Use of ChatGPT in Urology and its Relevance in Clinical Practice: Is it useful?

PURPOUSE: One of the many artificial intelligence based tools that has gained popularity is the Chat-Generative Pre-Trained Transformer (ChatGPT). Due to its popularity, incorrect information provided by ChatGPT will have an impact on patient misinformation. Furthermore, it may cause misconduct as ChatGPT can mislead physicians on the decision-making pathway. Therefore, the aim of this study is to evaluate the accuracy and reproducibility of ChatGPT answers regarding urological diagnoses. MATERIALS AND METHODS: ChatGPT 3.5 version was used. The questions asked for the program involved Primary Megaureter (pMU), Enuresis and Vesicoureteral Reflux (VUR). There were three queries for each topic. The queries were inserted twice, and both responses were recorded to examine the reproducibility of ChatGPT's answers. Afterwards, both answers were combined. Finally, those rwere evaluated qualitatively by a board of three specialists. A descriptive analysis was performed. RESULTS AND CONCLUSION: ChatGPT simulated general knowledge on the researched topics. Regarding Enuresis, the provided definition was partially correct, as the generic response allowed for misinterpretation. For VUR, the response was considered appropriate. For pMU it was partially correct, lacking essential aspects of its definition such as the diameter of the dilatation of the ureter. Unnecessary exams were suggested, for Enuresis and pMU. Regarding the treatment of the conditions mentioned, it specified treatments for Enuresis that are ineffective, such as bladder training. Therefore, ChatGPT responses present a combination of accurate information, but also incomplete, ambiguous and, occasionally, misleading details.

Role of a Preoperative Catheter Regimen in Achieving Early Primary Endoscopic Valve Ablation in Neonates with Posterior Urethral Valves.

PURPOSE: Primary valve ablation is preferred to vesicostomy in the initial management of posterior urethral valves. However, some neonates have a prohibitively small urethra. We describe our experience with a preoperative urethral catheter regimen to enhance the likelihood of neonatal valve ablation. MATERIALS AND METHODS: We performed a retrospective review of 126 neonates with posterior urethral valves treated between 2003 and 2019 with valve ablation prior to 10 weeks of age. The preoperative indwelling catheter either was gradually upsized to an 8Fr (progressive urethral dilation), was not upsized (nondilated) or was initially larger bore (8Fr only). The primary outcome was the ability to perform primary ablation by neonatal resectoscope. The secondary objective was to establish the parameters for considering progressive urethral dilation as well as its associated risks. RESULTS: Overall 97% could be ablated. The progressive urethral dilation group had the lowest mean weight (p <0.001). Only a larger catheter at the time of ablation was significantly associated with feasible ablation (p <0.001) and not urethral dilation, the infant's weight or his gestational age. Progressive urethral dilation was associated with a longer duration of catheterization as well as double the rate of febrile urinary tract infections (8.5%) over the nondilated group (3.6%). CONCLUSIONS: A much higher rate of primary ablation is feasible (97%) than previously reported (82%). More important than the infant's weight is whether a 6Fr to 8Fr catheter is in place at ablation. If an initial 6Fr to 8Fr catheter cannot be placed, urethral dilation to 8Fr should be performed before attempting ablation. This is both a technique and preoperative assessment that is useful for operative planning.

Did COVID-19 Affect Time to Presentation in the Setting of Pediatric Testicular Torsion?

OBJECTIVES: To determine if boys with acute testicular torsion, a surgical emergency requiring prompt diagnosis and treatment to optimize salvage of the testicle, delayed presentation to a medical facility and experienced an extended duration of symptoms (DoS), and secondarily, a higher rate of orchiectomy, during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Single-center, descriptive retrospective chart review of boys presenting with acute testicular torsion from March 15, to May 4, 2020 ("during COVID-19" or group 2), as well as for the same time window in the 5-year period from 2015 to 2019 ("pre-COVID-19" or group 1). RESULTS: A total of 78 boys met inclusion criteria, group 1 (n = 57) and group 2 (n = 21). The mean age was 12.86 ± 2.63 (group 1) and 12.86 ± 2.13 (group 2). Mean DoS before presentation at a medical facility was 23.2 ± 35.0 hours in group 1 compared with 21.3 ± 29.7 hours in group 2 (P < 0.37). When DoS was broken down into acute (<24 hours) versus delayed (≥24 hours), 41 (71.9%) of 57 boys in group 1 and 16 (76.2%) of 21 boys in group 2 presented within less than 24 hours of symptom onset (P < 0.78). There was no difference in rate of orchiectomy between group 1 and group 2 (44.7% vs 25%, P < 0.17), respectively. CONCLUSIONS: Boys with acute testicular torsion in our catchment area did not delay presentation to a medical facility from March 15, to May 4, 2020, and did not subsequently undergo a higher rate of orchiectomy.

Predicting Breakthrough Urinary Tract Infection: Comparative Analysis of Vesicoureteral Reflux Index, Reflux Grade and Ureteral Diameter Ratio.

PURPOSE: The vesicoureteral reflux index is a simple, validated tool for predicting resolution of reflux. Along with likelihood of spontaneous resolution identification of children at risk for febrile urinary tract infection impacts management. We evaluated the usefulness of the vesicoureteral reflux index as a predictive factor for breakthrough febrile urinary tract infection compared to reflux grade and distal ureteral diameter ratio. MATERIALS AND METHODS: Children with primary vesicoureteral reflux and detailed voiding cystourethrogram data were identified. A 1 to 6-point index was assigned, and ureteral diameter ratio was computed by measuring largest ureteral diameter within the pelvis and dividing by the distance between L1 to L3 vertebral bodies. Random forest modeling and logistic multivariable regression were employed to estimate the predictive ability of grade, ureteral diameter ratio and vesicoureteral reflux index with regard to breakthrough febrile urinary tract infection. RESULTS: We analyzed 94 girls and 45 boys with a mean±SD age of 5.4±4.7 months at diagnosis. Mean±SD length of followup was 32.1±24.5 months. A total of 13 children (9.4%) experienced breakthrough febrile urinary tract infection. On univariate analysis ureteral diameter ratio (p=0.01) and vesicoureteral reflux index (p=0.0005) were associated with breakthrough urinary tract infection, while grade (p=0.09) did not reach significance. Area under the curve was generated as a measure of accuracy for each variable and was 0.77 for the vesicoureteral reflux index, 0.71 for ureteral diameter ratio and 0.68 for grade, indicating superiority of the vesicoureteral reflux index for predicting breakthrough febrile urinary tract infection. CONCLUSIONS: Children with higher vesicoureteral reflux index are at increased risk for breakthrough febrile urinary tract infection independent of reflux grade. The vesicoureteral reflux index provides valuable prognostic information about infection risk, facilitating improved clinical decision making.

Accuracy of subjective vesicoureteral reflux timing assessment: supporting new voiding cystourethrogram guidelines.

BACKGROUND: Bladder volume at the onset of vesicoureteral reflux (VUR) is an important prognostic indicator of spontaneous resolution and the risk of pyelonephritis. OBJECTIVE: We aim to determine whether pediatric urologists and pediatric radiologists can accurately estimate the timing of reflux by examining voiding cystourethrogram (VCUG) images without prior knowledge of the instilled contrast volume. MATERIALS AND METHODS: Total bladder volume and the volume at the time of reflux were collected from VCUG reports to determine the volume at the onset of VUR. Thirty-nine patients were sorted into three groups: early-/mid-filling reflux, late-filling and voiding only. Thirty-nine images were shown to three pediatric urologists and two pediatric radiologists in a blinded fashion and they were then asked to estimate VUR timing based on the above categories. A weighted kappa statistic was calculated to assess rater agreement with the gold standard volume-based report of VUR timing. RESULTS: The mean patient age at VCUG was 3.1±2.9 months, the median VUR was grade 3, and 20 patients were female. Overall agreement among all five raters was moderate (k=0.43, 95% confidence interval [CI] 0.36-0.50). Individual agreement between rater and gold standard was slight to moderate with kappa values ranging from 0.13 to 0.43. CONCLUSION: Pediatric radiologists and urologists are unable to accurately and reliably characterize VUR timing on fluoroscopic VCUG. These findings support the recently published American Academy of Pediatrics protocol recommending the routine recording of bladder volume at the onset of VUR as a standard component of all VCUGs to assist in a more accurate assessment of the likelihood of resolution and risk of recurrent urinary tract infections.

Evolving surgical management of pediatric vesicoureteral reflux: is open ureteral reimplantation still the 'Gold Standard'?

Vesicoureteral reflux, the retrograde flow of urine from the bladder into the upper urinary tract, is one of the most common urologic diagnoses in the pediatric population. Once detected, therapeutic options for urinary reflux are diverse, ranging from observation with or without continuous low-dose prophylactic antibiotics to a variety of operative interventions. While a standardized algorithm is lacking, it is generally accepted that management be tailored to individual patients based on various factors including age, likelihood of spontaneous resolution, risk of subsequent urinary tract infections with renal parenchymal injury, and parental preference. Anti-reflux surgery may be necessary in children with persistent reflux, renal scarring or recurrent pyelonephritis after optimization of bladder and bowel habits. Open, laparoscopic/robot-assisted and endoscopic approaches are all successful in correcting reflux and have been shown to reduce the incidence of febrile urinary tract infections.

National Trends in the Management of Primary Vesicoureteral Reflux in Children.

PURPOSE: In September 2011 the AAP (American Academy of Pediatrics) released updated guidelines for the evaluation of children 2 to 24 months old with a febrile urinary tract infection. We documented the impact of the guideline on diagnosis and surgical management of vesicoureteral reflux at U.S. children's hospitals. We hypothesized that voiding cystourethrogram studies and the vesicoureteral reflux treatment rate decreased concurrent with the national guideline release. MATERIALS AND METHODS: The Pediatric Health Information System was queried for children (younger than 18 years) with primary vesicoureteral reflux and their antireflux surgical history from January 2004 to June 2015. Voiding cystourethrogram orders were recorded. Interrupted time series analysis quantified trends surrounding several seminal vesicoureteral reflux publications (2007) and guideline publication (2011). RESULTS: A total of 43,341 voiding cystourethrogram encounters (male 23,946 [55.3%]) were identified for patients at a median age of 3 months (IQR 1-20). For all children monthly voiding cystourethrogram orders increased (+1.0 to +1.6 encounters per month, p <0.034) to September 2011, then sharply declined by 106 encounters per month from September to October 2011 (p <0.001) then did not change significantly (p=0.096, R2=0.79). For those children 2 to 24 months old with a urinary tract infection (3,379 records; male 1,384 [41.0%], median age 4 months [IQR 3-7]) voiding cystourethrograms gradually increased from January 2007 to September 2011 (+0.1 encounters per month, p=0.036), then similarly decreased by 21 encounters per month from September to October 2011 (p <0.001), then did not change significantly (p=0.064, R2=0.78). Overall 28,484 procedures for primary vesicoureteral reflux were identified (male 5,950 [20.9%], median age 4.8 years [IQR 2.5-7.2]). Total surgical procedures did not change significantly until October 2011, then declined (-1.5 procedures per month, p <0.001, R2=0.66). CONCLUSIONS: The number of voiding cystourethrograms ordered nationally in all children and those with a urinary tract infection decreased sharply with the 2011 AAP urinary tract infection guideline release and did not change thereafter. A steady decline in procedures for primary vesicoureteral reflux occurred after October 2011.

Vesicoureteral Reflux Index: Predicting Primary Vesicoureteral Reflux Resolution in Children Diagnosed after Age 24 Months.

PURPOSE: The Vesicoureteral Reflux Index is a validated tool that reliably predicts spontaneous resolution of reflux or at least 2 grades of improvement for patients diagnosed before age 24 months. We evaluated the Vesicoureteral Reflux Index in children older than 2 years. MATERIALS AND METHODS: Patients younger than 18 years who were diagnosed with primary vesicoureteral reflux after age 24 months and had undergone 2 or more voiding cystourethrograms were identified. Disease severity was scored using the Vesicoureteral Reflux Index, a 6-point scale based on gender, reflux grade, ureteral abnormalities and reflux timing. Proportional subdistribution hazard models for competing risks identified variables associated with resolution/improvement at different time points. RESULTS: A total of 21 males and 250 females met inclusion criteria. Mean ± SD age was 4.0 ± 2.1 years and patients had a median vesicoureteral reflux grade of 2. The Vesicoureteral Reflux Index score improved by 1 point in 1 patient (100%), 2 points in 25 (67.6%), 3 points in 48 (37%), 4 points in 18 (21.4%) and 5 to 6 points in 4 (18.2%). Female gender (p = 0.005) and vesicoureteral reflux timing (late filling, p = 0.002; early/mid filling, p <0.001) independently predicted nonresolution. Median resolution time based on Vesicoureteral Reflux Index score was 2 months or less in 15.6% of patients (95% CI 11.0-13.8), 3 months in 34.7% (95% CI 25.4-44.1), 4 months in 55.9% (95% CI 40.1 to infinity) and 5 months or more in 30.3% (95% CI 29.5 to infinity). High grade (IV or V) reflux was not associated with resolution at any point. Ureteral abnormalities were associated with lack of resolution in the first 12 to 18 months (HR 0.29, 95% CI 0.29-0.80) but not in later followup. Vesicoureteral Reflux Index scores of 3, 4 and 5 were significantly associated with lack of resolution/improvement compared to scores of 2 or less (p = 0.031). CONCLUSIONS: The Vesicoureteral Reflux Index reliably predicts primary vesicoureteral reflux improvement/resolution in children diagnosed after age 24 months. Spontaneous resolution/improvement is less likely as Vesicoureteral Reflux Index score and time from diagnosis increase.

Surgical Scar Location Preference for Pediatric Kidney and Pelvic Surgery: A Crowdsourced Survey.

PURPOSE: The benefits of minimally invasive surgery in pediatric urology, such as reduced length of hospital stay and postoperative pain, are less predictable compared to findings in the adult literature. We evaluated the choices that adult patients make for themselves and their children regarding scar location. MATERIALS AND METHODS: We surveyed the preference for scar location/size based on surgery for bladder and kidney procedures with additional questions assessing the impact of a hidden incision, length of hospital stay and pain. The survey was posted to Amazon® Mechanical Turk®. RESULTS: We analyzed a total of 954 completed surveys. Surgical history was reported in 660 surveys (69%) with scar bother reported in 357 (54.2%). For pelvic surgery the initial choice was a Pfannenstiel incision for 434 respondents (45.5%), laparoscopy port incisions for 392 (41.1%) and no preference for incision location for 126 (13.2%). When incisions were illustrated relative to undergarments, 718 respondents (75.3%) chose Pfannenstiel. For kidney surgery 567 respondents (59.4%) initially chose the dorsal lumbotomy incision, 170 (17.8%) chose a flank incision, 105 (11.0%) chose laparoscopy ports and 110 (11.5%) had no preference. Respondents were told that minimally invasive surgery might result in less pain/length of hospital stay and were asked to restate the incision choice. For pelvic surgery 232 of 434 respondents (53.5%) who had chosen Pfannenstiel and 282 of 394 (71.6%) who had chosen laparoscopy remained consistent (p <0.001). For kidney surgery 96 respondents (56.5%) who chose a flank incision, 322 (56.8%) who chose dorsal lumbotomy and 68 (64.2%) who chose laparoscopy remained consistent (p = 0.349). Agreement between the incision choice by respondent as a child and for a child was 82% (κ = 0.69) for pelvic surgery and 84.6% (κ = 0.75) for kidney surgery. CONCLUSIONS: The smallest incision is not always the patient preferred incision, particularly in childhood when pain, length of hospital stay and blood loss may be equivocal among approaches. Discussion of surgical treatment options should include scar length, location and relationship to undergarments.

Vesicoureteral Reflux Index: 2-Institution Analysis and Validation.

PURPOSE: The vesicoureteral reflux index is a novel tool designed to predict spontaneous reflux resolution in infants younger than 2 years. We performed a multi-institutional validation study to confirm the discriminatory power of the vesicoureteral reflux index to predict the vesicoureteral reflux resolution rate in young children. MATERIALS AND METHODS: We identified patients diagnosed with primary vesicoureteral reflux before age 24 months who had 2 or more voiding cystourethrograms available. Demographics, vesicoureteral reflux grade and timing, ureteral anomalies and radiographic outcomes were evaluated. The C-index was estimated for time to event model assessment. RESULTS: A total of 219 girls and 150 boys met study inclusion criteria. Mean ± SD age at diagnosis was 4.7 ± 4.9 months. Of the patients 101 (27.4%) had early to mid filling, 214 (58%) had late filling and 54 (14.6%) had voiding only vesicoureteral reflux. High grade reflux was present in 87 patients (23.6%) and ureteral anomalies were observed in 50 (13.6%). A vesicoureteral reflux index of 1, 2, 3, 4 and 5 or greater showed an improvement/resolution rate of 88.2%, 77.3%, 62.3%, 32.1% and 14.3%, respectively. On time to event analysis children with filling phase vesicoureteral reflux (p <0.001), grade 4-5 reflux (p <0.001) and ureteral anomalies (p = 0.003) had significantly longer median time to resolution. Median time to spontaneous resolution was 12.6, 12.7, 15.1, 25.6 and 31 months or greater for a vesicoureteral reflux index of 1, 2, 3, 4 and 5 or greater, respectively (C-index 0.305, 95% CI 0.252-0.357). During the study period 65 patients (17.6%) underwent surgical intervention. CONCLUSIONS: The vesicoureteral reflux index is a simple tool that reliably predicts significant improvement and spontaneous resolution of primary reflux in patients diagnosed at younger than 2 years. The index provides valuable prognostic information, facilitating individualized patient care.

Urodynamic catheter moisture sensor: A novel device to improve leak point pressure detection.

AIMS: High-quality urodynamic studies in patients with neurogenic lower urinary tract dysfunction are important, as UDS may be the only reliable gauge of potential risk for upper tract deterioration and the optimal tool to guide lower urinary tract management. Reliance on direct visualization of leakage during typical UDS remains a potential source of error. METHODS: Given the necessity of accurate leak point pressures, we developed a wireless leak detection sensor to eliminate the need for visual inspection during UDS. RESULTS: A mean decrease in detrusor leak point pressure of 3 cm/H2 0 and a mean 11% decrease in capacity at leakage was observed when employing the sensor compared to visual inspection in children undergoing two fillings during a single UDS session. CONCLUSION: Removing the visual inspection component of UDS may improve accuracy of pressure readings. Neurourol. Urodynam. 35:647-648, 2016. © 2015 Wiley Periodicals, Inc.

Early effect of American Academy of Pediatrics Urinary Tract Infection Guidelines on radiographic imaging and diagnosis of vesicoureteral reflux in the emergency room setting.

PURPOSE: In 2011 the AAP revised practice parameters on febrile urinary tract infection in infants and children 2 to 24 months old. New imaging recommendations invigorated the ongoing debate regarding the diagnosis and management of vesicoureteral reflux. We compared evaluations in these patients with febrile urinary tract infection before and after guideline publication. MATERIALS AND METHODS: During 2 separate 6-month periods 350 patients 2 to 24 months old were evaluated in the emergency room setting. Demographics, urine culture, renal-bladder ultrasound, voiding cystourethrogram and admission status were assessed. RESULTS: A total of 172 patients presented with initial febrile urinary tract infection in 2011, of whom 47 (27.3%) required hospitalization, while 42 of 178 (23.6%) were admitted in 2012. Admission by year did not significantly differ (p = 0.423). After guideline revision 41.2% fewer voiding cystourethrograms were done (72.1% of cases in 2011 vs 30.9% in 2012, p <0.001). A 17.2% decrease in renal-bladder ultrasound was noted (75.6% in 2011 vs 58.4% in 2012, p <0.001). Of 55 voiding cystourethrograms 21 (38.2%) were positive in 2012 compared to 36.3% in 2011 (p = 0.809). Mean ± SD maximum vesicoureteral reflux grade was unchanged in 2011 and 2012 (2.9 ± 1.2 and 2.5 ± 0.93, respectively, p = 0.109). There was no association between abnormal renal-bladder ultrasound and voiding cystourethrogram positivity (p = 0.116). CONCLUSIONS: AAP guidelines impacted the treatment of infants and young children with febrile urinary tract infection. We found no relationship between renal-bladder ultrasound and abnormal voiding cystourethrogram, consistent with previous findings that call ultrasound into question as the determinant for additional imaging. Whether forgoing routine voiding cystourethrogram results in increased morbidity is the subject of ongoing study.

Emergency Hospital Admissions for Initial Febrile Urinary Tract Infection: Do Patient Demographics Matter?

BACKGROUND: In 2011, the American Academy of Pediatrics revised practice parameters regarding febrile urinary tract infection (fUTI) in children aged 2-24 months. The Section on Urology opposed the omission of voiding cystourethrogram (VCUG), and expressed concern that potential untoward consequences of deferring VCUG may be most felt by children on Medicaid. OBJECTIVE: We ascertained imaging and characteristics of children presenting to the Emergency Department (ED) with initial fUTI to determine the impact of patient demographics on admissions for pyelonephritis. METHODS: Children aged 2-24 months presenting to the ED with initial fUTI were identified. Demographics, insurance status, laboratory studies, renal-bladder ultrasound (RBUS), VCUG, and hospital admission status were evaluated. RESULTS: Three-hundred fifty patients met inclusion criteria; 88 (25.1%) were admitted. Admitted patients were significantly (p < 0.001) younger (mean 0.31 ± 0.33 years) than those managed as outpatients (mean 0.91 ± 0.7 years). On univariate analysis, male gender (p < 0.001), Medicaid insurance (p < 0.05), and non-Hispanic race (p < 0.05) were associated with admission. Race retained significance on multivariate analysis; Caucasian children were 2.35 times (95% confidence interval [CI] 0.79-7.23) and African-American children 3.8 times more likely to be admitted than Hispanic patients (95% CI 1.88-7.63). Children with abnormal RBUS were 12.8 times more likely to require admission (95% CI 4.44-37.0). Medicaid was also independently predictive of admission; such patients were 2.6 times more likely to be admitted than those with private insurance (95% CI 1.15-5.88). CONCLUSIONS: Abnormal ultrasound, non-Hispanic race, and public insurance were strongly associated with hospital admission in children presenting to the ED with initial febrile urinary tract infection.

The dilemma of adolescent varicocele.

Adolescent varicocele is associated with ipsilateral testicular hypotrophy and the concern for future infertility. A testicular size discrepancy greater than 15-20 % between left and right testicle is an indication for treatment to allow catch-up growth in the hope of preventing a future decline in fertility. Some authors advocate for a period of watchful waiting, as normal testicular growth may occur asymmetrically. We review the current literature to highlight some controversies and challenges in management.

Temporal pattern of vesicoureteral reflux on voiding cystourethrogram correlates with dynamic endoscopic hydrodistention grade of ureteral orifice.

PURPOSE: The double hydrodistention implantation technique uses ureteral hydrodistention to visualize injection site(s) and determine required bulking agent volume. Along with grade, early vesicoureteral reflux on voiding cystourethrogram provides prognostic information regarding spontaneous resolution of reflux. We hypothesized that reflux timing is predictive of endoscopic hydrodistention grade. MATERIALS AND METHODS: We identified children undergoing the double hydrodistention implantation technique for primary vesicoureteral reflux between 2009 and 2012. Hydrodistention grade (0 to 3) was assigned prospectively, and compared to vesicoureteral reflux grade and timing on voiding cystourethrogram. RESULTS: A total of 196 children with a mean ± SD age of 3.94 ± 2.58 years underwent injection of 332 ureters. Mean ± SD vesicoureteral reflux grade was 2.8 ± 0.9. Of the ureters 52.4% demonstrated early to mid filling, 39.2% late filling and 8.4% voiding only reflux. Mean ± SD reflux grade was 3.1 ± 0.81 for early filling, 2.6 ± 0.81 for late filling and 2.1 ± 1.1 for voiding only (p <0.0001). Vesicoureteral reflux and hydrodistention grades correlated, with higher reflux grades associated with grade 3 hydrodistention (p <0.001). There was a significant relationship between reflux timing and hydrodistention grade (p <0.001), with a high percentage of ureters with grade 3 hydrodistention displaying early reflux compared to those with grade 1 disease. Significantly increased mean injected volume for ureters with grade 3 hydrodistention (1.6 ml) was observed compared to those with grade 1 or 2 disease (1.25 ml, p <0.001). CONCLUSIONS: Hydrodistention grade correlates with vesicoureteral reflux grade, timing of reflux and injected volume. Early to mid filling vesicoureteral reflux is associated with abnormal hydrodistention (grade 2 to 3). Temporal pattern of vesicoureteral reflux on voiding cystourethrogram may be used to predict ureteral orifice competency and thus aid in predicting resolution of reflux.

Unique Variants of Megacalycosis on Magnetic Resonance Urography.

OBJECTIVE: To present a unique set of patients diagnosed with megacalycosis by magnetic resonance urography (MRU) to re-evaluate the definition of megacalycosis and provide a new perspective on diagnosis and treatment. MATERIALS AND METHODS: A retrospective chart review of patients with megacalycosis as diagnosed by MRU was conducted. MRU was performed to determine the presence of obstruction, further visualize renal anatomy, and clarify the presence of megacalycosis. Patients who were asymptomatic and demonstrated no evidence of obstruction were managed with long-term observation through renal bladder ultrasonography, and symptomatic patients who showed evidence of obstruction (crossing vessels, abnormal renal transit time, or disparity in differential renal function of <40%) were treated surgically with a dismembered Anderson-Hynes pyeloplasty. RESULTS: Thirteen cases of megacalycosis were identified as diagnosed by MRU at our institution between 2007 and 2020. In 7 patients (54%), MRU revealed the simultaneous occurrence of obstruction and megacalycosis. In patients with obstruction (N = 7), surgical intervention was required to correct the obstruction via robotic pyeloplasty. In patients without obstruction (N = 6), conservative management was performed to monitor megacalycosis through long-term follow-up via routine ultrasounds. CONCLUSION: While megacalycosis has historically referred to the non-obstructive dilatation of the renal calyces, our study presents 7 cases of obstruction occurring simultaneously with megacalycosis as diagnosed by MRU. By expanding the designation of megacalycosis to include patients with obstruction, surgical treatment can be explored to prevent future renal colic and/or renal deterioration in those patients.

Spontaneous vesicoureteral reflux resolution curves based on ureteral diameter ratio.

INTRODUCTION: Various factors influence the clinical course of vesicoureteral reflux (VUR) in the pediatric population. Distal ureteral diameter ratio (UDR) is an objective measure reflective of ureterovesical junction anatomy that has been shown to independently predict both spontaneous resolution and breakthrough febrile urinary tract infection (UTI) in children with primary reflux. UDR resolution curves were created, hypothesizing that a UDR value existed at which spontaneous resolution was unlikely to occur. MATERIALS AND METHODS: UDR was computed by measuring largest ureteral diameter within the pelvis and dividing by the distance between L1-L3 vertebral bodies. Recursive partitioning with 10-fold cross validation methodology for time to event data, utilizing martingale residuals was used to create high and low risk groups based on UDR, and stratified by age at diagnosis and laterality. RESULTS: Three hundred and four patients (226 female, 78 male) were analyzed with a mean age at diagnosis of 1.55 ± 1.98 years. Unilateral reflux (p = 0.02), VUR grades 1-3 (p < 0.001), and lower UDR (p < 0.001) were associated with spontaneous resolution on univariate analysis. UDR values were categorized into risk groups based on recursive partitioning. Low risk patients (those with UDR <0.30) achieved VUR resolution faster and with a continuing rate compared to the high-risk group (≥0.30), which had persistent reflux after 3 years [Summary Figure]. When the 0.30 cutoff was applied randomly to patients in test group, the cutoff significantly discriminated between low and high-risk patients (log rank test p = 0.02). DISCUSSION: Primary VUR is often a self-limiting diagnosis, with conservative management favored in low-risk children, UDR may be used to help distinguish those children who may benefit from intervention. Unlike traditional VUR grading where children with any grade of reflux may spontaneously resolve, there appears to be a consistent UDR cutoff whereby patients are very unlikely to spontaneously resolve, regardless of length of follow-up. Therefore, parents of children with a UDR above the 0.3 cutoff, regardless of VUR grade, may be counselled that VUR is very unlikely to resolve over time - thereby reducing the number of VCUGs and length of time these patients are on prophylactic antibiotic prior to surgical intervention. CONCLUSIONS: Children with primary VUR and a UDR of greater than 0.30 are significantly less likely to spontaneously resolve regardless of length of follow-up, and resolution after 3 years was rare. UDR provides objective prognostic information facilitating individualized patient management.

Decreased percent change in renal pelvis diameter on diuretic functional magnetic resonance urography following administration of furosemide may help characterize unilateral uretero-pelvic junction obstruction.

BACKGROUND: A well-established definition of obstruction in the setting of congenital hydronephrosis is lacking. Multiple imaging modalities and radiographic characteristics or parameters have been described to help confirm the diagnosis of ureteropelvic junction obstruction (UPJO). We sought to evaluate the change in anterior-posterior renal pelvic diameter (APRPD) following furosemide administration in patients with unilateral hydronephrosis and confirmed UPJO on functional magnetic resonance urography (fMRU) who underwent pyeloplasty. MATERIALS AND METHODS: There were 49 patients who met inclusion criteria (11 females, 38 males; average age 2.2 years, SD 3.4 years) from February 2006 to September 2020, diagnosed with unilateral hydronephrosis (SFU Grade 3-4) who underwent fMRU prior to pyeloplasty for confirmed UPJO. 29 of the included patients also underwent a post-pyeloplasty fMRU. A weight-adjusted dose of 1 mg/kg of furosemide (max 20 mg/kg) was administered intravenously. Two board-certified pediatric radiologists measured the APRPD of the obstructed and non-dilated kidneys prior to pyeloplasty and APRPD of the hydronephrotic kidneys on the post-pyeloplasty follow up fMRUs. Measurements were performed on images prior to and approximately 30 min following furosemide injection. RESULTS: The average APRPD before furosemide injection in the obstructed kidney prior to pyeloplasty was 26.3 mm (SD 9.0 mm) compared to the non-dilated (not obstructed) kidney measurement of 5.1 mm (SD 3.6 mm) (p < 0.001). Following administration of furosemide, the average APRPD was 31.4 mm (SD 8.8 mm) in the obstructed kidney, and 7.8 mm (SD 4.1 mm) in the non-dilated kidney (p < 0.001). After pyeloplasty, the pre-furosemide APRPD measurement was 17.8 mm (SD 11 mm), which was significantly less compared to the pre-pyeloplasty APRPD (p < 0.001). The post-pyeloplasty, post-furosemide APRPD measurement was 25.8 mm (SD 12 mm), also significantly less compared to the pre-pyeloplasty measurement (p = 0.02). The changes in APRPD in the obstructed kidney prior to pyeloplasty was 5.1 mm (SD 3.5 mm) and after pyeloplasty was 8 mm (SD 4.6 mm) (p = 0.002). Change in APRPD in the non-dilated kidney was 2.7 mm (SD 2.3 mm). Percent APRPD change in the obstructed kidney was 22.9% (SD 18.5%), which was significantly less than 33.3% (SD 22.1%) in the post-pyeloplasty kidney (p = 0.028) and 82.8% (SD 87.9%) in the non-dilated kidney (p < 0.001). CONCLUSIONS: A relatively smaller change in APRPD on fMRU following administration of furosemide in the setting of UPJO may serve as another predictive characteristic of obstructed kidneys.