Should a Refluxing Internal Diversion Be Considered a Temporizing Procedure? Extended Follow-Up and Outcomes After Side-to-Side Ureterovesicostomy for Primary Obstructive Megaureter in Young Children.

PURPOSE: We describe long-term outcomes, including UTIs and need for reimplantation, after ureterovesicostomy (UV) as a lasting surgical procedure for children with primary obstructive megaureter (POM). MATERIALS AND METHODS: Children referred to our institution between 2016 and 2023 who underwent refluxing UV were analyzed. POM was defined as hydroureteronephrosis with distal ureteral dilatation > 7 mm and a negative workup for other etiologies of hydronephrosis. We assessed for surgical outcomes, complications, rate of UTI, and improvement in upper tract dilatation. Statistical analyses assessed for change in hydronephrosis metrics over follow-up. RESULTS: Among 183 patients diagnosed with POM, 47 (24%) underwent UV. Median age of presentation, surgery, and follow-up was 2, 9, and 43 months, respectively. A total of 7 patients developed 30-day complications: Clavien-Dindo grade 1 in 2 (transient urinary retention) and grade 2 in 5 (UTIs). During monitoring 14 (30%) developed UTIs and 7 (15%) required ureteral reimplant or UV takedown. After surgery there was a significant decrease in the proportion of patients with high-grade hydronephrosis, anteroposterior renal pelvis diameter, and maximum ureteral dilatation. CONCLUSIONS: Refluxing UV is a safe alternative to cutaneous diversion in POM. Most patients had improvement in upper tract dilatation with an acceptable short-term complication rate and need for reoperation (in comparison to routine later reimplantation). Our experience suggests that monitoring alone after UV is feasible, and that selective subsequent reconstruction is a reasonable strategy.

A scoping review on chordee correction in boys with ventral congenital penile curvature and hypospadias.

Introduction: Congenital penile curvature (PC), often concomitant with hypospadias, poses challenges in urology. Surgical correction techniques, including plication and corporotomy, lack standardized guidelines. This study aims to address the paucity of high-level evidence by comprehensively reviewing the outcomes of PC correction procedures in patients with and without hypospadias. This will inform clinical decision-making and provide insights for future research and meta-analyses. Methods: We conducted this scoping review in accordance with the JBI Manual for Evidence Synthesis and PRISMA-ScR guidelines. An extensive literature search was performed and comparative studies published in English up to June 2023 were included. The studies were divided into three categories: PC without hypospadias, PC with hypospadias, and studies comparing two or more materials for covering the ventral corporotomy. Data extraction comprised author details, patient characteristics, study design, interventions, outcomes, and complications. Methodological quality was assessed using the Newcastle-Ottawa Scale. Results: Forty-two studies were included in the review, which collectively comprised 3180 patients. Thirteen comparative studies reported the outcomes of surgery for congenital PC without hypospadias, 22 studies compared different techniques of PC correction in patients with hypospadias and 7 studies compared the type of materials for coverage following ventral corporotomy. In cases of PC without hypospadias, the most commonly reported surgery was the Nesbit's plication. For PC with hypospadias correction, the results of ventral corporotomy were superior to that of dorsal plication in most of the studies. The two-stage repair had better results when compared to the one-stage repair for patients with perineo-scrotal hypospadias. In studies comparing materials for coverage of ventral corporotomy, the tunica vaginalis flap or graft was utilized most commonly. The majority of the studies reported a success rate ranging from 85% to 100%. The methodological quality was high in all but four studies. Conclusion: Plication procedures are generally preferred for PC without hypospadias, but they result in penile shortening. For those with hypospadias, corporotomy is associated with superior outcomes than plication, especially for those with severe curvature and redo procedures. For ventral corporotomy coverage, the tunica vaginalis flap or graft is the most commonly reported tissue in the literature.

Application of STREAM-URO and APPRAISE-AI reporting standards for artificial intelligence studies in pediatric urology: A case example with pediatric hydronephrosis.

INTRODUCTION: Artificial intelligence (AI) and machine learning (ML) in pediatric urology is gaining increased popularity and credibility. However, the literature lacks standardization in reporting and there are areas for methodological improvement, which incurs difficulty in comparison between studies and may ultimately hurt clinical implementation of these models. The "STandardized REporting of Applications of Machine learning in UROlogy" (STREAM-URO) framework provides methodological instructions to improve transparent reporting in urology and APPRAISE-AI in a critical appraisal tool which provides quantitative measures for the quality of AI studies. The adoption of these will allow urologists and developers to ensure consistency in reporting, improve comparison, develop better models, and hopefully inspire clinical translation. METHODS: In this article, we have applied STREAM-URO framework and APPRAISE-AI tool to the pediatric hydronephrosis literature. By doing this, we aim to describe best practices on ML reporting in urology with STREAM-URO and provide readers with a critical appraisal tool for ML quality with APPRAISE-AI. By applying these to the pediatric hydronephrosis literature, we provide some tutorial for other readers to employ these in developing and appraising ML models. We also present itemized recommendations for adequate reporting, and critically appraise the quality of ML in pediatric hydronephrosis insofar. We provide examples of strong reporting and highlight areas for improvement. RESULTS: There were 8 ML models applied to pediatric hydronephrosis. The 26-item STREAM-URO framework is provided in Appendix A and 24-item APPRAISE-AI tool is provided in Appendix B. Across the 8 studies, the median compliance with STREAM-URO was 67 % and overall study quality was moderate. The highest scoring APPRAISE-AI domains in pediatric hydronephrosis were clinical relevance and reporting quality, while the worst were methodological conduct, robustness of results, and reproducibility. CONCLUSIONS: If properly conducted and reported, ML has the potential to impact the care we provide to patients in pediatric urology. While AI is exciting, the paucity of strong evidence limits our ability to translate models to practice. The first step toward this goal is adequate reporting and ensuring high quality models, and STREAM-URO and APPRAISE-AI can facilitate better reporting and critical appraisal, respectively.

The Toronto nomogram: A Bayesian meta-regression derived prenatal ultrasound index to predict lower urinary tract obstruction and prune belly syndrome.

INTRODUCTION: A nomogram for predicting the diagnosis of lower urinary tract obstruction (LUTO) based on an antenatal ultrasound index generated from a Bayesian Meta-regression analysis has been in development and noted with superior diagnostic accuracy compared to the keyhole sign (KHS). We aim to assess the accuracy of the nomogram in expanded diagnostic utilization to predict LUTO. METHODOLOGY: The validation of the nomogram for expanded diagnostic utilization was based on data from a prospective institutional antenatal clinic database between January 2020 and June 2022. Diagnostic accuracy indices were determined for confirmed postnatal diagnosis of LUTO or prune belly syndrome (PBS). Receiver operating characteristics (ROC) curves were generated to compare the area under the curve (AUC) of the nomogram versus KHS. RESULTS: Based on 84 male fetuses with antenatal ultrasound of moderate-severe hydronephrosis (PUV n = 15, PBS n = 4), the KHS had 26.3% (95%CI 9.1-51.2) sensitivity and 100% (95%CI 94.4%-100%) specificity, with 14 false-negatives. The nomogram showed a 84.2 (95%CI 60.4%-96.6%) sensitivity and 95.4 (95%CI 87.1%-99%) specificity with three false-positives. The nomogram also had a superior AUC compared to KHS (0.98 vs. 0.63). CONCLUSION: The nomogram can be used as a valuable tool to trigger further postnatal screening and provide individualized risk assessments to families during prenatal counseling.

Pathological Findings in Fetuses Terminated for Suspected Lower Urinary Tract Obstruction: Experience From a High-Risk Fetal Center in Canada.

PURPOSE: Pregnancies complicated by prenatally suspected lower urinary tract obstruction (LUTO) can be associated with high rates of terminations due to potentially poor outcomes. Herein, we assessed autopsy findings of fetuses terminated for suspected LUTO to evaluate the prenatal diagnostic accuracy and spectrum of underlying pathologies. MATERIALS AND METHODS: We performed a retrospective review of all pregnancies referred to a high-risk fetal center in a universal access to care health care system for suspected LUTO that opted for termination of pregnancy between 2009 and 2022. Ultrasound features, genetic investigations, placental findings, and distribution of postmortem diagnoses were assessed. RESULTS: Of a total of 190 pregnancies with suspected LUTO evaluated during the study period, 79 (42%) were terminated. We excluded 35 fetuses with incomplete data, resulting in 44 available for analysis. Pregnancies were terminated at a mean gestation of 22 ± 5 weeks. A LUTO diagnosis was confirmed in 37 (84.1%) fetuses (35 males, 2 females), and the remaining 7 showed other pathologies. Pulmonary hypoplasia was found in 62.2% (n = 23) and placental pathologies in 56.8% of confirmed LUTO compared to 33.4% and 71.4% in non-LUTO cases, respectively. Overall, a total of 31 fetuses underwent additional prenatal investigations with genetic anomalies detected only in fetuses with a confirmed LUTO diagnosis (13.6%). CONCLUSIONS: In our health care system, almost half of prenatally suspected LUTO pregnancies are terminated. The sonographic diagnostic accuracy for LUTO is reasonable at 84%. However, the remaining 16% still had significant pathologies. Genetic abnormalities are uncommon and rarely the trigger for pregnancy terminations.

Kidney function and transplants in prune belly syndrome: a scoping review.

BACKGROUND: Children with prune belly syndrome (PBS) are at higher risk of developing kidney dysfunction and requiring kidney replacement therapy (KRT). While studies have described surgical and survival outcomes in these populations, there has yet to be a focused synthesis of evidence regarding kidney outcomes in this population. Here, the focus of this scoping review was to highlight knowledge gaps and report standards on kidney outcomes in PBS of all ages. METHODS: Following scoping review methodology, EMBASE, MEDLINE, and Scopus were searched for peer-reviewed literature that describe kidney outcomes in PBS. All studies with a broad set of kidney outcomes (such as kidney function measures, chronic kidney disease (CKD), KRT and associated outcomes) were included. Findings were summarized and qualitatively synthesized. RESULTS: Of the 436 unique records identified, 25 were included for synthesis. A total of 17 studies (441 patients) reported on kidney insufficiency outcomes, with an estimated prevalence of CKD ranging from 8 to 66%. A total of 15 studies (314 patients) described KRT, primary kidney transplant, and outcomes. Of these, the age for KRT ranged from 4 to 21 years, and graft survival ranged from 22 to 87% by last follow-up (range 1.3-27 years). CONCLUSIONS: There is significant variability in studies reporting kidney outcomes in PBS which limits meaningful synthesis. There is a need for future studies with comprehensive reporting of confounders and drivers for kidney insufficiency in PBS.

The urological evaluation and management of neurogenic bladder in children and adolescents-what every pediatric nephrologist needs to know.

Neurogenic bladder (NGB) is an encompassing term that includes multiple causes of bladder dysfunction linked to a congenital or acquired neurological condition that adversely impacts the innervation of the lower urinary tract. Multiple static or progressive conditions can be associated with NGB in pediatric and adolescent patients. Currently, spinal dysraphism (i.e., spina bifida) is one of the most common etiologies, which occurs in 3-4 per 10,000 live births in developed nations. Abnormal bladder dynamics can lead to kidney damage secondary to high pressures or recurrent infections, as well as urinary incontinence. The current management paradigm centers on a proactive approach to preserving kidney function and achieving continence through behavioral, pharmacological, and surgical means. This educational review highlights the key components of urological management to maximize collaboration with pediatric nephrologists.

Predicting obstruction risk using common ultrasonography parameters in paediatric hydronephrosis with machine learning.

OBJECTIVE: To sensitively predict the risk of renal obstruction on diuretic renography using routine reported ultrasonography (US) findings, coupled with machine learning approaches, and determine safe criteria for deferral of diuretic renography. PATIENTS AND METHODS: Patients from two institutions with isolated hydronephrosis who underwent a diuretic renogram within 3 months following renal US were included. Age, sex, and routinely reported US findings (laterality, kidney length, anteroposterior diameter, Society for Fetal Urology [SFU] grade) were abstracted. The drainage half-times were collected from renography and stratified as low risk (<20 min, primary outcome), intermediate risk (20-60 min), and high risk of obstruction (>60 min). A random Forest model was trained to classify obstruction risk, here named the 'Artificial intelligence Evaluation of Renogram Obstruction' (AERO). Model performance was determined by measuring area under the receiver-operating-characteristic curve (AUROC) and decision curve analysis. RESULTS: A total of 304 patients met the inclusion criteria, with a median (interquartile range) age of diuretic renogram at 4 (2-7) months. Of all patients, 48 (16%) were low risk, 102 (33%) were intermediate risk, 156 (51%) were high risk of obstruction based on diuretic renogram. The AERO achieved a binary AUROC of 0.84, multi-class AUROC of 0.74 that was superior to the SFU grade, and external validation (n = 64) binary AUROC of 0.76. The most important features for prediction included age, anteroposterior diameter, and SFU grade. We deployed our application in an easy-to-use application (https://sickkidsurology.shinyapps.io/AERO/). At a threshold probability of 30%, the AERO would allow 66 more patients per 1000 to safely avoid a renogram without missing significant obstruction compared to a strategy in which a renogram is routinely performed for SFU Grade ≥3. CONCLUSIONS: Coupled with machine learning, routine US findings can improve the criteria to determine in which children with isolated hydronephrosis a diuretic renogram can be safely avoided. Further optimisation and validation are required prior to implementation into clinical practice.

Trends in Management of Fetuses with Suspected Lower Urinary Tract Obstruction (LUTO): A High-Risk Fetal and Pediatric Center Experience in a Universal-Access-to-Care System.

INTRODUCTION: Neonates with lower urinary tract obstruction (LUTO) experience high morbidity and mortality associated with the development of chronic kidney disease. The prenatal detection rate for LUTO is less than 50%, with late or missed diagnosis leading to delayed management and long-term sequelae in the remainder. We aimed to explore the trends in prenatal detection and management at a high-risk fetal center and determine if similar trends of postnatal presentations were noted for the same period. METHODS: Prenatal and postnatal LUTO databases from a tertiary fetal center and its associated pediatric center between 2009 and 2021 were reviewed, capturing maternal age, gestational age (GA) at diagnosis, and rates of termination of pregnancy (TOP). Time series analysis using autocorrelation was performed to investigate time trend changes for prenatally suspected and postnatally confirmed LUTO cases. RESULTS: A total of 161 fetuses with prenatally suspected LUTO were identified, including 78 terminations. No significant time trend was found when evaluating the correlation between time periods, prenatal suspicion, and postnatal confirmation of LUTO cases (Durbin-Watson [DW] = 1.99, p = 0.3641 and DW = 2.86, p = 0.9113, respectively). GA at referral was 20.0 weeks (interquartile range [IQR] 12, 35) and 22.0 weeks (IQR 13, 37) for TOP and continued pregnancies (p < 0.0001). GA at initial ultrasound was earlier in terminated fetuses compared to continued (20.0 [IQR 12, 35] weeks vs. 22.5 [IQR 13, 39] weeks, p < 0.0001). While prenatal LUTO suspicion remained consistently higher than postnatal presentations, the rates of postnatal presentations and terminations remained stable during the study years (p = 0.7913 and 0.2338), as were GA at TOP and maternal age at diagnosis (p = 0.1710 and 0.1921). CONCLUSION: This study demonstrated that more severe cases of LUTO are referred earlier and are more likely to undergo TOP. No significant trend was detected between time and prenatally suspected or postnatally confirmed LUTO, highlighting the need for further studies to better delineate factors that can increase prenatal detection.

Fetal urinary tract dilation: What to tell the parents.

Urinary tract dilation (UTD), which refers to the abnormal dilation of the urinary collection system, is the most common finding on prenatal ultrasound and presents with varying severity, presentation, etiology, and prognosis. Prenatal classification and risk stratification aim to prevent postnatal complications, such as urinary tract infections and further kidney dysfunction. Parents expecting a child with UTD should be counseled by a multidisciplinary team consisting of maternal-fetal medicine specialists, and pediatric urology and nephrology providers. This review summarizes the key points in the diagnostic evaluation and management during the prenatal and initial postnatal period, focusing on the information that should be provided to future parents. We address frequently asked parental questions and concerns that our multidisciplinary clinical practice faces.

External validation and reliability assessment of posterior urethral morphology on initial voiding cystourethrogram as a predictor for infants with posterior urethral valves.

INTRODUCTION: The morphology of the bladder and posterior urethra on initial voiding cystourethrogram (VCUG) in posterior urethral valve (PUV) has been proposed as a meaningful early metric for short- and long-term kidney outcomes. Here, we seek to externally validate the proposed association and assess the reliability of PUV morphology characteristics. MATERIALS AND METHODS: We reviewed our institutional database for patients managed for PUV between 2000 and 2022 and included those treated with primary ablation with at least 1 year of follow-up for kidney function. Each VCUG was evaluated by three independent raters for the height-width ratio of the bladder (HW-B), height-width ratio of the posterior urethra (HW-PU), and posterior-anterior urethral ratio (PA-UR), and trabeculation (none, fine, or coarse). We assessed the reliability in these with intra-class coefficient and Fleiss kappa for continuous and categorical data, respectively. We performed univariate analysis with nadir creatinine and five-year follow-up glomerular filtration rate (GFR). RESULTS: In total, 98 patients met inclusion criteria. The median age at diagnosis and ablation was 10 and 21 days, respectively. Patients with nadir creatinine <0.8 mg/dL had higher follow-up GFR (101 vs. 20 ml/min/1.73 m2, p = 0.04), and lower risk of CKD (odds ratio 14.7, p = 0.002). The median value for HW-B was 1.4, median HW-PU was 2.1, and median PA-U was 4.7, There was significant inter-class agreement between all three measures of 0.80, 0.51, and 0.70 (p < 0.001). The inter-rater agreement for bladder trabeculation was fair (Fleiss K = 0.40, p < 0.001). There was no statistically significant correlation between HW-B, HW-PU, PU-A with nadir creatinine (p = 0.07, 0.33, 0.91) or 5-year GFR (0.27, 0.45, 0.62), respectively. DISCUSSION: There is significant interest in determining prognostic factors and metrics in PUV. The morphological characteristics on VCUG are reliable and is available information for all boys diagnosed with PUV, resulting in an attractive metric. While we do not demonstrate correlation with kidney outcomes, VCUG features warrant further attention as prognostic factors in PUV. CONCLUSIONS: PUV morphology on initial VCUG is a reliable metric of lower urinary tract deformity but is not associated with 5-year kidney outcomes.

A quantitative analysis of voiding cystourethrogram features confirms the association between high-grade vesicoureteral reflux with male sex, younger age, and hydronephrosis.

INTRODUCTION: Vesicoureteral reflux (VUR) is commonly diagnosed in the workup of urinary tract infections or hydronephrosis in children. Traditionally, VUR severity is graded subjectively based on voiding cystourethrogram (VCUG) imaging. Herein, we characterized the association between age, sex, and indication for VCUG, by employing standardized quantitative features. METHODS: We included renal units with a high certainty in VUR grade (>80% consensus) from the qVUR model validation study at our institution between 2013 and 2019. We abstracted the following variables: age, sex, laterality, indication for VCUG, and qVUR parameters (tortuosity, ureter widths on VCUG). High-grade VUR was defined as grade 4 or 5 The association between each variable and VUR grade was assessed. RESULTS: A total of 443 patients (523 renal units) were included, consisting of a 48:52 male/female ratio. The median age at VCUG was 13 months. Younger age at VCUG (<6 months) was associated with greater odds of severe VUR (odds ratio [OR] 2.0), and there was a weak correlation between age and VUR grade (ρ=-0.17). Male sex was associated with increased odds of high-grade VUR (OR 2.7). VCUGs indicated for hydronephrosis were associated with high-grade VUR (OR 4.1) compared to those indicated for UTI only. Ureter tortuosity and width were significantly associated with each clinical variable and VUR severity. CONCLUSIONS: Male sex, younger age (<6 months), and history of hydronephrosis are associated with both high-grade VUR and standardized quantitative measures, including greater ureter tortuosity and increased ureteral width. This lends support to quantitative assessment to improve reliability in VUR grading.

The role of circumcision in preventing urinary tract infections in children with antenatal hydronephrosis: Systematic review and meta-analysis.

INTRODUCTION: Circumcision has been reported to reduce the risk of urinary tract infections (UTIs) in boys with antenatal hydronephrosis (HN). Our aim was to compare the incidence of UTIs in circumcised vs. uncircumcised boys with antenatal HN by conducting a systematic review and meta-analysis. STUDY DESIGN: A comprehensive search was performed until December 2022. Comparative studies were evaluated according to Cochrane collaboration recommendations. Assessed measures included: UTIs, continuous antibiotic prophylaxis (CAP) use, renal outcomes, and circumcision complications. Odds ratios (OR) and mean difference with 95% confidence interval (CI) were extrapolated from available data. Random-effects meta-analysis were performed. RESULTS: Twenty-three studies describing 9093 boys with antenatal HN were identified, including 4677 uncircumcised and 4416 circumcised boys. Overall effect estimates demonstrate that circumcised boys have significantly reduced odds of developing any UTI [OR 0.26, 95%CI 0.21, 0.32; p < 0.001]]. In addition, there a significantly reduced odds of developing UTI when circumcised and on CAP [OR 0.19, 95% CI 0.13, 0.30; p < 0.001]. When stratifying by etiology, circumcision reduced the odds of UTI in boys with isolated HN [OR 0.33, 95% CI 0.16, 0.68; p = 0.003], vesicoureteral reflux [OR 0.23, 95% CI 0.13, 0.42; P < 0.00001], or with posterior urethral valves [OR 0.29, 95% CI 0.13, 0.64; p = 0.002]. DISCUSSION: Circumcision reduces the incidence of UTIs in boys with antenatal HN. This review is limited by the varied definitions of UTIs and inconsistent reporting on HN etiology, renal outcomes, and circumcision complications. CONCLUSIONS: Circumcision should be considered in boys with antenatal HN to prevent the risk of developing UTI. Further research is warranted to individualize the prophylactic role of circumcision for patients with HN.

Development and use of machine learning models for prediction of male sling success A proof-of-concept institutional evaluation.

INTRODUCTION: For mild to moderate male stress urinary incontinence (SUI), transobturator male slings remain an effective option for management. We aimed to use a machine learning (ML )-based model to predict those who will have a long-term success in managing SUI with male sling. METHODS: All transobturator male sling cases from August 2006 to June 2012 by a single surgeon were reviewed. Outcome of interest was defined as 'cure': complete dryness with 0 pads used, without the need for additional procedures. Clinical variables included in ML models were: number of pads used daily, age, height, weight, race, incontinence type, etiology of incontinence, history of radiation, smoking, bladder neck contracture, and prostatectomy. Model performance was assessed using area under receiver operating characteristic curve (AUROC), area under precision-recall curve (AUPRC), and F1-score. RESULTS: A total of 181 patients were included in the model. The mean followup was 56.4 months (standard deviation [SD ] 41.6). Slightly more than half (53.6%, 97/181) of patients had procedural success. Logistic regression, K-nearest neighbor (KNN ), naive Bayes, decision tree, and random forest models were developed using ML. KNN model had the best performance, with AUROC of 0.759, AUPRC of 0.916, and F1-score of 0.833. Following ensemble learning with bagging and calibration, KNN model was further improved, with AUROC of 0.821, AUPRC of 0.921, and F-1 score of 0.848. CONCLUSIONS: ML-based prediction of long-term transobturator male sling is feasible. The low numbers of patients used to develop the model prompt further validation and development of the model but may serve as a decision-making aid for practitioners in the future.