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.

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.

The Role of Secondary Conservative Management Strategies in Bladder and Bowel Dysfunction: A Systematic Review and Meta-analysis.

OBJECTIVE: To determine the effect of secondary management strategies in addition to urotherapy on BBD outcomes. STUDY DESIGN: The review protocol was prospectively registered (CRD42023422168). MEDLINE, Embase, Cochrane Central Register of Controlled Trials, CINAHL, Scopus (database initiation until June 2023) were searched. Comparative studies of secondary management strategies versus conventional urotherapy alone were included. Two authors independently screened titles/abstracts and reviewed full-text articles. Two authors extracted data related to study characteristics, methodology, subjects, and results. RESULTS: In this systematic review and meta-analysis of 18 studies and 1228 children, secondary management strategies (home-based education, biofeedback, and physical therapy) were associated with reduced symptom burden, fewer recurrent urinary tract infections, and improved uroflowmetry findings than children treated with solely urotherapy for conservative management. CONCLUSIONS: While there is significant reporting heterogeneity, secondary conservative management strategies such as home education, biofeedback or cognitive behavioral therapy, and physiotherapy-based education are associated with reduced urinary incontinence, infections, and abnormal uroflowmetry findings.

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.

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.

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.

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.

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.

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.

A systematic review of paediatric neurogenic lower urinary tract dysfunction guidelines using the Appraisal of Guidelines and Research Evaluation (AGREE) II instrument.

OBJECTIVE: To examine and critique current international clinical practice guidelines (CPGs) on management of paediatric neurogenic lower urinary tract dysfunction (NLUTD) and assess the applicability of these guidelines to clinical practice. MATERIALS AND METHODS: We conducted a systematic review of all CPGs on NLUTD published in English from the year 2010 to 2022. Six reviewers independently used the Appraisal of Guidelines and Research Evaluation (AGREE) II instrument to appraise all eligible CPGs. This instrument is comprised of 23 items organised into six quality domains. The scores for each item and domain were tabulated for each reviewer and interrater reliability was assessed for each domain using the intraclass correlation coefficient (ICC). RESULTS: Six CPGs were appraised and these included: National Institute for Health and Care Excellence (NICE), European Society for Paediatric Urology, International Children's Continence Society, Irish, Spina Bifida Association (SBA), and International Brazilian Journal of Urology guidelines. They had high mean standardised scores in the domain on 'scope and purpose' and 'clarity of presentation' but had low scores in the domain of 'applicability'. The top three CPGs based on overall score were the NICE, Irish and SBA guidelines and the reviewers had high degree of interrater reliability (ICC 0.912, P < 0.001). The mean scores in various domains for the top three guidelines were 95.8 (scope and purpose), 87.5 (stakeholder involvement), 69.1 (rigour of development), 94.0 (clarity of presentation), 68.4 (applicability), and 59.7 (editorial independence). The diagnostic and treatment recommendations of the top three guidelines were presented. CONCLUSION: The existing CPGs on paediatric NLUTD provide high-quality evidence based recommendations. The NICE, Irish and SBA guidelines were the top three CPGs identified. They scored high on most domains except applicability and editorial independence. These domains need to be considered for future updates to improve the utility.

Posterior urethral valves, pressure pop-offs, and kidney function: systematic review and meta-analysis.

PURPOSE: To determine the role of pressure pop-off mechanisms, including vesicoureteral reflux and renal dysplasia (VURD) syndrome, in determining long-term kidney outcomes in boys with posterior urethral valves (PUV). METHODS: A systematic search was performed in December 2022. Descriptive and comparative studies with a defined pressure pop-off group were included. Assessed outcomes included end-stage renal disease (ESRD), kidney insufficiency (defined as chronic kidney disease [CKD] stage 3 + or SCr > 1.5 mg/dL), and kidney function. Pooled proportions and relative risks (RR) with 95% confidence intervals (CI) were extrapolated from available data for quantitative synthesis. Random-effects meta-analyses were performed according to the study design and techniques. The risk of bias was assessed with the QUIPS tool and GRADE quality of evidence. The systematic review was prospectively registered on PROSPERO (CRD42022372352). RESULTS: A total of 15 studies describing 185 patients with a median follow-up of 6.8 years were included. By the last follow-up, overall effect estimates demonstrate the prevalence of CKD and ESRD to be 15.2% and 4.1%, respectively. There was no significant difference in the risk of ESRD in patients with pop-off compared to no pop-off patients [RR 0.34, 95%CI 0.12, 1.10; p = 0.07]. There was a significantly reduced risk for kidney insufficiency in boys with pop-off [RR 0.57, 95%CI 0.34, 0.97; p = 0.04], but this protective effect was not re-demonstrated after excluding studies with inadequate reporting of CKD outcomes [RR 0.63, 95%CI 0.36, 1.10; p = 0.10]. Included study quality was low, with 6 studies having moderate risk and 9 having a high risk of bias. CONCLUSIONS: Pop-off mechanisms may be associated with reducing the risk of kidney insufficiency, but current certainty in the evidence is low. Further research is warranted to investigate sources of heterogeneity and long-term sequelae in pressure pop-offs.

Implementation of a standardized clinical pathway in a dedicated posterior urethral valves clinic: short-term outcomes.

BACKGROUND: To determine if the implementation of a posterior urethral valves (PUV) clinic and standardized management pathway improves the short-term kidney outcomes of infants with PUV. METHODS: From 2016-2022, 50 consecutive patients were divided into groups after the implementation of the clinic (APUV, n = 29) and before (BPUV, n = 21) during a comparable timeframe. Assessed data included age at initial visit, timing and type of surgery, frequency of follow-up visits, medications, nadir creatinine, and development of CKD/kidney failure. Data are shown as median with interquartile range (IQR) and odds ratios (OR) with 95% confidence interval (CI). RESULTS: APUV had higher rates of prenatal diagnoses (12/29 vs. 1/21; p = 0.0037), earlier initial surgical intervention (8 days; IQR 0, 105 vs. 33 days; IQR 4, 603; p < 0.0001), and higher rates of primary diversions (10/29 vs. 0/21; p = 0.0028). Standardized management led to earlier initiation of alpha blockers (326 days; IQR 6, 860 vs. 991; IQR 149, 1634; p = 0.0019) and anticholinergics (57 days; IQR 3, 860 vs. 1283 days; IQR 477, 1718; p < 0.0001). Nadir creatinine was reached at earlier ages in APUV (105 days; IQR 2, 303 vs. 164 days; IQR 21, 447; p = 0.0192 BPUV). One patient progressed to CKD5 in APUV compared to CKD3, CKD5 and one transplant in BPUV. CONCLUSION: Implementing the PUV clinic with standardized treatment expedited postnatal management and resulted in a higher number of cases detected prenatally, a shift in primary treatment, younger ages at initial treatment, reduced time to nadir creatinine, and timely initiation of supportive medications. A higher resolution version of the Graphical abstract is available as Supplementary information.

Late Kidney Effects of Nephron-Sparing vs Radical Nephrectomy for Wilms Tumor: A Systematic Review and Meta-Analysis.

PURPOSE: We compare differences in long-term kidney function between patients undergoing either radical nephrectomy (RN) or nephron-sparing surgery (NSS) in unilateral and bilateral Wilms tumor (WT), respectively. MATERIALS AND METHODS: A systematic search was performed in September 2020. Comparative studies were evaluated according to Cochrane collaboration recommendations. Assessed long-term (>1-year postoperative) outcomes included chronic kidney disease, hypertension and glomerular filtration rate, among others. Odds ratio and mean difference with 95% confidence interval were extrapolated from available data for quantitative synthesis. Random-effects meta-analysis and meta-regression were performed according to study design and techniques. The systematic review was prospectively registered on PROSPERO (CRD42020205378). RESULTS: A total of 23 studies describing 293 cases of unilateral WT and 386 cases of bilateral WT were included in the qualitative synthesis. Overall effect estimates demonstrate that patients undergoing RN have significantly increased odds of developing abnormal kidney function (OR 4.29, 95% CI 1.02, 18.00) and lower estimated glomerular filtration rate at long-term followup (mean difference -8.99, 95% CI -16.40, -1.58) compared to those undergoing NSS. In bilateral WT, patients undergoing RN with contralateral NSS have higher odds of developing abnormal kidney function (OR 3.82, 95% CI 1.76, 8.33) and hypertension (OR 5.81, 95% CI 1.31, 25.68) compared to bilateral NSS. CONCLUSIONS: Current evidence is low quality but suggests that NSS for unilateral and bilateral WT may be associated with better kidney function or blood pressure at late followup. Further research to investigate sources of heterogeneity is recommended.

ß3-Adrenoceptor Agonist for the Treatment of Bladder Dysfunction in Children: A Systematic Review and Meta-Analysis.

PURPOSE: ß3-adrenergic receptor agonists (ß3 agonists) have been used in treatment of overactive bladder (OAB) and neurogenic detrusor overactivity (NDO) in adults. However, their use in children has only recently been approved by the U.S. Food and Drug Administration for patients with NDO. As in adults, the role of ß3 agonists in children may include conditions such as OAB. This systematic review and meta-analysis aims to understand the intended use, efficacy and safety of ß3 agonists in the pediatric population. MATERIALS AND METHODS: A literature search was performed in February 2021 across MEDLINE®, Embase®, Scopus®, the Cochrane Library and ClinicalTrials.gov. No language restrictions were placed. All records describing the clinical use of ß3 agonists in pediatric patients (<18 years of age) were included, regardless of the methodological design or outcomes assessed. The identified records were screened by 2 independent authors. The reporting was compliant with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Data extraction was performed by 2 independent reviewers, blinded to each other's extractions. The data were pooled using the fixed effects model. RESULTS: Of 367 records identified, 8 studies were included in the review (3 prospective and 5 retrospective). ß3 agonists led to improvements in both urodynamics parameters and self-reported outcomes such as incontinence. Commonly reported side effects were headaches (3%‒5.9%), constipation (3.5%‒5.7%), rhinitis/nasopharyngitis (1.7%‒5.8%) and blurred vision (1.7%‒2.9%). Clinically meaningful changes in safety outcomes (blood pressure, heart rate, electrocardiogram-related changes, liver function) were rare. Before and after ß3 agonist use, pooled effect estimates for maximum cystometric capacity for 171 patients were mean difference of +98.84 ml (95% CI 74.72, 122.96); for complete dryness, assessment of 235 patients showed a Peto odds ratio of 8.68 (95% CI 5.22, 14.45). CONCLUSIONS: ß3 agonists appear to be a promising, effective and safe alternative/adjunctive therapy in management of pediatric NDO or OAB, with improvements in both objective urodynamics parameters and subjective patient-reported outcomes following their use.

Multi-institutional Validation of Improved Vesicoureteral Reflux Assessment With Simple and Machine Learning Approaches.

PURPOSE: Vesicoureteral reflux grading from voiding cystourethrograms is highly subjective with low reliability. We aimed to demonstrate improved reliability for vesicoureteral reflux grading with simple and machine learning approaches using ureteral tortuosity and dilatation on voiding cystourethrograms. MATERIALS AND METHODS: Voiding cystourethrograms were collected from our institution for training and 5 external data sets for validation. Each voiding cystourethrogram was graded by 5-7 raters to determine a consensus vesicoureteral reflux grade label and inter- and intra-rater reliability was assessed. Each voiding cystourethrogram was assessed for 4 features: ureteral tortuosity, proximal, distal, and maximum ureteral dilatation. The labels were then assigned to the combination of the 4 features. A machine learning-based model, qVUR, was trained to predict vesicoureteral reflux grade from these features and model performance was assessed by AUROC (area under the receiver-operator-characteristic). RESULTS: A total of 1,492 kidneys and ureters were collected from voiding cystourethrograms resulting in a total of 8,230 independent gradings. The internal inter-rater reliability for vesicoureteral reflux grading was 0.44 with a median percent agreement of 0.71 and low intra-rater reliability. Higher values for each feature were associated with higher vesicoureteral reflux grade. qVUR performed with an accuracy of 0.62 (AUROC=0.84) with stable performance across all external data sets. The model improved vesicoureteral reflux grade reliability by 3.6-fold compared to traditional grading (P < .001). CONCLUSIONS: In a large pediatric population from multiple institutions, we show that machine learning-based assessment for vesicoureteral reflux improves reliability compared to current grading methods. qVUR is generalizable and robust with similar accuracy to clinicians but the added prognostic value of quantitative measures warrants further study.

Vascular hitch for paediatric pelvi-ureteric junction obstruction with crossing vessels: institutional analysis and systematic review with meta-analysis.

OBJECTIVE: To compare the outcomes for laparoscopic vascular hitch (VH) and dismembered pyeloplasty in patients with pelvi-ureteric junction obstruction (PUJO) secondary to crossing vessels (CV). PATIENTS AND METHODS: Patients who underwent laparoscopic management of CV at our institution were identified between 2008 and 2020. Baseline characteristics and outcome measures were compared between those who underwent VH and those who underwent dismembered pyeloplasty. Those who underwent VH were selected intraoperatively by identifying CV in the absence of intrinsic obstruction by assessing resolution of hydronephrosis after cranially displacing the CV away from the PUJ, followed by intraoperative fluid bolus and diuretic test. In addition, a systematic search and meta-analysis were performed in June 2020 (International Prospective Register of Systematic Reviews [PROSPERO] ID CRD42020195833). RESULTS: A total of 20 patients underwent VH and 74 dismembered pyeloplasty. On multivariate analysis, VH was associated with: shorter operative time (P = 0.001; odds ratio [OR] 0.455, 95% confidence interval [CI] 0.294-0.705) and length of stay (P = 0.012; OR 0.383, 95% CI 0.183-0.803), lower use of stents (P < 0.001; OR 0.024, 95% CI 0.004-0.141) and opioid administration (P = 0.005; OR 0.157, 95% CI 0.044-0.567). From our literature search, 194 records were identified and 18 records were included (three comparative and 16 non-comparative). Meta-analysis of the comparative studies and our institutional data showed similar success rates (relative risk [RR] 1.77, 95% CI 0.33-9.52) and complication rates (RR 0.75, 95% CI 0.20-2.82). VH was associated with shorter operative time (standardised mean difference [SMD] -1.65, 95% CI -2.58 to -0.72 h) and hospital stay (SMD -1.41, 95% CI -2.36 to -0.47 days). The VH success rates ranged from 87.5% to 100% in the identified studies. Failure of VH was associated with unrecognised concomitant intrinsic obstruction in addition to CV. CONCLUSIONS: A VH, for well-selected patients with CV without concomitant intrinsic obstruction, offers a high success rate with shorter operative times.

Pre-versus postnatal presentation of posterior urethral valves: a multi-institutional experience.

OBJECTIVE: To compare the outcomes of pre- vs postnatally diagnosed posterior urethral valves (PUV) at two large paediatric centres in North America to ascertain if the prenatal diagnosis of PUV is associated with better outcomes. PATIENTS AND METHODS: All boys with PUV were identified at two large paediatric institutions in North America between 2000 and 2020 (The Hospital for Sick Children [SickKids, SK] and Children's Hospital of Philadelphia [CHOP]). Baseline characteristics and outcome measures were compared between those diagnosed pre- vs postnatally. Main outcomes of interest included progression of chronic kidney disease (CKD), the need for renal replacement therapy (RRT), and bladder function compromise, as determined by need for clean intermittent catheterisation (CIC). Time-to-event analyses were completed when possible. RESULTS: During the study period, 152 boys with PUV were treated at the SK (39% prenatal) and 216 were treated at the CHOP (71% prenatal). At the SK, there was no difference between the pre- and postnatal groups in the proportion of boys who required RRT, progressed to CKD Stage ≥3, or who were managed with CIC when comparing the timing of diagnosis. The time to event for RRT and CIC was significantly younger for prenatally detected PUV. At the CHOP, significantly more prenatal boys required RRT; however, there was no significant difference in the age this outcome was reached. The proportion of boys managed with CIC was not different but the time to event was significantly earlier in the prenatal group. CONCLUSION: This study represents the largest multi-institutional series of boys with PUV and failed to identify any difference in the outcomes of pre- vs postnatal detection of PUV. A multidisciplinary approach with standardisation of the treatment pathways will help in understanding the true impact of prenatal/early detection on outcomes of PUV.

Comparison of outcomes of prenatal versus postnatal presentation of posterior urethral valves: a systematic review and meta-analysis.

OBJECTIVE: To determine through a comprehensive systematic review and meta-analysis the differences in the outcomes of prenatally versus postnatally diagnosed posterior urethral valves (PUV) to ascertain if prenatal detection of PUV has superior outcomes. METHODS: We conducted a systematic review and meta-analysis in March 2022 (PROSPERO ID - CRD42021243546) and included all studies that reported outcomes of prenatally and postnatally diagnosed PUV. However, for meta-analysis, only those studies that described both groups were included. The main outcomes of interest included progression of chronic kidney disease (CKD), need for renal replacement therapy (RRT) and renal transplant, and bladder dysfunction as determined by initiation of clean intermittent catheterization (CIC). Time to event analyses were completed when possible. RESULTS: The systematic review included 49 studies (3820 patients). The pooled effect estimates for progression to CKD (OR 0.75 [95% CI 0.43, 1.31]), need for RRT (OR 1.39 [95% CI 0.64, 2.99]) and need for renal transplant (OR 1.64 [95% CI 0.61, 4.42]) between prenatal and postnatal groups was not different. CICs rates were as high as 32% in the prenatal group and 22% in the postnatal group. Most studies had a moderate or serious risk of bias. CONCLUSION: The existing comparative literature on prenatal versus postnatal presentation of PUV is very heterogeneous. The diagnostic and treatment protocols have not been reported in majority of the studies. The outcome variables are also reported inconsistently. Based on the current evidence, prenatal diagnosis of PUV does not appear to improve the long-term outcomes of these patients.

Identifying urethral strictures using machine learning: a proof-of-concept evaluation of convolutional neural network model.

INTRODUCTION: To evaluate urethral strictures and to determine appropriate surgical reconstructive options, retrograde urethrograms (RUG) are used. Herein, we develop a convolutional neural network (CNN)-based machine learning algorithm to characterize RUG images between those with urethral strictures and those without urethral strictures. METHODS: Following approval from institutional REB from participating institutions (The Hospital for Sick Children [Toronto, Canada], St. Luke's Medical Centre [Quezon City, Philippines], East Virginia Medical School [Norfolk, United States of America]), retrograde urethrogram images were collected and anonymized. Additional RUG images were downloaded online using web scraping method through Selenium and Python 3.8.2. A CNN with three convolutional layers and three pooling layers were built (Fig. 1). Data augmentation was applied with zoom, contrast, horizontal flip, and translation. The data were split into 90% training and 10% testing set. The model was trained with one hundred epochs. RESULTS: A total of 242 RUG images were identified. 196 were identified as strictures and 46 as normal. Following training, our model achieved accuracy of up to 92.2% with its training data set in characterizing RUG images to stricture and normal images. The validation accuracy using our testing set images showed that it was able to characterize 88.5% of the images correctly. CONCLUSION: It is feasible to use a machine learning algorithm to accurately differentiate between a stricture and normal RUG. Further development of the model with additional RUGs may allow characterization of stricture location and length to suggest optimal operative approach for repair.

Personalized application of machine learning algorithms to identify pediatric patients at risk for recurrent ureteropelvic junction obstruction after dismembered pyeloplasty.

PURPOSE: To develop a model that predicts whether a child will develop a recurrent obstruction after pyeloplasty, determine their survival risk score, and expected time to re-intervention using machine learning (ML). METHODS: We reviewed patients undergoing pyeloplasty from 2008 to 2020 at our institution, including all children and adolescents younger than 18 years. We developed a two-stage machine learning model from 34 clinical fields, which included patient characteristics, ultrasound findings, and anatomical variation. We fit and trained with a logistic lasso model for binary cure model and subsequent survival model. Feature importance on the model was determined with post-selection inference. Performance metrics included area under the receiver-operating-characteristic (AUROC), concordance, and leave-one-out cross validation. RESULTS: A total of 543 patients were identified, with a median preoperative and postoperative anteroposterior diameter of 23 and 10 mm, respectively. 39 of 232 patients included in the survival model required re-intervention. The cure and survival models performed well with a leave-one-out cross validation AUROC and concordance of 0.86 and 0.78, respectively. Post-selective inference showed that larger anteroposterior diameter at the second post-op follow-up, and anatomical variation in the form of concurrent anomalies were significant model features predicting negative outcomes. The model can be used at https://sickkidsurology.shinyapps.io/PyeloplastyReOpRisk/ . CONCLUSION: Our ML-based model performed well in predicting the risk of and time to re-intervention after pyeloplasty. The implementation of this ML-based approach is novel in pediatric urology and will likely help achieve personalized risk stratification for patients undergoing pyeloplasty. Further real-world validation is warranted.