Multidisciplinary consensus on the classification of prenatal and postnatal urinary tract dilation (UTD classification system)

MR Imaging of the Fetal Genitourinary Tract

Fetal MR imaging overcomes many of the technical barriers of ultrasound and is an important diagnostic tool for fetal genitourinary (GU) anomalies. It is suited for evaluation of GU anomalies because of the fluid-sensitive sequences and superior soft tissue contrast. Often GU malformations are part of a multisystem genetic or congenital condition, and imaging the entire fetus with MR adds additional clarity about the extent of disease. It adds confidence to diagnoses of renal agenesis, urinary tract dilation, cystic disease, and tumors. It is particularly useful to delineate anatomy in complex GU malformations. This additional information guides counseling.

Acute kidney injury in children hospitalised for febrile urinary tract infection

AIM

To determine (i) prevalence and the risk factors for acute kidney injury (AKI) in children hospitalised for febrile urinary tract infection (fUTI) and (ii) role of AKI as indicator of an underlying VUR. AKI, in fact, is favoured by a reduced nephron mass, often associated to VUR.

METHODS

This retrospective Italian multicentre study enrolled children aged 18 years or younger (median age = 0.5 years) discharged with a primary diagnosis of fUTI. AKI was defined using Kidney Disease/Improving Global Outcomes serum creatinine criteria.

RESULTS

Of 849 children hospitalised for fUTI (44.2% females, median age 0.5 years; IQR = 1.8), 124 (14.6%) developed AKI. AKI prevalence rose to 30% in the presence of underlying congenital anomalies of the kidney and urinary tract (CAKUT). The strongest AKI predictors were presence of CAKUT (OR = 7.5; 95%CI: 3.8-15.2; p = 9.4e-09) and neutrophils levels (OR = 1.13; 95%CI: 1.08-1.2; p = 6.8e-07). At multiple logistic regression analysis, AKI during fUTI episode was a significant indicator of VUR (OR = 3.4; 95%CI: 1.7-6.9; p = 0.001) despite correction for the diagnostic covariates usually used to assess the risk of VUR after the first fUTI episode. Moreover, AKI showed the best positive likelihood ratio, positive predictive value, negative predictive value and specificity for VUR.

CONCLUSION

AKI occurs in 14.6% of children hospitalised for fUTI and is a significant indicator of VUR.

Secondary pseudohypoaldosteronism: a 15-year experience and a literature review

BACKGROUND

Secondary pseudohypoaldosteronism (S-PHA) is a rare condition resulting from renal tubular resistance to aldosterone in children with urinary tract infection (UTI) and/or nephrourological malformations. It is characterized by nonspecific symptoms but with the potential for life-threatening complications. We aim to evaluate the clinical manifestations, diagnostic approach, and therapeutic interventions in children with S-PHA, along with a review of recent publications.

METHODS

A retrospective observational descriptive study was conducted on S-PHA cases diagnosed over the last 15 years at a tertiary pediatric nephrology unit. The literature for the last 10 years was reviewed.

RESULTS

Twelve patients (10 males, 6 days to 6 months) were identified. Weight loss was the main reason for consultation (50%). Ninety-two percent of patients had an underlying nephrourological pathology and 62% concomitant confirmed UTI. Seven out of 12 children were admitted to the PICU. A subsequent extrapontine myelinolysis was observed in one patient as neurological sequelae. Twenty-one articles related to S-PHA have been identified on PubMed and Embase.

CONCLUSIONS

S-PHA should be considered in infants under 6 months of age with UTI and/or CAKUT. Obstructive anomalies and vesicoureteral reflux can be found, affecting both unilateral and bilateral systems. Early medical and surgical interventions are crucial and require close monitoring to avoid iatrogenic complications.

Ultrasound Diagnosis of Malformations of the Fetal Kidneys and Urinary System

Malformations of the fetal kidneys and urinary system are common and easily visualized and diagnosed on ultrasound. This article presents the typical sonographic findings of these abnormalities during the various stages of pregnancy. Because malformations of the urogenital tract often have an association with genetic diseases/ciliopathies, these are also discussed. To complete the article, we provide a brief overview of the normal anatomy of the kidneys and urinary system. The normal anatomy and malformations of the genitalia will not be discussed in this article due to their complexity.

Feasibility and Effectiveness of Repeat Laparoscopic Pyeloplasty for Recurrent Ureteropelvic Junction Obstruction in Pediatric Patients

Objective: To assess the outcomes of redo laparoscopic pyeloplasty (RLP) in pediatric patients with recurrent ureteropelvic junction obstruction (UPJO) in contrast to redo open pyeloplasty (ROP). In addition, evaluate the feasibility and efficacy of RLP as a treatment modality for recurrent UPJO in children. Materials and Methods: The data of 44 patients from March 2012 to March 2022, who underwent redo pyeloplasty, were retrospectively reviewed. In Group RLP, the children underwent RLP, whereas ROP was attempted in Group ROP. Demographics, clinical manifestations, surgical duration, hospitalization duration, complication rates, and treatment success were examined within the respective groups. Moreover, preoperative and postoperative measurements of anterior-posterior diameter of the renal pelvis (APD), preoperative assessment of differential renal function (DRF), and the percentage of improvement in DRF (PI-DRF) were subject to analysis. Results: The study included 28 patients who underwent RLP (Group RLP), and 16 patients who underwent ROP (Group ROP). In all cases, the Anderson-Hynes technique was employed. There was no significant difference between the two groups regarding age, body mass index, gender distribution, affected side, preoperative APD, postoperative APD, and preoperative DRF. In comparison to Group ROP, Group RLP exhibited a shorter hospitalization duration, a longer surgical procedure duration, and a higher percentage improvement in PI-DRF. The median follow-up period for Group RLP was 25 months, whereas it was 25.5 months for Group ROP. Notably, the success rates were similar between the two groups, with a success rate of 89.2% in RLP and 87.5% in ROP (p = 0.634). Conclusion: RLP has a comparable success rate to ROP and is a safe, effective, and feasible procedure for the treatment of failed pyeloplasty in children.

The conundrum of high-grade hydronephrosis with non-obstructive drainage on diuretic renography

BACKGROUND

Patients with high grade hydronephrosis (HN) and non-obstructive drainage on mercaptoacetyltriglycine (MAG-3) diuretic renography (renal scans) can pose a dilemma for clinicians. Some patients may progress and require pyeloplasty; however, more clarity is needed on outcomes among these patients.

OBJECTIVE

Our primary objective was to predict which patients with high-grade HN and non-obstructive renal scan, (defined as T ½ time <20 min) would experience resolution of HN. Our secondary objective was to determine predictors for surgical intervention.

STUDY DESIGN

Patients with prenatally detected HN were prospectively enrolled from 7 centers from 2007 to 2022. Included patients had a renal scan with T ½<20 min and Society for Fetal Urology (SFU) grade 3 or 4 at last ultrasound (RBUS) prior to renal scan. Primary outcome was resolution of HN defined as SFU grade 1 and anterior posterior diameter of the renal pelvis (APD) < 10 mm on follow-up RBUS. Secondary outcome was pyeloplasty, comparing patients undergoing pyeloplasty with patients followed with serial imaging without resolution. Multivariable logistic regression was used for analysis.

RESULTS

Of the total 2228 patients, 1311 had isolated HN, 338 patients had a renal scan and 129 met inclusion criteria. Median age at renal scan was 3.1 months, 77% were male and median follow-up was 35 months (IQR 20-49). We found that 22% (29/129) resolved, 42% of patients had pyeloplasty (54/129) and 36% had persistent HN that required follow-up (46/129). Univariate predictors of resolution were age≥3 months at time of renal scan (p = 0.05), T ½ time≤5 min (p = 0.09), SFU grade 3 (p = 0.0009), and APD<20 mm (p = 0.005). Upon multivariable analysis, SFU grade 3 (OR = 4.14, 95% CI: 1.30-13.4, p = 0.02) and APD<20 mm (OR = 6.62, 95% CI: 1.41-31.0, p = 0.02) were significant predictors of resolution. In the analysis of decision for pyeloplasty, SFU grade 4 (OR = 2.40, 95% CI: 1.01-5.71, p = 0.04) and T ½ time on subsequent renal scan of ≥20 min (OR = 5.14, 95% CI: 1.54-17.1, p = 0.008) were the significant predictors.

CONCLUSIONS

Patients with high grade HN and reassuring renal scan can pose a significant challenge to clinical management. Our results help identify a specific candidate for observation with little risk for progression: the patient with SFU grade 3, APD under 20 mm, T ½ of 5 min or less who was 3 months or older at the time of renal scan. However, many patients may progress to surgery or do not fully resolve and require continued follow-up.

Predicting clinically significant events in children with ureteropelvic junction obstruction

Introduction

Ureteropelvic junction obstruction (UPJO) syndrome is one of the most common causes of neonatal hydronephrosis. Management varies from simple monitoring to surgical intervention, with indications differing between institutions. A consensus of 8 societies recently described a new Urinary Tract Dilation (UTD) classification which aims to standardize ultrasound description of hydronephrosis, but which is also supposed to have predictive value in children with hydronephrosis. Our aim was to compare, in a monocentric prospective cohort of children with UPJO, the ability of UTD to predict the occurrence of a clinically significant event within the first year of life, as compared to anteroposterior diameter of the renal pelvis (APD).

Study design

We used a preexisting cohort of children followed in a prospective study on UPJO. A pediatric radiologist, blinded to the children's outcome, classified the last antenatal ultrasound and postnatal ultrasound according to the UTD-A and UTD-P classification. He also confirmed the APD-A and APD-P measures. We defined a clinically significant event as being: increased pelvic dilation (>5 mm) and/or the presence of a febrile urinary tract infection (fUTI) and/or impaired renal function on initial nuclear scan (<40%). We performed a ROC-AUC curve and Random Forest (RF) analysis to compare the ability of the APD-A, APD-P, UTD-A and UTD-P scores to predict a clinically significant event.

Results

The cohort included 28 children. Clinically significant events were noted in 20 out of 28 patients: 13 children presented an increase >5 mm in dilation, 6 presented an episode of fUTI and 9 had impaired function of the affected kidney. APD-A was the most effective individual criterion for predicting the occurrence of a significant clinical event (AUC = 0.867).

Conclusion

In our series, for children with UPJO, the most significant marker was prenatal APD >15 mm to predict an increase in dilation >5 mm.

Point-of-care abdominal ultrasound in pediatric and neonatal intensive care units

A spectrum of critical abdominal pathological conditions that might occur in neonates and children warrants real-time point-of-care abdominal ultrasound (abdominal POCUS) assessment. Abdominal radiographs have limited value with low sensitivity and specificity in many cases and have no value in assessing abdominal organ perfusion and microcirculation (Rehan et al. in Clin Pediatr (Phila) 38(11):637-643, 1999). The advantages of abdominal POCUS include that it is non-invasive, easily available, can provide information in real-time, and can guide therapeutic intervention (such as paracentesis and urinary bladder catheterization), making it a crucial tool for use in pediatric and neonatal abdominal emergencies (Martínez Biarge et al. in J Perinat Med 32(2):190-194, 2004) and (Alexander et al. in Arch Dis Child Fetal Neonatal Ed 106(1):F96-103, 2021).  Conclusion: Abdominal POCUS is a dynamic assessment with many ultrasound markers of gut injury by two dimensions (2-D) and color Doppler (CD) compared to the abdominal X-ray; the current evidence supports the superiority of abdominal POCUS over an abdominal X-ray in emergency situations. However, it should still be considered an adjunct rather than replacing abdominal X-rays due to its limitations and operator constraints (Alexander et al. in Arch Dis Child Fetal Neonatal Ed 106(1):F96-103, 2021). What is Known: • Ultrasound is an important modality for the assessment of abdominal pathologies. What is New: • The evidence supports the superiority of abdominal POCUS over an abdominal X-ray in emergency abdominal situations in the neonatal and pediatric intensive care units.

Primary non-refluxing megaureter: Natural history, follow-up and treatment

Primary non-refluxing megaureter (PMU) is a congenital dilation of the ureter which is not related to vesicoureteral reflux, duplicated collecting systems, ureterocele, ectopic ureter, or posterior urethral valves and accounts for 5 to 10% of all prenatal hydronephrosis (HN) cases. The etiology is a dysfunction or stenosis of the distal ureter. Most often PMU remains asymptomatic with spontaneous resolution allowing for non-operative management. Nevertheless, in selective cases such as the development of febrile urinary tract infections, worsening of the ureteral dilatation, or reduction in relative renal function, surgery should be considered.

CONCLUSION

Ureteral replantation with excision of the dysfunctional ureteral segment and often ureteral tapering is the gold-standard procedure for PMU, although endoscopic treatment has been shown to have a fair success rate in many studies. In this review, we discuss the natural history, follow-up, and treatment of PMU.

WHAT IS KNOWN

• PMU is the result of an atonic or stenotic segment of the distal ureter, resulting in congenital dilation of the ureter, and is frequently diagnosed on routine antenatal ultrasound.

WHAT IS NEW

• Most often, PMU remains asymptomatic and clinically stable, allowing for non-operative management. • Nevertheless, since symptoms can appear even after years of observation, long-term ultrasound follow-up is recommended, even up to young adulthood, if hydroureteronephrosis persists. • Ureteral replantation is the gold standard in case surgery is needed. In selected cases, however, HPBD could be a reasonable alternative.

Urinary tract dilation classification system for predicting surgical management and urinary tract infection in neonates and young infants: a systematic review and meta-analysis

BACKGROUND

The urinary tract dilation classification system has recently been developed to ensure a unified approach to describe urinary tract dilation in neonates and young infants. However, the predictive value of this system for surgical intervention or urinary tract infection (UTI) has not yet been evaluated in a meta-analysis.

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the utility of a postnatal urinary tract dilation classification system for predicting surgical management or a UTI occurrence.

MATERIALS AND METHODS

As the urinary tract dilation classification system was introduced in 2014, we searched Embase and PubMed databases for studies published between January 2014 and December 2022. Original articles that reported surgical interventions or UTI episodes according to postnatal urinary tract dilation grades were included. The pooled odds ratio (OR) was calculated, using either the fixed-effects or random-effects model, given the lower urinary tract dilation grades as the base category. The quality of the included studies was evaluated using the Newcastle-Ottawa scale.

RESULTS

Of the 285 articles reviewed, eight (comprising 2,165 children) were included in the analysis. The studies were of medium-to-high quality. Pooled analysis demonstrated that urinary tract dilation P3 (combined OR, 21.41; 95% confidence interval [CI], 15.72-29.17) and urinary tract dilation P2-P3 (combined OR, 65.17; 95% CI, 33.08-128.38) were associated with surgical intervention. The urinary tract dilation P3 (combined OR, 2.11; 95% CI, 1.56-2.85) and urinary tract dilation P2-P3 (combined OR, 3.36; 95% CI, 2.43-4.63) were associated with UTI episodes.

CONCLUSION

The postnatal urinary tract dilation classification system is useful for predicting the need for surgical management and UTI episodes in infants with hydronephrosis.

Deep learning prediction of renal anomalies for prenatal ultrasound diagnosis

Deep learning algorithms have demonstrated remarkable potential in clinical diagnostics, particularly in the field of medical imaging. In this study, we investigated the application of deep learning models in early detection of fetal kidney anomalies. To provide an enhanced interpretation of those models' predictions, we proposed an adapted two-class representation and developed a multi-class model interpretation approach for problems with more than two labels and variable hierarchical grouping of labels. Additionally, we employed the explainable AI (XAI) visualization tools Grad-CAM and HiResCAM, to gain insights into model predictions and identify reasons for misclassifications. The study dataset consisted of 969 ultrasound images from unique patients; 646 control images and 323 cases of kidney anomalies, including 259 cases of unilateral urinary tract dilation and 64 cases of unilateral multicystic dysplastic kidney. The best performing model achieved a cross-validated area under the ROC curve of 91.28% ± 0.52%, with an overall accuracy of 84.03% ± 0.76%, sensitivity of 77.39% ± 1.99%, and specificity of 87.35% ± 1.28%. Our findings emphasize the potential of deep learning models in predicting kidney anomalies from limited prenatal ultrasound imagery. The proposed adaptations in model representation and interpretation represent a novel solution to multi-class prediction problems.

Isolated Hydronephrosis and Urinary Tract Infection by Two Years of Age: A Population-Based Study

OBJECTIVE

To evaluate the risk for urinary tract infection (UTI) in infants with isolated hydronephrosis (IH).

STUDY DESIGN

A retrospective, population-based study including all infants insured by Clalit Health Services and followed from birth to age 2 years in 3 regions of central Israel. Infants were divided into 3 groups based on electronic medical record diagnoses by age 6 months: (1) control: no urological diagnosis; (2) IH; and (3) complicated urological diagnosis (CUD): any additional nephrological/urological diagnosis with/without HN. The primary outcome was a diagnosis of UTI in the first 2 years of life.

RESULTS

The cohort included 340 619 infants (52% male): 333 920 controls, 4369 with IH, and 2331 with CUD. Infants with IH were associated with a greater risk for UTI than control patients (17% vs 4%, P < .001). UTI risk for a male infant with IH was greater than for a female infant in the control group (12.6% vs 6.5%, P < .001). In a multivariable logistic regression analysis, both IH (OR 7.04; 95% CI 6.46-7.66) and CUD (OR 14.9; 95% CI 13.6-16.4) were independently associated with UTI.

CONCLUSION

Infants with IH are at a greater risk for UTI in the first 2 years of life, supporting the recommendation for a high index of suspicion for UTI in this population.

Update on imaging recommendations in paediatric uroradiology: the European Society of Paediatric Radiology workgroup session on voiding cystourethrography

Voiding cystourethrography (VCUG) is a fluoroscopic technique that allows the assessment of the urinary tract, including the urethra, bladder, and-if vesicoureteral reflux (VUR) is present-the ureters and the pelvicalyceal systems. The technique also allows for the assessment of bladder filling and emptying, providing information on anatomical and functional aspects. VCUG is, together with contrast-enhanced voiding urosonography (VUS), still the gold standard test to diagnose VUR and it is one of the most performed fluoroscopic examinations in pediatric radiology departments. VCUG is also considered a follow-up examination after urinary tract surgery, and one of the most sensitive techniques for studying anatomy of the lower genitourinary tract in suspected anatomical malformations. The international reflux study in 1985 published the first reflux-protocol and graded VUR into five classes; over the following years, other papers have been published on this topic. In 2008, the European Society of Paediatric Radiology (ESPR) Uroradiology Task Force published the first proposed VCUG Guidelines with internal scientific society agreement. The purpose of our work is to create a detailed overview of VCUG indications, procedural recommendations, and to provide a structured final report, with the aim of updating the 2008 VCUG paper proposed by the European Society of Paediatric Radiology (ESPR). We have also compared VCUG with contrast-enhanced VUS as an emergent alternative. As a result of this work, the ESPR Urogenital Task Force strongly recommends the use of contrast-enhanced VUS as a non-radiating imaging technique whenever indicated and possible.

Vesicoureteral reflux severity is not associated with unplanned urinary catheterization or length of hospital stay after ureteroneocystostomy

INTRODUCTION

Vesicoureteral reflux (VUR) is a common urologic condition affecting approximately 1% of all children. Surgical success often depends on the grade of VUR, as patients with grades 4 or 5 have been have a greater risk for postoperative complications. Unplanned urinary catheter placement (UCP) postoperatively and prolonged length of hospital stay (LOS) are indicative of unexpected complications. The association between VUR severity and such metrics remain unclear.

OBJECTIVE

The study's objective is to determine if the severity of VUR is associated with higher rates of UCP or prolonged LOS after ureteroneocystostomy (UNC).

STUDY DESIGN

The 2020 National Surgical Quality Improvement Program Pediatric database was analyzed for patients with VUR. A total of 1742 patients were initially evaluated with 1373 meeting exclusion criteria. The patients were divided into 3 groups of varying voiding cystourethrogram (VCUG) or radionuclide cystogram (RNC) severity: VCUG Grade 1 or RNC Grade 1 (Group A), VCUG Grade 2 or 3 or RNC Grade 2 (Group B), and VCUG Grade 4 or 5 or RNC Grade 3 (Group C). Basic statistical analysis was performed, and logistic regression was performed with both UCP and LOS as dependent variables.

RESULTS

Among the 1373 patients, 2.9% were included in Group A, 32.5% were in Group B, and 64.6% were in Group C. Significant differences were found among the groups for mean age, gender, inpatient status, rate of congenital malformation, ureteral stents, and ASA classification. Regarding surgical treatment, differences were also found comparing mean operative time, LOS, laterality and type of procedure, urine culture results, rates of UTI, surgical site infections, postoperative returns to the emergency department, and unplanned procedures and catheterization. Multivariate analysis demonstrated no significant association between the rate of UCP and VUR severity, while postoperative UTI and unplanned procedure were both independent factors associated with UCP postoperatively. Additionally, postoperative UTI, ASA classification, mean operation time, ureteral stent placement, unplanned procedure, and UCP were independent factors found to contribute to LOS.

CONCLUSION

Greater VUR severity does not appear to increase the need for catheterization or prolong hospital stay, while the development of a UTI postoperatively or having an additional unplanned procedure are associated with an increased likelihood of both. The postoperative course after UNC also appears to be influenced more so by other factors such as the operative approach and whether complications arise.

A machine learning algorithm predicting risk of dilating VUR among infants with hydronephrosis using UTD classification

BACKGROUNDS

Urinary Tract Dilation (UTD) classification has been designed to be a more objective grading system to evaluate antenatal and post-natal UTD. Due to unclear association between UTD classifications to specific anomalies such as vesico-ureteral reflux (VUR), management recommendations tend to be subjective.

OBJECTIVE

We sought to develop a model to reliably predict VUR from early post-natal ultrasound.

STUDY DESIGN

Radiology records from single institution were reviewed to identify infants aged 0-90 days undergoing early ultrasound for antenatal UTD. Medical records were reviewed to confirm diagnosis of VUR. Primary outcome defined as dilating (≥Gr3) VUR. Exclusion criteria include major congenital urologic anomalies (bilateral renal agenesis, horseshoe kidney, cross fused ectopia, exstrophy) as well as patients without VCUG. Data were split into training/testing sets by 4:1 ratio. Machine learning (ML) algorithm hyperparameters were tuned by the validation set.

RESULTS

In total, 280 patients (540 renal units) were included in the study (73 % male). Median (IQR) age at ultrasound was 27 (18-38) days. 66 renal units were found to have ≥ grade 3 VUR. The final model included gender, ureteral dilation, parenchymal appearance, parenchymal thickness, central calyceal dilation. The model predicted VUR with AUC at 0.81(0.73-0.88) on out-of-sample testing data. Model is shown in the figure.

DISCUSSION

We developed a ML model that can predict dilating VUR among patients with hydronephrosis in early ultrasound. The study is limited by the retrospective and single institutional nature of data source. This is one of the first studies demonstrating high performance for future diagnosis prediction in early hydronephrosis cohort.

CONCLUSIONS

By predicting dilating VUR, our predictive model using machine learning algorithm provides promising performance to facilitate individualized management of children with prenatal hydronephrosis, and identify those most likely to benefit from VCUG. This would allow more selective use of this test, increasing the yield while also minimizing overutilization.

Congenital anomalies of the kidney and urinary tract: antenatal diagnosis, management and counselling of families

Congenital anomalies of the kidney and urinary tract are collectively one of the most commonly diagnosed antenatal conditions. Clinicians have several tools available to diagnose anomalies, including imaging, biomarkers, family history and genetic studies. In certain cases, antenatal interventions such as vesico-amniotic shunting may be considered to improve postnatal outcomes.Congenital kidney anomalies detected antenatally can vary in clinical significance from almost no impact postnatally to significant morbidity and perinatal mortality. Prognosis broadly depends on kidney size, structure and amount of amniotic fluid, alongside genetics and family history, and progression on subsequent scans. It is important to counsel parents appropriately using a parent-focused and personalised approach. The use of a multidisciplinary team should always be considered.

Laparoscopic pyeloplasty for newborns with severe hydronephrosis

Aim

We aimed to investigate the short-term efficacy and safety of laparoscopic pyeloplasty for treating newborns with severe hydronephrosis due to ureteropelvic junction obstruction (UPJO).

Methods

A retrospective analysis was performed on 16 newborn patients with severe neonatal hydronephrosis who underwent laparoscopic pyeloplasty at our hospital from January 2021 to November 2022. All patients were regularly followed up. Laparoscopic pyeloplasty with double J stent placement was performed after the presence of severe hydronephrosis was confirmed.

Results

Among the 16 pediatric patients (13 males, 3 females), the left side was affected in 13 cases and the right side in 3. The average age at surgery was 9.50 (8.50-12.00) days, with an average weight of 3.30 ± 0.95 kg. Laparoscopic pyeloplasty was performed in all cases without the need for open conversion. The mean surgery duration was 292.06 ± 73.60 min, with minimal blood loss (2.50, 2.00-5.00 ml). Postoperative hospital stays averaged 13.44 ± 4.70 days. No anastomotic leakage occurred, and follow-ups at 1, 3, 6, and 12 months showed no stent displacement, except for one case where the stent was removed at 1 month, and the others at 3 months. There were no cases of worsened hydronephrosis, except for one with renal atrophy at the 6-month follow-up. Changes in renal pelvis anteroposterior diameter exhibited a time effect (F = 49.281, P < 0.001), with significant differences at 1, 3, 6, and 12 months postoperatively compared to preoperative values (P < 0.05). Notably, differences were observed between 6 and 3 months, as well as between 12 and 3 months postoperatively (P < 0.05). Similarly, renal parenchymal thickness changes showed a time effect Pediatric urology, Guangdong Women and Children Hospital, Guangzhou, China (F = 49.281, P < 0.001), with significant differences at 1, 3, 6, and 12 months postoperatively compared to preoperative values (P < 0.05). Significant differences were also noted between 6 and 1 month, as well as between 12 and 1 month postoperatively (P < 0.05). There was one case of urinary tract infection after surgery, and no case of recurrence was observed.

Conclusion

Severe neonatal hydronephrosis must be treated promptly. Laparoscopic pyeloplasty is a safe and feasible treatment with minimal complications for newborn patients with severe hydronephrosis due to UPJO.

Nuclear medicine and pediatric nephro-urology: a long-lasting successful partnership

Congenital anomalies of the kidney and urinary tract, as well as urinary infections, are very frequent in children. After the clinical and laboratory evaluation, the first imaging procedure to be done is a renal and bladder ultrasound, but afterwards, a main contribution comes from nuclear medicine. Through minimally invasive and sedation-free procedures, nuclear medicine allows the evaluation of the functional anatomy of the urinary tract, and the quantification of renal function and drainage. If pediatric dosage cards provided by scientific societies are used, radiation exposure can also be low. In the pediatric conditions previously mentioned, nuclear medicine is used both for initial diagnosis and follow-up, mostly in cases of suspicion of ureteropelvic or ureterovesical junction syndromes, as well as vesicoureteral reflux or renal scars of febrile infectious episodes. Pediatric nephro-urology constitutes a significant workload of pediatric nuclear medicine departments. The following paragraphs are a revision of the renal radiopharmaceuticals, as well as the nuclear nephro-urology procedures - dynamic and static renal scintigraphy, and direct and indirect radionuclide cystography. A summary of the techniques, main indications, interpretation criteria and pitfalls will be provided. Some future directions for the field are also pointed out, among which the most relevant is the need for nuclear medicine professionals to use standardized protocols and integrate multidisciplinary teams with other pediatric and adult health professionals that manage these life-long pediatric pathologies, which are recognized as an important cause of adult chronic kidney disease.

Role of dexamethasone in controlling the proinflammatory cytokine cascade in the first episode of paediatric acute pyelonephritis

AIM

Febrile urinary tract infection is a common bacterial infection in childhood. The kidney damage after acute pyelonephritis (APN) could be related to the stimulation of the proinflammatory response. We aimed to investigate the role of inflammatory cytokines and the effect of dexamethasone after a first episode of APN.

METHODS

Subanalysis of the DEXCAR RCT in which children with confirmed APN (1 month-14 years) were randomly assigned to receive a 3 days course of either intravenous dexamethasone or placebo. Urinary cytokine levels at diagnosis and after 72 h of treatment were measured.

RESULTS

Ninety-two patients were recruited. Younger patients, males and those with abnormalities in the ultrasound study or vesicoureteral reflux showed higher values of urinary cytokines. Patients with severe APN had higher Tumour Necrosis Factor (TNF)α levels (81.0 ± 75.8 vs. 33.6 ± 48.5 pg/mg creatinine, p = 0.015). Both intervention groups showed similar basal clinical characteristics, including urinary cytokine levels. Treatment reduced urinary cytokine levels irrespective of dexamethasone administration. Neither the intervention group nor the urinary cytokine levels modulated the development of kidney scars.

CONCLUSION

Basal urinary cytokines were associated with age, abnormal ultrasound and vesicoureteral reflux. Patients with severe APN had higher TNFa urinary levels. Administration of dexamethasone in children with APN does not improve the control of the proinflammatory cytokine cascade.

Recurrent neonatal acute kidney injury: incidence, predictors, and outcomes in the neonatal intensive care unit

OBJECTIVE

Determine recurrent neonatal acute kidney injury (rAKI) incidence, risk factors, and associated outcomes.

STUDY DESIGN

Single-center retrospective cohort of neonates admitted to the NICU 1/1/20-6/30/21. Comparisons were made between those with no AKI, single AKI episode (sAKI), and rAKI. Multivariable linear and logistic regression models were used to assess associations between rAKI and length of mechanical ventilation (LMV), length of hospitalization stay (LOS), mortality, and hypertension (HTN) at discharge.

RESULTS

The incidence of AKI in the cohort of 869 infants was 19%: 705 (81%) no AKI, 100 (12%) sAKI, 64 (7%) rAKI. Both sAKI and rAKI were independently associated with longer LMV and LOS. sAKI was independently associated with almost 4x higher odds of mortality than rAKI.

CONCLUSION

In this single center cohort of neonates, sAKI independently predicts mortality, however rAKI is independently associated with increased LMV and LOS suggesting rAKI is clinically important and warrants further study.

NUM-score: A clinical-analytical model for personalised imaging after urinary tract infections

AIM

To identify predictive variables and construct a predictive model along with a decision algorithm to identify nephrourological malformations (NUM) in children with febrile urinary tract infections (fUTI), enhancing the efficiency of imaging diagnostics.

METHODS

We performed a retrospective study of patients aged <16 years with fUTI at the Emergency Department with subsequent microbiological confirmation between 2014 and 2020. The follow-up period was at least 2 years. Patients were categorised into two groups: 'NUM' with previously known nephrourological anomalies or those diagnosed during the follow-up and 'Non-NUM' group.

RESULTS

Out of 836 eligible patients, 26.8% had underlying NUMs. The study identified six key risk factors: recurrent UTIs, non-Escherichia coli infection, moderate acute kidney injury, procalcitonin levels >2 μg/L, age <3 months at the first UTI and fUTIs beyond 24 months. These risk factors were used to develop a predictive model with an 80.7% accuracy rate and elaborate a NUM-score classifying patients into low, moderate and high-risk groups, with a 10%, 35% and 93% prevalence of NUM. We propose an algorithm for approaching imaging tests following a fUTI.

CONCLUSION

Our predictive score may help physicians decide about imaging tests. However, prospective validation of the model will be necessary before its application in daily clinical practice.

Long-term complications and outcomes of augmentation cystoplasty in children with neurogenic bladder

Augmentation cystoplasty (AC) is an effective surgical procedure for patients with neurogenic bladder whenever conservative treatments have failed. The present study aimed to determine the risks of metabolic complications, malignancy, long-term outcomes and histopathologic changes of native bladder and the augmented intestine after AC in children with neurogenic bladder. Pediatric patients < 18 years who underwent AC between 2000 and 2020 were enrolled. Early postoperative complications, long-term outcomes and histopathologic changes in mucosal biopsies of native bladder and the augmented intestine after AC were reviewed. Twenty-two patients with a mean age of 7.6 ± 4.4 years were included. The ileum was used in 19 patients and the sigmoid colon in 3 patients. The length of hospital stay was 14.8 ± 6.8 days. Post-operatively, the urinary continence rate improved from 22.7 to 81.8% (p < 0.001). Hydronephrosis resolved in 17 of 19 patients. Vesicoureteral reflux resolved in 16 (64.0%) of the refluxing ureter units and was downgraded in 7 (28.0%). Grades of hydronephrosis and reflux significantly improved following AC (p < 0.001). The estimated glomerular filtration rate also significantly increased (p = 0.012). Formation of urinary tract stones was the most frequent late complication (in 8 patients, 36.4%). Life-threatening spontaneous bladder perforation occurred in 1 patient. After a mean follow-up of 13.4 ± 5.9 years, there were no cases of mortality, new-onset symptomatic metabolic acidosis, or changes in serum electrolytes. Of the 17 patients who were followed for > 10 years, no cases of malignancy or metaplastic changes were identified in the native bladder or augmented bowel epithelium. AC is a safe and effective procedure with low surgical and metabolic complication rates. In addition, AC provides a satisfactory continence rate and long-term protection of renal function, increases functional capacity, and regresses reflux and hydronephrosis. Individualized surveillance is recommended for the early identification of urolithiasis and metabolic disturbances.

Post-obstructive diuresis after posterior urethral valve treatment in neonates: a retrospective cohort study

BACKGROUND

The management of posterior urethral valve (PUV) in neonates requires close monitoring in the intensive care unit because of the risk of post-obstructive diuresis (POD). Our aim was to describe the incidence and factors associated with POD in newborns treated for PUV.

METHODS

Retrospective analysis of the medical records of all neonates who underwent surgical intervention for PUV in our neonatal intensive care unit between January 2014 and April 2021.

RESULTS

Of the 40 patients included, 15 (37.5%) had POD defined by urine output > 6 ml.kg-1.h-1 during the first 24 h following urinary tract obstruction relief. At prenatal ultrasound examinations, oligohydramnios was more common in the group with POD than in the group without (53.3% vs. 8%, p = 0.002). Preterm birth was more frequent in neonates with POD (66.7% vs. 8%; p < 0.001). Median serum creatinine (212 [137-246] vs. 95 [77-125] µmol.l-1; p < 0.001) and urea (8.5 [5.2-12.2] vs. 4.1 [3.5-4.7] mmol.l-1; p < 0.001) concentrations on the day of obstruction relief were significantly higher in the group with POD than in the group without. After adjustment for prematurity, logistic regression models confirmed correlation between the occurrence of POD and the severity of the consequences of urethral obstruction (i.e., oligohydramnios and serum creatinine levels; ß = 2.90 [0.88; 5.36], p = 0.013 and ß = 0.014 [0.003; 0.031], p = 0.034, respectively).

CONCLUSIONS

In neonates, POD is common after the relief of PUV-related obstruction. Our findings may help to identify patients at highest risk. A higher resolution version of the Graphical abstract is available as Supplementary information.

Predictors of surgical intervention for antenatally detected ureteropelvic junction obstruction (UPJO): A prospective multivariate analysis

OBJECTIVE

We aimed to identify clinical and radiological predictors of the need for surgical intervention in infants with antenatally detected UPJO.

MATERIAL AND METHODS

We prospectively followed infants born with antenatally diagnosed ureteropelvic junction obstruction (UPJO) presented at our outpatient clinics for evidence of obstructive injury with a standard protocol with ultrasonography and renal scintigraphy. Indications for surgery included progression of hydronephrosis on serial examinations, initial differential renal function (DFR) ⩽35% or >5% loss in sequential studies, and febrile urinary tract infection (UTI). Univariate and multivariate analyses were utilized to define the predictors for surgical intervention, while the appropriate cut-off value of the initial Anteroposterior diameter (APD) was determined using the receiver operator curve analysis.

RESULTS

Univariate analysis revealed a significant association between surgery, the initial APD, cortical thickness, Society for Fetal Urology grade, UTD risk group, initial DRF, and febrile UTI (p-value < 0.05). No significant association between surgery and sex or side of the affected kidney (p-value 0.91 and 0.38, respectively). On multivariate analysis, the initial APD, initial DRF, obstructed renographic curve, and febrile UTI (p-value < 0.05) were the only independent predictors for surgical intervention. An initial APD of 23 mm can predict surgical requirement, with a specificity of 95% and sensitivity of 70%.

CONCLUSION

For antenatally diagnosed UPJO, the APD value (at the age of 1 week), DFR value (at the age of 6-8 weeks), and febrile UTI during follow-up are significant and independent predictors of the need for surgical intervention. APD, when used with a cut-off value of 23 mm, is associated with high specificity and sensitivity for predicting surgical need.

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.

Voiding Cystourethrogram Before Pyeloplasty: To Do or Not To Do?

OBJECTIVE

To assess the incidence of concomitant vesicoureteral reflux (VUR) in unilateral cases of ureteropelvic junction obstruction (UPJO) and to identify factors that predict VUR.

METHODS

Files of 381 pediatric patients who underwent unilateral pyeloplasty between 2000 and 2017 were retrospectively reviewed. A total of 270 patients with available data and ≥5 years of follow-up were eligible for this study. Demographic parameters, preoperative hydronephrosis grade, renal pelvis anteroposterior diameter (APD), renal parenchymal thickness (PT), split renal functions on MAG-3 scan and VUR status were noted. The patients were divided into two groups: those with concomitant VUR (group I, n: 24, 8.9%) and those without VUR (group II, n: 246, 91.1%).

RESULTS

Among 270 patients (205 boys, 75.9%) with a median age of 4 months (2-98), 197 (72.9%) had antenatal hydronephrosis. Median follow-up was 11 years (5-22). Among 24 patients with concurrent VUR, 6 (25%) had grade II VUR, whereas grade III-V VUR was detected in 18 (75%). Of these, 12 (50%) had ipsilateral VUR, 3 (12.5%) had contralateral, and 9 (37.5%) had bilateral VUR. In a median 137-month follow-up, spontaneous VUR resolution was observed in 6 (25%) patients, whereas 15 (62.5%) patients underwent endoscopic subureteral injection and 3 (12.5%) patients ureteroneocystostomy, respectively. Preoperative APD [35.5, (Inter Quantile Range) IQR (27.6-36.0) vs 26.5 IQR (25.0-35.0), P = .004] were significantly higher in group I, whereas group I had significantly lower PT [3.7, IQR (3.4-6.4) vs 5.8 IQR (4.4-6.1), P = .026]. Predictive factors for concomitant VUR were presentation with febrile UTI (odds ratio (OR): 2.769, P = .048), PT <3.95 mm (OR: 1.367, P = .043), and APD >28.8 mm (OR: 1.035, P = .001).

CONCLUSION

Our results indicated that concomitant VUR and UPJO might be detected in 1 out of every 11 patients undergoing pyeloplasty, while some type of surgical intervention for VUR was required in 75% of these patients. Thus, voiding cystourethrogram prior to pyeloplasty may be limited in those presenting with febrile urinary tract infection, having higher APD and lower PT on preoperative urinary ultrasonography.

Prevalence of anomalies on the routine mid-trimester ultrasound: 3172 consecutive cases by a single maternal-fetal medicine specialist

Introduction/Purpose

The routine mid-trimester fetal anatomy ultrasound (FAS) is offered to every pregnant woman and remains critical in the detection of structural fetal anomalies. Our study aimed to determine the prevalence of abnormalities on routine FAS performed by a single operator, who is an experienced sub-specialist in maternal-fetal medicine.

Methods

A retrospective analysis of all routine FAS performed a tertiary private obstetric ultrasound practice in metropolitan Sydney over a 7-year period, August 2015-July 2022. An advanced ultrasound protocol including detailed cardiac views was used in every case. Second opinion scans for suspected abnormalities were excluded. Fetal anomalies were classified into major and minor, based on the likely need for neonatal intervention.

Results

Among 14,908 obstetric ultrasound examinations, routine FAS were performed on 3172 fetuses by a single operator. More than 99% of women had screened low-risk for fetal aneuploidy. Structural anomalies were identified in 5% (157/3172) of fetuses; the prevalence of major anomalies was 1% (30/3172). Almost 60% of total anomalies were either cardiac or renal. No differences were identified in anomaly rates for singletons compared with twins (5.0% vs. 4.2%; P = 0.75). The prevalence of placenta previa and vasa previa was 10% and 0.1%, respectively.

Discussion

The prevalence of fetal anomalies on routine FAS by a single operator using a standardised protocol was higher in our practice (5%) than in previously published studies. Although most anomalies were minor, the rate of major abnormality was 1%.

Conclusion

The routine mid-trimester FAS remains an integral component of prenatal ultrasound screening.

Short Oral Antibiotic Therapy for Pediatric Febrile Urinary Tract Infections: A Randomized Trial

BACKGROUND AND OBJECTIVES

Febrile urinary tract infection (fUTI) in well-appearing children is conventionally treated with a standard 10-day course of oral antibiotic. The objective of this study is to determine the noninferiority (5% threshold) of a 5-day amoxicillin-clavulanate course compared with a 10-day regimen to treat fUTIs.

METHODS

This is a multicenter, investigator-initiated, parallel-group, randomized, controlled trial. We randomly assigned children aged 3 months to 5 years with a noncomplicated fUTI to receive amoxicillin-clavulanate 50 + 7.12 mg/kg/day orally in 3 divided doses for 5 or 10 days. The primary end point was the recurrence of a urinary tract infection within 30 days after the completion of therapy. Secondary end points were the difference in prevalence of clinical recovery, adverse drug-related events, and resistance to amoxicillin-clavulanic acid and/or to other antibiotics when a recurrent infection occurred.

RESULTS

From May 2020 through September 2022, 175 children were assessed for eligibility and 142 underwent randomization. The recurrence rate within 30 days of the end of therapy was 2.8% (2/72) in the short group and 14.3% (10/70) in the standard group. The difference between the 2 groups was -11.51% (95% confidence interval, -20.54 to -2.47). The recurrence rate of fUTI within 30 days from the end of therapy was 1.4% (1/72) in the short group and 5.7% (4/70) in the standard group (95% confidence interval, -10.4 to 1.75).

CONCLUSIONS

This study demonstrates that a 5-day course is noninferior to a 10-day course of oral amoxicillin-clavulanate.

Troubleshooting Tips for Diagnosing Complex Fetal Genitourinary Malformations

Fetal genitourinary anomalies can present a diagnostic challenge for the radiologist. The absence of a normally located kidney may represent agenesis or be secondary to a fusion or migration abnormality. A dilated renal pelvis should prompt evaluation for a specific cause, including ureteropelvic junction obstruction, reflux, or an obstructed duplicated system. Cystic parenchymal changes are characteristic of a multicystic dysplastic kidney but may also be seen in obstructive cystic dysplasia. There are numerous causes of megacystis including chromosomal (trisomy 18 syndrome), obstruction (posterior urethral valves, urethral atresia), or muscular dysfunction (prune belly syndrome, megacystis microcolon intestinal hypoperistalsis syndrome). Important mimics of a large bladder include hydrocolpos and urogenital sinus or cloacal malformation. Complications of genitourinary malformations are common and include oligohydramnios, urinary ascites, and urinoma. Making an accurate diagnosis often requires additional US views beyond those obtained in the standard fetal survey and occasionally performing fetal MRI. The appropriate use of orthogonal T2-weighted sequences, in conjunction with diffusion-weighted images for evaluation of the kidneys and gradient-recalled-echo sequences for evaluation of T1-hyperintense meconium in the colon, can play an integral role in diagnosis. Accurate diagnosis of fetal genitourinary malformations is vital to direct patient counseling and pregnancy management as outcomes are highly variable. Some conditions can be surgically corrected quite simply, some require multiple complex procedures, and some are lethal. The authors offer troubleshooting tips to narrow the differential diagnosis for four observations: unilateral absent kidney, dilated renal pelvis, cystic renal parenchyma, and megacystis and its mimics. ©RSNA, 2023 Test Your Knowledge questions are available in the Online Learning Center.

Determination of tissue tracer transit of Technetium-99m-mercaptoacetyltriglycine diuretic renography in infants with suspected ureteropelvic junction obstruction - A multicenter prospective observational study

INTRODUCTION

There is an ongoing controversy regarding management of ureteropelvic junction obstruction in infants, with a shift towards a non-operative approach. However, precise predictors of outcome are lacking. Recent studies postulated a high prognostic value of Technetium-99m-mercaptoacetyltriglycine tissue tracer transit with regard to the development of an impaired differential renal function and its potential improvement following pyeloplasty.

OBJECTIVE

To evaluate the prognostic value of Technetium-99m-mercaptoacetyltriglycine tissue tracer transit for the occurrence of changes in differential renal function in infants with suspected unilateral ureteropelvic junction obstruction in a prospective observational multicenter study.

STUDY DESIGN

Infants below 3 months of age with a unilateral isolated hydronephrosis ≥ grade 3 received ultrasound and Technetium-99m-mercaptoacetyltriglycine diuretic renography at two different time points (timepoint 1 and timepoint 2). Data were analyzed at local centers and at the study center and were collected in an internet-based database system. Tissue tracer transit was determined for each diuretic renography, inter-observer variation for tissue tracer transit and standard parameters for judgement of differential renal function development were assessed.

RESULTS

Thirty-seven patients were analyzed. Median age was 11 weeks (7-15) at timepoint 1 and 26 weeks (19-33) at timepoint 2. A delayed tissue tracer transit at timepoint 1 was not associated with deterioration of differential renal function at timepoint 2 in both, locally (10/37 cases) and centrally (4/37) analyzed cases. However, sensitivity and specificity were poor. The intraclass correlation coefficient comparing local and central findings of tissue tracer transit and renal drainage demonstrated poor or fair agreement. Analysis of standard parameters for differential renal function development revealed a prognostic value only for the dichotomized anteroposterior renal pelvic diameter (APD, p = 0.03, 95%-CI 1.2-22.2).

DISCUSSION

Regarding the primary endpoint of our study, we could not confirm the hypothesis that delayed tissue tracer transit reliably predicts a subsequent decline in differential renal function in the cohort of patients studied. Whether the low age of the patients, technical problems in the correct assessment of tissue tracer transit by the investigator in early infancy, the study design, or the parameter itself played a role is debated.

CONCLUSION

In the presented setting tissue tracer transit was not useful as a predictive parameter for deterioration of differential renal function in infants with suspected unilateral ureteropelvic junction obstruction. Sensitivity and specificity of tissue tracer transit were not sufficient for risk stratification. Improved utility of tissue tracer transit as a marker might be achieved using a different study setting.

Non-refluxing Primary Megaureter in Children Resolves From Proximal to Distal

OBJECTIVES

To evaluate a population of children with non-refluxing primary megaureter (NRPM), we investigated spontaneous resolution of ureteral dilation and the pattern (proximal to distal or distal to proximal) in which it occurs.

METHODS

From our prospectively collected prenatal hydronephrosis (HN) database (0-24 months, 2008-2017), selecting those with NRPM (n = 92). We excluded patients who underwent surgery (n = 20), children with <6 months follow-up (n = 2) and without a voiding cystourethrogram (VCUG) (n = 4). Images were segregated into 198 ureteric segments (proximal/mid/distal). We defined resolution as Society for Fetal Urology (SFU) (0/1), anteroposterior diameter (APD) <10 mm, and ureteric dilatation <5 mm. Descriptive statistics and Kaplan-Meier curves were created for time-to-resolution analyses.

RESULTS

Of 66 patients and 198 ureteral segments, median age at presentation was 2 months (0-12), 83% were male (33% circumcised). Mean APD at baseline was 11 ± 4 mm, and 79% had (SFU 3/4) HN. Mean dilatation of ureteral segments (mm) at baseline was: 9 ± 2 proximal, 9 ± 2 mid, and 11 ± 3 distal. At a median follow-up time of 26 (7-83) months, dilation of 55 (83%) proximal, 48 (72%) mid, and 22 (33%) distal ureteric segments had resolved. Overall, HN resolution occurred in 76% of patients. Resolution rates were similar for proximal/mid-ureters (83% vs 72%; P = .20); however, they were significantly different from distal segments (83% proximal vs 33% distal; 72% mid vs 33% distal, P <.01).

CONCLUSION

Our data suggest that spontaneous resolution of NRPM follows a proximal to distal progression. Distal ureteric dilatation takes up to 10 months longer to resolve compared to that of proximal and mid-ureteric segments, as well as that of the renal pelvis.

Long Term Follow-Up Of Patients With Nonrefluxing Hydronephrosis

BACKGOUND

The aim of this study is to examine the long-term prognosis of children with ureteropelvic junction obstruction-like hydronephrosis (UPJO-like HN).

PATIENTS AND METHODS

The files of children with hydronephrosis (HN) were analyzed retrospectively. Patients with vesicoureteral reflux (VUR) and other genitourinary anomalies were excluded. The final status of the HN, the need for surgery, and urinary tract infection (UTI) frequency were evaluated.

RESULTS

The study included 219 patients with 302 renal units (RU) with HN. Surgery rate was higher in RUs with larger kidney size and parenchymal thinning (p:<0.001 for both). Hydronephrosis resolved in 113 (40.2%) RUs, improved in 66 (23.3%), unchanged in 100 (35.5%) and worsened in 4 (1.4%). The frequency of recovery and improvement was found to be less in RUs with severe HN, large kidney size, and thin parenchyma. The UTI frequency was higher in severe HN group (12.2% vs 30.6% p:<0.001).

CONCLUSIONS

Children with mild HN had an excellent prognosis. Although the majority of the patients with high-grade HN had also a good prognosis, it seems important to closely follow up patients with severe HN, increased kidney size, and accompanying parenchymal thinning. Clinicians should be aware of the increased frequency of UTIs in children with severe HN.

Fetal Renal Duplicated Collecting System at 14-16 Weeks of Gestation

(1) Background: To examine the incidence of the prenatal diagnosis of the renal double-collecting system (rDCS) and describe its clinical outcome and associated genetic abnormalities. (2) Methods: This retrospective study included women who attended the obstetric clinic for early fetal anatomic sonography with findings of a renal DCS. Diagnosis was conducted by an expert sonographer using defined criteria. (3) Results: In total, 29,268 women underwent early ultrasound anatomical screening at 14-16 weeks, and 383 cases of rDCS were diagnosed (prevalence: 1:76). Associated abnormalities were diagnosed in eleven pregnancies; four had chromosomal aberrations. No chromosomal abnormalities were reported in isolated cases. Ectopic uretrocele and dysplastic kidney were diagnosed in 6 (1.5%) and 5 (1.3%) fetuses, respectively. One girl was diagnosed with vesicoureteral reflux and recurrent UTIs, and two boys were diagnosed with undescended testis. The recurrence rate of rDCS was 8% in subsequent pregnancies. (4) Conclusions: In light of its benign nature, we speculate that isolated rDCS may be considered a benign anatomic variant, but a repeat examination in the third trimester is recommended to assess hydronephrosis.

The correlation between GFR and unit renal volume in infants with hydronephrosis measured by two imaging methods

The purpose of this study was to investigate the correlation between GFR and unit renal volume in infants with congenital hydronephrosis measured by 99mTc-DMSA static renal imaging and ultrasonography. According to the classification of hydronephrosis, 38 infants aged 0-12 months with congenital hydronephrosis were divided into six groups: healthy kidney groups, mild hydronephrosis groups, and severe hydronephrosis groups. Within one week, all patients underwent ultrasound, diuretic dynamic renal imaging, static renal imaging and lateral imagings of both kidneys after static renal imaging respectively. Pediatric renal volume was calculated using the improved formula length × width × thickness × 0.674, and then the renal function in per unit volume (GFR/unit volume, ml/cm3) was obtained. All statistical analysis was done with SPSS Statistics version 24.0. The renal function in per unit volume was a minimum of 1.62 ml/cm3 in left healthy kidney in static renal imaging, but the renal function in per unit volume was a maximum value of 2.20 ml/cm3 in right healthy kidney in ultrasonography. There was a strong positive correlation observed between GFR and renal volume in left healthy kidney group and left and right kidneys with mild hydronephrosis groups (r = 0.865, r = 0.872, r = 0.822). A moderate positive correlation was found between GFR and renal volume in right healthy kidney group and left and right kidneys wih severe hydronephrosis groups (r = 0.783, r = 0.542, r = 0.798). GFR in per unit volume ranged from 1.62 to 2.20 ml/cm3 in healthy kidney, and was significantly higher in right kidney as compared to in left kidney, and also decreased with the progression of hydronephrosis.

Hyponatremia and other potential markers of ultrasound abnormalities after a first febrile urinary tract infection in children

Urinary tract infections are the initial manifestation in 30% of urinary tract malformations. Identifying these patients, who could benefit from a specific treatment, is still challenging. Hyponatremia during urinary tract infection has been proposed as a urinary tract malformation marker. We evaluate the prevalence of hyponatremia during febrile urinary tract infections and its association with subjacent urinary tract malformations. We performed a retrospective study of healthy patients under 16 years, diagnosed with a first episode of febrile urinary tract infection, who had undergone blood testing in the acute episode and at least one renal ultrasound during follow-up (January 2014-November 2020). Hyponatremia was defined as (serum sodium ≤ 130 mEq/L). According to imaging findings, we classified patients into three groups: normal kidney ultrasound, mild pelviectasis, and significant urinary tract malformation. We performed logistic regression models to identify independent risk factors for urinary tract malformation and mild pelviectasis. We included 492 patients and 2.8% presented hyponatremia. We identified normal ultrasound in 77%, mild pelviectasis in 10.8%, and urinary tract malformation in 12% of patients. We found an association between mild pelviectasis and hyponatremia [OR 6.6 (CI95% 1.6-26.6)]. However, we found no association between hyponatremia and urinary tract malformation. The parameters that were associated with malformations were presenting a non-E. coli infection, C-reactive-protein levels over 80 mg/L, and bacteremia.

CONCLUSION

Hyponatremia during the first episode of febrile urinary tract infection is present in 2.8% of patients and is associated with mild pelviectasis in imaging. However, hyponatremia does not indicate a greater need for complementary tests to screen for urinary tract malformations.

WHAT IS KNOWN

• Urinary tract infection is the first manifestation in 30% of children with urinary tract malformation. • Hyponatremia could be a marker to identify these children and guide the imaging approach.

WHAT IS NEW

• Around 12% of children with a first episode of febrile urinary tract infection have a urinary tract malformation. • Non-E. coli infection, C-reactive protein levels over 80 mg/L, and bacteremia are markers for malformations to guide diagnostic imaging tests, but hyponatremia (Na ≤ 130 mEq/l) is not a reliable marker.

Pilot study of machine learning in the task of distinguishing high and low-grade pediatric hydronephrosis on ultrasound

PURPOSE

Hydronephrosis is a common pediatric urological condition, characterized by dilation of the renal collecting system. Accurate identification of the severity of hydronephrosis is crucial in clinical management, as high-grade hydronephrosis can cause significant damage to the kidney. In this pilot study, we demonstrate the feasibility of machine learning in differentiating between high and low-grade hydronephrosis in pediatric patients.

MATERIALS AND METHODS

We retrospectively reviewed 592 images from 90 unique patients ages 0-8 years diagnosed with hydronephrosis at the University of Chicago's Pediatric Urology Clinic. The study included 74 high-grade hydronephrosis (145 images) and 227 low-grade hydronephrosis (447 images). Patients were excluded if they had less than 2 studies prior to surgical intervention or had structural abnormalities. We developed a radiomic-based artificial intelligence algorithm incorporating computerized texture analysis and machine learning (support-vector machine) to yield a predictor of hydronephrosis grade.

RESULTS

Receiver operating characteristic analysis of the classifier output yielded an area under the curve value of 0.86 (95% CI 0.81-0.92) in the task of distinguishing between low and high-grade hydronephrosis using a five-fold cross-validation by kidney. In addition, a Mann-Kendall trend test between computer output and clinical hydronephrosis grade yielded a statistically significant upward trend (p<0.001).

CONCLUSIONS

Our findings demonstrate the potential of machine learning in the differentiation between low and high-grade hydronephrosis. Further studies are warranted to validate our findings and their generalizability for use in clinical practice as a means to predict clinical outcomes and the resolution of hydronephrosis.

Influence of foetal position on the degree of isolated antenatal hydronephrosis

BACKGROUNDS

The effect of foetal position on the degree of antenatal hydronephrosis (ANH) is unknown. We hypothesized that foetal position is an important contextual factor in ANH, with consequences on prenatal counselling and postnatal management. The current study aimed to investigate the effect of foetal position on the degree of ANH.

METHODS

A retrospective study was carried out on consecutive pregnancies with isolated ANH over a 10-year period. Gestational age, foetal presentation (cephalic vs. breech), and degree of ANH (as measured by the AP diameter) were retrieved. Foetuses with other ultrasound findings of the renal tract (renal parenchymal abnormality, ureteric dilatation, or bladder abnormalities) were excluded. Logistic regression analysis was conducted to examine the relationship between the anterior-posterior diameter (APD) and the mode of presentation (cephalic or breech). A P-value of <0.05 was considered significant.

RESULTS

Initially 745 scans were identified, with 436 included in the final analysis. Overall, there was an association between foetal presentation and APD regardless of trimester, with cephalic presentations having a greater APD (OR 1.07, 95% CI 1.02-1.11, P = 0.04).

CONCLUSION

Cephalic presentations are associated with a significantly greater APD indicating that foetal position should be considered when stratifying ANH. Furthermore, foetal position may be a contributing factor in the mechanism of 'physiological' hydronephrosis.

Who needs an ultrasound? Using patient symptom questionnaire & UTI history to determine when to obtain an RBUS in children with non-neurogenic lower urinary tract dysfunction

INTRODUCTION

Non-neurogenic lower urinary tract dysfunction (LUTD) is one of the most common reasons for presentation to a pediatric urologist, affecting up to 20% of children. Predicting who will benefit from RBUS as part of their work-up is challenging as the majority will have normal imaging.

OBJECTIVE

Our objective was to assess the utility of using the Dysfunctional Voiding and Incontinence Scoring System (DVISS) and urinary tract infection (UTI) history to predict which LUTD patients were most likely to have an abnormal RBUS as well as determine a DVISS cutoff to aid in making this prediction. We hypothesized that higher DVISS scores and a positive urinary tract infection (UTI) history would be associated with increased likelihood of RBUS abnormality.

STUDY DESIGN

We retrospectively reviewed outpatients seen for LUTD from 5/2014-1/2016 who received an RBUS. Association between prior UTI, DVISS score, gender, and race and RBUS abnormality were evaluated using logistic regression analysis. Receiver operating characteristic (ROC) curves were created to evaluate the predictive model and a Youden index calculated to determine the optimal cutoff for DVISS score to predict abnormal RBUS.

RESULTS

15 of 333 patients (4.5%) had a clinically significant RBUS abnormality. Significantly more patients with abnormal RBUS had a positive UTI history and median DVISS was higher. UTI history and DVISS score were associated with RBUS abnormality whereas neither gender nor race were. A DVISS score cutoff of 12 was determined to be ideal for predicting abnormal imaging. Using DVISS≥12 and positive UTI history, patients with both risk factors were significantly more likely to have an abnormal RBUS than those with zero or one risk factor (Figure).

DISCUSSION

To the best of our knowledge this is the first study to try to identify risk factors associated with RBUS abnormality in pediatric LUTD patients and create an evidence-based approach to imaging these patients. We found both DVISS cutoff ≥12 and positive UTI history to be useful to risk stratify LUTD patients' likelihood of abnormal RBUS. Limitations include the study's retrospective nature as well as the fact the population was drawn from a tertiary care pediatric hospital with a large referral population and the fact that the decision to order an RBUS was based on individual clinician preference and decision making.

CONCLUSIONS

We found that DVISS score≥12 and UTI history are useful in guiding the decision to obtain RBUS in pediatric LUTD patients.

Antenatally detected urinary tract dilatation: long-term outcome

This review provides updated knowledge on the long-term outcomes among children with antenatally diagnosed urinary tract dilatation (UTD), previously often referred to as antenatal hydronephrosis. Different definitions of UTD exist, which makes comparison between studies and generalized conclusions difficult. Roughly, one-third of antenatally diagnosed UTD, defined as a renal pelvis anterior posterior diameter (APD) of ≥ 4 mm in the second trimester and/or ≥ 7 mm in the third trimester, will resolve before birth, another third will resolve within the first years of life, and in the remaining cases, UTD will persist or a congenital abnormality (CAKUT) will be diagnosed postnatally. The risk of a postnatal CAKUT diagnosis increases with the degree of prenatal and postnatal dilatation, except for vesicoureteral reflux (VUR), which cannot be predicted from the degree of UTD. Urinary tract infections (UTIs) occur in 7-14% of children with UTD during the first years of life. The risk of UTI is higher in children with traditional risk factors for UTI, such as dilated VUR, hydroureteronephrosis, female gender, and intact foreskin. Continuous antibiotic prophylaxis may be considered in selected patients during the first years of life. In long-term follow-ups, permanent kidney damage is diagnosed in approximately 40% of children with moderate or severe UTD, but hypertension, proteinuria, and/or reduced eGFR are uncommon (0-5%). In children with mild UTD, the long-term outcome is excellent, and these children should not be subjected to unnecessary examinations and/or follow-up.

Robot-assisted surgery versus laparoscopic surgery of ureteropelvic junction obstruction in children: a systematic review and meta-analysis

The clinical effectiveness and safety of robot-assisted laparoscopic pyeloplasty (RP) compared with laparoscopic pyeloplasty (LP) have not been clearly established in ureteropelvic junction obstruction (UPJO) children and require review. We searched in the Cochrane, MEDLINE, EMBASE, Web of Science, and CNKI database on 30 June 2022. This systematic review and meta-analysis were performed in RevMan 5.4 based on studies comparing RP versus LP in children with UPJO and subgroup analysis in children < 2 years of age has been performed. The Newcastle-Ottawa Scale was used to evaluate the studies. We included one RCT, and eighteen cohort studies, a total involving 3370 children. Compared with LP, RP showed higher surgical success rates (OR 2.57, 95%CI (1.24, 5.32), P < 0.05), lower postoperative complication rates (OR 0.61, 95%CI (0.38, 0.99), P < 0.05), shorter hospital stay (MD - 1.04, 95% CI (- 1.6, - 0.47), P < 0.05) as well as operative time (MD - 22.11, 95%CI (- 35.91, - 8.31), P < 0.05). No significant differences were detected for intraoperative complication rates or conversion to open surgery rates. RP is an alternative to UPJO with higher success rates, and less postoperative complications. Evidence on the effectiveness and safety of RP compared with LP for UPJO children is of low certainty. More quality evidence in the form of randomized controlled trials is needed to obtain more reliable analysis results.

Automated Society of Fetal Urology (SFU) grading of hydronephrosis on ultrasound imaging using a convolutional neural network

INTRODUCTION

Grading of hydronephrosis severity on postnatal renal ultrasound guides management decisions in antenatal hydronephrosis (ANH). Multiple systems exist to help standardize hydronephrosis grading, yet poor inter-observer reliability persists. Machine learning methods may provide tools to improve the efficiency and accuracy of hydronephrosis grading.

OBJECTIVE

To develop an automated convolutional neural network (CNN) model to classify hydronephrosis on renal ultrasound imaging according to the Society of Fetal Urology (SFU) system as potential clinical adjunct.

STUDY DESIGN

A cross-sectional, single-institution cohort of postnatal renal ultrasounds with radiologist SFU grading from pediatric patients with and without hydronephrosis of stable severity was obtained. Imaging labels were used to automatedly select sagittal and transverse grey-scale renal images from all available studies from each patient. A VGG16 pre-trained ImageNet CNN model analyzed these preprocessed images. Three-fold stratified cross-validation was used to build and evaluate the model that was used to classify renal ultrasounds on a per patient basis into five classes based on the SFU system (normal, SFU I, SFU II, SFU III, or SFU IV). These predictions were compared to radiologist grading. Confusion matrices evaluated model performance. Gradient class activation mapping demonstrated imaging features driving model predictions.

RESULTS

We identified 710 patients with 4659 postnatal renal ultrasound series. Per radiologist grading, 183 were normal, 157 were SFU I, 132 were SFU II, 100 were SFU III, and 138 were SFU IV. The machine learning model predicted hydronephrosis grade with 82.0% (95% CI: 75-83%) overall accuracy and classified 97.6% (95% CI: 95-98%) of the patients correctly or within one grade of the radiologist grade. The model classified 92.3% (95% CI: 86-95%) normal, 73.2% (95% CI: 69-76%) SFU I, 73.5% (95% CI: 67-75%) SFU II, 79.0% (95% CI: 73-82%) SFU III, and 88.4% (95% CI: 85-92%) SFU IV patients accurately. Gradient class activation mapping demonstrated that the ultrasound appearance of the renal collecting system drove the model's predictions.

DISCUSSION

The CNN-based model classified hydronephrosis on renal ultrasounds automatically and accurately based on the expected imaging features in the SFU system. Compared to prior studies, the model functioned more automatically with greater accuracy. Limitations include the retrospective, relatively small cohort, and averaging across multiple imaging studies per patient.

CONCLUSIONS

An automated CNN-based system classified hydronephrosis on renal ultrasounds according to the SFU system with promising accuracy based on appropriate imaging features. These findings suggest a possible adjunctive role for machine learning systems in the grading of ANH.

Percutaneous Nephrostomy in Neonates and Young Infants

PURPOSE

To describe a single-center experience of placing percutaneous nephrostomy (PCN) tubes in neonates and young infants aged ≤3 months.

MATERIALS AND METHODS

This retrospective study evaluated PCN placement during a 19-year period. Medical records were reviewed for patient demographics, indications, procedure details, catheter-related adverse events, and outcomes. A total of 45 primary PCN insertions were attempted in 29 children (median age, 11 days [range, first day of life to 3 months]; median weight, 3.5 kg [range, 1.4-7.0 kg]). Salvage procedures resulted in 13 secondary catheters in 6 children. The most common indication was ureteropelvic junction obstruction (40.0%), and the most common urinary tract dilation classification was P3 (88.9%).

RESULTS

Technical success for primary placements was 95.6%; both technical failures were due to loss of access in the same patient. Of primary placements, 76.7% were electively removed, 6.9% were dislodged but not replaced, and the remaining 16.3% required salvage procedures. Mechanical adverse events occurred in 20.9% of primary and 53.8% of secondary catheters, including partial retraction, complete dislodgement, and occlusion. Urinary tract infections (UTIs) occurred in 18.6% of primary and 15.4% of secondary catheters. Urosepsis occurred in 2.3% of primary and 7.7% of secondary catheters. Median primary catheter dwell time was 41 days (range, 1-182 days) and median secondary catheter dwell time was 31 days (range, 10-107 days).

CONCLUSION

PCN placement in neonates and young infants has a high technical success rate, although not without particular procedural and management challenges of catheter malfunction and UTI.

Vesicoureteral Reflux: Current Care Trends and Future Possibilities

Although investigations over the past 2 decades have improved our understanding of the natural history of vesicoureteral reflux (VUR) and helped identify those at higher risk of both VUR itself as well as its potential severe sequelae, debate exists regarding key aspects of care, including when to perform diagnostic imaging and which patients benefit from continuous antibiotic prophylaxis. Artificial intelligence and machine learning have the potential to distill large volumes of granular data into practical tools that clinicians can use to guide diagnosis and management decisions. Surgical treatment, when indicated, remains highly effective and is associated with low morbidity.

Kidney Ultrasonography After First Febrile Urinary Tract Infection in Children: A Systematic Review and Meta-analysis

Importance

Controversy exists on the clinical utility of kidney ultrasonography after first febrile urinary tract infection (UTI), and clinical practice guideline recommendations vary.

Objective

To determine the prevalence of urinary tract abnormalities detected on kidney ultrasonography after the first febrile UTI in children.

Data Sources

The MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Central Register of Controlled Trials databases were searched for articles published from January 1, 2000, to September 20, 2022.

Study Selection

Studies of children with first febrile UTI reporting kidney ultrasonography findings.

Data Extraction and Synthesis

Two reviewers independently screened titles, abstracts, and full texts for eligibility. Study characteristics and outcomes were extracted from each article. Data on the prevalence of kidney ultrasonography abnormalities were pooled using a random-effects model.

Main Outcomes and Measures

The primary outcome was prevalence of urinary tract abnormalities and clinically important abnormalities (those that changed clinical management) detected on kidney ultrasonography. Secondary outcomes included the urinary tract abnormalities detected, surgical intervention, health care utilization, and parent-reported outcomes.

Results

Twenty-nine studies were included, with a total of 9170 children. Of the 27 studies that reported participant sex, the median percentage of males was 60% (range, 11%-80%). The prevalence of abnormalities detected on renal ultrasonography was 22.1% (95% CI, 16.8-27.9; I2 = 98%; 29 studies, all ages) and 21.9% (95% CI, 14.7-30.1; I2 = 98%; 15 studies, age <24 months). The prevalence of clinically important abnormalities was 3.1% (95% CI, 0.3-8.1; I2 = 96%; 8 studies, all ages) and 4.5% (95% CI, 0.5-12.0; I2 = 97%; 5 studies, age <24 months). Study recruitment bias was associated with a higher prevalence of abnormalities. The most common findings detected were hydronephrosis, pelviectasis, and dilated ureter. Urinary tract obstruction was identified in 0.4% (95% CI, 0.1-0.8; I2 = 59%; 12 studies), and surgical intervention occurred in 1.4% (95% CI, 0.5-2.7; I2 = 85%; 13 studies). One study reported health care utilization. No study reported parent-reported outcomes.

Conclusions and Relevance

Results suggest that 1 in 4 to 5 children with first febrile UTI will have a urinary tract abnormality detected on kidney ultrasonography and 1 in 32 will have an abnormality that changes clinical management. Given the considerable study heterogeneity and lack of comprehensive outcome measurement, well-designed prospective longitudinal studies are needed to fully evaluate the clinical utility of kidney ultrasonography after first febrile UTI.

Ureteropelvic Junction Obstruction/Hydronephrosis

Congenital hydronephrosis can be classified and managed based on the Urinary Tract Dilation consensus scoring system. Ureteropelvic junction obstruction is one of the most common causes of hydronephrosis in the pediatric population. Although most cases can be managed conservatively with follow-up and serial imaging, some patients need surgical repair because of renal function deterioration, infections, or symptoms. Additional research to create predictive algorithms or develop noninvasive biomarkers for renal deterioration is necessary to better identify surgical candidates. The robotic-assisted approach for pyeloplasty is becoming increasingly widespread and associated with shorter hospital stay, high success rates, and low complication rates.

Comparative Analysis of Surgical Outcomes of Flexible Ureteroscopy and Da Vinci Robotic Surgery in Community Patients with Renal Pelvic Stones Larger than 2 cm

Background and Objectives: This study evaluated and compared the surgical outcomes of retrograde intrarenal surgery (RIRS) lithotripsy versus robot-assisted laparoscopic pyelolithotomy (RAPL) in community patients with renal pelvic stones larger than 2 cm. Materials and Methods: A total of 77 patients who underwent RIRS (RIRS group, n = 50) or RAPL (RAPL group, n = 27) at our institution between December 2016 and July 2022 were recruited. A single surgeon performed all surgical operations. Preoperative, operative, and postoperative data were recorded. The study evaluated various clinical outcomes, namely, urinary tract infections, analgesic use, emergency room readmissions, stone clearance rates, surgical complications, and medical expenditures associated with the treatment courses, and compared them between the groups. Results: The RAPL group had a larger mean stone diameter and higher degree of hydronephrosis than the RIRS group did. The RIRS group had superior outcomes regarding operative time, length of postoperative hospital stay, surgical wound pain, and medical expenditures. Regarding postoperative outcomes, comparable rates of postoperative urinary tract infection, prolonged analgesic use, and emergency room readmissions were observed between the groups. However, the RAPL group had a higher stone clearance rate than the RIRS group did (81.5% vs. 52.0%, p = 0.014). Conclusions: For the surgical treatment of renal pelvis stones larger than 2 cm, RAPL has a superior stone clearance rate than RIRS; however, RIRS achieves superior outcomes in terms of medical expenditures, length of hospital stay, and surgical wound pain. Both procedures were equally safe.

Are weight or age limits for pediatric laparoscopic pyeloplasty? Results of a multicentric study

INTRODUCTION

Anderson-Hynes pyeloplasty is the technique of choice for the treatment of pyeloureteral junction obstruction (PUJO) with an excellent success rate. Minimally invasive surgery has become the standard of care for the management of PUJO in children. Although it has been comparable to the open approach at all levels, its diffusion or employment in younger children has not been widely adopted. Our aim is to evaluate laparoscopic pyeloplasty outcomes from international academic centers in children under 1 year of age, focusing on feasibility and outcomes including possible complications.

MATERIALS AND METHODS

This is review of consecutive infants under 1 year of age who underwent laparoscopic pyeloplasty between 2009 and 2018 with more than 12 months of follow-up. Seven different training centers with different backgrounds participated in this study. Evaluation was carried out with ultrasound and renogram before and after surgery. Demographic data, perioperative characteristics, complications, and results are described and analyzed.

RESULTS

Over 9 years, 124 transperitoneal laparoscopic Anderson-Hynes pyeloplasties were performed on 123 children under 1 year of age; 88 males and 35 females, with 1 case of bilateral PUJO. Of the 124 renal units, 86 were left-sided. Mean age at surgery was 6.6 months (1 week-12 months), with 56% (n = 70) done before 6 months of age. Mean weight at surgery was 6.8 kg (3-12 kg), with 59% (n = 73) weighing less than 8 kg. Mean operative time (skin-to-skin) was 150 min (75-330 min). After a mean follow-up of 46 months (12-84 months), 12 (9%) patients developed complications, with only 1 needing a redo pyeloplasty also done laparoscopically. One child, with deterioration in renal function, underwent nephrectomy.

CONCLUSION

Laparoscopic pyeloplasty under 1 year of age and/or less than 12 kilos is feasible with lower complication rate. Furthermore, age younger than 6 months and weight less than 8 kg are no longer limiting factors for a successful pyeloplasty as shown by this multicentre study.

Staphylococcus Epidermidis as a Uropathogen in Children

Historically, Staphylococcus epidermidis has been considered a contaminant when grown on urine cultures. However, a growing body of literature suggests that S. epidermidis can cause urinary tract infections (UTIs) in children with anatomic variants or a history of instrumentation. In this case report, we describe a previously healthy child who presented with symptoms of UTI and urine cultures grew this uropathogen. The patient was screened for anatomic abnormalities and none were found; nonetheless, appropriate treatment should be initiated even if no underlying pathology is found.