Comparison of metabolic parameters between pure-uric acid and mixed-uric acid kidney stone formers.

PURPOSE: We seek to compare clinical and 24-h urine parameters between pure-uric acid (UA) and UA-CaOx stone formers in our practice and explore how any differences in metabolic profiles could suggest different prevention strategies between the two groups. METHODS: We retrospectively reviewed patients with either pure- or mixed-UA nephrolithiasis from 2020 to 2023 at a tertiary care center. We included patients with a 24-h urine collection and a stone analysis detecting any amount of UA. Patients were organized into two cohorts: (1) those with 100% UA stones and (2) < 100% UA stones. Differences in demographic characteristics were compared between pure-UA and UA-CaOx stone formers. Twenty-four hour urine metabolic parameters as well as metabolic abnormalities were compared between the pure-uric acid and mixed-uric acid groups. RESULTS: We identified 33 pure-UA patients and 33 mixed-UA patients. Patient demographics were similar between the groups (Table 1). Pure- and mixed-UA patients had a similar incidence of metabolic syndrome, diabetes, history of stones, and stone burden. Table 1 Demographic and baseline characteristics among pure- and mixed-uric acid stone formers Pure-uric acid stones (n = 33) Mixed-uric acid stones (n = 33) p-value Median age [IQR] 63.00 [58.00-72.50] 63.00 [53.50-68.00] 0.339 Median BMI [IQR] 28.79 [25.81-33.07] 27.96 [25.81-29.55] 0.534 Gender, n (%) 1.000  Male 21 (63.6) 21 (63.6)  Female 12 (36.4) 12 (36.4) Metabolic syndrome, n (%) 17 (51.5) 16 (48.5) 0.806 Diabetes, n (%) 13 (39.4) 12 (36.4) 0.800 History of stones, n (%) 23 (69.7) 22 (66.7) 0.792 Median total stone burden, mm [IQR] 12.00 [6.00-26.50] 13.00 [7.05-20.00] 0.995 Median serum uric acid, mg/dL [IQR] 6.20 [4.80-7.15] 5.90 [4.98-6.89] 0.582 IQR Interquartile range BMI Body Mass Index n number We found the pure-UA cohort to have 24-h lower urine volume (1.53 vs. 1.96 L/day, p = 0.045) and citrate levels (286 vs. 457 mg/day, p = 0.036). UA-CaOx stone formers had higher urinary calcium levels (144 vs. 68 mg/day, p = 0.003), higher urinary oxalate levels (38 vs. 30 mg/day, p = 0.017), and higher median urinary calcium oxalate super-saturation (3.97 vs. 3.06, p = 0.047). CONCLUSIONS: Pure-UA kidney stone formers have different urinary metabolic parameters when compared with UA-CaOx stone formers, thus requiring different and tailored medical management.

Displacement of Lower Pole Stones During Retrograde Intrarenal Surgery Improves Stone-free Status: A Prospective Randomized Controlled Trial.

PURPOSE: Lower pole renal stones are associated with the lowest stone-free status of any location in the urinary tract during retrograde intrarenal surgery. Prior work has suggested displacing lower pole stones to a more accessible part of the kidney to improve stone-free status. We sought to prospectively compare the efficacy of laser lithotripsy in situ vs after displacement during retrograde intrarenal surgery for lower pole stones. MATERIALS AND METHODS: Between July 2017 and May 2022 patients undergoing retrograde intrarenal surgery for lower pole stones were randomized into an in situ or displacement group. Demographics, comorbidities, and operative parameters were documented. Primary outcome was stone-free status, determined by combination of abdominal x-ray and renal ultrasound at 30-day follow-up. Secondary outcomes included operative time, 30-day complications, emergency department visits, and readmissions. RESULTS: A total of 138 patients (69 per group) were enrolled and analyzed. Baseline characteristics were similar between groups. Stone-free status significantly favored the displacement group over the in situ group (95% vs 74%, P = .003, n=62 in each group). Operative time, total laser energy usage, 30-day complications, and 30-day emergency department visits or hospital readmissions were similar between groups. On multivariate analysis only study group allocation was significantly associated with stone-free status (P = .024). CONCLUSIONS: Basket displacement of lower pole stones results in a significantly higher stone-free status compared to in situ lithotripsy. The technique is simple, atraumatic, and requires no additional equipment costs and little additional operative time, making it a practical tool in the treatment of lower pole stones.

Opioid-free percutaneous nephrolithotomy: an initial experience.

INTRODUCTION: The opioid epidemic in the United States is an ongoing public health crisis that is in part fueled by excessive prescribing by physicians. Percutaneous nephrolithotomy (PCNL) is a procedure that conventionally involves opioid prescriptions for adequate post-operative pain control. We aimed to evaluate the feasibility of a non-opioid pain regimen by evaluating post-operative outcomes in PCNL patients discharged without opioids. MATERIALS AND METHODS: As a quality improvement measure to reduce opioid consumption our department began routinely prescribing oral ketorolac instead of oxycodone-acetaminophen for pain control after PCNL. We retrospectively compared patients undergoing PCNL who had received ketorolac prescriptions (NSAID) to those who received oxycodone-acetaminophen prescriptions (NARC). Demographic, operative, and post-operative factors were obtained and compared in both groups. Peri-operative factors and demographics were compared using either Chi-squared tests, Mann-Whitney U tests. Surgical outcomes were compared between the two groups using Chi-squared tests and Fisher's exact tests. Multivariate logistic regression analysis was performed to determine whether ketorolac use was an independent predictor of post-surgical pain-related encounters. Primary outcome was unplanned pain-related healthcare encounters inclusive of office phone calls, unscheduled office visits, and emergency department (ED) visits. Secondary outcome measures were non-pain-related healthcare encounters, hospital readmissions, pain-related rescue medications prescribed, and post-op complications. RESULTS: There were similar demographics and peri-operative characteristics amongst patients in both cohorts. There was no significant difference identified between NSAID and NARC regarding unplanned pain-related encounters (8/70, 11.4% vs. 10/70, 14.3%, p = 0.614). However, NARC experienced more unplanned phone calls (42, 60% vs. 24, 34.3%, p = 0.004). Multivariate analysis revealed only prior stone surgery was predictive of pain-related encounters after PCNL (p = 0.035). CONCLUSION: Our results show that there were no significant differences in pain-related encounters between those who received ketorolac and oxycodone-acetaminophen following PCNL. A non-opioid pathway may mitigate the potential risk associated with opioid prescription without compromising analgesia. Prospective comparative studies are warranted to confirm feasibility.

Drivers of calcium oxalate stone formation in the octogenarian population.

INTRODUCTION: American Urological Association (AUA) guidelines suggest metabolic testing via 24-h urine studies in high-risk, interested first-time stone formers, and recurrent stone formers. If metabolic testing is not available or otherwise not feasible, clinicians may need to utilize empiric therapy. Debility and social barriers, particularly in the elderly population, may limit the practicality of metabolic testing, and therefore, empiric therapy is of particular importance. The aim of this study is to identify whether unique urinary metabolic abnormality profiles exist for octogenarians with calcium oxalate kidney stones, as this may guide empiric stone prevention therapy more precisely in this population. MATERIALS AND METHODS: Patients with calcium oxalate stones from a single academic kidney stone center in New York, NY, were retrospectively identified in our prospectively managed database. Patient data, including demographic, clinical information, and baseline 24-h urine studies, were collected before initiating any treatment. Subjects were stratified by age (≤ 40, 41-59, 60-79, and ≥ 80 years) to compare the metabolic urinary abnormality profiles between octogenarians and other age groups. Subgroup analyses were also performed to compare results by gender and by the presence of underlying kidney dysfunction. Comparative statistical analysis was carried out using Chi-square tests, Mann-Whitney U tests, and t-tests where appropriate. RESULTS: Hypocitraturia, low urine pH, and low urine volume were most common in older patients, particularly in octogenarians. Hypercalciuria, hypernatriuria, and hyperuricosuria were more apparent in younger groups. CONCLUSION: With increasing age, hypocitraturia, low urine pH, and low urine volume were more prevalent on 24-h urine metabolic testing. We hypothesize increased comorbidity, including medical renal disease, polypharmacy, and dehydration are possible factors contributing to this unique profile. We suggest that empiric therapy targeted towards this profile is important in very elderly stone formers in whom 24-h urine testing may not be possible. Increased hydration, increased fruit and vegetable intake, and low-dose alkali therapy are easy measures to accomplish this.

A prospective randomized study evaluating the necessity of narcotics following ureteroscopy for urinary stone disease.

PURPOSE: To evaluate the efficacy of non-narcotic analgesics and preoperative counseling in managing postoperative pain and narcotic use following ureteroscopic laser lithotripsy (URS). METHODS: Adult patients at a single academic center undergoing URS for nephrourolithiasis were recruited. After informed consent, subjects were randomized into three groups: NARC-15 tablets oxycodone-acetaminophen 5/325 mg (A-OXY), 2. NSAID-15 tablets ibuprofen (IBU) 600 mg, 3. CNSL-15 tablets A-OXY, 15 tablets IBU, and preoperative counseling from the surgeon to avoid narcotic if possible. Patients who did not receive an intraoperative stent were excluded. At the time of stent removal subjects completed the Universal Stent Symptom Questionnaire (USSQ), and a pill count was performed. USSQ pain indices were the primary study endpoint. RESULTS: Of 115 patients enrolled, 104 met the primary endpoint and were included in the analysis. No significant differences were noted in patient demographic, clinical, or operative characteristics. No differences were noted in median USSQ pain indices. The CNSL group used a significantly lower median number of A-OXY pills compared to the NARC group (2.4 vs. 5.4, p = 0.001) and less IBU compared to the NSAID group (3.1 vs. 5.9, p = 0.008). No differences in median total pill count, office calls, medication requests, nor ED visits were noted. CONCLUSION: Our data suggest that patients can achieve equivalent postoperative analgesic satisfaction with non-narcotics compared to opiates following URS. Further, counseling patients on postoperative pain before surgery can reduce the total number of postoperative narcotic and non-narcotic medications taken. We suggest surgeons strongly consider omission of narcotic prescriptions following non-complicated URS.

The T-Tilt Position: A Novel Modified Patient Position to Improve Stone-Free Rates in Retrograde Intrarenal Surgery.

PURPOSE: Residual fragments following retrograde intrarenal surgery can lead to future stone episodes. The lower pole of the kidney presents a unique challenge as it is the most difficult location for retrograde intrarenal surgery. We investigated a modified patient position to increase stone-free rate by analyzing presence of residual fragments. We randomized patients into standard position and the T-Tilt position (15° Trendelenburg and 15° airplane away from the surgical side kidney). MATERIALS AND METHODS: In this prospective, randomized study, patients were randomized into the standard or T-Tilt position. Demographics, comorbidities and operative parameters were collected. Stone-free rate was determined with renal ultrasound and x-ray at 1-month followup. Postoperative complications were recorded up to 1 month. Variables were compared using Kruskal-Wallis test for continuous variables and chi-square test for categorical variables. RESULTS: A total of 138 patients were analyzed: 75 standard patients and 63 T-Tilt patients. The groups had similar patient and stone factors. The most common stone position was the lower pole (68.0% standard, 74.6% T-Tilt). Stone-free rates were significantly different: standard position was 76.7% and T-Tilt position was 92.1% (p=0.015). Stone-free rates for isolated lower pole stones were significantly different as well: standard position was 68.2% and T-Tilt position was 95.6% (p <0.001). Clavien-Dindo scores did not differ significantly (p=0.262). CONCLUSIONS: The T-Tilt patient position was associated with higher stone-free rates. It is an atraumatic, cost-effective technique. These results suggest that modifying patient positioning during retrograde intrarenal surgery improves stone-free rates.

The impact of metabolic syndrome components on urinary parameters and risk of stone formation.

PURPOSE: To investigate the relationship between metabolic syndrome (MS) and urinary abnormalities in stone-forming patients. Additionally, to delineate whether severity of urinary derangements is impacted by the number of co-occurring MS components. METHODS: Stone-forming patients who underwent initial metabolic workup prior to medical intervention at a comprehensive stone clinic were retrospectively reviewed and included in the study. Patients were given a six point (0-5) Metabolic Syndrome Severity Score (MSSS) based on the number of co-occurring MS components and split into six respective groups. Baseline clinical characteristics and metabolic profiles were compared between groups. RESULTS: Four-hundred-ninety-five patients were included in the study. Median age and median BMI was 58 years and 27.26 kg/m2, respectively. Several significant metabolic differences were noted, most notably a downward trend in median urinary pH (p < 0.001) and an upward trend in median urinary supersaturation uric acid (p < 0.001) across groups as MSSS increased. Multivariate analysis demonstrated an independent association between higher MSSS and increasing number of urinary abnormalities. A second multivariate analysis revealed that all MS components except hyperlipidemia were independently associated with low urinary pH. Additionally, obesity was independently associated with the greatest number of urinary abnormalities and had the strongest association with hyperuricosuria. CONCLUSIONS: Prior research has attributed the strong association of nephrolithiasis and MS to high prevalence of UA nephrolithiasis and low urinary pH. Our findings indicate that all MS components with the exception of hyperlipidemia were independently associated with low urinary pH suggesting a mechanism independent from insulin resistance.

The Impact of the COVID-19 Pandemic on Urology Residents: a Narrative Review.

PURPOSE OF REVIEW: The COVID-19 pandemic brought unprecedented challenges for urology resident education. In this review, we discuss the pandemic's impact on urology trainees and their education. RECENT FINDINGS: Urology trainees were often redeployed to frontline services in unfamiliar clinical settings. Residents often experienced increased levels of stress, anxiety, and depression. Many programs instituted virtual "check-ins" and formed liaisons with mental health services to foster cohesiveness. Urology trainees experienced the integration of telehealth into the clinical realm. Virtual surgery lectures and simulations were utilized to augment surgical education. Academic governing bodies upheld resident protections and provided dynamic guidance for training requirement throughout the pandemic. Medical students were unable to participate in traditional in-person away rotations and interviews, complicating the residency application process. The COVID-19 pandemic shook the healthcare system and ushered in seismic changes for urology trainees worldwide. Though the longstanding effects of the pandemic remain to be seen, urology residents have demonstrated tremendous resilience and bravery throughout this challenging period, and those qualities will undeniably withstand the test of time.

Well-being and education of urology residents during the COVID-19 pandemic: Results of an American National Survey.

BACKGROUND: The rapid spread of COVID-19 has placed tremendous strain on the American healthcare system. Few prior studies have evaluated the well-being of or changes to training for American resident physicians during the COVID-19 pandemic. We aim to study predictors of trainee well-being and changes to clinical practice using an anonymous survey of American urology residents. METHODS: An anonymous, voluntary, 47-question survey was sent to all ACGME-accredited urology programmes in the United States. We executed a cross-sectional analysis evaluating risk factors of perception of anxiety and depression both at work and home and educational outcomes. Multiple linear regressions models were used to estimate beta coefficients and 95% confidence intervals. RESULTS: Among ~1800 urology residents in the USA, 356 (20%) responded. Among these respondents, 24 had missing data leaving a sample size of 332. Important risk factors of mental health outcomes included perception of access to PPE, local COVID-19 severity and perception of susceptible household members. Risk factors for declination of redeployment included current redeployment, having children and concerns regarding ability to reach case minimums. Risk factors for concern of achieving operative autonomy included cancellation of elective cases and higher level of training. CONCLUSIONS: Several potential actions, which could be taken by urology residency programme directors and hospital administration, may optimise urology resident well-being, morale, and education. These include advocating for adequate access to PPE, providing support at both the residency programme and institutional levels, instituting telehealth education programmes, and fostering a sense of shared responsibility of COVID-19 patients.

Novel immediate/sustained-release formulation of acetaminophen-ibuprofen combination (Paxerol®) for severe nocturia associated with overactive bladder: A multi-center, randomized, double blinded, placebo-controlled, 4-arm trial.

AIM: To determine short-term efficacy and safety of Paxerol®, novel immediate:sustained (50%:50%) release tablets containing 325 mg acetaminophen and 150 mg ibuprofen per tablet. METHODS: One of three dose levels, corresponding to the amounts in 1, 2, and 3 tablets, of Paxerol and placebo were administered for 14 consecutive days to patients with severe nocturia (defined in this study as an average nocturnal voids [NV] ≥2.5) associated with overactive bladder (OAB). Changes in NV, as well as Nocturia Quality of Life (NQOL), duration of first uninterrupted sleep (DFUS), and total hours of nightly sleep (THNS) associated with treatment were assessed. Short-term safety/tolerability was assessed throughout the study and for at least 30 days post-treatment. RESULTS: Paxerol at all three doses reduced NV to a greater degree than placebo (average NV -1.1, -1.4, -1.3 voids for low, mid, and high doses, respectively, vs -0.3 void for placebo). NQOL and THNS were similar between baseline and treatment values in all four groups. There were also no between-group differences. Paxerol at high dose tended to (although not statistical significantly) increase DFUS to a greater degree than placebo (1.2 vs 0.4 h, P = 0.057). There were no treatment related adverse events in any of the four groups. CONCLUSIONS: This study demonstrates short-term efficacy and short-term safety of Paxerol in patients with severe nocturia associated with OAB. The results warrant further investigation of the long-term efficacy and safety of Paxerol in larger patient populations.

Comparison of nocturia etiology in black and white male patients.

INTRODUCTION: Much of what is known about the etiology of nocturia (i.e., nocturnal polyuria [NP], small bladder capacity [SBC], etc.) at the population level stems from the Krimpen study, which enrolled aging males from a homogenous municipality in the Netherlands. Given the higher prevalence of benign prostatic hyperplasia and overactive bladder in black versus white males in population research, we aim to test the hypothesis that black males seeking treatment for lower urinary tract symptoms (LUTS) are more likely to have nocturia owing to SBC. MATERIALS AND METHODS: We retrospectively analyzed 24 hour frequency-volume charts (FVCs) completed by males seeking treatment for LUTS at a Veterans Affairs urology clinic from 2008-2016. Patients were included if they were ≥ 18 years, identified as either Caucasian or African American, and had a complete baseline FVC showing ≥ 1 nocturnal void. Patients were stratified by race and classified as having nocturia owing to SBC (defined by a maximum voided volume < 200 mL or a nocturnal bladder capacity index > 1.3); NP (defined by a nocturnal polyuria index > 0.33); 'mixed' (SBC + NP); or 'other' (neither SBC nor NP). RESULTS: Between white and black patients, 28 (24%) versus 28 (26%) had NP, 32 (27%) versus 33 (30%) had SBC, and 35 (30%) versus 30 (28%) had mixed nocturia. Overall, there was no difference in distribution of underlying etiology by race (p = 0.51). CONCLUSIONS: Our results demonstrate no difference in the etiology of nocturia between black and white males. Accordingly, race should not play a role in the evaluation of patients seeking treatment for nocturia.

Fesoterodine for the Treatment of Nocturnal Urgency in Patients with Overactive Bladder Syndrome: An Analysis of Responders and Nonresponders.

PURPOSE: A recent study demonstrated improvement in nocturnal urgency in patients with overactive bladder when treated with fesoterodine. In the current study we aimed to determine which bladder diary parameters predict the response to fesoterodine in these patients. MATERIALS AND METHODS: Patients with nocturnal urgency completed a 2-week, single-blind placebo run-in followed by 1:1 double-blind randomization to 12 weeks of fesoterodine or placebo. We analyzed bladder diary parameter changes from baseline to week 12, including the actual number of night voids (total number of nocturia episodes), maximum voided volume, nocturnal bladder capacity, Nocturnal Bladder Capacity Index (NBCi) (actual number of night voids - nocturnal urine volume/maximum voided volume - 1), nocturnal urine volume, the nocturia index (nocturnal urine volume/maximum voided volume) and the nocturnal polyuria index (nocturnal urine volume/24-hour volume). Additionally, we analyzed OAB-q (Overactive Bladder Questionnaire) changes. RESULTS: There was a linear relationship between the likelihood of being a responder for NBCi and the nocturia index. Responders had a significant decrease in nocturnal urine volume relative to baseline (-181.7 ml, p <0.01). Neither group showed a significant change in maximum voided volume relative to baseline. There was a significant decrease in NBCi and the nocturia index in responders (-0.82 and -0.61, respectively, each p <0.01). Responders demonstrated improvement in the OAB-q concern, coping, sleep, bother and total score metrics. CONCLUSIONS: Patients with nocturnal urgency secondary to overactive bladder syndrome and low nocturnal bladder capacity with a mismatch between nocturnal urine production and bladder capacity may benefit from fesoterodine. Symptom improvement appears to be mediated by increases in typical rather than maximum nocturnal voided volumes. Symptom improvement was associated with improved quality of life.

Do Foley Catheters Adequately Drain the Bladder? Evidence from CT Imaging Studies.

INTRODUCTION: The Foley catheter has been widely assumed to be an effective means of draining the bladder. However, recent studies have brought into question its efficacy. The objective of our study is to further assess the adequacy of Foley catheter for complete drainage of the bladder. MATERIALS AND METHODS: Consecutive catheterized patients were identified from a retrospective review of contrast enhanced and non-contrast enhanced computed tomographic (CT) abdomen and pelvis studies completed from 7/1/2011-6/30/2012. Residual urine volume (RUV) was measured using 5mm axial CT sections as follows: The length (L) and width (W) of the bladder in the section with the greatest cross sectional area was combined with bladder height (H) as determined by multiplanar reformatted images in order to calculate RUV by applying the formula for the volume (V) of a sphere in a cube:V=(π/6)*(L*W*H). RESULTS: RUVs of 167 (mean age 67) consecutively catheterized men (n=72) and women (n=95) identified by CT abdomen and pelvis studies were calculated. The mean RUV was 13.2 mL (range: 0.0 mL-859.1 mL, standard deviation: 75.9 mL, margin of error at 95% confidence:11.6 mL). Four (2.4%) catheterized patients had RUVs of >50 mL, two of whom had an improperly placed catheter tip noted on their CT-reports. CONCLUSIONS: Previous studies have shown that up to 43% of catheterized patients had a RUV greater than 50 mL, suggesting inadequacy of bladder drainage via the Foley catheter. Our study indicated that the vast majority of patients with Foley catheters (97.6%), had adequately drained bladders with volumes of <50 mL.

Artificial Intelligence for Urology Research: The Holy Grail of Data Science or Pandora's Box of Misinformation?

Introduction: Artificial intelligence tools such as the large language models (LLMs) Bard and ChatGPT have generated significant research interest. Utilization of these LLMs to study the epidemiology of a target population could benefit urologists. We investigated whether Bard and ChatGPT can perform a large-scale calculation of the incidence and prevalence of kidney stone disease. Materials and Methods: We obtained reference values from two published studies, which used the National Health and Nutrition Examination Survey (NHANES) database to calculate the prevalence and incidence of kidney stone disease. We then tested the capability of Bard and ChatGPT to perform similar calculations using two different methods. First, we instructed the LLMs to access the data sets and independently perform the calculation. Second, we instructed the interfaces to generate a customized computer code, which could perform the calculation on downloaded data sets. Results: While ChatGPT denied the ability to access and perform calculations on the NHANES database, Bard intermittently claimed the ability to do so. Bard provided either accurate results or inaccurate and inconsistent results. For example, Bard's "calculations" for the incidence of kidney stones from 2015 to 2018 were 2.1% (95% CI 1.5-2.7), 1.75% (95% CI 1.6-1.9), and 0.8% (95% CI 0.7-0.9), while the published number was 2.1% (95% CI 1.5-2.7). Bard provided discrete mathematical details of its calculations, however, when prompted further, admitted to having obtained the numbers from online sources, including our chosen reference articles, rather than from a de novo calculation. Both LLMs were able to produce a code (Python) to use on the downloaded NHANES data sets, however, these would not readily execute. Conclusions: ChatGPT and Bard are currently incapable of performing epidemiologic calculations and lack transparency and accountability. Caution should be used, particularly with Bard, as claims of its capabilities were convincingly misleading, and results were inconsistent.

Evaluation of the Current Status of Artificial Intelligence for Endourology Patient Education: A Blind Comparison of ChatGPT and Google Bard Against Traditional Information Resources.

Introduction: Artificial intelligence (AI) platforms such as ChatGPT and Bard are increasingly utilized to answer patient health care questions. We present the first study to blindly evaluate AI-generated responses to common endourology patient questions against official patient education materials. Methods: Thirty-two questions and answers spanning kidney stones, ureteral stents, benign prostatic hyperplasia (BPH), and upper tract urothelial carcinoma were extracted from official Urology Care Foundation (UCF) patient education documents. The same questions were input into ChatGPT 4.0 and Bard, limiting responses to within ±10% of the word count of the corresponding UCF response to ensure fair comparison. Six endourologists blindly evaluated responses from each platform using Likert scales for accuracy, clarity, comprehensiveness, and patient utility. Reviewers identified which response they believed was not AI generated. Finally, Flesch-Kincaid Reading Grade Level formulas assessed the readability of each platform response. Ratings were compared using analysis of variance (ANOVA) and chi-square tests. Results: ChatGPT responses were rated the highest across all categories, including accuracy, comprehensiveness, clarity, and patient utility, while UCF answers were consistently scored the lowest, all p < 0.01. A subanalysis revealed that this trend was consistent across question categories (i.e., kidney stones, BPH, etc.). However, AI-generated responses were more likely to be classified at an advanced reading level, while UCF responses showed improved readability (college or higher reading level: ChatGPT = 100%, Bard = 66%, and UCF = 19%), p < 0.001. When asked to identify which answer was not AI generated, 54.2% of responses indicated ChatGPT, 26.6% indicated Bard, and only 19.3% correctly identified it as the UCF response. Conclusions: In a blind evaluation, AI-generated responses from ChatGPT and Bard surpassed the quality of official patient education materials in endourology, suggesting that current AI platforms are already a reliable resource for basic urologic care information. AI-generated responses do, however, tend to require a higher reading level, which may limit their applicability to a broader audience.

Treatment of bilateral encrusted ureteral stents, large volume renal stones, and ureteral stricture in a complex pediatric patient: a surgical video and case review.

Myotonic dystrophy is a debilitating genetic disease that carries a predilection for a variety of comorbidities. Kidney stone disease in this population can present a variety of unique challenges related to patient age, comorbidities, and social factors. We present a video review case of a 13-year-old girl with myotonic dystrophy who was treated surgically for large bilateral stone burden, bilateral retained ureteral stents with nephrostomy tubes, and right ureteral stricture. The patient had multiple prior urologic procedures and recurrent admissions for infection prior to presentation. Preoperative planning included non-contrast CT imaging, admission to an intensive care unit, and multidisciplinary discussion of treatment and goals. Through combined antegrade and retrograde approaches, the patient's stone burden was cleared, right ureteral stricture was treated, and all tubes were able to be removed in two major procedures and one minor cystoscopy with stent removal under anesthesia. Early referral to tertiary care centers and involvement of multiple specialist teams may help reduce perioperative risk and minimize the number of surgeries. Additionally, patients at high anesthesia risk may benefit from concurrent percutaneous nephrolithotomy with endopyelotomy.

Comprehensive analysis of factors associated with significant blood loss during percutaneous nephrolithotomy.

INTRODUCTION: The objective of this study is to conduct a thorough investigation of the risk factors associated with blood loss during PCNL, within the setting of a US urban tertiary care center. MATERIALS AND METHODS: We conducted a retrospective analysis of our endourology database to identify adult patients who underwent PCNL for stone extraction at our tertiary stone center between October 2014 and December 2022. Patients were categorized into two groups based on the extent of blood loss: significant blood loss (SBL) and no significant blood loss (NSBL). The cut-off value for SBL was determined as the median change in hematocrit levels from preoperative to postoperative among patients who required postoperative transfusions. Several factors were evaluated, including stone dimensions, operative details, the presence of preoperative drains, patient position, type of access, access site, number of accesses, tract size, tract length, stone location, number of stones, operative time, and the S.T.O.N.E. Nephrolithometry Scoring System. RESULTS: Our analysis included a total of 695 procedures performed on 674 distinct patients who met our inclusion criteria. Of these, 102 patients (14.7%) were included in the SBL group. Patients in the SBL group had a higher mean number of accesses (1.57 vs. 1.29, P<0.001), were positioned prone more often (96.0% vs. 88.6%, P = 0.025), and underwent fluoroscopic-guided access more frequently (89.9% vs. 64.8%, P<0.001). Additionally, significant differences were observed in stone morphology, with the SBL group having higher rates of complete staghorn stones (42.2% vs. 27.0%, P = 0.019) and lower rates of partial staghorn stones (27.7% vs. 36.8%, P = 0.019). A larger proportion of patients in the SBL group required a 16 French nephrostomy tube for postoperative drainage (13.3% vs. 10.4%, P = 0.041). Lastly, the SBL group had a longer mean operative time compared to the NSBL group (P<0.001). Multiple logistic regression analysis identified stone volume (P = 0.039), number of accesses (P = 0.047), and operative time (P = 0.006) as independent risk factors associated with SBL status. CONCLUSION: Surgical complexity factors such as stone volume, number of accesses, and operative time are linked to a higher risk of SBL during PCNL. Stone volume and the requirement for multiple accesses can usually be estimated with reasonable accuracy before surgery.