caused by a stone that obstructs urine flow. However, it is plausible that nonobstructing kidney stones may still cause pain. We performed a multicenter, observational trial to evaluate whether treatment of small nonobstructing calyceal stones improves pain and kidney stone-specific health-related quality of life. MATERIALS AND METHODS: Patients aged 18 years or older with nonobstructing renal stone(s) up to 10 mm in longest diameter and moderate to severe pain were recruited. All participants completed 3 questionnaires: the Brief Pain Inventory (BPI), the Patient-Reported Outcomes Measurement Information System pain interference form 6a, and the Wisconsin Stone Quality of Life questionnaire. Thereafter, all participants underwent ureteroscopy for renal stone treatment. All 3 questionnaires were repeated at 2, 6 to 8, and at 12 weeks postprocedure. The primary outcomes were change in preoperative to 12-week postoperative mean BPI score and worst BPI pain score. RESULTS: A total of 43 patients with nonobstructing kidney stones and associated flank pain were recruited. All stones were removed. Preoperatively, BPI scores for mean pain and worst pain were 5.5 and 7.2, respectively which decreased to 1.8 and 2.8 respectively at 12 weeks postoperatively. Wisconsin Stone Quality of Life questionnaire mean score increased from 70.4 to 115.3 at 12 weeks postoperatively. A total of 86% and 69% of patients had at least a 20% and 50% reduction in their mean pain scores, respectively. CONCLUSIONS: This study determined that patients benefit significantly from the removal of calyceal nonobstructing kidney stones for at least 12 weeks with a reduction in pain and an increase in quality of life. Therefore, surgical removal of these stones in this patient population should be offered as a treatment option.

Percutaneous nephrolithotomy versus retrograde intrarenal surgery for treatment of renal stones in adults.

BACKGROUND: Kidney stones (also called renal stones) can be a source of pain, obstruction, and infection. Depending on size, location, composition, and other patient factors, the treatment of kidney stones can involve observation, shock wave lithotripsy, retrograde intrarenal surgery (RIRS; i.e. ureteroscopic approaches), percutaneous nephrolithotomy (PCNL), or a combination of these approaches. OBJECTIVES: To assess the effects of percutaneous nephrolithotomy (PCNL) versus retrograde intrarenal surgery (RIRS) for the treatment of renal stones in adults. SEARCH METHODS: We performed a comprehensive search of the Cochrane Library, MEDLINE, Embase, Scopus, and two trials registries up to 23 March 2023. We applied no restrictions on publication language or status. SELECTION CRITERIA: We included randomized controlled trials that evaluated PCNL (grouped by access size in French gauge [Fr] into three groups: ≥ 24 Fr [standard PCNL], 15-23 Fr [mini-PCNL and minimally invasive PCNL], and < 15 Fr [ultra-mini-, mini-micro-, super-mini-, and micro-PCNL]) versus RIRS. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies and extracted data from the included studies. Our primary outcomes were stone-free rate, major complications, and need for secondary interventions. Our main secondary outcomes were unplanned medical visits to emergency/urgent care or outpatient clinic, length of hospital stay, ureteral stricture or injury, and quality of life. We performed statistical analyses using a random-effects model. We rated the certainty of evidence using GRADE criteria. We adopted a minimally contextualized approach with predefined thresholds for minimal clinically important differences (MCIDs). MAIN RESULTS: We included 42 trials assessing the effects of PCNL versus RIRS in 4571 randomized participants. Twenty-two studies were published as full-text articles, and 20 were published as abstract proceedings. The average size of stones ranged from 10.1 mm to 39.1 mm. Most studies did not report sources of funding or conflicts of interest. The main results for the most important outcomes are summarized below. Stone-free rate PCNL compared with RIRS may improve stone-free rates (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.08 to 1.18; I2 = 71%; 39 studies, 4088 participants; low-certainty evidence). Based on 770 participants per 1000 being stone-free with RIRS, this corresponds to 100 more (62 more to 139 more) stone-free participants per 1000 with PCNL (an absolute difference of 10%, where the predefined MCID was 5%). Major complications PCNL compared with RIRS probably has little or no effect on major complications (RR 0.86, 95% CI 0.59 to 1.25; I2 = 15%; 34 studies, 3649 participants; moderate-certainty evidence). Based on 31 complications in the RIRS group, this corresponds to six fewer (13 fewer to six more) major complications per 1000 with PCNL (an absolute difference of 0.6%, where the predefined MCID was 2%). Need for secondary interventions PCNL compared with RIRS may reduce the need for secondary interventions (RR 0.31, 95% CI 0.17 to 0.55; I2 = 61%; 21 studies, 2005 participants; low-certainty evidence). Based on 222 secondary interventions in the RIRS group, this corresponds to 153 fewer (185 fewer to 100 fewer) secondary interventions per 1000 with PCNL (an absolute difference of 15.3%, where the predefined MCID was 5%). Unplanned medical visits No studies reported unplanned medical visits. Length of hospital stay PCNL compared with RIRS may extend length of hospital stay (mean difference 1.04 days more, 95% CI 0.27 more to 1.81 more; I2 = 100%; 26 studies, 2804 participants; low-certainty evidence). This effect size is greater than the predefined MCID of one day. Ureteral stricture or injury PCNL compared with RIRS may have little or no effect on the occurrence of ureteral strictures (RR 0.93, 95% CI 0.39 to 2.21; I2 = 0%; 13 studies, 1574 participants; low-certainty evidence). Based on 14 ureteral strictures in the RIRS group, this corresponds to one fewer (nine fewer to 17 more) ureteral strictures per 1000 with PCNL (an absolute difference of 0.1%, where the predefined MCID was 2%). Quality of life No studies reported quality of life. AUTHORS' CONCLUSIONS: Based on a large body of evidence from 42 trials, we found that PCNL compared with RIRS may improve stone-free rates and may reduce the need for secondary interventions, but probably has little or no effect on major complications. PCNL compared with RIRS may have little or no effect on ureteral stricture rates and may increase length of hospital stay. We found no evidence on unplanned medical visits or participant quality of life. Because of the considerable shortcomings of the included trials, the evidence for most outcomes was of low certainty. Access size for PCNL was less than 24 Fr in most studies that provided this information. We expect the findings of this review to be helpful for shared decision-making about management choices for individuals with renal stones.

Tranexamic acid for percutaneous nephrolithotomy.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) is the gold standard for the treatment of large kidney stones but comes with an increased risk of bleeding compared to other treatments, such as ureteroscopy and shock wave lithotripsy. Tranexamic acid (TXA) is an antifibrinolytic agent that has been used to reduce bleeding complications in other settings. OBJECTIVES: To assess the effects of TXA in individuals with kidney stones undergoing PCNL. SEARCH METHODS: We performed a comprehensive literature search of the Cochrane Library, PubMed (including MEDLINE), Embase, Scopus, Global Index Medicus, trials registries, other sources of the grey literature, and conference proceedings. We applied no restrictions on the language of publication nor publication status. The latest search date was 11 May 2023. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that compared treatment with PCNL with administration of TXA to placebo (or no TXA) for patients ≥ 18 years old. DATA COLLECTION AND ANALYSIS: Two review authors independently classified studies and abstracted data. Primary outcomes were: blood transfusion, stone-free rate (SFR), and thromboembolic events (TEEs). Secondary outcomes were: adverse events (AEs), secondary interventions, major surgical complications, minor surgical complications, unplanned hospitalizations or readmissions, and hospital length of stay (LOS). We performed statistical analyzes using a random-effects model. We rated the certainty of evidence (CoE) according to the GRADE approach using a minimally contextualized approach with predefined thresholds for minimally clinically important differences (MCIDs). MAIN RESULTS: We analyzed 10 RCTs assessing the effect of systemic TXA in PCNL versus placebo (or no TXA) with 1883 randomized participants. Eight studies were published as full text. One was published in abstract proceedings, but it was separated into two separate studies for the purpose of our analyzes. Average stone surface area ranged 3.45 to 6.62 cm2. We also found a single RCT published in full text assessing the effects of topical TXA in PCNL versus placebo (or no TXA) with 400 randomized participants, the results of which are further described in the review. Here we focus only on the results of TXA used systemically. Blood transfusion - Based on a representative baseline risk of 5.7% for blood transfusions taken from a large presentative observational studies, systemic TXA may reduce blood transfusions (risk ratio (RR) 0.45, 95% confidence interval (CI) 0.27 to 0.76; I2 = 28%; 9 studies, 1353 participants; low CoE). We assumed an MCID of ≥ 2%. Based on 57 participants per 1000 with placebo (or no TXA) being transfused, this corresponds to 31 fewer (from 42 fewer to 14 fewer) participants being transfused per 1000. Stone-free rate - Based on a representative baseline risk of 75.7% for SFR, systemic TXA may increase SFRs (RR 1.11, 95% CI 0.98 to 1.27; I2 = 62%; 4 studies, 603 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 757 participants per 1000 being stone free with placebo (or no TXA), this corresponds to 83 more (from 15 fewer to 204 more) stone-free participants per 1000. Thromboembolic events - There is probably no difference in TEEs (risk difference (RD) 0.00, 95% CI -0.01 to 0.01; I2 = 0%; 6 studies, 841 participants; moderate CoE). We assumed an MCID of ≥ 2%. Since there were no thromboembolic events in intervention and/or control groups in 5 out of6 studies, we opted to assess a risk difference with systemic TXA for this outcome. Adverse events - Systemic TXA may increase AEs (RR 5.22, 95% CI 0.52 to 52.72; I2 = 75%; 4 studies, 602 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 23 participants per 1000 with placebo (or no TXA) having an adverse event, this corresponds to 98 more (from 11 fewer to 1000 more) participants with adverse events per 1000. Secondary interventions - Systemic TXA may have little to no effect on secondary interventions (RR 1.15, 95% CI 0.84 to 1.57; I2 = 0%; 2 studies, 319 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 278 participants per 1000 with placebo (or no TXA) having a secondary intervention, this corresponds to 42 more (from 44 fewer to 158 more) participants with secondary interventions per 1000. Major surgical complications - Based on a representative baseline risk for major surgical complications of 4.1%, systemic TXA may reduce major surgical complications (RR 0.36, 95% CI 0.21 to 0.62; I2 = 0%; 5 studies, 733 participants; moderate CoE). We assumed an MCID of ≥ 2%. Based on 41 participants per 1000 with placebo (or no TXA) having a major surgical complication, this corresponds to 26 fewer (from 32 fewer to 16 fewer) participants with major surgical complications per 1000. Minor surgical complications - Systemic TXA may reduce minor surgical complications (RR 0.71, 95% CI 0.45 to 1.10; I2 = 76%; 5 studies, 733 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 396 participants per 1000 with placebo (or no TXA) having a minor surgical complication, this corresponds to 115 fewer (from 218 fewer to 40 more) participants with minor surgical complications per 1000. Unplanned hospitalizations or readmissions - We are very uncertain how unplanned hospitalizations or readmissions are affected (RR 1.55, 95% CI 0.45 to 5.31; I2 = not applicable; 1 study, 189 participants; very low CoE). We assumed an MCID of ≥ 2%. Hospital length of stay - Systemic TXA may reduce hospital LOS (mean difference 0.52 days lower, 95% CI 0.93 lower to 0.11 lower; I2 = 98%; 7 studies, 1151 participants; low CoE). We assumed an MCID of ≥ 0.5 days. AUTHORS' CONCLUSIONS: Based on 10 RCTs with substantial methodological limitations that lowered all CoE of effect, we found that systemic TXA in PCNL may reduce blood transfusions, major and minor surgical complications, and hospital LOS, as well as improve SFRs; however, it may increase AEs. We are uncertain about the effects of systemic TXA on other outcomes. Findings of this review should assist urologists and their patients in making informed decisions about the use of TXA in the setting of PCNL.

Development of a burst wave lithotripsy system for noninvasive fragmentation of ureteroliths in pet cats.

BACKGROUND: Upper urinary tract stones are increasingly prevalent in pet cats and are difficult to manage. Surgical procedures to address obstructing ureteroliths have short- and long-term complications, and medical therapies (e.g., fluid diuresis and smooth muscle relaxants) are infrequently effective. Burst wave lithotripsy is a non-invasive, ultrasound-guided, handheld focused ultrasound technology to disintegrate urinary stones, which is now undergoing human clinical trials in awake unanesthetized subjects. RESULTS: In this study, we designed and performed in vitro testing of a modified burst wave lithotripsy system to noninvasively fragment stones in cats. The design accounted for differences in anatomic scale, acoustic window, skin-to-stone depth, and stone size. Prototypes were fabricated and tested in a benchtop model using 35 natural calcium oxalate monohydrate stones from cats. In an initial experiment, burst wave lithotripsy was performed using peak ultrasound pressures of 7.3 (n = 10), 8.0 (n = 5), or 8.9 MPa (n = 10) for up to 30 min. Fourteen of 25 stones fragmented to < 1 mm within the 30 min. In a second experiment, burst wave lithotripsy was performed using a second transducer and peak ultrasound pressure of 8.0 MPa (n = 10) for up to 50 min. In the second experiment, 9 of 10 stones fragmented to < 1 mm within the 50 min. Across both experiments, an average of 73-97% of stone mass could be reduced to fragments < 1 mm. A third experiment found negligible injury with in vivo exposure of kidneys and ureters in a porcine animal model. CONCLUSIONS: These data support further evaluation of burst wave lithotripsy as a noninvasive intervention for obstructing ureteroliths in cats.

Predicting Septic Shock After Emergent Ureteral Stenting in Stone-Related Obstruction and Presumed Infections.

Introduction: Systemic inflammatory response syndrome (SIRS) criteria have long been used to predict septic shock. The sequential organ failure assessment and quick sequential organ failure assessment (qSOFA) scores have been suggested to be more accurate predictors. This study aims to compare SIRS and qSOFA for predicting of septic shock in the setting of retrograde ureteral stenting for obstructing stones and concomitant urinary tract infection. Methods: A retrospective review of records at two centers of consecutive patients was performed. Patients with unilateral ureteral obstruction by a stone who underwent ureteral stent placement and suspicion of urinary tract infection were identified. Primary endpoints were SIRS and qSOFA positive scores, intensive care unit admission, and vasopressor requirements. Results: A total of 187 patients were included. SIRS criteria were met in 103 patients (55.1%) and in 30 patients who experienced septic shock. qSOFA criteria were met for 24 patients (12.8%) and in 18 patients who experienced septic shock. Specificity for postoperative septic shock was significantly higher for qSOFA than for SIRS criteria (75 vs 29.1%, McNemar test p < 0.001). Both SIRS and qSOFA had significant areas under the curve (AUC), qSOFA had a fair AUC of 0.750, p = 0.001, whereas SIRS had a poor AUC of 0.659, p = 0.008. Univariate logistic regression of SIRS and qSOFA for septic shock showed: qSOFA (odds ratio [OR] 46 [0.25-228], p = 0.001) and SIRS (OR 2.29 [0.716-7.37], p = 0.162). Conclusion: Although SIRS offers higher sensitivity, qSOFA score may offer advantages over SIRS criteria in evaluation of risk for septic shock for patients who present with obstructing ureteral stone and urinary tract infection.

Heterogeneity in stone culture protocols and endourologist practice patterns: a multi-institutional survey.

Kidney stone cultures can be beneficial in identifying bacteria not detected in urine, yet how stone cultures are performed among endourologists, under what conditions, and by what laboratory methods remain largely unknown. Stone cultures are not addressed by current clinical guidelines. A comprehensive REDCap electronic survey sought responses from directed (n = 20) and listserv elicited (n = 108) endourologists specializing in kidney stone disease. Questions included which clinical scenarios prompt a stone culture order, how results influence post-operative antibiotics, and what microbiology lab protocols exist at each institution with respect to processing and resulting stone cultures. Logistic regression statistical analysis determined what factors were associated with performing stone cultures. Of 128 unique responses, 11% identified as female and the mean years of practicing was 16 (range 1-46). A specific 'stone culture' order was available to only 50% (64/128) of those surveyed, while 32% (41/128) reported culturing stone by placing a urine culture order. The duration of antibiotics given for a positive stone culture varied, with 4-7 days (46%) and 8-14 days (21%) the most reported. More years in practice was associated with fewer stone cultures ordered, while higher annual volume of percutaneous nephrolithotomy was associated with ordering more stone cultures (p < 0.01). Endourologists have differing practice patterns with respect to ordering stone cultures and utilizing the results to guide post-operative antibiotics. With inconsistent microbiology lab stone culture protocols across multiple institutions, more uniform processing is needed for future studies to assess the clinical benefit of stone cultures and direct future guidelines.

The 2023 Stone-Free CT Mandate: Addressing the Two Sides of the Debate.

To the editors of the Journal of Endourology, we write to express our reservations in the recent announcement that starting in 2023 all reporting of stone-free rates be based on CT.

Removal of Small, Asymptomatic Kidney Stones and Incidence of Relapse.

BACKGROUND: The benefits of removing small (≤6 mm), asymptomatic kidney stones endoscopically is unknown. Current guidelines leave such decisions to the urologist and the patient. A prospective study involving older, nonendoscopic technology and some retrospective studies favor observation. However, published data indicate that about half of small renal stones left in place at the time that larger stones were removed caused other symptomatic events within 5 years after surgery. METHODS: We conducted a multicenter, randomized, controlled trial in which, during the endoscopic removal of ureteral or contralateral kidney stones, remaining small, asymptomatic stones were removed in 38 patients (treatment group) and were not removed in 35 patients (control group). The primary outcome was relapse as measured by future emergency department visits, surgeries, or growth of secondary stones. RESULTS: After a mean follow-up of 4.2 years, the treatment group had a longer time to relapse than the control group (P<0.001 by log-rank test). The restricted mean (±SE) time to relapse was 75% longer in the treatment group than in the control group (1631.6±72.8 days vs. 934.2±121.8 days). The risk of relapse was 82% lower in the treatment group than the control group (hazard ratio, 0.18; 95% confidence interval, 0.07 to 0.44), with 16% of patients in the treatment group having a relapse as compared with 63% of those in the control group. Treatment added a median of 25.6 minutes (interquartile range, 18.5 to 35.2) to the surgery time. Five patients in the treatment group and four in the control group had emergency department visits within 2 weeks after surgery. Eight patients in the treatment group and 10 in the control group reported passing kidney stones. CONCLUSIONS: The removal of small, asymptomatic kidney stones during surgery to remove ureteral or contralateral kidney stones resulted in a lower incidence of relapse than nonremoval and in a similar number of emergency department visits related to the surgery. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and the Veterans Affairs Puget Sound Health Care System; ClinicalTrials.gov number, NCT02210650.).

Evaluation of the Educational Impact of the Urology Collaborative Online Video Didactics Lecture Series.

OBJECTIVE: To assess the impact of the Urology Collaborative Online Video Didactic (COViD) lecture series series on resident knowledge as a supplement to resident education during the coronavirus disease 2019 pandemic. METHODS: One hundred thirty-nine urology residents were voluntarily recruited from 8 institutions. A 20-question test, based on 5 COViD lectures, was administered before and after watching the lectures. Pre- and posttest scores (percent correct) and score changes (posttest minus pretest score) were assessed considering demographic data and number of lectures watched. Multiple linear regression determined predictors of improved scores. RESULTS: Of residents recruited, 95 and 71 took the pre- and posttests. Median number of lectures watched was 3. There was an overall increase in correct scores from pretest to posttest (45% vs 57%, P < .01). Watching any lectures vs none led to higher posttest scores (60% vs 44%, P < .01) and score changes (+16% vs +1%, P < .01). There was an increase in baseline pretest scores by post-graduate year (PGY) (P < .01); however there were no significant differences in posttest or score changes by PGY. When accounting for lectures watched, PGY, and time between lecture and posttest, being a PGY6 (P = .01) and watching 3-5 lectures (P < .01) had higher overall correct posttest scores. Watching 3-5 lectures led to greater score changes (P < .001-.04). Over 65% of residents stated the COViD lectures had a large or very large impact on their education. CONCLUSIONS: COViD lectures improved overall correct posttest scores and increased knowledge base for all resident levels. Furthermore, lectures largely impacted resident education during the coronavirus disease 2019 pandemic.

Human jackstone arms show a protein-rich, X-ray lucent core, suggesting that proteins drive their rapid and linear growth.

Jackstone calculi, having arms that extend out from the body of the stone, were first described over a century ago, but this morphology of stones has been little studied. We examined 98 jackstones from 50 different patient specimens using micro-computed tomography (micro CT) and infrared (IR) spectroscopy. Micro CT showed that jackstone arms consisted of an X-ray lucent core within each arm. This X-ray lucent core frequently showed sporadic, thin layers of apatite arranged transversely to the axis of the arm. The shells of the jackstones were always composed of calcium oxalate (CaOx), and with the monohydrate form the majority or sole mineral. Study of layering in the shell regions by micro CT showed that growth lines extended from the body of the stone out onto jack arms and that the thickness of the shell covering of jack arms often thinned with distance from the stone body, suggesting that the arms grew at a faster radial rate than did the stone body. Histological cross-sections of decalcified jackstone arms showed the core to be more highly autofluorescent than was the CaOx shell, and immunohistochemistry showed the core to be enriched in Tamm-Horsfall protein. We hypothesize that the protein-rich core of a jack arm might preferentially bind more protein from the urine and resist deposition of CaOx, such that the arm grows in a linear manner and at a faster rate than the bulk of the stone. This hypothesis thus predicts an enrichment of certain urine proteins in the core of the jack arm, a theory that is testable by appropriate analysis.

Capturing the Perspective of Prospective Urology Applicants: Impacts of COVID-19 on Medical Education.

OBJECTIVE: To capture the perspective of prospective urology applicants experiencing unique challenges in the context of COVID-19. METHODS: A voluntary, anonymous survey was distributed online, assessing the impact of COVID-19 on a large sample of US medical students planning to apply to urology residencies. Themes of (1) specialty discernment, (2) alterations to medical education, and (3) the residency application process were explored. RESULTS: A total of 238 medical students, 87% third and fourth years, responded to the survey. While 85% indicated that the pandemic had not deterred their specialty choice, they noted substantial impacts on education, including 82% reporting decreased exposure to urology. Nearly half of students reported changes to required rotations and 35% reported changes to urology-specific rotations at their home institutions. Students shared concerns about suspending in-person experiences, including the impact on letters of recommendation (68% "very concerned) and program choice (73% "very concerned"). Looking to the possibility of virtual interactions, students identified the importance of small group and one-on-one communication with residents (83% "very important") and opportunities to learn about hospital facilities (72% "very important"). CONCLUSION: Despite the impacts of COVID-19 on medical education, prospective urology applicants appear to remain confident in their specialty choice. Students' biggest concerns involve disruption of away rotations, including impacts on obtaining letters of recommendation and choosing a residency program.

A Longitudinal Assessment of the Reporting Quality of Randomized Controlled Trials for Surgical Interventions to Treat Nephrolithiasis Over 16 Years (2002 to 2017).

Purpose: Transparently reported, high-quality randomized controlled trials (RCTs) play a critical role in guiding evidence based clinical practice and informing evidence-based guidelines in patients with nephrolithiasis. Prior studies have found reporting quality to be low. We performed this study to assess whether the reporting of RCTs has improved over time. Materials and Methods: This study was governed by an a priori protocol. We performed a systematic literature search for RCTs analyzing nephrolithiasis treatment. Selection of eligible studies and data abstraction were performed by two of three reviewers independently and in duplicate. We developed and pilot tested a data extraction checklist based on the Consolidated Standards of Reporting Trials (CONSORT) criteria on a scale of 0 to 25. Our primary outcome measure was the mean CONSORT score. We performed statistical hypothesis testing to compare scores between 2002-2006, 2007-2011, and 2012-2017. Results: A total of 203 studies (2002-06: 38; 2007-11: 64; 2012-17: 101) met inclusion criteria. The most common procedure types studied were percutaneous nephrolithotomy (35.1%), shockwave lithotripsy (25.4%), and ureteroscopy (22.9%). Asia contributed an increasing proportion of studies (25.6%, 44.6%, and 74.3%, respectively) in these three time periods. The main journals of publication were the Journal of Endourology (23.9%), the Journal of Urology (19.5%), and Urology (8.3%). The mean ± standard error of the CONSORT summary scores was 11.4 ± 0.4, (2002 to 2006), 12.1 ± 0.3, (2007 to 2011), and 13.3 ± 0.4 (p = 0.003) reflecting an increase by 1.92 (95% confidence interval: 0.86 - 2.98). Conclusions: The number of RCTs investigating the use of urologic devices to treat stone disease has substantially increased overtime. There has been a small improvement in reporting quality; however, this remains suboptimal overall. Increased efforts to promote the transparent reporting of RCTs in endourology are warranted.

Multi-Institutional Collaborative Resident Education in the Era of COVID-19.

INTRODUCTION: The 2019-2020 coronavirus pandemic has had a significant impact on all aspects of health care. Decrease in clinical and operative volume and limitations for conferences has drastically decreased educational opportunities for resident trainees. We describe the formation and initial success of the Collaborative Online Video Didactics lecture series, a multi-institutional online video didactics collaboration. METHODS: Zoom data extraction and postlecture evaluation surveys were used to collect data on the impact of the pandemic on local educational activities as well as feedback about the lecture series. Lectures are being given by faculty from 35 institutions. The twice daily, hour-long webinar averages more than 470 live viewers per session with an average of 33.5 questions per session and has over 7,000 YouTube views of the recordings after the first 2 weeks. RESULTS: Viewers reported significant decreases in outpatient (75.2%), inpatient (64.9%) and operating room (77.7%) volumes at local programs, and only half (52.7%) of the survey responders indicated an increase in didactics locally. The lectures have been well-received, with over 90% of respondents giving the lecturers and series above average or excellent ratings. A significant majority of responders indicated that the lecture series has allowed for ongoing education opportunities during the pandemic (95.0%), helped to access faculty experts from other institutions (92.3%) and provided a sense of community connectedness during this period of social isolation (81.7%). CONCLUSIONS: We strongly encourage other institutions and trainees to participate in the didactic series and hope that this series can continue to evolve and be of benefit beyond the pandemic.

Thrombi Within the Urinary Tract May Serve as a Nidus for Rapid Stone Recurrence: A Report of Two Cases.

Background: Nephrolithiasis is increasingly becoming one of the most prevalent and costly urologic conditions in the United States. The most common type of kidney stone in humans is calcium oxalate, accounting for 75% of idiopathic stones in first-time stone formers. Stone formation is typically a gradual process; however, certain factors can accelerate stone development and recurrence. Case Presentation: We present two cases of adult white men who were found to have rapidly recurrent symptomatic kidney stones that were ultimately determined to be comprised of an outer mineral shell with an inner core of blood clot. Both patients had a history of nephrolithiasis and recent hematuria. Urine supersaturation values at time of presentation supported formation of kidney stones. Conclusion: Thrombi within the urinary tract can serve as a nidus for formation of multiple types of kidney stones, including calcium oxalate and uric acid stones. Stones arising from such a nidus may exhibit unusually rapid growth.

In Vivo Renal Tubule pH in Stone-Forming Human Kidneys.

Introduction: There is evidence that patients with a history of ileostomies, who produce acidic urine and form uric acid or calcium oxalate stones, may plug some collecting ducts with calcium phosphate (CaP) and urate crystals. This is a paradoxical finding as such minerals should not form at an acid pH. One possible explanation is the presence of acidification defects due to focal damage to inner medullary collecting duct and Bellini duct (BD) cells. We sought to further investigate this hypothesis through direct measurement of ductal pH in dilated BDs in patients with ileostomies undergoing percutaneous nephrolithotomy (PCNL) for stone removal. Methods: After obtaining institutional review board approval, we used a fiber-optic pH microsensor with a 140-µm-diameter tip to measure intraluminal pH from the bladder, saline irrigant, and dilated BDs of patients undergoing PCNL. Results: Measurements were taken from three patients meeting inclusion criteria. Measured pH of bladder urine ranged from 4.97 to 5.58 and pH of saline irrigant used during surgery ranged from 5.17 to 5.75. BD measurements were achieved in 11 different BDs. Mean intraductal BD pH was more than 1 unit higher than bulk urine (6.43 ± 0.22 vs 5.31 ± 0.22, p < 0.01). Conclusions: This is the first evidence for focal acidification defects within injured/dilated BDs of human kidneys producing highly acidic bulk phase urine. These results may help explain the paradoxical finding of CaP and urate plugs in dilated ducts of patients with stone-forming diseases characterized by highly acidic urine.