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.

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.

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.

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.

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.

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.

Does VURD syndrome impact voiding efficiency in posterior urethral valves?

INTRODUCTION: There is debate regarding the effect of VURD syndrome, consisting of vesicoureteral reflux (VUR) and ipsilateral kidney dysplasia, on long-term outcomes in boys with posterior urethral valve (PUV). Here, we assessed whether VURD syndrome played a "protective" role on long-term bladder outcomes and voiding efficiency in boys with PUV. MATERIALS AND METHOD: A retrospective chart review was conducted for toilet-trained children with PUV managed at our institution between 2000 and 2022, only excluding cases without recorded uroflowmetry studies. Patients were stratified by VUR status and by the presence of VURD syndrome (high-grade VUR + ipsilateral kidney dysplasia). Outcomes included initial and final uroflowmetry parameters, and initiation of clean-intermittent catheterization (CIC). RESULTS: We identified a total of 101 patients who met study inclusion criteria, with an overall median follow-up of 114 months (IQR 67, 169). The median age of first and last uroflowmetry was 57 months (IQR 48, 82) and 120 months (IQR 89, 160), respectively. Patients with VURD syndrome had similar flow velocity, post-void residuals, and bladder voiding efficiency to other PUV patients at last follow-up uroflowmetry. On survival analysis, patients with VURD syndrome had no significant difference in risk of requiring CIC compared to patients without pop-offs (p = 0.06). DISCUSSION: Like more contemporary studies on pressure pop-offs, we show that this population is not at higher risk of poorer voiding and intermittent catheterization than others. VURD syndrome does not confer protection against poorer bladder function. Instead, our study suggests an independent association between kidney dysplasia and bladder outcomes which requires further attention. CONCLUSIONS: Among boys with PUV, VURD syndrome was not associated with significantly different uroflowmetry findings or rates of CIC by last follow-up.

Healthcare utilization during transition to adult care in patients with spina bifida A population-based, longitudinal study in Ontario, Canada.

INTRODUCTION: Individuals with spina bifida (SB) may experience negative health outcomes because of an informal transition from pediatric to adult care that results in using the emergency room (ER ) for non-acute health problems. METHODS: We conducted a retrospective, population-based cohort study of all people with SB in Ontario, Canada turning 18 years old between 2002 and 2011. These patients were followed for five years before and after age 18. Primary outcome was the annual rate of ER visits. Secondary outcomes included rates of hospitalization, surgery, primary care, and specialist outpatient care. We estimated the association between age and primary and secondary outcomes using negative binomial growth curve models, adjusting for patient-level baseline covariates. RESULTS: Among the 1215 individuals with SB, there was no trend of ER visits seen with increasing age (relative risk [RR ] 0.99, 95% confidence interval [CI] 0.98-1.02); however, there was a significant increase in the rate of ER visits associated with turning 18 years (RR 1.14, 95% CI 1.03-1.27). Turning 18 years old was also associated with a decreased rate of hospital admissions (RR 0.79, 95% CI 0.66-0.95) and no change in surgeries (RR 0.80, 95% CI 0.64-1.02). Visits to primary care physicians remained stable over the same period (RR 0.96, 95% CI 0.90-1.01), while visits to SB-focused specialists decreased after age 18 (RR 0.81, 95% CI 0.75-0.87). CONCLUSIONS: In patients with SB, the rate of ER visits increased significantly at 18 years old, while hospital admissions and specialist physician visits decreased at the same time. Models of transitional care can aim to reduce non-urgent ER visits and facilitate regular specialist care.

Outcomes according to treatment using an established protocol in patients with bilateral Wilms' tumor: A national Canadian population-based study.

BACKGROUND: Bilateral Wilms tumor (BWT) is a rare entity. The goal of this study is to report outcomes (overall and event-free survival, OS/EFS) of BWT in a large cohort representative of the Canadian population since 2000. We focused on the occurrence of late events (relapse or death beyond 18 months), as well as outcomes of patients treated following the only protocol specifically designed for BWT to date, AREN0534, compared to patients treated following other therapeutic schemes. METHODS: Data was obtained for patients diagnosed with BWT between 2001 and 2018 from the Cancer in Young People in Canada (CYP-C) database. Demographics, treatment protocols, and dates for events were collected. Specifically, we examined outcomes of patients treated according to the Children's Oncology Group (COG) protocol AREN0534 since 2009. Survival analysis was performed. RESULTS: 57/816 (7%) of patients with Wilms tumor had BWT during the study period. Median age at diagnosis was 2.74 years (IQR 1.37-4.48) and 35 (64%) were female; 8/57 (15%) had metastatic disease. After a median follow-up of 4.8 years (IQR 2.8-5.7 years, range 0.2-18 years), OS and EFS were 86% (CI 73-93%) and 80% (CI 66-89%), respectively. Less than 5 events were recorded after 18 months from diagnosis. Since 2009, patients treated according to the AREN0534 protocol had a statistically significant higher OS compared to patients treated with other protocols. CONCLUSIONS: In this large Canadian cohort of patients with BWT, OS and EFS compared favorably to the published literature. Late events were rare. Patients treated according to a disease-specific protocol (AREN0534) had improved overall survival. TYPE OF STUDY: Original article. LEVEL OF EVIDENCE: Level IV.

Assessing the role of upside-down (inverted) renal allografts in pediatric kidney transplantation: a propensity-score matched analysis.

OBJECTIVE: To evaluate the implications of inverted (upside-down) kidney configuration in pediatric renal transplantation employing a comparative analysis with at least 1-year follow-up. METHODS: Patients who underwent kidney transplantation at our institution between January 2011 and June 2021 were reviewed. Patients who had an inverted renal transplant were propensity-score matched (PSM) in 1:2 ratio with those who had traditional orientation transplant. The outcomes assessed included delayed graft function (DGF), urine leak, lymphocele, rejection, allograft calculus, ureteric stricture, and nadir creatinine. RESULTS: A total of 24 patients with inverted orientation were identified. Following PSM, 41 patients were matched, with exclusions due to incompatible propensity scores. Baseline characteristics were appropriately matched, and no significant differences were noted between the two groups. There were no differences in: delayed graft function (0/24 vs. 3/41, p = 0.290), urine leak (3/24 vs. 2/41, p = 0.350), lymphocele (2/24 vs. 4/41, p = 1.000), rejection (3/24 vs. 5/41, p = 1.000), graft calculus (2/24 vs. 0/41, p = 0.133), and ureteric stricture (0/24 vs. 2/41, p = 0.527). The two cases of renal calculus seen in the inverted transplant group occurred on post-operative day 13 and 1584, both were managed without complications. There was no difference in nadir creatinine (median 34umol/L IQR23-57 vs. 35 umol/L IQR 20-50, p = 0.624) or time to nadir creatinine (8 days IQR 6-12 vs. 8 days IQR 7-28, p = 0.315). CONCLUSION: Inverting a renal allograft does not appear to significantly contribute to increased risk of post-operative adverse outcomes. When aiming to achieve the best anatomical placement to secure a comfortable vascular anastomosis, inverting the allograft should be considered.

Nephron-sparing surgery for renal cell carcinoma in children and young adults: A systematic review.

OBJECTIVE: To determine the patient characteristics and role of nephron-sparing surgery (NSS) in the treatment of children and young adults with renal cell carcinoma (RCC). METHODS: A systematic search of Embase, MEDLINE, and Scopus databases was conducted in December 2021 according to Cochrane collaboration recommendations. All included manuscripts were assessed for patient characteristics and all reported outcomes for patients undergoing partial nephrectomy (PN), and radical nephrectomy (RN) outcomes were abstracted as a comparison group. Primary outcomes included surgical outcomes, overall survival, kidney outcomes. Outcomes were pooled with weighted mean and ranges. Meta-analysis was not performed given study quality. This systematic review was prospectively registered on PROSPERO (CRD42022300261). RESULTS: We found a total of 16 studies describing 119 and 559 unique patients undergoing PN and RN, respectively, with a mean age of 12.2 years and mean follow-up of 59.1 months. The mean tumor size for patients undergoing PN was 3.5 cm. Of the 113 patients undergoing PN with available data, 109 were alive at follow-up (98%). No studies reported long-term kidney outcomes, and four studies reported surgical outcomes. All studies had at least moderate risk of bias. CONCLUSIONS: The use of NSS in children and young adults with RCC is feasible in selected patients. However, small sample sizes, confounding, and low study quality limit clinical recommendation on NSS in this population. There are significant opportunities for future research on the use of NSS in RCC, especially with systematic reporting of oncological, kidney, and surgical outcomes.

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.

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.

Anesthetic and surgical considerations for staged bilateral nephrectomies in a pediatric patient: A case report / Consideraciones anestésicas y quirúrgicas en nefrectomía bilateral en dos tiempos en un paciente pediátrico: Reporte de caso

Abstract We present a 9-year-old patient with end-stage renal disease, on peritoneal dialysis, who underwent a staged prone retroperitoneoscopic bilateral nephrectomy. Bilateral nephrectomy was indicated in preparation for renal transplant in the context of genetic predisposition malignancy when immunosuppressed. The two mirror-image surgeries enable the comparison of the anesthetic management and outcomes in a single patient. Features of interest to anesthesiologists include approach to a child with chronic kidney disease, different requirements for intraoperative antihypertensives; pain management strategies, including a comparison of erector spinae plane block with and without adjunct dexmedetomidine; anesthetic management of retroperitoneoscopic pediatric surgery and the first description of using a Foley bag attached to a peritoneal dialysis catheter to aid in diagnosis and repair of posterior peritoneal cavity entry.

Resumen Se presenta un paciente de 9 años de edad con enfermedad renal terminal, en diálisis peritoneal, quien se sometió a nefrectomía bilateral retroperitoneoscópica estadificada en posición prona. Se indicó la nefrectomía bilateral en preparación para trasplante renal en el contexto de predisposición genética hacia desarrollar una patología maligna al estar inmunosuprimido. Las dos cirugías en espejo permiten hacer una comparación del manejo anestésico y de los desenlaces en un mismo paciente. Las características de interés para los anestesiólogos incluyen el abordaje de un niño con enfermedad renal crónica, con requisitos diferentes de antihipertensivos intraoperatorios; estrategias para el manejo del dolor, incluyendo una comparación de bloqueo del plano del erector espinal con y sin dexmedetomidina adyuvante; manejo anestésico de cirugía pediátrica retroperitoneoscópica y la primera descripción del uso de una bolsa Foley conectada a un catéter de diálisis peritoneal para ayudar en el diagnóstico y la reparación de la entrada de la cavidad peritoneal posterior.

Scoping review of recent evidence on the management of pediatric urolithiasis: summary of meta-analyses, systematic reviews and relevant randomized controlled trials.

This scoping review aimed to evaluate and summarize the recent 10 year pediatric urolithiasis literature with a particular focus on systematic reviews, randomized-controlled trials (RCT) and meta-analysis. The systematic literature search performed on September 1, 2021, restricted to the recent 10 years, focused on pediatric urolithiasis that are RCTs, meta-analysis and systematic reviews. The summarized literature included etiology, diagnostics, medical and surgical management. GRADE criteria are used to evaluate and standardize the reporting of evidence quality. A total of 33 relevant articles were included. The recent high-level studies included topics of genetic and diet association with pediatric stone formation, diagnostic assessment, medical management intervention including medical dissolution and expulsion therapy. The study extended to include the efficacy and safety of extracorporeal lithotripsy, percutaneous nephrolithotomy and retrograde intrarenal surgery. However, evidence quality was ranked "very-low" or "low". Based on the GRADE criteria downgrading of the quality level was due to heterogeneity and low precision. A majority of the RCTs were categorized as having a "high" to "uncertain" risk of bias. The relevant RCTs, meta-analyses and systematic reviews within the past decade are of low quality. Consequently, the research provided no clear evidence-based recommendations for managing pediatric urolithiasis. More rigorous research and high-quality studies are needed to determine the best practices.

Comparison of continuous and interrupted suture techniques in pyeloplasty: a systematic review and meta-analysis.

Pelvi-ureteric anastomosis is a critical step to ensure good outcome of pyeloplasty. Continuous suturing technique, especially for laparoscopic surgeries, may offer faster operative time while allowing water-tight anastomosis and remains an alternative to interrupted suturing technique. There has been mixed data on comparison of outcomes of continuous and interrupted suturing techniques. This systematic review and meta-analysis aim to assess the outcomes of pyeloplasty based on continuous and interrupted suturing techniques. Following protocol registration on PROSPERO (CRD42021269706), a systematic review was performed in accordance with Cochrane Collaboration. A literature search was performed in September 2021 across Medline, EMBASE, Scopus, Cochrane Library, and ClinicalTrials.gov. Records comparing pyeloplasty outcomes between continuous and interrupted suture techniques were included. Five studies were identified for inclusion (2 prospective, 3 retrospective). Three studies involved pediatric patients. Three studies exclusively assessed laparoscopic technique. Four outcomes were meta-analyzed: operative time, length of stay, complications, and pyeloplasty failure. Interrupted sutures had longer OR time (mean difference 33.14 min [95% CI 29.35-36.94], p < 0.0001) and length of stay (mean difference 1.08 days [95% CI 0.84-1.32], p < 0.0001). However, there were similar complication (OR 1.73 [95% CI 0.98-3.06], p = 0.06) and failure rates (OR 1.21 [95% CI 0.43-3.43], p = 0.71) between the two suture types. The overall risk of bias in the studies was high. While limited by the number of studies available, continuous sutures for pelvi-ureteric anastomosis appear to confer benefits of faster operative time and decreased length of stay without increasing complication rates or failures.

Attaining competency and proficiency in open pyeloplasty: a learning curve configuration using cumulative sum analysis.

INTRODUCTION: The learning curves for minimally invasive pyeloplasty techniques have been described in the past. However, the learning curve in achieving competency in open pyeloplasty has not been described. Hence, we aim to evaluate a single surgeon series of open pyeloplasty technique using the cumulative sum (CUSUM) methodology. METHODS: We retrospectively reviewed all open pyeloplasties performed by a single surgeon (AJL) between January 2008 and March 2020. Collected variables included: sex, age at surgery, operative time, hospital stay, pre-operative ultrasound, pre-operative nuclear scans, pre-operative anteroposterior diameter, associated anomalies, laterality (left or right), type of stent, pre-operative split renal function, and duration of follow-up. A CUSUM analysis was used: the highest peak, plateau and downward trends for complications (defined as Clavien-Dindo classification ≥ 3b) were identified on the plot and set as the transition points between five phases (learning, competency, proficiency, case-mix, and mastery). RESULTS: Based on the CUSUM analysis, the index surgeon reached the competency phase after performing their 13th open pyeloplasty and became proficient after the 70th case. In the case-mix phase (104th-126th cases), where the surgeon may be performing more complex cases while increasing trainee involvement, there was a slight increase in complication rates. After the 126th case, the surgeon entered the mastery phase, where there was consistent decreasing trend in complications. CONCLUSIONS: Surgeons performing open pyeloplasty in children following completion of their surgical training will continue to learn through their early cases until achieving competency. Technical competency may be reached after the 13th case. In this report, we looked at the number of cases to become proficient in open pyeloplasty procedure in children. A surgeon may achieve technical proficiency in the procedure after their 13th case.